Physiologic Changes during Chronic Congestive Heart Failure in Dogs with Tricuspid Insufficiency and Pulmonic Stenosis

Abstract

chronic congestive heart failure was studied in dogs with surgically-produced tricuspid insufficiency and pulmonic stenosis. Ascites formed in association with an elevation in mean right atrial pressure. The volume of ascitic fluid and the rate of urinary sodium excretion varied greatly in individual dogs during the course of congestive failure and among the different animals. Sodium retention was most common but periods of sodium balance and natriuresis occurred. Comparative data on the right and left ventricles were obtained from determinations of intracardiac pressures, measurements of ventricular muscle mass at the time of sacrifice and studies of the lungs for evidence of chronic passive congestion. There was significant right ventricular hypertrophy but no evidence of left ventricular hypertrophy or failure.

Chemical Characterization of Cardiac Myosin From Normal Dogs and From Dogs With Chronic Congestive Heart Failure

“…The filling pressures in both the right and the left heart were elevated. The heart was massively enlarged and weighed 502 g. The lungs weighed almost 2.5 times the average normal value of 9.15 + 1.30 g per kg (13) and showed microscopic evidence of chronic passive congestion. The liver showed evidence histologically of chronic congestion and presented the characteristic nutmeg appearance grossly.…”

“…The techniques used for the surgical procedures have been described previously (11)(12)(13). On the day of sacrifice, studies were conducted to determine the physiological state of the animals.…”

“…On the day of sacrifice, studies were conducted to determine the physiological state of the animals. All measurements of cardiovascular pressures were made in trained unanesthetized dogs; the methods have been described previously (13). The methods for Na balance measurements are described elsewhere (1 1, 12); Na intake was 60 mEq per day.…”

“…The right and left ventricular walls were separated from the septum. Since only rightsided heart failure was present in dogs with tricuspid insufficiency and pulmonic stenosis (13), muscle from the right and from the left ventricles of these dogs was extracted separately for myosin. The left ventricle only was used for preparation of myosin from the one dog with naturally occurring right-and left-sided cardiac failure and from the dogs with constriction of the thoracic inferior vena cava.…”

The amino acid composition of actin and myosin and Ca2+-activated myosin adenosine triphosphatase in chronic canine congestive heart failure.

“…Since the experimental heart failure model of Barger et al" has been well characterized, 14 no weight measurements were taken and the preparation of proteins was started as rapidly as possible. Every heart was inspected and right ventricular hypertrophy and dilation were readily apparent in the failing hearts.…”