bluuebunny/crossref_metadata_2025 huggingface dataset:
Tape Recordings of the ECG of Active Men
Authors: HINKLE LAWRENCE E. , MEYER JEROME , STEVENS MICHAEL , CARVER SUSAN T.
Published: June 2012

The electronic and mechanical characteristics of the Holter-Avionics instruments for recording and analyzing the electrocardiogram of active men have been measured in the laboratory, and during carefully standardized 6-hour recordings of 385 active subjects. Although late model recorders have a cumulative timing error of less than 1%, the frequency response of the system is limited at both the upper and lower ends of the range, producing significant distortion of the complex. Scanning the taped data at 60 times real-time is a helpful screening procedure, but accurate analysis of records requires photographic write-out of R-R intervals with real-time scanning and analysis of all potential areas of abnormality. If records are made with subjects under constant observation and stop-watch timed, they can yield significant data on phenomena of rate, rhythm, and conduction, under a variety of circumstances and over long periods of time; but changes in the shape of the ST segment and T wave must be interpreted with great caution because of distortions produced by the recording system and by changes in position and activity.
Cardioglobulin B Content of the Blood Plasma of Newborn Infants
Authors: BENCOSME SERGIO A. , DELAHAYE D. J. , FAY J. E. , OZEN N.
Published: June 2012

A comparative study was made of the cardioglobulin B content of the plasma of 26 normal adults and 20 newborn infants with the bioassay technique described by Hajdu and Leonard. The cardioglobulin B content in the plasma of infants was significantly lower than that of adults. Heparin was used as the anticoagulant in the blood samples throughout this study. It was noted that, when heparin containing phenol as a preservative was employed, the cardioglobulin B levels were lower in both groups.
The Inheritance of Coronary Artery Anatomic Patterns in Rats
Authors: BLOOR COLIN M. , LEON ARTHUR S. , PITT BERTRAM
Published: June 2012

Coronary artery anatomic patterns were determined in 4,500 rats obtained from three unrelated inbred strains. Four basic patterns were defined based on the presence of one or two primary trunks arising from separate ostia on each side. The frequency distribution of these patterns was significantly different among the three strains. Breeding experiments showed that the patterns are polygenetically determined. Although the presence of asymmetrical patterns in each strain suggests independent determination of each side, some interaction between the factors determining the two sides was also demonstrated. These patterns may provide a model to test the hypothesis that such inherited differences in coronary patterns may be a factor in susceptibility or resistance to coronary atherogenesis and myocardial infarction.
Trends in Systolic Blood Pressure in the Thousand Aviator Cohort over a Twenty-four-Year Period
Authors: OBERMAN ALBERT , LANE NORMAN E. , HARLAN WILLIAM R. , GRAYBIEL ASHTON , MITCHELL ROBERT E.
Published: June 2012

A cohort of 1,056 normotensive, healthy, young men initially examined in 1940 at the mean age of 24 years was followed at three periodic intervals through 1964. The cohort demonstrated little rise in mean systolic blood pressure beyond age 35; a portion of this cohort showed no change of systolic blood pressure with age. If the men are classified by quintile according to systolic blood pressure in 1940, those men in the upper quintile tend to remain high; when classified by quintile in 1951, those men at the extremes maintained their relative position through 1964. Predictive utility of a systolic blood pressure may be a function of its actual level as well as the age of the individual.

