bluuebunny/crossref_metadata_2025 huggingface dataset:
Surgery for Mitral Stenosis
Authors: BLAND EDWARD F.
Published: June 2012

The renewed interest in surgery for mitral stenosis is reviewed and the progress of the past five years summarized. The present status of the indirect operation (pulmonary-azygos shunt) is discussed, and the notable advances with the direct attack (finger-fracture valvuloplasty and commissurotomy) have been brought up to date (May 1951) by means of a survey of selected centers here and abroad.

Detailed information is available on 352 patients who have had an operation on the mitral valve. It is quite likely that the total now approaches 500 cases.

The over-all operative mortality has been 15 per cent. Post-operative embolism occurred in 6 per cent. Clinical improvement in the majority has been prompt and striking, and this has been fully supported by catheterization data. An appraisal of the more remote effects must await the passage of time.

Those most likely to benefit are patients under the age of 50 with only slight to moderate cardiac enlargement who are nevertheless seriously limited by pulmonary hypertension and congestion.

A formidable procedure of this magnitude should be reserved for those in trouble; it has no place in the management of patients with little or no disability.
Influence of Thyroidal Function on Vascular Reactivity in Dogs
Authors: PAGE IRVINE H. , MCCUBBLIN JAMES W.
Published: June 2012

Responsiveness to several vasoactive drugs has been found to be sharply reduced following suppression of thyroidal function with radioactive iodine, propylthiouracil or surgical thyroidectomy changed or increased with the appealance of the a thyroid state. Replacement therapy with desiccated thyroid did not restore vascular reactivity towards normal and produced inversion of adrenaline reesponses. Myxedema occurred in but 1 of 11 chronically athyroid dogs.
A Newly Modified Electromagnetic Blood Flowmeter Capable of High Fidelity Flow Registration
Authors: RICHARDSON ALFRED W. , DENISON ADAM B. , GREEN HAROLD D.
Published: June 2012

This paper describes a meter which, when inserted into an artery or vein, is capable of measuring the average flow, or the "instantaneous" flow throughout the heart cycle. Flow is recorded with a direct-writing instrument.
The Electrocardiogram in Heart Disease Detection
Authors: DAWBER T. R. , KANNEL W. B. , LOVE D. E. , STREEPER R. B.
Published: June 2012

In a study of a group of 2000 volunteers in a New England community the authors compare the relative merits of the 12-lead and a simplified lead I electrocardiogram in the detection of heart disease. The contribution the electrocardiograph would make if included in a heart disease screening program is evaluated. A possible heart disease screening method is suggested.
Endarteriectomy, or Surgical Restoration of the Lumen of an Obstructed Artery in Arteriosclerosis Obliterans
Authors: NÚÑEZ A. NÚÑEZ , MILANéS B. , IÑIGO J. RODRIGUEZ
Published: June 2012

Endarteriectomy is an operation originally proposed by Dos Santos in which a thrombus and the portion of the arterial wall to which it is attached are removed and the lumen of the artery re-established. The technic of this operation is described. Case histories of several patients illustrating the results which the authors have obtained are presented.
Observations on the Atria of the Human Heart by Direct and Semidirect Electrocardiography
Authors: WENGER R. , HOFMANN-CREDNER D.
Published: June 2012

By evaluation of direct electrocardiographic leads from the right atrium and semidirect esophageal leads from the left atrium, "atriodiagrams" have been constructed for both atria. The spread of activation in the atria has been studied under normal conditions as well as in cases of mitral heart disease, cor pulmonale, etc. In cases of doubtful enlargement of the left atrium, esophageal electrocardiograms may be helpful for diagnosis. In six cases of auricular flutter the results were not uniform.
Renal Tubular Secretion of Digoxin
Authors: STEINESS EVA
Published: June 2012

To study the mechanism of the renal handling of digoxin, simultaneous measurements of digoxin and inulin clearances were performed in 13 digitalized patients with congestive heart disease. The renal digoxin clearances exceeded inulin clearances, indicating an active tubular secretion of digoxin. No evidence of tubular backward diffusion was disclosed. Treatment with spironolactone (Aldactone) decreased the digoxin clearances, suggesting an inhibition of the tubular secretion of digoxin in the distal segment of the renal tubulus. After blocking the tubular secretion, the calculated renal clearances of nonproteinbound digoxin in plasma were similar to that of inulin, suggesting a glomerular filtration of free plasma digoxin. Plasma digoxin level rose during treatment with spironolactone.
Retrograde Radioisotope Myocardial Perfusion Patterns in Dogs
Authors: CIBULSKI ANTHONY A. , MARKOV ANGEL , LEHAN PATRICK H. , GALYEAN JAMES R. , SMITH ROBERT O. , FLOWERS WILLIAM M. , HELLEMS HARPER K.
Published: June 2012

