Prevalence of hypertension in the Gambia and Sierra Leone,western Africa: a cross-sectional study

Hypertension (HTN) is a chronic, slowly progressive disease affecting about one billion people globally and leading to about 7.1 million deaths annually. People of African origin may be particularly susceptible to hypertension.1-3 Defined as a sustained systolic blood pressure (SBP) above 140 mmHg, a diastolic blood pressure (DBP) above 90 mmHg or both, the aetiology of HTN can be classified as primary or secondary. While there is no known cause for primary (essential) HTN, which accounts for 90–95% of cases, the remaining 5–10% of cases is defined as secondary HTN and is caused by other disease conditions, which may affect the renal, circulatory, endocrine or other organ systems.Many factors are associated with, and may contribute to the development and persistence of primary HTN, including obesity, stress, smoking,4 low potassium intake, high sodium (salt) and alcohol intake,5,6 familial and genetic influences,7,8 and low birth weight.9 On the other hand, hyperthyroidism, hypothyroidism and other conditions causing hormonal changes may be associated with primary pulmonary HTN.10,11 Regardless of the cause, the consequences of HTN include renal failure, heart failure, myocardial infarction, pulmonary oedema and stroke.12Given these undesirable outcomes, treatment and prevention have assumed increasing emphasis in the management of HTN. Modification of risk factors can be achieved by reducing body weight and decreasing sugar intake, along with lowering alcohol consumption,13,14 as well as reducing salt intake and increasing potassium intake.15,16 Secondary HTN is managed by treating the underlying cause. Drugs available for the treatment of HTN, whether primary or secondary, include calcium-channel blockers (CCB), angiotensin converting enzyme inhibitors (ACEI), angiotensin receptor blockers (ARB), diuretics, α-blockers and β-blockers.Race and ethnicity may influence pathogenesis, prevalence and treatment of HTN,17 perhaps through genetic influences. As a consequence, HTN remains one of the most common CVDs in Africa and one of the most frequent causes of death in the sub-Saharan African region.18,19 In 2000, the rate of HTN in sub-Saharan Africa was reported to be 26.9% in males and 28.3% in females.20 Low socio-economic status (SES) may additionally play an important role in the high prevalence of HTN in western and sub-Saharan Africa.A cross-sectional survey in Tanzania revealed that treatment rates for HTN were very low, especially among people with low SES.21 Low SES led to inadequate education levels as a factor correlating with a higher blood pressure (BP) in adults and resulted in a low treatment rate for HTN due to monetary issues.22Stress, in addition, was another factor related to HTN prevalence, especially in Africa.23 It has been shown that psychosocial stress affects the L-arginine/nitric oxide (NO) system, with a higher susceptibility in black Africans, which in turn contributes to a higher risk of CVD in those individuals.24Therefore, a multiplicity of factors may be associated with and contributing to a high prevalence of HTN among Africans. The current study was undertaken to determine and quantitate the prevalence of HTN in two countries in western sub-Saharan Africa, namely, the Gambia and Sierra Leone.     

Impact of prehypertension on left ventricular mass and QT dispersion in adult black Nigerians

The heterogeneity of individuals with blood pressure (BP) < 140/90 mmHg in terms of cardiovascular (CV) risk was reported as early as 1939 by Robinson and Brucer.1 BP in the range of 120–139/80–89 mmHg (labelled then as prehypertension) was observed to be associated with high risk of progression to hypertension (HT) and cardiovascular disease (CVD) later in life when compared with BP < 120/80 mm Hg.1The term prehypertension was adopted in May 2003 by the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation and Treatment of High blood Pressure (JNC-7) to describe BP range of 120–139/80–89 mmHg.2 The resuscitation of this terminology/concept in JNC-7 was a sequel to the documentation of a higher morbidity in individuals with prehypertension in landmark publications.3-5 Prehypertension (PHT) was defined in JNC-7 not only to emphasise the excess risk associated with BP in this range, but also to focus increased clinical and public health attention on prevention.2,6,7Prevalence rates of PHT among adults in the United States, Ghana and northern Nigeria have been reported to be 31, 40 and 58.7%, respectively.7-9 In most studies, including the ones above, PHT was more prevalent than hypertension.7-9 Though PHT is associated with increased risk of major CV events independently of other CV risk factors,10 most individuals (90%) with PHT have at least one cardiovascular risk factor such as dyslipidaemia, abdominal obesity, hyperinsulinaemia, impaired fasting glucose levels, insulin resistance, a prothrombotic state, tobacco use, endothelial dysfunction, and impaired vascular distensibility.6,7,9,10QT interval dispersion (QTd) (the difference between the longest and the shortest QT intervals on a surface ECG), when excessive, is associated with increased risk of cardiovascular morbidity and mortality in population studies, and many clinical conditions, including hypertension.11,12 This has been related to ventricular electrical instability, providing the necessary substrate for lethal ventricular arrhythmias.12,13 Greater QTd and left ventricular mass have been demonstrated in hypertensive individuals compared with normal individuals.11,13,14Considering the well-established, linear relationship between BP and the risk of cardiovascular events, the CV risk associated with PHT is intermediate between normotension and hypertension.2,03 Hence, electrocardiographic and echocardiographic indices of target-organ damage in PHT may also be intermediate between normotension and hypertension. The aims of this study were: (1) to compare the QTd and indices of left ventricular hypertrophy in adult black normal and prehypertensive subjects, and (2) to evaluate the relationship of QTd with electrocardiographic and echocardiographic indices in these subjects.     

