Enhanced dispersion of atrial refractoriness as an electrophysiological substrate for vulnerability to atrial fibrillation in patients with paroxysmal atrial fibrillation.

Atrial electrical remodeling plays a part in recurrence of atrial fibrillation (AF). It has been related to an increase in heterogeneity of atrial refractoriness that facilitates the occurrence of multiple reentry wavelets and vulnerability to AF. AIM: To examine the relationship between dispersion of atrial refractoriness (Disp_A) and vulnerability to AF induction (A_Vuln) in patients with clinical paroxysmal AF (PAF). METHODS: Thirty-six patients (22 male; age 55+/-13 years) with > or =1 year of history of PAF (no underlying structural heart disease--n=20, systemic hypertension--n=14, mitral valve prolapse--n=1, surgically corrected pulmonary stenosis--n=1), underwent electrophysiological study (EPS) while off medication. The atrial effective refractory period (AERP) was assessed at five different sites--high (HRA) and low (LRA) lateral right atrium, high interatrial septum (IAS), proximal (pCS) and distal (dCS) coronary sinus--during a cycle length of 600 ms. AERP was taken as the longest S1-S2 interval that failed to initiate a propagation response. Disp_A was calculated as the difference between the longest and shortest AERP. A_Vuln was defined as the ability to induce AF with 1-2 extrastimuli or with incremental atrial pacing (600-300 ms) from the HRA or dCS. The EPS included analysis of focal electrical activity based on the presence of supraventricular ectopic beats (spontaneous or with provocative maneuvers). The patients were divided into group A--AF inducible (n=25) and group B--AF not inducible (n=11). Disp_A was analyzed to determine any association with A_Vuln. Disp_A and A_Vuln were also examined in those patients with documented repetitive focal activity. Logistic regression was used to determine any association of the following variables with A_Vuln: age, systemic hypertension, left ventricular hypertrophy, left atrial size, left ventricular function, duration of PAF, documented atrial flutter/tachycardia and Disp_A. RESULTS: There were no significant differences between the groups with regard to clinical characteristics and echocardiographic data. AF was inducible in 71% of the patients and noninducible in 29%. Group A had greater Disp_A compared to group B (105+/-78 ms vs. 49+/-20 ms; p=0.01). Disp_A was >40 ms in 50% of the patients without A_Vuln and in 91% of those with A_Vuln (p=0.05). Focal activity was demonstrated in 14 cases (39%), 57% of them with A_Vuln. Disp_A was 56+/-23 ms in this group and 92+/-78 ms in the others (p=0.07). Using logistic regression, the only predictor of A_Vuln was Disp_A (p=0.05). CONCLUSION: In patients with paroxysmal AF, Disp_A is a major determinant of A_Vuln. Nevertheless, the degree of nonuniformity of AERP appears to be less important as an electrophysiological substrate for AF due to focal activation.     

Linking the Disabilities of Arm, Shoulder, and Hand to the International Classification of Functioning, Disability, and Health.

The objective of this study was to explore whether the items from a specific outcome measure, that is, Disabilities of the Arm, Shoulder, and Hand (DASH), for quantifying limb symptoms and functions in musculoskeletal disorders fit into the framework of the International Classification of Functioning, Disability and Health (ICF). All DASH items were compared to the ICF according to eight linking rules. Two groups of researchers performed the linking independently, and the results were compared by correlation. The 30 DASH items and four items from the optional modules were linked to 63 ICF categories and 11 chapters: 15 categories belong to the ICF body functions component and 48 to the activities and participation component. There were no items coded under the components body structure or environmental factors. Kappa index showed an agreement of 0.73 (p<0.001). The results showed that the content of the DASH does link well with the ICF framework. Clinicians and researchers must attend to the fact that certain domains and categories from the ICF are not covered by the DASH. Limitations of the instrument may be overcome by simultaneously using other instruments that address the intended content.     

Estimation of salt intake by urinary sodium excretion in a Portuguese adult population and its relationship to arterial stiffness.

