bluuebunny/crossref_metadata_2025 huggingface dataset:
Cardioversion after Mitral Valve Operations
Authors: KAHN DONALD R. , KIRSH MARVIN M. , FERGUSON PAULINE W. , SLOAN HERBERT
Published: June 2012

When atrial fibrillation is converted to normal sinus rhythm following the surgical repair of mitral valve disease, the normal pattern is more likely to persist if the preoperative diagnosis is mitral stenosis, atrial fibrillation has been established for less than 3 years, and results of the operation are excellent. To determine the specific reasons for recurrence of fibrillation, however, and to devise ways of preventing these recurrences will require further investigation of both pathogenic mechanism and therapeutic agents.

In 55 patients with mitral valve disease and atrial fibrillation operated upon at The University of Michigan Medical Center from 1963 to 1966, normal sinus rhythm was established after operation in 43 but maintained in only 20. Most recurrences of atrial fibrillation appeared during the first 3 months after the heart operation. The time lapse between operation and cardioversion did not affect the conversion rate or maintenance. Cardioversion was more often successful after valvuloplasty than after valve replacement, but the maintenance rate was the same.
Cardiac Tamponade due to Hypertonic Contrast Medium in the Pericardial Sac Following Cineangiography
Authors: POPPER ROBERT W. , SCHUMACHER DAVID , QUINN CHARLES H.
Published: June 2012

Relatively small amounts of contrast media reaching the pericardial sac can cause acute cardiac tamponade. The mechanism of this complication is on the basis of the hyperosmolarity of these angiographic media, resulting in the further accumulation of large amounts of fluid in the pericardial sac. Active bleeding due to possible perforation has probably not been a major factor in the cases reported. The appearance of contrast medium in the pericardial sac should alert the cardiac catheterization team to the possibility of impending severe cardiac tamponade, and pericardiocentesis should be prepared for immediately. Thoracotomy is probably not necessary in the majority of cases.
Surgical Repair of a False Aneurysm of the Left Ventricle Resulting from a Separation Between the Aorta and the Heart
Authors: WELDON CLARENCE S.
Published: June 2012

In the case of at 44-year-old Negro man with lupus erythematosus reported, a rapidly expanding mass had developed in the region of the left ventricle. Surgical exploration revealed a false aneurysm arising from a defect at the base of the heart. The defect is interpreted as a separation of the aorta from the heart in the region of the left coronary cusp of the aortic valve. Surgical repair is outlined and illustrated. The relationship of this defect to annular subvalvular aneturysm occurring in African Negroes is discussed.
Further Observations on the Effect of Hydrogen Ion on the Pulmonary Circulation
Authors: HARVEY RÉJANE M. , ENSON YALE , BETTI RUDOLFO , LEWIS MILENA L. , ROCHESTER DUDLEY F. , FERRER M. IRENÉ
Published: June 2012

The effects of an acutely induced and modest increase in blood hydrogen-ion concentration on pulmonary hemodynamics were studied in 15 patients with obstructive lung disease. Pulmonary arterial pressure rose when the blood hydrogen-ion concentration increased; this change was greater when the arterial oxyhemoglobin saturation was lower than 91%. The pressor response was independent of change in cardiac output, pulmonary blood volume, and left veno-atrial pressure and is ascribed to pulmonary arterial vaso-constriction. Increased concentration of hydrogen ion is a factor in the production of pulmonary hypertension in patients with chronic obstructive pulmonary disease. Since infusion of acid produced a marked increase in ventilation, the effects of voluntary hyperventilation on pulmonary hemodynamics were studied in three patients with similar pulmonary diseases. In these subjects pulmonary arterial pressure fell as ventilation was increased by a degree comparable to that which occurred during the infusion of acid.
Studies of Cardiopulmonary Blood Volume
Authors: LEVINSON GILBERT E. , FRANK MARTIN J. , NADIMI MANOUCHEHR , BRAUNSTEIN MILTON
Published: June 2012

The measurement of ventricular end-diastolic volume from washout of an indicator requiring blood sampling was studied in a heart model and in dogs and applied to the left ventricle in 34 human subjects. The model, under the ideal conditions of constant ejection fraction, uniform cycle length, and complete or nearly complete mixing, demonstrated that dye dilution accurately measures chamber volumes if the distorting effects of catheter sampling are obviated by clearance of the sampling system at least once per two cardiac cycles. The studies in dogs and in human beings demonstrated that the required sampling conditions are achievable.

In 11 normal human subjects, left ventricular end-diastolic volume ranged from 72 to 99 with a mean of 82 ± 12 ml/m,
2
end-systolic volume, from 22 to 60 with a mean of 37 ± 11 ml/m,
2
and ejection fraction, from 0.39 to 0.71 with a mean of 0.55 ± 0.08. These measurements are in substantial agreement with results by radiocardiography and thermal dilution and are systematically, but only slightly, higher than results by quantitative angiocardiography.

In six considerably older patients with chronic pulmonary disease, cardiac output was normal for the age group but ejection from a ventricle of normal size was reduced. In 12 subjects with pure mitral stenosis and in five with atrial septal defect, end-diastolic volume and ejection fraction were significantly reduced.