Hypertensive retinopathy and its association with cardiovascular,renal and cerebrovascular morbidity in Congolese patients

Hypertension is a major public health problem worldwide and on the African continent.1,2 The disease, once considered to be rare outside Europe and North America, is now a leading cause of disability and mortality in developing countries. Its prevalence is projected to reach 30% worldwide by 2025.2Poor control of hypertension increases the likelihood of complications affecting the cardiovascular and cerebrovascular systems, kidney and retina, often labelled under the term target-organ damage (TOD).1 The development of subclinical TOD, such as left ventricular hypertrophy (LVH), increased intima–media thickness of the large vessels, microalbuminuria following glomerular dysfunction, cognitive decline and hypertensive retinopathy precedes the occurrence of major complications, which include stroke, congestive heart failure and myocardial infarction, renal failure and retinal vascular occlusions.3-5 In the Democratic Republic of Congo (DRC), the prevalence of systemic hypertension has been reported to be over 25%,6,7 whereas hypertension and associated complications account for over 20% of deaths among adults.8Studies have demonstrated that TOD increases cardiovascular risks over that already associated with elevated blood pressure alone. For example, it has been shown that once LVH has developed following long-standing systemic hypertension, it behaves as an independent risk factor and a predictor of both further cardiac complications,9 and other incident vascular events such as ischemic stroke and myocardial infarction.10 Similarly, the presence of cerebrovascular and renal damage may raise cardiovascular risk over that conferred by hypertension itself.11,12In addition, hypertensive retinopathy has long been known as a predictor of systemic morbidity and mortality. Both epidemiological and clinical studies have provided evidence that markers of hypertensive retinopathy are associated with raised blood pressure, systemic vascular diseases, and subclinical cerebrovascular and cardiovascular disease, and predict incident clinical stroke, congestive heart failure and mortality due to cardiovascular complications.13 This association of hypertensive retinopathy with other TOD has also been shown to be independent of blood pressure and other risk factors, which supports the recommendation that retinal vascular changes should be assessed in individuals with systemic hypertension for better extra-ocular TOD risk stratification.13While the number of reports on hypertensive TOD has been on the rise on the African continent, the relationship between hypertensive retinopathy and other TOD has largely remained unexplored. The aim of this study was to examine the association of hypertensive retinopathy with LVH, chronic kidney disease (CKD) and stroke in Congolese patients.     

Prevalence and risk factors for hypertension and association with ethnicity in Nigeria: results from a national survey

Hypertension is increasingly being recognised as an important public health problem in sub-Saharan Africa, with 26.9% of men and 28.4% of women in 2000 being estimated to have hypertension.1 Although lower than the prevalence in high-income countries (37.4% in men and 37.2% in women), in terms of numbers of people affected, the burden of hypertension in low- and middle-income countries is greater due to the large population.1Hypertension has been recognised as a strong independent risk factor for heart disease and stroke and a predictor of premature death and disability from cardiovascular complications.2 It has been reported that 13.5% of deaths and 6% of disability-adjusted life years (DALYs) were attributed to hypertension globally, and for low- and middle income people, these figures were 12.9 and 5.6%, respectively over the period 1990 to 2001.3 Although infectious diseases remain the leading cause of mortality and morbidity in sub-Saharan Africa, the prevalence of cardiovascular disease and hypertension is rising rapidly.4It has been emphasised that urbanisation is a key reason for the increasing rates of hypertension, as evidenced by the higher prevalence of hypertension in urban areas.4-6 Urban lifestyles, characterised by sedentary living, increased salt intake, obesity and stress contribute to these differences.5 With the urban population in sub-Saharan Africa projected to increase, a greater risk of hypertension is anticipated.Studies on the association between ethnicity and hypertension in high-income countries have documented a higher prevalence of hypertension in black ethnic groups compared to white ethnic groups.7-9 Reasons for this association are complex, unclear and much debated, reflecting genetic and biochemical mechanisms, and environmental and socio-economic factors.10,11 There is limited evidence regarding differences in the prevalence of hypertension between ethnic groups within the broader classification of black ethnicity.6,12,13Studies in Nigeria and sub-Saharan Africa have mainly involved specific geographical areas or have focused on sub-groups of the population.5,14 Surveys from Nigeria report prevalence estimates ranging from 20.2 to 36.6%, but all have involved participants with different age ranges.15-18 To plan services for hypertension in Nigeria, it is essential to have accurate prevalence estimates for the whole population and to identify populations at risk.Nigeria, which is the most populous country in sub-Saharan Africa, is home to over 250 different ethnic groups. Nigeria is experiencing rapid urbanisation of the population, which is likely to increase the population at risk for hypertension.19 The present study is one of the largest population-based surveys in the region and is able to provide a nationally representative estimate of hypertension for Nigeria.     

