Right heart catheterization in rats with pulmonary hypertension and right ventricular hypertrophy

Abstract

Using a special Millar ultraminiature catheter pressure transducer, right ventricular functional parameters were measured in anesthetized, closed-chest rats under control conditions, during acute pulmonary hypertension and after induction of right ventricular hypertrophy. Acute i.v. infusion of noradrenaline and a brief period of hypoxia in female Sprague-Dawley rats elicited a marked increase in right ventricular systolic pressure (RVSP) and in the maximal rate of rise in right ventricular pressure (RV dp/dtmax). After 3 and 16 days of daily administrations of triiodothyronine in female Sprague-Dawley rats, all right ventricular hemodynamic parameters were enhanced along with the increase in left ventricular function. The right and left ventricles were hypertrophied, and cardiac output was increased. After 40 and 45 days subsequent to bilateral thorax irradiation of male Brown-Norway rats, RVSP and RV dp/dtmax were increased, the right ventricle was hypertrophied, while the left ventricle did not exhibit appreciable hemodynamic or morphologic alterations. Cardiac output was depressed. Thus, these two experimental models differ considerably as to the mechanism and time course of the development of right ventricular hypertrophy as well as to the participation of the left ventricle and the involvement of volume overload.

Catheterization of pulmonary artery in rats with an ultraminiature catheter pressure transducer

“…Also, RVSP was elevated in this rat strain, although not to the same extent as previously observed in SpragueDawley rats (24). The stimulation intervals with NE, however, were longer in most of the studies in which NE had been shown to elevate RVSP (1,8).…”

“…The catheter must be directed from the jugular vein and the right atrium into the right ventricle, a procedure that was established previously (24). When the catheter is placed in the right ventricle, the catheter tip has to follow the blood stream, i.e., a diversion from the direction of inflow, that ultimately passes the pulmonary valve in an antegrade fashion.…”

“…Also, the method for catheterization of the left ventricle in rats using ultraminiature catheter pressure transducers was established earlier (21) than that for catheterization of the right ventricle (24). Recently, catheterization of both heart chambers with microtip catheters has become feasible also in mice (3).…”

Remodeling of myocyte dimensions in hypertrophic and atrophic rat hearts.

“…At HT we~ (9) creased, although heart rate was not changed compared with the control value. T3 treatment supports the predominance of the fast V, isomyosin in the rat.…”

Reoxygenation Reverses Hypoxic Pulmonary Arterial Remodeling by Inducing Smooth Muscle Cell Apoptosis via Reactive Oxygen Species–Mediated Mitochondrial Dysfunction

“…A soft catheter linked to a pressure transducer was inserted into the right ventricle through the right external jugular vein. Right ventricle systolic pressure (RVSP), approximately equal to pulmonary arterial pressure,31, 32 was recorded on the monitor of the Powerlab system (AD Instruments, Castle Hill, New South Wales, Australia). Systemic systolic pressure was measured through a catheter inserted into the carotid artery.…”