A retrograde coronary vein injection technique for concentrating radioisotope in ischemic myocardial regions was evaluated in dogs. Potassium-43 in saline solution was injected into the coronary veins during complete closure of the coronary sinus. In the presence of coronary inflow obstruction, the venous potassium-43 was distributed mainly to the low pressure vessels in ischemic heart regions; i.e., the ratio of potassium-43 in the occluded-to-unoccluded areas ranged from 2:1 to 3:1 thirty seconds after retrograde injections. Krypton-85 in saline solution was injected under pressure into the coronary veins during partial closure of the coronary sinus. In the presence of inflow obstruction, the ratio of krypton-85 in the occluded- to-unoccluded areas ranged from 4:1 to 6:1 sixty seconds after retrograde injections; larger ratios may be expected after rapid washout of gas from the normally perfused region is nearly complete. Myocardial potassium-43 imaging techniques were applied to locate and measure the size of the ischemic heart region as a radioisotopic hot spot. Detection of hypoperfused areas of extremely small size may be accomplished by this technique.
Aorticopulmonary Septal Defect Coexisting with Ventricular Septal Defect
Authors: TANDON RAJENDRA , DA SILVA CYRO LUIZ , MOLLER JAMES H. , EDWARDS JESSE E.
Published: June 2012

Three cases, in each of which an aorticopulmonary septal defect (AP window) coexisted with a ventricular septal defect, are described. In two the ventricular septal defect was of the usual variety, and in one it was part of the tetralogy of Fallot.

The patients presented as examples of congestive cardiac failure with a large left-to-right shunt in infancy. Aortography was the most reliable method for identification of the AP window when a ventricular septal defect was associated. Associated features included a right aortic arch with mirror image branching in the first case and tetralogy of Fallot with muscular subaortic stenosis in the third case. In the case with the tetralogy of Fallot, the effects of pulmonary stenosis were masked by the left-to-right shunt through the AP window.
A Method for Evaluating Computer Programs for Electrocardiographic Interpretation
Authors: BAILEY JAMES J. , HORTON MARTHA , ITSCOITZ SAMUEL B.
Published: June 2012

A simple method for testing reproducibility in ECG computer program performance results from using two digital representations of the same analog ECG tracing. Each digital representation is separated from the other by one millisecond in time. When the digital representations are processed by the Mayo Clinic program (1968), the diagnostic statements are identically reproduced in only 60% of 33 tracings. When the method is applied to version D of the PHS program and to the newly released IBM program of 1973, identical reproducibility is 43.3% and 76.0%, respectively, of 217 tracings. After analog filtering these figures are improved to 49.8% and 79.7%, respectively. These results show that reproducibility is most affected by a program's algorithms for pattern recognition, measurement, consistency checking, and noise handling. Reproducibility is less affected by attenuation of high frequency noise at the analog level. The relationship of reproducibility to program error rate in previous studies is discussed. Hence poor performance on this test obviates the need for a more time-consuming clinical evaluation. The need for human overview and quality checking is re-emphasized.
Enhancement of Electrical Stability of Acutely Ischemic Myocardium by Edrophonium
Authors: HARRISON LURA A. , HARRISON LYNN H. , KENT KENNETH M. , EPSTEIN STEPHEN E.
Published: June 2012

Recently we demonstrated that vagal stimulation increases ventricular fibrillation threshold (VFT) and decreases the incidence of spontaneous ventricular fibrillation during acute coronary occlusion. Assuming this protective effect of the vagus to be mediated through acetylcholine release, we hypothesized that inhibition of acetylcholinesterase, a potential clinical intervention, would also enhance electrical stability of acutely ischemic myocardium. A balloon cuff was placed around the left anterior descending coronary artery (LAD) and left ventricular and atrial electrodes were implanted in 10 dogs. Five to seven days later VFT was determined (VFT was defined as the minimum current required to produce ventricular fibrillation). During nonischemic conditions VFT was 42 ± 8 ma; when edrophonium was infused (1-2 mg/kg/min), VFT increased to 77 ± 11 ma (
P
< 0.005). During ischemia induced by LAD occlusion VFT fell to 19 ± 4 ma. Edrophonium increased VFT during ischemia to 52 ± 13 ma (
P
< 0.005), a level not significantly different from preischemic values. These results suggest that enhanced electrical stability of ventricular myocardium produced by vagal stimulation is mediated by acetylcholine release, and that inhibitors of acetylcholinesterase may provide a new means of therapy for arrhythmias occurring during acute myocardial ischemia.
The Electrocardiographic Features of Acute Cardiac Tamponade
Authors: FRIEDMAN HOWARD S. , GOMES JOSEPH A. , TARDIO ANTHONY R. , HAFT JACOB I.
Published: June 2012

To test the hypothesis that the electrocardiogram of cardiac rupture is due to acute cardiac tamponade, 27 episodes of cardiac tamponade were produced in ten open-chest dogs. During continuous monitoring of the electrocardiogram and the arterial and venous pressures, 10-30 cc of autologous, heparinized blood, or one of several other solutions, were intermittently infused into the pericardial sac until no effective blood pressure was recorded. The characteristic electrocardiographic findings of acute cardiac tamponade were peaked P waves, decrease of QRS complex voltage, left axis deviation of the QRS complex, deep T wave inversions, and ST-segment change. With the appearance of electromechanical dissociation, there was a sudden, vagally-mediated bradycardia. Because these changes are similar to those observed at the time of cardiac rupture, it was concluded that the electrocardiographic manifestations of cardiac rupture could be attributed to acute cardiac tamponade.
Angiographic Estimation of Right Ventricular Volume in Man
Authors: GENTZLER RICHARD D. , BRISELLI MICHAEL F. , GAULT JAMES H.
Published: June 2012

Although the feasibility of angiographic estimation of right ventricular (RV) volume (V) has been demonstrated, no method has been validated by comparison with independent measurements of volume, and none has been applied to the systematic analysis of RVV characteristics in man. In the present study, postmortem casts of the human RV were used to determine a regression analysis for RVV for biplane frontal and lateral films by the Simpson's rule technique (true volume = 0.749 calculated volume,
r
= 0.99,
see
3.7 ml, for casts ranging in volume from 20 to 115 ml). This method was then employed to estimate RVV from biplane cineangiograms of 32 patients. The validity of RVV measurements
in vivo
was corroborated by close correlation of stroke volumes estimated independently by angiographic and indicator dilution methods (
r
= 0.98,
see
4.1 ml).

