bluuebunny/crossref_metadata_2025 huggingface dataset:
Acute Severe Mitral Regurgitation from Papillary Muscle Dysfunction in Acute Myocardial Infarction
Authors: CHENG TSUNG O. , BASHOUR TALI , ADKINS PAUL C.
Published: June 2012

A patient with acute severe mitral regurgitation resulting from papillary muscle dysfunction which developed on the third day of acute myocardial infarction underwent early successful mitral valve prosthetic replacement with concomitant aortocoronary saphenous vein bypass. The concept of acute severe mitral regurgitation due to an infarcted papillary muscle which has not actually ruptured and an aggressive approach to such a catastrophic event early in the course of acute myocardial infarction are emphasized. The risk is well worth the gratifying result obtained in our patient who successfully underwent such a combined operative procedure for one of the early complications of acute myocardial infarction.
Reversible Complete Heart Block following Cardiac Surgery
Authors: ANDERSON PAGE A. W. , ROGERS MARK C. , CANENT RAMON V. , JARMAKANI JAY M. M. , JEWETT PAUL H. , SPACH MADISON S.
Published: June 2012

His bundle electrograms were recorded before and throughout the postoperative course in two children who developed temporary complete heart block after surgical correction for tetralogy of Fallot. In one the complete heart block was associated with prolonged duration of the QRS complex, and in the other there was no prolongation of the QRS complex. His bundle electrograms in the patient with widened QRS identified the site of block to be between the low atrium and the His bundle, and in the patient with a QRS of normal duration the block was distal to the His bundle. Complete heart block disappeared within 3 weeks in both patients. Subsequent His bundle studies showed normal A-V conduction in the first patient except for the presence of persistent complete right bundle-branch block. In the other, prolongation of the P-R interval was persistent, and atrial pacing at high rates produced a Wenckebach type of block distal to the His bundle. These studies indicate that electrophysiologically the site of complete heart block following definitive intracardiac surgery can occur at multiple sites. Furthermore, in complete heart block the site of the pacemaker may not be accurately predicted from routine electrocardiograms alone, and His bundle recordings may be necessary to clarify this site.
Decreased Reactivity of Lymphocytes in Mixed-Leukocyte Culture from Patients with Rheumatic Fever
Authors: LUEKER RICHARD D. , WILLIAMS RALPH C.
Published: June 2012

The purpose of this study was to evaluate cellular immune responsiveness. in patients with acute rheumatic fever (ARF). Peripheral blood lymphocytes were obtained for culture from patients who had ARF within the past 2-3 months. No patient was receiving steroids at the time of the study. Peripheral lymphocytes were also obtained from normal control individuals.

Lymphocyte cultures were maintained for 7 days in minimum essential medium with 10% fetal calf serum in a 5% CO
2
environment. Cellular responsiveness was checked concomitantly with pokeweed mitogen and/or phytohemagglutinin. Mixed-lymphocyte cultures were studied between patients with ARF and between patients with ARF and normal controls. Normal responses were arbitrarily defined as a threefold increase over baseline counts.

ARF cells were capable of stimulating other ARF cells in only three of 14 instances and were able to stimulate control cells in only three of 11 studies. Conversely, ARF lymphocytes were capable of being stimulated by control normal cells in five of 10 experiments. Thus decreased cellular responsiveness and abnormalities in cellular immunity are present in many patients with ARF, since lymphocytes from patients with ARF are usually incapable of stimulating normal or other ARF cells. However, ARF cells are capable of being stimulated by normal control cells in 50% of studies performed.
Assessment of Sinus Node Function in Patients with the Sick Sinus Syndrome
Authors: MANDEL WILLIAM J. , HAYAKAWA HIROKAZU , ALLEN HOWARD N. , DANZIG RONALD , KERMAIER ALAN I.
Published: June 2012

Thirty-one patients with symptomatic sinus node dysfunction were evaluated with electrocardiograms, Holter monitor recordings, exercise, isoproterenol infusions, atropine administration, Valsalva maneuvers, carotid sinus massage, and overdrive pacing. Four basic clinical subsets were recognized: (1) carotid sinus hypersensitivity (2) bradycardia-tachycardia syndrome, (3) episodic sinus arrest, and (4) persistent symptomatic sinus bradycardia. The study group demonstrated a normal heart rate response to exercise and isoproterenol infusion (%Δ = +95 exercise, +144 isoproterenol) in the face of diminished responsiveness to atropine administration (%Δ = +23). Marked carotid sinus hypersensitivity was demonstrated in eight patients, and four patients demonstrated slight abnormalities during performance of Valsalva maneuvers. Significant suppression of sinus node dysfunction was observed following atrial overdrive in the study group (postpacing pause = 3087 ± 464 msec) as compared to patients without significant sinus node function (postpacing pause = 1073 ± 63 msec) (
P
< 0.001). In patients with intact V-A conduction, ventricular overdrive also resulted in sinus node suppression (postpacing pause = 1901 ± 357 msec). There was a marked decrease in the degree of sinus node depression following atropine administration. Ten of 31 patients demonstrated various degrees of A-V block following atrial pacing at rates less than 100 beats/min.

