AIMS: This study was designed to evaluate the effect of variation of atrioventricular (AV) interval (AVI) on left ventricular (LV) diastolic function and ANP and c-GMP levels during DDD pacing in patients with complete AV block and normal systolic function. METHODS: The study population comprised 22 patients (mean age 65.2+/-14.3, 12 males) with complete AV block. All patients underwent complete Doppler echocardiography before implantation of a DDD-pacemaker. Twenty-four hours later, patients were paced for a period of 30 min, at three different AVIs (100 ms, 150 ms and 200 ms), at rest. During each pacing period, Doppler-derived LV diastolic indices were re-evaluated and ANP and c-GMP levels were reassessed. RESULTS: Overall comparison showed a significant progressive augmentation, from 200 ms to 100 ms AVI, in transmitral E/A wave ratio (from 0.53+/-0.13 to 0.90+/-0.25, P = 0.0005) and in LV filling time (from 0.33+/-0.05 to 0.40+/-0.06s, P = 0.0005), followed by a significant progressive reduction in ANP and c-GMP levels. An AVI of 100 ms or 150 ms was associated with improved diastolic indices and lower natriuretic peptides levels, compared with the longer AVI. CONCLUSION: Programmed AVI during DDD pacing affects LV diastolic performance and plasma ANP and c-GMP levels. The assessment of these parameters constitutes a useful modality for AVI optimization.
AIMS: This study was designed to evaluate the effect of variation of atrioventricular (AV) interval (AVI) on left ventricular (LV) diastolic function and ANP and c-GMP levels during DDD pacing in patients with complete AV block and normal systolic function. METHODS: The study population comprised 22 patients (mean age 65.2+/-14.3, 12 males) with complete AV block. All patients underwent complete Doppler echocardiography before implantation of a DDD-pacemaker. Twenty-four hours later, patients were paced for a period of 30 min, at three different AVIs (100 ms, 150 ms and 200 ms), at rest. During each pacing period, Doppler-derived LV diastolic indices were re-evaluated and ANP and c-GMP levels were reassessed. RESULTS: Overall comparison showed a significant progressive augmentation, from 200 ms to 100 ms AVI, in transmitral E/A wave ratio (from 0.53+/-0.13 to 0.90+/-0.25, P = 0.0005) and in LV filling time (from 0.33+/-0.05 to 0.40+/-0.06s, P = 0.0005), followed by a significant progressive reduction in ANP and c-GMP levels. An AVI of 100 ms or 150 ms was associated with improved diastolic indices and lower natriuretic peptides levels, compared with the longer AVI. CONCLUSION: Programmed AVI during DDD pacing affects LV diastolic performance and plasma ANP and c-GMP levels. The assessment of these parameters constitutes a useful modality for AVI optimization.