Although it is technically complex, atriobiventricular pacing significantly improves exercise tolerance and quality of life in patients with chronic heart failure and intraventricular conduction delay.

Background: Cardiac resynchronisation is a promising new intervention for patients with heart failure, left ventricular systolic dysfunction and ventricular dyssynchrony. Objecti¨e: The CARE-HF trial is designed to evaluate the long-term effects Ž . of cardiac atrio-bi-ventricular resynchronisation on the mortality and morbidity of patients with heart failure due to left ventricular systolic dysfunction already receiving diuretics and optimal medical therapy with ACE inhibitors and beta-blockers Ž . where indicated and tolerated . Methods and Results: Approximately 800 patients will be randomised to device therapy or control and followed for a minimum of 18 months. A pragmatic study design has been chosen that does not attempt to conceal allocation from investigators or patients because it is impossible to guarantee maintenance of blinding for the duration of the study. The end-points committee will adjudicate events in a blinded fashion. Since cardiac resynchronisation may alter other aspects of the management of the patient, as would occur in clinical practice, the study should be considered a comparison of strategies rather than simply of a device. The primary end-point is all-cause mortality or unplanned cardiovascular hospitalisation. The study should complete recruitment during

A 54-year-old man received a four chamber pacing system for severe congestive heart failure (NYHA functional Class IV). His ECG showed a left bundle branch block (200-msec QRS duration) with 200-msec PR interval, normal QRS axis, and 90-msec interatrial interval. An acute hemodynamic study with insertion of four temporary leads was performed prior to the implant, which demonstrated a significant increase in cardiac output and decrease of pulmonary capillary wedge pressure. A permanent pacemaker was implanted based on the encouraging results of the acute study. The right chamber leads were introduced by cephalic and subclavian approaches. The left atrium was paced with a coronary sinus lead, Medtronic SP 2188-58 model. An epicardial Medtronic 5071 lead was placed on the LV free wall. The four leads were connected to a standard bipolar DDD pacemaker, Chorus 6234. The two atrial leads were connected via a Y-connector to the atrial channel of the pacemaker with a bipolar pacing configuration. The two ventricular leads were connected in a similar fashion to the ventricular channel of the device. The right chamber leads were connected to the distal poles. The left chamber leads were connected to the proximal poles of the pacemaker. Six weeks later, the patient's clinical status improved markedly with a weight loss of 17 kg and disappearance of peripheral edema. His functional class was reduced to NYHA II. Four chamber pacing is technically feasible. In patients with evidence of interventricular dyssynchrony, this original pacing mode probably provides a mechanical activation sequence closer to the natural one.(ABSTRACT TRUNCATED AT 250 WORDS)

A more favourable outcome of CRT with regard to LV reverse remodelling and the composite of time to death or first HF hospitalization was observed when the LV lead tip was implanted in the lateral wall, away from the apex, while the position of the RV lead tip was indifferent. The long-term change in QRS duration was significantly associated with the position of the LV lead tip. ClinicalTrials.gov Identifier: NCT00271154.