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Single versus dual chamber pacing in the young: noninvasive comparative evaluation of cardiac function
M Silvana Horenstein1, Peter P Karpawich, M Victoria T Tantengco
1Division of Cardiology, Department of Pediatrics, Children's Hospital of Michigan, Wayne State University School of Medicine, Detroit, Michigan 48201, USA.
Insights
Atrial synchrony via dual-chamber pacing offers no early cardiac function benefits in young patients with complete AV block compared to single-chamber right ventricular pacing. Early conversion may not be necessary for asymptomatic individuals with normal ventricular function.
Area of Science:
- Cardiology
- Biomedical Engineering
- Clinical Electrophysiology
Background:
- The benefits of atrial synchrony in young patients with chronic right ventricular (RV) pacing are not well-established.
- Older patients with diastolic dysfunction benefit from dual-chamber pacing (DDD,R/VDD) over single-chamber pacing (VVI,R).
Purpose of the Study:
- To noninvasively assess cardiac function in young, RV-paced patients before and after establishing atrial synchrony.
Main Methods:
- Retrospective analysis of echocardiographic data from 10 patients with complete AV block.
- Comparison of left ventricular (LV) systolic and diastolic function during VVI,R pacing versus DDD,R/VDD pacing.
Main Results:
- No significant short-term difference in LV systolic function (fractional area of change) was observed.
- No significant short-term difference in diastolic function (mitral E velocity normalized to VTI) was found.
- A decrease in mitral flow E/A ratio was noted after short-term DDD,R/VDD pacing.
Conclusions:
- Atrial synchronous dual-chamber pacing does not induce early changes in global LV function in young patients with complete AV block compared to RV pacing.
- Early establishment of atrial synchrony may not be warranted in young, asymptomatic VVI,R-paced patients with normal intrinsic ventricular function.
Abstract:
The advantages of atrial synchrony over asynchronous ventricular pacing remain unclear in the young, chronically right ventricular (RV) - paced patient. This is in contrast to the older patient with inherent diastolic dysfunction who has been shown to benefit from atrial synchrony with dual chamber (DDD,R/VDD), over single chamber rate response (VVI,R) ventricular pacing. The goal of this study was to noninvasively assess cardiac function in a group of young, RV-paced patients before and after establishment of atrial synchrony. Echocardiographic data were retrospectively analyzed from 10 patients with congenital or acquired complete AV block, who were VVI,R paced for 10.2 +/- 2 years (mean age at study 19.2 +/- 8.9 years), and were subsequently converted to DDD,R/VDD pacing (mean age at study 20.7 +/- 9.5 years). Paired t-test analysis of left ventricular (LV) systolic and diastolic function during VVI,R versus DDD,R/VDD pacing did not result in any short-term difference in LV short axis fractional area of change or FAC (53% +/- 7.5% vs 56.8% +/- 8.7%) or mitral maximal velocity (E) normalized to mitral flow velocity time integral (VTI) (5.2/s +/- 1.5 vs 4.4/s +/- 1.5). A decrease in mitral flow E/A ratio was observed after short-term DDD,R/VDD pacing (2.2 +/- 0.5 vs 1.9 +/- 0.3). Atrial synchronous dual chamber pacing in young patients with complete AV block does not lead to any appreciable early change in global LV function over single-site RV pacing. Therefore, early establishment of atrial synchrony in the young asymptomatic VVI,R-paced patient with normal intrinsic ventricular function may not be warranted.