Optimization therapy of cardiac stimulation - Optics

Abstract

The endocavitary pacing of the right ventricle is recognized as safe and effective in the treatment of symptomatic bradyarrhythmias. However, recent studies have associated this type of stimulation to deleterious effects responsible for installation or worsening of heart failure in patients with reduced left ventricular ejection fraction - LVEF (<35 or 40%). Our hypothesis is that the conventional right ventricular pacing, after optimization of atrioventricular interval (iAV), should not be deleterious, in terms of clinical and functional parameters, to patients with pacemaker and LVEF between 35 and 55%. Objectives: To compare the clinical, functional and quality of life behaviour after programming pacemaker with empirical iAV or optimized by intracavitary electrocardiography or by echocardiography in patients with pacemaker and moderate ventricular dysfunction. Primary outcome: Change in left ventricular end-diastolic volume index (iVDFVE) and left ventricular end-systolic volume index (iVSFVE). Secondary outcomes: change in functional class of heart failure (HF), the rate of hospitalization for HF, the Quality of Life score, and cardiac index and LV systolic volume evaluated by impedance cardiography - CardioZ. Methods: unicentric, randomized, parallel, blinded to the patient. The series is estimated in 105 consecutive patients who underwent pacemaker implantation for atrioventricular block. The follow-up will be 1 year. The randomization will distribute the series in: Group I - empirical iAV programming, Group II - optimization of the iAV by intracavitary electrocardiography (proper function of the pacemaker) and Group III - optimization of iAV by echocardiogram. All patients should undergo the following assessments before and after the study: clinical, quality of life questionnaires (SF-36 and AQUAREL), CardioZ and echocardiogram. Expected results: Optimization of iAV is expected to remain stable clinical and functional parameters in patients with pacemaker and LVEF between 35 and 55%, to define the best method for this optimization should reduce the risk of worsening heart failure by right ventricular pacing and identify indicators of progressive worsening of heart failure after right ventricular pacing. (AU)