Cardiovascular Hemodynamic Functions in Complete Heart Block and the Effect of Isopropylnorepinephrine

Abstract

In 8 patients with complete heart block, cardiac and hemuodynammic functions were determined by methods based on cardiac catheterization. The data characterize the impairment in these functions in asymptomatic subjects and indicate, in addition, the further changes over the course of several years in the same subject, the deleterious effects associated with congestive heart failure, and the changes toward normal induced by isopropylnorepinephrine, a symaipathomiimetic amine known to stimulate the heart and increase ventricular rate in heart block.THE purpose of this report is to present data regarding cardiovascular hemodynamicg functions in patients with established complete heart block.Levinson et al.1 determined cardiovascular dynamics by cardiac catheterization in 5 patients with complete heart block, without congestive heart failure at any time, and reported the following lienodynamnic alterations from the normal: elevated systolic pressure in the right atrium, elevated systolic pressure in the right ventricle and pulmonary artery, increased pulse pressure in pulmonary and systemic arteries, increased stroke volume, and decreased cardiac output. The present study confirms these observations and reports additional information on the following cardiovaseular aspects of complete heart block: changes in cardiovascular dynamics in the same patient over the course of several years, comparison of hemodynamic functions when there is congestive heart failure with the hemodynamic status when heart failure is absent, the hemodynamic effects of isopropylnorepinephrine, a sympathomimetic amine known to increase the ventricular rate in complete heart block.2 Renal hemodynamic functions of 3 of the subjects are also reported.

Response to Exercise in Congenital Complete Atrioventricular Block

“…The present studies were conducted in 11 such patients ranging from 7 to 23 years of age. Diagnosis of congenital A-V block had been made in infancy or early childhood in all patients.…”

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14] There is general agreement that irrespective of the etiology of the block, cardiac enlargement and increased stroke volume are the compensatory mechanisms for the slow rate. In a few studies ventricular rate and other hemodynamic changes have been followed during exercise.1-3' [13][14][15] The prevailing opinion is that in patients with the congenital form of complete heart block the ventricular rate increases more readily than in patients with the acquired form of the arrhythmia.…”

Is sinus bradycardia a factor facilitating overt heart failure?

“…Complete atrioventricular block is commonly reported as a precipitating cause of heart failure; however, it must be underlined that the haemodynamics of complete atrioventricular block are different from those of sinus bradycardia. In fact, this block is characterized, besides slow ventricular rate, by asynchronous atrioventricular contraction, responsible for a rise in mean right and left atrial pressures [13,14] .…”

Cardiovascular Dynamics in Man During Idioventricular Rhythm and at Various, Electrically Determined, Ventricular Rates in, Acquired Complete Heart Block at Rest

“…[19], and also generally elevated in the series by Stack ct al. [20] and Benchimol ct al. [3], but were normal in our series as well as in the 2 cases by Bevegard [2].…”