Two factors further influenced the systolic blood pressure of this cohort, namely, parental longevity and gain in weight. The significant effect of parental longevity became less important relative to gain in weight as time progressed and after 1940 affected primarily those men who had gained weight.
A Later Stage of Anomalous Coronary Circulation with Origin of the Left Coronary Artery from the Pulmonary Artery
Authors: BAUE ARTHUR E. , BAUM STANLEY , BLAKEMORE WILLIAM S. , ZINSSER HARRY F.
Published: June 2012

A 45-year-old woman with angina pectoris, beginning at the age of 16 and progressing to produce incapacitation, was found to have an anomalous left coronary artery arising from the pulmonary artery. Because of the severity of symptoms and progression of disability, the anomalous artery was ligated at its origin from the pulmonary artery. Pressure in the left coronary system increased from 35/10 to 105/30 mm Hg. Since operation the patient has been relieved of her symptoms. There was no evidence of increased myocardial ischemia after ligation. This indicates that operative treatment of this anomaly can be carried out successfully in the older age group. It is also suggested that a fourth stage of progression of this anomaly occurs in which there is an exaggeration of the intercoronary communications between the right and left coronary systems. This produces such a large arteriovenous shunt that blood flow to the myocardium is again reduced, resulting in a "coronary steal syndrome."
Evaluation of the Contractile State of the Human Heart from the First Derivative of the Apexcardiogram
Authors: REALE ATTILIO
Published: June 2012

The first derivatives of the left ventricular pressure pulse (dp/dt LV) and of the apexcardiogram (Δ ACG) were recorded 73 times in 45 subjects, and the time intervals from the peak of the R wave of the electrocardiogram to the peak of the derivatives (t-dp/dt LV and t-Δ ACG) were determined under different circulatory conditions. These parameters express the duration of the development of maximum tension during isometric contraction of the ventricle. The values obtained from the left ventricular pressure pulse and from the ACG showed close correlation both at rest and after pharmacological interventions which enhanced or depressed the myocardial contractile state. During orciprenaline infusion, t-dp/dt LV and t-Δ ACG were consistently shortened, while they increased in most cases after beta-adrenergic receptor blockade.

Determination of the time to peak derivative of the ACG, a parameter so far unexplored, is proposed as a simple method of detecting changes in the myocardial contractile state in the intact human being.
Evaluation of Roentgen Cinedensitometry for Flow Measurement in Models and in the Intact Circulation
Authors: RUTISHAUSER WILHELM , SIMON HANSJÖRG , STUCKY JEAN PAUL , SCHAD NIKLAUS , NOSEDA GIORGIO , WELLAUER JOSEF
Published: June 2012

The flow of blood in vitro and in the carotid artery of the dog was calculated by a new cinedensitometric technique and compared with the flow as measured simultaneously by graduated cylinder and stopwatch. Cineangiographic films were projected onto a frosted screen and the light intensity was measured at two neighboring cross sections of the vessel in question. The passage of the contrast medium yielded a pair of indicator-dilution curves of which the difference in mean transit time was calculated. The distance between the cross sections and the diameter of the vessel was measured with the aid of x-ray-dense scales. The flow through the vessel was calculated as the product of cross-sectional area and mean velocity.

The correlation coefficient between the volumetric flow and the flow as found by cinedensitometry was 0.976 in vitro and 0.946 in the intact dog with no systematic deviation from the line of identity. The method enables the blood flow in the intact circulation to be calculated in milliliters per second in any vessel that can be clearly visualized by cineangiocardiography.
Myocardial Biopsy in Dogs
Authors: ECKNER FRIEDRICH A. O. , THAEMERT JONA C. , MOULDER PETER V. , BLACKSTONE EUGENE H.
Published: June 2012

Full-thickness biopsies of ventricular dog myocardium, beating and in arrest, have been studied by conventional fixation (immersion in fixative solution), by the use of cryostat sections thawed on slides, and by freeze drying of tissue blocks. Three types of artifacts were found and could be related (1) to cutting into the beating heart, (2) to thawing of frozen sections on slides, and (3) to the failure of fixative solutions to immobilize still reactive myocardium immediately. The method described yields a biopsy specimen of sufficient diameter to delineate the cutting artifacts. For histological preparation freeze drying appears to be the method of choice.
The Electrocardiophone
Authors: GREEN HENRY L.
Published: June 2012

