bluuebunny/crossref_metadata_2025 huggingface dataset:
Measurement of Pulmonary Edema in Valvular Heart Disease
Authors: MCCREDIE MICHAEL
Published: June 2012

Pulmonary extravascular fluid volume (PEV) has been estimated by using a double isotope technique in nine normal subjects and 45 patients with valvular heart disease. The method was reproducible, the standard deviation being±15.2 ml/m
2
, or 11.2% of the mean.

Groups of patients with aortic and mitral valve disease had significantly higher values of PEV than normal persons; some patients with pulmonary stenosis had subnormal values. There was a relationship between PEV and the severity of dyspnea; all patients with an abnormally high PEV were class II or worse. Of the 18 patients with abnormally high PEV, only seven had radiological evidence of chronic pulmonary edema.

PEV was independent of blood flow but was clearly related to the level of pulmonary intravascular pressure. PEV was only significantly elevated if left atrial mean pressure exceeded 12 mm Hg and was invariably raised if it exceeded 25 mm Hg. No relationship of PEV to pulmonary vascular resistance was evident in this study.
Valvular Stenosis Produced by Active Infective Endocarditis
Authors: ROBERTS WILLIAM C. , EWY GORDON A. , GLANCY D. LUKE , MARCUS FRANK I.
Published: June 2012

Two patients with obstructed valve orifices secondary to infective endocarditis are described. In one patient the mitral valve orifice was obstructed by large streptococcal vegetations, and in the second, the aortic valve orifice was obstructed by fungal vegetations. The occurrence of obstructive valvular lesions secondary to infective endocarditis is rare.
Noradrenaline Release and Metabolism in Orthostatic (Postural) Hypotension
Authors: GOODALL McC. , HARLAN W. R. , ALTON H.
Published: June 2012

Fifteen hypotensive patients were studied of whom only seven could be classified as having idiopathic orthostatic (postural) hypotension. These seven patients showed a marked decrease in their urinary output of the sympathetic neurohormone, noradrenaline. Furthermore, the rate of metabolism of circulating noradrenaline was somewhat less than normal; however, there was no significant alteration in noradrenaline metabolites. One patient, on whom autopsy was performed, showed degeneration of the sympathetic ganglia and nerves. Although there was infiltration with amyloid in these areas, it was not certain that amyloidosis was the primary disease. Nevertheless, there was an anatomic loss of the neurogenic structures involved in the synthesis of noradrenaline, which could explain the subnormal output of noradrenaline. Whereas, these results do not permit a definite conclusion that in idiopathic orthostatic hypotension there is an anatomic deficit or a decrease in efferent sympathetic neurons, nevertheless, evidence is presented which would seem to indicate this as the probable etiology.
Physiological Significance of Maximal Oxygen Intake in "Pure" Mitral Stenosis
Authors: BLACKMON JOHN R. , ROWELL LORING B. , KENNEDY J. WARD , TWISS RICHARD D. , CONN ROBERT D.
Published: June 2012

Acute circulatory and respiratory adjustments to mild through maximal upright exercise were studied in seven patients with "pure" mitral stenosis. Maximal oxygen uptake was determined objectively by demonstrating a plateau of oxygen uptake with increasing workloads. Time to reach a plateau of oxygen uptake was normal (2 to 3 minutes) at all workloads. At any given oxygen uptake, cardiac output and hepatic clearance of indocyanine green (ICG) were abnormally low while total arteriovenous (A-V) oxygen difference, heart rate, blood lactate, and ventilation were abnormally high. However, with respect to relative oxygen uptake (per cent of maximal oxygen uptake), the reduction in cardiac output was exaggerated, but A-V oxygen difference, heart rate, blood lactate, and hepatic clearance of ICG were essentially normal. RQ and V
E
/V

O
O2

were quantitatively abnormal even with respect to relative oxygen uptake, but the pattern of changes from mild to maximal exercise was normal. Low maximal oxygen uptake defined the reduction in stroke volume while other circulatory responses were normal with respect to relative oxygen uptake.
Atrioventricular and Ventriculoatrial Excitation in Wolff-Parkinson-White Syndrome (Type B)
Authors: BURCHELL HOWARD B. , FRYE ROBERT L. , ANDERSON MILTON W. , McGOON DWIGHT C.
Published: June 2012

A patient with an atrial septal defect, paroxysmal tachycardia, and the Wolff-Parkinson-White syndrome (type B) had epicardial exploration to determine the nature of the excitation anomaly. Right bundle-branch block in association with the WPW syndrome (type B) was evidenced by the late activation (0.12 sec) of the epicardium over the outflow tract of the right ventricle. Early activation of the base of the right ventricle (near the atrioventricular groove at the right border of the heart) was interpreted as indicating an actively conducting atrioventricular muscle bridge (bundle of Kent) in this region. During paroxysms of tachycardia, the ventricular area excited much later than when sinus mechanism was present, and the adjacent right atrium was excited in sequence. This sequence supported the concept of a circus movement, that is, movement from atrium to ventricle via atrioventricular bundle (His) and ventricle to atrium via a muscle bridge (Kent). Injection of procaine into the base of the right ventricle abolished the pre-excitation of the ventricle.
Angiographic Anatomy of the Left Ventricle and Mitral Valve in Idiopathic Hypertrophic Subaortic Stenosis
Authors: SIMON ALLAN L. , ROSS JOHN , GAULT JAMES H.
Published: June 2012

The angiographic features of the left ventricle were examined in patients with idiopathic hypertrophic subaortic stenosis who had clinical and hemodynamic evidence of obstruction. Of 36 combined hemodynamic and angiographic studies considered to be technically satisfactory, 33 showed a characteristic combination of abnormalities. In the frontal projection in systole, a linear radiolucent area extended across the left ventricular outflow tract 2 to 2.5 cm below the aortic annulus, at a level corresponding to the site of intraventricular pressure change. In the left oblique and lateral projections, the mitral leaflets did not swing posteriorly in a normal fashion, but projected into the outflow tract during mid and late systole. The radiolucent line, seen in the frontal views, was considered to represent contact of the leading edge of the leaflet with the hypertrophied muscular interventricular septum. The jet of mitral regurgitation, when present, was seen immediately below the anterior mitral leaflet.

