bluuebunny/crossref_metadata_2025 huggingface dataset:
Severe Pulmonic Stenosis with Intact Ventricular Septum and Right Aortic Arch
Authors: GAMBLE WALTER J. , NADAS ALEXANDER S.
Published: June 2012

Three cases with pulmonary stenosis, intact ventricular septum, and right aortic arch are presented, along with physiologic data. Two cases had infundibular stenosis and, in addition, an aberrant left subclavian artery. The third case was thought to have valvular stenosis. All three patients have been successfully operated upon and show good clinical results.
Digitalis Intoxication Following Conversion to Sinus Rhythm
Authors: GILBERT ROBERT , CUDDY RICHARD P.
Published: June 2012

The records of 28 patients receiving digitalis and converted from atrial fibrillation or flutter to sinus rhythm with direct-current countershock were reviewed. Electrocardiographic signs suggesting digitalis intoxication following conversion occurred in 20 of these cases. Two of these patients died as a result of ventricular fibrillation several hours after apparently successful conversion. Six patients on digitalis treated with countershock but not converting and five patients converted with countershock who were not receiving digitalis or in whom digitalis had been discontinued for several days failed to show these electrocardiographic abnormalities. The results indicate that digitalis intoxication will often appear following conversion to sinus rhythm when no indication of digitalis intoxication was present prior to conversion. It is recommended that digitalis be withheld for several days in subjects for whom a conversion attempt is planned.
The Straight Back Syndrome
Authors: DE LEON ANTONIO C. , PERLOFF JOSEPH K. , TWIGG HOMER , MAJD MASSOUD
Published: June 2012

Analysis of the cardiovascular manifestations caused by loss of thoracic kyphosis has been incomplete. Accordingly, this study was designed to investigate the physical signs and the electrocardiographic, radiologic, hemodynamic, and pulmonary ventilatory features of this skeletal defect. Twenty-three patients with straight thoracic spines in lateral chest x-rays were selected. Ratios of anteroposterior to transthoracic dimensions were uniformly below a mean derived from 100 normal subjects. Cardiac features included pulmonic ejection murmurs, palpable left parasternal systolic impulses, loud delayed sounds of tricuspid valve closure, exaggerated respiratory splitting of the second heart sound, vertical electrical axes, rSr' patterns in leads V
1
or aV
R
, radiologic prominence of the pulmonary arteries, levodisplacement of the heart, a "pancake" cardiac configuration simulating cardiomegaly, occasional alterations in height or contour of the right ventricular diastolic pressure pulse, and an occasional mild pulmonary ventilatory restrictive defect. Differential diagnoses principally included atrial septal defect, mild pulmonic stenosis, and idiopathic dilatation of the pulmonary artery.
Acute Effects of Countershock Conversion of Atrial Fibrillation upon Right and Left Heart Hemodynamics
Authors: REALE ATTILIO
Published: June 2012

Right and left heart hemodynamics were studied in 12 patients with mitral valvular disease and atrial fibrillation before and immediately after external direct-current countershock resulting in restoration of normal sinus rhythm. The change of rhythm was accompanied by the following hemodynamic variations in the majority of cases: Systolic and mean pressures in the right and left ventricles and in the pulmonary and brachial arteries were not systematically altered, with a tendency, however, to a decrease in ejection pressures in the right heart and increase in the left heart. Mean right atrial and right ventricular end-diastolic pressures as well as left ventricular end-diastolic pressure decreased significantly. The behavior of the mean left atrial pressure appeared to be influenced by the degree of mitral valvular disease. Cardiac output and index and stroke volume and index increased; pulmonary vascular and systemic resistances decreased.

The stroke work of the ventricles also increased in the majority of patients.

An analysis of the changes in left ventricular end-diastolic pressure in relation to the left ventricular stroke work indicated that sinus rhythm resulted usually in a shift of the ventricular function curve to an area of improved performance.
Precordial Movements over the Right Ventricle in Children with Pulmonary Stenosis
Authors: SCHMIDT ROLAND E. , CRAIGE ERNEST
Published: June 2012

Twenty-three children with pulmonary stenosis were studied by means of displacement tracings taken over the right ventricle. The transducer was selected to pick up vibrations in the ultra-low frequency or palpable range. The patients were studied by cardiac catheterization and angiocardiography.

Criteria previously established for normal children were applied to the patients with pulmonary stenosis. These provide a measure of the duration and relative height of the out-ward movement associated with ventricular systole.

Recordings of precordial movement over the right ventricle in all of five children with severe pulmonary stenosis were abnormal by these criteria. Patients with mild pulmonary stenosis were normal in six of seven cases. An intermediate group (right ventricular peak pressures 60 to 100 mm. Hg) had abnormal records in seven of 11 instances. The "a" wave resulting from atrial contraction was exaggerated in severe pulmonary stenosis and was larger than normal in many of the mild and moderate cases.

Recordings of precordial movement in pulmonary stenosis, though nonspecific in morphology, are nevertheless useful as an index of severity of the lesion, in timing phases of the cardiac cycle, in following the progress of cases before and after surgical interference, and as a method of improving appreciation of palpable phenomena at the bedside.
Late Hemodynamic Response to Correction of Isolated Pulmonary Stenosis by Open Operation during Pulmonary Bypass
Authors: LILLEHEI C. WALTON , SIMMONS ROBERT L. , TODD DAVID B.
Published: June 2012

A group of 25 patients was studied by cardiac catheterization before and after open operation for isolated pulmonary stenosis by direct vision with use of cardiopulmonary bypass Organic infundibular obstruction, when present, was resected. The hypertrophied infundibulum, when it constitutes a severe obstruction, must also be resected. The average right ventricular systolic pressure preopratively was 124 mm. Hg and postoperatively it was 35 mm. Hg.