It is concluded that the present methods of evaluation of sinus function, especially sinus node recovery time following overdrive pacing, may prove of value in the investigation of patients with syncope of unknown etiology.
Coexistence of Single Ventricle with Atresia of One Atrioventricular Orifice
Authors: QUERO MANUEL
Published: June 2012

A new case of an unusual association of mitral atresia with single left ventricle is reported. The salient anatomic features include: (1) the right atrioventricular valve is atretic; (2) the left atrioventricular valve enters the large ventricle with morphologic characteristics of the left ventricle; and (3) this large ventricle communicates by way of an interventricular communication with a smaller left-sided ventricle, but with the morphologic characteristics of the right ventricle. Guidelines for the recognition of these uncommon malformations are given.
Axillary Arteriovenous Fistula
Authors: GLENN WILLIAM W. L. , FENN JOHN E.
Published: June 2012

A right axillary A-V fistula has been made in a 13-year-old patient with tricuspid atresia who, after undergoing two unsuccessful attempts in infancy to establish a left Blalock shunt and having had a superior vena cava-right pulmonary artery (SVC-RPA) shunt at age 3, showed increasing disability and profound cyanosis (HCT 80%). One year following creation of the fistula there is marked increase in exercise tolerance, a decrease in HCT to 56%, and an increase in pO
2
from 57 to 105 mm Hg.

Creation of an axillary A-V fistula in patients with an SVC-RPA shunt is an effective means of supplementing blood flow to the right lung by increasing the flow through the shunt and by giving it a pulsatile character, and, eventually, by decreasing the blood's viscosity. Axillary A-V fistula may be required by many patients with a cava-pulmonary shunt who have inadequate perfusion of the contralateral lung and clinical deterioration.
Significance of Chronic Sinus Bradycardia in Elderly People
Authors: AGRUSS NEIL S. , ROSIN ELAINE Y. , ADOLPH ROBERT J. , FOWLER NOBLE O.
Published: June 2012

It may be difficult to evaluate sinus bradycardia in the elderly since sinus rates below 50 beats/min may occur normally with aging. Seven asymptomatic bradycardic subjects (heart rates 41-51 beats/min), ages 67-79 years, with no evidence of impaired cardiac performance and taking no drugs, were compared with four age-matched controls (heart rates 60-84 beats/min). Autonomic function was tested with the Valsalva maneuver, amyl nitrite inhalation, methoxamine infusion, head-up tilt, and atropine intravenously (2 mg).

Cardiac index at rest was normal in bradycardic subjects (2.4 ± 0.1
sem
); increased cardiac stroke volume (SV) compensated for the slow heart rate. With supine bicycle exercise, increase in cardiac output per 100 ml increase in oxygen consumption was normal in bradycardics (885 ± 60 ml compared to 907 ± 171 ml in controls). This exercise response was achieved mainly by increased SV in bradycardics and by increased heart rate in controls. Significant increases in cardiac output occurred with both atropine and atrial pacing in bradycardics, but not in controls. Autonomic impairment was not found. Increased vagal tone in bradycardics was suggested by a lesser heart rate response to exercise and passive tilting.

Hence, a heart rate below 50 beats/min in elderly people does not necessarily indicate depressed cardiac performance. Further evaluation of the significance of bradycardia in these subjects requires long-term observation.
Induced Hypertension in the Treatment of Severe Ischemia of the Foot
Authors: HANSTEEN VIGGO , LORENTSEN EINAR
Published: June 2012

The present paper reports the results of angiotensin infusion in 11 patients with severe atherosclerosis of the lower limbs adding a brief discussion of indications with inherent dangers and contraindications.

The study confirms the results of Dahn et al.
4,5
that pharmacologically induced hypertension may increase distal perfusion pressure and flow and relieve resting pains. It is our opinion, however, that only a very limited number of patients presenting with severe foot ischemia and resting pains can profit from this treatment because of frequent contraindications such as coexistent hypertension and coronary heart disease.
Tritiated Digoxin XVIII
Authors: DUNGAN W. T. , DOHERTY J. E. , HARVEY C. , CHAR F. , DALRYMPLE G. V.
Published: June 2012

Tritiated digoxin turnover studies were performed in nine children aged 4 days to 7 years. Mean serum turnover time was 32.5 (range 18-48) hours, and the 3-day urine and stool excretion was 55% of the total dose administered. These findings are quite similar to those observed in adults and indicate that the larger doses of digoxin required for digitalization in infants are not accompanied by increased metabolism or excretion but by increased blood levels and presumably increased tissue concentrations of the glycoside.
Correlation of Electrocardiographic Studies and Arteriographic Findings with Angina Pectoris
Authors: FRIESINGER GOTTLIEB C. , SMITH RAPHAEL F.
Published: June 2012

