bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Coronary Artery Disease and Acute Myocardial Infarction on Left Ventricular Compliance in Man
Authors: DIAMOND GEORGE , FORRESTER JAMES S.
Published: June 2012

The evaluation of left ventricular (LV) compliance by use of the pressure-volume (P-V) relationship encounters several serious difficulties. Since the P-V relationship is curvilinear, it is difficult to quantitate. Furthermore, alterations of resting heart size and geometry also produce marked changes in the P-V curve. The first derivative of the P-V relationship, however, is a precisely linear function expressed by the formula dP/dV = aP+b. The slope of this linear function, a, termed the passive elastic modulus, has been shown to be independent of initial volume and primarily and predominantly determined by changes in the stiffness of the myocardium. Myocardial wall stiffness was evaluated in three groups of subjects during LV catheterization. In 13 normal subjects a = 0.005; in 13 with coronary artery disease a = 0.011; and in 12 with acute infarction a = 0.045. The differences in stiffness among the groups were highly significant (
P
< 0.005).

It was concluded that a measurable change in ventricular compliance occurs with the development of coronary artery disease and that a further increase in wall stiffness occurs with the development of acute infarction. The magnitude of increase in LV wall stiffness correlated directly with immediate prognosis: 87% of those subjects with a ΔP/ΔV greater than 0.5 mm Hg/cc died of power failure during the acute stage of their illness. These alterations in compliance may invalidate certain traditional concepts of LV function and heart failure.
Hemodynamic Evaluation of Left Ventricular Function in Shock Complicating Myocardial Infarction
Authors: RATSHIN ROBERT A. , RACKLEY CHARLES E. , RUSSELL RICHARD O.
Published: June 2012

Twenty-two patients with shock complicating myocardial infarction were studied hemodynamically and, despite pharmacologic therapy and regulation of intravascular volume, 16 (73%) subsequently expired. Pulmonary artery end-diastolic pressure (PAEDP) or left ventricular end-diastolic pressure (LVEDP) was > 15 mm Hg in 18 of the 22 patients, and cardiac index (CI) was ≤2.3 liters/min/m
2
in 17 of 22 patients. Fourteen of the 18 patients with PAEDP or LVEDP > 15 mm Hg expired, while two of the four patients with a PAEDP or LVEDP < 15 mm Hg survived. Thirteen of 15 individuals with a CI < 2.3 liters/min/m
2
died, and four of seven with a CI ≤ 2.3 liters/min/m
2
survived. A ventricular gallop (S
3
) was audible in 15 patients with PAEDP or LVEDP varying from 13 to 60 mm Hg. In 11 patients with an S
3
who expired, the PAEDP or LVEDP ranged from 22 to 60 mm Hg. Mean peripheral vascular resistance was 41.3 units in survivors and 67.8 units in nonsurvivors. Six of eight patients who did not survive the period of hospitalization had a depressed response to dextran infusion manifested by a greater increase in PAEDP or LVEDP than in CI.

Hemodynamic evaluation permitted early identification of measurements associated with 100% mortality despite intensive medical treatment. These findings included: (1) PAEDP or LVEDP > 28 mm Hg and (2) PAEDP or LVEDP > 15 mm Hg in association with a CI < 2.3 liters/min/m
2
. Patients in cardiogenic shock with these hemodynamic alterations are presumably candidates for cardiocirculatory mechanical assisting devices and possibly for further surgical intervention.
Surgical Treatment of Partial Anomalous Pulmonary Venous Drainage
Authors: FRIEDLI B. , GUÉRIN R. , DAVIGNON A. , FOURON J. C. , STANLEY P.
Published: June 2012

Fourteen children who had been operated on for partial anomalous pulmonary venous return from the right lung to the vena cava or right atrium have been submitted to a follow-up study 1 to 9 years after surgery. This included clinical, hemodynamic, and angiographic data. All patients were doing well and had normal exercise tolerance at the time of follow-up examination. Electrocardiograms and chest roentgenograms had returned to normal in 10 and were improved in three. Hemodynamic and angiographic data demonstrated perfect correction in eight. Of the remaining six, three had an obstructed superior vena cava (SVC) with collateral pathways to a persistent left superior vena cava in two and to the inferior vena cava in one. Three had significant pressure gradients between the SVC and the right atrium, two with a small right-to-left shunt from the SVC to the left atrium, and one with an additional small left-to-right shunt. None had obstruction to the pulmonary venous return. These complications occurred exclusively in cases in which at least one anomalous vein drained high into the superior vena cava. Enlargement of the SVC with a patch of pericardium gave good results in three patients with this type of anomalous drainage but did not prevent obstruction or severe narrowing of the SVC in two other cases. It is concluded that the present corrective technics are not adequate for cases in which an anomalous vein drains high in the SVC, especially in the presence of a left superior vena cava.
Fleischner Lines and Pulmonary Emboli
Authors: BARON MURRAY G.
Published: June 2012

Fleischner lines are often the only roentgen evidence of pulmonary embolization, particularly when the emboli are small. The linear shadows are cast by focal areas of atelectasis viewed on end. The atelectasis is an indirect manifestation of the vascular occlusion and is due to obstruction of a subsegmental bronchus by retained secretion or by hemorrhagic exudate. Although Fleischner lines are not seen in every case of pulmonary embolization, when present, and especially when bilateral, they are definitely suggestive of the diagnosis.
Sudden Death Related to Myocardial Infarction
Authors: JAMES THOMAS N.
Published: June 2012

