bluuebunny/crossref_metadata_2025 huggingface dataset:
Potassium-43 Myocardial Perfusion Scanning for the Noninvasive Evaluation of Patients with False-Positive Exercise Tests
Authors: ZARET BARRY L. , STENSON ROBERT E. , MARTIN NEIL D. , STRAUSS H. WILLIAM , WELLS HARRY P. , MCGOWAN RONALD L. , FLAMM M. D.
Published: June 2012

Twelve patients with false-positive ECG exercise tests presented with ischemic ECG responses (greater than one mm ST segment depression) during graded maximal treadmill exercise testing in the absence of exercise-induced chest pain or clinical coronary heart disease. Coronary arteriography, left ventriculography and hemodynamic evaluation revealed no significant abnormality in these patients. Transmyocardial lactate analysis during atrial pacing revealed a normal extraction (mean 21%) during pacing stress in five patients.

Nine of 12 patients were evaluated with exercise potassium-43 myocardial perfusion imaging whereby the radioactive tracer was administered intravenously during exercise at a time when abnormal ECG changes were present. Myocardial images in these nine patients all showed a normal homogeneous pattern of radioisotope distribution. These results are in direct contrast to findings in patients with coronary heart disease in whom reproducibly demonstrable abnormal regions of decreased potassium-43 accumulation have been noted in myocardial images obtained following injection of the radioactive tracer during exercise. Potassium-43 exercise myocardial perfusion scanning thus appears to be an accurate noninvasive method of assessing patients with suspected false-positive exercise tests and provides a means of increasing the specificity of exercise testing.
Simple Quantitative Vectorcardiographic Criteria for the Diagnosis of Right Ventricular Hypertrophy
Authors: CHOU TE-CHUAN , MASANGKAY MANUEL P. , YOUNG RAYMOND , CONWAY GENE F. , HELM ROBERT A.
Published: June 2012

The vectorcardiogram is a useful supplement to the conventional electrocardiogram in the recognition of right ventricular hypertrophy. Many quantitative criteria have been proposed. However they are often too complicated for routine clinical application. Based on the distribution of the QRS loop area in the various quadrants in the vectorcardiogram in 198 normal subjects, three simple criteria for diagnosis of right ventricular hypertrophy are derived: 1) the anterior and rightward QRS loop area in the transverse plane is greater than 70% of the total; 2) the QRS loop area in the right posterior quadrant of the transverse plane is greater than 20% of the total; 3) the QRS loop area in the right inferior quadrant in the frontal plane is greater than 20% of the total. Vectorcardiogram recordings in 97 patients with atrial septal defect, mitral stenosis, and chronic obstructive lung disease with pulmonary hypertension met one or more of the criteria in 80 (83%). The conventional electrocardiogram of these patients was suggestive of right ventricular hypertrophy in 64 (66%). It is concluded that the proposed vectorcardiographic criteria provide a sensitive means for the diagnosis of right ventricular hypertrophy. Their specificity however was not tested.
Left Atrial Size and Atrial Fibrillation in Mitral Stenosis
Authors: PROBST PETER , GOLDSCHLAGER NORA , SELZER ARTHUR
Published: June 2012

In a series of 135 patients with mitral valvular stenosis, three groups were identified: those in sinus rhythm, those with intermittent atrial fibrillation, and those with longstanding, established atrial fibrillation. Examination of the relationships between atrial fibrillation, hemodynamic findings and radiologic data in mitral stenosis was undertaken. Analysis of clinical and hemodynamic factors in the three groups revealed that: 1) age is an etiological factor in the production of atrial fibrillation, as suggested by the age distribution among the three groups; 2) left atrial enlargement may be the result, rather than the cause, of atrial fibrillation; and 3) severity of mitral stenosis is not invariably related to the incidence of atrial fibrillation. Hemodynamic measurements were not significantly different among the three groups, with the single exception of lower cardiac outputs found in patients with established atrial fibrillation. Since no single consequence of mitral stenosis always produces atrial fibrillation, it is suggested that several factors in different combinations can initiate the self-perpetuating process of atrial fibrillation and that the classic form of the arrhythmia may lead secondarily to left atrial enlargement.
Hemodynamics in Ruptured Chordae Tendineae and Chronic Rheumatic Mitral Regurgitation
Authors: BAXLEY WILLIAM A. , KENNEDY J. WARD , FEILD BOLLING , DODGE HAROLD T.
Published: June 2012

Twenty-five patients with proven ruptured mitral chordae tendineae and 25 patients with chronic rheumatic mitral regurgitation were studied with quantitative biplane left-heart angiocardiography. Compared to the rheumatic patients, the ruptured chordae group had strikingly smaller left atrial maximum volume (mean: 119 ± 47 vs 267 ± 131 ml/m
2
mean) and less compliant left atrium (mean: 1.61 ± 1.52 vs 5.14 ± 4.31 ml/mm Hg-m
2
); less impressively but significantly smaller left ventricular end-diastolic volume (mean: 142 ± 43 vs 188 ± 75 ml/m
2
) and mass (mean: 133 ± 27 vs 166 ± 50 mm/m
2
), and relatively insignificant tendency toward smaller left ventricular stroke volume and regurgitant flow per stroke. Ejection fractions, ventricular pressures, and forward flow per stroke were not significantly different. Within the ruptured chordae group, the duration of heart failure was not significantly correlated with any hemodynamic variable. These results indicate quantitatively the spectrum of abnormal hemodynamics in these two different etiologic forms of mitral insufficiency. The most striking differences between the two groups are in atrial dynamics. In spite of the usually more acute nature of ruptured chordae, significant compensatory dilatation and hypertrophy of the left ventricle is common in those patients. In both groups, large regurgitant flows with relatively normal ventricular function as expressed by ejection fraction is the usual finding.
Impedance Phlebography
Authors: SCHULMAN ROBERT HARRIS , FRIEDMAN SANDOR A. , DEGENSHEIN GEORGE
Published: June 2012