The electrocardiophone is a new, miniaturized, self-contained inexpensive device for the bedside recognition of cardiac arrhythmias. It converts electrocardiographic signals to frequency-modulated audiotone patterns that the physician can readily learn to recognize. It is most useful in situations calling for rapid diagnosis, such as cardiac resuscitation and the monitoring of patients in transit. It is helpful in timing heart sounds and murmurs, and may prove to have practical value in the differential diagnosis of pacemaker failure as well.
Vectorcardiographic Diagnosis of Left Ventricular Hypertrophy
Authors: ROMHILT DONALD W. , GREENFIELD JOSEPH C. , ESTES E. HARVEY
Published: June 2012

The vectorcardiographic diagnosis of left ventricular hypertrophy, using the Frank lead system, was evaluated in 93 autopsied male patients (70 with hypertrophy of the left ventricle and 23 without such hypertrophy). The criterion of the maximal QRS magnitude in the transverse plane greater than 2.2 mv below the age of 50 years and 1.8 mv at the age of 50 or more was positive in 61% of hypertrophied hearts and negative for all the nonhypertrophied hearts. The criterion of the T loop vector greater than H°-70° in the transverse plane was positive in 82% of 49 hypertrophied hearts and positive in one (7%) of 15 normal hearts for which the T loop was available.

The maximal QRS magnitudes in the frontal and sagittal planes had too low a sensitivity to be of value while the angles of the maximal QRS vector in the transverse and sagittal planes was too nonspecific to be useful.

By combining the QRS magnitude and the T loop vector in the transverse plane, the diagnosis of left ventricular hypertrophy was made in 90% of 49 hypertrophied hearts for which the T loop was available.
Recognition and Significance of Intraventricular Block due to Myocardial Infarction (Peri-infarction Block)
Authors: SHADAKSHARAPPA K. S. , KALBFLEISCH J. M. , CONRAD L. L. , SARKAR N. K.
Published: June 2012

Evidence of peri-infarction block was found in 39% of the electrocardiograms of 1,938 patients with definite evidence of myocardial infarction. It most commonly occurred acutely or within several days following infarction and was more common with recurrent infarction. Peri-infarction block infrequently disappeared and was associated with higher values for serum glutamic-oxalacetic transaminase and a greater mortality in the first year following myocardial infarction. There was no autopsy correlation of peri-infarction block and ventricular aneurysmal formation.

The term "peri-infarction block" is appropriate only when abnormal intraventricular conduction occurs in association with definite electrocardiographic evidence of myocardial infarction.
Amiloride
Authors: BULL MARCIA B. , LARAGH JOHN H.
Published: June 2012

Amiloride, a new, well-tolerated oral natriuretic and mild diuretic agent, has been evaluated alone and in combination with other diuretics. Its remarkable ability to promote retention rather than loss of potassium makes it a useful adjunct in the management of even the most severe edematous states. It also retards the alkalosis produced by certain of the stronger diuretics by blocking hydrogen secretion and promoting bicarbonate loss. In addition to being a valuable adjunctive agent, the compound may be useful alone because of the advantages inherent in steady, sustained natriuretic therapy with a mild diuresis as opposed to incurring precipitous alterations in fluid and electrolyte balance with the intermittent use of more potent agents. In certain patients it was mildly antihypertensive.

Amiloride produced marked increases in aldosterone secretion with lesser rises in plasma renin. The adrenal stimulation therefore appeared to result from both potassium retention and renin activation consequent to natriuresis.

The compound appears to act primarily in the distal nephron, blocking both sodium-hydrogen exchange and sodium-potassium exchange. Like triamterene, but unlike spirolactone, amiloride has the characteristics of a noncompetitive inhibitor of aldosteronedirected sodium and potassium transport. Because of this, it may be expected to produce more predictable effects than spirolactone and at least in certain instances to be more powerful. It may also be preferable to spirolactone for the acute control of derangements in potassium balance because of its more rapid onset and disappearance of action.