In nine patients with normal RV hemodynamics RV end-diastolic volume (EDV) averaged 81 ml/m
2
(range 63 to 101 ml/m
2
); ejection fraction (EF) averaged 0.51 (range 0.40 to 0.66), values generally lower than the normal left ventricular EF. Of 14 patients with elevated RV systolic pressure (> 45 mm Hg), normal RV function was evidenced in eight by normal levels of EF and EDV; in the remaining six patients, EF was reduced and EDV was elevated, suggesting that dilatation occurred in these patients as a function of depressed RV myocardial performance. In six patients with left-to-right shunts RV EDV was also increased; however, in these patients normal levels of EF were observed, indicating that the accommodation to volume overload was accomplished through the Starling mechanism. Finally, in six of 13 patients with reduced levels of cardiac output, RV EDV was increased and EF reduced, signifying that impaired RV myocardial function contributed to depression of over-all cardiac performance. It is concluded that the biplane angiographic method provides a practical, accurate means of quantitating RVV characteristics, including the magnitude of volume overload as well as the level of RV myocardial performance.
Artifacts in First and Second Sounds of the Phonocardiogram
Authors: CASTILLO HORACE T.
Published: June 2012

Phonocardiographic instrumentation tests using a square wave of sound pressure reveal differentiation spikes at the output of a dynamic microphone and at the amplifier-filter during initial onset of the test pulse. When the pulse reaches the plateau level, ringing oscillations can be observed in the amplifier-filter combination. Microphone differentiation and filter ringing are also present at removal of the test pulse. These artifacts can be observed as a frequency distortion at the beginning and end of the first and second heart sounds in the normal phonocardiogram. By observing the characteristics of these artifacts investigators and clinicians may be assisted in improving their understanding of heart sound recordings. It is suggested that clinicians use the square wave test to determine the distortion unique to their equipment.
Computer Analysis of the Orthogonal Electrocardiogram and Vectorcardiogram in Mitral Stenosis
Authors: WALSTON ABE , HARLEY ALEXANDER , PIPBERGER HUBERT V.
Published: June 2012

Orthogonal electrocardiograms (Frank lead system) from 191 patients with pure mitral stenosis (MS) were compared to electrocardiograms from 510 normal patients and 296 patients with pulmonary emphysema (PE). All patients with MS underwent right heart catheterization; 121 patients underwent both left and right heart catheterization. Three hundred and thirty electrocardiographic measurements were obtained from each record and tested for their ability to distinguish mitral stenosis from normal. Two sets of diagnostic discriminators were selected: (1) ECG measurements which can be easily obtained by hand and (2) measurements which performed best in multivariate analysis using linear discriminant functions. The patients with mitral stenosis were separated into three hemodynamic subgroups according to mean pulmonary artery pressure (PAP) (0-30, 31-40, and > 40 mm Hg). The ability of the selected measurements to recognize mitral stenosis increased as mean pulmonary artery pressure rose. The superiority of the multivariate technique, using nine measurements simultaneously, was readily demonstrated when compared to the hand measurements. At a constant level of 6% false positives, multivariate analysis allowed a 74% recognition rate of mitral stenosis compared to 44% with hand measurements.
The Anatomic Substrate of Complete Left Bundle Branch Block
Authors: LEV MAURICE , UNGER PAUL N. , ROSEN KENNETH M. , BHARATI SAROJA
Published: June 2012

The conduction systems of eight cases diagnosed clinically as having complete left bundle branch block (LBBB) were serially sectioned. Left axis deviation was present in six and normal axis in two. In all cases there was evidence of ischemia of the myocardium and left bundle branch (LBB) in various parts of the coronary circulation. In all cases, the LBB showed pathologic change at its junction point with the bundle of His, with disruption, complete or incomplete, in six, and with recent and old lesions in two. There was no difference in lesions of the LBB between cases with and without left axis deviation. There is thus complete correlation between the electrocardiographic abnormality LBBB and lesions of the LBB in these cases. The pathogenesis of the LBB lesions in these cases is probably both ischemic and mechanical.
Retrograde Invasion of the Bundle Branches Producing Aberration of the QRS Complex During Supraventricular Tachycardia Studied by Programmed Electrical Stimulation
Authors: SPURRELL ROWORTHA A. J. , KRIKLER DENNIS M. , SOWTON EDGAR
Published: June 2012