The average gradient across the pulmonary valve preoperatively was 99 mm. Hg and postoperatively it was 17 mm. Hg, a mean decrease of 82 mm. Hg.

The long-term hemodynamic response was distinctly superior in this group of patients operated upon under total bypass when compared with a similar series operated upon by us with a closed transventricular approach.

The specific diagnosis of lesions causing obstruction to the outflow of the right ventricle is particularly crucial in selecting an operative approach if open operation by inflow stasis is utilized.

Careful review of the selective right ventriculograms is an excellent preoperative guide in determining whether infundibular obstruction is present and hemodynamically significant.

Patients having severe valvular stenosis, with right ventricular pressures above 140 to 150 mm. Hg should have an immediate one-third to one-half decrease in their right ventricular systolic pressures at the time of surgery, or infundibular resection should be done to reduce postoperative mortality.
Mumps of the Heart
Authors: ROBERTS WILLIAM C. , FOX SAMUEL M.
Published: June 2012

The clinical and pathologic findings of a patient who died from diffuse myocardial disease 8 months after an attack of mumps is presented. His illness was complicated by myocarditis, meningoencephalitis, pancreatitis, and orchitis. A study of past reports discloses that electrocardiographic evidence of myocardial involvement in mumps is common, that clinical evidence of myocardial involvement is unusual, and that death from myocardial involvement is extremely rare.
Significance of the QX/QT Ratio and the QT Ratio (QTr) in the Exercise Electrocardiogram
Authors: ROMAN LAURIAN , BELLET SAMUEL
Published: June 2012

Recently, a junctional depression of small amplitude (less than 2 mm.) of the ST segment was considered to be a positive or equivocal result for the electrocardiographic exercise test if the QX/QT ratio was ⪖ 50 per cent or the QTr ⪖ 1.08.

In 150 normal, young students with no clinical evidence of heart disease, a junctional depression of the ST segment with a QX/QT ratio ⪖ 50 per cent or a QTr ⪖ 1.08 or both, was observed in 22 per cent.

These observations, supported by other published reports concerning the QX/QT ratio and the QTr, indicate that these criteria are not reliable for the determination of a positive electrocardiographic exercise test.
Fibroma of the Right Ventricle Producing Severe Tricuspid Stenosis
Authors: VAN DER HAUWAERT LUKE G. , CORBEEL LUCIEN , MALDAGUE PAUL
Published: June 2012

A case of fibroma of the right ventricle in a child of 16 months is reported. The clinical and hemodynamic findings were those of severe tricuspid stenosis. Angiocardiography proved the obstruction to be due to a cardiac neoplasm, localized within the right ventricle. An attempt at surgical removal failed because the tumor, almost completely filling the cavity of the right ventricle, was too extensive and could not be distinctly delineated from the healthy myocardium.
The Role of Hydrogen Ion Concentration in the Regulation of Pulmonary Arterial Pressure
Authors: VOGEL JOHN H. K. , BLOUNT S. GILBERT
Published: June 2012

The relative importance of arterial oxygen tension and hydrogen ion concentration in regulating pulmonary arterial pressure was evaluated in a 43-year-old woman with hypoventilation and obesity. It was shown that hydrogen ion concentration played a dominant role in the regulation of her pulmonary circulation.
Fatal Cerebral Embolism Complicating Transseptal Left Heart Catheterization
Authors: KOSSOWSKY WARREN A. , BLEIFER SELVYN B.
Published: June 2012

A case of fatal cerebral embolism complicating transseptal left heart catheterization is presented. Some of the previously reported complications of this procedure are reviewed. Fatal cerebral embolism must now be added to the list of potential hazards of this procedure.
Influence of a Diet High in Unsaturated Fat upon Composition of Arterial Tissue and Atheromata in Man
Authors: DAYTON SEYMOUR , HASHIMOTO SAM , PEARCE MORTON LEE
Published: June 2012

Detailed chemical analyses have been carried out on aorta, and on coronary and aortic atheromata, of men who died during a study of prolonged use of diets rich in unsaturated fat and of control subjects. Concentrations of total aortic lipid and of total aortic calcium were not significantly different for the two groups of subjects. Concentrations of cholesterol and cholesterol esters, triglyceride, and phosphatide showed no difference between the two groups in analyses of aorta, uncomplicated aortic atheromata, complicated aortic atheromata, and coronary atheromata. Coronary atheroma lipid contained substantially more triglyceride than did aortic atheroma lipid, whether derived from complicated or uncomplicated plaques.

Atheroma triglyceride in experimental subjects contained more linoleic acid than in control subjects, in all types of plaques. Lesser but significant increases in linoleic acid were seen in cholesterol ester and phosphatide of coronary atheromata and complicated aortic atheromata. In the case of uncomplicated aortic atheroma, changes in linoleic acid of cholesterol ester and phosphatide were smaller and not significant. In both groups of subjects, coronary atheroma contained more cholesteryl oleate and less linoleate than did aortic atheroma.