The relationships among angina pectoris, stress tests, and arteriography are complex. The majority of patients with angina pectoris can be adequately diagnosed by a careful history. Considerable attention to detail and repeated questioning is often necessary before the pain syndrome can be accurately classified. The resting electrocardiogram is of limited value in the diagnosis despite the fact that there is a high positive correlation between abnormal ST-T changes on the electrogram and significant obstructive lesions on coronary arteriograms. The value of the electrocardiogram is enhanced, and its specifiicity and sensitivity increased, when used in combination with exercise stress. The lowest error percentage is achieved by utilizing rate-standardized exercise tests and multiple leads with loads that produce heart rate responses of 80-90% of the expected maximum. Coronary arteriography gives the most specific anatomic information in patients with ischemic cardiac pain but will not directly disclose the cause of the pain. This fact assumes considerable importance when the pain has atypical features or when the patient is in the age group that has a high prevalence of coronary atherosclerosis. Similarly, the presence of past myocardial infarction is likely to be associated with obstructive disease, regardless of the cause of the patient's current symptoms. The exact role of lipid and other metabolic abnormalities in producing coronary arteriographic changes in the absence of symptoms needs further clarification, although the available data suggest that marked elevations in lipid fractions are frequently associated with atherosclerotic change, regardless of symptoms. Finally, the data imply that the anatomic abnormalities and functional consequences of the coronary atherosclerotic process are more important predictors of the patient's course than any specific symptomatic expression such as angina pectoris.
Determination of Systemic Vascular Resistance by a Noninvasive Technic
Authors: STEFADOUROS MILTIADIS A. , DOUGHERTY MICHAEL J. , GROSSMAN WILLIAM , CRAIGE ERNEST
Published: June 2012

Measurement of systemic vascular resistance in man currently requires arterial and venous cannulation, so that cardiac output and mean arterial blood pressure may be simultaneously determined. This report describes a noninvasive technic for determining systemic vascular resistance (SVR
n
), utilizing an ultrasonic method for cardiac output measurement, and a combination of sphygmomanometry and external carotid pulse tracing analysis for determination of mean arterial blood pressure. SVR
n
was measured by this technic in 18 patients and compared with systemic vascular resistance determined by conventional methods at cardiac catheterization (SVR
c
). There was excellent correlation, with SVR
c
= 0.865 SVR
n
+216 and r = 0.85. The sensitivity of the method was verified in studies on 12 normal subjects in whom SVR
n
while supine (1235 ± 61 dyne-sec-cm
–5
, mean ±
se
) was less than SVR
n
while standing (1416 ± 81,
P
< 0.01) and greater than SVR
n
supine after amyl nitrite inhalation (652 ± 41,
P
< 0.0001).

It is concluded that this noninvasive, simple, and safe technic should prove to be a useful bedside method for routine clinical measurement of systemic vascular resistance.
Roentgenographic Identification of Starr-Edwards Prostheses
Authors: BONCHEK LAWRENCE I. , DOBBS JERI L. , MATAR ADEL F. , CHAPPEL PHILIP , STARR ALBERT
Published: June 2012

Since 1960, more than 100,000 Starr-Edwards prostheses have been inserted. In conjunction with a continuing program of bioengineering improvements which has alleviated many problems, certain complications have been associated with specific valve models. Thus, it is often useful to identify the valve model in the absence of a previous operative record. The various models of Starr-Edwards prostheses can be differentiated from plain chest roentgenograms. The identifying roentgenographic characteristics are described in this report.
Ultrastructure of the Atrial, Ventricular, and Purkinje Cell, with Special Reference to the Genesis of Arrhythmias
Authors: LEGATO MARIANNE J.
Published: June 2012

An examination of the anatomy of the atrial, ventricular, and Purkinje cells reveals that the internal composition of all cardiac myofibers is qualitatively the same: all have a single nucleus, sarcomeric and mitochondrial units, and a well-developed sarcoplasmic reticulum. There are important differences, however, in the extent and distribution of the cell membrane and its derivatives in the myofiber. The presence or absence of a transverse tubular system and the variation in the number and type of intercellular linkages explain at least some of the characteristic electrical and functional properties of individual types of cells. The overall pattern of cellular organization in working atrial, ventricular, and conducting tissue is reviewed, and possible anatomic bases for current theories of normal and abnormal impulse generation and conduction in the heart are discussed.
Hypertension in the Inner City
Authors: FINNERTY FRANK A. , SHAW LAWRENCE W. , HIMMELSBACH CLIFTON K.
Published: June 2012

Sixty-one percent (6480 of 10,564) of the subjects in three census tracts were screened simply and efficiently in supermarkets. The prevalence of hypertension in the subjects over 25 years of age was 24%. Fifty percent (457 of 953) found to be hypertensive on initial screening failed to keep their first verification appointment. The number was reduced to 279 (29%) by personal contact or home visits by one of the cardiovascular group. Subsequent experience demonstrated that dropouts could be reduced to under 5% by scheduling the verification visit 24-48 hours after initial screening. At the second verification visit there were originally 108 "no-shows" which could be reduced to 36 by personal contact. Because of a fall in diastolic blood pressure below 90 mm Hg during the two verification visits, 296 patients were excluded from the study. Of the 953 initially hypertensive subjects, 284 (30%) were available for study. These patients were randomized into three groups, a stepped-up care group (group A) and two usual medical care groups (groups B and C). Of the original 98 patients, 84% are currently being followed in group A, whereas only 33% in group B and 17% in group C are under medical care. The diastolic blood pressure has returned to normal in 70% in group A, in 10% in group B, and in 17% in group C.
Normal Blood Supply to the Human His Bundle and Proximal Bundle Branches
Authors: FRINK RICHARD J. , JAMES THOMAS N.
Published: June 2012

