Albert J. Libanoff

Atrioventricular Pressure Half-Time Measure of Mitral Valve Orifice Area

In 20 patients studied by cardiac catheterization, the time required for the diastolic left atrioventricular pressure difference to fall to half its initial value (half-time) varied with the anatomic severity of the valvular stenosis. In mild mitral stenosis, the half-time was approximately 100 msec; in moderate stenosis, it was about 200 msec; and it was 300 msec or longer in severe stenosis. The half-time at the nonstenotic mitral valve was less than 25 msec.Although exercise increased the atrioventricular pressure gradient, heart rate, and cardiac output significantly, the half-time was affected only slightly. Mitral regurgitation of various severities did not affect the half-time. The half-time appears to vary inversely with the anatomic orifice area of the mitral valve. The determination of the half-time obviates the need for the commonly used exercise test for the evaluation of mitral stenosis.

Evaluation of the Severity of Mitral Stenosis and Regurgitation

Indices have been developed that provide an improved means for evaluation of the degrees of severity of mitral stenosis and regurgitation. The severity of anatomic mitral valve disease found at surgery or autopsy was considered to be the determinant of the state of the valve. An index of the time for the diastolic atrioventricular pressure gradient to fall to half its value multiplied by 100 and divided by the cardiac index was shown to be comparable to the severity of anatomic stenosis. This index ranged from 5.7 to 10 in mitral stenosis, 0.4 to 0.8 in normal subjects, and 0.6 to 2.0 in patients with predominant mitral regurgitation.Mitral regurgitation was estimated by an index of the rate of the atrial pressure rise during ventricular systole in mm. Hg/0.02 second multiplied by 10, and divided by the cardiac index. In predominant mitral regurgitation, this index ranged from 8.0 to 15; in mitral stenosis these values were 3.7 to 6.3, and normal subjects had an index varying from 2.5 to 3.7.Both indices were significantly elevated in patients in whom stenosis and regurgitation were present at surgery. Mitral stenosis complicated by a mild degree of regurgitation gave significantly elevated stenotic indices, while the regurgitation indices were normal or slightly elevated. These indices facilitate the evaluation of either mitral stenosis or regurgitation even when both processes are present together.The significance of these indices in the evaluation of the degree of invalidism in patients with valvular disease is also discussed.

Differentiation of Aortic-Valve Stenosis from Subaortic Muscular Stenosis by Means of Arterial-Sound Recordings

THE clinical methods of history and physical examination and laboratory findings such as x-ray study and electrocardiography often prove inadequate for the differentiation of stenosis of the aortic...

DIAPHRAGMATIC MYOCARDIAL INFARCTION WITH PERI-INFARCTION BLOCK. STUDIES OF THE ELECTROCARDIOGRAM AND VECTORCARDIOGRAM.

Abstract Presented here are the vectorcardiograms and electrocardiograms of 10 normal patients, 12 with diaphragmatic infarction, 15 with diaphragmatic infarction and diaphragmatic peninfarction block, 3 with right bundle branch block, and 4 with diaphragmatic infarction plus right bundle branch block. The characteristics of the electric patterns of diaphragmatic infarction with diaphragmatic peri-infarction block are: 1. (1) Diaphragmatic infarction changed the initial QRS vector, pointing it away from the site of infarction (diaphragm). Orientation was leftward, superiorly and anteriorly. 2. (2) In diaphragmatic peri-infarction block, the terminal QRS vector was altered and directed toward the site of infarction (diaphragm) and oriented to the right, posteriorly, and inferiorly or superiorly. 3. (3) In the electrocardiogram, QRS prolongation greater than 0.10 sec. seldom occurred. However, the vectorcardiogram always showed terminal 0.03 sec. QRS loop slowing. In peri-infarction block, the terminal vector was slowed and in the right, posterior quadrant; in right bundle branch block, terminal depolarization was again slowed but located in the right, anterior quadrant. The depolarization delay in peri-infarction block, seen only by vectorcardiogram, may be due to abnormal repolarization with early repolarization potentials altering and delaying the apparent terminal depolarization vector. How the tracings of peri-infarction block and right bundle branch block differed from the normal and from diaphragmatic infarction without block is illustrated and discussed.

