In:
Cardiology, S. Karger AG, Vol. 111, No. 1 ( 2008), p. 68-74
Abstract:
〈 i 〉 Objectives: 〈 /i 〉 There is still little information about the cardiorespiratory effects of cardiac resynchronization therapy (CRT) in patients undergoing all-day physical activity. This study aimed to assess the effects of CRT on ventilatory perfusion coupling during submaximal exercise. 〈 i 〉 Methods: 〈 /i 〉 Metabolic and hemodynamic parameters were obtained during treadmill exercise testing as well as during rest for each single-right (RV), -left (LV) and biventricular (BiV) pacing mode as well as during intrinsic conduction (VVI 30) in 37 patients. Only responders to CRT ( 〉 10% increase in cardiac output (CO) during BiV pacing; n = 27) were included into the evaluation. 〈 i 〉 Results: 〈 /i 〉 LV and BiV pacing increased systolic (144 ± 25 and 142 ± 28 vs. 118 ± 29 mm Hg, p 〈 0.05) and mean blood pressure (108 ± 19 and 109 ± 19 vs. 94 ± 25 mm Hg, p 〈 0.05) as well as CO (7.0 ± 0.6 and 7.2 ± 0.8 vs. 6.0 ± 0.6 l/min, p 〈 0.05 and p 〈 0.01) during exercise as compared to VVI 30. Simultaneously, LV and BiV pacing decreased dead space ventilation (18 ± 3 and 17 ± 3 vs. 20 ± 4, p 〈 0.01) and the ventilatory equivalent for oxygen (31 ± 4 and 31 ± 5 vs. 36 ± 6; p 〈 0.05) compared to intrinsic conduction. 〈 i 〉 Conclusion: 〈 /i 〉 The improvement in ventilatory efficacy during CRT, which is demonstrated by the decrease in the ventilatory equivalent for oxygen, results from an increase in CO and thus from a reduction in the ventilatory perfusion mismatch.
Type of Medium:
Online Resource
ISSN:
0008-6312
,
1421-9751
Language:
English
Publisher:
S. Karger AG
Publication Date:
2008
detail.hit.zdb_id:
1482041-9
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