The three major coronary arteries of 10 normal human hearts were injected with differentially colored gelatin mass for histologic determination of the blood supply to the His bundle and proximal bundle branches. The His bundle was dually supplied by the A-V node artery and the first septal branch of the left anterior descending artery in nine hearts, but entirely by the A-V node artery in one. The proximal right bundle branch was supplied by both the A-V node artery and septal branch in five hearts, only the septal branch in four, and the A-V node artery alone in one. The anterior half of the left bundle branch was dually supplied by the A-V node artery and septal branch in four hearts, entirely by the septal branch in five, and the A-V node artery alone in one. The posterior half of the left bundle branch was supplied by the A-V node artery alone in five hearts, dually by the A-V node artery and septal branch in four, and by the septal branch alone in one. The blood supply to most of the human His bundle and its proximal branches is thus dual in origin, with anastomosis principally within the His bundle.
Premature Atrial Stimulation as a Key to the Understanding of Sinoatrial Conduction in Man
Authors: STRAUSS HAROLD C. , SAROFF ALAN L. , BIGGER J. T. , GIARDINA ELSA GRACE V.
Published: June 2012

Since recording potentials directly from the sinoatrial node (SAN) is not yet possible, the electrophysiologic evaluation of this structure in intact human subjects must be accomplished with indirect technics. Two technics have been used to study SAN function in man: premature atrial stimulation (PAS) and rapid atrial pacing. Recent discussions of data using these technics have emphasized their role in determining SAN automaticity, but their role in evaluating conduction from atrium to SAN or SAN to atrium has not been fully explored. Using the technic of PAS, we have studied five patients with sinus bradycardia and symptoms of dizziness or syncope. Our analysis of the results obtained from these studies discloses the unique ability of this technic to evaluate conduction into and out of the SAN. An atrial premature depolarization (APD) elicited late in atrial diastole is followed by a compensatory pause (nonreset of the SAN pacemaker). An APD elicited earlier in atrial diastole is followed by a pause that is less than compensatory (SAN reset). From these responses estimates of sinoatrial conduction time were made. In one patient reset was never seen, suggesting markedly prolonged sinoatrial conduction. With these results in mind, the literature was reviewed and an alternate interpretation posed for existing data. PAS is not only a means of determining SAN automaticity, but also a very useful means of unmasking sinoatrial conduction abnormalities.
Juxtaposition of the Atrial Appendages
Authors: CHARUZI YZHAR , SPANOS PANAYIOTIS K. , AMPLATZ KURT , EDWARDS JESSE E.
Published: June 2012

Juxtaposition of the atrial appendages refers to that condition in which both atrial appendages or one and part of the other lie beside each other and to one side of the great arterial vessels. The appendages lying to the left of the great vessels (left-sided juxtaposition) is considerably more common than the state in which the appendages lie to the right of the great vessels (right-sided juxtaposition) by a ratio of about 6:1. Among left-sided juxtaposition it is common that the right atrial appendage be bifid and that only its left unit be "juxtaposed." Such a state is termed "bifid atrial appendage with partial juxtaposition." Juxtaposition almost always is associated with significant congenital heart disease in which transposition of the great vessels is commonly a feature. Tricuspid atresia with transposition or complete transposition are the two conditions most commonly associated with juxtaposition. Recognition of juxtaposition as an entity may serve, under certain circumstances, as an aid in the evaluation of an angio-cardiogram.
Echocardiogram in Ebstein's Anomaly with Wolff-Parkinson-White Preexcitation Syndrome, Type B
Authors: TAJIK ABDUL J. , GAU GERALD T. , GIULIANI EMILIO R. , RITTER DONALD G. , SCHATTENBERG THOMAS T.
Published: June 2012

The echocardiographic features of Ebstein's anomaly include a large anterior chamber, paradoxic ventricular septal motion (type B), increased velocity and amplitude of anterior tricuspid leaflet (ATL) motion, and delayed closure of the ATL. This delayed closure has been thought to be secondary to right bundle-branch block (RBBB). We have studied two patients by simultaneous echocardiography and phonocardiography. The findings in both patients were similar. One patient had RBBB and therefore resembles the previously reported patients. However, the other patient had W-P-W preexcitation syndrome, type B, and is reported here in more detail. The ATL closure of this patient was markedly delayed in spite of right ventricular preexcitation. This finding gives further insight into the altered pathophysiology in Ebstein's anomaly and implies that the delayed ATL closure is probably not due to RBBB and may be a specific feature of this anomaly.
Baroreceptor Activity in Normotensive and Hypertensive Uremic Patients
Authors: LAZARUS J. M. , HAMPERS C. L. , LOWRIE E. G. , MERRILL J. P.
Published: June 2012

Baroreceptor activity and postural blood volume changes were evaluated in four normotensive and nine hypertensive uremic patients before and after bilateral nephrectomy. Baroreceptor activity, reflected by the slope of linear regression of R-R interval with drug-induced systolic blood pressure elevation, was significantly lower in hypertensive than in normotensive patients. Six of nine patients had normal blood pressure following bilateral nephrectomy; however, the mean slopes of all nine patients, irrespective of postnephrectomy blood pressure, approached that of normotensive uremic patients. The slopes of both normotensive and hypertensive patients, before and after bilateral nephrectomy, were significantly less than normal controls. Similar results were found in lowering blood pressure with amyl nitrite.

