Abstract
AIM: The objective was to evaluate in treated heart failure (HF) patients whether multidrug therapy interferes with the cardiovascular autonomic response to postural stress. METHODS AND RESULTS: Blood pressure (BP; Finapres), heart rate (HR), stroke volume, and total peripheral resistance (TPR) responses to standing up were measured in 33 HF patients and 10 healthy age-matched controls. Ten hypertensive (HT) patients treated with a similar combination of drugs but without heart failure served as reference subjects to account for use of medication. Frequency domain measures of HR and BP variability were calculated as correlates of cardiovascular autonomic function. Postural hypotension was found in 16 out of 33 HF patients independently from New York Heart Association functional class. In HF patients vs. HT patients and healthy controls the haemodynamic postural response was abnormal with a large initial BP fall and a slackened reflex increase in TPR resulting in inadequate BP recovery. HR and BP variability were normal in HT patients and healthy controls but attenuated in HF patients. The magnitude of the postural HR, stroke volume, and TPR responses as well as HR and BP variability was inversely related to the New York Heart Association class. CONCLUSIONS: In HF patients, the autonomic vasomotor response to postural stress is abnormal, more pronounced with increasing disease severity, and frequently associated with overt postural hypotension. These phenomena appear related to the cardiac condition rather than treatment.