Sudden death as it relates to myocardial infarction (not necessarily acute) is discussed on the premise that most such deaths are due to a lethal electrical disturbance of the heart. The three sections of the first part deal with the rhythm of the heart, conduction in the heart, and neural control of the heart. In these sections consideration is made of those factors which stabilize cardiac electrical performance, and conversely how these factors may be deranged into electrical instability. In the second part a practical discussion is organized to interrelate the principles presented on maintenance and derangement of electrical stability of the heart; the electrical reserve of the heart, some unstabilizing factors, and clinical considerations are the subjects for this integrating synthesis. The entire review is designed to provide the clinical cardiologist a framework of reference in which logical decisions can be made in caring for the patient who has coronary disease and in whom myocardial infarction will be, is, or has been a complication. By a fuller appreciation of principles underlying maintenance of electrical stability of the heart, the risk of dying suddenly from electrical instability may be reduced.
Coronary Arteries in Fatal Acute Myocardial Infarction
Authors: ROBERTS WILLIAM C.
Published: June 2012

The coronary arteries are diffusely involved by atherosclerotic plaques in fatal acute myocardial infarction (AMI). The degree of luminal narrowing may vary but plaques are present in practically every millimeter of extramural coronary artery. Usually the lumens of at least two of the three major coronary arteries are narrowed > 75% by old plaques in patients who die suddenly (< 6 hours) from cardiac disease with or without myocardial necrosis. Coronary thrombi occur in about 10% of patients who die suddenly or in whom necrosis is limited to the left ventricular subendocardium, and in about 50% of patients with transmural myocardial necrosis. Coronary thrombi usually indicate the presence of shock or congestive heart failure or both during the development of myocardial necrosis. The infrequency of coronary thrombi in patients dying suddenly of cardiac disease and in those with transmural necrosis who never have shock or congestive heart failure suggests that the thrombi may be consequences rather than causes of AMI.

Although it may not precipitate AMI, coronary thrombosis may still be the underlying cause of the atherosclerosis. The finding of fibrin deposits in old atherosclerotic plaques and the findings of atherosclerotic-type lesions (cholesterol clefts, foam cells, pultaceous debris, calcific deposits) in organized known thrombi (as in the left atrium in mitral stenosis) suggest a strong relationship between thrombosis and atherosclerosis.

Coronary arterial emboli are not rare; they are located in distal portions of the coronary tree and are present in the small epicardial branches as well as in intramural coronary arteries. In contrast, coronary thrombi are located in proximal portions of major extramural vessels, are infrequent in the small epicardial branches, and are absent in intramural coronary arteries. Coronary atherosclerosis is limited to the extramural coronary arteries and spares the intramural coronary arteries.
Left Ventricular Function in Acute Myocardial Infarction and its Clinical Significance
Authors: RACKLEY CHARLES E. , RUSSELL RICHARD O.
Published: June 2012

Investigations on left ventricular function in patients with acute myocardial infarction and the relatonship to clinical findings have shown: (1) limitations in the use and interpretation of central venous pressure; (2) pulmonary artery end-diastolic pressure accurately reflects left ventricular filling pressure in the absence of pulmonary vascular or mitral valve disease; (3) left ventricular filling pressure is frequently elevated in mild or clinical uncomplicated infarction; (4) left ventricular function frequently improves during the immediate as well as late convalescent period; (5) the hemodynamic and clinical evaluations may frequently be at variance; (6) a left ventricular gallop is usually associated with an abnormally elevated left ventricular filling pressure; (7) anterior infarctions present greater depression of left ventricular function than inferior infarctions; and (8) monitoring of hemodynamics can be useful in following the changes in left ventricular function and the response to therapy in patients with heart failure and cardiogenic shock.
Asymmetrical Hypertrophic Cardiomyopathy Simulating Mitral Stenosis
Authors: SHABETAI RALPH , DAVIDSON SIDNEY
Published: June 2012

Hypertrophic cardiomyopathy usually involves the left ventricle more severely than the right, and when asymmetrical may produce the syndrome of idiopathic subaortic stenosis. Less commonly, clinical manifestations of inflow-tract obstruction predominate and produce a syndrome that may be mistaken for mitral stenosis, principally because of an apical diastolic rumbling murmur. The probability of this diagnostic error and the risk of a consequent unnecessary operation can be reduced by appreciating the significance of the clues to left ventricular disease revealed by the electrocardiogram and the chest roentgenogram. Furthermore, proper timing of the heart sounds differentiates the protodiastolic filling sound of cardiomyopathy from the opening snap of mitral stenosis. The correct diagnosis is established following ventriculographic and hemodynamic studies.
Hemodynamic Effects of Practolol at Rest and during Exercise
Authors: LEON DONALD F. , THOMPSON MARK E. , SHAVER JAMES A. , MCDONALD ROBERT H.
Published: June 2012

The effects of practolol, a new beta-adrenergic blocking agent, and propranolol were studied in volunteers. At rest, practolol caused a very small reduction in cardiac index (CI), 190 ml,
P
< 0.25, and preejection period (PEP) lengthened 3 msec,
P
< 0.025. In contrast, propranolol caused a reduction in CI of 770 ml,
P
< 0.001. Heart rate (HR) slowed 10 beats/min,
P
< 0.001, stroke volume index (SVI) fell 6 ml,
P
< 0.005, PEP lengthened 16 msec,
P
< 0.001, and peripheral vascular resistance (PVR) increased 419 dynes-sec-cm
–5
,
P
< 0.001. Practolol reduced the increase in CI caused by an isoproterenol infusion by 65%,
P
< 0.005, by blocking the increase in HR by 73%,
P
< 0.05. Practolol also reduced the shortening of PEP and LVET caused by isoproterenol. PVR decreases due to isoproterenol were not blocked by practolol although they were slightly attenuated,
P
< 0.025. Practolol reduced the increase in CI caused by exercise by 22%,
P
< 0.05, by blocking the increase in HR by 29%,
P
< 0.01. Practolol also reduced the increase in tension-time index due to exercise by 25%,
P
< 0.025.