Four patients with paroxysmal supraventricular tachycardia have been studied using programmed electrical stimulation of the heart and intracardiac recordings. One patient had an atrioventricular (A-V) junctional tachycardia, possibly due to a rapidly discharging protected ectopic focus, and three patients had anomalous atrioventricular connections. The ECG recordings in all four patients showed a bundle branch block pattern during tachycardia, and normal intraventricular conduction could be produced by suitably timed right ventricular premature beats. The cycle length of the tachycardia was shorter with normal intraventricular conduction than in the presence of a bundle branch block pattern in two patients. Evidence is presented indicating that the bundle branch block during tachycardia was likely to be due to concealed retrograde conduction of the appropriate bundle branch, and in the presence of an anomalous bypass, the cycle length of the tachycardia depended on the anatomical relationship of the anomalous bypass to the blocked bundle branch.
A New Method for Radionuclide Imaging of Acute Myocardial Infarction in Humans
Authors: PARKEY ROBERT W. , BONTE FREDERICK J. , MEYER STEVEN L. , ATKINS JAMES M. , CURRY GEORGE L. , STOKELY ERNEST M. , WILLERSON JAMES T.
Published: June 2012

A new method of visualizing acute myocardial infarction in humans following intravenous injection of 15 mCi-5 mg of
99m
Tc stannous pyrophosphate in 23 patients is reported. Fifteen patients had histories suggestive of acute myocardial infarction and subsequently developed electrocardiogram and enzyme changes that confirmed the clinical diagnosis. Eleven of the 15 patients were scanned 3-5 days postinfarction, and all had positive scintigrams. The four remaining patients were scanned 7-10 days after their myocardial infarction; two had positive scintigrams. In those 8 patients with chest pain but without ECG and enzyme changes suggestive of myocardial infarction, scintigrams were negative. Positive scintigrams in the patients with myocardial infarction are thought to be due to incorporation of pyrophosphate into the crystalline structure of the hydroxyapatite found within the mitochondria of irreversibly damaged myocardial cells. The location of the acute myocardial infarction by scintigram correlated well with ECG localization in the 13 patients with positive scintigrams. This imaging method shows promise in 1) identifying the presence of acute myocardial infarction in patients with chest pain, 2) determining the location of acute myocardial infarction with a high degree of accuracy, 3) detecting the extension of the infarction, and 4) the possibility of determining the size of acute myocardial infarctions.
The Effect of Aortocoronary Bypass Grafts on Myocardial Blood Flow Reserve and Treadmill Exercise Tolerance
Authors: KNOEBEL SUZANNE B. , MCHENRY PAUL L. , PHILLIPS JOHN F. , LOWE DANIEL K.
Published: June 2012

Twenty-five patients had myocardial blood flow reserve determinations (percentage increase in myocardial blood flow with stress), treadmill exercise tests and coronary and bypass cineangiography pre- and postaortocoronary bypass surgery. Twenty of the patients had the postoperative studies performed three months after operation, three at two months and two at five and six months, respectively.

Eleven of the 25 patients had all significant coronary artery obstructions (75% or greater) bypassed and all grafts were open at the time of restudy. Preoperatively, blood flow reserve had been abnormal in nine and all had positive treadmill tests. Postoperatively, all eleven patients had normal myocardial blood flow response to stress and treadmill tests were negative in ten (one patient was not restudied on the treadmill).

In six patients, no patent grafts could be demonstrated. These patients continued to show abnormal blood flow reserve and positive treadmill studies.

Eight of the 25 patients had partial revascularization in that some grafts were open, some closed, and some significantly occlusive lesions were not bypassed. Four of these eight patients had normal flow and treadmill studies and the remainder continued to have an abnormal response to one or both of the measurements.

The relationship between treadmill exercise response, myocardial blood flow reserve, and graft patency was significant at the 0.005 level for patients with all grafts open or closed. No significant correlation was obtained between any of the measurements in those patients with partial revascularization.

The data indicate that successful aortocoronary bypass grafting provides myocardial revascularization as reflected in a return to normal of the myocardial blood flow reserve and response to treadmill stress testing.
Effects of Chronic Digoxin Administration on Left Ventricular Performance in the Normal Conscious Dog
Authors: MAHLER FELIX , KARLINER JOEL S. , O'ROURKE ROBERT A.
Published: June 2012

The effects of chronic digoxin administration on left ventricular (LV) function were studied in six healthy conscious dogs, instrumented with high-fidelity LV manometers and endocardial ultrasonic diameter gauges. Studies were performed at an average of eight days after a therapeutic serum level of digoxin had been achieved by daily intramuscular injections. In the resting state, at matched heart rates and at unchanged LV end-diastolic pressures, LV systolic pressure increased after digoxin by a mean of 9 mm Hg (
P
< 0.008), while peak LV dP/dt was augmented by 38% (
P
< 0.006). Mean and maximal velocity of circumferential fiber shortening (VCF) increased by 22% and 21%, respectively (both
P
< 0.02), and LV systolic diameter excursion (ΔLVD) increased by 10% (
P
< 0.05) above control values. Intravenous propranolol did not alter these responses significantly. Elevation of LV systolic pressure to an average of 206 mm Hg by phenylephrine infusion did not change the previous basal augmentation of LV dP/dt and VCF produced by digoxin, but ΔLVD exceeded the control values by 25% as compared with the increase of 10% produced by digoxin alone (
P
< 0.02). Thus, chronic digoxin administration in the normal conscious dog exerts a potent positive inotropic effect in the resting state and markedly improves cardiac reserve as evidenced by enhanced LV performance during acute pressure overloading.
Adolescent Hypertension
Authors: KILCOYNNE MARGARET M.
Published: June 2012

Two groups of patients were recognized among 27 black and latin adolescents who underwent diagnostic evaluation for hypertension. Group I consisted of ten patients, seven of whom had arterial pressures consistently higher than 1 standard deviation above the pressure means of normal adolescents and three had pressures below this level. Group II consisted of 17 patients, 16 of whom had systolic and diastolic pressures greater than 2 standard deviations above the means for their age-sex group. One patient had solely systolic hypertension. An assignable cause for their hypertension was not apparent. Chemical parameters, including plasma renin activity (radioimmunoassay Angiotensin I), were similar to those observed in adult hypertensive patients of the same community. A difference in response to therapy was noted in adolescents compared to adults which may imply differences in the mechanisms involved at this phase of the disease, as has been reported in patients with labile and early hypertension and spontaneously hypertensive rats.