Primary Pulmonary Hypertension: Familial Incidence:

In spite of great recent advances in the fields of cardiac, pulmonary and vascular disease, the basic etiology of vascular hypertension remains obscure. This is true of pulmonary hypertension as well as of its counterpart, systemic hypertension. In many instances, factors known to increase the vascular tone are present. Typical examples are those from increased blood flow produced by intracardiac shunts, increased pulmonary vascular resistance created by disease of the left heart, and the effects of certain diseases of the kidney on systemic circulation. However, the pathophysiology underlying the vascular reaction in these conditions is not yet completely understood.

A Hemodynamic Measure of Aortic Regurgitation

Cardiac catheterization findings were used in 50 patients to determine the degree of aortic regurgitation from pressure recordings in the ascending aorta. The time needed for aortic pressure to drop t

Clinical studyDiaphragmatic myocardial infarction with peri-infarction block: Studies of the electrocardiogram and vectorcardiogram

Abstract Presented here are the vectorcardiograms and electrocardiograms of 10 normal patients, 12 with diaphragmatic infarction, 15 with diaphragmatic infarction and diaphragmatic peninfarction block, 3 with right bundle branch block, and 4 with diaphragmatic infarction plus right bundle branch block. The characteristics of the electric patterns of diaphragmatic infarction with diaphragmatic peri-infarction block are: 1. (1) Diaphragmatic infarction changed the initial QRS vector, pointing it away from the site of infarction (diaphragm). Orientation was leftward, superiorly and anteriorly. 2. (2) In diaphragmatic peri-infarction block, the terminal QRS vector was altered and directed toward the site of infarction (diaphragm) and oriented to the right, posteriorly, and inferiorly or superiorly. 3. (3) In the electrocardiogram, QRS prolongation greater than 0.10 sec. seldom occurred. However, the vectorcardiogram always showed terminal 0.03 sec. QRS loop slowing. In peri-infarction block, the terminal vector was slowed and in the right, posterior quadrant; in right bundle branch block, terminal depolarization was again slowed but located in the right, anterior quadrant. The depolarization delay in peri-infarction block, seen only by vectorcardiogram, may be due to abnormal repolarization with early repolarization potentials altering and delaying the apparent terminal depolarization vector. How the tracings of peri-infarction block and right bundle branch block differed from the normal and from diaphragmatic infarction without block is illustrated and discussed.

Eosinophilia and endomyocardial fibrosis

A 12 year old boy died after a 3 year course of recurrent and progressive heart failure. His cardiac symptoms began with a marked leukocytosis (white blood cell count 188,500/mm3) due to eosinophilia (90 percent). In 6 months, the leukocytosis and eosinophilia subsided, but the patients heart failure progressed over the next 2 1/2 years. At autopsy there was no evidence of leukemia, but a severe endocardial fibrosis extending into the myocardium was found. The origin of endomyocardial fibrosis, although unknown, appears to have been related to the eosinophilia in this patient.

Upstroke time ratio in valvular aortic insufficiency

Abstract The upstroke time ratio has been studied in 15 normal controls and in 31 patients with pure aortic regurgitation and varying stages of myocardial involvement. The upstroke time ratio results were as follows: 15 normal subjects, 0.50 to 0.70; 31 patients with rheumatic aortic valvular insufficiency, of whom 9 had cardiac decompensation, 0.50 to 0.80; and 22 with no evidence of myocardial failure, 0.31 to 0.50. These patients were graded from 0 to IV, depending upon the degree of aortic regurgitation by the Braunwald method. Those with lower ratio had grade III and IV regurgitant index and were found to have good myocardial reserve. Others with grade III and IV and elevated ratio were classified as having poor myocardial reserve, and should be high surgical risks if open heart surgery is performed. The upstroke time ratio is an indirect measurement of aortic valvular regurgitation and is a useful index in evaluating secondary myocardial involvement.

Hemodynamic findings before and after occurrence of a left ventricular-right atrial fistula

Abstract A patient who had a left ventricular-right atrial fistula, produced at heart surgery, is described. This occurred when the medial leaflet of the tricuspid valve was used in an attempt to close an intraventricular septal defect. A residual shunt remained, producing a fistula. Pressure changes occurred which were characterized by an elevated right atrial maximum and elevated mid-diastolic and end-diastolic right ventricular components. In the presence of left to right shunting at the atrial level, with these characteristic right atrial and right ventricular pressures, the diagnosis of left ventricular-right atrial fistula should be considered.