Depressed baroreceptor activity is suggested to be secondary to neuropathy of the autonomic nervous system, chronic hypertension, heart disease, and anemia. It is speculated that this reduced baroreceptor sensitivity may accentuate the postural symptoms primarly induced by volume reduction on hemodialysis. There is no evidence in this study that depressed baroreceptor activity, as opposed to a reset baroreceptor, is a cause of hypertension in patients with chronic renal failure.
Mechanics of Left Ventricular Contraction in Chronic Severe Mitral Regurgitation
Authors: ECKBERG DWAIN L. , GAULT JAMES H. , BOUCHARD RICHARD L. , KARLINER JOEL S. , ROSS JOHN
Published: June 2012

The mechanics of left ventricular contraction were studied during diagnostic cardiac catheterization using high-speed cineangiography in 11 patients with severe chronic mitral regurgitation. Compared with a group of previously studied normal subjects, most of the patients with mitral regurgitation demonstrated a reduced velocity of shortening (V
cf
) during ejection at maximum wall stress, average = 1.01 circumferences/sec (circ/sec) (range 0.64-1.47 circ/sec). Maximum and mean V
cf
values also were reduced in these patients, averaging 1.40 and 0.94 circ/sec, respectively. These findings are in contrast to those in acute experimental mitral regurgitation, and to observations of normal shortening velocities in chronic experimental volume overloading, in which left ventricular contraction velocity is augmented. Compared with normal subjects, patients with mitral regurgitation had significantly larger left ventricular end-diastolic circumferences and volumes, and higher total left ventricular stroke volumes. The mean regurgitant volume was 41% of the total stroke volume, of which an average of 46% was ejected into the left atrium prior to aortic valve opening. The ejection fraction and extent of fiber shortening were normal in all but two patients despite depressed shortening velocities in most. It is concluded that analysis of velocity in the ejecting phase of left ventricular contraction is useful in detecting apparent alterations in inotropic state in the face of the altered loading conditions accompanying chronic mitral regurgitation. Further, favorable unloading conditions early during systole in patients with mitral regurgitation appear to mask the effects of a depressed inotropic state on the pumping function of the heart.
In Vivo
and Post Mortem Dissolution Rates of Pulmonary Emboli and Venous Thrombi in the Dog
Authors: MOSER KENNETH M. , GUISAN MICHEL , BARTIMMO ERNEST E. , LONGO ANTONIO M. , HARSANYI PAUL G. , CHIORAZZI NICHOLAS
Published: June 2012

Post mortem and
in vivo
dissolution rates of freshly induced venous thromboemboli were determined in 87 dogs. In 63, fresh thrombi formed in the inferior vena cava (IVC) were embolized to the lungs. Dissolution rates were determined by comparing the embolic volume recovered at autopsy with the volume of a second (control) thrombus formed in the IVC. Embolic volume recovered at 3 hr post mortem averaged 50.2% of control. In dogs maintained alive, embolic volume fell to 48.4% of control at 3 hr. With concomitant heparinization, only 34% of control embolic volume remained at 3 hr. In 24 dogs, thrombi were formed in the jugular veins. No dissolution of these thrombi occurred up to 6 hr post mortem. When they were exposed to circulating blood
in vivo
, only 67.2% of control volume was recovered at 3 hr. The rapid reduction of thromboembolic volume observed appears to be due to thrombolysis via the fibrinolytic system. The prompt and substantial post mortem and
in vivo
reduction of embolic volume should be considered in studies dealing with the cardiopulmonary responses following embolism in experimental animals, and perhaps, in man.
Coronary Heart Disease Epidemiology Revisited
Authors: EPSTEIN FREDERICK H.
Published: June 2012

Epidemiological research relating coronary heart disease risk to risk factors has been reviewed and condensed into simple, diagrammatic form. The predictive power of risk factors for detecting susceptibles in the population is presented. While much is now known about long-term prediction, there is an urgent need for tests to signal impending heart attacks. Against this background, the potential for preventive action is discussed in the light of current knowledge. The "clinical-individual" and "community" approaches to prevention are contrasted. To what extent is prevention on the community level warranted, pending the results of controlled prophylactic trials? The view is presented that advice on preventive measures to the population at large is justified at this time, based on education and planned change but short of an all-out campaign which must await conclusive data from intervention studies.
Papilloma of Cusp of the Aortic Valve
Authors: BUTTERWORTH J. SCOTT , POINDEXTER CHARLES A.
Published: June 2012

This is a case report of sudden death in a 50 year old man with a history of recent onset of atypical anginal pain. Death appears to have been caused by a small papilloma attached by a pedicle to the edge of the right cusp of the aortic valve. This papilloma occluded the right coronary ostium in a heart with a predominant right coronary circulation.
Tachycardia-Dependent Left Bundle Branch Block Associated with Bradycardia-Dependent Variable Left Bundle Branch Block
Authors: BAROLD S. SERGE , SCHAMROTH LEO
Published: June 2012

This report describes tachycardia- and bradycardia-dependent left bundle branch block in a patient who exhibited normal intraventricular conduction with impulses intermediate in timing. During bradycardia, longer cycles were associated with increasing degrees of incomplete left bundle branch block. These clinical observations support the existence of slow Phase 4 depolarization of latent pacemaker cells as one of the mechanisms for abnormalities of conduction.
Wenckebach Periods of Alternate Beats
Authors: HALPERN M. SUSANA , NAU GERARDO J. , LEVI RAÚL J. , ELIZARI MARCELO V. , ROSENBAUM MAURICIO B.
Published: June 2012