Impedance phlebography, a noninvasive approach to the diagnosis of venous thrombosis, depends on decreasing calf electrical impedance in normal subjects during inspiration. In order to assess the relationship between impedance changes and inspiratory volume, normal subjects were studied at various depths of inspiration. The mean inspiration volume required for a result indicating no evidence of venous thrombosis was over 1500 ml. There was significant variation between subjects and between limbs in the same subject. Routine postoperative patients were not generally able to achieve these inspiration volumes. It is concluded that insufficient tidal volume is responsible for many false positive results. Impedance phlebography is not reliable without simultaneous spirometric evidence of high inspiratory volume.
Hyper-Low Density Lipoproteinemia in United States Air Force Recruits
Authors: KOCHER DAVID B. , MAZZAFERRI ERNEST L. , KUDZMA DAVID J. , STOLL RAYMOND E.
Published: June 2012

Six hundred and three selected, lean, healthy United States Air Force recruits, ranging from age 18 to 22, were screened for hyperlipoproteinemia shortly after military induction. There were 307 men and 296 women. Mean plasma lipid levels were lower than generally observed in the population at large: cholesterol = 139 ± 39 (
sd
) mg%; low density lipoprotein (LDL) cholesterol = 86 ± 40 mg%; high density lipoprotein (HDL) cholesterol = 59 ± 23 mg%; total plasma triglyceride (TG) = 40 ± 17 mg%. The low total plasma cholesterol was largely attributed to the LDL cholesterol fraction. White women had lower total and LDL cholesterol levels (
P
< 0.01) than men, but no other significant sex or race differences were observed. Twenty-six individuals (4.3%) had values for either one or both total plasma cholesterol and LDL cholesterol concentrations above the limits arbitrarily established for this group and are regarded as having hyper-low density lipoproteinemia. More individuals were identified as abnormal by a determination of total plasma and LDL cholesterol levels than by measuring total plasma cholesterol alone. No other lipoprotein abnormalities were observed. The lipid concentrations observed in these lean, healthy, young subjects are probably a reflection of ideal values around age 20.
Lung Water in Patients with Acute Myocardial Infarction
Authors: BIDDLE THEODORE L. , KHANNA PURSHOTTAM K. , YU PAUL N. , HODGES MORRISON , SHAH PRAVIN M.
Published: June 2012

Pulmonary extravascular water volume (PEV) or lung water was measured in 45 patients with acute myocardial infarction, utilizing the double radioisotope indicator dilution technique. A PEV greater than the upper limit or normal (120 ml/m
2
) was found in 27 patients, 23 of whom had an elevated pulmonary wedge or pulmonary artery diastolic pressure. A significant correlation was found between PEV and pulmonary wedge or pulmonary diastolic pressure in the whole series. A progressive increase in average PEV was observed from Class I (uncomplicated) to Class IV (shock) patients. There was also a progressive increase in PEV from patients with normal chest X-ray findings to those with radiologic evidence of acute pulmonary edema. In seven of 11 patients with initial elevation of both PEV and pulmonary wedge pressure, repeat determinations demonstrated a substantial reduction in both parameters over a period of 2-4 days.

We postulate that an increased PEV in patients with acute myocardial infarction is largely due to an elevated pulmonary capillary pressure. The latter is probably a consequence of an elevated left ventricular diastolic pressure, which may be a manifestation of either left ventricular failure or a decrease in left ventricular compliance.
Wall Thickness and Diastolic Properties of the Left Ventricle
Authors: GROSSMAN WILLIAM , MCLAURIN LAMBERT P. , MOOS SALLY P. , STEFADOUROS MILTIADIS , YOUNG DANIEL T.
Published: June 2012

Diastolic properties of the left ventricle (LV) are probably influenced by several factors, including completeness of ventricular relaxation, composition of the ventricular wall, and wall thickness. This study has utilized a combined ultrasonic and hemodynamic technique to examine the influence of LV posterior wall thickness at end diastole (h
p
) on LV diastolic characteristics in 24 patients with various forms of heart disease. The slope of late diastolic LV pressure-diameter relations (ΔP/ΔD) was calculated and used as a measure of effective diastolic stiffness (S) late in diastole. S was normalized for average LV pressure during the interval of measurement (P) as S/P, called S
N
. LV end diastolic pressure (LVEDP), volume index (LVEDVI), and mass index (LVMI) were measured in each patient during the same study at which h
p
, S and S
N
were determined.