BACKGROUND: Portugal has one of the highest mortality rates from stroke, a high prevalence of hypertension and probably a high salt intake level. AIM: To evaluate Portuguese salt intake levels and their relationship to blood pressure and arterial stiffness in a sample of four different adult populations living in northern Portugal. METHODS: A cross-sectional study evaluating 24-hour urinary excretion of sodium (24 h UNa+), potassium and creatinine, blood pressure (BP), and pulse wave velocity (PWV) as an index of aortic stiffness in adult populations of sustained hypertensives (HT), relatives of patients with previous stroke (Fam), university students (US) and factory workers (FW), in the context of their usual dietary habits. RESULTS: We evaluated a total of 426 subjects, mean age 50 +/- 22 years, 56% female, BMI 27.9+/-5.1, BP 159/92 mmHg, PWV 10.4+/-2.2 m/s, who showed mean 24h UNa+ of 202 +/- 64 mmol/d, corresponding to a daily salt intake of 12.3 g (ranging from 5.2 to 24.8). The four groups were: HT: n = 245, 49 +/- 18 years, 92% of those selected, 69% treated, BP 163/94 mmHg, PWV 11.9 m/s, 24 h UNa+ 212 mmol/d, i.e. 12.4 g/d of salt); Fam: n = 38, 64 +/- 20 years, 57 % of those selected, BP 144/88 mmHg, PWV 10.5 m/s, 24 h UNa+ 194 mmol/d, i.e. 11.1 g/d of salt; US: n = 82, 22 +/- 3 years, 57% of those selected, BP 124/77 mmHg, PWV 8.7 m/s, 24h UNa+ 199 mmol/d, i.e. 11.3 g/d of salt; FW: n = 61, 39 9 years, 47% of those selected, BP 129/79 mmHg, PWV 9.5 m/s, 24 h UNa+ 221 mmol/d, i.e. 12.9 g/d of salt. The ratio of urinary sodium/potassium excretion (1.9 (0.4) was significantly higher in HT than the other three groups. In the 426 subjects, 24h UNa+ correlated significantly (p < 0.01) with systolic BP (r = 0.209) and with PWV (r=0.256) after adjustment for age and BP. Multivariate analysis showed that BP, age and 24h UNa+ correlated independently with PWV taken as a dependent variable. CONCLUSIONS: Four different Portuguese populations showed similarly high mean daily salt intake levels, almost double those recommended by the WHO. Overall, high urinary sodium excretion correlated consistently with high BP levels and appeared to be an independent determining factor of arterial stiffness. These findings suggest that Portugal in general has a high salt intake diet, and urgent measures are required to restrict salt consumption in order to prevent and treat hypertensive disease and to reduce overall cardiovascular risk and events.     

Management of older patients presenting after a fall--an accident and emergency department audit.

BACKGROUND: It is common for older patients to present to accident and emergency (AE) departments after a fall. Management should include assessment and treatment of the injuries and assessment and correction of underlying risk factors in order to prevent recurrent falls. OBJECTIVES: To determine management of older patients presenting after a fall to the AE department of Groote Schuur Hospital in Cape Town, South Africa. METHOD: Hospital records were reviewed for a random sample of 100 patients aged 65 years and older presenting to the AE department after a fall, between December 2001 and May 2002. RESULTS: The mean age of the sample was 78.6 years (range 65-98 years); 72% of subjects were female. History of a previous fall, and history of drug or alcohol intake, were recorded in less than 20% of cases. Blood pressure and pulse rate were recorded in approximately 90% of cases, and pulse rhythm and postural blood pressure in 2%. Examination of the musculoskeletal system was done in 86% of cases and that of other systems in less than 50%; cognitive assessment was conducted in less than 30%. Radiological investigations were performed in 89% of cases, glucose and haemoglobin in 32%, renal profile and electrocardiogram in 5%, and urinalysis in 4%. Three-quarters of the patients were referred for further management: 52% to orthopaedic surgery, 12% to other surgical subspecialties, 6% to the general medical department, and 6% to other hospitals and clinics. No referrals were made to geriatric medicine, physiotherapy or occupational therapy. CONCLUSIONS: In managing elderly patients after a fall, the AE department focused on injuries sustained. Little effort was made to establish and manage risk factors, hence to prevent recurrent falls. Guidelines are needed for the management of such patients in AE departments.     