Wenckebach periods of alternate beats (AW) can be described as a 2:1 atrioventricular (A-V) block in which the conducted P waves show progressive prolongation of the P-R interval of the Wenckebach type. However, while classical Wenckebach periods terminate with a single blocked P wave, AW necessarily ends with (or begins from) two consecutive blocked P waves. Five clinical cases and several experimental examples of AW are reported. Recovery curves of A-V conduction were constructed, and it was demonstrated that AW is related to a marked prolongation of both the absolute and relative refractory periods. All the cases were associated with intraventricular block. In addition, recording of His bundle potentials in one case, histological study of the conduction system in another, and the experimental observations, support the view that AW tends to occur below the A-V node, in one of the main ventricular conducting fascicles. Four of the five patients developed complete heart block and Adams-Stokes seizures.
A New Technique for the Study of Left Ventricular Pressure-Volume Relations in Man
Authors: McLAURIN LAMBERT P. , GROSSMAN WILLIAM , STEFADOUROS MILTIADIS A. , ROLETT ELLIS L. , YOUNG DANIEL T.
Published: June 2012

Study of left ventricular pressure-volume relations in man has been limited by technical problems associated with left ventricular angiography. A new approach to this problem using simultaneous recording of left ventricular pressure and left ventricular volume (determined by echocardiography) was applied in 21 patients. Pressure-volume plots, constructed from pressure and volume values sampled at 20 or 40 msec intervals, had characteristic shapes for the states studied: normal, pressure overload, volume overload, and myocardial disease. These curves closely resembled pressure-volume plots previously determined by others from quantitative angiography.

The area inscribed by these plots was integrated to calculate left ventricular stroke work. Left ventricular stroke work index (gram-meters/m
2
) was in the range previously reported for the various states; normal-41 ± 12, pressure overload-102 ± 14, volume overload-136 ± 36, myocardial disease-65 ± 19. Inspection of the pressure-volume plots allowed assessment of valvular regurgitation by the characteristic deformation of the loop during "isovolumic" contraction and relaxation. Study of diastolic filling allowed qualitative assessment of left ventricular compliance. Patients with pressure overload had stiffer ventricles, with high diastolic pressure at lower volume, than normal or volume overload patients.

In summary, a new method is described for the beat-to-beat analysis of left ventricular pressure-volume relations in man.
Abnormal Motion of the Interventricular Septum in Right Ventricular Volume Overload
Authors: KERBER RICHARD E. , DIPPEL WILLIAM F. , ABBOUD FRANCOIS M.
Published: June 2012

Abnormal systolic motion of the interventricular septum has previously been noted using echocardiography in patients with atrial septal defect and has been ascribed to right ventricular volume overload. To evaluate the mechanism responsible for this abnormality, right ventricular volume overload was created in open-chest dogs by pumping blood from the left atrium to the right atrium. In seven of eight dogs changes in interventricular septum motion were produced acutely at shunt flow as low as 500 cc/min. When the shunt was decreased or stopped, interventricular septum motion returned to normal. Shunts producing left ventricular volume overload (aorta to left atrium and right atrium to left atrium) caused no change in interventricular septum motion. Clinical observations showed that six of seven patients with partial anomalous pulmonary venous connection and no atrial septal defect displayed abnormal interventricular septum motion on echocardiography. Twenty-one patients undergoing surgery for atrial septal defect were studied before and after operation. Sixteen of the 21 had abnormal interventricular septum motion preoperatively; the abnormal interventricular septum motion returned to normal in only one of the 16 patients during a postoperative follow-up period of up to one year. Three patients were studied only postoperatively up to six years after closure of atrial septal defect; all three retained abnormal interventricular septum motion.

Since the abnornal motion of the interventricular septum seen in patients with atrial septal defect can be produced and reversed acutely by creating a left-to-right atrial shunt in an experimental model, this abnormality must indeed be related to right ventricular volume overload. However, failure of interventricular septum motion to revert to normal following surgical correction in patients with atrial septal defect suggests that additional factors are involved in the persistence of this abnormal motion.
Complications of Coronary Bypass Surgery
Authors: BOLOOKI HOOSHANG , SOMMER LEONARD S. , GHAHRAMANI ALI , CUNHA DAMAIO , Gill Michael
Published: June 2012

In the past three years, among 170 patients undergoing aortocoronary bypass surgery, 11 (6%) developed acute myocardial infarction within 24 hours after surgery. An additional four patients (2%) developed myocardial infarction within three months after discharge. Clinically, acute myocardial infarction was suspected because of sudden, transient hypotension associated with dysrhythmia, angina, or cardiac arrest which responded to conventional therapy. Elevation of serum enzymes with acute ECG changes was also observed. Three of the 15 patients developing myocardial infarction died. In 12 patients cardiac catheterization studies were performed within two to ten weeks after the incident. Eleven of the 20 grafts were found occluded, and progression of coronary occlusive disease was seen in five. There was a marked decrease in left ventricular function, contractility, and compliance in all patients with left ventricular aneurysm formation or dyskinesia. Eight of these patients were asymptomatic. The results indicate that after coronary surgery a combination of sudden arrhythmia and transient hypotension is diagnostic of graft closure or development of acute myocardial infarction. Also, in spite of depressed cardiac function, most surviving patients remain angina free.
Functional Evaluation of Coronary Bypass Surgery by Exercise Testing and Oxygen Consumption
Authors: GUINEY TIMOTHY E. , RUBENSTEIN JOEL J. , SANDERS CHARLES A. , MUNDTH ELDRED D.
Published: June 2012

The short-term effects of coronary bypass surgery were evaluated in 40 male anginal patients with 100% follow-up. Bicycle ergometry was performed pre- and postoperatively (three to eight months). The rate-pressure product (RPP) at angina and 1.0 mm ST segment change was recorded as well as oxygen consumption at the end of each three-minute work load.

