Harold Sandler

The use of biplane angiocardiography for the measurement of left ventricular volume in man

Abstract 1. 1. A method for correcting distortion due to nonparallel x-rays, as applied to biplane angiocardiography, is described. 2. 2. Five methods for calculating left ventricular chamber volumes from biplane x-rays are described and evaluated by clay models and observations on 9 postmortem hearts in which the left ventricular chambers were distended with known volumes of contrast material. 3. 3. The relation of calculated to known left ventricular chamber volumes for these five methods is presented. 4. 4. These methods provide a basis for calculating the volume of the opacified left ventricular chamber as visualized by biplane angiocardiography.

The use of single plane angiocardiograms for the calculation of left ventricular volume in man.

Abstract A method has been presented for calculating LVV from films taken in a single (A-P) plane projection. This method is based on the assumption that the LV chamber can be represented by an ellipsoid of revolution (prolate spheroid) reference figure. LV volumes were calculated from measurements made on biplane films taken in the A-P and left lateral chest projections. The biplane studies demonstrated that the A-P and lateral diameters of the ventricular chamber were very closely related. Volumes calculated from measurements made only on A-P films closely agreed with biplane calculations of volume. The use of single plane techniques did not result in significant errors for the calculation of absolute end-systolic volume or for calculation of stroke volume.

Usefulness and limitations of radiographic methods for determining left ventricular volume

Abstract The various methods currently being used to determine left ventricular chamber volumes from biplane angiocardiograms are described and discussed. The spatial direction and change of direction and length of the long axis of the left ventricle over the heart cycle is described. The long axis of the left ventricle is in most subjects directed approximately 20 degrees from being parallel with the frontal plane of the body and results in only slight foreshortening of the long axis of the left ventricle on films taken in the anteroposterior projection. A method is described and evaluated for determining left ventricular chamber volume from angiocardiograms taken in a single anteroposterior projection. Values for normal end-diastolic volume and systolic ejection fraction obtained by various investigators using the radiographic methods are given. The application of these radiographic methods to estimate aortic and mitral valve regurgitant flow is reviewed. Pressure-volu ne relations of the diastolic left ventricle have been determined in 176 patients and demonstrate large patient-to-patient differences of ventricular distensibility in patients with different types and durations of heart disease. Measurement of compliance of the diastolic left ventricle from the pressure-volume curves is discussed. By relating pressure and volume curves over the entire heart cycle, left ventricular pressure-volume curves can be constructed and from these the various components of pressure-volume work determined: systolic work, work done in distending the ventricle during diastole, and net work. Values obtained for these various components of ventricular work in patients with heart and valvular disease are discussed. A method for calculating wall tension and stress from measurement of chamber pressure and chamber dimensions is reviewed. Left ventricular mass can be calculated from chamber dimensions and wall thickness determined from angiocardiograms. A value of 92 ± 16 gm. has been obtained by this method in patients without left ventricular disease, and this is similar to values obtained in earlier postmortem studies. Measurement of left ventricular oxygen consumption and mechanical efficiency in patients with heart disease is discussed.

Left Ventricular Tension and Stress in Man

A method is described for calculating tension and stress acting within the wall of the left ventricle during the cardiac cycle. This method is based upon ventricular pressure observations and measurements of left ventricular dimensions and wall thickness made from biplane angiocardiograms. To calculate wall tension and stress, it is assumed that the left ventricle can be represented as an ellipsoid of revolution with a relatively thin wall. The relative importance of ventricular pressure, volume, shape and wall thickness in determining the magnitude of wall tension and stress is illustrated and discussed.

Quantitation of valvular insufficiency in man by angiocardiography.

Abstract A method is described for quantifying aortic and/or mitral valvular regurgitant flow. This method is based on a comparison of left ventricular stroke volume and forward flow per stroke. Left ventricular stroke volume is determined from biplane angiocardiograms. Cardiac output, determined by the Fick or indicator-dilution method, is used as a measure of forward flow. These techniques were applied to study 37 patients with valvular heart disease. Regurgitant flow values of three to four times forward flow were found in subjects with severe valvular insufficiency. In 15 subjects, aortic or mitral valve orifice sizes as calculated from these data agreed closely with findings at operation or postmortem examination.

An Angiocardiographic Method for Directly Determining Left Ventricular Stroke Volume in Man

A method has been described for directly determining left ventricular stroke volume in man through the use of biplane angiocardiography. Left ventricular stroke volume determined by this method has been compared with stroke volumes determined by the Fick and/or indicator-dilution methods in 14 subjects without arrhythmias or clinical evidence of valvular insufficiency. Stroke volumes determined by these various methods showed close agreement.

Cardiovascular effects of isoproterenol in normal subjects and subjects with congestive heart failure

Abstract The cardiovascular effects of isoproterenol administered intravenously at rates of 1 to 2 gamma per minute for periods of 15 to 60 minutes were studied in 3 subjects with essentially normal heart function and 18 subjects with congestive heart failure of varying etiologies. During infusion of the drug, cardiac output and ventricular work invariably increased, stroke volume and ventricular stroke work usually increased, whereas peripheral venous pressure, peripheral vascular resistance, and arteriovenous oxygen difference decreased. Mean pulmonary arterial and systemic arterial pressures remained unchanged or showed a slight increase or decrease. Body oxygen consumption and heart rate rose moderately. These observations indicate that this drug increases the strength of myocardial contraction in both normal subjects and subjects with heart failure.

Left Ventricular Volumes in Valvular Heart Disease

Left ventricular volumes were determined in 86 patients with aortic and mitral valve disease by use of a biplane angiocardiographic technicin conjunction with cardiac catheterization. Total stroke output of the left ventricle was grossly increased by severe degrees of valvular incompetence. Although both end-systolic and total stroke volume varied directly with the end-diastolic volume, there was no correlation between end-diastolic pressure and either total stroke volume or end-diastolic volume.

A Quantitative Angiocardiographic Study of Left Ventricular Hypertrophy and the Electrocardiogram

The QRS amplitude, duration, and mean axis direction of the standard 12-lead electrocardiogram were compared with left ventricular mass, volume, wall thickness, and stroke work in 112 adult patients. These patients had normal left ventricles or various degrees of left ventricular dilatation or hypertrophy. Left ventricular volumes and mass were determined by a quantitative angiocardiographic method. A significant but not a close correlation between left ventricular mass and ECG voltage was found. Enddiastolic volume, stroke volume, stroke work, wall thickness, and “total left ventricular volume” (volume of left ventricular muscle and cavity at end-diastole) had generally lesser degrees of correlation with the QRS amplitude than did the mass alone. Subgrouping of patients into those with pressure overload on the left ventricle, volume overload, aortic valve disease, or anatomic left ventricular hypertrophy did not improve correlations. The left ventricular hypertrophy voltage criteria of Sokolow and of Grant were assessed; respectively, 68% and 67% of 75 patients with anatomic hypertrophy had hypervoltage. The direction of the anatomic long axis of the left ventricle was not significantly related to the mean QRS-vector direction.

Effects of isoproterenol on cardiac output and renal function in congestive heart failure

Abstract The cardiovascular-renal effects of isoproterenol were studied in 12 male subjects with congestive heart failure due to heart disease of varied etiologies. Unlike the majority of sympathomimetic amines, isoproterenol increases renal and systemic blood flow and reduces renal and peripheral vascular resistance. Although effective renal plasma flow increased in all subjects, no significant change in glomerular filtration rate, or consistent change in the flow of urine was observed during infusion of isoproterenol. The excretion of filtered sodium during infusion of the drug increased in 7 of 8 subjects.