Practolol has little effect on the performance of the normal heart at rest. It does block the cardiac effects of isoproterenol and exercise, largely through chronotropic mechanisms. The reductions in pressure-time relationships with exercise indicate reduced oxygen consumption by the heart, and therefore imply a therapeutic benefit in exercise-induced angina.
Primary Dissecting Aneurysm of Coronary Artery
Authors: CLAUDON DAVID G. , CLAUDON DANN B. , EDWARDS JESSE E.
Published: June 2012

Primary dissecting aneurysm of a coronary artery is a rare form of acute coronary arterial obstruction.

A review of 24 cases, including two observed by the authors, indicates that this condition tends to occur (1) in the young adult, (2) in the female more commonly than the male, and (3) relatively commonly in the postpartum state.

The clinical manifestations take the form either of sudden death or acute myocardial infarction. In the latter situation, there is the potential for overcoming the coronary arterial obstruction by a surgical bypass procedure.
Bundle of His Recordings in Congenital Complete Heart Block
Authors: KELLY DAVID T. , BRODSKY SIDNEY J. , MIROWSKI M. , KROVETZ L. JEROME , ROWE RICHARD D.
Published: June 2012

Six children, aged between 3 and 19 years, with congenital complete heart block without associated cardiac disease were studied by His bundle electrography. All were symptomatic with resting ventricular rates over 40 beats/min, and electrocardiograms that showed a normal axis and QRS complex. His bundle to ventricular activation was within the normal range in all and the block was proximal to the bundle of His. Ventricular and atrial pacing did not result in retrograde or antegrade conduction. All the patients were thought to have a lesion proximal to the site where the bundle of His potential was recorded and, therefore, were unlikely to develop symptoms or require treatment.
His Bundle Recordings in Children with Normal Hearts and Congenital Heart Disease
Authors: ROBERTS NIGEL K. , OLLEY P. M.
Published: June 2012

His bundle potentials were recorded in 50 children. Eight had normal hearts, 11 had ventricular septal defects, seven had the tetralogy of Fallot, seven had secundum atrial septal defects, and eight had pulmonary valve stenosis. There were miscellaneous defects in nine children. Ages ranged from 2 weeks to 14 years. Two intervals were measured on recordings: (1) from the initial atrial activity (P') to the His bundle potential (H), the P'-H interval, and (2) from H to the initial ventricular activity (V), the H-V interval. The H-V interval lengthened with age. The P'-H and H-V intervals did not differ significantly when different cardiovascular lesions were compared.
Suppression of Demand Pacemakers by Inactive Pacemaker Electrodes
Authors: WIDMANN WARREN D. , MANGIOLA STELIO , LUBOW LAWRENCE A. , DOLAN FAYETTA M.
Published: June 2012

Ventricular inhibited cardiac pacemakers were suppressed by intimate contact of the tip of the active pacemaker electrode with that of the inactive pacemaker electrode in two patients. This contact apparently was sensed as myocardial electrical activity and resulted in variable suppression of pacemaker emission. There was no interference with R-wave sensing function. The threshold for stimulation was unaffected. There was no loss of capture as tested with the magnet-controlled continuous mode of stimulation. This type of pacemaker failure can be remedied simply by withdrawing the tips of the electrodes from intimate contact.
Ultrasoundcardiographic Studies of the Mitral Valve Region in Young Infants with Mitral Atresia, Mitral Stenosis, Hypoplasia of the Left Ventricle, and Cor Triatriatum
Authors: LUNDSTRÖM NILS-RUNE
Published: June 2012

Reflected ultrasound has been used for investigation of the mitral valve region in early infancy. The material consists of two patients with mitral atresia, three patients with mitral stenosis and aortic valvular atresia, five patients with mitral and aortic valvular stenosis, one patient with cor triatriatum, and one patient with severe degree of aortic valvular stenosis with a normal mitral valve. The results are compared with ultrasoundcardiographic findings in ten infants without heart disease. A specific abnormal echo was obtained in cases with mitral atresia and cor triatriatum. The patients with a combination of mitral and aortic valvular lesions could be separated into two groups by means of ultrasoundcardiography. This separation reflected the functional state of the left ventricle based on the degree of mitral stenosis and hypoplasia of the left ventricle.

