BASIC RESEARCH on the ventricular pressure-volume loop diagram has been revived.' Several investigators2-8 proposed that the relationship of end-systolic pressure (or wall stress) to end-systolic volume (or some dimension) may be useful in evaluating the contractile state of the heart. Grossman et al. published an important clinical study\" in 1977; many others followed. At the 1980 annual meetings of the American Heart Association and American College of Cardiology, at least 11 papers0-21 were presented concerning the end-systolic relationship between pressure and volume, pressure and thickness, and wall stress and normalized volume. Several significant studies2' 39 have also appeared in the past 5 years; a dozen clinical studies have been published. With this popularity, the original meanings of end-systolic pressure-volume relation and its parameters (e.g., Emax, m, V0 and Vd) have become ambiguous. Sometimes they were purposely modified to attempt to improve their value and other times just to make the measurement easy. Whatever the reasons, it seems appropriate to review these modifications with reference to the proponents' original ideas about fundamental aspects.

The end-systolic pressure-volume relation of the ventricle: definition, modifications and clinical use.

The Relationship Between the Right Ventricle and its Load in Pulmonary Hypertension.

Diltiazem is an orally and intravenously active calcium channel blocking agent shown to be an effective and well-tolerated treatment for stable angina and angina due to coronary artery spasm Its efficacy in these diseases has generally been similar to that of nifedipine or verapamil - alternative calcium channel blockers with which diltiazem has many electrophysiological, haemodynamic, and antiarrhythmic similarities The antianginal mechanism of diltiazem cannot be precisely described; however, it appears to increase myocardial oxygen supply and decrease myocardial oxygen demand, mainly by coronary artery dilatation and/or via both direct and indirect haemodynamic alterations Diltiazem has also shown substantial efficacy in the treatment of unstable angina, hypertension, and supraventricular tachyarrhythmias, but further study is necessary before its place in the treatment of these diseases may be clearly established Although headache due to peripheral vasodilatation and depression of atrioventricular nodal conduction may be troublesome, side effects occur in only 2 to 10% of patients receiving diltiazem and are generally minor in nature Thus, diltiazem offers a worthwhile alternative to other agents currently available for the treatment of angina pectoris Although the infrequency of serious side effects may offer an advantage, its relative place in therapy compared with that of other calcium channel blockers remains to be clarified

Diltiazem. A review of its pharmacological properties and therapeutic efficacy.

Background The end-systolic pressure-volume relation (ESPVR) provides a useful measure of contractile function. However, the need to acquire multiple cardiac cycles at varying loads limits its applicability. We therefore developed and tested a novel single-beat estimation method that is based on normalized human time-varying elastance curves [EN(tN)]. Methods and Results Pressure-volume (PV) data were measured by conductance catheter in 87 patients with normal or myopathic hearts. Time-varying elastance curves were generated from 72 PV loops (52 patients) and normalized both by amplitude and time to peak amplitude. The resulting EN(tN) curves were remarkably consistent despite variations in underlying cardiac disease, contractility, loading, and heart rate, with minimal interloop variance during the first 25% to 35% of contraction. On the basis of this finding and assuming ESPVR linearity and constant volume-intercept, ESPVRs were estimated from one beat with the use of PV data measured at normalized time...

Single-Beat Estimation of End-Systolic Pressure-Volume Relation in Humans A New Method With the Potential for Noninvasive Application

Assessement of right ventricular (RV) contractility from end-systolic pressure-volume relationships (ESPVR) is difficult due to problems in measuring RV instantaneous volume and to effects of chang...

https://www.physiology.org/doi/pdf/10.1152/ajpheart.01023.2002

Single-beat estimation of right ventricular end-systolic pressure-volume relationship

The relationship between peak isovolumic developed pressure (Pmax) and end-diastolic volume can indicate ventricular contractility. Therefore, we propose a practical method to estimate Pmax from the pressure curve of an ejecting contraction of left ventricle. For the estimation, we first considered the left ventricle a linear time varying hydromotive pressure source (HMP(t)) coupled in series with an internal impedance. To formulate the HMP(t) we Fourier analyzed isovolumic pressure curves obtained under various conditions in six dogs. Since the higher order harmonics were found to be very small, HMP(t) could be described simply as where Pd = end-diastolic pressure and w = 2/T in which T is duration of contraction. Finally, HMP(t) for ejecting contraction was estimated by fitting the equation to the isovolumic portions of the pressure curve of ejecting contractions. The estimated Pmax values correlated well with actually observed Pmax values (r = 0.951, N = 24). We conclude that the proposed technique can be used to estimate Pmax from a single ejecting beat.

Estimation of the Hydromotive Source Pressure from Ejecting Beats of the Left Ventricle

Myocardial blood flow following experimental coronary occlusion. Effects of diltiazem.

• We encountered a case of right internal mammary artery to innominate vein fistula following subclavian vein catheterization and the projection of the coil spring was projected after transcatheter intravascular coil occlusion. We were worried about both distal thromboembolism from small thrombi forming on a portion of the coil spring and stenosis of the subclavian artery. However, there was no evidence of thromboembolism of the distal artery, and good patency of the right subclavian artery was shown by an angiogram performed six months later. The patient has been receiving heparin therapy during hemodialysis, which should help prevent thromboembolism of the distal artery. ( Arch Intern Med 1985;145:140-141)

Iatrogenic arteriovenous fistula of the internal mammary artery. Transcatheter intravascular coil occlusion.

Real-time measurement of the spatial magnitude of the St segment with the automated vectorcardiographic ST segment analyzer

To determine the effects of diltiazem, a new calcium antagonist, on myocardial ischemia, two experiments

Yutaka Senda

Papers

Estimation of the Hydromotive Source Pressure from Ejecting Beats of the Left Ventricle

Myocardial blood flow following experimental coronary occlusion. Effects of diltiazem.

Iatrogenic arteriovenous fistula of the internal mammary artery. Transcatheter intravascular coil occlusion.

Real-time measurement of the spatial magnitude of the St segment with the automated vectorcardiographic ST segment analyzer

Myocardial Blood Flow following