End-diastolic volume correlated with stroke volume in all groups and in the series as a whole, but a correlation between end-diastolic volume and cardiac output was demonstrated only in the patients with mitral stenosis or atrial septal defect. This suggests that chronic restriction to ventricular filling results in decreased end-diastolic volume. The absence of a significant correlation between end-diastolic volume and end-diastolic pressure indicates that variation in ventricular compliance precludes reliance on end-diastolic pressure as a valid index of end-diastolic fiber length.
Relation of Heart Rate and Systolic Blood Pressure to the Onset of Pain in Angina Pectoris
Authors: ROBINSON BRIAN F.
Published: June 2012

Arterial pressure was recorded directly and continuously in 15 patients with angina pectoris while pain was repeatedly induced by exercise of various types and severity. In every case, the precipitation of angina could be consistently related to the level reached by the product of heart rate and systolic blood pressure (corrected when necessary for changes in ejection time). This relationship persisted even when there were large variations in the type, intensity, and duration of the exercise and was also maintained in a patient in whom spontaneous and emotional episodes of pain were observed. A substantial improvement in exercise tolerance occurred in one patient and this was completely accounted for by a reduction in the circulatory response to exercise.

It was concluded that the precipitation of angina is normally the result of a rise in the work of the myocardium to a critical level which is essentially fixed in each patient. The varying ease with which pain is provoked on different occasions can usually be explained by variations in circulatory response to the precipitating stress.
Muscular Subaortic Stenosis
Authors: WIGLE E. DOUGLAS , MARQUIS YVES , AUGER PIERRE
Published: June 2012

Two types of intraventricular pressure difference within the left ventricle of man are described. The first type was encountered in eight consecutive patients with muscular subaortic stenosis in whom the outflow tract pressure distal to the stenosis was low and equal to the aortic systolic pressure, whereas all ventricular pressures proximal to the stenosis, including that just inside the mitral valve (the initial inflow tract pressure) were high. The second type was encountered in five of 10 patients with nonobstructive cardiomyopathy when a cardiac catheter was advanced to the left ventricular wall where it became entrapped or imbedded in cardiac muscle in systole and recorded a high ventricular pressure that was believed to reflect subendocardial intramyocardial tissue pressure. In this second type of intraventricular pressure difference, the initial inflow tract pressure, as well as all truly intracavitary pressures, were low and equal to the aortic systolic pressure.

By defining two types of intraventricular pressure difference, the recent controversy as to the nature of such pressure differences in man may be resolved, and the obstructive nature of muscular subaortic stenosis reaffirmed.
Takayasu's Arteritis
Authors: NAKAO KIKU , IKEDA MASAO , KIMATA SHIN-ICHI , NIITANI HIROKAZU , MIYAHARA MITSUO , ISHIMI ZEN-ICHI , HASHIBA KUNITAKE , TAKEDA YOSHIYUKI , OZAWA TOSHIO , MATSUSHITA SATORU , KURAMOCHI MORIO
Published: June 2012

The manifestations of Takayasu's arteritis of the aorta were studied in 84 patients. The extent of the involvement of the aorta was classified on aortographic examination in 54 patients and from the clinical manifestations in 30. Involvement of the aorta was classified as: (1) arch type in 47 cases; (2) extensive type (whole aorta and its branches involved) in 27 cases; and (3) descending thoracic and abdominal type (only descending thoracic and abdominal aortas involved) in 10 cases. The three types resembled one another in clinical manifestations and laboratory findings except for ischemic signs which varied with the type of lesion and a slight difference in the ratio of male to female patients. Generalized, cardiac and pulmonary symptoms were noted by about two thirds of the patients in the early stage. About one third complained of local pain. The erythrocyte sedimentation rate and C-reactive protein were high values during the active stage of this disease. The hemagglutination test using tannic acid-treated erythrocytes was positive in five of seven cases. It is not clear yet that circulating anti-arterial antibodies are the direct cause of Takayasu's arteritis.
Reciprocal Beating from Artificial Ventricular Pacemaker
Authors: KASTOR JOHN A. , DESANCTIS ROMAN W.
Published: June 2012

A case is reported of reciprocal beating induced by a transvenous ventricular pacemaker inserted because of permanent sinus arrest. The mechanism of this finding is discussed.
Cor Triatriatum
Authors: JORGENSEN CHARLES R. , FERLIC RANDOLPH M. , VARCO RICHARD L. , LILLEHEI C. WALTON , ELIOT ROBERT S.
Published: June 2012

A follow-up report on the first patient with cor triatriatum to undergo successful surgical treatment is presented. A second procedure was necessary 9½ years later because of stenosis of the initial surgically created orifice in the anomalous diaphragm. A review and ananalysis have been made of 17 cases from the literature reporting successful operations for this lesion. Total excision of the accessory septum utilizing cardiopulmonary bypass is presently the appropriate surgical treatment of this entity. Preoperative and postoperative hemodynamic data are discussed. Recognition and correction of this defect are emphasized in order to avoid permanent pulmonary vascular changes attended by a relatively fixed cardiac output.
Protection from Digitalis Toxicity with the Prophylactic Use of Diphenylhydantoin Sodium An Arrhythmic-Inotropic Dissociation
Authors: HELFANT RICHARD H. , SCHERLAG BENJAMIN J. , DAMATO ANTHONY N.
Published: June 2012

Diphenylhydantoin sodium (Dilantin) given prophylactically increased the dose of digitalis necessary to produce toxicity by 72 to 224%. At constant heart rates, pretreatment with diphenylhydantoin sodium did not alter the elevation of rate of rise of left ventricular pressure produced by the glycoside.