This noninvasive technic has been found useful as a complementary method for the investigation of the mitral valve region. It can even be performed in seriously ill infants.
Clinical Evaluation of Left Ventricular Pressures in Myocardial Infarction
Authors: PARMLEY WILLIAM W. , DIAMOND GEORGE , TOMODA HARUO , FORRESTER JAMES S. , SWAN H. J. C.
Published: June 2012

Left venitricular pressures were obtained in 14 patients with acute myocardial infarction, of whom seven survived. Calculated contractile element velocity (V
CE
), left ventricular end-diastolic pressure, and maximum dp/dt were compared with other hemodynamic measurements of LV function. V
CE
at 5 mm Hg (V
CE5
) was calculated according to the Maxwell three-component model of muscle and used as an index of overall contractile state. There was considerable overlap between survivors and nonsurvivors in the levels of V
CE5
, LVEDP, cardiac index, heart rate, and systemic vascular resistance. There was a reasonably good separation between survivors and nonsurvivors with measurements of mean arterial pressure, maximum LV dp/dt, mean isovolumic Δp/Δt, and stroke work. Changes in V
CE5
were no more sensitive after five inotropic interventions than ventricular function curves in monitoring changes in conitractile state. It is concluded that LV pressure measurements in acute myocardial infarction offer little further clinical information of importance beyond that which can be obtained from measurements of pulmonary capillary wedge pressure, arterial pressure, and cardiac output.
Nonparoxysmal Junctional Tachycardia Complicating Acute Myocardial Infarction
Authors: KONECKE LEE L. , KNOEBEL SUZANNE B.
Published: June 2012

Twenty-one instances of nonparoxysmal junctional tachycardia (NPJT) were observed in 203 consecutive patients with acute myocardial infarction. The arrhythmia complicated both anterior and inferior wall infarction and was associated with an ominous prognosis, particularly in patients with anteror wall infarction.

The NPJT is probably a manifestation of the severity of the lesion. The exact mechanisms of the enhanced A-V junctional activity remain obscure. The possible role of increased levels of epinephrine and norepinephrine and localized increases of potassium in the A-V junction from adjacent necrotic myocardium is suggested.
Systolic Time Intervals and Left Ventricular Function in Acute Myocardial Infarction
Authors: HAMOSH PAUL , COHN JAY N. , ENGELMAN KARL , BRODER MARTIN I. , FREIS EDWARD D.
Published: June 2012

Systolic time intervals (STI) were measured simultaneously with left ventricular pressure, right atrial pressure, and cardiac output in patients with acute myocardial infarction (AMI) within 24 hours of the onset of symptoms. Electromechanical systole (QS2) and left ventricular ejection time (LVET) were measured and preejection period (PEP) calculated and corrected for heart rate. LVET showed significant correlation with stroke volume (r = 0.62), confirming previous observations. Patients with significantly elevated left ventricular end-diastolic pressure (LVEDP) and clinical signs of congestive heart failure (CHF) usually exhibited a prolonged PEP when compared with normal subjects or patients with AMI who did not have signs of CHF. The normal PEP in the latter group might be due to adrenergic stimulation offsetting the effect of myocardial damage, although measurements of circulating catecholamines did not conclusively support this hypothesis. We conclude that STI are not reliable indices of left ventricular performance in AMI.
Disabling Supraventricular Tachycardia of Wolff-Parkinson-White Syndrome (Type A) Controlled by Surgical A-V Block and a Demand Pacemaker after Epicardial Mapping Studies
Authors: DUNAWAY MARSHALL C. , KING SPENCER B. , HATCHER CHARLES R. , LOGUE R. BRUCE
Published: June 2012

A patient with W-P-W syndrome (type A) and disabling supraventricular tachycardia was studied with epicardial mapping prior to surgical interruption of the circus pathway. Analysis of the delta vector and results of the epicardial mapping strongly suggested aberrant pathway located very posteriorly and crossing the atrioventricular sulcus in or adjacent to the interventricular septum. A circus movement responsible for the supraventricular tachycardia was felt to be a mechanism of antegrade A-V conduction and retrograde accessory bundle conduction. Attempts to interrupt the aberrant pathway primarily were unsuccessful, and surgical A-V block was performed. An epicardial demand pacemaker was inserted as a safety feature. Since the operation the patient has been free of supraventricular tachycardia. The postoperative electrocardiograms demonstrated antegrade accessory pathway conduction, but neither antegrade nor retrograde A-V conduction. Failure to interrupt the accessory pathway after incision of the entire right posterior A-V sulcus supported a location with, or to the left of, the atrioventricular septum for the pathway. This case, with the recent results of others, adds to the further understanding of accessory pathway location in W-P-W syndrome (type A).
Wolff-Parkinson-White Syndrome
Authors: RAMACHANDRAN S.
Published: June 2012

This paper reports a patient with Wolff-Parkinson-White syndrome who presented with a tachycardia showing an unusual QRS morphology closely resembling that of a ventricular tachycardia. On reversal to a normal rhythm the electrocardiogram showed changes of a type A preexcitation, with subsequent conversion to a type B pattern. This phenomenon was observed on two separate occasions. Such conversion would suggest the presence of two distinct sites for bypass location resulting in preexcitation, thus lending support to the theory of aberrant atrioventricular conduction via a bundle of Kent or neuromuscular tissue connecting atrium to ventricle. The configuration of the QRS complexes during the tachycardia would appear to be due to a circus movement with antegrade anomalous atrioventricular conduction and retrograde atrial stimulation via the bundle of His, although in this case, due to the presence of two distinct anomalous atrioventricular conduction pathways, both antegrade and retrograde conduction via these two pathways alone cannot be excluded.
Blood-Gas Changes and Pulmonary Hemodynamics following Acute Myocardial Infarction
Authors: FILLMORE SIDNEY J. , GUIMARÃES ARMENIO C. , SCHEIDT STEPHEN S. , KILLIP THOMAS
Published: June 2012

Arterial and mixed venous oxygen tensions were measured in 24 patients following acute myocardial infarction while they were breathing air and 100% oxygen. Total venous admixture and the right-to-left shunt during 100% oxygen breathing were calculated. These data were related to the pulmonary arterial diastolic pressure, the cardiac index, and the central blood volume.