Diagnostic value of plasma C-type natriuretic peptide levels in determination of the duration of mesenteric ischaemia

Acute mesenteric ischaemia (AMI) causes significant morbidity and mortality if not promptly diagnosed and treated. If medical interventions are delayed, the patient may sustain serious ischaemic injury leading to bowel necrosis, so large segments of bowel may require surgical resection. Often these patients have poor clinical outcomes and suffer from complications such as malnutrition.1,2 Mesenteric ischaemia makes up 0.1% of all hospital admissions.1 Even though technological advances have been made in diagnostic laboratory and imaging techniques, AMI remains fatal in 60% of patients diagnosed with this condition.1,3Scientists have been investigating whether there are specific sensitive biomarkers that may indicate the presence of AMI.2,4 Several endothelial markers have been identified as putative biomarkers that may reveal the severity and duration over which mesenteric ischaemia has been sustained.5 However, markers that are effective enough for use in clinical practice have yet to be identified.Natriuretic peptides, namely atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and C-type natriuretic peptide (CNP) function in maintaining fluid and electrolyte balance as well as blood vessel tone. CNP is released by vascular endothelial cells, and this biomarker’s function in influencing vascular tone has been investigated.8,7 It has been hypothesised that CNP is an endothelium-derived hyperpolarising factor (EDHF) that specifically affects the degree of resistance in the mesenteric arteries.8 In this study, we aimed to investigate plasma CNP levels during early and advanced stages of mesenteric ischaemia so as to determine whether CNP levels are a good indicator of severity of AMI in a rat model.     

Can empirical hypertonic saline or sodium bicarbonate treatment prevent the development of cardiotoxicity during serious amitriptyline poisoning? Experimental research

Tricyclic antidepressant (TCA) drugs are commonly used to treat many neuropsychiatric diseases.1 Amitriptyline is the most commonly prescribed antidepressant, and it is a frequent cause of toxicity in drug overdoses. TCA overdose primarily affects the neurological, cardiovascular and respiratory systems.1,2Blockage of the rapid sodium channels is responsible for drug-induced cardiotoxicity, which clinically manifests as PR, QT and QRS prolongation, ventricular or supraventricular arrhythmias, hypotension and heart failure.1,3 Sodium bicarbonate (NaHCO₃) administration is the most widely accepted treatment to reduce amitriptyline-induced cardiotoxicity.2,4,5 However, at an alkaline pH, the volume distribution of amitriptyline expands, and the elimination time is longer. Therefore, NaHCO₃ treatment is suggested only in the presence of cardiac findings.6 Hypertonic saline (HS) administration has been shown to be useful, particularly when cardiotoxicity is accompanied by hypotension.7-9There is always a need for a medication to prevent cardiotoxicity that will save patients’ lives, especially when toxic doses have been ingested. Although studies have compared the efficacy of HS and NaHCO₃ treatments in patients with cardiotoxicity, the role of these therapies to prevent or reduce cardiotoxicity in patients who may potentially develop severe toxicity has not been investigated. The aim of this experimental study was to compare the effect of early administration of HS or NaHCO₃ on preventing cardiotoxicity in rats that had received toxic doses of amitriptyline.     

Prevalence of anaemia among patients with heart failure at the Brazzaville University Hospital

Heart failure (HF) is a frequent cause of hospitalisation in cardiology. Its prognosis depends on several factors, including anaemia, which is common among patients with heart failure.1 Anaemia is an independent prognostic factor for mortality in chronic HF and is associated with higher rates of mortality, hospitalisation and re-admission.2,3 Anaemia is a powerful independent predictor of death and hospitalisation in systolic and diastolic dysfunction.2,4-7In order to improve the management of patients suffering from systolic and diastolic HF, it is critical to understand the relationship between HF and anaemia, and the possible outcomes. The aim of this study was to determine the prevalence of anaemia in patients with heart failure and to evaluate its impact on the prognosis of patients in Brazzaville, Congo.     

Sickle cell trait is not associated with chronic kidney disease in adult Congolese patients: a clinic-based,cross-sectional study

Chronic kidney disease (CKD) and end-stage renal disease (ESRD) are associated with significant cardiovascular (CV) and renal morbidity and mortality rates, with substantial economic burden.1,2 Therefore, early identification of CKD patients at high risk of progression is urgently needed for early and targeted treatment to improve patient care.1-3 Diabetes and hypertension are the primary risk factors for CKD and ESRD but do not fully account for CKD and ESRD risk.1-3 Marked variability in the incidence of CKD suggests that factors other than diabetes and hypertension contribute to its aetiology.4Family studies have suggested a genetic component to the aetiology of CKD and ESRD.5 In African Americans, high-risk common variants in the Apol1/MYH9 locus may explain up to 70% of the differences in ESRD rates between European and African Americans.5 While this finding has great implications for ESRD, the identification of additional risk factors for CKD, including genetic loci in association with estimated glomerular filtration rate (eGFR), may help to advance our understanding of the underpinnings of CKD in African Americans.5 In this era of identifying genetic risk factors for kidney disease, it may be appropriate to revisit one of the most common genetic disorders: sickle cell haemoglobinopathies.5In this regard, sickle cell trait (SCT), present in approximately 7–9% of African Americans, has been reported to be a potential candidate gene.6 However, conflicting reports exist as to whether SCT is a risk factor for the progression of nephropathy.6,7 Haemoglobin S (HbS) was selected for in Africa because of the protection it affords from malarial infection, a scenario similar to the protection from trypanosomal infection provided by heterozygosity for APOL1 nephropathy risk variants.6Whereas APOL1 contributes to risk for nephropathy in an autosomal recessive inheritance pattern, HbS reportedly had a dominant effect on risk, with SCT being associated with ESRD.6 In line with this finding, a few small studies on African Americans reported HbS as an independent risk factor for CKD and ESRD.8 However, other studies using a large sample of African Americans stated that SCT was not independently associated with susceptibility to ESRD in African Americans,6 highlighting the need for further studies in other populations such as those of sub-Saharan Africa where SCT is prevalent.Although SCT is very prevalent in black Africans,9 few studies have been conducted to assess the association between SCT and CKD.10 In Democratic Republic of Congo (DRC), the prevalence of CKD and SCT has been reported to be 12% and 17–24%, respectively.11-13 No study has evaluated the frequency of SCT among CKD patients to assess its association with reduced kidney function. Therefore, the aim of this clinic-based, cross-sectional study was to assess the potential association between SCT and CKD among adult Congolese patients.     

