bluuebunny/crossref_metadata_2025 huggingface dataset:
Histopathology of Heart Block Complicating Acute Myocardial Infarction
Authors: HUNT DAVID , LIE J. T. , VOHRA JITU , SLOMAN GRAEME
Published: June 2012

Histopathological studies of the conduction system were related to His bundle electrogram recordings in seven patients with acute myocardial infarction and atrioventricular (A-V) conduction disturbances. The three patients with inferior infarctions had normal width QRS complexes and delay or block of the impulses above the His bundle. Recent ischemic changes were present in the A-V node in two cases and in the distal conduction system in all three cases. In the four patients with antero-septal infarction and right bundle branch block (RBBB), either the H-V interval was prolonged or block was present below the H spike. The A-H interval was normal in each of these cases, and the A-V node was not affected by the recent infarction. The right bundle branch was involved in all four of these cases and two patients also had involvement of the left bundle branch. In general there was a good correlation between the sites of heart block as defined by the His bundle electrogram and the histopathological analysis of the cardiac conduction system.
Selective Coronary Arteriography by Percutaneous Left Transaxillary Approach Using Preshaped Torquecontrol Catheters
Authors: PRICE J. EDSON , RÖSCH JOSEF
Published: June 2012

The percutaneous left transaxillary use of preshaped, torquecontrol coronary catheters is considered the technique of choice for selective coronary arteriography in patients with occlusive arterial ileofemoral disease and aortopelvic reconstructive surgery. It affords reliable, selective catheterization of the coronary arteries and their bimodal (cine and serial) examination. Percutaneous left transaxillary selective coronary angiography is a safe and useful technique when performed by experienced and skilled personnel in properly selected patients.
Hemodynamic Effects of Plasma Volume Expansion and Prognostic Implications in Acute Myocardial Infarction
Authors: GREENE H. LEON , KELLY DAVID T. , TAYLOR DEAN R. , PITT BERTRAM
Published: June 2012

Nine of eleven patients studied within fifteen hours from the onset of acute myocardial infarction had an abnormal response to plasma volume expansion in that stroke volume did not increase when left ventricular filling pressure was elevated. In contrast, in five patients studied more than fifteen hours after myocardial infarction and in five control patients stroke volume was increased when left ventricular filling pressure was elevated by plasma volume expansion. All patients have been followed for a mean of five months, and no patient died of pump failure or had significant heart failure. Often the hemodynamic response to plasma volume expansion within fifteen hours after uncomplicated acute myocardial infarction is abnormal, but it is not useful in predicting prognosis. The abnormal hemodynamic response may be transient, improving during early convalescence. It represents an interaction between left ventricular compliance and function, both of which may be changing rapidly early after acute myocardial infarction.
Selection of Patients with Truncus Arteriosus for Surgical Correction
Authors: MAIR DOUGLAS D. , RITTER DONALD G. , DAVIS GEORGE D. , WALLACE ROBERT B. , DANIELSON GORDON K. , MCGOON DWIGHT C.
Published: June 2012

Six years have passed since the first successful surgical correction of truncus arteriosus. A review of our experience enables some conclusions regarding the operation. Patients with mild or moderate truncal valve incompetence do not need truncal valve replacement. Patients with severe truncal valve incompetence require valve replacement, which is associated with a significantly increased surgical mortality. The surgical mortality is not increased in hemodynamically favorable patients who have only one pulmonary artery. However, these patients are especially likely to have early development of severe pulmonary vascular disease. The surgical mortality for the patient with uncomplicated disease and two pulmonary arteries, with pulmonary resistance of less than 8.0 units m
2
, is 10%. In patients with pulmonary resistance between 8.0 and 12 units m
2
, the mortality is approximately three times greater. Patients with pulmonary resistances greater than 12.0 units m
2
are probably inoperable. Different hemodynamic criteria must be applied in assessing the operability of patients with a single pulmonary artery. A systemic arterial oxygen saturation less than 85% in a patient with two pulmonary arteries and without pulmonary artery stenosis or a pulmonary artery band usually indicates inoperability. Elective operation usually is deferred until a patient is four years old, but if the patient's clinical condition warrants, the procedure can be done at any time after the age of one year, with a good chance of success. Follow-up on most operated patients has been encouraging.
Left Ventricular Function and Coronary Artery Anatomy Before and After Myocardial Infarction
Authors: STEWART DOUGLAS K. , HAMILTON GLEN W. , MURRAY JOHN A. , KENNEDY J. WARD
Published: June 2012

Six patients underwent cardiac catheterization before and after occurrence of a myocardial infarction. Results from the two procedures allowed the quantitation of changes in coronary artery anatomy and left ventricular performance associated with myocardial infarction.

Left ventricular biplane or single plane angiography and selective coronary angiography were used to evaluate coronary artery anatomy, left ventricular end diastolic pressure (LVEDP), left ventricular end diastolic volume (LVEDV), end systolic volume (LVESV), and systolic ejection fraction (SEF) under resting conditions.

Four patients had developed occlusion of the artery supplying the area of infarction. In five cases new or progressive contraction abnormalities occurred. One patient had no change in contraction pattern or SEF. Systolic ejection fraction fell in three patients, with no change in LVEDV. In two patients LVEDV rose and SEF fell.