Severe hypertrophy was also seen to involve the inferior portion of the muscular septum, causing displacement of the papillary muscles superiorly and to the left. This maldirection of the papillary muscles was postulated to cause abnormal traction on the chordae tendineae and to prevent normal movement of the mitral leaflets away from the septum during systole. The leaflets, held in the outflow tract, form the posterior component of the obstruction, the anterolateral component of which results from severe, asymmetric septal hypertrophy. It was proposed that this mechanism plays an important part in producing the intraventricular pressure gradient in many patients with idiopathic hypertrophic subaortic stenosis.
Cineangiocardiographic Studies of the Left Ventricle in Patients with Angina Pectoris
Authors: BJÖRK LARS , CULLHED INGEMAR , HALLÉN ADAR
Published: June 2012

The findings at coronary angiography and left ventricular cineangiography were compared with clinical data in 52 cases of coronary artery disease. A semiquantitative estimation of left ventricular end-diastolic and end-systolic volumes was used, as well as the identification of local dysfunction in the left ventricular wall. The findings at ventriculography had no relation to the functional classification or the maximal physical work capacity. Thus the limiting factor is angina pectoris and not primarily changes in the left ventricular wall after infarction. Similarly, retrograde filling of stenosed arteries by collateral channels was not correlated to the degree of left ventricular dysfunction or to physical work capacity. Patients with slight to moderate coronary artery stenosis had a normal left ventricular contraction pattern, and in no instance did the electrocardiogram indicate previous myocardial infarction. On the other hand, a normal electrocardiogram as well as a normal left ventricular contraction pattern was seen with severe coronary artery stenosis. There was a fair correspondence between the localization of infarcts according to the electrocardiograms and the left ventricular angiograms. There seemed to be more false negative electrocardiographic diagnoses of posterior-than of anterior-wall infarction. It is concluded that left ventricular angiography provides anatomic and some physiological information that no other method can give. Its use with other clinical and laboratory methods adds considerably to the accuracy in diagnosis and evaluation of patients with coronary artery disease.
Digital Computer Analysis of the Vectorcardiogram of the Newborn Infant
Authors: AINGER LORIN E. , Brignole Patrick J. , Campbell Bill R.
Published: June 2012

Data derived from digital computer analysis of three corrected lead recordings for each of 13 term, normal newborn infants obtained on the first day of life are reported. The Frank, Schmitt SVEC-III, and McFee axial systems recorded the time sequence of ventricular depolarization force orientation in an almost identical manner. The following electrocardiographic measurements are reported for each of the three lead systems: heart rate, P-R interval, QRS and S-T intervals, planar and spatial mean P vectors, successive planar mean instantaneous QRS vectors, maximum QRS spatial vector, maximal rightward and leftward QRS spatial vectors, mean and maximum planar and spatial T vectors, and planar and spatial ventricular gradients. In general, vector quantities during this period of life are of lesser magnitude and more variable in orientation than for older infants and children. Although newborn infant ventricular depolarization forces for the majority are directed anteriorly, to the right, and inferiorly, posterior and superior orientation is not uncommon.
On the Path of the Excitation Wave in Atrial Flutter
Authors: STIBITZ GEORGE R. , RYTAND DAVID A.
Published: June 2012

Available data on the arrival times of excitation at various central and peripheral atrial sites during atrial flutter (in a number of dogs and in one patient) have been examined in relation to families of involutes of an arbitrary central obstacle. The degree of fit seems to be satisfactory and is superior to that made for the same data by central-centrifugal (mother-daughter) waves. The latter appear to be an erroneous corollary of the circus movement hypothesis. In contrast, the concept that successive wave fronts of an entrapped circuit wave in atrial flutter may be described by a family of involutes has an appropriate physiological basis in the construction of Huygens, as first suggested by Wiener and Rosenblueth.
Relation of Sodium Balance to Arterial Pressure During Drug-Induced Saluresis
Authors: FINNERTY FRANK A. , DAVIDOV MICHAEL , KAJAVIATOS NIKOS
Published: June 2012

Serial determinations of plasma volume and urinary sodium excretion were determined during saluresis in 20 hypertensive patients. Although the diuretics produced a decrease in plasma volume and an increase in urinary sodium excretion in all patients, there was no direct relationship between the decrease in plasma volume and the fall in arterial pressure. Concomitant administration of dextran solution prevented the reduction in plasma volume but did not prevent the fall in arterial pressure. Similarly, replacement of plasma volume with dextran solution at the peak of hypotension following the diuretics had no effect on the reduced arterial pressure. Concomitant administration of hypertonic saline solution with the diuretic prevented the fall in arterial pressure, and the replacement of urinary sodium loss at the peak of hypotension returned the arterial pressure to control values when the sodium administered exceeded the urinary sodium loss. It would seem that in the hypertensive sodium depleted state a direct relationship exists between arterial pressure and sodium balance. Thus, a positive sodium balance is associated with a rise in arterial pressure, whereas a negative sodium balance is associated with a fall in arterial pressure. The data suggest also that the decreased pressor response during saluresis is due more to the production of negative sodium balance than to a decrease in plasma volume.
Paroxysmal Ventricular Fibrillation in Two Patients with Hypomagnesemia
Authors: LOEB HENRY S. , PIETRAS RAYMOND J. , GUNNAR ROLF M. , TOBIN JOHN R.
Published: June 2012