Patients with myocardial infarction that was not complicated by congestive failure had blood gases, pulmonary shunts, and pulmonary arterial diastolic pressures comparable to control patients who were at rest in bed.

When congestive failure complicated myocardial infarction, arterial blood oxygen tension was lower, pulmonary shunting was increased, and the pulmonary arterial diastolic pressure was elevated. Cardiac index and central blood volume were usually normal.

The present data quantitate the contribution of anatomic shunting to the hypoxemia observed in myocardial infarction. Hypoxemia and increased anatomic shunting are closely correlated to the degree of elevation of pulmonary arterial diastolic pressure. The interrelationships of arterial hypoxemia, venous admixture, arterial-alveolar oxygen gradient, and pulmonary arterial diastolic pressure suggest that pulmonary venous congestion is an important determinant of the hypoxemia and shunting observed in patients with acute myocardial infarction.
Premature Closure of the Mitral and Tricuspid Valves
Authors: SPRING DONALD A. , FOLTS JOHN D. , YOUNG WILLIAM P. , ROWE GEORGE G.
Published: June 2012

Premature closure of an atrioventricular valve was observed in 80 of a group of 519 subjects catheterized for aortic insufficiency (AI) or mitral insufficiency (MI), or both. Sole premature mitral closure (PMC) was present in nine subjects, sole premature tricuspid closure (PTC) in 40, and combined PMC and PTC in 31. Clinically PMC was associated with a first sound that was soft or absent in 75% and an atrial contraction sound in 50% of the subjects with dominant aortic insufficiency. PMC or PTC, or both, were verified at surgery in three subjects and were produced experimentally in intact dogs by acute AI. The presence of PMC and PTC appears related to the severity and chronicity of valvular disease.
Myocardial Ultrastructure in Idiopathic Hypertrophic Subaortic Stenosis
Authors: FERRANS VICTOR J. , MORROW ANDREW G. , ROBERTS WILLIAM C.
Published: June 2012

Electron microscopic studies revealed distinctive abnormalities in operatively resected myocardium from the left ventricular outflow tract in 14 patients with idiopathic hypertrophic subaortic stenosis. Bundles of muscle cells were severely disorganized, with cells running in different directions instead of in parallel. Muscle cells were wider and shorter than in hypertrophy due to other causes and showed increased cellular branching, extensive side-to-side intercellular junctions, widened Z bands, and evidence of formation of new sarcomeres. Some myofibrils were oriented obliquely or perpendicular to the longitudinal axes of the cells and some myofilaments that originated from a single Z band inserted into Z bands of other myofibrils. Examination of left ventricular apical myocardium in two patients revealed hypertrophied but normally arranged muscle cells. It is concluded that abnormal architecture of muscle cells is the basic morphologic feature of idiopathic hypertrophic subaortic stenosis.
Tricuspid Insufficiency
Authors: HANSING CHARLES E. , ROWE GEORGE G.
Published: June 2012

The clinical diagnosis of the presence and severity of tricuspid insufficiency is difficult and is complicated by the transient nature of this abnormality as well as its usual occurrence in subjects with other valve disease. This paper presents correlative hemodynamic data from 100 consecutive catheterized patients with valvular heart disease in 90 of whom the presence of tricuspid insufficiency was sought by the indicator-dilution technic. Tricuspid regurgitation was present in 28 of the 90 patients. Subjects were grouped into 20 controls without tricuspid insufficiency and those with mild, moderate, and severe tricuspid insufficiency. The hemodynamics of these groups were compared by the analysis of variance to determine which parameters relate most closely to tricuspid insufficiency. The results are interpreted to confirm that tricuspid insufficiency results from those factors which overdistend the right side of the heart, and by permitting blood to escape retrograde from the right ventricle serves as a safety valve preventing progressive overload of the pulmonary circulation.
Basement Membrane Changes in Myocardial and Skeletal Muscle Capillaries in Myxedema
Authors: MCFADDEN P. M. , BERENSON G. S.
Published: June 2012

Nineteen dogs were given
131
I and later administered appropriate amounts of methimazole or propylthiouracil daily. Over a period of 4-7 years several developed severe clinical features of myxedema. The myocardium and skeletal muscle of these severely myxedematous dogs displayed an array of morphologic changes on an ultrastructural level. Particularly interesting was the two- to threefold increase in the thickness of the myxedematous capillary basement membranes over those of normals. Increased tortuosity, lamination, and perivascular fibrosis were also observed as part of the myxedematous changes. These studies also demonstrated severe microcellular modifications, such as mitochondrial disruption, loss of cristae, lipid inclusions, and the presence of myelin figures, all a part of the diffuse systemic cardiovascular connective tissue pathology in myxedema.
Interrelationship of Serum Lipids with Relative Weight, Blood Glucose, and Physical Activity
Authors: GARCÍA-PALMIERI MARIO R. , COSTAS RAÚL , SCHIFFMAN JOYCE , COLÓN ANGEL A. , TORRES RAQUEL , NAZARIO EMILIO
Published: June 2012

