[Show abstract][Hide abstract] ABSTRACT: Right ventricular apical pacing-related heart failure is reported in some patients after long-term pacing. The exact mechanism is not yet clear but may be related to left ventricular dyssynchrony induced by right ventricular apical pacing. Right ventricular septal pacing is thought to deteriorate left ventricular function less frequently because of a more normal left ventricular activation pattern.
We report the case of a 55-year-old Tunisian woman with preserved ventricular function, implanted with a dual-chamber pacemaker for complete atrioventricular block. Right ventricular septal pacing induced a major ventricular dyssynchrony, severe left ventricular ejection fraction deterioration and symptoms of congestive heart failure. Upgrading to a biventricular device was associated with a decrease in the symptoms and the ventricular dyssynchrony, and an increase of left ventricular ejection fraction.
Right ventricular septal pacing can induce reversible left ventricular dysfunction and heart failure secondary to left ventricular dyssynchrony. This complication remains an unpredictable complication of right ventricular septal pacing.
[Show abstract][Hide abstract] ABSTRACT: B-type natriuretic peptide (BNP) is a biomarker of cardiovascular disease that is common in adults with chronic kidney disease (CKD). However, in children with CKD, the range and predictive power of BNP concentrations are not known. We aimed to determine the effect of HD on BNP, as well as the prognostic impact of BNP, in end-stage renal disease (ESRD) children undergoing hemodialysis (HD). Thirty-five children with chronic renal failure (16 boys age 12.1 ± 3.7 years) on maintenance HD were included. BNP level was measured, and Doppler echocardiography was performed 30 min before (pre-HD BNP) and 30 min after (post-HD BNP) HD in each patient. An adverse event was defined as all-cause death and heart failure hospitalization. The median pre-HD BNP, the post-HD BNP, and the change in BNP were, respectively, 240 pg/ml (72 to 3346), 318 pg/ml (79 to 3788), and 9 pg/ml (-442 to 1889). Pre-HD BNP concentration was negatively correlated with left ventricular (LV) ejection fraction (r = -0.41, P = 0.018). During a mean follow-up of 39 ± 14 months, 6 patients died, and 3 were hospitalized for heart failure. Using univariate analysis, BNP before and after HD as well as Doppler tissue imaging velocities had a strong graded relationship with adverse events. Cox proportional hazards model demonstrated that pre-HD body weight (P = 0.008), pre-HD BNP (P = 0.011), and post-HD BNP (P = 0.038) remained independent predictors of adverse outcome. Even in case of ESRD, BNP still strongly correlated with LV systolic and diastolic dysfunction and was associated with mortality in HD children.
[Show abstract][Hide abstract] ABSTRACT: Despite clinical importance of ventricular repolarisation, it remains difficult to analyse. Conventionally, quantification of the electrocardiographic ventricular repolarization is usually performed with reference to axis of the T wave and QT interval duration. A variety of factors can prolong the QT interval, such as drug effects, electrolyte imbalances, and myocardial ischemia. The biggest risk with prolongation of the QT interval is the development of torsades de pointes. Commonly accepted reference ranges for the electrocardiogram (ECG) have been in use, with little change, for many years. Populations throughout the world present several differences: age, ethnic compositions, and are exposed to different environmental factors. Recent studies have reported reference data for QT interval in healthy population and have evaluated the influence of age, gender, QRS duration and heart rate on this interval. In this review, we address several issues relative to the measurement, and interpretation of QT interval and its adjustment for rate, age, gender and QRS duration.
Annales de cardiologie et d'angeiologie 01/2011; 61(1):42-8. · 0.21 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Introduction: No data regarding the prevalence of the Brugada-type electrocardiogram (ECG) pattern and the early ventricular repolarization pattern (ERP) in the North African population were available. The aims of this study were to determine the frequency of Brugada-type ECG pattern and ERP in Tunisia and to evaluate ECG descriptors of ventricular repolarization in a population of athletes. Methods: Over a 2-year period, resting 12-lead ECG recordings were analyzed from athletes (n = 540; 348 males; age 18.3 ± 2.4 years). Brugada-type ECG pattern was defined as Type 1, 2, or 3, and ERP was characterized by an elevation of the J point in the inferior and/or lateral leads. The population was divided into three groups of athletes: ERP group; Brugada-type ECG pattern group; and control group, with neither ERP nor Brugada ECG pattern. Clinical and electrocardiographic parameters were compared among the study groups. Results: Nine subjects (1.66%) had a Brugada-type ECG pattern. None of them had the coved-type, 3 (0.6%) had the Type 2, and 6 (1.1%) had the Type 3. All subjects were asymptomatic. A Brugada-type ECG pattern was observed in seven males. No female had the Type 2 Brugada ECG pattern. ECG parameters were similar among Brugada-type ECG pattern and control athletes. ERP (119 subjects, 22%) was obtained in 98 males. Heart rate was lower, the QRS duration shorter and QT and T peak –T end intervals were longer in ERP than control groups. Conclusion: The results indicate that the frequency of the Brugada-type ECG pattern and ERP were respectively 1.66% and 22.00% in athletes, being more prevalent in males. The ERP group experienced shorter QRS duration and longer T peak –T end interval than in the control population.