Paroxysmal ventricular fibrillation unassociated with heart block occurred in two patients with hypomagnesemia. In neither patient were other causes of the arrhythmia apparent. Temporary transvenous pacing successfully suppressed the episodes after drug therapy failed. Prolongation of the Q-T interval was a prominent electrocardiographic feature in both patients and is postulated to have resulted from a loss of intracellular potassium secondary to hypomagnesemia.
Arterial Pressure Responses to Discontinuing Antihypertensive Drugs
Authors: DUSTAN HARRIET P. , PAGE IRVINE H. , TARAZI ROBERT C. , FROHLICH EDWARD D.
Published: June 2012

A wide spectrum of arterial pressure responses to discontinuing long-term antihypertensive drug treatment was found in 65 patients. In five, spontaneous pressure variations prevented judging effects of drug discontinuance. Of the remaining 60, pressure returned to pretreatment levels in 21, and rose toward control levels in 37; while in two, diastolic hypertension did not reappear in more than 8 years. Rate of rise of arterial pressure seemed related to type of hypertension and to height of diastolic pressure and severity of vascular disease before treatment. In six of nine patients who had had malignant hypertension and six of nine with renal arterial disease, pressure rose promptly and treatment was restarted within a month. Among essential hypertensive patients, those who remained off treatment for 2 to 6 months had significantly lower pretreatment pressure than those whose hypertension returned in less than 2 months. The two whose diastolic hypertension seemed "cured" had no distinguishing features.

These results suggest that most hypertensive patients require continuous treatment for good pressure control; downward resetting of pressure by treatment is rare.
Immediate Hemodynamic Effects of Beta-Adrenergic Blockade with Propranolol in Normotensive and Hypertensive Man
Authors: ULRYCH MILOS , FROHLICH EDWARD D. , DUSTAN HARRIET P. , PAGE IRVINE H.
Published: June 2012

Immediate hemodynamic effects of beta-adrenergic blockade were determined in six normal subjects and 21 hypertensive patients following intravenous administration of propranolol. Arterial pressure was not reduced, but cardiac output fell by approximately 20% in both groups. Nevertheless, beta-adrenergic inhibition seemed to have different effects in the two groups: Propranolol produced a greater inhibition of chronotropic activity in the hypertensive patients, and of stroke volume in the normotensive individuals whose pretreatment heart rate was slower than that of the hypertensives. This difference suggests that chronotropic beta-adrenergic activity may be increased in hypertension but does not explain reduction in arterial pressure following oral treatment with propranolol.
Sex Differences in the Vectorcardiogram
Authors: SOTOBATA IWAO , RICHMAN HAROLD , SIMONSON ERNST , Fukomoto A.
Published: June 2012

In a study of 101 normal men and 102 normal women (mean age, 42.5 and 42.6 years, respectively), significant sex differences were observed in 43 of 64 vectorial items analyzed (initial 0.02-sec and 0.025-sec vectors, maximal QRS and T vectors, terminal 0.02-sec vectors in frontal, horizontal left sagittal planes; Q, R, S, and T deflections in Frank's X, Y, and Z leads). The initial QRS vectors are oriented more inferiorly and posteriorly in women than in men, the maximal QRS vectors more inferiorly, the terminal vectors more leftward and superiorly, the T vector more posteriorly and inferiorly. The QRS-T angle is smaller. There is a significant tendency to smaller magnitude of all planar vectors and Q, R, S, and T deflections (except S
y
) in orthogonal leads in women, and a greater incidence of initial counterclockwise rotation in the frontal plane QRS loop. Thus, sex differences show up better in the VCG than in the ECG. Separate normal 95 percentile limits for men and women are presented for all items with significant sex differences and pooled limits for VCG items without significant differences.
The Coronary Arteries in Coarctation of the Aorta
Authors: VLODAVER ZEEV , NEUFELD HENRY N.
Published: June 2012

The histological changes found in the coronary arteries in 15 patients with coarctation of the aorta have been described. Qualitative and quantitative studies were performed and the results compared with the findings of a matched control group of patients without heart disease.

Severe changes in the intima during early life and even the severe atheroma which appears in young persons are considered to be a reaction to coronary hypertension. The striking thickening of the media in the coronary arteries is also thought to be a reaction to the altered hemodynamic forces.