Knowledge,attitude and behaviour regarding dietary salt intake among medical students in Angola

High salt (sodium chloride) consumption is an important determinant of high blood pressure and cardiovascular risk. According to World Health Organisation (WHO) statistics, over 80% of cardiovascular disease (CVD) deaths take place in low-and middle-income countries, and elevated blood pressure levels were a major cause of these CVD deaths in those countries.1 Lifestyle factors such as unhealthy diet, physical inactivity, tobacco use and harmful use of alcohol have been considered the most important behavioural risk factors for heart disease and stroke.2Among dietary factors, high salt intake has been the most strongly associated with raised blood pressure and increased risk of stroke and CVD.3 Therefore dietary sodium restriction has been recommended as a non-pharmacological approach to blood pressure lowering,4-6 and for the prevention and control of non-communicable diseases at the population level.7,8Cumulative evidence has shown that even a modest reduction in salt intake was associated with blood pressure lowering and therefore with a significant reduction in incidence of cardiovascular events.9-12 Furthermore, data from the most recent systematic review and meta-analyses has shown the benefit of lowering sodium intake in apparently healthy adults and children,13 and in both hypertensive and normotensive individuals, irrespective of gender and ethnic group.9Since hypertension is associated with CVD worldwide, a public health intervention to reduce high blood pressure must target the role of lifestyle, particularly reduced sodium intake.7 Therefore, several countries have initiated strategies to reduce dietary salt intake in the general population by a combination of various procedures such as public education, food labelling, and collaboration with the food industry to reduce the salt content of processed food.14Among sub-Saharan African countries, only Nigeria and South Africa have developed dietary guidelines regarding salt intake.15 Recently, the South African government implemented important specific legislation towards decreasing salt intake in the population by reducing sodium content of processed foods by industries.16 Therefore, the current public health recommendation is that countries should launch national initiatives to reduce the over-consumption of salt as part of non-communicable disease prevention and healthy nutrition policies for limiting salt intake to less than 5 g/day for the general population including children.7 Despite of this guideline, however, high sodium intake remains prevalent around the world, with average daily salt intake varying from 5 to 18 g/day per person.17Although processed foods have been found to be the principal source of excessive dietary salt intake,18 sources of dietary sodium vary largely worldwide and may be influenced by cultural context and dietary habits of the population.19 In sub-Saharan African countries experiencing demographic and epidemiological transition, the rapid rise in prevalence of CVD (chiefly hypertension) has been attributed to lifestyle change, including high dietary sodium intake.20,21 However, consistent data from studies on risk factors are lacking for the majority of these countries.With regard to Angola, available data from a cross-sectional study reported a high prevalence of multiple cardiovascular risk factors, such as hypertension, sedentary lifestyle, electrocardiographic left ventricular hypertrophy,22 and high rate of the metabolic syndrome23 in an apparently healthy middle-aged population of university public employees living in urban and peri-urban areas.Determining the level of sodium intake in the population is crucial to establish intervention strategies and policy on reduction of sodium intake. For medical students in particular, it is very important to assess their awareness regarding dietary salt intake, since they are the future providers of healthcare information for the counselling of people about the need to reduce salt consumption. The aim of this study was to determine salt intake and to assess the knowledge, attitude and behaviour regarding dietary salt among medical students.     

Cardiac surgery for patients with heart failure due to structural heart disease in Uganda: access to surgery and outcomes

Improvement in the control of infectious diseases and malnutrition associated with changes in lifestyle has led to a new epidemiological pattern in many low- and middle-income countries. Non-communicable diseases, mainly cardiovascular disorders, have emerged as major causes of morbidity and mortality in most sub-Saharan African countries.1 Hospital-based studies indicate that heart failure (HF) accounts for 3–7% of all admissions to African hospitals.2,3-7Although there has been increasing interest in the epidemiology of cardiovascular diseases in the African continent,7-9 recent data from Uganda are scarce7,10 but most needed to guide public health policies. Most registers originate from South Africa and cannot be transposed to poorer sub-Saharan countries.2,11Echocardiography is a mainstay in the assessment of HF. Unfortunately, access to echocardiography remains limited in many African countries due to cost and lack of skilled health workers, thereby leading to little data on cardiovascular diseases.12We report on the distinctive patterns of HF through a prospective, cross-sectional, hospital-based study in patients referred for suspected heart disease in urban Kampala, Uganda, in order to characterise the features of HF and to tailor future interventions. We also aimed at assessing access to invasive interventions and outcomes in patients with surgical indications.     