Two implications have been drawn from these findings. First, the inotropic and arrhythmic actions of digitalis can be dissociated, since diphenylhydantoin sodium seems specifically to counteract the electrophysiological actions of the glycoside. Second, pretreatment with diphenylhydantoin sodium significantly widened the "toxic-therapeutic" ratio of digitalis. This, therefore, may have important clinical applications.
Antihypertensive Properties of Furosemide
Authors: DAVIDOV MICHAEL , KAKAVIATOS NIKOS , FINNERTY FRANK A.
Published: June 2012

The antihypertensive properties of single doses of furosemide were evaluated in 113 patients. Doses over 120 mg consistently produced a fall in arterial pressure whereas smaller doses did not. Thus 20 of 22 patients (90%) who received more than 120 mg had a 26 ± 6% average reduction in mean arterial pressure. The hypotensive action began in 30 to 45 minutes, the nadir of the decrease occurred between 2 and 2½ hours, and the hypotension usually lasted 10 to 12 hours. Repeated weekly doses of furosemide over a 2-month period in six patients were not associated with development of drug resistance. The antihypertensive properties of doses of furosemide of more than 120 mg seemed to be of about the same potency as ethacrynic acid. The antihypertensive effect of high doses of furosemide did not seem to be related to the diuretic effect or to the decrease in plasma volume.

These studies have demonstrated that doses of furosemide of more than 120 mg consistently decreased arterial pressure. The usefulness of this agent in the long-term management of hypertension remains to be determined.
SPECIAL ARTICLE
Authors: VON DER GROEBEN J.
Published: June 2012

The diagnostic classification of the ECG waveform can be performed either by visual inspection of the electrocardiogram or by a set of mathematical-statistical decision rules programmed into a computer. It can be demonstrated that if the visual inspection technique is used, the 12-lead ECG will be superior to three scalar orthogonal vectorcardiographic leads. Plane projection vector loops lack accurate data display. If computer techniques are used, suitable decision regions of the instantaneous heart vector will provide accurate decision rules on a three-lead system. Neither the 12-lead system nor the three-orthogonal lead system makes use of all the information available on the body surface. A detailed electrical torso mapping would be required if this information proves to be of diagnostic significance.

Misclassification in electrocardiographic diagnosis may be due to (1) failure of electrical events to reflect hemodynamic, anatomic, or biochemical changes; (2) loss of information between the cardiac generator and the body surface; (3) inadequate data display; (4) inadequate mathematical-statistical decision regions; and (5) insufficient number of teaching samples or inadequate independent evidence.
Exercise and Intermittent Claudication
Authors: SKINNER JAMES S. , STRANDNESS D. EUGENE
Published: June 2012

Five men with arteriosclerosis obliterans (ASO) underwent a 3 to 8-month physical training program. The systolic pressure at the ankle (AP) before and after exercise, maximal walking time (MWT), and time of onset of claudication pain (CPT) were recorded on 4 different days. After training, these measurements were repeated on 3 different days. In addition, each subject was retested at his initial MWT.

There were significant increases in resting AP levels of three subjects, in CPT and MWT of all five subjects and in the postexercise AP levels of all five subjects. Pain diminished or disappeared for varying periods of time while four of the subjects were walking. These data signify that there was a significant increase in collateral circulation at rest, during or after exercise, or both, improving the blood supply to the obstructed leg.
The Effects of Mitral Regurgitation on the Pattern of Instantaneous Aortic Blood Flow Clinical and Experimental Observations
Authors: ELKINS RONALD C. , MORROW ANDREW G. , VASKO JOHN S. , BRAUNWALD EUGENE
Published: June 2012

Instantaneous ascending aortic blood flow was recorded at operation in five patients with severe, pure mitral regurgitation, and in nine dogs in which mitral regurgitation was produced experimentally under controlled conditions. In both the patients and the experimental animals, the pattern of aortic flow was abnormal during mitral regurgitation: peak flow occurred early, the percentage of total forward flow was abnormally high during the first half of the ejection period and abnormally low during the last quarter. When stroke volume, heart rate, and aortic pressure were maintained constant, mitral regurgitation also resulted in increases in peak flow, mean ejection rate, and maximum acceleration of flow. These abnormalities of the aortic flow patterns are attributable to inability of the ventricle to sustain forward ejection during late systole in the presence of severe regurgitant flow through the mitral valve.
Distribution of Arterial Lesions Demonstrated by Selective Cinecoronary Arteriography
Authors: PROUDFIT WILLIAM L. , SHIREY EARL K. , SONES F. MASON
Published: June 2012

The distribution of obstructions exceeding 30% of the normal diameter of the lumen of one or more major coronary arteries was studied in 627 of 1,000 patients who had selective cinecoronary arteriograms. An additional 99 patients had lesser degrees of narrowing, and in the arteriograms of 274 patients, normal arteries were demonstrated. An average of 2.0 lesions resulting in at least 50% luminal narrowing of major arteries was found per patient. The anterior descending coronary artery was involved slightly more frequently than were other vessels. More than 75% of the symptomatic patients had 90% or more obstruction of at least one vessel, and more than 50% had total occlusions of one or more vessels. A single major artery was the site of obstruction exceeding 30% of the luminal diameter in 131 patients (20.9% of the 627 patients), and in 43 of these (6.9%) the other arteries appeared to be entirely normal. Severe involvement of single arteries was most frequent in patients who had myocardial infarction without angina pectoris or in those who had rest pain only. No pattern of arterial involvement was pathognomonic of a clinical syndrome.
Monitoring Cerebral Blood Flow, Oxygen, and Glucose Metabolism
Authors: MEYER JOHN S. , GOTOH F. , AKIYAMA M. , YOSHITAKE S.
Published: June 2012

More accurate methods for monitoring cerebral blood flow, oxygen, and glucose metabolism with results of their application in human volunteers are described.

