Copyright © 1988 by the European Society of Cardiology.
© 1988 The European Society of Cardiology
Impaired vagal heart rate control in aortic valve stenosis
Cardiovascular Division, Department of Medicine, Oùlu University Central Hospital Oulu, Finland
Received 23 February 1988; revised 3 May 1988; .
Address for correspondence: K. E. Juhani Airaksinen, M.D., Cardiovascular Division, Department of Medicine, Oulu University Central Hospital, SF-90220 Oulu, Finland. Phone 358-81-252011/3551.
Abstract
Impaired reflex control of heart rate seems to be associated with increased risk of sudden cardiac death. To assess the effect of aortic valve stenosis on parasympathetic heart rate control we measured the heart rate responses to deep breathing and to standing up, non-invasive measures of cardiac parasympathetic activity, in 24 patients with valvular aortic stenosis and in 24 healthy asymptomatic subjects of the same age group. All but one of the patients were symptomatic and the mean aortic valve pressure gradients ranged from 32 to 114 mmHg. The heart rate response to deep breathing was significantly (P >0.05) lower in valve patients than in the healthy subjects. The heart rate changes evoked by standing up, however, did not differ significantly between the groups. The heart rate response to deep breathing was inversely weakly related to the left ventricular end-diastolic pressure (r = 0.41, P > 0.05), but not significantly to the aortic valve pressure gradient, valve area, left ventricular ejection fraction or presence of coronary artery disease.
Our results suggest that the impairment of reflex heart rate control is common in patients with significant aortic valve stenosis.
Key Words: Aortic stenosis autonomic nervous function heart rate sudden death