At least three facets of this adolescent hypertension study deserve implementation and investigation: 1) routine blood pressure measurements in high schools, 2) longitudinal evaluation of the indications for and effects of therapy, and 3) intensive inquiry into the hemodynamic and neurohumoral aspects of hyperten- sion in its early unfolding.
Systemic and Coronary Hemodynamic Effects of Diazepam in Patients with Normal and Diseased Coronary Arteries
Authors: CÔTÉ PIERRE , GUÉRET PASCAL , BOURASSA MARTIAL G.
Published: June 2012

In 12 patients with significant coronary artery disease (group I) and in eight patients with normal coronary arteries (group II), 5 to 8.5 mg of diazepam was given intravenously before coronary angiography. Adequate sedation was obtained in 17 patients. Hypoventilation occurred in all patients but was without clinical correlate. Coronary and cardiovascular effects were assessed before as well as 10 and 20 min after diazepam. Heart rate was unchanged and aortic pressure (AP) decreased significantly (
P
< 0.01) in most patients. Cardiac index decreased only in patients of group II (
P
< 0.01). Of particular interest was a constant fall in left ventricular end-diastolic pressure (LVEDP) in both groups, (
P
< 0.01) and (
P
< 0.05) at 10 and 20 min respectively in group I and (
P
< 0.01) at 10 and 20 min in group II. Tension-time index and myocardial oxygen consumption (MVO
2
) were also significantly decreased (
P
< 0.05) after diazepam in both groups. Since neither coronary blood flow nor coronary vascular resistance were modified by diazepam, the fall in LVEDP could be due to a decrease in AP (afterload) and/or in venous return (preload). The combination of these effects could reduce intra-cavitary volume, myocardial wall tension and left ventricular MVO
2
. Our data therefore suggest that, in addition to its central sedative effects, diazepam also has a nitroglycerin-like action on the coronary and systemic circulation.
Internal Mammary Artery Versus Autogenous Vein for Coronary Artery Bypass Graft
Authors: ROSSITER STEPHEN J. , BRODY WILLIAM R. , KOSEK JON C. , LIPTON MARTIN J. , ANGELL WILLIAM W.
Published: June 2012

Aortocoronary venous graft (ACVG) and internal mammary artery graft (IMAG) are currently the two most popular choices for coronary artery bypass. The morphologic alteration and susceptibility to atheromatous degeneration of the IMAG were compared with the ACVG. Six of 12 surviving dogs with IMAGs were fed a hyperlipidemic diet and six were placed on a regular diet. All dogs were sacrificed 3-15 months after surgery. Twelve of 28 long-term surviving dogs with ACVGs were also on hyperlipidemic diets, and all were sacrificed 3-18 months after surgery. Arteriography and electron microscopy were performed in selected cases, and histology was performed in all cases. All long-term IMAGs remained patent; 83 percent (5/6) "regular" diet arteries were normal, with no intimal proliferation, while 33 percent (2/6) "hyperlipidemic" IMAGs had diffuse atheroma. Eighty-two percent of ACVGs revealed significant atherosclerosis. Severity of arteriosclerotic involvement of the ACVG was far greater than that of the native coronary circulation; this was not true for the IMAG.

It may be concluded that (1) in the normolipidemic condition the IMAG undergoes significantly less severe histologic change than the ACVG, (2) both the IMAG and the ACVG are more susceptible to atheromatous change than the native coronary circulation. In these series, patency was not influenced by severity of histologic changes, and no grafts were occluded by virtue of the arteriosclerotic process.
Anatomically corrected malposition of the great arteries (S, D, L).
Authors: Van Praagh R , Durnin R E , Jockin H , Wagner H R , Korns M , Garabedian H , Ando M , Calder A L
Published: June 2012

Two autopsy-proved cases are presented of a rare form of congenital heart disease, anatomically corrected malposition (S, D, L). Anatomically corrected malposition means that despite the abnormal relationship between the great arteries, the aorta arises nonetheless above the anatomically left ventricle and the pulmonary artery originates above the anatomically right ventricle. (S, D. L) briefly indicates the segmental set or combination: situs solitus of viscera and atria (S), ventricular D-loop (D), AND L-MALPOSITION OF THE GREAT ARTERIES (L). These are the first cases of anatomically corrected malposition (ACM) in whom the presence of a subaortic muscular conus only has been documented pathologically. This established that ACM can occur with a subaortic conus, as well as with a bilateral conus. From the diagnostic standpoint, the distributions or epicardial courses of the coronary arteries are recommended as a helpful approach to ventricular identification. This diagnostic method has widespread angiocardiographic and surgical applications. Symbolic terminology, exemplified by anatomically corrected malposition (S, D. L) is brief and accurate. This approach may conveniently be applied to many other forms of comples congenital heart disease, and it considerably facilitates computer data processing.
Eectrophysiological observations in pateints with rate dependent bundle branch block.
Authors: Denes P , Wu D , Dhingra R C , Amat-y-leon F , Wyndham C , Rosen K M
Published: June 2012