Subjects with various types of cerebral vascular disease showed decreased cerebral blood flow and oxygen and glucose metabolism but anaerobic glycolysis appeared to be increased. Inhalation of 100% oxygen decreased anaerobic glycolysis, and mixtures of oxygen, 5% CO
2
plus oxygen, 5% CO
2
plus air, and hyperventilation all showed that cerebral vascular reactivity is reduced in cerebrovascular disease. Nevertheless, inhalation of 5% mixtures of CO
2
in air or oxygen significantly increased cerebral blood flow. Inhalation of 5% CO
2
plus oxygen significantly increased cerebral oxygen consumption in cerebrovascular disease within 10 minutes of its institution. The depression of cerebral glucose metabolism and oxygen consumption appears to be amenable to rapid improvement in some subjects with stroke. Intravenous administration of nylidrin hydrochloride decreased cerebral vascular resistance but did not increase cerebral blood flow or metabolism, presumably by autoregulation. Intravenous injection of 100 ml of low molecular-weight dextran increased cerebral blood flow and oxygen consumption but not to the level of statistical significance. A case of brain-stem ischemia showed a large increase of cerebral blood flow, oxygen metabolism, and glucose consumption after surgical reconstruction of the left vertebral artery accompanied by clinical recovery.
Long-Term Results of Endarterectomy of the Internal Carotid Artery for Cerebral Ischemia and Infarction
Authors: HEYMAN ALBERT , YOUNG W. GLENN , BROWN IVAN W. , GRIMSON KEITH S.
Published: June 2012

The immediate and long-term results of carotid endarterectomy for treatment of acute cerebral ischemia or infarction were studied in 95 patients who were observed for an average period of 40 months after the surgical procedure. The operation resulted in death for 12 patients and worsening of the neurological deficit in six others. During the follow-up period, there were 22 additional deaths, most of which were caused by myocardial infarction or other complications of systemic atherosclerotic vascular disease.

The significant factors adversely affecting the prognosis of these patients consisted of severe electrocardiographic abnormalities, the presence of bilateral carotid occlusive lesions, cerebral infarction prior to endarterectomy, and the age of the patient.

Following endarterectomy only five patients were observed to have recurrent attacks of transient cerebral ischemia which were few in number and stopped spontaneously. Recurrent cerebral infarction developed in only seven patients, six of whom had unsuccessful or incomplete removal of the carotid occlusive lesions. Although this low incidence of recurrent ischemia and infarction seems to be evidence for the therapeutic value of carotid endarterectomy, further observations on a comparable group of patients treated nonsurgically are needed to support this conclusion.
Influence of Hypertension on the Hemodynamic Response to Exercise
Authors: AMERY ANTOON , JULIUS STEVO , WHITLOCK LEIGH S. , CONWAY JAMES
Published: June 2012

Sixty-one asymptomatic hypertensive patients from 19 to 68 years of age were subjected to a progressive exercise test on a cycle ergometer. A decline in maximal oxygen consumption and cardiac output and an increase in systolic blood pressure were observed with age. These findings were similar to those observed in normal subjects. In the middle-aged (35 to 49 years) and older subjects (50 to 60 years), the systolic pressure showed a greater increase with exercise than in normals of their age, but this did not apply to subjects aged 19 to 34 years. The cardiac response to exercise was normal at rest and at all levels of exercise in the middle-aged group, but the oldest group showed a reduced maximum cardiac output. In the youngest age group, cardiac output was normal at rest but fell below normal at all levels of exercise.

Maximal voluntary oxygen consumption and cardiac output were significantly reduced with increasing severity of hypertension.
Incomplete Left Bundle-Branch Block
Authors: LEIGHTON RICHARD F. , RYAN JOSEPH M. , GOODWIN RICHARD S. , WOOLEY CHARLES F. , WEISSLER ARNOLD M.
Published: June 2012

The direction of the initial 20 to 30 msec forces of multiple unipolar and transseptal bipolar intraventricular electrocardiograms was examined in five patients with and five without incomplete left bundle-branch block (LBBB) and in one patient with complete LBBB. The data obtained were consistent with preservation of the normal left-to-right and apex-to-base direction of septal depolarization in patients with apparent, incomplete LBBB. Furthermore, no evidence of electromechanical delay in the left ventricle could be ascribed to this conduction defect. Until the minute details of normal and abnormal human septal excitation become known, it is suggested that the more descriptive and less mechanistic term "initial force abnormality" be substituted for "incomplete LBBB."
Dynamic Analysis of Heart Sounds in Right and Left Bundle-Branch Blocks
Authors: ORAVETZ JAN , WISSNER STANLEY , ARGANO BEATRICE , LUISADA ALDO A.
Published: June 2012

