Background

1. Financial Disclosure Conclusions Methods Results Background Biventricular Pacing is Not Associated with Proarrythmic Effects in Patients with Left Ventricular Dysfunction Adam S. Budzikowski, MD, PhD, Ofek Y. Hai, DO, Cristina A. Mitre MD, Opesanmi Esan, MD, Ayotunde Bamimore, MD, John Kassotis, MD SUNY Downstate, Division of Cardiovascular Medicine—EP Section. 450 Clarkson Ave Box 1199, Brooklyn, NY 11203 USA. • STUDY DESIGN • Retrospective cohort study of 24 consecutive patients with severe LV dysfunction that have undergone an upgrade from a single chamber defibrillator to a biventricular defibrillator because of worsening heart failure status. All patients undergone ICD implantation for primary prevention of sudden cardiac death. • Arrhythmic burden was measured as sum of NSVT, VT, and VF episodes requiring ATP or shock for termination. • All analyzed events were faster than 170bpm. • Only events in the six months prior and post upgrade were analyzed to limit the influence of remodeling. • ANALYSIS • Paired T-test was used to compare cumulative ventricular events in pre-CRT vs. post CRT groups. • ANOVA was used to investigate whether LV lead positioning post CRT was associated with increased or decreased frequency of ventricular arrhythmias. Cardiac Resynchronization Therapy (CRT) has emerged as an effective treatment modality in patients with advanced heart failure. CRT significantly improves cardiac output, quality of life, and NYHA functional class. However, little is known about the consequences of reversing the direction of activation of the LV wall. Multiple case reports and basic science studies seem to suggest that biventricular pacing in patients with severe left ventricular dysfunction may be associated with proarrhythmic effects despite improvement in survival. Most published studies that attempted to ascertain this issue suffer lack of true control population. To avoid this difficulty, we compared the ventricular arrhythmic burden in patients who underwent an upgrade from single chamber to a biventricular defibrillator. Our objective was to determine if biventricular pacing in patients with LV dysfunction is associated with change in frequency of ventricular arrhythmias. Baseline Characteristics (25 patients) • There was no change in the frequency of ventricular arrhythmias pre vs. post CRT. The cumulative burden of ventricular events pre-upgrade vs. post upgrade was 8.75±5.06 and 7.71±2.77 respectively, (p=NS) • LV lead positioning (seen here) and LV lead location (not shown) have no significant effect on frequency of ventricular arrhythmias (P=NS) p=NS A B Although there was an improvement in the functional status of the patients, no significant remodeling of the left ventricle was seen. This may account for the absence of change in the burden of ventricular arrhythmias following the upgrade to resynchronization system. ASB-speakers bureau Zoll, Honoraria Boston Scientific and St. Jude Medical. CM, OE, AB – Fellowship support Medtronic, Boston Scientific, St. Jude Medical. JK – speakers Bureau Medtronic, Zoll.