Undiagnosed myopathy before surgery and safe anaesthesia table

Patients with muscle pathology are a challenge for anaesthesiologists because of possible life-threatening general anaesthesia complications. A review of the current medical literature on the issue clearly indicates that increasing awareness by anaesthesiologists in recent years has led to a reduction in the occurrence of adverse events in patients with diagnostically well-defined muscle disease. On the other hand, the current emerging aspect is that the great majority of complications concern subjects with clinically non-overt (silent to mildly symptomatic) and thus undiagnosed myopathy. With a view to improving prevention of possible critical anaesthesia complications in such patients, we present a "Safe Anaesthesia Table", listing both the anaesthetic drugs to be avoided and those considered harmless for myopathic patients, irrespective of age and type of pathology. In addition, a brief outline about the clinical aspects suggestive of a possible muscle pathology is also provided. Using "safe drugs" during routine surgical procedures in subjects with suspected undiagnosed myopathy will enable the anaesthesiologist to avoid delaying surgery, while protecting them from anaesthesia complications. By following this approach the presumed myopathy can be properly investigated after surgery.Key words: anaesthesia complications, undiagnosed myopathy, safe anaesthesia, hyperCKemiaPatients suffering from a variety of Muscle Diseases can experience critical adverse events during and after general anaesthesia. Usually these complications are triggered by volatile anaesthetics or succinylcholine. In some myopathic patients, however, life-threatening side effects may also be precipitated by other agents, namely anticholinesterase and neuroleptic drugs (1-6). All complications can be unpredictably combined and present with different clinical severity. As described in a systematic review by DeVries et al. (7), side effects of anaesthetic drugs currently represent 2% of all in-hospital untoward episodes, the decrease being mainly due to extensive use of total intravenous anaesthesia and reduced administration of succinylcholine (1-4). Nonetheless, in view of the possible fatal outcome, they remain a major concern for anaesthesiologists.Acute rhabdomyolysis with the resultant myoglobinuria is among the most severe anaesthesia-related complications for children and adults with muscle pathology. The syndrome may occur alone or as the culmination of a typical episode of Malignant Hyperthermia (MH). Susceptibility to this life-threatening syndrome is an uncommon pharmacogenetic muscle disorder characterized by altered calcium release from the sarcoplasmic reticulum. Besides rhabdomyolysis and myoglobinuria, the complete clinical manifestation of an MH event includes muscle rigidity, high body temperature, metabolic acidosis, hyperkalaemia, and cardiac arrhythmia. Notably, apart from anaesthesia-related MH episodes, susceptible subjects are basically asymptomatic, even though about half of them present raised serum CK (3, 4, 8). Succinylcholine and volatile anaesthetics may trigger a typical MH crisis also in patients with other genetic disorders, as Central Core Disease, a rare congenital myopathy allelic to MH Susceptibility (2, 3, 5). Acute rhabdomyolysis with myoglobinuria mimicking an MH episode, albeit incompletely, is more frequently described in patients with muscular dystrophy and usually referred to as an MH-like episode (1, 2, 9). These episodes are often complicated by hyperkalaemia and severe cardiac arrhythmia, clinical events that have also been reported for other muscle pathologies, as metabolic muscle disorders, congenital myopathies and channelopathies (3, 10-18).Cardiac and respiratory complications are highly critical side effects potentially experienced by myopathic patients, both during and after general anaesthesia. Their occurrence is directly linked to the frequency of underlying ventilatory muscle pathology and cardiac involvement present in muscular dystrophies and related disorders. Volatile anaesthetics may determine heart complications through a calcium-related cardiodepressive effect and a complex dysrhythmic action. Succinylcholine and other depolarizing agents can induce hyperkalaemia followed by fatal ventricular arrhythmia. Serum potassium may also be increased by anticholinesterase drugs (1, 2, 19).Other critical side effects of anaesthetic agents are characterized by myotonic reactions, muscle spasms and localized or generalized rigidity (1-6). Myotonia and related clinical manifestations are usually caused by depolarizing muscle relaxants, but can also be determined by anticholinesterase drugs (1-4, 18). The latter can also enhance vagal responses that aggravate possible autonomic dysregulation. Myotonic reactions induced by succinylcholine or anticholinesterase drugs are often localized to the masseter muscles, but exacerbation may lead to life-threatening respiratory muscle involvement (18). Jaw muscle stiffness may also result from prolonged masseter contraction without electrical activity (spasm): this sign has to be carefully evaluated because possible onset of generalized rigidity, culminating in an MH episode (1-5). Widespread muscle rigidity, associated with central nervous system-induced hyperthermia, can be determined by neuroleptic drugs (butyrophenones and phenothiazines). Accordingly these substances are currently mostly replaced by propofol and opioids (1-4).There are no available population studies on the prevalence of anaesthesia complications in myopathic subjects. Nonetheless, the extent of the problem is illustrated by recent observations on overall prevalence of genetic myopathies, indicating an index of about 1 case per 2,500 inhabitants (20). This estimate is higher than previous data reviewed by Emery in 1991 (21), likely because of the prolonged life expectancy of myopathic patients, e.g. those with Duchenne Muscular Dystrophy (DMD), and because the clinical diagnosis of pauci- or mildly symptomatic patients has been facilitated by the widespread use of DNA molecular analysis.Nowadays in Italy, as in other Western countries, patients with overt myopathy are usually admitted to surgery with a precise diagnosis. Consequently, thanks to specific preventive measures diffusely adopted by anaesthesiologists, potential anaesthesia-associated side effects seem on the whole to have decreased (2-4, 6, 9, 13, 22-26). On the other hand, analysis of recent reports (5, 6, 11, 15, 17, 25, 27) indicates that complications in patients with undiagnosed myopathy are the emerging aspect of the issue, with particular evidence in the extensive review published by Gurnaney et al. (25) on intra- or post-operative rhabdomyolisis, cardiac arrest and hyperkalaemia in myopathic patients. By examination of 173 references, the Authors focused two remarkable points: 1) the great majority of complications involved subjects with undiagnosed myopathy; 2) nearly all the observations concerned patients with DMD or other dystrophinopathy. They were predominantly pauci- or very mildly symptomatic patients, in whom myopathy had been simply overlooked, and the eventual diagnosis of muscular dystrophy pursued on account of the adverse reaction to anaesthesia. Such a high overall level of undiagnosed myopathy was unexpected. A similar observation, that easily escaped general attention because published in a German- language journal, was also previously reported by Breucking et al. (26). Said investigation on 221 patients with DMD or another dystrophinopathy found that severe anaesthesia-related side effects occurred only in children or adolescents with undiagnosed dystrophinopathy.Minimal to mild symptoms of myopathy may also characterize the clinical phenotype of manifesting carriers of dystrophinopathy or other muscular dystrophy, as calpainopathy or dysferlinopathy (28-30). Due to non-overt symptomatology, these carriers could hypothetically go unrecognized at admission to surgery, with the high-risk of anaesthetic complications similar to those in patients with undiagnosed myopathy. This inference has been confirmed by recent literature which indicates at least two cases of anaesthesia-related critical events in carriers of dystrophinopathy (31, 32). To our knowledge , similar data have not yet been reported for other muscular dystrophies.On the whole, currently available data on muscle disease and related anaesthesia complications suggest that the patients involved are mostly those with Clinicallyunclear, because silent or pauci- to mildly symptomatic, Undiagnosed Myopathy (CU Myopathy). With a view to improving prevention of possible critical anaesthesia complications in such patients, we present a list of anaesthetic drugs considered harmless to them ("Safe Anaesthesia Table"). Essential indications are also provided on clinical aspects suggestive of myopathy.     

