Acute electromechanical effects of atrioventricular coupled pacing in patients with heart failure.

BACKGROUND: Postextrasystolic potentiation (PESP) is a property of cardiac tissue whereby two closely timed depolarizations cause the subsequent contraction to be of increased magnitude. METHODS AND RESULTS: Ten subjects were studied in a single-blind study to evaluate the safety and performance of an atrioventricular coupled pacing (A-VCP) algorithm to produce sustained PESP among subjects with moderate heart failure. The primary end points were algorithm safety, patient perception, and cardiac function. The effects of A-VCP on cardiac function were assessed by comparing echocardiographic parameters before and after 15 to 20 minutes of A-VCP. A-VCP produced no arrhythmic episodes, ejection fraction increased by 8 ejection fraction points (31%) (P < or = .001), end-systolic volume decreased by 10% (P < or = .05), and a trend toward increasing end-diastolic volume was observed (P = .084). Stroke volume increased by 43% (P < or = .001), and the pulse rate decreased by 41% (P < or = .001) during A-VCP. This resulted in decreased cardiac output of 15% (P < or = .05). Six of the 10 subjects felt no effects from A-VCP, and four subjects felt a change with A-VCP turned on. CONCLUSION: Short-term A-VCP was found to be safe and well tolerated in a majority of patients. Hemodynamic effects were mixed with improved ejection fraction and stroke volume but decreased cardiac output.

Robotic mitral valve repair: a community hospital experience.

Robotically assisted cardiac surgery has been presented as less invasive than conventional surgery, with shortened hospital stays and faster return to daily activities. We evaluated our experience with the da Vinci robot to determine whether we could in fact demonstrate those findings. All mitral and tricuspid valve repairs were performed by the same surgeon. Cardiopulmonary bypass was performed with femoral cannulation, antegrade cardioplegia, and transthoracic aortic cross-clamping. Multiple valve repair techniques were used, including quadrant resection, cord replacement, Alfieri leaflet coaptation, and ring annuloplasty. Access was by 2 ports and a 5-cm right anterolateral thoracotomy. All annuloplasty rings were secured using surgical clips. From October 2003 through September 2004, 32 patients underwent robotically assisted mitral valve repair. The mean age of our population was 676 years (range, 43-82 years). Four patients also underwent the 1st tricuspid valve repair using the da Vinci robot in the United States. There were 3 conversions for irreparable valves, 1 stroke, and 2 deaths. The average procedure time, cardiopulmonary bypass time, and aortic cross-clamp time were all reduced, when the first 20 patients were compared with the last 12. Length-of-stay also improved. One patient required early mitral valve replacement for recurrent regurgitation. Two patients required late (> 3 month) mitral valve replacement for recurrent regurgitation. We have shown that a dedicated nonacademic institute can develop a robotic cardiac surgery program and perform mitral and tricuspid valve repairs successfully. There is a several-case learning curve, and patient selection is paramount.