Linoleic acid contents of atheroma lipid fractions were positively correlated with the linoleic acid figures for corresponding fractions of the most recent antemortem serum samples. Ratio of linoleic acid in an atheroma lipid fraction to the linoleic acid content of the corresponding serum fraction was, in most cases, constant after the time of the first sample, obtained after 495 days on experimental diet. It is postulated that this ratio constitutes an estimate of the fraction of atheroma fatty acid derived from plasma. In cholesterol ester and triglyceride, the ratio was about 0.65 in experimental subjects, higher in subjects on the control diet. The ratio for phosphatide was about 0.5 in both groups of subjects.
The Effect of Nitroglycerin on the Systemic and Coronary Circulation in Man and Dogs
Authors: BERNSTEIN L. , FRIESINGER G. C. , LICHTLEN P. R. , ROSS R. S.
Published: June 2012

The pharmacodynamics of nitroglycerin have been studied in dogs and man.

In dogs, intravenous nitroglycerin (TNG) caused a decrease in left ventricular work, myocardial blood flow (MFB), and myocardial oxygen consumption, and no significant change in coronary vascular resistance.

Intracoronary artery TNG in dogs caused an immediate increase in MBF and a decrease in coronary vascular resistance that persisted until arterial pressure fell.

In man, sublingual TNG (0.4 mg.) caused a decrease in left ventricular work, MBF, and myocardial oxygen consumption, and no significant decrease in coronary vascular resistance in patients with and without arteriographically proven coronary artery disease.

The injection of doses of 0.1 to 0.2 mg. of TNG directly into the coronary artery in man caused an immediate increase in MBF and a decrease in coronary vascular resistance in patients with and without arteriographically proven coronary artery disease.

The hypothesis proposed for the mechanism of action of TNG in the relief of angina pectoris is first, a decrease in coronary vascular resistance due to its effect on the coronary circulation, and, secondly, a decrease in cardiac work due to its effect on the systemic circulation.
Perforation during Indwelling Catheter Pacing
Authors: NATHAN DAVID A. , CENTER SOL , PINA RAUL E. , MEDOW AARON , KELLER WALTER
Published: June 2012

Nine patients paced with an indwelling catheter as a preoperative measure prior to synchronous pacer implantation were observed at surgery to have catheter perforation into the pericardium within 1 to 14 days. Such perforation may result from mechanical systole when the catheter tip becomes fixed in the trabeculae carneae of the right ventricular outflow tract and is progressively forced through the thin myocardial wall. Stimulation may be uninterrupted, intermittent, or absent in the presence of catheter perforation. Since hemopericardium has been observed without symptoms or radiologic evidence, the physician should be aware of this possible complication and its potentially serious effect.
Pre-Excitation as a Cause of Appearance and Increased Intensity of Systolic Murmurs
Authors: BERGLAND JOHN M. , RUCKER WARREN R. , REEVES JOHN T. , SURAWICZ BORYS
Published: June 2012

In three patients with a Wolff, Parkinson, White (WPW) pattern and systolic murmur, the murmur disappeared or decreased in intensity when the WPW pattern disappeared or became less pronounced. The accentuation of the murmur of tricuspid and mitral insufficiency suggests that pre-excitation may be responsible for an increase in regurgitant flow in patients with these lesions. A "functional" murmur may appear only during pre-excitation. The appearance or increased intensity of the murmur is presumably related to the altered patterns of ventricular activation and contraction accompanying the WPW pattern.
Norepinephrine Stores and Contractile Force of Papillary Muscle from the Failing Human Heart
Authors: CHIDSEY CHARLES A. , SONNENBLICK EDMUND H. , MORROW ANDREW G. , BRAUNWALD EUGENE
Published: June 2012

The relation between cardiac norepinephrine concentration and the functional state of the myocardium was studied in left ventricular papillary muscles removed from patients with congestive heart failure at the time of mitral valve replacement. Myocardial function was assessed by determining the maximum isometric active tension that the papillary muscle could develop in an in vitro system, and by measuring the increase in active tension in response to the norepinephrine-releasing sympathomimetic amine, tyramine. The norepinephrine concentration averaged 0.36 µg./Gm. in 17 muscles. In eight of these a response to tyramine was observed with a 21-per cent increase in active tension, and the norepinephrine concentrations averaged 0.53 µg./Gm.; in the other six muscles tested with tyramine no positive inotropic response was observed, and the norepinephrine concentration was significantly lower, averaging 0.16 µg./Gm. The maximum active tension in 17 muscles averaged 1.78 Gm./mm.
2
, and a significant positive correlation between the maximum tension and the norepinephrine concentration of the individual muscles was observed. In the eight muscles responding to tyramine, the maximum tension observed, 2.34 Gm./mm.
2
, was significantly greater than that observed in the six muscles unresponsive to tyramine, 0.64 Gm./mm.
2
It is concluded that norepinephrine depletion appears to be associated with defective myocardial function although no causal relationship between these two abnormalities has been established.
Hemodynamic Changes Associated with Injection of Angiocardiographic Contrast Medium in Assessment of Valvular Lesions
Authors: RAHIMTOOLA SHAHBUDIN H. , DUFFY JOHN P. , SWAN H. J. C.
Published: June 2012

Measurements of flow and pressures related to the left heart were made on 21 patients immediately prior to and at intervals of 2 and 4 minutes after angiocardiography. These patients had normal mitral valves (group 1), mitral incompetence (group 2), or mitral stenosis (group 3). There was an increase in left ventricular end-diastolic pressure accompanied by an increase in "pulmonary artery wedge" (PA wedge) pressure in all patients. Patients with mitral valve disease generally develop higher PA wedge pressures; those with mitral stenosis develop, in addition, significantly increased mean diastolic and end-diastolic gradients across the mitral valve.