Open Access Journal of Sports Medicine 01/2011; 2:33-40.
[Show abstract][Hide abstract] ABSTRACT: PurposeContrasting data exist about the hemodialysis induced changes of ventricular diastolic and systolic functions in adults. Few data in children with end-stage renal disease (ESRD) are reported. The aim of the present study was to evaluate the effect of a single hemodialysis (HD) session on left ventricular (LV) systolic and diastolic function using conventional pulsed-Doppler echocardiography and pulsed tissue Doppler imaging (TDI) in hemodialysis children.
Annales de Cardiologie et d Angéiologie 02/2010; 59(1):14-19. · 0.30 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Dual-chamber pacing is believed to have an advantage over single-chamber ventricular pacing. The aim of the study was to determine whether elderly patients with implanted pacemaker for complete atrioventricular block gain significant benefit from dual-chamber (DDD) compared with single-chamber ventricular demand (VVIR).
The study was designed as a double-blind randomized two-period crossover study-each pacing mode was maintained for 3 months. Thirty patients (eight men, mean age 76.5 +/- 4.3 years) with implanted PM were submitted to a standard protocol, which included an interview, functional class assessment, quality of life (QoL) questionnaires, 6-minute walk test, and transthoracic echocardiographic examinations. QoL was measured by the SF-36. All these parameters were obtained on DDD mode pacing and VVIR mode pacing. Paired data were compared.
QoL was significantly different between the two groups and showed the best values in DDD. Overall, no patient preferred VVIR mode, 18 preferred DDD mode, and 12 expressed no preference. No differences in mean walking distances were observed between patients with single-chamber and dual-chamber pacing. VVI pacing elicited marked decrease in left ventricle ejection fraction and significant enlargement of the left atrium. DDD pacing resulted in significant increase of the peak systolic velocities in lateral mitral annulus and septal mitral annulus. Early diastolic velocities on both sides of mitral annulus did not change.
In active elderly patients with complete heart block, DDD pacing is associated with improved quality of life and systolic ventricular function compared with VVI pacing.
Pacing and Clinical Electrophysiology 12/2009; 33(5):583-9. · 1.75 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Contrasting data exist about the hemodialysis induced changes of ventricular diastolic and systolic functions in adults. Few data in children with end-stage renal disease (ESRD) are reported. The aim of the present study was to evaluate the effect of a single hemodialysis (HD) session on left ventricular (LV) systolic and diastolic function using conventional pulsed-Doppler echocardiography and pulsed tissue Doppler imaging (TDI) in hemodialysis children.
Thirty-five children with chronic renal failure (15 males, aged 12.8+/-3.8 years) on maintenance hemodialysis underwent conventional 2D and Doppler Echo together with measurement of longitudinal mitral annular motion velocities. Echocardiographic parameters were obtained 30 minutes before and 30 minutes after HD. Paired data were compared.
Hemodialysis led to reduction in LV end-diastolic volume (p=0.001), end-systolic volume (p=0.05), left atrium area (p<0.0001), peak early (E wave) transmitral flow velocity (p=0.005), peak S velocity of pulmonary vein flow (p=0.002), aortic time velocity integral (p<0.0001) and aortic ejection time (p<0.0001). No significant change in Tei Index was observed after HD. Regarding TDI measures, velocities were not affected by preload reduction. Only the early diastolic velocities on the septal side of the mitral annulus decreased significantly (p=0.001) and the systolic velocities on the lateral side of the mitral annulus increased significantly (p=0.042) after hemodialysis.
Most of Doppler-derived indices of diastolic function are preload-dependent. TDI velocities and Tei Index were not or minimally affected by preload reduction in hemodialysis children.
Annales de cardiologie et d'angeiologie 10/2009; 59(1):14-9. · 0.21 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: There is a lack of Tunisian data on the frequency and clinical significance of different coronary artery anomalies.
All patients who underwent coronary angiography from March 1996 to December 2006 were considered. Only patients with congenital anomalous aortic origin of the coronary artery were included.
Among 7330adult patients who underwent diagnostic coronary angiography, 20 (0.27%) patients (13men; mean age 53.3years) had anomalies of the coronary artery origin. The right coronary artery was the vessel involved most frequently (n=10); it originated separately from the left sinus of Valsalva (SV) in three patients and from the posterior sinus of Valsalva in one patient. In the other patients, it arose from the left main coronary artery or its branches in a single coronary artery originating from the left sinus of Valsalva. Isolated anomalous left circumflex artery was the second most frequent anomaly (n=6). Isolated anomalous left anterior descending artery was seen in one patient. A single coronary artery arising from the right SV was seen in three patients. Atheroslerotic lesions were seen in eight cases. Four patients underwent coronary revascularization; the remainder received medical management. All 20 patients are alive and had an uneventful follow-up (mean 34.2months).
In Tunisia, the incidence of congenital anomalous aortic origin of the coronary artery in adults is 0.27%. The right coronary artery is involved most frequently. Medical management seems promising.
Archives of Cardiovascular Diseases 04/2009; 102(3):201-8. · 1.66 Impact Factor