A clinical, electrocardiographic, phonocardiographic, and arteriographic study was made of 20 normal subjects, 20 patients with right bundle-branch block (RBBB) and 20 patients with left bundle-branch block (LBBB). Ventricular asynchronism was documented in nearly all cases of bundle-branch block by the behavior of the arterial pulse and the heart sounds. The first heart sound was of normal duration in all cases and usually had the normal number and position of its three components. The first sound had a normal relationship with the QRS component of the electrocardiogram in RBBB, but its onset was markedly delayed in LBBB. This fact confirms the exclusive left-sided origin of the first sound. The third (or ejection) component of the first sound had a greater delay in LBBB, due to intraventricular block, and this delay was closely related to that of the carotid pulse rise. Reversed splitting of the second sound in LBBB was common.
The Coagulant and Thrombogenic Properties of Human Atheroma
Authors: LYFORD CHARLES L. , CONNOR WILLIAM E. , HOAK JOHN C. , WARNER EMORY D.
Published: June 2012

Suspensions of gruel from severely atherosclerotic human aortas and coronary arteries were tested in several coagulation systems. The atheromatous material shortened the clotting time of normal whole blood and plasma and accelerated thrombus formation time in the Chandler apparatus. Normal human platelets in platelet-rich plasma were aggregated by the atheromatous gruel. Aggregation did not occur when the gruel was added to platelet-rich plasma from a patient with a severe factor XII (Hageman) deficiency. The intravenous injection of atheromatous plaque suspensions into rats caused thrombocytopenia, shortening of the whole blood clotting time, and thrombosis.

Coagulation of blood from patients with classical hemophilia, with Hageman factor deficiency, and with coumarin-induced anticoagulant effect was accelerated by the addition of the atheromatous gruel. Blood from patients given heparin, however, largely retained its anticoagulant activity.

Atheromatous material from both aortic and coronary arteries behaved similarly in the systems tested. The coagulant and platelet clumping properties of atheromatous plaques may be related to their content of fatty acids, phospholipids, collagen, or thromboplastin.
Atrial Flutter Associated with Isolated Pulmonic Stenosis
Authors: STERN SHLOMO , BORMAN JOSEPH B.
Published: June 2012

Two adults with severe pulmonic valvular stenosis and atrial flutter are presented. This arrhythmia is apparently a rare complication of this particular form of congenital heart disease. In both cases surgical correction was achieved with the aid of total body perfusion. At the time of surgery, significant tricuspid insufficiency was discovered in both cases. Although the tricuspid valve was not repaired, insufficiency of this valve was not evident postoperatively. Cardioversion, applied at a different stage in each, terminated the atrial flutter in both patients. Sinus rhythm has been maintained for almost 2 years without drug therapy. The optimal time for cardioversion in such cases is discussed.
Computer Search for Electrocardiographic Lead Directions to Optimize Diagnostic Differentiation
Authors: BATCHLOR CHARLES D. , BERSON ALAN S. , NAVAL I. ALZONA , PIPBERGER HUBERT V.
Published: June 2012

A computer was programmed to search for electrocardiographic lead directions, yielding optimal separations between records obtained from 500 normal subjects and 422 patients believed to have either left ventricular hypertrophy (LVH) or right ventricular hypertrophy (RVH). The majority of the patients with RVH (86%) exhibited chronic pulmonary disease with severe pulmonary insufficiency where development of chronic cor pulmonale was assumed. Autopsy confirmation of RVH or LVH was obtained in 38 cases. The diagnoses in the remainder were based on history and physical findings.

Resolved leads derived from a corrected orthogonal system were tested for discrimination of the three groups. The number of false-positive and false-negative classifications was kept approximately equal. To simplify record analysis, the number of QRS measurements necessary for interpretation was limited to a single one.

The optimal lead direction to separate normal records from those obtained in patients with LVH had an azimuth angle of 306° and an elevation angle of –58°. The lead for separation of cases of RVH was almost identical with horizontal lead X. Comparison between results obtained with optimized leads and 12-lead records showed approximately equal performance for LVH when sensitivity and specificity were kept the same. These results were based on up to eight measurements from 12 leads as compared to one measurement in a single lead.

The diagnostic performance of optimized leads exceeded that of the 12-lead electrocardiogram when a set of the most commonly used criteria for LVH and RVH recognition was used.

A simple analog device for obtaining optimal leads was designed which can be attached to conventional single-channel electrocardiographs.

The feasibility of directional lead optimization by orthogonal lead resolution could be demonstrated with concomitant simplification of record analysis and greater ease in record taking.
Tilt Test for Investigating a Neural Component in Hypertension
Authors: FROHLICH EDWARD D. , TARAZI ROBERT C. , ULRYCH MILOS , DUSTAN HARRIET P. , PAGE IRVINE H.
Published: June 2012

Hemodynamic changes associated with diastolic hypertension were investigated using 50° head-up for 52 untreated hypertensive patients not in cardiac failure, and for 17 normotensive subjects. Normals responded to tilt with±10 mm Hg change in mean arterial pressure. Twenty-four hypertensives responded similarly; the remainder had either orthostatic hypertension (18) or orthostatic hypotension (10). During tilt, cardiac output reduction of each hypertensive group was greater than normal, but only orthostatic hypertensives responded with exaggerated increase in peripheral resistance. When supine, orthostatic hypotensives had lower cardiac indices and higher peripheral resistances than orthostatic hypertensives. When the three hypertensive groups were compared with respect to clinical features, orthostatic hypertensives had the least severe vascular disease; orthostatic hypotensives were the opposite extreme, and normal responders were intermediate. These findings suggest that neurogenic activity is highest in mild hypertension and in the more severe forms of the disease, it is least.
Cerebrovascular Disease in an Elderly Population
Authors: CUTLER JOHN L.
Published: June 2012