These increased gradients in mitral stenosis are due to increased flow across the mitral valve, which results from a combination of increased cardiac output and decreased diastolic filling time. Diagnostic angiocardiography affords an opportunity of observing the effects of valve lesions at a higher flow rate and is particularly useful in those patients with normal PA wedge pressure and small gradients initially.
Percutaneous Suprasternal Puncture (Radner Technique) of the Pulmonary Artery in Transposition of the Great Vessels
Authors: RAHIMTOOLA SHAHBUDIN H. , ONGLEY PATRICK A. , SWAN H. J. C.
Published: June 2012

Introduction of a cardiac catheter into the pulmonary artery from the right heart is not possible in a substantial proportion of patients with transposition of the great vessels. It is necessary to obtain the pulmonary artery pressure and oxygen saturation value to evaluate the degree of pulmonary stenosis and the pulmonary vascular resistance. Twenty-three patients are described in whom this was accomplished by percutaneous suprasternal puncture. There was no mortality and there were no significant complications. The technique appears to be safe and reliable.
The Assessment of Operative Results in Congenital Heart Disease by Intraoperative Indicator-Dilution Curves
Authors: MORROW ANDREW G. , OLDHAM H. NEWLAND , CALLARD GEORGE M. , BRAUNWALD EUGENE
Published: June 2012

In 260 patients with intracardiac shunts, indicator-dilution curves were recorded immediately after corrective operations. In every patient, the effectiveness of the repair was also determined at late postoperative cardiac catheterization or necropsy. In 248 patients (96 per cent) the presence or absence of a shunt, determined from the intraoperative curves, was confirmed by the findings at postoperative study. The intraoperative curves were normal in 213 patients, 209 of whom had no residual communication at late evaluation; in four patients, the studies indicated initial complete correction followed by recurrence of the shunt. Abnormal intraoperative curves were recorded in 47 patients, eight of whom died. In 17 of the 39 surviving patients, postoperative catheterization revealed persistent residual shunts comparable in magnitude to those present before operation. Fourteen patients had residual shunts that did not necessitate reoperation, and in eight patients, shunts present at the conclusion of the operation were shown to close in the postoperative period.

The study indicates that the recording of intraoperative indicator-dilution curves provides a reliable objective method for evaluating the effectiveness of operation in patients with circulatory shunts. If normal curves are recorded, no residual shunt may be expected in 98 per cent of patients, and postoperative catheterization may be unnecessary unless other hemodynamic data are required. If abnormal intraoperative curves are recorded, however, postoperative study is mandatory, since the shunt will persist in 80 per cent of patients, in many of whom a second operation will be indicated.
Plasma Cephalins of Patients with Acute Myocardial Infarction
Authors: NOTHMAN MARTIN M. , PROGER SAMUEL
Published: June 2012

In the plasma of patients with acute myocardial infarction the values for phosphatidyl ethanolamine are on the average 50% to 100% higher than in patients with chronic coronary heart disease and up to 400% higher than in normal individuals. Those for phosphatidyl serine are about 50% higher than in patients with chronic coronary heart disease and up to 300% higher than in normal individuals. Expressed in percentages of total phospholipids, the share of phosphatidyl ethanolamine in acute myocardial infarction is about twice as high as in chronic coronary heart disease and three times as high as in healthy persons. The share of phosphatidyl serine is about 50% higher than in patients with chronic coronary heart disease and also almost 300% higher than in healthy persons. Following the acute incident the values for the cephalins, both phosphatidyl ethanolamine and phosphatidyl serine, decrease slowly. Phosphatidyl ethanolamine reaches the level found in patients with chronic coronary heart disease in about 4 weeks, phosphatidyl serine in about 1 week.
Studies of the Retinal Circulation in Man
Authors: HICKAM JOHN B. , FRAYSER REGINA
Published: June 2012

By photographic techniques measurements have been made in the human retina of vessel size, arteriovenous oxygen difference across the retina, and mean retinal circulation time. By combination of these methods estimates can be made of relative changes in retinal blood flow rate and in the rate of oxygen delivery from the retinal vascular system. Observations are presented on the response of the normal and diseased retinal circulation to a variety of stimuli, particularly changes in blood oxygen and carbon dioxide tensions.
Observations on the Assessment of Cardiac Hypertrophy Utilizing a Chamber Partition Technique
Authors: BOVE KEVIN E. , ROWLANDS DAVID T. , SCOTT RALPH C.
Published: June 2012

