Upgrading from single chamber right ventricular to biventricular pacing in permanently paced patients with worsening heart failure: The RD-CHF Study.

BACKGROUND: Biventricular (BiV) stimulation lowers morbidity and mortality in patients with drug-refractory congestive heart failure (CHF), depressed left ventricular (LV) function, and ventricular dyssynchrony in absence of indication for permanent cardiac pacing. This pilot, single-blind, randomized, cross-over study examined the safety and efficacy of upgrading conventional pacing systems to BiV stimulation in patients with advanced CHF. METHODS: We included 56 patients in New York Heart Association (NYHA) functional classes III or IV despite optimal drug treatment and ventricular dyssynchrony (interventriclar delay > 40 ms or LV preejection delay > 140 ms) in need of pacemaker replacement. We compared the patients' functional status, arrhythmias, and standard echocardiographic measurements during 3 months of conventional, single right ventricular (RV) versus 3 months of BiV stimulation. RESULTS: There were 44 patients in the cross-over phase. QRS duration was shortened by 23% and LV preejection delay by 16% with BiV stimulation. NYHA functional class, 6-minute hall walk and quality of life score were significantly improved with BiV stimulation compared with single RV pacing by 18%, 29%, and 19%, respectively. No significant difference was observed in the ventricular arrhythmia burden or LV reverse remodeling between the 2 periods. CONCLUSIONS: This pilot study showed that upgrading from RV pacing to BiV pacing significantly improves symptoms and exercise tolerance in chronically paced patients with advanced CHF and mechanical dyssynchrony.

Management of atrial tachyarrhythmias: benefits of pacemaker diagnostics.

The aim of this prospective multicenter study was to assess the clinical benefits of the Selection (Vitatron) pacemaker diagnostic functions (AF 1.0) in the management of AF. Forty patients (71 +/- 9 years of age), with documented AF and conventional pacing indications, received a Selection. The AF 1.0 function of the pacemaker was programmed to document the AF burden, onset, daily distribution, duration, premature atrial beats before onset, and mode of onset of the last 12 episodes for AF episodes exceeding 180 beats/min. By comparing patients' symptoms records, patient conventional assessment at follow-up and AF 1.0 data, the investigators evaluated the usefulness of AF 1.0 in AF management at 3- and 6-month follow-ups. Usefulness was defined as a change in arrhythmia management prompted by the disclosure of AF 1.0 data. AF recurrences were recorded in 71% of the follow-ups with symptoms reported by patients in only 16%. Thirty-nine percent of therapeutic changes based on conventional assessment were confirmed by AF 1.0 data, and in 61% of instances, the initial changes were modified by AF 1.0 data. Changes included pacing parameters in 56% of cases, AF prevention with pacing algorithms in 37%, and medical treatment in 7%. All investigators indicated that AF 1.0 was useful in all patients. The AF 1.0 diagnostic functions offered a unique documentation of AF in asymptomatic patients, and allowed therapeutic adjustments impossible otherwise.