Septal versus apical pacing sites in permanent right ventricular pacing: The multicentre prospective SEPTAL-PM study.

BACKGROUND: The optimal right ventricular pacing site for patients requiring pacemaker implantation for permanent atrioventricular block is a matter of debate. Long-term right ventricular apical pacing has been associated with left ventricular ejection fraction impairment and heart failure. Right ventricular septal pacing has been proposed as an alternative. AIM: The aim of this randomized prospective multicentre trial was to compare left ventricular remodelling and outcomes between right ventricular apical and septal pacing after mid-term follow-up. METHODS: Patients requiring pacemaker implantation for high-degree atrioventricular block were enrolled and randomized in a 1:1 fashion to receive a right ventricular apical or septal lead. RESULTS: A total of 141 patients were included, 69 in the septal group and 72 in the apical group. Both groups exhibited similar left ventricular ejection fractions after 18 months of follow-up (septal 57.1±11.9% vs. apical 57.4±13.4%), and left ventricular ejection fraction variation was similar in the two groups at the end of follow-up (septal -1.5±13.2% vs. apical 0.3±13.3%). Additionally, left ventricular volume, quality of life and 6-minute walk distance were similar in the two groups. However, patients in the septal group were more likely to be asymptomatic, with a significantly lower concentration of N-terminal prohormone of brain natriuretic peptide. Lastly, lead position did not impact 18-month survival. CONCLUSION: Pacing from the right ventricular apex does not have any detrimental effect on left ventricular systolic function compared with septal pacing over an 18-month period.

Defibrillation testing in everyday medical practice during implantable cardioverter defibrillator implantation in France: analysis from the LEADER registry.

BACKGROUND: Defibrillation testing (DT) is usually performed during implantable cardioverter defibrillator (ICD) implantation. AIMS: We conducted a multicentre prospective study to determine the DT procedures used in everyday practice, to compare the characteristics of patients with or without DT, and to compare severe adverse events in these two populations during implantation and follow-up. METHODS: The LEADER registry enrolled 904 patients included for primo-implantation of a single (n=261), dual (n=230) or triple (n=429) defibrillation system in 42 French centres. RESULTS: Baseline characteristics of patients (62.0 ± 13.5 years; 88% men; primary indication 62%) who underwent ventricular fibrillation (VF) induction (VF induction group, n=810) and those who did not (untested group, n=94, representing 10.4% of the entire study population) revealed that the untested group were older (P<0.01), had a lower left ventricular ejection fraction, a wider QRS complex and a higher New York Heart Association class and were more often implanted for primary prevention (P<0.001 for all). The main reason given for not performing ICD testing was poor haemodynamic condition (59/94). At 1 year, the cumulative survival rate was 95% in tested patients and 85% in untested patients (P<0.001), mainly because of heart failure deaths. There was one sudden cardiac death in the VF induction group and none in the untested group (P=1.000). CONCLUSIONS: In this study, more than 10% of ICD patients were implanted without VF induction. Untested patients appeared to be sicker than tested patients, with a more severe long-term outcome, but without any difference in mortality due to arrhythmic events.

Programming optimal atrioventricular delay in dual chamber pacing using peak endocardial acceleration: comparison with a standard echocardiographic procedure.

Optimization of programmed atrioventricular delay in dual chamber pacing is essential to the hemodynamic efficiency of the heart. Automatic AV delay optimization in an implanted pacemaker is highly desirable. Variations of peak endocardial acceleration (PEA) with AV delay at rest correlate well with echocardiography derived observations, particularly with end-diastolic filling and mitral valve closure timings. This suggests the possibility of devicing a procedure for the automatic determination of the optimal AV delay. The aim of this study was to compare a proposed algorithm for optimal AV delay determination with an accepted echocardiographic method. Fifteen patients with high degree AV block received BEST-Living pacing systems. Automatic AV delay scans were performed at rest (60-300 ms in 20-ms steps with 60 beats per step) in DDD at 90 ppm, while simultaneously recording cycle-by-cycle PEA values, which were averaged for each AV delay to obtain a PEA versus AV delay curve. Nonlinear regression analysis based on a Boltzmann sigmoid curve was performed, and the optimal AV delay (OAVD) was chosen as the sigmoid inflection point of the regression curve. The OAVD was also evaluated for each patient using the Ritter echocardiographic method. Good sigmoid fit was obtained in 13 of 15 patients. The mean OAVD obtained by the PEA sigmoid algorithm was 146.9 +/- 32.1 ms, and the corresponding result obtained by echocardiography was 156.4 +/- 34.3 ms (range 31.8-39.7 ms). Correlation analysis yielded r = 0.79, P = 0.0012. In conclusion, OAVD estimates obtained by PEA analysis during automatic AV delay scanning are consistent with those obtained by echocardiography. The proposed algorithm can be used for automatic OAVD determination in an implanted pacemaker pulse generator.