Three hundred fifty-four adult human hearts were dissected utilizing a technique similar to those previously described by Müller
1
and Lewis.
2
A classification was synthesized on the basis of anatomic characteristics of 100 normal hearts. Presumptive evidence of either left or right ventricular overload, provided by clinical and autopsy observation, served as essential corollary data in establishing normal limits. The existence of hypertrophy was readily recognized in hearts in which one or both ventricles increased in mass sufficiently to surpass the defined upper limit. Isolated ventricular hypertrophy of mild degree was recognized as a consequence of an abnormal LV+S/RV ratio in 58 hearts in which ventricular weights were within the normal range. Factors which would be expected to result in left or right ventricular overload were demonstrable in 42 of these cases. Atrial hypertrophy correlated well with hypertrophy of the corresponding ventricle and served as an invaluable aid in recognition of mild degrees of combined ventricular hypertrophy. This classification constitutes the basis for a subsequent correlative electrocardiographic study.
The Vectorcardiogram of Left Ventricular Hypertrophy
Authors: VARRIALE PHILIP , ALFENRRO JOSEPH C. , KENNEDY RICHARD J.
Published: June 2012

Direct spatial vectorcardiograms were made by using the Frank lead system on 50 patients with known left ventricular hypertrophy of both systolic and diastolic overload types. Three distinctive loop patterns were demonstrated in the horizontal plane. In addition important quantitative measurements are described for the three planar projections. From these data, five criteria are proposed for the definitive vectorcardiographic diagnosis of left ventricular hypertrophy.
Anomalous Origin of the Left Coronary Artery from the Pulmonary Artery
Authors: CASTAÑEDA ALDO R. , INDEGLIA ROBERT A. , VARCO RICHARD L.
Published: June 2012

Nine cases of anomalous origin of the left coronary artery from the pulmonary artery, the patients ranging in age from two months to seven years, have been reviewed. Six of these patients have had mitral insufficiency as well.

Of these nine patients, four have undergone operation and all have survived. There have been no postoperative complications. A fifth patient was taken to the operating room, but developed ventricular fibrillation during induction and could not be resuscitated. The remaining patients were not operated upon, and all have died.

In a typical case, nonspecific respiratory complaints were present. In addition, some patients experienced episodes of pallor, dyspnea, and excessive perspiration. The electrocardiogram and vectorcardiogram proved helpful in the diagnosis of this anomaly, although selective right coronary arteriography was most effective in establishing the diagnosis.

The surgical treatment in all four patients consisted of transection and ligation of the anomalous coronary artery at its origin from the pulmonary artery. The technique is simple and has been described. Of the four surgically treated patients, three have so far remained asymptomatic. One patient continues postoperatively to suffer from angina-like symptoms. The electrocardiogram, vectorcardiogram, and chest X-rays do not show any marked change from preoperative observations in three patients; however, the youngest child operated upon (aged three months) reveals changes consistent with improvement in the electrocardiographic pattern.

Early recognition and treatment of this lesion are advocated if preventable deaths from irreversible myocardial damage are to be avoided.
Simultaneous Red Cell and Plasma Protein Indicator-Dilution Curves Across the Peripheral Circulation During Open-Heart Surgery
Authors: GIANNELLI STANLEY , AYRES STEPHEN M. , WOLFF WILLIAM I. , BUEHLER META , CONKLIN E. FOSTER
Published: June 2012

Data have been presented showing the applicability of indicator-dilution technique to the entire human peripheral circulation during open-heart surgery. Initial results from simultaneous tagged red cell and plasma protein indicator-dilution curves demonstrate a consistently greater volume of distribution for plasma proteins than for red cells.
A Study of Coronary Heart Disease in Young Men
Authors: HATCH FREDERICK T. , REISSELL PENTTI K. , POON-KING THEO. M. W. , CANELLOS GEORGE P. , LEES ROBERT S. , HAGOPIAN LILLIAN M.
Published: June 2012

To study metabolic factors in the genesis of coronary heart disease in previously healthy young adults, 24 men (aged 23 to 49 years) who had recovered from proven myocardial infarction were compared with an age-matched series of 20 healthy subjects-10 business and professional men and 10 prisoners. Both series averaged 10% above ideal body weight. The patients were shorter, were heavier smokers, and had a high familial incidence (70%) of coronary heart disease. The controls had more familial diabetes.

Oral glucose tolerance tests without and with cortisone showed higher peak blood sugar levels and delayed return in the patients. Four patients were found to have fasting serum triglycerides above 300 mg% and were placed in a separate category of essential hyperlipidemia. In the remaining 20 patients, serum cholesterol and triglycerides in combination were higher than in the controls, together with elevation of pre-β-lipoproteins. α
1
-Lipoprotein was decreased. Mean postheparin lipolytic activity was slightly less in the patients-in the lower part of the normal range.

In the combined series of patients and control subjects, the relative body weight showed significant correlations-directly with the 1-hour blood sugar level in the glucose tolerance test and with the fasting serum triglyceride level, and inversely with the α
1
-lipoprotein. The relative body weight did not show a significant correlation with the serum cholesterol level.

A set of 10 characteristics and biochemical variables, referred to in preceding paragraphs, was found to discriminate well between the patients and their controls. The total incidence of abnormal findings was high among the patients (mean, 4.9 per man) and low among the controls (mean, 1.9 per man), but the positive items were grouped in many different ways in individuals.