Serum cholesterol, serum glyceride, blood glucose, relative weight, physical activity, percent calories from fat, percent calories from carbohydrate, and polyunsaturated/saturated fatty acid (P/S) ratio were determined in 1780 rural and 4023 urban fasting men aged 45-64 years being followed prospectively to ascertain reasons for the low prevalence of coronary heart disease mortality in Puerto Rico as compared to other countries. Lipid and glucose levels and relative weight were higher and physical activity lower in urban men. Glyceride was positively correlated with cholesterol, glucose, and relative weight, and negatively correlated with physical activity. Cholesterol was positively correlated with glyceride, glucose, and relative weight, and not correlated with physical activity. Percent calories from fat and P/S ratio were significantly higher and percent carbohydrates from starch significantly lower in urban men. These variables taken together were not significant in predicting the differences between urban and rural serum cholesterol or glyceride values. Relative weight was the most significant variable in explaining urban-rural differences in serum glyceride and cholesterol levels. These findings confirm the importance of weight control in dietary management for reduction of serum lipids.
Left Ventricular Performance before and after Removal of the Noncontractile Area of the Left Ventricle and Revascularization of the Myocardium
Authors: KITAMURA SOICHIRO , ECHEVARRIA MAX , KAY JEROME HAROLD , KROHN BERNARD G. , REDINGTON JOHN V. , MENDEZ ADOLFO , ZUBIATE PABLO , DUNNE EDWARD F.
Published: June 2012

The left ventricular volume and the internal surface areas of noncontractile regions were measured by cineangiocardiography at 60 frames/sec in nine patients with a chronic localized noncontractile area of the left ventricle. Arteriosclerotic heart disease was proven in eight patients by means of coronary arteriography. Left ventricular end-diastolic pressure, stroke volume, ejection fraction, mean circumferential shortening, and cardiac output were also measured before and after removal of the noncontractile area and revascularization of the myocardium.

The noncontractile areas, measured at end-diastole, ranged from 12 to 40% of the internal surface area of the left ventricle. Generally, impairment of the left ventricular function depended on the size of the noncontractile areas. The end-diastolic volume was approximately 150 ml/m
2
when the size of noncontractile areas exceeded 20-25% of the left ventricular surface area (r = +0.72;
P
< 0.05). The ejection fraction decreased as the size of the noncontractile areas increased (r = –0.81;
P
< 0.01). Following surgery, the left ventricular function, as well as the clinical condition, improved significantly, although the cardiac performance remained in the abnormal range in most patients. The ejection fraction increased (
P
< 0.05), and the percent circumferential shortening also improved (
P
< 0.05).

Removal of the noncontractile area of the left ventricle and revascularization of the myocardium improved the cardiac performance and increased the sense of well being in these patients.
Arrhythmias following Cardiac Valve Replacement
Authors: SMITH ROGER , GROSSMAN WILLIAM , JOHNSON LEWIS , SEGAL HERMAN , COLLINS JOHN , DALEN JAMES
Published: June 2012

A prospective study of 50 consecutive patients undergoing cardiac valve replacement was designed to determine the incidence, types, and predisposing factors to postoperative arrhythmias. Patients were monitored continuously for the first 7 days following surgery.

Thirty-seven patients (74%) experienced a total of 66 episodes of arrhythmia. Supra-ventricualr arrhythmias were the most common (43 of 66; 65%). The most frequent specific arrhythmia was atrial fibrillation (21 of 66; 32%). Arrhythmias occurred 77% of the time within the first 48 hours of surgery.

Of 25 factors evaluated preoperatively in each patient, only two were found to predispose to postoperative arrhythmias. These were: (1) previous cardiac surgery; and (2) elevated blood urea nitrogen.

There were four hospital deaths, representinig a hospital mortality of 8%. No deaths were due to a primary arrhythmia.

It is concluded that whereas arrhythmias are a very common complication of cardiac valve replacement, early detection and treatment has lessened their significance as a cause of postoperative mortality and morbidity.
Effectiveness of Bretylium Tosylate against Refractory Ventricular Arrhythmias
Authors: BERNSTEIN JERROLD G. , KOCH-WESER JAN
Published: June 2012

Thirty patients with ventricular tachyarrhythmias, which had not responded to intensive therapy with up to five antiarrhythmic drugs, were treated with bretylium tosylate. All patients had recurrent ventricular tachycardia, and 12 had repeated episodes of ventricular fibrillation. In 17 patients the arrhythmias followed acute myocardial infarction. Bretylium was administered intramuscularly or intravenously, and most patients received 4-5 mg/kg every 6 hours. Eighteen patients responded satisfactorily to bretylium and suffered no further ventricular tachyarrhythmias while receiving the drug. Bretylium partially suppressed ventricular arrhythmic activity in five patients and had no beneficial effects in seven patients. Administration of bretylium soon after the development of arrhythmias and withholding of other antiarrhythmic drugs during bretylium therapy favored a good antiarrhythmic response. Hypotension followed bretylium administration in 19 patients but exceeded 20 mm Hg in only one patient. Transient initial increases in blood pressure and ventricular arrhythmic activity occurred in five and four patients, respectively. Six patients were discharged from the hospital on oral bretylium 600 mg every 6 hours, and all have remained free from major ventricular arrhythmias for up to 15 months. In these patients postural hypotension was a transient and parotid pain a persistent side effect.
Preexcitation and Tachycardias in Wolff-Parkinson-White Syndrome, Type B
Authors: LISTER JOHN W. , WORTHINGTON FRANCIS X. , GENTSCH THOMAS O. , SWENSON JOHN A. , NATHAN DAVID A. , GOSSELIN ARTHUR J.
Published: June 2012

Electrophysiologic events in a 52-year-old man with Wolff-Parkinson-White (W-P-W) syndrome, type B, recurrent supraventricular tachycardias, and coronary artery disease were studied during cardiac catheterization and at open-heart surgery.

