[Cardiac resynchronization in congestive heart failure: role of Doppler echocardiography in patient selection].

Cardiac echodoppler is an efficient tool to analyse cardiac mechanic loop. Diastolic and systolic desynchronisation criteria are analysed. It should allow a more efficient selection of patients who could take benefit of resynchronization therapy, but also to choose resynchronization system, to program optimal atrioventricular delay, interventricular delay and to evaluate resynchronization efficiency.

[Resynchronization of the failing heart by pacing].

Cardiac pacing has been proposed for patients with advanced heart failure refractory to optimal drug treatment and having conduction disorders to resynchronize mechanical activity of the heart. Activation asynchronism as caused by bundle branch block results in alteration of systolic function and arrhythmias. A too short or too long atrio-ventricular delay can also affect diastolic ventricular filling.

Atrioventricular cross-talk in biventricular pacing: a potential cause of ventricular standstill.

The aim of the study was to evaluate, in recipients of biventricular pacing systems, the risk of asystole due to ventricular pacing inhibition by sensing the left atrial signals by the LV lead at conventional sensitivity. Long-term ventricular sensitivity was programmed at > or = 4 m V in 17 consecutive recipients of ventricular resynchronization systems implanted for chronic management of congestive heart failure. Ventricular pacing inhibition due to AV cross-talk on spontaneous left atrial electrogram (AVCSA) was tested at a 2 mV ventricular sensitivity immediately after implantation of the stimulation system and 1 month later.