These data demonstrate that a wide spectrum of functional abnormalities is associated with myocardial infarction. Infarction was always associated with significant coronary artery stenosis, but not necessarily associated with occlusion. The SEF and contractile pattern were the indicators of left ventricular dysfunction which most frequently deteriorated.
Left Main Coronary Artery Stenosis
Authors: ZEFT HOWARD J. , MANLEY JACK C. , HUSTON JOHN H. , TECTOR ALFRED J. , AUER JAMES E. , JOHNSON W. DUDLEY
Published: June 2012

Fifty-six patients with severe stenosis of the left main coronary artery underwent coronary bypass surgery between January 1970 and December 1971. All patients had angina pectoris. Seventy-five per cent of the patients had an unstable anginal pattern. There were six perioperative deaths for a surgical mortality of 10.7%. Of the 50 patients surviving surgery, 96% are alive from 12 to 36 months postoperatively, 90% have had a significant reduction in anginal symptoms and 76% are asymptomatic. Postoperative catheterization studies, performed one to 28 months after surgery in 31 patients, showed that 83% of 75 bypass grafts were widely patent. In each patient studied there was at least one widely patent graft to the left coronary artery. Six patients had exercise studies using supine bicycle ergometry during pre- and postoperative cardiac catheterization. These studies demonstrated improvement in exercise tolerance and in left ventricular hemodynamics after coronary surgery.
The Long-Term Follow-Up of Patients Undergoing Saphenous Vein Bypass Surgery
Authors: CANNOM DAVID S. , MILLER D. CRAIG , SHUMWAY NORMAN E. , FOGARTY THOMAS J. , DAILY PAT O. , HU MARIE , BROWN BYRON , HARRISON DONALD C.
Published: June 2012

The results of the first 400 consecutive patients (335 males, 65 females; mean age 52 years) having saphenous vein-coronary artery graft surgery at Stanford between October 1968 and January 1972 were reviewed. Through patient or physician contact, 100% follow-up period was achieved in the 375 patients surviving surgery. The mean follow-up period was 9.9 months, with the range 2 to 40 months. The operative mortality was 6.5%; patients having this surgery electively had a 0.8% mortality. The major cause of operative mortality was myocardial infarction (9 patients) and congestive heart failure and cardiogenic shock (10 patients). Predominant postoperative morbidity was due to pulmonary emboli (17 patients) and intrathoracic hemorrhage requiring thoracotomy (11 patients). The use of anticoagulants in the early postoperative period has reduced the incidence of pulmonary emboli. Angina was completely relieved in 79% (295 patients), 237 of whom had returned to full time employment. However, another 12% either were unchanged from their preoperative symptomatic state or incurred major late complications. This group includes 15 patients (3.9%) who had late deaths from cardiovascular causes. Another 23 patients had late, nonfatal myocardial infarctions. Using as a data base the degree of preoperative congestive heart failure, the extent of electrocardiographic changes and the presence of mitral regurgitation, a prognostic preoperative clinical risk-benefit guideline has been developed for use in any patient undergoing saphenous vein coronary artery graft surgery.
Late Postoperative Conduction Disturbances After Repair of Ventricular Septal Defect and Tetralogy of Fallot
Authors: GODMAN M. J. , ROBERTS N. K. , IZUKAWA T.
Published: June 2012

His bundle electrograms were recorded in five children who developed complete heart block (CHB) five months to five years after cardiac surgery. In four children who had an electrocardiographic pattern of right bundle branch block and left axis deviation (RBBB and LAD) preceding the appearance of CHB, the site of block was distal to the area generating the His potential. The fifth child, who had an electrocardiographic pattern of RBBB with normal axis prior to the development of CHB, had block occurring proximal to the area generating His potential. All five children had had transient CHB in the immediate postoperative period.

In an additional 17 postoperative patients, His bundle recordings were obtained during sinus rhythm. Five out of ten patients with RBBB and LAD on the electrocardiogram and one patient with LBBB had H-V interval prolongation, a recording suggesting incomplete bilateral bundle branch block or trifascicular block. Six patients with RBBB only on the electrocardiogram had normal H-V intervals. All the patients with H-V interval prolongation had had CHB transiently in the immediate postoperative period.

This study suggests that patients with an electrocardiographic pattern of RBBB and LAD who have had transient CHB postoperatively may have, more extensive residual damage to the conduction system than suspected on the basis of the surface electrocardiogram alone and because of the risk of late recurrence of CHB should be given a guarded prognosis.
Changes in Diastolic Stiffness and Tone of the Left Ventricle During Angina Pectoris
Authors: BARRY WILLIAM H. , BROOKER JEFF Z. , ALDERMAN EDWIN L. , HARRISON DONALD C.
Published: June 2012

Reported elevations of left ventricular filling pressures during angina suggest increased myocardial stiffness. Both left ventricular beginning- and end-diastolic pressures and volumes were measured in seven patients before, during, and after angina induced by atrial pacing. During nine episodes of angina, mean end-diastolic pressure rose from 12 to 29 mm Hg and ejection fraction fell from 0.47 to 0.37. Logarithms of beginning and end-diastolic pressures were plotted against the corresponding volumes for each angiogram. During angina, there was a marked increase in beginning as well as end-diastolic stiffness of the ventricle. These changes, which were reversible with resolution of angina, may be due to sustained contraction or failure of relaxation of a portion of the left ventricular myocardium during angina pectoris.
Antiarrhythmic Properties of Chlordiazepoxide
Authors: GILLS RICHARD A. , THIBODEAUX HAROLD , BARR LOUIS
Published: June 2012

