Prediction of Optimal Atrioventricular Delay in Patients with Implanted DDD Pacemakers

Abstract

In patients with an implanted DDD pacemaker (PM), the atrial contribution may be interrupted by too short an atrioventricular (AV) delay, and filling time may be shortened by too long an AV delay. The AV delay at which the end of the A wave on transmitral flow coincides with complete closure of the mitral valve may be optimal. The subjects were 15 patients [70.3+/-12.3 (SD) years old] with an implanted DDD PM. Cardiac output (CO) and pulmonary capillary wedge pressure (PCWP) were measured by Swan-Ganz catheter. Transmitral flow was recorded by pulsed Doppler echocardiography. AV delay was prolonged stepwise by 25 msc. When the AV delay was set at 155+/-26 ms, the end of the A wave coincided with complete closure of the mitral valve. When the AV delay was prolonged 25, 50, 75, and 100 ms from this AV delay, the interval between the end of the A wave and complete closure of mitral the valve was prolonged 16+/-5, 39+/-6, 65+/-4 and 88+/-5 ms, respectively (r = 0.97, P<0.0001) and diastolic mitral regurgitation was observed during this period. Thus, the optimal AV delay may be predicted as follows: the slightly prolonged AV delay minus the interval between the end of the A wave and complete closure of the mitral valve. When the AV delay was set at 215 ms, there was a significant positive correlation between the predicted optimal AV delay (166+/-23 ms) and the optimal AV delay (CO: 161+/-26 msec, r = 0.93, P<0.0001, PCWP: 161+/-28 msec, r = 0.95, P<0.0001). In conclusion, optimal AV delay can be predicted by this simple formula: slightly prolonged AV delay minus the interval between end of A wave and complete closure of mitral valve at the AV delay setting.

Optimization of Atrioventricular Delay and Follow-up in a Patient With Congestive Heart Failure With an Implanted DDD Pacemaker

“…11 In our previous studies, diastolic MR was detected during the interval between the end of the A wave and complete closure of the mitral valve, and the critical PQ interval that induces diastolic MR may represent the upper limit of the optimal PQ interval. [4][5][6][7][8][9][10][11][12] We devised a simple method for predicting the optimal AV delay: slightly prolonged AV delay -interval between the end of the atrial kick and complete closure of the mitral valve (duration of diastolic MR) at the AV delay setting. 12 DDD pacing and AV delay optimization are not always effective for congestive heart failure and the indication for this therapy remains unclear.…”

“…[4][5][6][7][8][9][10][11][12] We devised a simple method for predicting the optimal AV delay: slightly prolonged AV delay -interval between the end of the atrial kick and complete closure of the mitral valve (duration of diastolic MR) at the AV delay setting. 12 DDD pacing and AV delay optimization are not always effective for congestive heart failure and the indication for this therapy remains unclear. The present patient had a prolonged PQ interval and complete left bundle branch block and was, therefore, a good candidate for short AV delay therapy.…”

“…11 We have determined a new formula for predicting the optimal AV delay using Doppler echocardiography: optimal AV delay = slightly prolonged AV delay -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). 12 We report a patient with severe congestive heart failure who remained in good condition for more than 4 years with pacemaker implantation and AV delay optimization. …”

“…[5][6][7][8][9][10][11][12] Cardiac function may be improved by AV sequential pacing and by setting the AV delay at less than the critical PQ interval for the appearance of diastolic MR when the latter is observed in patients with intrinsic AV conduction. 11 We have determined a new formula for predicting the optimal AV delay using Doppler echocardiography: optimal AV delay = slightly prolonged AV delay -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).…”

Novel Method of Predicting the Optimal Atrioventricular Delay in Patients With Complete AV Block, Normal Left Ventricular Function and an Implanted DDD Pacemaker

“…To determine the optimal AV delay, pulsed Doppler echocardiography is commonly used, 4 and our method was reported previously. 5,[7][8][9][10][11][12][13] However, echocardiography has several problems. The examination is time-consuming, and the optimal AV delay varies from patient to patient and with the patient's heart rate during exercise, sleep and other activities.…”