Analysis of the data suggests that over-nutrition and heavy smoking interact with hereditary factors in certain individuals to accelerate the progress of coronary atherosclerosis. Since individuals who exhibit many of the criteria indicative of increased risk are not uncommon in our population, their identification as candidates for coronary heart disease early in life is a significant public health problem.
Depletion of Body Potassium by Diuretics
Authors: REMENCHIK ALEXANDER P. , MILLER CHARLES , TALSO PETER J. , WILLOUGHBY EDWARD O.
Published: June 2012

A study was designed to evaluate the [see table in the PDF file] [see table in the PDF file] hypothesis that the hypokalemia associated with the administration of thiazide diuretics reflects a redistribution of potassium rather than a depletion of body potassium. Exchangeable potassium, total body potassium, total body water, extracellular fluid volume, and serum sodium, potassium, chloride, bicarbonate, and pH of a group of hypertensive subjects were measured before and after 4 weeks of administration of dichlorphenamide and hydrochlorothiazide to these subjects.

Significant decreases were observed in serum potassium (1.05 mEq/L), serum chloride (8.22 mEq/L), exchangeable potassium (21.1%), and total body potassium (16.7%) without a significant change in serum pH, sodium, and bicarbonate. Body weight, total body water, and extracellular fluid volume also decreased, but the change in body weight was not sufficient to explain the potassium deficit produced. The mechanisms responsible for the loss of potassium are discussed.
Cerebral Hemodynamics, Blood Gases, and Electrolytes during Breath-Holding and the Valsalva Maneuver
Authors: MEYER JOHN S. , GOTOH FUMIO , TAKAGI YASUYUKI , KAKIMI RYOJI
Published: June 2012

Continuous recordings of arterial and internal jugular blood oxygen tension, oxygen saturation, carbon dioxide tension, pH, sodium and potassium, together with PECO
2
, blood pressure, and electroencephalogram were obtained to compare the effects of inspiratory and expiratory breath-holding and the Valsalva maneuver on the cerebral circulation and cerebral oxygen availability in man.

During the interval of tolerated breath-holding for 69 seconds or less, jugular venous oxygen tension was increased owing to increased cerebral blood flow resulting from an increase of arterial carbon dioxide tension. There was a statistically significant correlation between changes in JPO
2
and PaCO
2
, which proved to be more or less linear for both increases and decreases of PaCO
2
4 mm. above and below control levels. No threshold was found for changes in PaCO
2
altering effective cerebral perfusion and cerebral venous PO
2
, extremely small changes in PaCO
2
(less than 1 mm. Hg) altered cerebral oxygen availability within 10 to 20 seconds.

During the Valsalva maneuver a consistent reduction of jugular oxygen tension was found associated with the sudden fall in arterial blood pressure and reduction of arterial carbon dioxide tension. The rapid changes in cerebral hemodynamics and cerebral oxygen availability during the procedure are briefly discussed.
Familial Aggregation of Factors Associated with Coronary Heart Disease
Authors: DEUTSCHER SIGISMOND , EPSTEIN FREDERICK H. , KJELSBERG MARCUS O.
Published: June 2012

In the course of an epidemiological study covering an entire community, Tecumseh, Michigan, the familial aggregation of various levels of four variables associated with coronary heart disease-serum cholesterol, systolic blood pressure, relative weight, and blood glucose after a standard load-was assessed quantitatively by determining the relative frequencies of high, intermediate, and low levels of the variables for several familial combinations. High, intermediate, and low levels for each variable were defined in terms of quintiles (highest, middle three, lowest, respectively) of the distribution of the variable specific for age and sex.

Parents and their children and siblings were compared. There was a striking resemblance between children and their fathers and mothers for all the four variables under study, as well as for height which was used as a frame of reference. The degree of resemblance between parents and children was approximately the same at the three levels-"low," "intermediate," and "high"-of the variables, pointing to a multifactorial mode of determination.

In an attempt to assess the relative role of environmental and genetic factors with respect to the determination of the variables under study, degrees of aggregation by age were compared. An appreciable degree of resemblance was found among siblings below the age of 16 who may be presumed to share the same environment to a great extent. Aggregation was less marked for siblings between the ages of 16 and 40, a time when less of the same environment is shared, but it rose again after age 40. It is postulated that the observed rise after age 40 is due to an increase in the penetrance of the genes involved, at middle age and beyond. In addition, this pattern of aggregation suggests that environmental factors may play a stronger role prior to middle age. A similar subdivision by age, was used to study relationships between parents and children; although no corresponding differences between age groups were found, this apparent inconsistency with the sibship data could be explained, in part, by differences in age composition of the groups involved.

The practical implication of the foregoing pattern of familial aggregation lies in the possibility of specifying for an individual the risk of developing high values of a variable predisposing to coronary heart disease in the future on the basis of the values shown by his parents and siblings.
The Relation of Heart Rate to Cardiovascular Dynamics
Authors: STEIN EMANUEL , DAMATO ANTHONY N. , KOSOWSKY BERNARD D. , LAU SUN HING , LISTER JOHN W.
Published: June 2012

Hemodynamic studies were carried out as heart rates were controlled by atrial pacing on 10 normal patients at rest and during exercise. Each patient served as his own control. In both states tested the cardiac index, left ventricular work, and peripheral resistance were not significantly altered by changes in heart rate. The stroke index and mean systolic ejection rate decreased linearly with heart rate. During exercise the cardiac index increased up to 98% and again remained constant at all paced heart rates tested. At comparable heart rates the tension-time index, left ventricular work, stroke index, and mean systolic ejection rate were higher during exercise than at rest. At comparable heart rates [see figure in the PDF file] peripheral resistance was 38% lower during exercise than at rest. Myocardial oxygen consumption, as inferred from the tension-time index, increased with heart rate in both states.
Effects of Heart Rate on the Dynamics of Force Development in the Intact Human Ventricle
Authors: SONNENBLICK EDMUND H. , MORROW ANDREW G. , WILLIAMS JOHN F.
Published: June 2012