During cardiac catheterization reciprocal tachycardias were repeatedly initiated by premature atrial beats and terminated by rapid right atrial pacing. Our results confirm that the tachycardia usually seen in the W-P-W syndrome is reciprocal tachycardias with orthograde conduction to the ventricles through the normal atrioventricular conduction system and retrograde conduction to the atria via the Kent bundle.

The epicardial surface of the ventricles was "mapped" at surgery. The earliest site of excitation was the posterior base of the left ventricle near the crux of the heart. Kent bundle conduction was temporarily ablated with lidocaine (Xylocaine) hydrochloride.

This is the first case of W-P-W syndrome, type B, in which the anomalous A-V bundle entered the left ventricle. Our results indicate that the analysis of the electrocardiogram in localizing an abnormal A-V connection cannot be relied upon completely.
Hemodynamic Spectrum of Myocardial Infarction and Cardiogenic Shock
Authors: SWAN H. J. C. , FORRESTER JAMES S. , DIAMOND GEORGE , CHATTERJEE KANU , PARMLEY WILLIAM W.
Published: June 2012

Despite the recent accumulation of a large hemodynamic data base describing myocardial infarction and cardiogenic shock, precise characterization of patient subsets has been elusive. This paper represents an attempt to identify the major factors contributing to this wide hemodynamic spectrum, and their interrelation using a theoretical model based upon currently emerging concepts of this disease. It is proposed that the hemodynamic alterations associated with acute infarction are a consequence both of reduction in contractile mass and alteration in left ventricular compliance. In addition, mitral insufficiency, altered contractility, and the peripheral circulation interact to produce wide divergence between clinical and hemodynamic features from case to case and during the progression of the course of the illness. This model may more rationally explain the genesis and natural history of "heart failure" and the "shock syndrome" associated with acute myocardial infarction and in addition explain the extremely variable responses to both drug therapy and to more aggressive modes of treatment of power failure.
Left Ventricular Preejection Period and Ejection Time in Patients with Acute Myocardial Infarction
Authors: HODGES MORRISON , HALPERN BARRY L. , FRIESINGER GOTTLIEB C. , DAGENAIS GILLES R.
Published: June 2012

The phases of systole were measured in 51 patients with acute myocardial infarction and three control groups: (1) a group of 40 patients without heart disease, (2) a group of 23 patients admitted to a coronary care unit for chest pain, who did not have an acute myocardial infarction, and (3) a group of 16 patients with stable angina pectoris and arteriographically proven coronary atherosclerosis. In addition, serial measurements were made in the acute myocardial infarction group. Total electricalmechanical systole (QS
2
), the preejection period (PEP), and left ventricular ejection time (LVET) were measured in each patient from simultaneous recordings of the ECG, phonocardiogram, and carotid pulse tracing. The systolic and diastolic blood pressures and QRS duration were also measured. Corrections were made for heart rate where appropriate.

The average PEP was elevated on the first day of myocardial infarction but was within normal limits thereafter. The LVET and QS
2
were significantly shortened until the fourth week of hospitalization. There was considerable overlap in the PEP values among the four groups. Eight patients died of acute myocardial infarction; the PEP was abnormally short in three (two of whom had cardiogenic shock), normal in two, and abnormally long in three. The PEP/LVET ratio separated the acute MI group from the normal group but not from the other two patient groups. Clinical class, digitalis, and infarct location did not produce characteristic changes in the systolic time intervals.

A reduction in stroke volume is the most likely explanation for the reduction in LVET and QS
2
. The wide range in PEP values observed is best explained by alterations in the multiple determinants of PEP.

The systolic time intervals do not appear to be useful as a diagnostic or prognostic tool in acute myocardial infarction.
Type IV Hyperlipoproteinemia in a Consanguinous Family
Authors: AMIDI MORTEZA
Published: June 2012

The involvement of all five offspring of consanguinous and hypertriglyceridemic parents (first cousins) is reported.

Three sons and two daughters of this family have increased triglycerides, normal cholesterol, and normal or slightly increased phospholipids. Mother and elder daughter have abnormal glucose tolerance. Father and mother are hypertensive; father had recent development of myocardial infarction and gout. The two elder sons had myocardial infarction and repeated bouts of angina. All three male offspring of this family have gout and are being treated with xanthinoxidase inhibitor (allopurinol). Planar xanthoma was present in one son with myocardial infarction. No chylomicronemia was noted. The response to diet and Atromid-S was satisfactory.
Effects of Treatment on Morbidity in Hypertension
Authors:   VETERANS ADMINISTRATION COOPERATIVE STUDY GROUP ON ANTIHYPERTENSIVE AGENTS
Published: June 2012

Additional data are presented from the Veterans Administration Cooperative Study with respect to the 194 control and 186 treated male patients with initial diastolic blood pressures averaging 90-114 mm Hg. Attack rates and effectiveness of treatment were examined with respect to the following risk factors present at entry: (1) cardiovascular-renal (CVR) abnormalities, the prevalence of which was higher than in the general population of hypertensive patients; (2) diastolic blood pressure; and (3) age. Both attack rates and effectiveness of treatment increased directly with the number of these risk factors present at entry. Age and presence of CVR abnormalities at entry appeared to strongly influence subsequent attack rates, whereas entry level of blood pressure had a relatively smaller effect on attack rates. On the other hand, "effectiveness of treatment" appeared to be most influenced by the initial level of blood pressure. Patients with prerandomization diastolic blood pressure in the range of 90 to 104 mm Hg derived relatively little benefit from treatment unless they had CVR abnormalities at entry or were over 50 years of age. A longer period of follow-up would be needed to assess the value of treatment in the lower risk subgroups.