Electrophysiological studies were conducted in 15 patients with tachycardic rate dependent bundle branch block (RDBBB): ten with left, and five with right. No bradycardic RDBBB was observed, despite occurrence of cycle lengths (CL) longer than 1200 msec in over half the patients studied. Onset of RDBBB was abrupt in 13 patients, and gradual in two. In three patients, the CL allowing reversion to normal conduction (once RDBBB was initiated) was 50, 55, and 190 msec longer, respectively, than the CL inducing RDBBB. Bundle brance refractory periods (RP) were measured with atrial extrastimulus technique in five patients. All RP (except one) were prolonged at all tested CL when compared to patients without conduction disease. The expected decrease in RP with shortening of CL did not occur in four of the five patients. The electrophysiological abnormality in patients with DBBB thus appeared to be an increase in refractoriness in the affected bundle branch, along with a loss of the normal decrease in refractoriness with decrease in CL. Similar findings might be demonstrable in patients with early bundle branch disease.
Acute myocardial infarction in toxic cardiomyopathy without coronary obstruction.
Authors: Regan T J , Wu C F , Weisse A B , Moschos C B , Ahmed S S , Lyons M M
Published: June 2012

Confluent left ventricular scar without significant coronary obstruction has been found in alcoholic subjects at autopsy. To evaluate the pathogenesis, 12 patients with chronic alcoholism and severe precordial pain persisting 4-24 hours were observed clinically. Cardiac isoenzymes of lactic dehydrogenase rose in serum. ST segment was elevated in anterior or posterior ECG leads, and abnormal Q waves appeared. Hypertnesion and hypercholesterolemia were present in two (group B) but not in the ten (group A). The latter exhibited no significant obstructive disease, based on coronary angiography in seven survivors and postmortem examination of the remaining three. Clinical evidence, as well as the quantitative assessment of platelets, made arterial thromboembolism an unlikely cause for the symptoms. Neither hemotologic or systemic disease affecting myocardium was present. The morphology of the left ventricle in three autopsies was compared with that of patients with alcoholism who had no cardiac disease, cardiomyopathy, or an asymptomatic scar. All had accumulation of Alcian positive glycoprotein in the interstitium. The patients with cardiac disease also had interstitial fibrosis which was characterized, particularly in the acute infarction group, by concentric periarterial fibrosis. Restriction of coronary vasodilation by this process during periods of high blood flow requirements was postulated as a basis for infarction.
Echocardiographic observations on ventricular septal rupture complicating acute myocardial infarction.
Authors: Chandraranta P A , Balachandran P K , Shah P M , Hodges M
Published: June 2012

Echocardiograms were performed on three patients with ventricular septal rupture complicating myocardial infarction. The pulmonary artery mean pressure was 30 mm Hg or more in all three patients. The size of the ventricular septal defect, determined at operation or autopsy, was 2 cm or greater in each patient. The salient echocardiographic abnormality was dilatation of the right ventricle. The direction of septal motion was normal in all the patients. The left atrial diameter was slightly increased in one patient and was normal in the other two. In one patient, and unusual pattern of mitral valve motion was seen. Complete closure of the reopening of the valve. This pattern was suggestive of increased blood flow through the mitral valve. Although some of these findings are nosspecific, the combination of echocardiographic findings may provide useful clues to the diagnosis of septal perforation.
A simplified method for quantitating left-to-right shunts from arterial dilution curves.
Authors: Victorica B E , Gessner I H
Published: June 2012

This report presents a new, simple and reliable method of quantitating left-to-right shunts from arterial dilution surves. When indicatior (e,g., indocyanine green) is injected centrally (right venticle or pulmonary artery) and blood is withdrawn rapidly from either the aorta or other central systemic artery, in the presence of a left-to-right shunt to recorded indicator-dilution curve usually shows two discrete peaks: p-1 of the magnitude of the shunt expressed as percent of pulmonary blood flow, Experimental and clinical data demonstrate that this method is accurate in quantitating shunts from such curves.
Thallium-201 for myocardial imaging. Relation of thallium-201 to regional myocardial perfusion.
Authors: Strauss H W , Harrison K , Langan J K , Lebowitz E , Pitt B
Published: June 2012

Following intravenous administration, the myocardial concentration of tracer thallium-201, potassium-43, and rubidium-81 were determined in mice; thallium was present in the greatest concentration in the myocardium (2.08% compared 1.25% for potassium and 1.15% for rubidium at 10 minutes). The regional myocardial distribution of thallium-201 was determined in dogs under conditions of normal flow, and total occlusion, and compared with potassium-43 (r=0.97). The regional distribution of thallium-201 was compared to microspheres under conditions of partial occlusion and reactive hyperemia (r=0.97). Thallium-201 was evaluated in a series of phantom scans, which demonstrated that the low energy X-ray of thallium was suitable for imaging. These results suggest that thallium-201 can be used for the evaluation of the distribution of regional myocardial perfusion.
Lack of sensing by demand pacemakers due to intraventricular conduction defects.
Authors: Vera Z , Mason D T , Awan N A , Hiliard G , Massumi R A
Published: June 2012