All but three survivors (92%) reported symptomatic improvement. Mortality was 5% (2/40). Among survivors morbidity included 29% (11/38) with apparent intra- or perioperative infarctions (new Q waves).

In 20 postoperative patients (50%) neither angina nor ST changes could be elicited when exercised to fatigue. RPP at fatigue was increased an average of 48%. The highest measured oxygen consumption increased an average of 61%. Ten patients (25%) developed angina or ST changes at a higher RPP. O
2
consumption in this group was unchanged (–3%). Five patients (12.5%) had no change or lower RPP at angina or ischemia. Their oxygen consumption was uniformly worse. Three patients (7.5%) were unable to exercise to preoperative RPP levels and could not be assessed. While the majority of revascularized patients are improved, the disparity between symptomatic and functional improvement reinforces the need for objective testing to determine the true effects of bypass surgery.
Internal Mammary Artery Grafts Without Optical Assistance
Authors: LOOP FLOYD D. , SPAMPINATO NICK , SIEGEL WAYNE , EFFLER DONALD B.
Published: June 2012

Internal mammary artery (IMA) grafts were performed without optical assistance in 175 consecutive patients during a 17-month period. The predominant indications were angina pectoris and the angiographic evidence of a 70% or greater obstruction in one or more major coronary arteries. Eight patients were considered to be in New York Heart Association functional class I, 63 class II, 71 class III, and 33 class IV before the operation. Forty per cent had three major vessels obstructed, and 33% had double vessel disease. IMA grafts were constructed to the anterior descending artery in 151 patients, diagonal branch in 22, and circumflex in two. Two of the 175 and three additional patients had free IMA grafts in the aortocoronary position. Saphenous vein grafts were combined with IMA grafts in 61%. One hospital death occurred, a 0.6% operative mortality.

Late clinical results were analyzed in the first 100 patients. Eighty-four of 99 have had complete remission of angina, and 12 are improved. Repeat arteriograms in 65 patients show 65 of 67 IMA grafts open (97%) and 56 (85%) of 66 saphenous vein grafts patent after an average interval of four months.

These early clinical and angiographic results are encouraging and indicate that the higher IMA patency may result from less size discrepancy between the graft and the coronary artery. The addition of the technically more complicated IMA graft to direct revascularization does not increase morbidity or mortality.
Emergency Coronary Artery Bypass Grafts in the Treatment of Myocardial Infarction
Authors: REUL GEORGE J. , MORRIS GEORGE C. , HOWELL JIMMY F. , CRAWFORD E. STANLEY , STELTER WOLF J.
Published: June 2012

Of the more than 1,900 patients undergoing coronary artery bypass procedures for coronary artery disease, a selected group of 17 patients underwent emergency coronary artery bypass because of the tentative diagnosis of acute myocardial infarction. Almost all patients had status angina prior to cardiac catheterization as was proven by electrocardiographic evidence and serum enzyme changes. When further verification was obtained by gross examination at surgery and autopsy in the patients who expired, most patients had severe end stage coronary artery disease manifested by functional classification and severe anatomical lesions. Cardiac catheterization was done in all patients prior to myocardial infarction. Because of the combination of pre-existing severe anatomical disease and status angina, coronary artery bypass surgery was done despite the presence of acute myocardial infarction in the three groups of patients. Group I consisted of patients with myocardial infarction without hypotension but persistent chest pain and clinical symptoms. Group II patients had similar findings plus hypotension. Group III patients experienced actual cardiac arrest and were resuscitated by portable femoral arteriovenous cardiopulmonary bypass. In group I three of eight patients died, in group II one of six patients, and in group III two of three patients. There were two late deaths at two and three months postoperatively. Operation in the face of acute myocardial infarction has been successfully employed in a selected group of patients.
Evaluation of Anticoagulant Therapy in Cloth-Covered Prosthetic Valves
Authors: ISOM O. WAYNE , WILLIAMS C. DAVID , FALK EMILY A. , SPENCER FRANK C. , GLASSMAN EPHRAIM
Published: June 2012

Over a period of four years, a series of 303 patients had prosthetic valve replacement with the Starr-Edwards cloth-covered metallic ball prosthesis. There were 135 aortic replacements, 105 mitral, 42 combined mitral and aortic, and 21 combined mitral and tricuspid. The frequency of thromboembolism and hemorrhage was studied in patients receiving warfarin sodium (Coumadin) and in those not receiving warfarin.

No thromboemboli occurred during 2,052 patient-months of observation in patients with aortic prostheses who were receiving warfarin, but 10 episodes of hemorrhage occurred. By comparison, after anticoagulants were discontinued, there was 1 episode of thromboembolism during 786 months of patient observation.

