Non-invasive assessment of left ventricular response to Valsalva manoeuvre in normal and diabetic subjects using praecordial accelerocardiography.

Abstract

SUMMARYThe left ventricular response to the Valsalva manoeuvre was studied in 5 normal subjects (group 1), 6 diabetics without autonomic neuropathy (group 2), and 5 diabetics with autonomic neuropathy (group 3), using the maximum amplitude of the praecordial accelerocardiogram (DE) as a noninvasive index of left ventricular performance.During the Valsalva manoeuvre DE decreased in all 3 groups. In groups 1 and 2, DE increased significantly above the control value after release of the manoeuvre (DE overshoot) but this did not occur in group 3. It is suggested that the overshoot of DE in groups 1 and 2 reflects an increase in left ventricular contractility after release of the Valsalva manoeuvre and the absence of an overshoot in DE in the patients with autonomic neuropathy is the result of loss of cardiac adrenergic innervation.The ability to detect an abnormal cardiovascular response to the Valsalva manoeuvre using the non-invasive technique of praecordial accelerocardiography may be of practical value in the assessment of left ventricular function.

Assessment of beat to beat changes in cardiac output during the Valsalva manoeuvre using electrical bioimpedance cardiography

“…Non-invasive studies using two-dimensional echocardiography [3] and praecordial accelerocardiography [2] have concentrated on changes in left ventricular function during Valsalva's manoeuvre rather than CO. We are aware of a previous study which used Kubicek's method, thoracic electrical bioimpedance cardiography, during Valsalva's manoeuvre [ 181. However, data were pre-sented only at 5 , 10 and 15 s during the strain and no data were presented from the post strain period.…”

“…The present investigation was undertaken to determine (1) whether analysis of changes in thoracic electrical bioimpedance can be used to determine beat to beat changes in CO during Valsalva's manoeuvre, and (2) to characterize the profile of these changes in a small group of normal individuals.…”