A sample of residents of a retirement community was investigated for symptoms and signs thought to be premonitory of stroke, as the initial step in a study of factors that predict the occurrence of stroke. Persons who had experienced a prior stroke reported a number of symptoms more frequently than did persons who had not had a stroke. The stroke group had a higher prevalence of cervical bruits, higher mean blood pressures, and significantly more abnormal electrocardiograms. There were no differences for cholesterol or hemoglobin.
Calcified Left Atrial Myxoma Simulating Mitral Insufficiency
Authors: PENNY JOHN L. , GREGORY JOHN J. , AYRES STEPHEN M. , GIANNELLI STANLEY , ROSSI PLINIO
Published: June 2012

In the atypical case presented, a calcified myxoma of the left atrium simulated isolated mitral insufficiency. Unique hemodynamic and phonocardiographic events were recorded. A notch in the upstroke of the left ventricular pressure tracing during isometric contraction occurred simultaneously with an ejection sound, which fused with the first heart sound, and with an abrupt decrease in ventricular volume as the tumor was ejected from the ventricle. A similar notch in the downstroke of the ventricular pressure tracing was most likely due to the abrupt increase in ventricular volume as the tumor descended into the left ventricle. A third heart sound was present which was identified as a ventricular diastolic gallop and was differentiated from a mitral opening snap by simultaneous pressure tracings.
A Complication of Valve Replacement by a Caged-Lens Prosthesis
Authors: EDGETT J. W. , NELSON W. P. , HALL R. J. , JAHNKE E.J. , AABY G. V.
Published: June 2012

Five of 37 patients undergoing valve replacement with a "caged-lens" prosthesis demonstrated intermittent insufficiency of the prosthesis. Four of these patients had mitral valve replacement, three of whom had uncorrected aortic insufficiency. Cineradiography showed tilting of the prosthetic lens and impingement within the cage in an oblique position.
The Measurement of Glomerular Filtration Rate and Effective Renal Plasma Flow in Man by Iothalamate
125
I and Iodopyracet
131
I
Authors: ELWOOD CHARLES M. , SIGMAN EUGENE M.
Published: June 2012

In 21 patients, 90 simultaneous renal clearances of inulin and sodium iothalamate
125
I, and para-amino-hippuric acid (PAH) and iodopyracet
131
I were determined by a constant infusion technique. The activities of iothalamate
125
I and iodopyracet
131
I were determined simultaneously in a dual-channel scintillation counter. The concentrations of inulin and PAH were determined by standard chemical techniques. The ratio of iothalamate
125
I to inulin clearance ranged from 0.93 to 1.09 with a mean of 1.00. The ratio of iodopyracet
131
I to PAH clearance varied from 0.86 to 1.04 with a mean of 0.96. The chemical determination of PAH and inulin required approximately 8 hours of technician time as compared with 30 minutes by the radioactive technique. The determination of the renal clearances of iothalamate
125
I and iodopyracet
131
I is an accurate and time-saving technique for the measurement of glomerular filtration rate and effective renal plasma flow.
Radiological Aspects of Heart Muscle Disease in Nigerian Adults
Authors: COCKSHOTT W. PETER , THORPE G. J. , IKEME A. C.
Published: June 2012

A congestive cardiomyopathy, known locally as heart muscle disease, accounts for 32% of the cases of cardiovascular disease seen at University College Hospital, Ibadan, Nigeria.

Following a brief outline of the clinical picture and necropsy findings, the radiological features of the disease are described. Thirty-four cases were studied, and angiography was performed in 13. In the acute stage of the disease there was a generalized, globular, cardiac enlargement, and cardiac movements, especially of the left border of the heart, were reduced. Pulmonary venous congestion was invariably present and pleural effusions occurred frequently. Ventricular angiography demonstrated an enlarged chamber with little change in size and shape throughout the cardiac cycle, and persistence of contrast. Mitral incompetence was present in some cases. The value of angiography in differential diagnosis in emphasized.
Mechanisms of Angina in Aortic Stenosis
Authors: FALLEN ERNEST L. , ELLIOTT WILLIAM C. , GORLIN RICHARD
Published: June 2012

The pathophysiology of cardiac pain in pure aortic stenosis has primarily been ascribed to an augmented left ventricular demand outstripping energy supply. This report provides evidence that not only is the energy demand increased but the supply in terms of coronary vascular reserve may be impaired, particularly in response to stress. Hemodynamic and coronary circulatory changes were studied in 18 patients with aortic stenosis during standard isoproterenol infusion. It was not possible to differentiate any patient with or without angina pectoris or patients with or without coronary artery disease on a basis of change in any measure of left ventricular dynamics. On the other hand, differences did occur in the mechanisms of energy delivery during isoproterenol stress: (1) In group A (aortic stenosis without angina or coronary artery disease), coronary flow increased normally, myocardial oxygen extraction decreased, and myocardial lactate production occurred in only one of seven patients. This suggested that energy supply was, generally, adequate to demand. (2) In group B (critical aortic stenosis with angina but no coronary disease), coronary flow rose insignificantly, myocardial oxygen extraction actually increased in three of five patients, and abnormal glycolysis occurred in all patients. This suggested that little or no reserve for increased coronary flow existed and that compensatory mechanisms had to be summoned. (3) In group C (aortic stenosis with angina and coronary artery disease), coronary flow rose normally, myocardial oxygen extraction decreased normally, but abnormal lactate metabolism occurred in most patients. This suggested adequate overall coronary reserve but evidence of regional ischemia.
The Deleterious Role of Tachycardia in Mitral Stenosis
Authors: ARANI DJAVAD T. , CARLETON RICHARD A.
Published: June 2012