The effects of heart rate on the dynamics of force development in the ventricle were studied in the intact human heart. In the course of corrective cardiac operations, Walton-Brodie strain-gauge arches were sutured to the right ventricles of 11 patients. The peak contractile force, the time to peak force, and the maximum rate of change of force (df/dt) were determined at various heart rates, produced by electrical stimulation of the right atrium or right ventricle. As the rate was increased, from an average of 72 to 145 per minute, no significant change in peak contractile force was observed. The peak df/dt, however, increased with each increment in heart rate, and the time to peak force decreased. This inverse relationship between peak df/dt and time to peak force accounts for the constancy of the peak force observed within several contractions after heart rate was changed. Also, since df/dt and the time to peak force reflect the intensity and duration of the active state, respectively, an inverse relationship between these factors is implied. Sudden changes in heart rate were associated with transient changes in peak contractile force, attributable to differences in the rates with which peak df/dt and time to peak force reached new constant values.

In man, therefore, a "velocity staircase," rather than a "force staircase," occurs with changes in heart rate. The possession of this mechanism apparently permits the human ventricle to maintain its force of contraction and preserve the duration of diastolic filling with increases in rate.
The Hemodynamics of Common (or Single) Ventricle
Authors: RAHIMTOOLA SHAHBUDIN H. , ONGLEY PATRICK A. , SWAN H. J. C.
Published: June 2012

Data from 43 patients with common ventricle for whom satisfactory hemodynamic data are available are presented; these form 3.2% of the patients with congenital heart disease studied by means of catheterization at the Mayo Clinic. Selective biplane angiocardiography is essential for diagnosis of common ventricle. Associated cardiovascular anomalies are common, with transposition of the great vessels occurring in 84% of the patients.

The right-to-left shunt present in all 43 patients results in desaturation of systemic arterial blood. The common ventricle receives all the systemic and pulmonary venous blood [see table in the PDF file] flows; yet complete mixing is uncommon in this chamber, for it occurred in only 16% of the patients who did not have severe pulmonary stenosis. Fifty-eight per cent had oxygenated blood directed preferentially to the systemic circuit ("favorable streaming"). This occurred most commonly with L-transposition and resulted in a higher oxygen saturation of systemic arterial blood. Obstruction to pulmonary flow (from pulmonary stenosis or pulmonary vascular disease) results in a larger right-to-left shunt and lower oxygen saturation of systemic arterial blood.
Anatomic Evidence for Spontaneous Closure of Ventricular Septal Defect
Authors: SIMMONS ROBERT L. , MOLLER JAMES H. , EDWARDS JESSE E.
Published: June 2012

Pathological evidence for spontaneous closure of ventricular septal defect in seven adults has been presented. These cases were observed among 1,605 necropsies (an incidence of about 1 per 225 necropsies).

In two of the cases, the ventricular septal defect was closed by an adherent tricuspid valve, possibly the result of bacterial endocarditis.

In the remaining five cases a muscular ventricular septal defect was closed by a fibrous membrane.
The Gradient in Pressure Across the Pulmonary Vascular Bed During Diastole
Authors: KALTMAN ALFRED J. , HERBERT WALTER H. , CONROY RICHARD J. , KOSSMANN CHARLES E.
Published: June 2012

By means of right and left heart catheterization 70 patients with congenital or acquired heart disease were examined to determine whether or not a gradient in pressure existed between the pulmonary artery and the left ventricle at the end of diastole. In the absence of mitral valvular obstruction in 56 patients there was a statistically significant correlation of pulmonary artery diastolic, left ventricular end-diastolic, and left atrial mean pressures less than 15 mm Hg which was independent of heart rate. Diastolic pressures at identical levels as high as 40 mm Hg were demonstrated in the presence of aortic insufficiency without left ventricular failure, and as high as 47 mm Hg during pulmonary edema in one patient with aortic stenosis and insufficiency. A diastolic gradient in pressure between the pulmonary artery and the left ventricle existed in 14 patients with pulmonary hypertension. These patients all had congenital intracardiac shunts and it may be assumed that they had some obstruction in the pulmonary vascular bed.

These findings suggest that within defined limits friction across the pulmonary vascular bed is so small that a state of pressure equilibrium exists at the end of diastole. When the limits are met clinically, the pressures in the pulmonary artery and in the left ventricle at the end of diastole are identical.
Effect of 9-α-Fluorohydrocortisone on Forearm Vascular Responses to Norepinephrine
Authors: SCHMID PHILLIP G. , ECKSTEIN JOHN W. , ABBOUD FRANCOIS M.
Published: June 2012

Vascular responses to norepinephrine were studied in normal subjects during three sessions. The first session took place before steroid treatment. The second session took place 1 week after daily oral administration of 9-α-fluorohydrocortisone. The third session was conducted 3 weeks after stopping treatment. Forearm blood flow decreased and forearm vascular resistance increased more during norepinephrine infusions in the session immediately after the administration of 9-α-fluorohydrocortisone than in either control session. Increases in resistance against the same levels of blood pressure in the session after steroid treatment indicate that the responsiveness of vascular smooth muscle to norepinephrine was augmented after 1 week of treatment with 9-α-fluorohydrocortisone. The data indicate that blood flow to the forearm during norepinephrine infusion is not enhanced by administration of fluorohydrocortisone.
A Theoretic Model of the T Wave
Authors: HARUMI KENICHI , BURGESS MARY JO , ABILDSKOV J. A.
Published: June 2012