The reported effectiveness of chlordiazepoxide in depressing the central nervous system led us to test this agent against cardiac arrhythmias induced by digitalis and coronary occlusion. The digitalis studies were performed in Dial-urethane anesthetized cats by monitoring: (1) ECG, (2) femoral arterial blood pressure, (3) right ventricular contractile force, and (4) spontaneous activity in cardiac sympathetic nerves. Chlordiazepoxide (3.6-39.5 mg/kg i.v.) converted established ventricular arrhythmias induced by deslanoside to regular sinus rhythms in nine of the 12 animals studied. Conversion was associated with depression of deslanoside-induced sympathetic nerve firing. Chlordiazepoxide was ineffective against similar arrhythmias produced in eight spinal-sectioned cats. The coronary occlusion studies were performed in unanesthetized dogs 1 day after two-stage ligation of the anterior descending branch of the left coronary artery. The ECG was recorded and all dogs exhibited ventricular ectopic beats. Chlordiazepoxide (10 mg/kg i.v.) produced a significant reduction in the number of abnormal beats, a significant increase in sinus beats, and a significant degree of cardiac slowing. The effect of chlordiazepoxide on the antiarrhythmic and central nervous system effects of lidocaine was also tested in this preparation. Pretreatment with chlordiazepoxide enhanced the antiarrhythmic effect and prevented the neurotoxic effect of lidocaine. These results support our hypothesis that drugs which depress the central nervous system may be effective for the treatment of ventricular arrhythmias. These results also demonstrate the potential benefit of combining chlordiazepoxide with lidocaine in antiarrhythmic drug therapy.
Reduction in Severity and Extent of Myocardial Infarction When Nitroglycerin and Methoxamine are Administered during Coronary Occlusion
Authors: HIRSHFELD JOHN W. , BORER JEFFREY S. , GOLDSTEIN ROBERT E. , BARRETT MICHAEL J. , EPSTEIN STEPHEN E.
Published: June 2012

The effects of treatment with nitroglycerin (TNG) and methoxamine on the degree of ischemic injury occurring during 5 hours of coronary occlusion were studied in 31 closed-chest sedated dogs. Acute coronary occlusion was produced by inflating a cuff previously implanted around the left anterior descending coronary artery. After 10 min of ischemia (assessed by intramyocardial electrodes), dogs were randomized into control and treated groups. Treated dogs received i.v. TNG during the remainder of the 5 hour occlusion. Arterial pressure was maintained at preinfusion levels with i.v. methoxamine. Six of 16 control dogs died; three of 15 treated dogs died. After 24 hours severity of infarct was assessed in survivors by gross inspection, and more quantitatively, by measurement of creatine phosphokinase (CPK) content of myocardium adjacent to each electrode. Transmural infarction was observed in all of the ten surviving control animals but in only two of the 12 treated animals. In control dogs, CPK was inversely related to ST segment elevation observed after 10 min of occlusion: the greater the ST elevation, the lower the myocardial CPK level. This relation was modified in the treated group: at comparable initial levels of ischemia (as judged by ST segment elevation prior to treatment), treated dogs had significantly less CPK depression than control dogs (
P
< 0.025). Moreover, in controls, a significant reduction in CPK occurred at 48 of 57 electrode sites where ST elevation was observed after 10 min of occlusion. Only 19 of 69 such sites showed significant CPK reduction in the treated dogs (
P
< 0.001). Thus, administration of TNG, with support of arterial pressure by methoxamine, markedly reduces the severity and extent of infarction occurring after 5 hours of coronary occlusion in the dog.
The Posthospital Phase of Myocardial Infarction
Authors: MOSS ARTHUR J. , DECAMILLA JOHN , ENGSTROM FREDERICK , HOFFMAN WILLIAM , ODOROFF CHARLES , DAVIS HENRY
Published: June 2012

A prospective follow-up study was carried out on 100 patients recovering from acute myocardial infarction in order to develop a method for identifying those patients who are at high risk of late cardiac death. Variables, which were recorded just prior to the patient's hospital discharge after the acute attack, included six rhythm parameters from a six-hour tape ECG recording, three indices of severity of the acute coronary event, and seven nonspecific variables. Seventy-nine of the 100 patients survived a two-year follow-up, and 17 of 21 patients who died succumbed from cardiac-related problems. A stepwise discriminant analysis program was used to derive a formula which would predict the likelihood of surviving two years after a myocardial infarction. The population was divided into two groups on the basis of the presence (Group A, N = 67) or absence (Group B, N = 29) of ventricular premature beats on the initial ECG tape recording. In Group A, 91% of both the survivors and nonsurvivors were correctly identified by a discriminant combination of three arrhythmia parameters and age. In Group B, 75% of the survivors and 100% of the nonsurvivors were properly classified simply from age and one index of severity.
Deterioration of Myocardial Function Following Aorto-Coronary Bypass Operation
Authors: SHEPHERD RICHARD L. , ITSCOITZ SAMUEL B. , GLANCY D. LUKE , STINSON EDWARD B. , REIS ROBERT L. , OLINGER GORDON N. , CLARK CHESTER E. , EPSTEIN STEPHEN E.
Published: June 2012

Twenty-two patients underwent cardiac catheterization before and an average of five months after aorto-coronary bypass operation (ACBO). Two groups were examined: 10 patients with all grafts patent, and 12 patients with one or more grafts occluded. All patients improved symptomatically, regardless of graft patency. However, in the occluded group, left ventricular end-diastolic pressure (LVEDP) increased (4.4 ± 2.2 mm Hg,
P
< 0.05), stroke volume index fell (9.8 ± 3.1 ml/m
2
,
P
< 0.05), ejection fraction decreased (10 ± 4%,
P
< 0.05), and left ventricular stroke work index fell (12 ± 3 g-m/m
2
,
P
< 0.01).