A previously unrecognized form of failure of normally functioning noncompetitive R-inhibited or R-triggered pacemakers to sense is described in 30 patients. The failure was produced by the delayed arrival of ventricular depolarization due to intraventricular conduction disturbances at the site of pacemaker sensing electrodes. These patinets with late activation of the right ventricle exhibited right bundle branch block (RBBB) during conducted sinus beats or had ectopic beats arising from the left ventricle. In both these situations, several late occurring QRS complexes were not sensed by the pacemaker electrodes in the right ventricular apex (RVA) and thereby the R-inhibited pacemaker spike discharged into the initial portion of the QRS complex. Activation of the RVA was delayed up to 65 msec in sinus beats with RBBB and even longer in premature beats arising from the left ventricle. The depolarization front of such beats reached the myocardium around the right ventricular pacemaker electrodes late in the QRS and thereby were not sensed up to 65 msec after the QRS onset as seen on the surface electrocardiogram (ECG). It was found in this study that if the inscription of such QRS complexes began up to 65 msec before the next due pacemaker impulse, these complexes were not sensed, allowing discharge of normally functioning R-inhibited pacemakers within the QRS which mimicked pacemaker malfunction. Failure to sense due to this phenomenon was observed in patients with noncompetitive pacemakers, both R-inhibited and R-triggered; temporary and permanent; with unipolar as well as bipolar electrodes. Similarly, patients with left ventricular epicardial electrodes and left bundle branch block in sinus beats also exhibited this phenomenon. Complete evaluation proved that pacemaker function was normal in the entire patient group. Recognition that failure to sense was the result of intraventricular conduction disorder prevented the untimely replacement of the pulse generator. This phenomenon of nonsensing by noncompetitive pacemakers should be considered in the presence of wide QRS complexes before the pacemaker is concluded to be malfunctioning.
Double accessory pathways in Wolff-Parkinson-White syndrome.
Authors: Castellanos A , Agha A S , Befeler B , Myerburg R J
Published: June 2012

Intracardiac electrophysiological studies were performed in two patients with Wolff-Parkinson-White (WPW) syndrome. Atrial pacing at increasing rates or shorter coupling intervals produced inscription of the forward His bundle deflection at progressively longer intervals after the onset of ventricular depolarization. There was an associated increase in QRS duration without any change in the P-R (or St-V) interval. This response was consistent with a Kent bundle. Case 1 also had a short A-H interval which did not show the expected prolongation with stimulation at progressively faster rates. This suggested the presence of a James bundle in addition to the Kent bundle. In case 2 beats conducted exclusively through the atrioventricular (A-V) node had a short H-V interval but a delta wave was not inscribed. Absence of an initial slurring was attributed to the existence of an infra-His bundle bypass of the Mahaim type causing only slight pre-excitation, which was not of sufficient magnitude to be recorded by body surface leads. However, the existence of a congenitally short anterosuperior division of the left bundle could nt be excluded.
Purkinje repolarization as a possible cause of the U wave in the electrocardiogram.
Authors: Watanabe Y
Published: June 2012

Our recent clinical studies suggest that the U wave represents Purkinje repolarization. To test this hypothesis, transmembrane potentials of Purkinje fibers (P) and the ventricular muscle (V) were simultaneously recorded from canine P-V preparations perfused in a tissue bath, and effects of various factors causing prominent U waves were studied. These include low stimulating frequency (bracycardia), low potassium (K) concentration, hypothermia, and quinidine. Bracycardia increased the difference between action potential duration of P and V, and decreased the rate of repolarization in P. Similarly, the difference of P and V action potential duration was increased markedly by low K and hypothermia, and slightly by quinidine, while the slope of phase 3 was significantly decreased by all these factors. In several intact animals either hypokalemia or hypothermia was produced using hemodialysis or extracorporeal circulation, and recorded electrocardiograms were compared with the P and V action potentials obtained under similar perfusing conditions in subsequent tissue bath study. Such comparison revealed a good temporal correlation between phase 3 repolarization in P and the electrocardiographic U wave. These results, although indirect, appear to support the theory that P repolarization caused the genesis of the U wave.
Influence of hypertonic mannitol on ventricular performance and coronary blood flow in patients.
Authors: Willerson J T , Curry G C , Atkins J M , Parkey R , Horwitz L D
Published: June 2012

The influence of a relatively small increase in serum osmolality produced by hypertonic mannitol on ventricular and systemic arterial hemodynamics and coronary blood flow was studied in 20 patients undergoing cardiac catheterization. Mannitol given to increase serum osmolality 10 mOsm resulted in a small but significant increase in mean systemic arterial pressure, maximum LV dp/dt, left ventricular end-diastolic pressure and cardiac output but no significant change in heart rate or hematocrit. The most prominent change in the patients studied, however, was in coronary blood flow which increased 39% after mannitol. Patients with severe two and three vessel coronary artery disease had increased in coronary blood flow similar to those in patients without coronary artery disease. The data suggest the need to further evaluate the physiological importance of the increase in coronary blood flow produced by mannitol in patients with coronary artery disease and indicate the possibility that mannitol might be of value in treating certain problems in patients with coronary artery disease,
Splanchnic blood flow in essential hypertension and in hypertensive patients with renal artery stenosis.
Authors: Messerli F H , Genest J , Nowaczynski W , Kuchel O , Honda M , Latour Y , Dumont G
Published: June 2012