A theoretical model of the T wave based on the sequence of depolarization and multiple action potentials in appropriate time phase has been presented. The methods used to derive T waves and loops from the QRS complex of experimental animals have been described, and derived T waves were closely similar to the T waves recorded from these animals. The findings indicate utility of the model in understanding normal T waves and suggest it may be useful in accounting for abnormal T waves.
Coupled Pacing and Coupled Pacing with Concealed Conduction
Authors: SHEINER LEWIS B. , STOCK RICHARD J.
Published: June 2012

In the case reported coupled pacing via an intracardiac catheter electrode was undertaken and continued for 28 days in order to slow the rapid ventricular response in atrial fibrillation, refractory to drug management and cardioversion.

A new phenomenon was observed in which the coupled stimulus caused cardiac cycle prolongation but elicited neither a mechanical nor a propagated electrical ventricular response. Possible mechanisms of this phenomenon are discussed. Stimulation of the bundle of His or a bundle branch with retrograde, concealed conduction in the A-V node and simultaneous antegrade concealed conduction and block are suggested as the most likely.

When this phenomenon was produced after each consecutive spontaneous depolarization, a reduction in ventricular rate resulted without the production of coupled extrasystolic ventricular depolarizations. This constituted a new coupled pacing technique, termed "coupled concealed pacing."

The long-term effects of this technique and of conventional coupled pacing and paired stimulation in this patient are also reported.
Acute and Chronic Effects of an Adrenergic Beta-Receptor Blocking Agent (Propranolol) in Treatment of Cardiac Arrhythmias
Authors: LURIA MYRON H. , ADELSON EDWARD I. , MILLER ALBERT J.
Published: June 2012

The effects of intravenous and oral administration of propranolol, an adrenergic beta-receptor blocking agent, have been studied in 29 patients with various cardiac arrhythmias. The ventricular responses in chronic or paroxysmal ectopic supraventricular arrhythmias were decreased at rest or during exercise. Sinus tachycardias were regularly slowed. Two supraventricular tachycardias and one ventricular tachycardia, all consistently precipitated by exogenous stimuli, were prevented. Six instances of digitalis-induced arrhythmias were responsive to treatment.

Propranolol, especially when given orally, is of definite value in selected disturbances of cardiac rhythm. Reasonable caution should be exercised, however, because of the risk of precipitation of congestive heart failure or hypotension in patients with limited cardiac reserves.
Anticoagulant Therapy in Coronary Artery Disease
Authors: WESSLER STANFORD , GASTON LAMONT W.
Published: June 2012

Information available at the present time allows the following conclusions to be drawn:

1. Anticoagulant therapy is clearly effective in treating and preventing venous thrombosis and pulmonary emboli.

2. If used in the treatment of acute myocardial infarction, anticoagulant drugs may salvage 3 to 4% of the treated population. This small gain is probably achieved by the prevention of thromboembolic episodes. While only a small percentage of patients are benefited, the actual number of persons salvaged is relatively great because of the large size of the population at risk. In the considerable majority of treated patients who do not benefit from coumarin drugs, the therapy need do no harm, if proper safeguards are employed in the selection of patients and the administration and laboratory control of the drug.

3. In long-term therapy of patients who have recovered from acute myocardial infarction, it appears that men, especially below age 60, may be helped for the first 1 or 2 years after infarction.

4. More data are required to evaluate the role of anticoagulant treatment in patients with angina pectoris or coronary insufficiency. For the present, the physician may reasonably be influenced in the use of anticoagulant therapy by the recent onset of symptoms, the patient's age, and the family history.

5. Although appropriately controlled studies are lacking, it appears as though patients with peripheral emboli secondary to coronary artery disease may be benefited by anticoagulant therapy.
Severe Pulsus Alternans Associated with Primary Myocardial Disease in Children
Authors: HARRIS LEONARD C. , NGHIEM QUANG X. , SCHREIBER MELVYN H. , WALLACE JOHN M.
Published: June 2012

Five children, including two siblings, with clinically similar primary myocardial disease, were studied. One of the siblings expired 3 years after the onset of symptoms, and autopsy showed features of "cardiovascular collagenosis (endocardiomyopathy)." Moderate-to-severe pulsus alternans was present in all cases and persisted even after control of cardiac failure and return to moderate physical activity. No electrical alternans or bigeminy was observed.

Cardiac catheterizations were performed on all patients. Left ventricular volume was radiographically determined in the siblings. Left ventricular end-diastolic volume was calculated as greater, and end-systolic volume smaller, for large beats as compared with small beats. Though alternating, end-diastolic volume was abnormally large, preceding both small and large beats. End-diastolic pressure alternated in the same way. Beat to beat (R-R) interval, alternating by as much as 0.09 second, was equalized by pacing in the right atrium and right ventricle, with persistence of pulsus alternans to a lesser degree. Isovolumetric contraction time was prolonged preceding small beats in spite of the large preceding end-diastolic volumes.

The data appear to be consistent with Starling's law but suggest that impaired contractility, possibly due to alternate deletion of contractile elements, is an additional etiological factor.