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Effects of Chronotropic Responsive Cardiac Pacing on Ventilatory Response to Exercise in Patients with Complete AV Block
Author(s) -
TANI MASANAO,
FUJIKI AKIRA,
ASANOI HIDETSUGU,
YOSHIDA SHIGEKI,
TSUJI HIROSHI,
MIZUMAKI KOICHI,
SASAYAMA SHIGETAKE
Publication year - 1992
Publication title -
pacing and clinical electrophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.686
H-Index - 101
eISSN - 1540-8159
pISSN - 0147-8389
DOI - 10.1111/j.1540-8159.1992.tb02922.x
Subject(s) - medicine , chronotropic , cardiac pacing , cardiology , heart block , anesthesia , heart rate , electrocardiography , blood pressure
To identify the effect of chronotropic responsive cardiac pacing on the ventilatory response to exercise, ten selected patients with complete atrioventricular block underwent paired cardiopulmonary exercise tests in fixed rate ventricular (WI) and dual chamber (DDD) or rate responsive ventricular (VVIR) pacing modes. Compared to VVI pacing, DDD or VVIR pacing increased peak oxygen uptake (P < 0.005) and augmented anaerobic threshold (P < 0.001), In eight patients, dyspnea was the major symptom limiting exercise with VAT pacing and this was markedly attenuated with DDD or VVIR pacing. In all patients, ventilation (VE) and the ratio of ventilation to CO 2 production (VE/VCO 2 ) were consistently higher with VVI pacing during exercise. To compare the response of the two pacing modes at the same workloads in an aerobic condition, we measured ventilatory variables 1 minute prior to the anaerobic threshold obtained with VVI pacing. When DDD or VVIR pacing was compared with VVI pacing, VE and VE/VCO 2 significantly decreased from 20.5 ± 5.3 L/min to 18.3 ± 5.0 L/min (P < 0.005) and from 35.9 ± 5.8 to 31.9 ± 5.0 (P < 0.003), respectively. Respiratory frequency rose significantly more with VVI pacing (P < 0.001) despite an unchanged tidal vohame. Although peak VE did not differ between the two pacing modes, VE/VCO 2 at the peak exercise increased significantly more with VVI pacing (P < 0.005). Respiratory frequency also rose more with VVI pacing (P < 0.005) and tidal volume did not change. This study suggests that chronotropic responsive cardiac pacing attenuates the exertional dyspnea by improving the ventilatory response to exercise as well as increasing the cardiac output in patients with complete atrioventricular block.