In coarctation of the aorta the coronary arteries are of greater than normal capacity, and it is suggested that this histological feature parallels the increased metabolic requirements of the left ventricle.
Role of the Capacitance and Resistance Vessels in Vasovagal Syncope
Authors: EPSTEIN STEPHEN E. , STAMPFER MORRIS , BEISER G. DAVID
Published: June 2012

Withdrawal of sympathetic tone to the veins resulting in peripheral pooling of blood has been suggested as an important factor contributing to the decrease in cardiac output and hence arterial pressure that occurs during vasovagal syncope. However, no measurements of venous tone during syncope have been reported. In the course of other studies on the circulatory effects of negative pressure below the iliac crests, and 80° head-up tilt, vasovagal reactions occurred in 10 subjects. Heart rate, central venous pressure, arterial pressure, forearm blood flow, forearm vascular resistance, and forearm or hand venous tone were measured. The typical vasovagal reaction could be divided into two phases. A gradual fall in arterial pressure signified the onset of phase I, during which forearm vascular resistance did not change significantly. The duration of phase I was highly variable. The onset of phase II was denoted by an abrupt fall in arterial pressure and heart rate and a decrease of 62% in forearm vascular resistance, from 36 to 14 mm Hg/ml/100 g/min. However, venoconstriction rather than venodilatation occurred in the forearm or hand veins. Since central venous pressure did not change prior to or during the onset of the reaction, it is unlikely that venodilatation occurred in other vascular beds. It is concluded that two of the major mechanisms responsible for the hypotension of vasovagal syncope initiated by orthostasis or lower body negative pressure are bradycardia and dilatation of the resistance vessels. In contrast, it appears that the venous bed, by constricting, tends to maintain filling pressure and thereby cardiac output, and thus works in an opposite direction.
Double Internal Mammary Artery-Myocardial Implantation
Authors: FAVALORO RENÉ G. , EFFLER DONALD B. , GROVES LAURENCE K. , FERGUSSON DAVID J. G. , LOZADA JOSÉ S.
Published: June 2012

A total of 248 double internal mammary artery-myocardial implantations have been performed at the Cleveland Clinic up to October 31, 1967. This report presents an analysis of the clinical experience with the first 150 patients. The majority of the patients were between 40 and 60 years of age. The overall hospital mortality was 9.3%. The lowest mortality rate (4.9%) was among patients between 51 and 60 years of age. The most common complication encountered in this series (22 patients) was atrial fibrillation. Acute myocardial infarction developed in 14 patients; all of them recovered with the usual medical treatment. All of the patients have been studied by Sones's technique of selective coronary angiography and left ventriculography. We believe that this is mandatory in the selection of patients for coronary artery operations. The postoperative evaluation shows significant clinical improvement in the majority, 116 patients. Thirty-one have undergone postoperative angiographic studies. Of 61 opacified arteries, 58 remained patent, and 37 showed definite communication with coronary arteries. We believe our present operative technique allows us to increase myocardial perfusion in any region of the left ventricle.
Operative Treatment in Idiopathic Hypertrophic Subaortic Stenosis
Authors: MORROW ANDREW G. , FOGARTY THOMAS J. , HANNAH HAMNER , BRAUNWALD EUGENE
Published: June 2012

Operations designed to relieve obstruction to left ventricular outflow were carried out in 25 patients with idiopathic hypertrophic subaortic stenosis (IHSS). All of the patients were symptomatic and 23 were in functional classes III or IV. Preoperatively, a systolic pressure gradient within the left ventricle was demonstrated in every patient (average, 102 mm Hg), and the average left ventricular end-diastolic pressure was 19 mm Hg. Six patients had pulmonary hypertension.

During cardiopulmonary bypass, the outflow tract of the left ventricle was exposed through an aortotomy. In five early patients only ventriculomyotomy was carried out, but in all subsequent operations myotomy was combined with a limited resection of the hypertrophied muscular tissue. One patient died, apparently of arrhythmia, on the eighth postoperative day, and another 8 months after operation following cerebral thrombosis. In two other patients complete heart block was produced, and they have implanted pacemakers.

Twenty-one of the 23 surviving patients have been followed for periods of 1 to 8 years; 15 are asymptomatic (class I). Six patients have mild residual limitation of activity (class II), but none has had congestive heart failure or syncope postoperatively, and only one experiences significant angina.

Left heart catheterization has been performed on one or more occasions after operation in all 21 patients. In 19, no systolic pressure gradient was evident within the left ventricle under resting conditions, and in the other two patients, gradients of 11 and 8 mm Hg were recorded. The left ventricular end-diastolic pressure was lower in 16 of the 17 patients in whom it was abnormally elevated preoperatively, and in nine of them it was normal. The pulmonary arterial pressure was normal postoperatively in all patients who had severe pulmonary hypertension.
Control of Postcardiac Surgical Tachycardias with Propranolol
Authors: MATLOFF JACK M. , WOLFSON STEVEN , GORLIN RICHARD , HARKEN DWIGHT E.
Published: June 2012

Twenty-two patients manifesting arrhythmias refractory to conventional therapy have been treated with propranolol 1 to 19 days after cardiac surgery.

Rapid control of ventricular response to supraventricular arrhythmias, abolition of ventricular irritability caused by digitalis excess, and frequent conversion of acute atrial fibrillation or flutter were attained.

Control of the arrhythmia was achieved in all but one instance. No significant side effects were encountered, although the potential risks of propranolol are stressed.

Propranolol appears to fill specific needs unsatisfied by standard therapy for arrhythmias developing after cardiac surgery.
Early Functional and Ultrastructural Recovery of Canine Cadaver Hearts
Authors: COPELAND JACK , KOSEK JON C. , HURLEY EDWARD J.
Published: June 2012

Simulation of sudden death in a potential heart graft donor was accomplished by producing acute anoxic arrest in canine hearts that were then maintained at cadaver temperature for periods of from 15 to 60 minutes prior to reperfusion with oxygenated blood. Functional recovery of reperfused hearts measured by contractile force was more rapid for hearts that had undergone shorter periods of anoxic arrest. The rates of recovery were nearly identical within the group for 15 to 25 minutes and for 30 to 45 minutes of anoxic arrest, but not for the 60-minute anoxic arrest group in which two of four hearts made no recovery at all.