Qualitative analysis of segmental left ventricular contractility was performed. Of 28 segments supplied by patent grafts, six improved and nine deteriorated. Of 22 segments supplied by occluded grafts, none improved and eight deteriorated. Frequently no angiographically demonstrable basis for the segmental deterioration was evident.

We concluded that while ACBO may appreciably benefit severely symptomatic patients, our results do not substantiate the claim that ACBO should be recommended when the primary surgical goal is preservation or enhancement of myocardial function.
Natural History of Ischemic Heart Disease in Relation to Arteriographic Findings
Authors: HUMPHRIES J. O'NEAL , KULLER LEWIS , ROSS RICHARD S. , FRIESINGER GOTTLIEB C. , PAGE E. EUGENE
Published: June 2012

The severity of the atherosclerotic disease of the coronary arteries is demonstrated to be an important predictor of survival in a group of 224 patients followed from 5 to 12 years after coronary arteriography. The group consisted of young patients (average age 41.8 years) without hypertension or congestive heart failure, who were studied during the stable phase of their disease. The current status of 218 or 97% of this group of patients is known.
Electrophysiologic Effects of Procaine Amide in Patients with Intraventricular Conduction Delay
Authors: SCHEINMAN MELVIN M. , WEISS ALAN N. , SHAFTON EUGENE , BENOWITZ NEAL , ROWLAND MALCOLM
Published: June 2012

In 16 patients with intraventricular conduction delay (IVCD) and cardiac arrhythmias, procaine amide (PA) was infused intravenously at rates of 30-40 mg/min until a maximum dose of 750-1,000 mg was administered. His bundle electrograms and plasma PA levels were obtained every 5 min during infusion and for 25 min thereafter. The mean peak PA level (10.2 ± 3.4 µg/ml) was achieved at the end of infusion. Mean control A-V nodal conduction times (A-H: 99.5 ± 34 msec) and A-H at peak PA levels (90 ± 15.3) did not differ significantly. However, the mean infranodal conduction time (H-Q) at peak PA (68.1 ± 14.8 msec) was significantly higher than control measurements (57.6 ± 13 msec) (
P
< 0.001), with a mean percent increase of 18% (11 msec), and maximal prolongation of H-Q occurred at peak PA blood levels. There was no statistically significant correlation between maximum absolute or percent change in H-Q and control H-Q, control QRS duration, or peak PA levels. One patient with sinus bradycardia had further decreases in rate and a junctional rhythm after PA. Intravenous administration of PA appears safe and effective for patients with IVCD in terms of arrhythmia control and absence of high degree A-V block, ventricular ectopic beats, or standstill, but caution should be used in treating patients with sinus bradycardia.
The Metabolic and Hemodynamic Effects of Prolonged Bed Rest in Normal Subjects
Authors: CHOBANIAN ARAM V. , LILLE ROBERT D. , TERCYAK ANN , BLEVINS PENGWYNNE
Published: June 2012

The metabolic and hemodynamic effects of prolonged bed rest were studied in 6 normal subjects. Bed rest of 2-3 weeks duration produced exaggerated responses of heart rate, cardiac output, stroke volume, and peripheral vascular resistance to 70° tilt. Sympathetic nerve function and catecholamine metabolism were not impaired by bed rest. Pressor responses to infusions of norepinephrine and angiotensin and reflex vasoconstriction to a cool and warm environment were essentially unchanged during bed rest. Plasma catecholamines and urinary vanillylmandelic acid excretion were somewhat lower during bed rest than during ambulation, but the response of plasma catecholamines to 70° tilt was not diminished. The apparent turnover of norepinephrine in plasma was also similar in bed rest and control periods. Negative sodium and potassium balances and reductions in plasma volume were observed in all subjects, but plasma renin activity and aldosterone secretory rate showed no significant change. The major decreases in sodium balance and plasma volume occurred in the early bed rest period and did not correlate closely with the degree of orthostatic intolerance. The reductions in potassium balance appeared to be progressive throughout the study.
Common (Single) Ventricle with Normally Related Great Vessels
Authors: MARÍN-GARCÍA JOSÉ , TANDON RAJENDRA , MOLLER JAMES H. , EDWARDS JESSE E.
Published: June 2012

A rare form of common ventricle with normally related great vessels and normal tricuspid and mitral valves should be considered in the differential diagnosis of cardiac anomalies presenting with cyanosis. Fourteen cases of this type of common ventricle were studied; in seven the diagnosis was made at necropsy and in seven it was based on angiographic evidence. That the common ventricle was morphologically a left ventricle was determined in the seven necropsy cases, and angiocardiographic examination confirmed the finding in the others. Continuity of the aortic valve and the mitral valve was observed in all the necropsy cases and in five of the clinical cases. Cyanosis had been observed clinically in 13 of the 14 cases, and pulmonary stenosis was present in four necropsy and three clinical cases. Electrocardiograms showed left axis deviation in nine of the 13 cases studied. Vectorcardiographic findings, though variable and available in only seven cases, tended to show a narrow horizontal plane QRS vector loop in patients with restricted pulmonary blood flow and a wide loop in those with increased pulmonary flow.

