Endothelin system and atrial fibrillation post-cardiac surgery

Objective We investigated the relation between the endothelin system and atrial fibrillation. Background Endothelin has been implicated in the pathophysiology of atrial fibrillation, but the exact role of A- and B-receptors is unknown. Methods We obtained right atrial biopsies from patients in sinus rhythm and preserved left ventricular function, undergoing off-pump coronary artery bypass grafting. The expression of endothelin, A- and B-receptors was measured using real time reverse-transcribed polymerase chain reaction. Results We studied 52 patients (45 male, mean age 66 ± 1 years, mean ejection fraction 52 ± 1%). During a 5-day post-operative period, persistent atrial fibrillation occurred in 15 patients (28.8%). Endothelin mRNA expression was comparable in patients who subsequently developed atrial fibrillation and in those maintaining sinus rhythm. However, the former group displayed down-regulation of endothelin A- (by approximately 60%, p = 0.0059) and of B-receptors (by approximately 40%, p = 0.0084). The decreased endothelin A-receptor expression could predict atrial fibrillation occurrence (Wilks λ = 0.86, F = 6.16, p = 0.017). Conclusion Decreased endothelin A- and B-receptor expression is associated with atrial fibrillation after bypass surgery. Theofilos M. Kolettis and Zenon S. Kyriakides contributed equally to the study.     

Comparison of phalangeal ultrasound and dual energy X-ray absorptiometry in healthy male and female adolescents

The aims of this study were to determine if there is a correlation between dual energy X-ray absorptiometry (DXA) and phalangeal quantitative ultrasound (QUS) in identifying children and adolescents with low bone density, and to assess if body size influences the results of the two techniques to the same degree. Measurements were performed in 67 girls and 83 boys aged 14 to 19 y using DBM Sonic 1200 (IGEA, Carpi, Italy) and the DXA equipment (LUNAR Radiation Corp., Madison, WI, USA). Twelve adolescents (eight males and four females) reported a past history of nonosteoporotic fractures. Lumbar spine bone mineral density (LS BMD), total body bone mineral density (TB BMD) and total body bone mineral content (TB BMC) correlated positively with age, height, BMI and weight, in both genders. Amplitude-dependent speed of sound (Ad-SOS) was positively correlated with age, height and Tanner stages in both genders and negatively correlated with BMI in females. TB BMD, TB BMC and LS BMD positively correlated with Ad-SOS only in males. In females, there were no significant correlations between Ad-SOS, TB BMD, TB BMC and LS BMD measurements. Twelve teenagers with previous fractures (high impact fractures) were found to have lower DXA and QUS values than age-matched teenagers without fractures but the statistical significance was found only in relation to TB BMD values (p = 0.02). In conclusion, we obtained results similar to those that have been reported by other authors using different QUS techniques. Furthermore, the Ad-SOS measurements taken at the distal metaphysis of the proximal phalanges correlate poorly with LS BMD and TB BMD measured by DXA in growing subjects. (E-mail: zhalaba@poczta.onet.pl)     

Endothelin-B receptors and ventricular arrhythmogenesis in the rat model of acute myocardial infarction

The arrhythmogenic effects of endothelin-1 (ET-1) are mediated via ETA-receptors, but the role of ETB-receptors is unclear. We examined the pathophysiologic role of ETB-receptors on ventricular tachyarrhythmias (VT/VF) during myocardial infarction (MI). MI was induced by coronary ligation in two animal groups, namely in wild-type (n = 63) and in ETB-receptor-deficient (n = 61) rats. Using a telemetry recorder, VT/VF episodes were evaluated during phase I (the 1st hour) and phase II (2–24 h) post-MI, with and without prior β-blockade. Action potential duration at 90% repolarization (APD90) was measured from monophasic epicardial recordings and indices of sympathetic activation were assessed using fast-Fourier analysis of heart rate variability. Serum epinephrine and norepinephrine were measured with radioimmunoassay. MI size was similar in the two groups. There was a marked temporal variation in VT/VF duration; during phase I, it was higher (p = 0.0087) in ETB-deficient (1,519 ± 421 s) than in wild-type (190 ± 34 s) rats, but tended (p = 0.086) to be lower in ETB-deficient (4.2 ± 2.0 s) than in wild-type (27.7 ± 8.0 s) rats during phase II. Overall, the severity of VT/VF was greater in ETB-deficient rats, evidenced by higher (p = 0.0058) mortality (72.0% vs. 32.1%). There was a temporal variation in heart rate and in the ratio of low- to high-frequency spectra, being higher (<0.001) during phase I, but lower (p < 0.05) during phase II in ETB-deficient rats. Likewise, 1 h post-MI, serum epinephrine (p = 0.025) and norepinephrine (p < 0.0001) were higher in ETB-deficient (4.20 ± 0.54, 14.24 ± 1.39 ng/ml) than in wild-type (2.30 ± 0.59, 5.26 ± 0.67 ng/ml) rats, respectively. After β-blockade, VT/VF episodes and mortality were similar in the two groups. The ETB-receptor decreases sympathetic activation and arrhythmogenesis during the early phase of MI, but these effects diminish during evolving MI.     