Hereditary protein C deficiency and portal-vein thrombosis

Inherited defects of the natural coagulation inhibitors predispose patients to thrombosis. These disorders have similar clinical presentations with a strong family history of thrombosis, episodes of recurrent venous thromboembolism, beginning in early adulthood. We report a case of upper gastrointestinal bleeding in a patient with portal hypertension due to portal-vein thrombosis secondary to hereditary protein C deficiency, an association that has seldom been reported.     

Intermittent etidronate partially prevents bone loss in hirsute hyperandrogenic women treated with GnRH agonist

Treatment with gonadotropin-releasing hormone (GnRH) agonist leads to enhanced bone turnover and accelerated bone loss in premenopausal women with endometriosis, uterine leiomyomatomas and hirsutism. Sodium etidronate is a powerful inhibitor of bone resorption which has been proven efficacious in the prevention and treatment of postmenopausal osteoporosis. The objective of this study was to evaluate the skeletal effects of 6 months of therapy with the depot preparation of the GnRH agonist triptorelin (decapeptil 3.75 mg intramuscularly every 4 weeks) in 24 hirsute patients, aged 24–33 years, with hyperandrogenic chronic anovulation. Ten patients also received cyclical etidronate in an oral dose of 400 mg/day for 2 weeks, followed by an 11-week period of 500 mg/day elemental oral calcium (one cycle). The remaining 14 patients received 500 mg/day of elemental calcium continuously. After 6 months all treatments were discontinued for at least a further 6 months. Bone mineral density (BMD) at lumbar spine and hip (dual-energy X-ray absorptiometry, Sophos LXRA, France) and biochemical markers (serum alkaline phosphatase, osteocalcin, urinary N-telopeptide and hydroxyproline/creatinine ratio) were evaluated at baseline, 6 months and 12 months. In the group given GnRH agonist alone BMD fell significantly at all measured skeletal sites during the first 6 months. In the patients treated with etidronate a significant decrease in BMD was observed at lumbar spine but not in the femoral neck and trochanter, and the changes at lumbar spine and trochanter were significantly smaller than those in the control group. At 6 months bone turnover was also increased in patients treated with GnRH and calcium. Cyclical etidronate prevented the increase in biochemical markers of bone formation and resorption, with the exception of calcium/creatinine excretion, which was significantly increased in both groups. Six months after treatment withdrawal BMD did not recover in either group. Biochemical markers (N-telopeptide, serum alkaline phosphatase) remained increased in those patients previously treated with calcium alone while they remained close to baseline values in the patients treated with cyclical etidronate.Our study indicates that: (1) GnRH agonist therapy causes remarkable bone loss in young individuals with androgen excess who are expected to have increased bone mass; (2) this bone loss can be partially prevented by intermittent cyclical etidronate therapy.     

Detection of HIV1 proviral DNA by PCR and hybridization with digoxigenin labelled probes.

One of the main obstacles for the introduction of PCR method to identify HIV1 proviral DNA in routine diagnostic laboratories is the use of radiolabelled oligodeoxynucleotide probes. Nonradioactive labelled probes have several advantages over radioactive labelling: they are stable for over 1 year, they can be produced easily in large amounts and they are safe. Polymerase chain reaction is an efficient and simple method to produce vector free inserts to use as probes. In this paper we describe a procedure for labelling DNA probes with digoxigenin-11-dUTP using the polymerase chain reaction. This non-radioactive labelling system was applied to detect HIV proviral sequences, amplified in vitro by PCR, from peripheral blood mononuclear cells DNA of infected subjects. We found identical sensitivities and specificities for probes synthesized with the non-radioactive and radioactive labelling procedures. The digoxigenin-11-dUTP can be efficiently incorporated during amplification of a DNA fragment using the polymerase chain reaction. This labelling and detection method proved to be specific, sensible and simple enough to be used in routine diagnostic laboratories for the detection of HIV1 infected individuals.