Long-Term Follow-up of Atrioventricular Delay Optimization in Patients With Biventricular Pacing

Abstract

he efficacy of a short atrioventricular (AV) delay in patients with severely impaired cardiac function has been reported, 1-5 but right ventricular pacing during AV sequential pacing has deleterious effects. 6 It has been reported that biventricular pacing can improve the hemodynamics in patients with congestive heart failure, [7][8][9][10] and as both AV delay optimization and shortening of the ventricular activation sequence are important in patients with severely impaired cardiac function, 11 AV delay optimization may also be important during biventricular pacing. 5 However, the optimal AV delay may not be a fixed value in each patient and may need to be frequently calculated.Diastolic mitral regurgitation (MR) is observed in patients with elevated left ventricular end-diastolic pressure 12 and can be induced by prolonging the AV delay in patients with DDD pacemakers. [5][6][12][13][14][15][16][17][18][19] Cardiac function may be improved by AV sequential pacing and setting the AV delay under the critical PQ interval for the appearance of diastolic MR when diastolic MR is observed in patients with intrinsic AV conduction. [4][5][6] We have determined a formula 16 for predicting the optimal AV delay using Doppler echocardiography: optimal AV delay = slightly prolonged AV delay -the interval between the end of the atrial kick and complete closure of the mitral valve (duration of diastolic MR) at the AV delay setting (Fig 1).In this study, we evaluated the efficacy of our method of Circulation Journal Vol.69, February 2005AV delay optimization using Doppler echocardiography in patients with biventricular pacing. MethodsThe study included 5 consecutive patients ranging in age from 60 to 77 years (67.4±8.0; mean ± SD) with severe congestive heart failure and an implanted biventricular pacemaker selected between December 1999 and September 2001. New York Heart Association (NYHA) class was III-IV before biventricular pacemaker implantation. Two (40%) of the 5 patients were taking angiotensin-converting enzyme inhibitors, 2 (40%) were receiving angiotensin-receptor blockers, 3 (33%) were receiving digitalis, 1 (20%) was receiving nitrates, and 5 (100%) were receiving diuretics. Beta-blockers were not prescribed in any patient because of the severe hypotension and bronchial asthma. Patients with chronic atrial fibrillation were excluded. Four patients had idiopathic dilated cardiomyopathy and one had ischemic cardiomyopathy. The LV ejection fraction was 23.6±7.1%.Optimal AV delay was predicted by our method. 16 Cardiac output (CO) and diastolic filling time were measured by Doppler echocardiography when the AV delay was set at the predicted optimal AV delay, the predicted optimal AV delay -25 ms and the predicted optimal AV delay + 25 ms.The follow-up period was 2.3±1.1 (0.8-3.8) years after biventricular pacemaker implantation. We evaluated the severity of congestive heart failure by NYHA class and the optimal AV delay was estimated every 3-6 months (Fig 2). When the end of the A wave on transmitral flow coincided wi...

Contractility sensor-guided optimization of cardiac resynchronization therapy: results from the RESPOND-CRT trial

“…Such a variance between patients emphasizes the need for a patient-centric approach to program the AV and VV timings, to help maximize cardiac synchrony and the consequent increase in cardiac contractility 7 . The optimal AV interval is integral to enhancing response to CRT, and a suboptimal AV interval may contribute to a decline in cardiac output, by up to 20% 23 , 24 . Even though tailoring the delivery of CRT with AV and VV optimization is considered best practice, this has neither been adopted as a part of routine clinical care nor supported by the ESC 2013 guidelines 1 .…”

Primary Results From the SmartDelay Determined AV Optimization: A Comparison to Other AV Delay Methods Used in Cardiac Resynchronization Therapy (SMART-AV) Trial

“…13,14 Suboptimal AV delay programming can result in as much as a 10% to 15% decline in cardiac output. 15,16 However, the large-scale randomized clinical trials establishing the overall efficacy of CRT have differed widely in their approach to AV optimization. In the CONTAK CD trial, there was no AV optimization.…”

Cardiac Resynchronization Therapy: Variations in Echo‐Guided Optimized Atrioventricular and Interventricular Delays During Follow‐Up

“…Echocardiography plays a central role in appropriate selection and follow‐up of CRT patients 9,10 . In particular, echocardiographic optimization of AV and VV delay has been shown to further improve LV systolic performance by individually tailoring the sequence of ventricular activation 11–24 . In clinical practice, routine performance of echocardiographic optimization is limited by several factors, including time requirement and lack of a standard protocol.…”

“…The hemodynamic benefit and temporal variations of echocardiographic optimization of AV and VV delay have been analyzed in the first months after CRT device implantation 11,13 . However, relatively few data are available about optimal AV and VV programming during long‐term follow‐up 15,20,25 . We therefore prospectively investigated the variations in AV and VV delay among patients receiving echocardiographically guided programming of a CRT device at the time of implantation and at 6 and 12 months.…”