Analysis of clinical outcomes of intra-aortic balloon pump during coronary artery bypass surgery

An intra-aortic balloon pump (IABP) increases coronary blood flow and reduces left ventricular afterload.1-3 It helps to increase the necessary amount of time for heart recovery in low cardiac output syndrome following a cardiopulmonary bypass (CPB) or ischaemic events. In earlier reports, researchers had suggested that postoperative heart failure was the single indication for IABP support.1,2 However, these indications have widened, and the use of IABP support has recently become more common.Frequently reported complications of IABP include bleeding, aorto-iliac injury and thrombocytopenia.4,5 In-hospital mortality and early mortality of patients requiring IABP support is high, ranging from 26 to 50%, due to the cardiac problems that initially led to the need for this support.6,7The elderly population is continuously increasing across the globe. Parallel with this increase, the number of older patients being referred for coronary artery bypass grafting (CABG) has also increased.8 Although several studies have shown a significant increase in surgical mortality of elderly patients,9 there have been no studies regarding clinical outcomes of IABP in elderly patients.In the present study, we aimed to analyse and compare older with younger patients, regarding clinical features, postoperative complications, intensive care unit and hospital stays, and morbidity and mortality rates in patients who had undergone CABG surgery and required IABP support.     

Ambulatory blood pressure profiles in a subset of HIV-positive patients pre and post antiretroviral therapy

South Africa has 5.6 million people living with HIV/AIDS and has the largest antiretroviral therapy (ART) programme globally, with more than two million people accessing ART.1 Although ART has significantly decreased the mortality rate from HIV infection, these individuals are now living longer and are at risk of developing metabolic (dyslipidaemia, lipodystrophy, dysglycaemia), cardiovascular and renal complications from ART and chronic exposure to HIV infection.2-7Chronic HIV and ART are associated with increased risk of developing hypertension.8 In studies of HIV-positive patients in high-income countries, hypertension prevalence ranges from 13 to 34%.9,10 However, data from low- and middle-income countries remain sparse.Nocturnal blood pressure (BP) is superior to daytime or office BP as a predictor of cardiovascular disease.11 Non-dipping is defined as an abnormal diurnal rhythm manifested by a blunted nocturnal decline in systolic BP (SBP).11 It is associated with more severe hypertensive target-organ damage (left ventricular hypertrophy, microalbuminuria and cerebrovascular disease) and is also a predictor of increased cardiovascular risk, both in hypertensive and normotensive populations.11Studies from high-income countries have shown an increased prevalence of non-dipping with HIV infection.9,12 However, the participants in these studies were largely white, middle-aged males. Since the majority of subjects with HIV infection in sub-Saharan Africa are young black females, it is not known whether the same relationship between dipping status and HIV infection would be found. In addition, there are data showing that black HIV-negative individuals have less nocturnal dipping compared to their white counterparts.5,13,14Therefore, the aims of this study were to document the prevalence of chronic kidney disease (CKD) and hypertension at baseline (ART naïve) in a healthy HIV-positive cohort, and to assess changes in these parameters after six months on ART. The characteristics of ambulatory blood pressure (ABP) in a subset of patients were to be recorded and compared to a control group of HIV-negative patients.     