The clinical, laboratory, and pathologic findings are reported and the differential diagnosis and the profile of the condition are considered.
Corrected Transposition of the Great Arteries
Authors: KINSLEY ROBIN H. , MCGOON DWIGHT C. , DANIELSON GORDON K.
Published: June 2012

Two patients with corrected transposition of the great arteries and ventricular rotation are described. The ventricular rotations encountered were about the longitudinal and the anteroposterior axes, respectively. The ventricular rotation affected the plane of the ventricular septum, the inflow and outflow tracts of the ventricles, and the interrelationship of the great arteries. Surgical closure of an associated ventricular septal defect was not without its problems.
Echocardiography in Coexisting Hypertrophic Subaortic Stenosis and Fixed Left Ventricular Outflow Obstruction
Authors: CHUNG KYUNG J. , MANNING JAMES A. , GRAMIAK RAYMOND
Published: June 2012

Echocardiographic study was done on four pediatric patients with coexisting hypertrophic subaortic stenosis (HSS) and fixed left ventricular outflow (LVO) obstruction. One had valvar aortic stenosis, two had discrete subaortic stenosis and one had coarctation of the aorta. Preoperatively, HSS was not suspected in any of these patients because of the classical findings of fixed LVO obstruction. The echocardiographic examination revealed an abnormal systolic anterior movement (SAM) of the anterior mitral leaflet with ventricular septal hypertrophy in all, but these findings were overlooked or thought to be related to a subvalvar diaphragm. One or two years after the surgical removal of their fixed obstruction, all showed clinical pictures of HSS. Postoperative echocardiographic examination showed an abnormal SAM with asymmetrical septal hypertrophy, and cardiac catheterization revealed mild to severe degrees of resting pressure gradients across LVO tracts. Amyl nitrite inhalation produced a more prominent SAM with increasing pressure gradient, and angiotensin infusion abolished the SAM and reduced the pressure gradient.

From our present study, echocardiography has the potential for identification of HSS coexisting with a fixed LVO obstruction. We recommend that all patients with LVO obstruction have an echocardiographic examination along with pharmacological testing. The demonstration of an unusually thickened ventricular septum and especially, abnormal SAM of the mitral valve would require careful evaluation of left heart hemodynamics and the determination of the level of the major obstruction during cardiac catheterization for pre and postoperative management.
Cardiovascular Mechanisms of Functional Aerobic Impairment in Patients with Coronary Heart Disease
Authors: BRUCE ROBERT A. , KUSUMI FUSAKO , NIEDERBERGER MANFRED , PETERSEN JOHN L.
Published: June 2012

Maximal oxygen uptake V

O
O2
max

) and functional aerobic impairment (FAI) were determined by treadmill test in 42 men with coronary heart disease and in 11 slightly older healthy men. Patients were separated according to occurrence or nonoccurrence of angina with exercise. At rest and at four levels of submaximal exercise on a bicycle ergometer, cardiac output (Q), using the direct Fick principle, heart rate (HR), mean systemic and pulmonary arterial pressures, and arterial-mixed venous oxygen difference (A-V O
2
D) were evaluated in relation to relative aerobic requirement (% V

o
o2
max

). Q was highly correlated with V

o
o2

, and both the level and the rate of change of Q were lower in patients with angina at all submaximal workloads. Stroke volume (SV) and HR were significantly restricted at the higher workloads. Although peripheral resistance was increased, there was no compensatory increase in A-V O
2
D. Both restricted SV and reduced HR are responsible for cardiovascular components of the abnormal FAI found in patients with myocardial ischemia due to coronary arterial disease.
Impaired Left Ventricular Function in Alcoholic Cirrhosis With Ascites
Authors: LIMAS CONSTANTINOS J. , GUIHA NABIL H. , LEKAGUL OSOTH , COHN JAY N.
Published: June 2012

Left ventricular function was assessed in 10 patients with alcoholic cirrhosis and ascites without clinical evidence of heart disease. In the resting state pulmonary wedge pressure (PWP) was normal (average 9.7 mm Hg), cardiac output (CO) was elevated (average 9.7 L/min) and systemic vascular resistance (SVR) was low (average 825 dynes-sec-cm
–5
). During infusion of angiotensin in a dose sufficient to raise diastolic arterial pressure 20 mm Hg, SVR increased to 1140 dynes-sec-cm
-5
(
P
< 0.01) and PWP rose to 19.2 mm Hg (
P
< 0.001) with no change in CO. Resting hemodynamics were essentially unchanged in seven patients restudied 45-60 min after intravenous administration of 0.5 mg ouabain. Repeat infusion of angiotensin after ouabain again resulted in a rise in PWP to an average of 17.0 mm Hg (
P
< 0.001) with no significant change in CO. In seven additional cirrhotic patients with ascites, systolic time intervals were unchanged by 0.5 mg ouabain whereas in four normal volunteers the same dose resulted in significant shortening of total electromechanical systole, pre-ejection period and left ventricular ejection time. These data indicate that depression of the left ventricular response to an increase in afterload is a uniform finding in alcoholic patients with cirrhosis and ascites. The absence of clinical symptoms of heart disease, therefore, could be attributed to the low systemic vascular resistance characteristic of cirrhosis. Since acute administration of ouabain neither improved left ventricular function nor altered systolic time intervals, digitalis may have a limited place in the therapy of this form of cardiac impairment.
Relationships Between Increased Automaticity and Depressed Conduction in the Main Intraventricular Conducting Fascicles of the Human and Canine Heart
Authors: ROSENBAUM MAURICIO B. , ELIZARI MARCELO V. , CHIALE PABLO , LEVI RAÚL J. , NAU GERARDO J. , HALPERN M. SUSANA , LÁZZARI JULIO O. , NOVAKOVSKY ALEJANDRO
Published: June 2012