Splanchnic blood flow (SBF) was measured simultaneously with cardiac output (dye dilution) and intrarterial blood pressure by constant infusion of indocyanine green in 11 control subjects, 13 patients with essential hypertension (EH) and seven hypertensive patients with renal artery stenosis (RAS). The cardiac index (CI) was lower (P less than 0.05) in patients with EH (3.17 plus or minus 0.07 L/min/m-2) (mean plus or minus SEM) than in control subjects (3.43 plus or minus 0.09). Associated with the lower CI was a significantly (P less than 0.01) lower SBF (0.797 plus or minus 0.02 L/min/m-2 vs 0.889 plus or minus 0.04). Patients with RAS presented with higher (P less than 0.01 vs EH, nonsignificant vs control subjects) cardiac index (3.66 plus or minus 0.17) and even lower SBF (0.749 PLUS OR MINUS 0.02). Furthermore, there was a negative correlation (r = - 0.652) between the mean arterial pressure and the SBF when results for all patients were considered. The correlation remained (r = - 0.568) in the EH group and the slope of regression line was not different from that for all subjects. The CI and SBF were weakly correlated (r = 0.423) in control subjects and patients with EH, whereas in patients with RAS, a negative correlation was found (r = - 0.778). This study indicates that the SBF, although significantly decreased in patients with EH, remains proportional to the CI in control subjects and in essential hypertensive patients. No redistribution of CI in regard to the splanchnic circulation occurs in EH. In contrast, in patients with RAS a dissociation of CI and SBF occurs and the fraction of the CI which passes through the splanchnic vascular bed is markedly reduced. The close correlation between mean arterial pressure and SBF suggests that both parameters are influenced by a common pathophysiological factor.
Smoking and fibrinolysis.
Authors: Janzon L , Nilsson I M
Published: June 2012

In order to study the fibrinolytic activity of vein walls in smokers and nonsmokers, 71 randomly selected heavy smokers, i.e., smoking more than 15 g tobacco per day, and 41 nonsmokers from the population group "Men born in 1914 residing in Malmo" were invited to undergo a health examination. When examined after 12 hours' abstention from tobacco, the smokers were found to have the same fibrinolytic activity as nonsmokers. Out of the 71 heavy smokers, 31 refrained from smoking during 8-9 weeks (as monitored with questionaire and COHb-determinations). Neither in those who had abstained from smoking nor in the controls did the fibrinolytic activity differ from that initially recorded. In a randomly selected subsample of 19 individuals examined after only one week's abstention from tobacco, the fibrinolytic activity, after venous occlusion of forearms, tended to be lower in the blood as well as in superficial hand veins, but the difference was not significant. The effect of smoking six cigarettes during three hours was measured. This level of smoking was associated with an increased fibrinolytic activity in blood, measured as euglobulin clot lysis time, and in superficial hand veins. This increase is probably due to the combined effects of nicotine and carbon monoxide.
Dose response effectiveness of propranolol for the treatment of angina pectoris.
Authors: Alderman E L , Davies R O , Crowley J J , Lopes M G , Brooker J Z , Friedman J P , Graham A F , Matlof H J , Harrison D C
Published: June 2012

Seventeen patients received placebo medication during a 12-week run-in period, followed by four double-blind study periods of six weeks each, during which time placebo, 80 mg, 160 mg and 320 mg propranolol dosages were administered. Examination of the frequency of angina episodes and nonprophylactic nitroglycerin consumption revealed significant beneficial clinical responses for both the 160 and 320 mg dosages. Exercise testing also demonstrated increased exercise tolerance (320 mg dose) with a shift of the exercise end point from pain to fatigue in seven of 17 patients. The interrelationships between propranolol daily dosage, clinical response assessed by percent reduction in anginal episodes, beta-adrenergic blockade measured by percent reduction in exercise heart rate and serum levels were examined. In general, serum levels of 30 ng/ml, when drawn 90 to 180 minutes following the last oral dose, were required to achieve a 25% or greater reduction in angina frequency. Serum levels above 30 ng/ml were similarly correlated with a 20% or greater reduction in exercise heart rate at equivalent levels of exercise. Detailed examination of different patterns of clinical response with respect to beta-blockade, serum levels and oral doses are presented.
Surgical management of large bronchial collateral arteries with pulmonary stenosis or atresia.
Authors: McGoon D C , Baird D K , Davis G D
Published: June 2012

Single or multiple large bronchial collateral arteries may provide all or some of the pulmonary arterial blood flow in patients with proximal atresia of the pulmonary artery, and even in patients with only pulmonary stenosis. At the time of corrective surgery such arteries must be ligated in order to provide favorable operating conditions, to avoid cardiac overdistention during repair, and to prevent left-to-right intrapulmonary shunting postoperatively. Their ligation and control require precise preoperative definition of their number, origin, and course, and special intraoperative methods for their exposure. Associated hypoplasia of the pulmonary arteries may be severe enough to preclude corrective operation, but these hypoplastic arteries may enlarge in response to increase of blood flow through them resulting from a surgically created shunt. Experience with 14 surgically managed cases of this type forms the basis for the report.