The range of h
p
was 5.6 to 18.6 mm; it was highest in a patient with aortic stenosis, and lowest in those with mitral stenosis. Linear regression of h
p
against S, S
N
and LVEDP showed significant correlation, with
r
= 0.85, 0.75, and 0.74 respectively (
P
< 0.001 for each regression analysis). Poor correlation was noted with LVEDVI, ΔP, and ΔD. Of 12 patients with LV hypertrophy (LVH) by ECG, four had normal h
p
(7.9 ± 1.0 mm) and eight had abnormal h
p
(13 ± 0.6 mm). Those with normal h
p
had nearly normal values for S (3.5 ± 0.5 mm Hg/mm) while those with abnormal h
p
showed significant increases in S (7.7 ± 1.5 mm Hg/mm), indicating that LVH may alter S only insofar as there is an associated increase in h
p
. Consistent with this was the observation that within the group of patients having increased LVMI, LVMI itself was a poor predictor of S (
r
= 0.50, NS) while h
p
remained an excellent predictor of S (
r
= 0.86,
P
< 0.001). In summary, this study suggests that wall thickness is an important determinant of left ventricular diastolic stiffness and pressure, and that wall thickness appears to predict diastolic stiffness independent of the presence or absence of LVH or increased LV mass.
Chagasic Cardiopathy
Authors: COSSIO PATRICIO M. , DIEZ CARLOS , SZARFMAN ANA , KREUTZER EDUARDO , CANDIOLO BARTOLOMÉ , ARANA ROBERTO M.
Published: June 2012

Twenty-four out of 25 patients with Chagas' heart disease have circulating immunoglobulins which react by indirect immunofluorescence technique with endocardium, interstitium and blood vessels of the heart. With skeletal muscle the reaction was observed in interstitium and vascular structures, but with other organs it was limited to vascular structures. This endocardial-vascular-interstitial factor (EVI) fixed complement. Some evidence indicated that this reaction could be obtained using the serum and tissues from the same patient: for instance, in one positive case a right atrium biopsy was performed. When this substrate was used for indirect immunofluorescence, employing the patient's own serum, positive results were obtained. Specificity is not related to AB blood group systems, or to Forssman or Wassermann antigens. The reacting factor was effectively absorbed from sera with organ homogenates, and with guinea pig red blood cells although it was independent of heterophil antibodies. In almost all cases studied, the EVI factor of the serum, when absorbed with epimastigotes of
T. cruzi
, results in a negative reaction, suggesting that the genesis of the reacting gamma globulin is related to antigens of
T. cruzi.

The EVI factor was also observed in 19 of 47 asymptomatic controls from an endemic area with positive serology for
T. cruzi
and in 3 of 27 with negative serology. These 3 cases had anti-
T. cruzi
antibodies in titers just below those considered of clinical value. The EVI factor was not observed in 119 normal individuals and 286 patients with selected cardiovascular diseases or another pathology from a nonendemic area. These findings and those mentioned above were statistically significant (
P
< 0.001). These results indicate the possibility of a more accurate diagnosis of chagasic myocardiopathy based on the study of the EVI factor, because in an individual case the diagnosis of chronic chagasic cardiopathy can be considered with a low probability in the absence of this factor.
Incorporation of Radiolabelled Fibrinogen into Venous Thrombi Induced in Dogs
Authors: KRAVIS THOMAS C. , SHIBEL ELAINE M. , BROOKS JOHN D. , MOSER KENNETH M.
Published: June 2012

The time course and locus of radiolabelled fibrinogen (RLF) incorporation into venous thrombi were studied in dogs. Incorporation of radiolabelled fibrinogen (RLF) into fresh venous thrombi induced in vivo was studied by serial autoradiography, well-counting and surface counting. Autoradiographs disclosed diffuse incorporation of RLF into thrombi formed before and after RLF injection. Well-counting data also reflected thrombus RLF accumulation in both instances, although this accumulation was discernible earlier in thrombi induced in the presence of circulating RLF. Thrombi induced prior to RLF injection were detectable by surface counting after six hours. These studies support the potential value of RLF in detecting human venous thrombosis but also point out the limitations of the technique as well as questions which require clarification.
Patterns of Ventriculo-Atrial Conduction in the Wolff-Parkinson-White Syndrome
Authors: WELLENS HEIN J. , DURRER DIRK
Published: June 2012

In 36 patients with the Wolff-Parkinson-White syndrome, ventriculo-atrial (VA) conduction was studied using the single test stimulus method. In 22 patients no significant change in VA conduction time occurred following test stimuli with increasing prematurity suggesting exclusive VA conduction by way of the accessory pathway, an accessory pathway with a shorter refractory period than the His-AV node pathway, or identical refractory periods in both pathways. In 14 patients showing this VA conduction pattern tachycardias could be initiated by a single early ventricular premature beat. This finding lends credence to the hypothesis that the accessory pathway is an essential link in the tachycardia circuit. In two of the five patients showing exclusive VA conduction over the His-AV node pathway single re-entrant beats with antegrade conduction over the accessory pathway could be elicited by appropriately timed ventricular premature beats. In one patient showing this pattern a sustained tachycardia with AV conduction over the accessory pathway could be initiated. A total of eight patients did not show VA conduction over the accessory pathway.
A Balloon Tipped Catheter for Obtaining His Bundle Electrograms Without Fluoroscopy
Authors: MEISTER STEVEN G. , BANKA VIDYA S. , CHADDA KUL D. , HELFANT RICHARD H.
Published: June 2012