Ultrastructural reactions to anoxic arrest were evident at 15 minutes and found to progress in a predictable manner as the duration of anoxia increased. Changes occurring during anoxic periods of up to 30 minutes were for the most part reversed within 1 hour of perfusion during which time characteristic nuclear, cytoplasmic, and mitochondrial "recovery patterns" were encountered. With a "pump-dog" preparation, these reperfused hearts were well kept for up to 7 hours. Anoxic arrest of 45 minutes or more produced ultrastructural changes that were less consistently reversed by reperfusion of 1 hour. The sensitivity of mitochondrial structure to anoxic arrest and reperfusion was demonstrated, and suggested that irreversible cell damage (i.e., cell death) in anoxia is due to mitochondrial failure. The techniques of perfusion and ultrastructural sampling employed in these experiments should prove useful in studying the effects of hypothermia, drug application and other measures in the preservation and restoration of isolated hearts.
Effects of Changing Body Position upon Improved Ventilation-Perfusion Relationships
Authors: CLAUSS ROY H. , SCALABRINI BERTRAND Y. , RAY JEFFERSON F. , REED GEORGE E.
Published: June 2012

Ventilation-perfusion relationships were studied in patients in the lateral and supine positions by monitoring blood gas tensions of peripheral arterial and pulmonary vein blood samples. West observed in erect subjects that the apex of the lung, while oxygenating less blood than the base, effected a higher P

o
o2

. This study shows that in patients not in the erect position the nondependent lung, lobe or portion of lung achieved higher P

o
o2

values than the dependent. The supine position was found to be associated with low peripheral arterial oxygen tensions. The simple maneuver of having the patient turn to a lateral position was found to increase oxygen tensions to satisfactory levels.
Effects of Reserpine Therapy on Cardiac Output and Atrioventricular Conduction During Rest and Controlled Heart Rates in Patients with Essential Hypertension
Authors: COHEN STAFFORD I. , YOUNG MELVIN W. , LAU SUN H. , HAFT JACOB I. , DAMATO ANTHONY N.
Published: June 2012

The effects of long-term reserpine therapy (1) on cardiac output during rest and induced atrial tachycardia and (2) on atrioventricular (A-V) conduction were examined in a group of eight men with previously untreated essential hypertension. The patients were studied before and after 20 to 205 days of reserpine therapy. All studies were performed in the cardiopulmonary laboratory with the patients supine. Heart rate was controlled with a transvenous pacing catheter and a battery-powered pacemaker. After therapy six of six patients had a fall in cardiac output with a statistically significant difference (
P
<0.001) between the means of paired pre-reserpine and reserpine cardiac outputs during both rest and paced tachycardia. At comparable heart rates, atrioventricular conduction increased in six of eight patients following reserpine, and a significant difference (
P
<0.05) was evident when the means of pooled paired pre-and post-reserpine A-V conductions were compared.

This study indicates that therapeutically administered reserpine in a hypertensive population (1) may significantly lower cardiac output at rest with no further decrease during induced atrial tachycardia, and (2) may increase A-V conduction and enhance second degree heart block during induced atrial tachycardia.
Iliofemoral Venous Thrombectomy
Authors: SMITH GARDNER W.
Published: June 2012

Experience with iliofemoral venous thrombectomy in 45 cases has been reviewed. The indications for this procedure have been presented, and only two absolute contraindications are recognized. Certain aspects of surgical technique and of postoperative care have been discussed, with emphasis on the use of local anesthesia, the balloon catheter, and early postoperative ambulation.

Results indicate that iliofemoral venous thrombectomy does relieve early morbidity and appears to be as successful as nonoperative management in the prevention of pulmonary embolism. Clinical improvement has been achieved in 76% of the entire group, and these results are influenced by both the preoperative duration of symptoms and the degree of success in removing the thrombus at operation. Of particular significance is a group of 14 patients followed for 2 or more years, only 14% of whom were afflicted by the sequelae of deep venous insufficiency. This finding provides encouraging support for the thesis that iliofemoral venous thrombectomy may ameliorate the late postphlebitic sequelae of deep venous thrombosis.
Differentiation of Ventricular Tachycardia from Junctional Tachycardia with Aberrant Conduction
Authors: EASLEY ROBERT M. , GOLDSTEIN SIDNEY
Published: June 2012

A case of regular tachycardia with an intraventricular conduction defect and possible retrograde P waves is reported. The condition was interpreted as being either ventricular tachycardia with 1 : 1 retrograde V-A conduction or an atrioventricular junctional tachycardia with aberrant intraventricular conduction. Atrial pacing resulted in normalization of intraventricular conduction as well as the production of fusion beats and allowed a definitive diagnosis of ventricular tachycardia. The use of atrial pacing as a diagnostic technique has not been previously discussed in the literature.
Cerebral Oxygen, Glucose, Lactate, and Pyruvate Metabolism in Stroke
Authors: MEYER JOHN S. , SAWADA T. , KITAMURA A. , TOYODA M.
Published: June 2012

Cerebral blood flow, oxygen, glucose, lactate, and pyruvate metabolism were measured in 13 subjects with completed stroke. Cerebral blood flow and oxygen consumption were reduced, glucose consumption and pyruvate production were normal, and lactate production was increased, suggesting a shift from aerobic to anaerobic cerebral glycolysis.