With respect to side effects, the incidence of mild hypokalemia, hyperuricemia, and elevated fasting blood sugar was significantly higher in the treated group. These and other side effects should be weighed against the benefit to be expected from treating hypertensive patients at low risk.
Hemodynamic Observations One and Two Years after Cardiac Transplantation in Man
Authors: STINSON EDWARD B. , GRIEPP RANDALL B. , SCHROEDER JOHN S. , DONG EUGENE , SHUMWAY NORMAN E.
Published: June 2012

Cardiac catheterization studies were performed in eight patients 1 year after cardiac transplantation and in two of these again at 2 years. Intracardiac pressures at rest were normal in all patients, both 1 and 2 years postoperatively. Average cardiac index at rest at 1 year was 2.3 liters/min/m
2
and average heart rate was 90 beats/min. Responses to amyl nitrite, atropine, and tyramine failed to demonstrate efferent autonomic reinnervation of the donor hearts. Findings associated with a 10-min period of submaximal supine bicycle exercise 1 year after transplantation included: (1) a gradual rise in heart rate throughout most of the exercise period; (2) prompt elevation of left ventricular end-diastolic pressure by an average increment of 10 mm Hg, followed by a decrease during late exercise in some patients; (3) a progressive increase in LV systolic pressure throughout the first half of the exercise period; (4) a continuously positive change in LV rate of pressure change (dp/dt) throughout exercise; (5) an average 44% increase in stroke volume; and (6) an average 92% increase in cardiac output. The slope of the regression of cardiac output on oxygen uptake during exercise was within the range of normal. Cardiac output, however, was lower than normal both at rest and during exercise, and the arteriovenous oxygen diflerence was accordingly widened.

In one patient studied 1 and 2 years after transplantation, hemodynamic findings were comparable on both occasions. In the other, however, the cardiac output response to exercise was distinctly diminished at 2 years as compared to 1 year, due almost entirely to failure of the stroke volume to increase. Coronary arteriography in this recipient revealed evidence of occlusive coronary disease compatible with graft atherosclerosis.

These studies demonstrate the sustained capacity of the transplanted human heart to support normal physical activity late in the postoperative period. Although utilizing atypical adaptive mechanisms characteristic of the denervated heart, the transplanted heart responds in a directionally appropriate manner to the metabolic demands of exercise.
Normal and Prosthetic Atrioventricular Valve Motion in Atrial Flutter
Authors: ALDERMAN EDWIN L. , RYTAND DAVID A. , CROW RICHARD S. , FINEGAN ROBERT E. , HARRISON DONALD C.
Published: June 2012

In order to correlate the electrical and mechanical events occurring in atrial flutter, three patients have been studied using the standard electrocardiogram, a computer-processed vectorcardiogram, and reflected ultrasound recordings of valvular motion. Anterior motion of the mitral valve leaflet occurs in the region of the nadir of the atrial flutter wave in lead II of the electrocardiogram. In one patient in whom it was possible to obtain a tricuspid leaflet echocardiogram, anterior motion was also initiated close to the nadir of the flutter wave. The probable sequence of electrical and mechanical events in atrial flutter is discussed. In one patient with a prosthetic mitral valve, correlation of diastolic clicking sounds with respect to the poppet echocardiogram provided some insight into irregularities in timing of previously reported flutter sounds.
Management of Total Anomalous Pulmonary Venous Return
Authors: EL-SAID GALAL , MULLINS CHARLES E. , MCNAMARA DAN G.
Published: June 2012

The effects of age, type of return, presence of pulmonary venous obstruction, obstruction to left heart filling, systemic arterial oxygen saturation (Ao O
2
%), pulmonary-to-systemic flow ratio (Q
p
/Q
p
), pulmonary-to-systemic resistance ratio (R
p
/R
s
%), and mean pulmonary artery-to-mean systemic arterial pressure ratio (MPAP/MSAP%) in 35 cases of total anomalous pulmonary venous return seen in the last 5 years, were studied in relation to prognosis and management. The surgical mortality was increased in patients with anomalous venous return to the right common cardinal system (right superior vena cava and azygos vein) regardless of age and was significantly lower in patients over 6 months of age and in those who had preoperative intensive medical management. No relation was found between surgical mortality and Ao O
2
%, R
p
/R
s
, MPAP/MSAP%, or the presence of pulmonary venous obstruction. The small size of the left atrium rather than the small size of the left ventricle is felt to be one of the reasons for operative failure. The importance of obstruction to left heart filling at the atrial level was stressed. Until technics for surgical treatment of this group of anomalies in early infancy become more successful, we recommend balloon atrial septostomy in combination with intensive medical management as effective palliative treatment for most of these patients in the first 6 months of life.