A technique for recording His bundle activity in man without fluoroscopic guidance is described. Balloon tipped tri- or tetrapolar catheters were designed with pacing electrodes located at the catheter tip, and two fine sensing electrodes 4 and 5 cm behind it. The catheter tip was preformed into a "J" curve. Following percutaneous transfemoral insertion, the catheter is floated to the right ventricle under electrocardiographic control. This tip configuration and the transfemoral route of insertion typically directs the catheter into an inverted "J" position with its tip in or near the right ventricular apex. Subsequent catheter withdrawal carries the sensing electrodes through the superior portion of the tricuspid valve and permits recording from the His bundle. With this technique His bundle recordings were possible in 23 of 24 patients. Re-advancement into the right ventricular apex permits stable temporary pacing.
James B. Herrick Award Acceptance
Authors: FRIEDLICH ALLAN L.
Published: June 2012

Dr. Allan L. Friedlich worked closely with Dr. White for many years at the Massachusetts General Hospital, in American Heart Association affairs and in international cardiological meetings. He was chosen by Dr. White as his personal deputy at several meetings of the International Society and International Federation of Cardiology, and accepted the James B. Herrick Award presented by the Council on Clinical Cardiology of the American Heart Association to Dr. White on November 8, 1973.
Echocardiographic Findings in Discrete Subvalvular Aortic Stenosis
Authors: POPP RICHARD L. , SILVERMAN JAMES F. , FRENCH JAMES W. , STINSON EDWARD B. , HARRISON DONALD C.
Published: June 2012

Echographic features of three patients with discrete subvalvular aortic stenosis are presented. These include a narrowed area of the left ventricular outflow tract just below the aortic valve cusps in all cases. A high-intensity but thin echo was seen in the high left ventricular outflow tract at the level of the mitral annulus in one patient with a subaortic diaphragm. In one of the three patients abnormality of aortic cusp motion was suggested as well.
The Comparative Antiarrhythmic Actions of Lidocaine and its Quarternary Derivative, Methyl Lidocaine
Authors: KNIFFEN FRANK J. , LOMAS TIMOTHY E. , NOBEL-ALLEN NANCY L. , LUCCHESI BENEDICT R.
Published: June 2012

Lidocaine has proved to be an effective antiarrhythmic agent in the management of ventricular arrhythmias subsequent to acute myocardial infarction. Lidocaine's short duration of action and its propensity for producing central nervous system (CNS) stimulation suggest that a safer and more effective therapeutic agent, based on a modification of the lidocaine structure, might be found. The quaternary ammonium compound, methyl lidocaine, was synthesized and its actions in experimentally-induced arrhythmias were studied and compared to those of lidocaine. The antiarrhythmic effects of lidocaine and methyl lidocaine were examined in the anesthetized dog against ouabain-induced ventricular tachycardia and in conscious animals with ventricular tachycardia 48 hours after two-stage ligation of the anterior descending coronary artery. Both pharmacological agents were capable of reversing digitalis-induced arrhythmias and restoring normal sinus rhythm in animals 48 hours after surgical ligation of the anterior descending coronary artery, but methyl lidocaine remained effective for a significantly longer period and its continual administration was not associated with signs of CNS toxicity. In experiments designed to determine the electrical fibrillation threshold, both drugs were able to reduce the vulnerability to ventricular fibrillation but the time course of action for each drug differed. Lidocaine had an immediate effect of increasing the ventricular fibrillation threshold whereas the peak effect of methyl lidocaine was delayed and the increase in the fibrillation threshold lasted longer. This study concludes that the quaternary derivative of lidocaine, methyl lidocaine, possesses antiarrhythmic properties similar to those of lidocaine, but differs in its duration of action and lack of overt stimulatory effects upon the central nervous system.
Left Ventricular Subendocardial Ischemia in Severe Valvar and Supravalvar Aortic Stenosis
Authors: VINCENT WILLIAM R. , BUCKBERG GERALD D. , HOFFMAN JULIEN I. E.
Published: June 2012

Severe valvar aortic stenosis (VAS) and supravalvar aortic stenosis (SVAS) each may cause left ventricular (LV) subendocardial ischemia and infarction, even with patent coronary arteries. LV ischemia in VAS has been related to reduced coronary perfusion relative to raised metabolic requirements, whereas this mechanism of ischemia has not been widely accepted in SVAS because coronary perfusion pressure is higher than normal.

LV subendocardial coronary blood flow (CBF) occurs predominantly in diastole and a diastolic pressure-time index (DPTI) was used to estimate it. LV oxygen requirements were estimated from the systolic pressure-time index (SPTI). The ratio DPTI:SPTI (supply:demand) was evaluated as an estimate of the adequacy of subendocardial flow. SVAS was produced acutely in nine dogs and phasic left CBF and distribution of CBF to the LV myocardium were measured. Although mean CBF always rose with aortic constriction, flow in diastole fell from a control of 80% to 34% (
P
< 0.001) and LV myocardial flow distribution became inhomogeneous with the proportion of flow to subendocardial muscle decreasing 63% (
P
< 0.001). Departure from the normal homogeneous flow distribution to the LV was predictable from the ratio DPTI:SPTI; values below 0.7 were always associated with relative subendocardial underperfusion.