To test this hypothesis, cerebral blood flow and oxygen delivery were decreased by hyperventilation and increased by inhalation of 5% CO
2
in air. Hyperventilation decreased cerebral oxygen consumption (CMRO
2
) and increased cerebral lactate production. Inhalation of 5% CO
2
in air increased cerebral blood flow and oxygen delivery and increased both glucose and oxygen consumption. Relationships between reduction in PaCO
2
and cerebral venous PO
2
and increased cerebral lactate production were found.

Increasing cerebral blood flow by 5% CO
2
inhalation improved circulation and oxygen delivery to ischemic cerebral areas and improved oxygen and glucose metabolism in the majority of cases since these procedures do not alter CMRO
2
in normal persons. Intravenous injection of glucose increased cerebral glucose uptake but insulin did not.
Calcific Pulmonic Stenosis
Authors: ROBERTS WILLIAM C. , MASON DEAN T. , MORROW ANDREW G. , BRAUNWALD EUGENE
Published: June 2012

Seven patients are described in whom calcium deposits occurred in stenotic pulmonary valves. In five the calcific deposits were visible on chest roentgenogram. Survival into adulthood and severe pulmonic stenosis appeared to be the prerequisites for the development of large deposits of calcium in this valve.
Pathologic Anatomy of Dextrocardia and Its Clinical Implications
Authors: LEV MAURICE , LIBERTHSON RICHARD R. , ECKNER FRIEDRICH A. O. , ARCILLA RENÉ A.
Published: June 2012

This is a morphologic study of 41 cases of dextrocardia for the purpose of clarifying terminology and evaluating the clinical import of the morphologic data. Dextrocardias are classified as dextroversion, mirror-image dextrocardia, and mixed dextrocardia. When the atrial septum does not identify the atria, it was found possible to make the presumptive diagnosis of dextroversion or mirror-image dextrocardia. The mutual relations of the visceral situs with the atrial situs, the presence or absence of splenic abnormalities, the type of dextrocardia, and the systemic and pulmonic venous return were investigated, as well as the type of complex that is characteristic of each type of dextrocardia. The most important morphologic data useful for clinical application were found to be the position of the aortic and pulmonic annuli, the course of the pulmonary trunk, the entry of the inferior and superior venae cavae, and the course of the anterior descending coronary artery.
Effects of Acetylcholine on Regional Pulmonary Blood Flow in Patients with Mitral Stenosis
Authors: GLAZIER JON B. , DOLLERY COLIN T. , HUGHES JOHN M. B.
Published: June 2012

The effect of acetylcholine was studied on the region of increased vascular resistance at the lung bases in patients with mitral stenosis. The patients had moderate elevations of pulmonary artery pressure.

The distribution of blood flow and ventilation were measured in both lungs of 10 patients using radioactive xenon-133 and a scanning technique. Acetylcholine was then infused into one main pulmonary artery, and the distribution of blood flow and ventilation were measured again. One lung served as a control during the drug infusion. There was a small but significant increase in perfusion to the dependent lung zone during the drug infusion without a change in pulmonary artery pressure indicating localized vasodilatation. Relative underperfusion was still present during the acetylcholine administration which indicated that increased vasomotor tone was not the principal pathophysiological mechanism for the increased vascular resistance. There was a decrease in ventilation to the lower zone of the lung receiving acetylcholine.
Correlation of Myocardial Ultrastructure and Function
Authors: SONNENBLICK EDMUND H.
Published: June 2012

The electron microscopic structure of heart muscle and the ultrastructural basis of cardiac contraction have been reviewed. The relation between muscle length and developed tension has been explained in terms of the structure of the sarcomere, which is the basic unit of contraction. Using the derived length-tension curve of the sarcomere, developed tension has been attributed to the overlap of thick and thin filaments within the sarcomere, lending support to the "sliding" mechanism in heart muscle.

It has been shown that initial sarcomere length is a function of ventricular filling pressure and that this relation explains the normal limits of the heart as a pump, including: (1) the Starling mechanism whereby increased diastolic volume (EDV) engenders an increased stroke volume (SV), (2) the upper limits to ventricular filling pressure and volume, and (3) the normal range to the ventricular ejection fraction (SV/EDV). Further, ultrastructure helps to define the processes which occur with acute and chronic ventricular dilatation. In this regard, the importance of sarcomere dispersion and "fiber slippage," which may lead to disordered ventricular function, have been discussed.
Disturbances in Atrial Rhythm and Conduction Following the Surgical Creation of an Atrial Septal Defect by the Blalock-Hanlon Technique
Authors: HAMILTON SANDRA D. , BARTLEY THOMAS D. , MILLER ROBERT H. , SCHIEBLER GEROLD L. , MARRIOTT HENRY J. L.
Published: June 2012

Disturbances in atrial conduction or rhythm, or both, were found in 16 of 27 patients undergoing the surgical creation of an atrial septal defect by the Blalock-Hanlon technique. These included P-wave aberrations of intra-atrial block and ectopic atrial rhythm, A-V rhythm, A-V dissociation, sinus bradycardia, atrial flutter, escapecapture bigeminy, and atrial premature beats. Some of these were transient and occurred within 2 weeks after surgery. It seems likely that tissue trauma engendered by the clamp and resection of the atrial septum with possible injury to the internodal conducting pathways may be the genesis of these early postoperative disturbances. Of the eight cases with transient disturbances, six occurred in this period.