Isolated noncompaction of the ventricular myocardium: contemporary diagnosis and management

Noncompaction of the ventricular myocardium is a rare form of cardiomyopathy that has been described since the early 1990s. However, noncompaction remains frequently overlooked, in part due to the limited awareness of its unique clinical and imaging characteristics. Contemporary diagnosis has been facilitated by the introduction of specific morphologic criteria by echocardiography and cardiac magnetic resonance. Management issues revolve around the management of heart failure, arrhythmias, and thromboembolic events in order to prevent the significant morbidity and even mortality that has been associated with this entity. Finally, the genetics of noncompaction have been diverse and an issue of clinical importance as it relates to screening of first-degree relatives of affected patients. Two recent cases are presented and many of the contemporary issues in diagnosis and management, based on an extensive review of the literature, are addressed. Copyright (c) 2007 Wiley Periodicals, Inc.     

Effect of surgical incision on pain and respiratory function after abdominal surgery: a randomized clinical trial

BACKGROUND/AIMS: The aim of the present study was to assess the severity of respiratory disturbances occurring after abdominal surgery and to identify surgical incisions that entail the least respiratory complications and postoperative pain. METHODOLOGY: A total of 105 patients divided into two groups were included in this randomized clinical trial. Seventy-five patients in the first group underwent upper abdominal surgery, and were operated on by use of vertical, oblique, transverse and elliptic incision. The remaining 30 patients in the second group were submitted to low abdominal surgery by use of vertical and oblique incision. Arterial blood gases and pulmonary shunt development were determined at 12 h preoperatively, and at 6 h, 72 h and 144 h postoperatively. During the postoperative course, VAS-pain score and use of tramadol were observed according to the type of surgical incision employed. RESULTS: Most severe respiratory disturbances in terms of PaO2 decrease, activating compensatory hyperventilation, pulmonary shunt increase, the highest VAS-pain score and consumption of tramadol were induced by the following upper abdominal incisions: transversal laparotomy according to Orr, elliptic periumbilical laparotomy, upper midline laparotomy, transrectal laparotomy and subcostal laparotomy. In the group of low abdominal surgery (low midline laparotomy and inguinal incision) consumption of tramadol was statistically significantly lower, but no statistically significant differences were recorded between the baseline preoperative and postoperative values of PaO2, PaCO2 and pulmonary shunt. CONCLUSIONS: All low abdominal incisions were found to entail statistically significantly less respiratory disturbances, lower VAS-pain score and lower tramadol use when compared to upper abdominal incisions. The upper abdominal incisions observed caused substantial respiratory disturbances including hypoxia, hyperventilation and pulmonary shunt increase.     

Persistent platelet activation is related to very early cardiovascular events in patients with acute coronary syndromes

INTRODUCTION: Persistent platelet function while on antiplatelet therapy affects outcomes in patients with acute coronary syndromes (ACS). AIM: To evaluate whether platelet reactivity measured by collagen-epinephrine (CEPI) or collagen-ADP (CADP) closure times (CT) with Platelet Function Analyzer 100 (PFA-100) is related to very early, in-hospital cardiovascular events in patients with ACS. METHODS: The study included 91 patients with ACS undergoing percutaneous coronary intervention (PCI) with stent implantation who were treated with aspirin and clopidogrel. Patients were stratified in accordance with both CEPI-CT (<190 s or >190 s), reflecting aspirin resistance, and our own cut-off point for CADP-CT measured at a mean of 6 days after admission. In-hospital events included re-infarction, cardiac arrest, recurrent angina, severe arrythmias, pulmonary oedema and cardiogenic shock. RESULTS: Patients were divided into 4 study groups: group 1 with CADP-CT <104 s (n=10, 11.0%), group 2 with CEPI-CT <190 s (n=10, 11.0%), group 3 with CADP-CT <104 s and CEPI-CT <190 s (n=9, 9.9%) and a control group with both CT values above the cut-off limits (n=62, 68.1%). The baseline clinical characteristics and received treatment of each subgroup were similar. A test for a trend between controls, group 1 or 2 and group 3 disclosed statistical significance (p <0.001). When analysed separately, only patients from group 3 had a higher incidence of negative outcomes compared to controls (p <0.005; relative risk RR - 9.0; 95% CI 2.4-33.9). CONCLUSIONS: Enhanced platelet function after PCI when measured under high shear rates by both PFA-100 cartridges is independently associated with the most unfavourable in-hospital clinical outcome.     