DPTI:SPTI ratios in two patients, one with severe VAS (0.25) and one with SVAS (0.39) were well below values obtained in 18 control patients (1.03 ± 0.23), and were similar to the ratios in dogs with SVAS (0.27 ± 0.08). Both patients had ECG changes suggesting LV ischemia. The mechanism of subendocardial ischemia is thought to be the same in both types of stenosis and its presence is predictable from pressure measurements available at cardiac catheterization.
The Natural History of the So-Called Aneurysm of the Membranous Ventricular Septum in Childhood
Authors: FREEDOM ROBERT M. , WHITE ROBERT D. , PIERONI DANIEL R. , VARGHESE P. JACOB , KROVETZ L. JEROME , ROWE RICHARD D.
Published: June 2012

Fifty-six children with isolated membranous ventricular septal defect (VSD) included in the National Natural History Cooperative Study for Congenital Heart Disease were studied at the Johns Hopkins Hospital Center to determine the occurrence and natural history of an associated "aneurysm of the membranous septum" (AMS). These patients represented a wide range of ages and VSD size. Each child was evaluated by two cardiac catheterizations four years apart, with regular clinical examinations in the interval. The diagnosis of AMS was based on angiographic criteria, and as such may encompass several distinct anatomic lesions.

Twenty children had AMS at the first catheterization; all were over age two, and all but one had a pulmonic-to-systemic flow ratio (Qp/Qs) of less than 2.0, with normal intracardiac pressures. Four years later, repeat catheterization revealed only minor changes in Qp/Qs and angiographic appearance of the aneurysms in this group. Twelve new cases of AMS were also demonstrated at the second study; seven of these children underwent a significant diminution in Qp/Qs during the period in which the aneurysm was formed. No cases of spontaneous anatomic closure were observed in the course of our study, nor were there any serious complications which could be attributed to the presence of an aneurysm. Overall, AMS was found in 32 of 56 patients (57%), and in 31 of 44 (70%) of those with a Qp/Qs less than 2.0.

These findings suggest that AMS is common among children with small membranous VSD, and that its course in childhood is usually stable and asymptomatic. Although anatomic closure of the VSD was not observed during this four year study, our data support suggestions that aneurysm formation may play an important role in some cases of spontaneous diminution in the functional size of an associated membranous VSD.
The Postpericardiotomy Syndrome and Antiheart Antibodies
Authors: ENGLE MARY ALLEN , MCCABE JOHN C. , EBERT PAUL A. , ZABRISKIE JOHN
Published: June 2012

In a prospective, double-blind study, heart-reactive antibody in high titer was detected, using an indirect immunofluorescent technique, in the serum of patients in whom the postpericardiotomy syndrome developed after intrapericardial surgery. The syndrome occurred in 26 of 86 consecutive longterm survivors of such surgery, an incidence of 30%. Presence of antibody correlated closely with the clinical syndrome. Demonstration of this antiheart antibody in high titer appears to offer laboratory confirmation of the syndrome.
Transvenous, Transmediastinal, and Transthoracic Ventricular Pacing:
Authors: BRENNER ALAN S. , WAGNER GALEN S. , ANDERSON S. T. , ROSATI ROBERT A. , MORRIS JAMES J.
Published: June 2012

Two hundred and five patients who received a total of 247 electrode systems-129 transvenous, 68 transmediastinal and 50 transthoracic-are compared after complete uniform two-year follow-up. The transvenous patients had low hospital morbidity (19%) and short hospital stays (75% ≤ 8 days) but a high incidence of electrode failure by 24 months (38%). The transmediastinal and transthoracic patients had more hospital complications (35% and 34%) and longer periods of hospitalization (57% and 70% > 8 days) but fewer instances of failure by 24 months (16% and 11%). Most transvenous electrode failures were secondary to dislodgement. Transmediastinal right epicardial electrodes had the unique problem of threshold elevation and failure between six and 12 months after implantation as well as a high incidence of sudden death in this same period. Although the high incidence of endocardial electrode instability dictates the need for an alternative approach to permanent pacing, the failure of the transmediastinal approach to significantly alter postoperative morbidity (as compared with transthoracic electrodes) and the incidence of threshold elevation remote from right ventricular implantation suggest that limitation of thoracotomy (via the transmediastinal approach) should not take precedence over left ventricular implantation. Development of electrodes which would provide more permanent low resistance fixation to right ventricular endocardium or epicardium may be necessary before the transthoracic approach can be abandoned.
Paradoxical Motion of Interventricular Septum in Left Bundle Branch Block
Authors: ABBASI ABDUL S. , EBER LESLIE M. , MACALPIN REX N. , KATTUS ALBERT A.
Published: June 2012

Abnormal interventricular septal motion, with pre-ejection posterior motion and anterior motion away from the posterior left ventricular wall during ejection, was demonstrated by echocardiography in 14 out of 17 cases with complete left bundle branch block (LBBB). Two of 14 cases had intermittent LBBB and showed abnormal septal motion only during LBBB. Of the control group of 49 patients without LBBB but with cardiac disorders similar to the cases with LBBB, only two showed abnormal septal motion. However, pre-ejection motion was not seen in these two cases. During right ventricular pacing abnormal septal motion was observed in three out of ten cases. It is suggested that conduction abnormalities are responsible for abnormal septal motion in LBBB; normal septal motion in most cases with right ventricular pacing may be due to different conduction pathways not affecting the septum.
Echocardiographic Abnormalities in the Mitral Valve Prolapse Syndrome
Authors: POPP RICHARD L. , BROWN OWEN R. , SILVERMAN JAMES F. , HARRISON DONALD C.
Published: June 2012