Comparison of one- and two-stage basilic vein transposition for arterio-venous fistula formation in haemodialysis patients: preliminary results

In recent years, the number of patients requiring haemodialysis (HD) has been rapidly increasing globally, including Turkey. Arterio-venous fistula (AVF) is the most frequently used method in patients with end-stage renal failure (ESRF) for HD.1The Kidney Disease Outcome Quality Initiative (KDOQI) recommends autologous radio-cephalic or brachio-cephalic AVF as a primary method of choice in HD patients, and basilic vein transposition (BVT) as a secondary option.2,3 In 1976, Dagher et al.4 first described the technique of BVT for HD. In later years, several techniques were used.5-11 This study aimed to compare the patency and complication rates of AVF formed by one-stage and two-stage BVT.     

Is the relationship of body mass index to severity of coronary artery disease different from that of waist-to- hip ratio and severity of coronary artery disease? Paradoxical findings

Although obesity has been regarded as an independent risk factor for coronary artery disease (CAD) by the American Heart Association (AHA) and investigators of the Framingham Heart study in the 1980s and 1990s,1-3 this has not been supported by recent clinical trials. Moreover, the positive linear relationships between obesity and CAD, as reported by some studies, were as a result of univariate analysis of their data. However, by using multivariate analysis of these study data, which included other cardiovascular risk factors such as diabetes mellitus (DM), hypertension (HTN) and hyperlipidaemia, this relationship was shown to be dramatically reduced.4,5In the Munster Heart study (PROCAM) and similar studies, the positive relationship between body mass index (BMI) and cardiovascular risk factors, with cardiac mortality, which attributed obesity as an independent risk factor, appeared to be due to the associated cardiovascular risk factors that usually accompany obesity.6-10 In these studies there was also a strong positive correlation between high BMI and other cardiovascular risk factors.However, findings of recent studies in this regard were opposite to those of previous studies. According to their findings, not only was obesity not a risk factor for CAD but it also had a protective effect on the progression of CAD, which is known as the ‘obesity paradox’.11,12 On the other hand, abdominal adiposity has always been associated with increased cardiovascular disease and mortality rate, independent of patients’ weight.13,14This study was designed to evaluate not only the impact of BMI but also waist-to-hip ratio (WHR) on the severity of CAD, based on angiographic findings.     

The proposed role of plasma NT pro-brain natriuretic peptide in assessing cardiac remodelling in hypertensive African subjects

Left ventricular hypertrophy (LVH) represents an important index of pre-clinical disease, and carries incremental prognostic value beyond that afforded by traditional coronary risk factors.1 In a large cohort of black persons, LVH proved to be an even more powerful predictor of mortality than coronary artery disease and left ventricular ejection fraction (LVEF).2 Hence early detection of LVH is very important in the management of the hypertensive patient.Electrocardiography can be very useful in assessing LVH, especially in middle- and low-income countries, because it is relatively cheap, accessible and not much expertise is required to operate an electrocardiography machine. Electrocardiographic criteria for LVH are, however, not very sensitive, while the alternative more accurate method of echocardiography is uneconomical, especially in resource-limited countries.3 Besides requiring more expertise, the results may not be adequate in all patients, especially in those with obesity or pulmonary disease.4 This situation has led to research on the use of biomarkers such as NT-proBNP and BNP in the detection of the presence of LVH and monitoring its regression.5B-type natriuretic peptide is a cardiac neurohormone secreted by myocardial cells located on both the atria and ventricles, mainly by LV myocardial cells in response to volume expansion and pressure overload.6,7 Plasma BNP and NT-proBNP levels are a useful marker of LVH in hypertension, and have also been found to rise progressively with increasing severity of hypertension, particularly when ventricular hypertrophy is present.6 Similarly, plasma BNP and NT-proBNP levels are useful to discriminate between patients with regard to cardiac remodelling and could be considered as a screening tool to select hypertensive patients eligible for transthoracic echocardiography.5 NT-proBNP is also a useful biomarker in differentiating hypertensive subjects with LVH from those with heart failure.8,9Most of the current knowledge and published data on the use of plasma NT-proBNP in hypertensive LVH and hypertensive heart failure (HHF) are based on studies in Europe and the United States of America, with a dearth of data in black Africans in whom the burden of hypertension and hypertensive heart disease is very high.10,11 For example, the THESUS study, which studied 1 006 acute heart-failure subjects in nine sub-Saharan African countries, inclusive of Nigeria, showed that hypertension was the commonest cause of heart failure, accounting for heart failure in 45.4% of cases.12 In addition, most previous studies on this subject never considered LV diastolic function or RV function, both of which are reported to be prognostic markers in hypertensive heart failure.13,14 We therefore decided to examine the relationship between circulating NT-proBNP and left and right ventricular remodelling in a black African hypertensive cohort.     

