Comparison of the Left Ventricular, Aortic and Brachial Arterial First Derivative

Abstract

The maximal rate of rise of the left ventricular pressure is now commonly determined in many catheterization laboratories and has achieved wide use as a relatively simple index of contractility.~ 1 Further, there is a highly suggestive correlation between the intensity of the first heart sound and the speed of left ventricular contraCtion.2, 3Gleason and Braunwald' have stressed that the Telco intracardiac manometer should be used to determine the left ventricular dpldt, because of its high frequency response, and in order to avoid the frequent artifacts related to motion of the catheter within the heart. We have found that this instrument will produce excellent recordings, but the extremely high replacement cost of the catheter limits its use. The catheter manometer system usually used in cardiac catheterization can also be used to obtain excellent recordings, if care is taken in placing the catheter in the left ventricular chamber, so that it is reasonably free of motion.A study of the first derivative of the left ventricle, aorta and brachial artery, in patients undergoing diagnostic cardiac catheterization, was undertaken in order to compare these different parameters and to determine their usefulness. METHODSForty-seven patients underwent diagnostic right and left heart catheterizations. Rheumatic heart disease was present in most of the patients studied. Four patients were investigated for benign murmurs and were subsequently found to be free of any cardiac abnormality.Catheterization of the left ventricle was performed either by the Seldinger technique or by retrograde catheterization through a brachial arteriotomy. The rate of change (dpldt) of the left ventricular pressure and the aortic pressure was recorded through a catheter manometer system utilizing a RC differentiating circuit. Measurements were made only when the pressure curves showed an undistorted wave form. A Cournand needle was placed into the opposite brachial artery. For high-fidelity tracings, the needle was directly connected to a Statham P23Db pressure transducer. The first derivative of the brachial artery pressure could then be computed by a RC differentiating circuit. RESULTSComplete data on all 47 patients are presented in table 1. The rate of rise of the left ventricular pressure in the 4 normal patients was from 1615 to

Accurate blood pressure measurement

“…respectively. This left 13 studies, 11, 14-16, 22, 71, 150-153 22 studies, 10,11,14,16,19,68,69,152,[154][155][156][157][158][159][160][161][162][163][164] and 39 studies 11,12,14,16,69,114,118,149,152, for SBP analysis, whereas 12 studies, 11,15,16,22,71,[150][151][152][153] 18 studies, 10,11,16,19,68,69,152,[155][156][157][158][159][160][161][162] and 3...…”