Two echocardiographic patterns of the mitral valve have been found to correlate with anatomic and/or angiocardiographic appearance of redundancy of the mitral valve. The echocardiographic abnormality may be found in the presence or absence of auscultatory findings, while the apparent separation of the anterior and posterior mitral leaflets on echocardiogram does not seem to represent anatomic separation leading to mitral regurgitation. Since the echocardiographic abnormality is found in the absence of various parts of the syndrome, it may be used as a tool to diagnose the mitral valve prolapse syndrome, discover its incidence and follow its natural history.
Echocardiographic and Phonocardiographic Characteristics of the Lillehei-Kaster Mitral Valve Prosthesis
Authors: GIBSON THOMAS C. , STAREK PETER J. K. , MOOS SALLY , CRAIGE ERNEST
Published: June 2012

The Lillehei-Kaster (L-K) valve is a tilting disc prosthesis currently in use for heart valve replacement. We report data from phonocardiography (PHONO) and echocardiography (ECHO) in 20 patients with a normally functioning mitral valve prosthesis (MVP). The MVP is well recorded by ECHO, resembling a mitral stenosis pattern with a disc excursion of 7 to 12 mm and a mean opening and closing velocity of 37.7 and 59.8 cm/sec, respectively. Combined PHONO and ECHO show that the opening sound of the MVP is small, related to onset of valve opening and not peak opening. It follows the aortic component of the second sound (A
2
) by 0.05 to 0.09 sec in normals; it may be absent (12/20). Peak opening follows A
2
by 0.08 to 0.12 sec. The closing sound of the MVP, best heard in the mitral area, is always two-fold with a small initial high frequency (HF) component and a second large HF sound separated by no more than 0.03 sec. The first component (A) is related to onset of closure and the second (B) to completion of closure. Systolic and diastolic murmurs were commonly present. These data establish the normal ECHO and PHONO findings for patients with L-K MVP. Two other patients are also reported in whom such data were helpful for the noninvasive evaluation of valve function, indicating in one instance acute mitral regurgitation and in the other an increase in degree of aortic regurgitation.
Postinfarction Ventricular Septal Rupture
Authors: GIULIANI EMILIO R. , DANIELSON GORDON K. , PLUTH JAMES R. , ODYNIEC NORMAN A. , WALLACE ROBERT B.
Published: June 2012

Twenty-two patients had ventricular septal rupture complicating acute myocardial infarction. Sixteen of the 22 patients underwent surgical repair. The clinical findings, catheterization data, and operative results suggest that closure of the rupture should be delayed when possible from three to six weeks after the infarction to allow firm fibrous healing of the region. When surgery is thus delayed, the operative risks are smaller and the long-term results are good.
Systemic-Pulmonary Arterial Shunts in the First Year of Life
Authors: TRUCCONE NESTOR J. , BOWMAN FREDERICK O. , MALM JAMES R. , GERSONY WELTON M.
Published: June 2012

Results of systemic to pulmonary arterial shunts during the first year of life are reported in 86 infants under one year of age. Survival rates were highest in older patients and among infants whose basic cardiac defects were considered to be eventually amenable to surgical repair. Persistent hypoxia accounted for the majority of deaths. Congestive heart failure secondary to too large anastomoses occurred in 32.5% of Waterston shunts, but could be successfully managed medically in the majority of patients. Surgical revision of the shunt was accomplished successfully in two infants with subsequent alleviation of symptoms. Congestive heart failure occurred in only one of 26 patients after a Blalock shunt. Ten of the twelve patients in this series survived open-heart repair for cardiac lesions. It will eventually be necessary to compare these data with the results of single stage corrective surgery in the infant group.
Quantitation of Left-to-right Cardiac Shunts with Radionuclide Angiography
Authors: ANDERSON PAGE A. W. , JONES ROBERT H. , SABISTON DAVID C.
Published: June 2012

A quantitative radionuclide angiogram technique using an intravenous injection of technetium-99m (Tc-99m) pertechnetate is described for quantitation of left-to-right shunts in the central circulation. Data analysis assumes exponential indicator clearance from normal cardiac chambers by dilution. A late prolongation of tracer disappearance compared to the initial clearance rate indicates an abnormally early return of indicator to the cardiac chamber. Patients with left-to-right shunts demonstrate prolonged clearance of radioactivity from all cardiac chambers distal to the site of shunt. The magnitude of curve distortion is quantitatively related to the size of shunt, and counts recorded from the right lung are used for shunt quantitation. Quadratic regression analysis of data from 21 patients with left-to-right shunts and eight normal subjects demonstrated a correlation coefficient of 0.951 between measurements of left-to-right shunts by the radionuclide and by the Fick method. Observations on 14 patients with aortic or mitral valve disease revealed this method of shunt evaluation to be of limited value in the presence of severe cardiac valvular disease. However, the method permits detection of left-to-right shunts that are too small to be diagnosed by the Fick method and accurately quantitates shunts which are not at either extreme in size and flow. This technique appears to be potentially useful for the initial diagnosis and serial evaluation of patients with these disorders.
The Onset and Magnitude of the Contractile Response to Commonly Used Digitalis Glycosides in Normal Subjects
Authors: FORESTER WILBUR , LEWIS RICHARD P. , WEISSLER ARNOLD M. , WILKE THOMAS A.
Published: June 2012