Among patients with mitral prostheses who were receiving warfarin, 3 episodes of thromboembolism occurred in 2,081 patient-months of observation, during which 5 hemorrhagic episodes also occurred. By comparison, after warfarin was discontinued, there were 3 episodes of thromboembolism during 402 months.

In patients with mitral and aortic prostheses who were receiving warfarin, 1 episode of thromboembolism occurred in 670 patient-months, and no episodes of hemorrhage. Without anticoagulation, 2 episodes of thromboembolism occurred in 130 patient-months.

In patients with mitral and tricuspid prostheses who were receiving warfarin, there were no episodes of thromboembolism during 186 patient-months, but there was 1 episode of hemorrhage. Without anticoagulation, however, there were 3 episodes of thromboembolism during 32 months of patient observation.
Ejection Time by Ear Densitogram and Its Derivative
Authors: QUARRY-PIGOTT VERONICA , CHIRIFE RAUL , SPODICK DAVID H.
Published: June 2012

Ear densitographic ejection times (EDET) and first derivative ear densitogram ejection times (dEDET) were studied to determine whether their reliability and validity justify their substitution for ejection times derived from the far less stable carotid pulse tracing. Inter- and intra-subject comparisons were made on thirty individuals under a wide variety of disease and challenge states. Statistical analysis of the data-which had been obtained through a blinded procedure-showed an overall correlation (
r
) of .98 for carotid vs EDET and .99 for carotid vs dEDET. The
t
-test demonstrated no significant differences among ejection times derived from the three methods. Moreover, the close tracking at rest and during challenges of ejection times derived from these curves with those from the carotid indicate that either method may be substituted for standard carotid curves without sacrificing reliability or validity of the measure. Both ear curves offer distinct advantages over carotid pulse curves because their sensor is self-retaining and they remain stable during exercise and other body and respiratory movements. The additional feature of simplicity in reading the first derivative of the ear densitogram over its undifferentiated curve makes dEDET the preferred method.
Aortic Dysplasia in Infancy Simulating Anomalous Origin of the Left Coronary Artery
Authors: PRICE ALBERT C. , LEE DIXON A. , KAGAN KATHLEEN E. , BAKER WILLIAM P.
Published: June 2012

A case is reported of an infant believed to have had anomalous origin of the left coronary artery. Clinical evaluation and angiography appeared to support the diagnosis. At necropsy, however, the left coronary was seen to arise from the aorta but was totally occluded by dysplastic changes which resulted in myocardial infarction and death of the patient. There was minimal aortic deformity produced by these changes, and no aortic gradient was present. Thus, this very rare case of minimal supravalvular aortic stenosis with left coronary artery occlusion was not recognizable clinically nor angiographically.
Transient Wolff-Parkinson-White Syndrome and Neonatal Reciprocating Tachycardia
Authors: MOENE RUDOLF J. , ROOS JAN P.
Published: June 2012

A premature infant is reported with a transient Wolff-Parkinson-White (WPW) Syndrome, atrial reciprocating rhythm and atrial reciprocating tachycardia during the second month of life. The spontaneous onset and termination of numerous attacks of tachycardia were recorded and analyzed. Many electrocardiographic tracings suggested the presence of Wenckebach periodicity of the anomalous A-V pathway resulting in atrial reciprocal rhythm which from time to time initiated a reciprocating tachycardia. In some tracings atrial reciprocal rhythm was preceded by a wandering atrial pacemaker. The presented electrocardiographic tracings emphasize the significance of reciprocal rhythm in the genesis of paroxysmal tachycardia in infants with a transient WPW Syndrome. At the end of the second month of life the attacks of tachycardia stopped, and the electrocardiogram became normal and remained so during a total follow-up period of ten months.
Relationship Between the ECG, Ventricular Activation, and the Ventricular Conduction System in Ostium Primum ASD
Authors: BOINEAU JOHN P. , MOORE E. NEIL , PATTERSON DONALD F.
Published: June 2012

A combined electrophysiologic-anatomic study was performed in a dog with a congenital atrial septal defect (ASD) primum. Comparisons were made between the dog and electrophysiologic data obtained in four patients with ASD primum. The ECGs and VCGs in both the dog and patients revealed the characteristic features of superior orientation, counterclockwise rotation, and slow-rightward terminal forces in the frontal plane QRS. In both the dog and the patients, epicardial ventricular activation revealed early posterior LV wall excitation and later anterior left ventricular (LV) depolarization. Also, there was a marked delay in the activation of the RV in both dog and patients. In the dog, Purkinje (Pj) potentials were recorded from the endocardium of the anterior and posterior LV wall and the anterior RV wall. The endocardial-Pj activation times of these three regions were correlated with the measured lengths of the three major divisions of the conduction system supplying them. Premature activation of the posterior LV Pj and delayed activation of the anterior LV and RV Pj was observed. The marked asynchrony of Pj activation was due to a developmental asymmetry of the ventricular conduction system, characterized by markedly different lengths of the three major divisions. Purkinje conduction velocity was 1.5 m/sec, and there were no areas of block or slow conduction. The agreement between the dog and human data indicated an identical mechanism for patients with ASD primum. The terms left anterior-superior hemiblock and right bundle branch block are inappropriate descriptions of this lesion.