Myocardial asynchrony in patients with postinfarction intraventricular conduction defects

BACKGROUND: Postinfarction intraventricular conduction defects lead to asynchronous activation of the myocardium.Hypothesis: The aim of the current study is to evaluate contraction asynchrony in postinfarction patients with intraventricular conduction defects. METHODS: A total of 158 patients 6 months postmyocardial infarction and 15 healthy subjects underwent echocardiography to evaluate atrioventricular, interventricular, intraventricular asynchrony, and myocardial performance index (MPI). A subgroup of 126 patients had intraventricular conduction defects in ECG, whereas 32 with normal QRS complex served as controls. RESULTS: All patients postmyocardial infarction showed intraventricular asynchrony and markedly higher MPI. Comparing groups with and without intraventricular conduction defects postmyocardial infarction, those with left bundle branch block (BBB) had significantly higher parameters of all asynchrony types; those with right BBB and left posterior hemiblock (LPH) had significantly higher interventricular asynchrony parameters; those with left anterior hemiblock did not show significant differences in asynchrony parameters as compared with subjects without postinfarction conduction defects. CONCLUSIONS: (1) Patients 6 months postmyocardial infarction show intraventricular asynchrony and markedly higher MPI. (2) Postinfarction patients with LBBB have the highest parameters of atrioventricular, interventricular and intraventricular asynchrony as compared with postinfarction patients with other and without conduction defects. (3) In postinfarction patients with RBBB or LPH parameters of interventricular asynchrony are significantly higher as compared with postinfarction patients without intraventricular conduction defects.     

TNF-α and sICAM-1 in intracranial aneurismal rupture

Introduction  Subarachnoidal hemorrhage (SAH) occurring after aneurismal rupture produces an inflammatory response in the cerebral circulation. Tumor necrosis factor (TNF)-α is a major cytokine in this process. Adhesion molecules provide information on inflammatory reactions taking place in the walls of blood vessels. Clinical evidence suggests a role of soluble intercellular adhesion molecule (sICAM)-1 in early hemorrhagic events. This study aimed to evaluate the implementation of early TNF-α and sICAM-1 serum measurement for the prognosis of patient outcome after intracranial aneurismal rupture. Materials and Methods  The study consisted of 27 patients with a diagnosis of intracranial aneurysm. SAH was evaluated on admission according to the Fisher scale, patients’ consciousness with the Glasgow Coma Scale, clinical grading with the Hunt and Hess scale, and clinical outcome with the Glasgow Outcome Scale (GOS). Blood samples were drawn within 72 h after arrival at the emergency room. Serum concentrations of TNF-α and sICAM-1 were assayed with the ELISA method. Results  The initial serum TNF-α concentration in the aneurismal patients was low and did not correlate with radiological and clinical scores. The serum sICAM-1 level positively correlated with the severity of bleeding assessed by the Fisher scale and negatively with the patient’s scoring in the GOS. Conclusions  This study demonstrated the absence of a systemic TNF-α-mediated inflammatory response at the onset of subarachnoid hemorrhage. Early measurement of serum sICAM-1 levels offers a potential prognostic value in the assessment of patients’ outcome after brain aneurismal rupture.     

Psychological and psychiatric factors related to health-related quality of life after total hip replacement - preliminary report

Total hip replacement is one of the most successful orthopaedic interventions in improving considerably the patients' performance, nevertheless some patients demonstrate declined functional ability following an operation. Such condition is not a consequence of medical illness or the surgery itself but might rather be associated with mental status. The authors conduct an investigation concerning the relation between some psychological and psychiatric factors and their influence on health-related quality of life in patients after total hip replacement. METHODS: Into the study group we included 102 subjects undergoing total hip replacement (59 female, 43 male). In all subjects we measured depression (Beck Depression Inventory - BDI), anxiety (State and Trait Anxiety Inventory - STAI), sense of coherence (SOC-29), personality traits (Eysenck Personality Inventory - EPI) and health related quality of life (SF-36). RESULTS: The postoperative values of the PCS and the MCS for the whole group of patients correlated negatively with the SOC values (p=0.04 and p=0.03 respectively). Neuroticism (EPI) and anxiety as a trait (STAI) were also associated with postoperative performance, both in mental (p=0.03 and p=0.008 respectively) and physical (p=0.005 and p=0.04 respectively terms). CONCLUSION: Total hip replacement improves significantly the patient's health-related quality of life at 6months after surgery, what is influenced by sense of coherence, neuroticism and anxiety as a trait. Above mentioned factors should be taken into account when rehabilitation and social readaptation processes are planned.