Controversy exists over the rapidity of onset of the inotropic effect of various digitalis glycosides. Shortening of the systolic time intervals (STI) provides a quantitative measure of the inotropic effect of digitalis glycosides in human subjects. Total electromechanical systole corrected for heart rate (QS
2
I) is the most sensitive of the STI since it combines the shortening effect of digitalis glycosides on both the pre-ejection period and ejection time. Normal volunteer subjects were studied serially following i.v. injection of 1.6 mg cedilanid-D (C) (n = 18), 1.0 mg ouabain (O) (n = 12), 1.6 mg digoxin (D) (n = 16), and 1.6 mg digitoxin (DT) (n = 9). The shortening of QS
2
I was corrected for the molecular weight of the digitalis glycoside. The onset of shortening of the QS
2
I/ mole proved to be exponential for each digitalis glycoside. This allowed estimation of the maximum shortening of QS
2
I/mole (A) which would occur assuming zero excretion, from which the time constant (t
c
) of the curves could be determined. There was no significant difference in A among the digitalis glycosides. The t
c
, were 5.8 min (O), 7.2 min (C), 23 min (D), and 56 min (DT). These t
c
were significantly different except for O and C. Thus both C and O have a rapid onset of activity which is significantly shorter than either D or DT. The t
c
for C in patients with congestive heart failure is the same as normals. This study provides a heretofore unavailable, accurate measure of the differences among commonly used glycosides.
Comparison of Blood Flow Measured by Plethysmograph and Flowmeter During Steady State Forearm Exercise
Authors: LONGHURST JOHN , CAPONE ROBERT J. , MASON DEAN T. , ZELIS ROBERT
Published: June 2012

Forearm blood flow was determined at rest and during steady state grip exercise by the venous occlusion technique with a single strand mercury-in-rubber strain gauge plethysmograph and was compared with blood flow simultaneously determined by an electromagnetic flowmneter around the brachial artery before, during, and after intermittent isotonic grip exercise in eight subjects. The comparison of plethysmographic flow (
y
axis) with simultaneously measured flowmeter flow (
x
axis) yielded a correlation coefficient of 0.797, a slope of 1.15 and a
y
intercept of 9.62. When flow was normalized per 100 cc of forearm, the correlation coefficient was 0.823, the slope 1.21, and the
y
intercept 0.871. The overestimation of the flowmeter blood flow by the plethysmograph could be explained by flow through skin vessels which bypassed the flowmeter. When averaged plethysmographic flow was compared to total planimetered flowmeter flow during exercise, there was a 1.7 times overestimation by the former technique, which was constant over the range of exercise employed.
Pulmonary Diffusing Capacity in Disorders of the Pulmonary Circulation
Authors: BURGESS J. H.
Published: June 2012

The pulmonary diffusing capacity for carbon monoxide was measured by single breath (DcoSB) and steady state (DcoSS) techniques in 48 patients with various pulmonary circulatory disorders and the results compared with the type of hemodynamic abnormality. Patients with pure inflow obstruction (primary pulmonary hypertension, recurrent pulmonary emboli) had the lowest Dco (mean DcoSB = 14.3 ml/min/mm Hg [59%], mean DcoSS = 9.0 ml/min/mm Hg [58%]). Patients with inflow and outflow obstruction, (valvular heart disease with increased pulmonary vascular resistance [PVR]), had higher values (mean DcoSB = 16.2 [68%], mean DcoSS = 10.2 [65%]). In patients with pure outflow obstruction (valvular heart disease and normal PVR) Dco was normal (means 23.2 [96%] and 14.4 [87%] respectively). Patients with increased pulmonary blood flow (PBF), (left to right shunts), had the highest Dco (means 31.3 [118%] and 16.4 [106%]). There was a reciprocal relationship between Dco and PVR, a low Dco being characteristic of pulmonary inflow obstruction. Patients with increased PBF had lower Dco values than exercising normal subjects with comparable PBF. In patients with pulmonary circulatory abnormalities and no obstructive or restrictive lung disease, Dco is low when inflow obstruction predominates. Dco inceases with the addition of outflow obstruction and is above normal when there is an increased PBF and low PVR.
Pathophysiologic Correlations in Two Cases of Split His Bundle Potentials
Authors: BHARATI SAROJA , LEV MAURICE , WU DELON , DENES PABLO , DHINGRA RAMESH , ROSEN KENNETH M.
Published: June 2012

This is a pathophysiological correlation in two cases showing split His bundle potentials. The first case had a history of previous complete heart block and the electrophysiological studies revealed split His potentials with intact A-V conduction. Case two had split His potentials with complete heart block. Serial sections of the conduction system in both cases revealed calcific impingement on, and degenerative changes within the bundle of His with healthy bundle of His proximal and distal to the lesion.
Further Observations on Ventricular Tachycardia As Studied by Electrical Stimulation of the Heart
Authors: WELLENS HEIN J. J. , LIE K. I. , DURRER DIRK
Published: June 2012

Initiation and termination of tachycardia was studied by electrical stimulation of the heart in 14 patients with ventricular tachycardia (VT) not related to acute myocardial infarction (group A) and in six patients in whom the tachycardia occurred within 24 hours after the onset of acute myocardial infarction (group B). Results favor re-entry as the mechanism of tachycardia in group A patients. In group B abnormal automaticity seems more likely. In one patient with chronic recurrent VT the arrhythmia could be terminated by a single atrial premature beat. In a patient with Wolff-Parkinson-White syndrome and old myocardial infarction, VT could be initiated by a single atrial premature beat. One patient was studied while having VT during acute myocardial infarction and again five weeks later. In the acute phase of myocardial infarction no evidence for re-entry could be obtained; during the second study, however, ventricular tachycardias could be initiated and terminated by a single ventricular premature beat fulfilling the criteria of re-entry.
Rate Dependent Ventricular Ectopia Following Acute Coronary Occlusion
Authors: CHADDA KUL D. , BANKA VIDYA S. , HELFANT RICHARD H.
Published: June 2012