Escapes from the injured fascicle (EIF) were investigated in 281 cases of bundle branch block (BBB), and during 35 experiments in which rate-dependent BBB was provoked in the intact canine heart. During vagal stimulation, EIF occurred in 27 of the 35 canine experiments, in seven of 24 patients with phase 4 (bradycardia-dependent) BBB, and in nine of 31 patients with fixed BBB. Changes in the degree of fascicular injury and phase 4 BBB were accompanied by correlative changes in the frequency and coupling interval of the EIF, indicating the existence of a close relationship between degree of injury, phase 4 BBB and EIF or enhanced automaticity within the affected fascicle. Therapeutic doses of isoproterenol and lidocaine were tested and were shown to have a simultaneous and sometimes concordant effect on the BBB and the EIF. Occasionally in the acute experiments on dogs, commonly in chronic patients, or at times in patients under the effects of lidocaine, a dissociation or desynchronization between the phase 4 BBB and the EIF was documented. This dissociation implies the existence of other physiologic factors, which may eventually cause the occurrence of concealed or abortive escapes. The fact that phase 3 (tachycardia dependent) and phase 4 BBB can be identified in patients or provoked experimentally in the intact canine heart, with or without EIF, provides with a model of great potential value for studying effects of antiarrhythmic drugs.
Left Ventricular Hypertrophy Patterns and Prognosis
Authors:   THE CORONARY DRUG PROJECT RESEARCH GROUP
Published: June 2012

Electrocardiographic evidence of left ventricular hypertrophy (ECG-LVH), defined only by elevated R wave amplitudes in appropriate leads of the resting ECG, was ascertained among 2,760 survivors of myocardial infarction who had been randomized into the placebo-treated group of the Coronary Drug Project. The entry ECG findings were related to the subsequent three-year mortality. Of 2,760 men, 186 (6.7%) had ECG-LVH amplitude criteria in the baseline ECG when taken after at least three months survival (average, 36 months) from the last myocardial infarction.

Three-year mortality in men with ECG-LVH was almost twice that in men without ECG-LVH (22.6% vs 12.1%;
P
= 0.0002) when the "effect" of all other variables on mortality was ignored. However, when the relationship between baseline ECG-LVH and subsequent mortality was adjusted, using a multivariate analysis, for other electrocardiographic and clinical findings, elevated R amplitude itself had no significantly independent prognostic importance. The prognostic importance of ECG-LVH was largely explained by coexisting repolarization abnormalities, although ECG-LVH plus abnormal ST-segment and T wave findings had a less favorable prognosis than ST-segment and T wave abnormalities alone. ECG-LVH by R wave amplitude criteria in the absence of abnormal ST-segment and T wave findings was unrelated to prognosis in these postinfarct patients.
Effect of Propranolol on Oxygen Binding to Hemoglobin
In Vitro
and
In Vivo
Authors: LICHTMAN MARSHALL A. , COHEN JULES , MURPHY MARION S. , KEARNEY ELIZABETH A. , WHITBECK APRIL A.
Published: June 2012

We have shown that propranolol reduces oxygen binding by hemoglobin in intact red cells by increasing the selective permeability of the red cell membrane resulting in an exodus of potassium, chloride, and water. The latter effects result in a new distribution of hydrogen ion between cell and plasma, and thereby a reduction in red cell pH. The reduction in pH can fully explain the change in hemoglobin's affinity for oxygen based on the Bohr effect. Either D- or DL-propranolol can produce the change in red cell pH and oxygen binding by hemoglobin. The drug action on permeability is not prevented by epinephrine, although it is by chlorbutanol. Hence, the membrane action of propranolol does not appear to be related to its activity as a beta-adrenergic receptor blocking agent.

Propranolol produced a marked alteration in red cell shape as well as in hydration (hypovolumic stomatocytes). The two effects were separable since dehydration of the cell by the addition of sucrose to plasma did not result in stomatocytes and chlorbutanol blocked the enhancement of permeability of the red cell membrane by propranolol without preventing the shape change (isovolumic stomatocytes). This suggests that propranolol may have two separate sites of membrane interaction.

Propranolol (10 to 360 mg) administered to human subjects did not affect hemoglobin-oxygen affinity. This is explained by the fact that the concentration in blood after such doses is nearly 4,000 to 100-fold lower than that required to achieve changes in blood
in vitro.
Evaluation of Left Ventricular Performance
Authors: BENZING GEORGE , STOCKERT JAMES , NAVE EDWIN , KAPLAN SAMUEL
Published: June 2012

In the first part of the study, the influence of changes in preload and afterload on mean circumferential fiber shortening velocity, Vcf, was investigated in the absence of any extrinsic cause for change in the contractile state of the left ventricle (LV) of seven dogs. In five of seven dogs in which afterload was controlled and contractility was unchanged, there was a significant negative correlation between LV end-diastolic pressure and mean Vcf expressed in circumferences per second (
r
= –.88 to –.97). In one dog there was a positive correlation (
r
= +0.847) and in another dog there was no significant correlation. Correlation as a group was poor.

In five of the above seven dogs in which afterload was decreased from a control level while preload was controlled and contractility was not extrinsically altered, mean Vcf increased in all instances. Because of the influence of afterload on Vcf increased in all instances. Because of the influence of afterload on Vcf and the inconsistent relation between Vcf and preload, we controlled preload and afterload during assessment of Vcf in reflecting a change of LV contractility.

Since mean left ventricular hydraulic output power, MLVP, quantitates practically all of the mechanical power of the left ventricular musculature, MLVP was utilized to represent the contractile state of the left ventricle under conditions in which preload and afterload were controlled. Mean and peak Vcf, Vcf at peak tension, extent of circumferential fiber shortening, and peak tension were compared with MLVP to test their usefulness in reflecting a change in the contractile state of the LV.