Eleven patients with mitral stenosis and atrial fibrillation were studied during artificially induced tachycardia to determine the influence of rapid ventricular rates on hemodynamic variables. Significant elevation of pulmonary artery pressure occurred, but no increase in calculated pulmonary arterial resistance was found. Pulmonary arterial wedge pressures rose in each patient with an average increase of 7 mm Hg. Cardiac output fell at the fastest rate in each patient. These changes from rapid ventricular rates appear to account for the functional deterioration often encountered in patients with mitral stenosis with the advent of atrial fibrillation.
Multiple-Lead Exercise Electrocardiography
Authors: MASON ROBERT E. , LIKAR IVAN , BIERN ROBERT O. , ROSS RICHARD S.
Published: June 2012

A system of multiple-lead exercise electrocardiography has been applied to the study of 107 normal subjects and 67 patients with angina pectoris. The results of this test are compared to those of coronary cinearteriography in 84 patients. In-exercise ECGs gave useful additional information in 59% of the angina patients but were essential for interpretation in 9%. It added considerably to the safety of the test. The value of each individual lead and of the multiple lead system was assessed. Lead V
6
was the most often positive, but each made a contribution in some cases. Test-retest reproducibility survey indicated that five of 65 tests on 25 subjects failed to conform. Evidence has been presented that 1.0 mm of ischemic S-T segment shift was the best criterion for a positive test in the subjects studied. The test was positive in 84% of 67 patients with angina pectoris and 3.7% of 107 normal subjects (excluding vasoregulatory hyperreactors). The double two-step test given to the first 41 of the same angina patients for comparison was found to give 61% positive reactions despite the use of multiple leads and in-exercise recording. The test was administered to 84 subjects who were studied concurrently by selective coronary cinearteriograms and these two parameters were compared with the clinical diagnosis of angina in each patient. Since each of these parameters represents a different facet of coronary arterial disease, the agreement among them is very instructive.
Effects of Propranolol on Patients with Complete Heart Block and Implanted Pacemakers
Authors: DONOSO EPHRAIM , COHN LAWRENCE J. , NEWMAN BERTRAM J. , BLOOM HENRY S. , STEIN WILLIAM C. , FRIEDBERG CHARLES K.
Published: June 2012

The effects of beta-adrenergic blockade with propranolol were studied in 10 patients with complete heart block and fixed rate internal pacemakers. The patients were grouped according to the absence or presence of premature systoles before propranolol was given. In the patients with premature systoles propranolol was uniformly effective in abolishing the premature systoles. Propranolol was found to increase the systemic venous pressure, to decrease the cardiac output, and to lower myocardial contractility both at rest and during exercise in both groups. Since the heart rate was fixed, it was concluded that beta-adrenergic blockade has a significant negative inotropic effect, in addition to the chronotropic effect.
Thoracic Duct-to-Pulmonary Vein Shunt in the Treatment of Experimental Right Heart Failure
Authors: COLE WILLIAM R. , WITTE MARLYS HEARST , KASH STEPHEN L. , RODGER MALCOLM , BLEISCH VIRGIL R. , MUELHEIMS GERHARD H.
Published: June 2012

Elevated venous pressure in right heart failure leads not only to an increase in lymph formation but also to progressive resistance in the neck to the return of lymph to the circulation via the thoracic duct. Sequestration of fluid behind the failing heart tends to protect the circulation but at the same time leads to the clinical manifestations of heart failure.

The present study was performed on 40 dogs with combined tricuspid insufficiency and pulmonary stenosis. Thoracic duct lymph flow was greatly increased. Pressure was considerably greater in the systemic veins than in the pulmonary vein beyond the right heart obstruction. Lymph flow was substantially enhanced when the thoracic duct was connected to the lower pressure pulmonary veins. Furthermore, direct anastomosis of the thoracic duct to the pulmonary vein resulted in fall in systemic venous pressure, increase in renal excretion of salt and water, and reduction in ascites. These results indicate that alterations in the flow of thoracic duct lymph have important bearing on the manifestations and treatment of right heart failure.
Renal Response to Pyrogen in Normotensive and Hypertensive Man
Authors: GOMBOS ERVIN A. , LEE TAE HUNG , SOLINAS JOSEPH , MITROVIC MIRA
Published: June 2012

Pyrogen, when administered intravenously to normotensive and hypertensive men, produced initially vasoconstriction and subsequently marked renal vasodilatation, both resulting from direct effects on the renal vasculature. The absolute renal plasma flow, both during control observations and at the height of renal hyperemia, was greater in normotensives, but the percentage change was greater in hypertensive subjects. Extraction of
p
-aminohippurate diminished during renal hyperemia. Medullary renal plasma flow was higher in normotensive subjects both during control observations and at the height of renal hyperemia. Simultaneously with the development of renal hyperemia, sodium excretion increased without alterations in filtered load of sodium and was prompt in its development in normotensives and delayed in hypertensives. This is attributed to a transient, small, yet probably significant decrease in filtered load of sodium during vasoconstriction immediately following the administration of pyrogen.