Recent reports have indicated that tachycardia as well as bradycardia may be arrhythmogenic in acute myocardial infarction. The present experimental study was designed to systematically evaluate the arrhythmogenic and antiarrhythmic effect of heart rate over a wide spectrum using sinus node crush and atrial pacing. Serial recordings of the surface electrocardiograms and local electrograms for a maximum period of three hours were taken at rates of 60-200 beats/min before and after ligation of the left anterior descending coronary artery in 24 open chested dogs. Immediately following coronary occlusion, the incidence of ventricular ectopic complexes was 7.6 ± 1.6/min at a rate of 60, and gradually decreased to 2.5 ± 0.4/min at a rate of 90 (
P
< 0.01). At rates of 110-150 ⪕ 1 ventricular ectopic complex/min was noted. However, at rates of 180 and above, the incidence of ventricular ectopic complexes dramatically increased with frank ventricular tachycardia and/or fibrillation being provoked on seventeen occasions. Similarly, at rates of 60-90, ventricular tachycardia and/or fibrillation was exhibited on sixteen occasions, but never at rates between 110-150. Local electrograms exhibited marked ST segment elevation with higher heart rates compatible with increased local ischemia. It is concluded that ventricular ectopia is more common at rapid as well as slow heart rates after acute coronary occlusion. There appears to be an optimal intermediate rate for maximal antiarrhythmic effect.
Value of Exploratory "Scanning" in the Echocardiographic Diagnosis of Ruptured Chordae Tendineae
Authors: GILES T. D. , BURCH G. E. , MARTINEZ E. C.
Published: June 2012

Echocardiographic diagnosis of rupture of the chordae tendineae to the anterior and posterior leaflets of the mitral valve may be difficult to make. Two patients, one with rupture of chordae tendineae to the posterior leaflet and the other with rupture of chordae tendineae to the anterior leaflet of the mitral valve, are reported to illustrate the use of an exploratory "continuous scanning" technique to facilitate and verify the echocardiographic diagnosis of these disorders. The elimination of confusing echocardiograms is emphasized.
Effects of Nitroglycerin on Left Ventricular Wall Motion in Coronary Artery Disease
Authors: DOVE JAMES T. , SHAH PRAVIN M. , SCHREINER BERNARD F.
Published: June 2012

The effects of sublingual nitroglycerin (GTN) on left ventricular wall motion (LVWM) were examined by angiographic assessment in eight patients with anginal chest pain. Five of seven patients having occlusive coronary artery disease showed segmental abnormalities in LVWM characterized by regional hypokinesis or akinesis at rest. These abnormalities were accentuated by tachycardia induced by atrial pacing and were associated with the development of anginal chest pain. Two patients with one vessel coronary artery disease had normal LVWM at rest, but developed abnormalities during the stress of tachypacing. Administration of GTN reversed the LVWM abnormalities in all patients despite continued tachypacing. One patient with atypical chest pain but normal coronary arteries had normal LVWM at rest, following tachypacing, and after GTN. It is concluded that angiographic evaluation of LVWM provides a useful measure of segmental myocardial ischemia in patients with suspected coronary artery disease, and permits objective assessment of effects of antianginal drugs in reversing myocardial ischemia.
The Syndrome of Systolic Click, Murmur, and Mitral Valve Prolapse-A Cardiomyopathy?
Authors: GULOTTA STEPHEN J. , GULCO LOUIS , PADMANABHAN VELLORE , MILLER STUART
Published: June 2012

Twenty six patients with systolic clicks, murmurs, and prolapsed mitral valve leaflets were studied because of distressing chest pain or troublesome arrhythmias. Cardiac catheterization revealed normal coronary arteries and a high incidence of left ventricular (LV) dysfunction.

The patients, 20 of whom were women, averaged 41 years of age. Thirteen of the 22 patients experienced chest pain of sufficient severity to warrant hospital admission for suspected acute myocardial infarction. Twenty of 26 had abnormal ECG patterns including sinus bradycardia, 1°, 2°, and 3° block, atrial and ventricular arrhythmias and abnormal ST-T wave vectors. Three had patterns of healed transmural infarctions and five of 16 had positive exercise tests.

LV dysfunction was hemodynamically documented in 20 patients by either elevated LV end diastolic pressure, low resting cardiac index, or inappropriate rise in cardiac index during exercise. In the remaining six, impaired LV dynamics were demonstrated angiographically.

Left ventriculography revealed mitral valve prolapse in all patients, mitral regurgitation in 20, and mild to severe LV hypertrophy in 14 patients. Contractility, determined angiographically, was markedly impaired in 13 patients with marked hypokinesis of the antero-lateral wall of the LV resulting in the appearance of an unusual prominent convexity in this portion of the ventricle in end systole and early diastole. Seven others had similar but less severe impairment of LV contractility.

These results indicate that LV dysfunction, possibly related to a primary myocardial disorder, is a significant component of the syndrome of prolapsed mitral valve leaflet. The findings in the symptomatic patients described in this study cannot be generalized to all patients with this syndrome as our sample excluded patients with mild asymptomatic forms of the disease.