Twenty dogs were divided into four groups of five each. Group I was exposed to cardiopulmonary bypass alone. Dogs of groups II, III, and IV were exposed to a total of 45 minutes of myocardial ischemia during bypass. After bypass, groups I, II, III and IV retained an average of 89.3, 79.9, 82.5 and 69.2% of the control or original mean Vcf, and 87.1, 63.9, 53.4 and 33.5% of the control MLVP, respectively. Although an effect of ischemia was detected by changes of peak tension and extent of fiber shortening, the statistical evidence was less satisfactory than observed for MLVP. It was concluded that mean Vcf, peak Vcf, and Vcf at peak tension are inadequate indices to detect acute changes in the contractile state of the LV produced by prior myocardial ischemia. These same changes in contractility are readily determined by MLVP.
Congenital Mitral Valve Disease Associated with Coarctation of the Aorta
Authors: ROSENQUIST GLENN C.
Published: June 2012

Fifty-three specimens in which the primary diagnosis in life was coarctation of the aorta were examined; only nine had a mitral valve of normal size and configuration. Ten specimens had a normally formed valve mechanism which was small in comparison to both tricuspid valve and left ventricle. Three other specimens had a normally formed but small valve which exhibited a short free margin of the anterior leaflet. The remaining 31 specimens demonstrated various anomalies which included some forms of parachute mitral valve. The spectrum of malformations may be divided into three basic types: some showed fused or closely apposed chordae tendineae, due to nondevelopment of the intervening space; in others the space between the papillary muscles and the ventricular wall was underdeveloped, which prevented the papillary muscles from moving independently of the ventricular wall. The third type was found in a case of parachute mitral valve, where the chordae tendineae were attached solely to the anterolateral papillary muscle, and the posteromedial papillary muscle was inserted directly into the valve, near the annulus. Although the spectrum of congenital anomalies reported here does not include all forms of mitral stenosis, it does indicate that mitral valve disease probably occurs more frequently in coarctation of the aorta than previously was recognized.
Comparison of Serum Digoxin Level Measurement with Acetyl Strophanthidin Tolerance Testing
Authors: KLEIN MICHAEL D. , LOWN BERNARD , BARR ISAAC , HAGEMEIJER FRANS , GARRISON HENRY , AXELROD PAUL
Published: June 2012

Serum digoxin levels (SDL) were compared with tolerance for the rapidly acting cardiac aglycone, acetyl strophanthidin (AS). AS titration tests were performed on 133 patients with diverse cardiac disorders. All were receiving maintenance digoxin. Both exquisite AS sensitivity and tolerance for a 1.0 mg AS were associated with a wide range of SDL values. Concordance and discordance between the two methods in assessing degree of digitalization were evaluated by considering SDL of 1.4 ng/ml to be the mean value for patients without glycoside-induced cardiac arrhythmia. An SDL of < 1.5 ng/ml with tolerance for 1.0 mg AS and an SDL of > 1.4 ng/ml with sensitivity to 1.0 mg AS or less constituted concordant responses. An SDL of < 1.5 ng/ml with intolerance for 1.0 mg or less AS and an SDL of > 1.4 ng/ml with tolerance for 1.0 mg AS comprised discordant responses. In 60 of 144 (42%) AS titrations discordant results were observed. Severe pulmonic, coronary, and aortic valvular heart disease, as well as old age, contributed to unusual AS sensitivity. Titration with AS clarified pharmacologic quantification of SDL by providing insight into optimum therapeutic glycoside dose.
Coronary Perfusion Versus Cold Ischemic Arrest During Aortic Valve Surgery
Authors: SAPSFORD RALPH N. , BLACKSTONE EUGENE H. , KIRKLIN JOHN W. , KARP ROBERT B. , KOUCHOUKOS NICHOLAS T. , PACIFICO ALBERT D. , ROE CHARLES R. , BRADLEY EDWIN L.
Published: June 2012

Sixty-four randomized patients undergoing primary, isolated, scheduled, prosthetic aortic valve replacement were studied to determine the safety of coronary perfusion and mild hypothermia (31 patients) and of cold ischemic arrest (33 patients). Cardiac performance, metabolism, and isoenzyme release and the electrocardiogram were studied early postoperatively. No differences greater than expected by chance were found between the two groups; however, the difference between group means of several hemodynamic variables was significantly larger than experimental error. Combined abnormalities of creatine phosphokinase (CPK) and lactic dehydrogenase (LDH) heart-specific isoenzymes, indicative of myocardial necrosis, were found in 33 of 48 patients (68.7%) so studied. The incidence was similar in both study groups. In 14 of 52 (27%) patients with electrocardiographic studies, changes indicative of new infarction or ischemia were demonstrated, but no differences in incidence between the two groups of patients were found. In both groups the transmyocardial excess lactate immediately postoperatively was elevated, falling to near normal over the next 24 hours. Aortic crossclamp and cardiopulmonary bypass times were less by 27% and 21% respectively when cold ischemic arrest was used.
The Missing Waveform Information in the Orthogonal Electrocardiogram (Frank Leads)
Authors: KORNREICH F. , BLOCK P. , BRISMEE D.
Published: June 2012

A new lead system recording nine surface ECGs was found capable of resynthesizing in each patient all the QRS waveforms recorded on the thoracic surface. Observations were made in 416 patients: 150 normal (N) individuals, 95 patients with left ventricular hypertrophy (LVH), 97 patients with right ventricular hypertrophy (RVH), and 74 patients with biventricular hypertrophy (BVH). After time-normalization and division of the nine waveforms into eight equal parts, 72 variables were determined for each patient. Recordings from Frank XYZ leads were also available for each subject. After time-normalization and division in eight equal parts, 24 variables were obtained from Frank lead recordings in each individual.