Later changes, such as intra-atrial block, sinus bradycardia, and atrial flutter, may be atttributed to changes in atrial size secondary to the postoperative pathophysiology. Digitalis intoxication and congestive heart failure cannot be excluded as contributory factors in either the early or the late disturbances.

It was not possible to correlate the incidence and nature of these disturbances with morbidity and mortality. In such severely ill, cyanotic infants, irregularities, however slight, may have altered cardiac function significantly and contributed to their deaths.
Endocardial Electrograms from Pacemaker Catheters
Authors: GORDON ALVIN J. , VAGUEIRO MARIA CELESTE , BAROLD S. SERGE
Published: June 2012

Proper placement of pacemaker catheters can be facilitated by recording endocardial electrograms from the catheters. These electrograms are also helpful in the investigation of pacemaker failure. Endocardial contact is indicated by S-T segment elevation. When bipolar catheters are used, these "contact currents" may be visible in electrograms from the tip or ring electrodes, or both.

Right ventricular cavity electrograms are characterized by their high voltage and are influenced by intraventricular conduction defects and acute myocardial infarction. Serial changes have been described indicating myocardial injury, infarction, and healing in the area underlying the catheter tip.
Constrictive Pericarditis
Authors: SOMERVILLE WALTER
Published: June 2012

Patients with untreated constrictive pericarditis sooner or later have ascites, edema, and pleural effusions. Unless these are treated, the patient soon becomes bedridden.

Treatment with a low-sodium diet, diuretics, and aspiration often allows a patient to live a semi-invalid life for 5 to 15 years and occasionally to survive to old age. However, the general tendency is toward gradual deterioration despite treatment. The course in children and young adults is more rapid and the effects of medical treatment less effective.

Pericardiectomy abolishes or greatly improves symptoms and signs in 60 to 85% of patients; the benefits are long lasting; and life expectation is increased. The operative mortality is in the range of 4 to 20%. Persistence of symptoms and signs after operation is attributable to one of the following factors: delayed hemodynamic adjustment, imperfect surgical relief, or myocardial changes. These changes may be the result of myocardial atrophy, other degenerative myopathies, or associated disease.

After an effective pericardiectomy, the hemodynamic fault may be completely corrected, but some residual abnormality can persist with symptomatic improvement. The electrocardiogram may improve, become completely normal, or remain unchanged; while electrocardiographic improvement is invariably associated with clinical improvement, the latter may occur despite persistence of an abnormal electrocardiogram. The heart size usually diminishes. Protein-losing gastroenteropathy is completely cured or greatly improved.
Permanently Implanted Transvenous Pacemakers
Authors: MCHENRY MALCOLM M. , NELSON CHARLES G. , HOPKINS DONALD M. , SMELOFF EDWARD A.
Published: June 2012

Three patients with complete heart block had a high resistance to electrical stimulation of the endocardium through transvenous pacemaker systems. One patient died; one needed reoperation for implantation of epicardial electrodes; and the third required a generator of higher current. The present enthusiasm for permanent transvenous implantation of pacemakers must be tempered somewhat by the knowledge that high endocardial resistance to pacing represents another cause of failure. Simple and rapid methods of determining the current necessary to stimulate the endocardium are available and should be used prior to permanent implantation of the generator. If a substantial margin of safety does not exist, one should consider substituting a pulse generator with greater output or an epicardial electrode system.
Relationship of Stroke to Other Cardiovascular Disease
Authors: FRIEDMAN GARY D. , LOVELAND DONALD B. , EHRLICH S. PAUL
Published: June 2012

The frequencies of prior cardiovascular abnormalities were compared in 117 stroke patients and 234 control subjects. All were residents of a retirement community who had been examined initially and followed in the local medical clinic before the strokes occurred. Cases and controls were matched for age, sex, length of residence, and blood pressure.

Prior coronary, rheumatic, and hypertensive heart disease were all more frequent in cases than in controls, as were cardiac enlargement, congestive heart failure, and digitalis therapy. There was a stronger association of stroke with atrial fibrillation than with other cardiac abnormalities, suggesting that atrial fibrillation in the elderly is an important precursor of stroke and should not be regarded lightly.

Aortic calcification and intermittent claudication were also more frequent among the stroke cases than the controls. Since the blood pressures of cases and controls were matched, the association of both cardiac disease and noncerebral atherosclerosis with stroke is independent of blood pressure and is not attributable to the fact that hypertension predisposes to all of these conditions.
Guanethidine-Resistant Hypertension
Authors: SANDLER G. , LEISHMAN A. W. D. , HUMBERSTONE P. M.
Published: June 2012

Resistance of hypertensive patients to large doses of guanethidine is seldom due to defective absorption of the drug, since the existence of adrenergic blockade can be demonstrated in these cases.

The effect on the blood pressure of intravenous phenoxybenzamine and norepinephrine, respectively, has been compared in groups of hypertensive patients resistant and responsive to guanethidine.

As both the hypotensive action of intravenous phenoxybenzamine, a peripheral antagonist of norepinephrine, and the pressor effect of norepinephrine infusion were more marked in patients resistant to guanethidine it seems likely that the maintenance of high blood pressure in these cases is due to enhanced sensitivity of the arterioles to endogenous norepinephrine. To combat this effect the therapeutic use of phenoxybenzamine appeared logical.