Simultaneously with the development of renal hyperemia, there was in both groups an increase in solute excretion and tubular reabsorption of solute-free water.
Prognostic Value of Plasma Renin Activity in Renovascular Hypertension
Authors: MEYER PHILIPPE , ECOIFFIER JEAN , ALEXANDRE JEAN M. , DEVAUX CLAUDINE , GUIZE LOUIS , MENARD JOËL , BIRON PIERRE , MILLIEZ PAUL
Published: June 2012

Renin activity was measured in 248 plasma samples from 78 hypertensive patients with unilateral angiographic renovascular lesions. The humeral (brachial), the two renal, and the suprarenal or the infrarenal caval, or both, veins were sampled. Peripheral vein renin was poorly correlated with surgical success. Venous renin from the involved kidney was better but still failed consistently to predict postoperative benefit. Only in blood from the suprarenal portion of the vena cava were renin levels of considerable prognostic value (87% accuracy) in operated patients. Increases at this level seem to reflect more closely absolute increments in renin secretion rates, whereas increases limited to the venous blood from a stenosed kidney seem to stem mostly from reduced renal blood flow. It is concluded that determination of suprarenal renin deserves a larger scale investigation to define its place among the preoperative tests used for predicting renosurgical benefit in unilateral renovascular hypertension.
Termination of Reciprocating Tachycardia by Atrial Stimulation
Authors: MASSUMI R. A. , KISTIN A. D. , TAWAKKOL A. A.
Published: June 2012

Recurrent tachycardia in a 10-year-old child with acute rheumatic carditis was interpreted as being produced by a reciprocating (circus) mechanism involving either the normal atrioventricular pathway or the anomalous pathway of the Wolff-Parkinson-White syndrome. The tachycardia could be stopped by appropriately timed, electrically induced, atrial premature systoles, which apparently interrupted the circus movement.
Effect of Diphenylhydantoin on Left Ventricular Function in Patients with Heart Disease
Authors: LIEBERSON ALAN D. , SCHUMACHER RICHARD R. , CHILDRESS RICHARD H. , BOYD DANIEL L. , WILLIAMS JOHN F.
Published: June 2012

The effect of 250 mg of diphenylhydantoin, administered intravenously, on left ventricular function was determined during cardiac catheterization in nine patients with heart disease.

Five minutes after drug administration, left ventricular end-diastolic pressure rose in each patient from an average of 6.0 mm Hg to 10.0 mm Hg. Concurrently, stroke work and stroke power indices decreased in each patient by an average of 22.0% and 22.2%, respectively. Stroke volume index decreased in seven patients and maximum left ventricular dp/dt fell in eight patients. Over the next 25 minutes, all parameters returned to control values. Cardiac index was unchanged, whereas generally small and insignificant changes were observed in heart rate and systemic arterial pressure throughout the study.

Although this study has demonstrated that diphenylhydantoin depresses myocardial function, the effect may have limited clinical significance since it was relatively short-lived and did not reduce cardiac output or greatly elevate ventricular end-diastolic pressure. Furthermore, the absence of a significant systemic hypotensive effect is of distinct clinical importance.
Tall Upright T Waves in the Precordial Leads
Authors: PINTO IVAN J. , NANDA N. C. , BISWAS A. K. , PARULKAR V. G.
Published: June 2012

One hundred ten cases of T waves more than 10 mm in height in the precordial leads were studied. The T waves were wide in ischemic heart disease and thin and peaked in uremia. Marked changes in the ventricular gradient were observed in ischemic heart disease and in uremia with hyperkalemia. In other conditions, the changes in the ventricular gradient were of a lesser degree. In cases of left ventricular hypertrophy, the T waves were tall from V
1
to V
4
in systolic (pressure) overloading, from V
4
to V
6
in diastolic (volume) overloading, and from V
2
to V
6
in combined types of overloading.

The appearance of tall T waves was the earliest electrocardiographic sign encountered in clinical and experimental cases of acute myocardial infarction. In anterior myocardial infarction they disappeared within 24 hours indicating initial transient ischemia, while in angina pectoris and posterior myocardial infarction they lasted for a longer time probably due to persistent subendocardial ischemia.
The Percutaneous Femoral Artery Approach to Selective Coronary Arteriography
Authors: SPELLBERG RICHARD D. , UNGAR IRVIN
Published: June 2012

Experience in performing 267 selective coronary arteriograms by both the exposed brachial artery and percutaneous femoral artery techniques has proved the latter to be the technique of choice.

The percutaneous femoral artery approach obviates the need for performing a cutdown over the small caliber brachial artery with the associated difficulties of catheter manipulation from this vessel. We have been able to intubate the left coronary artery with ease in all of 122 patients in whom this approach was attempted. The right coronary has been selectively entered in approximately 90% of these patients. The stability of the position of the catheter in the coronary ostia during manipulation of the patient, coughing, and deep breathing is an outstanding feature of this technique.
The Hemodynamic Response to Exercise in Patients With Healed Myocardial Infarction Without Angina
Authors: PARKER JOHN O. , WEST ROXROY O. , DI GIORGI SALVATORE
Published: June 2012

Fifteen patients with coronary heart disease and previous myocardial infarction but without exertional angina were studied at rest and during exercise. The hemodynamic response to exercise varied, being normal in some patients while others showed evidence of marked depression of ventricular performance. Ten patients were restudied after nitroglycerin. During exercise after administration of this drug, ventricular performance was normal in all. The exact mechanism of action of nitroglycerin is uncertain, but it may reduce myocardial oxygen needs through reduction in left ventricular volume or increase in coronary blood flow to ischemic areas or both.