Sympathetic alternans. Evidence for arterial baroreflex control of muscle sympathetic nerve activity in congestive heart failure
Abstract
Alternation in the amplitude of muscle sympathetic nerve activity (MSNA) was documented in three patients with severe heart failure. In the index patient with pulsus alternans, the amplitude of MSNA was inversely related to changes in the preceding diastolic pressure with a lag time of 1.2 to 1.3 seconds, indicating that oscillations in burst amplitude are determined primarily by changes in this component of blood pressure. Spectral analysis of the blood pressure and MSNA signals identified two spectral peaks, one at the cardiac frequency and a second peak, with greater spectral power, at the alternans frequency (ie, at half the heart rate). The latter peak for both blood pressure and MSNA disappeared when alternans was abolished by nitroglycerin. The presence of sympathetic alternans in synchrony with pulsus alternans and the rapid transduction of changes in the diastolic blood pressure afferent signal to the amplitude of sympathetic outflow indicate that the arterial baroreflex control of MSNA must be active and rapidly responsive in human heart failure.
References
Citations
Related Concepts
Related Feeds
Antianginal Drugs: Mechanisms of Action
Antianginal drugs, including nitrates, beta-blockers, and calcium channel blockers, are used in the treatment of angina pectoris. Here is the latest research on their use and their mechanism of action.
Cardiology Journals
Discover the latest cardiology research in this collection of the top cardiology journals.
Cardiomyopathy
Cardiomyopathy is a disease of the heart muscle, that can lead to muscular or electrical dysfunction of the heart. It is often an irreversible disease that is associated with a poor prognosis. There are different causes and classifications of cardiomyopathies. Here are the latest discoveries pertaining to this disease.