Phenoxybenzamine taken by mouth has been found by itself to be an unsatisfactory hypotensive agent but when used in combination with guanethidine has proved highly effective. The blood pressure of 13 out of 16 hypertensive cases previously resistant to guanethidine in high dosage has been controlled for periods of from 3 to 30 months after the addition of phenoxybenzamine.

When used in combination with guanethidine, phenoxybenzamine caused no side effects.
Uremic Pericarditis
Authors: BAILEY GEORGE L. , HAMPERS CONSTANTINE L. , HAGER EDWARD B. , MERRILL JOHN P.
Published: June 2012

Uremic pericarditis occurred in 41% of 83 patients admitted to the chronic dialysis program at the Peter Bent Brigham Hospital. In the vast majority of these patients the pericarditis was present before dialysis and cleared clinically after beginning therapy. Instances of pericarditis that developed during regular dialysis were associated with metabolic stress such as surgery or infection or inadequate dialysis. When the pericarditis failed to resolve the patients usually died with sepsis or had severe tamponade which necessitated early pericardiectomy. The two cases reported illustrate resorption of massive pericardial effusions with dialysis. The utility of percutaneous pericardial catheterization as a treatment for uremic pericardial tamponade is demonstrated.
Electromechanical Correlations in Hypertrophic Subaortic Stenosis
Authors: KLEIN MICHAEL D. , MATHUR VIRENDRA , LEVINE HAROLD D. , GORLIN RICHARD
Published: June 2012

Six of 14 patients with hemodynamically proven subaortic stenosis (SAS) showed electrocardiographic patterns consistent with myocardial infarction. Analysis of the 0.02-sec horizontal plane vector allowed discrimination between true myocardial infarction and SAS. In SAS this vector was shifted anteriorly and to the right consistent with septal hypertrophy and increased left-to-right early septal forces.

Cineangiographic studies of left ventricular contraction revealed a unique pattern also consistent with septal hypertrophy disproportionately greater than that of the ventricular free wall.

No correlation existed between maximal instantaneous vectorial voltage, and either the peak left ventricular pressure or the pressure gradient within the left ventricular outflow tract. Striking increases in vectorial forces in SAS may be related to dystrophic changes within the myocardial mass and may not be attributable to simple hypertrophy secondary to hemodynamic obstruction.
The Billowing Mitral Valve Leaflet
Authors: BITTAR NEVILLE , SOSA JULIO A.
Published: June 2012

Fourteen patients with billowing mitral valves have been studied. In 11 the abnormality was not accompanied by significant cardiac disability. In three, severe mitral insufficiency required mitral valve replacement. Pathological examination of the excised mitral valves showed myxomatous degeneration of mitral valve substance and chordae tendineae. Inhalation of amyl nitrite by the nine patients with late systolic murmurs resulted in a change from late systolic to pansystolic murmur in seven and to mid-systolic murmur in two. On the basis of the known effects of amyl nitrate, this response gives support to the concept that the critical pathogenetic factor is the degree of elongation of chordae tendineae.
Hypolipidemic Effect of Polyvinylpyrrolidone in Man
Authors: SANBAR SHAFEEK S. , SMET GUIDO
Published: June 2012

Intravenous infusion of 500 ml of 6% polyvinylpyrrolidone (PVP, average molecular weight 40,000) in isotonic saline solution daily for 2 days induced prompt and significant reductions in serum cholesterol and triglyceride concentrations in eight hyperlipidemic patients. Mean maximal decrements in serum cholesterol and triglyceride were 29% and 28% below control values, respectively, occurring 5 days after infusion of PVP. Mean values for hematocrit and total serum protein concentration were slightly decreased following PVP infusion, but there were no changes in percentage composition of serum proteins, blood sugar, serum sodium and potassium, body weight, and blood pressure. The hypolipidemic effect of PVP persisted beyond the period of plasma volume expansion, as demonstrated by measurement of the plasma volume isotopically and by long-term follow-up in five of the patients.
Quantitative Angiocardiography
Authors: KENNEDY J. WARD , TWISS R. D. , BLACKMON J. R. , DODGE H. T.
Published: June 2012

Quantitative angiocardiographic techniques have been used to determine left ventricular volume and mass in 100 patients with isolated aortic valve disease. The patients were divided into three groups: aortic stenosis (AS), 22 patients; aortic regurgitation (AR), 38 patients; and combined stenosis and regurgitation (AS+AR), 40 patients. The distribution of left ventricular volume and mass and their relationship to standard intracardiac pressure and flow determinations are presented for each group in order to define the hemodynamic and functional characteristics of the left ventricle in these patients. Mean values for end-diastolic volumes (EDV) in the three groups were AS=85 ml/m
2
, AS+AR=143 ml/m
2
and AR=197 ml/m
2
. Mean values for ejection fraction (EF=SV/EDV) were similar in the three groups, AS=61%, AR= 55%, AS+AR=58%.

Left ventricular mass (LVM) was smaller in AS, mean=167 g/m
2
, and similar in AR, mean=232 g/m
2
, and AS+AR, mean=235 g/m
2
. Left ventricular filling pressure (LVEDP) was correlated with EDV in AS, r=0.45,
P
<0.05, and AS+AR, r=0.51,
P
<0.001, but not in AR. A similar relationship was seen between LVEDP and EF. The arteriovenous oxygen difference correlated well with EF in AS, r=–0.76.
P
<0.001. This relationship was weaker in AS+AR, r= –0.45,
P
<0.01, and AR, r=–0.45,
P
<0.01. Correlations were also present between increased LVM and elevated LVEDP and increased LVM and decreased EF in patients with AS and AS+AR.