Epidemiological African day for evaluation of patients at risk of venous thrombosis in acute hospital care settings

Acute venous thromboembolism (VTE) is a complication in patients hospitalised for a wide variety of acute medical and surgical conditions.1,2 In developed countries, VTE is the most common preventable cause of death among hospitalised patients. Over the last 30 years, extensive research has demonstrated a high risk of VTE in patients who undergo major surgery or experience severe trauma. Patients hospitalised for acute medical illness have approximately the same level of VTE risk as patients who undergo major general surgery.3-5The benefits of VTE prophylaxis are similar for both medical and moderate-risk surgical patients.6,7 VTE prophylaxis is substantially underused. There is great variation in the use of prophylaxis between countries. Even when prophylaxis is used, it may be used sub-optimally.8-10 Although some surveys and studies suggest that physicians have begun to recognise VTE as a serious health problem and use prophylaxis for at least some high-risk patients, a number of recent studies demonstrate that VTE prophylaxis remains underutilised.11-20     

An echocardiographic study of infective endocarditis,with special reference to patients with HIV

Important developments during the last 20 years have facilitated rapid and accurate diagnosis of infective endocarditis (IE), and recent guidelines emphasise the role of early surgical treatment when complications supervene.1,2 The emergence of prosthetic valve endocarditis, catheter-related endocarditis, and an increased incidence of antibiotic resistance has led to new challenges for the physician.3 From a microbiological standpoint, the rise in staphylococcal infections, and the immune paresis associated with HIV infection pose further diagnostic challenges that also have important implications for management.3Bacteraemia is said to be common in HIV-positive patients, due to the numerous immunological defects present in this disease.4 Furthermore, in the setting of HIV exposure and altered immunity, infection is not uncommonly caused by unusual organisms, such as barbonella, salmonella, and listeria.1 This raises the question as to whether IE presents a somewhat different clinical and echocardiographic picture in the HIV-positive patient.It is known that the degree of immunosuppression, manifested by a reduced CD₄ lymphocyte count, strongly correlates with the presence of echocardiographic abnormalities.5 Whether the immunosuppression associated with HIV may alter the clinical picture of valvular heart disease, particularly IE, is not clear. Since a decrease in CD₄ count is thought to predispose to HIV-associated cardiac disease, this study was designed to determine the pattern of cardiac involvement in the HIV-infected subjects who develop IE.5,6     

Decline in mean platelet volume in patients with patent foramen ovale undergoing percutaneous closure

Patent foramen ovale (PFO) is a haemodynamically insignificant communication that is present in 24% of the general population.1 In 1988 Lechat et al. performed transthoracic echocardiography (TTE) with contrast injection and showed that patients with stroke of unknown cause had PFOs more frequently than the controls.2 Since then, many studies have confirmed this association. In 2000, a meta-analysis summarised the evidence that PFO was more likely to be found in stroke patients than in stroke-free individuals.3In about 50 to 60% of patients younger than 55 years, the cause of acute ischaemic stroke remains undefined.4 In this group, interatrial septal abnormalities are found in 55 to 60% of cases, which is higher than in the normal population.In another meta-analysis, Mattle et al. reported a higher prevelance of PFO in patients with cryptogenic stroke than in patients with a stroke of known causes.1 The postulated possible mechanisms underlying the stroke in the presence of PFO are: paradoxycal embolism, thrombus formation within the conduit of the PFO, or susceptibility of patients with PFO to atrial arrhythmias with possible intra-atrial thrombus formation.4-8Although paradoxycal embolism, which is associated with deep-vein thrombosis (DVT), is the favoured hypothesis, DVT in patients with PFO is usually undetectable.9 Therefore, increased platelet activity as well as disorders in the coagulation cascade may contribute to the association between PFO and stroke.Mean platelet volume (MPV) is a measure of platelet size and is a potential marker of platelet reactivity. It has been shown that larger platelets are metabolically and enzymatically more active and have greater prothombotic potential.10,11The aim of this study was (1) to compare MPVs of PFO patients with and without a history of cryptogenic stroke, and (2) to determine the effect of percutaneous PFO closure on MPV.     

Postoperative atrial fibrillation in patients with left atrial myxoma

Paroxysmal atrial fibrillation (AF) is the most common arrhythmia following cardiac surgery such as coronary artery bypass grafting (CABG), and often occurs between the second and fourth postoperative days.1,2 The reported incidence of paroxysmal AF after CABG surgery varies widely, from five to 40%, which is lower than in cases of valvular cardiac surgery.3,4 Although this arrhythmia is usually benign and self-limiting, it may also be associated with increased risk of embolic events, haemodynamic instability, haemorrhagic complications, prolonged hospital stay and higher rates of re-admissions, increasing the healthcare costs.5-7Several risk factors have been proposed for paroxysmal AF after CABG or valvular cardiac surgery, such as advanced age, genetic predisposition, chronic obstructive pulmonary disease, heart failure or increased peri-operative ischaemia.8-10 In addition, certain echocardiographic parameters such as left atrial (LA) diameter or left ventricular (LV) function, and electrocardiographic parameters including P-wave duration and P-wave dispersion (Pd) have been shown to be associated with postoperative AF.11-13Although postoperative AF and its predictors after CABG and valvular surgery have been well researched, no study has been performed to explore the incidence or predictors of postoperative AF in patients with LA myxoma. The aim of this study was to identify the prevalence and predictors of postoperative AF in a pure cohort of patients with LA myxoma.