The 72 variables from the new system and 24 variables from the Frank leads were then submitted to multivariate statistical procedures in order to differentiate BVH from N, LVH, and RVH. Four parameters were finally retained — for both the 9-lead system and the Frank leads — as the best discriminators for the separation of BVH from normal, BVH from LVH, and BVH from RVH. The diagnostic performances, defined as ½ (specificity + sensitivity), were 93.5%, 85%, and 81%, respectively, for the 9-lead system and 88.5%, 69%, and 75% for the Frank leads. The repeatability of the results was tested on independent control samples and found reasonable.

The limited clinical use of independent pairwise comparisons is discussed and the alternative of stepwise pairwise comparisons following a decision tree is proposed. Some deterioration in the final classification is noticed; the recognition rates are 90% for normal, 79% for LVH, 75% for RVH and 73% for BVH (average 79%) with the 9-lead system, and 90% for N, 55% for LVH, 46% for RVH and 59% for BVH (average 62%) with the Frank leads.
Acute Atypical Coronary Artery Insufficiency
Authors: LITTMANN DAVID , BARR J. H.
Published: June 2012

Not all patients with acute coronary thrombosis or inadequacy develop classic myocardial infarction. Almost 30 per cent of such patients were found to have atypical and apparently less extensive myocardial injury as estimated by the clinical and electrocardiographic findings. The morbidity as well as the mortality was of a lesser order and a somewhat different therapeutic regimen could be employed.
Factors Influencing Cerebral Blood Flow and Metabolism
Authors: SCHEINBERG PERITZ , JAYNE HAROLD W.
Published: June 2012

The results of studies utilizing the nitrous oxide technic for measuring cerebral blood flow have been reviewed and divided into three groups: (1) those in which cerebral blood flow and metabolism were normal, (2) those in which cerebral blood flow was increased, and (3) those in which cerebral blood flow and metabolism were decreased. The factors which apparently regulate and control cerebral blood flow and metabolism are reviewed and discussed.
Alcohol Vapor by Inhalation in the Treatment of Acute Pulmonary Edema
Authors: LUISADA ALDO A. , GOLDMANN MORTON A. , WEYL RUTH
Published: June 2012

Accepted therapy of pulmonary edema is contraindicated in shock, central nervous system lesions, or pregnancy. Diagnosis of the underlying disease is not always immediately possible. Alcohol inhalation, previously tested in animals, changes surface tension of the foam and has beneficial effects. Clinical experience has revealed prompt relief in over one-half of the acute cases, definite improvement in another 29 per cent. Some cases with subacute edema also exhibited decreased foaming. The absence of contraindications and the possibility of using the method in conjunction with other procedures are favorable elements of alcohol therapy by inhalation.
The Peripheral Vascular Reactivity of Potassium-Deficient Rats
Authors: ROSENMAN RAY H. , FREED S. CHARLES , FRIEDMAN MEYER
Published: June 2012

Peripheral vascular reactivity was studied in the potassium-deficient and control rats by measuring the degree of blood pressure response to intravenously injected pressor substances. The pressor response consistently was less in the potassium-deficient rats. The significance of these results with regard to the hypotensive action of potassium deprivation is discussed.
The Effects of Intravenous Procaine and Procaine Amide (Pronestyl) upon Ectopic Ventricular Tachycardia Accompanying Acute Myocardial Infarction
Authors: HARRIS A. SIDNEY , ESTANDÍA ANTONIO , FORD TEDROE J. , SMITH HERBERT T. , OLSEN ROY W. , TILLOTSON REX F.
Published: June 2012

In tests using dogs with ectopic ventricular tachycardia resulting from myocardial infarction,
procaine
has been found to be without practical value as an ectopic impulse suppressor agent.
Procaine amide
has proved to be very effective in reducing the ectopic rate of high frequency tachycardias to low levels, thus eliminating danger of death from the tachycardia. Procaine amide usually does not produce an entirely normal rhythm but this is of little practical importance. The toxicity of procaine amide is relatively low. For approximately equivalent results, in the tachycardias studied, the dosage of procaine amide must be two to three times that of quinidine.
Spontaneous Atherosclerosis in the Rabbit
Authors: BRAGDON JOSEPH H.
Published: June 2012

Microscopic lesions interpreted as representing early atherosclerosis were found in the aortas of most suckling rabbits. This is a period characterized by relatively high plasma lipid levels. In the postweaning period the lesions regressed. Fresh lesions reappeared in a significant number of adult rabbits of both sexes. Correlation with plasma lipid levels in the adult is less conclusive.
Tissue Cations and Water in Arterial Hypertension
Authors: TOBIAN LOUIS , BINION JOHN T.
Published: June 2012

Human hypertensive subjects were found to have an increased sodium and water concentration in renal artery and psoas muscle. Hypertensive rats showed a high water content in their aortas. If the water and sodium content were increased in hypertensive arterioles as well as arteries, the swelling of the arteriolar walls would narrow the lumens enough to account for much of the increased peripheral resistance. Low sodium diets may alleviate hypertension by lowering the sodium and water contents in arteriolar walls toward normal values.
Death in Potassium Deficiency
Authors: KEYE JOHN D.
Published: June 2012

Autopsy of a patient with the sprue syndrome dying in hypokalemia revealed the myocardial and renal lesions of potassium deficiency. Similar renal changes are described under various names in the recent literature. It is suggested that they result from potassium deficiency since they occurred in patients who died with disorders commonly associated with electrolyte imbalance.