No significant toxicity was encountered; however, serum potassium values should be carefully monitored, especially in situations involving impaired renal function.
Atrial Fibrillation Produced by Atrial Stimulation
Authors: HAFT JACOB I. , LAU SUN H. , STEIN EMANUEL , KOSOWSKY BERNARD D. , DAMATO ANTHONY N.
Published: June 2012

Twenty-six episodes of atrial fibrillation and flutter-fibrillation, each lasting less than 23 sec, were recorded in three normal subjects during atrial pacing studies. The cause of these atrial arrhythmias was determined to be the result of stimulation within the atrial vulnerable period.
Drug Therapy of Dissecting Aortic Aneurysms
Authors: LINDSAY JOSEPH , HURST J. WILLIS
Published: June 2012

The records of 56 patients with proved acute aortic dissection were studied for factors bearing on the applicability of vigorous drug therapy to reduce arterial pressure. Fourteen patients had an arterial pressure of 120 mm Hg systolic or less. Fifteen additional patients had evidence of occlusion of a major branch of the aorta. More than half of the 56 patients, therefore, could not have received antihypertensive drugs.

The presence of a contraindication to drug therapy marked a patient for an early death. All 29 died within 2 weeks. Twelve of the 27 in whom no contraindications to drug therapy were observed survived more than 2 weeks and six survived more than a year even though none were placed on a vigorous antihypertensive regimen.

Assessment of the efficacy of drug therapy of dissecting aortic aneurysm should take into account these facets of the natural history.
Effects of Isoproterenol on the Pulmonary Blood Volume in Patients with Valvular Heart Disease and Primary Myocardial Disease
Authors: SCHREINER BERNARD F. , MURPHY GERALD W. , JAMES DOUGLAS H. , YU PAUL N.
Published: June 2012

The effects of intravenous isoproterenol upon the pressure-flow-volume relationships in the pulmonary vascular bed were studied in 34 patients and one normal subject during simultaneous right and transseptal left heart catheterization. In five patients with primary myocardial disease and in one normal subject, active pulmonary vasodilation was demonstrated by a significant increase in pulmonary blood volume (PBV) and a concomitant fall in pulmonary vascular distending pressure (P
D
). Infusion of the drug into 18 patients with mitral stenosis resulted in a concordant rise in PBV and PD, strongly suggesting passive distention of the pulmonary vascular bed. In contrast to the responses of these two groups of patients, isoproterenol infusion into 11 patients with aortic valve disease failed to change the PBV, but caused a significant decrease in P
D
.

It is concluded that the response of different groups of patients to isoproterenol cannot be explained by a single mechanism. Multiple actions of the drug must be considered, including active pulmonary vasodilation, a positive inotropic action upon the heart, and bronchomotor effects.
Spontaneous Aortic Cusp Rupture Associated with Valvular Myxomatous Transformation
Authors: O'BRIEN KEVIN P. , HITCHCOCK GEORGE C. , BARRATT-BOYES BRIAN G. , LOWE JAMES B.
Published: June 2012

Two adult male patients are presented with sudden onset of aortic incompetence secondary to rupture of an aortic valve cusp. Histological examination of these leaflets revealed myxomatous changes. Operation was undertaken on both patients, and an aortic homograft valve was inserted in each with a very satisfactory result. The relationship between medionecrosis of the aorta and myxomatous valvular transformation is discussed.
Transposition of the Great Arteries
Authors: PLAUTH W. H. , NADAS A. S. , BERNHARD W. F. , GROSS R. E.
Published: June 2012

Experience with 74 consecutive patients with transposition of the great arteries treated by palliative methods at the Children's Hospital Medical Center in Boston from June 1950 to September 1966 forms the basis for this report. Four palliative techniques were considered in detail. The specific palliative approach suggested depended on the anatomy and physiology in the individual case. Atrial septal defect creation was used largely for patients with an intact ventricular septum to improve arterial saturation, vent the left atrium, and prevent development of pulmonary vascular obstructive changes. Pulmonary artery banding was the procedure used mainly for infants with large ventricular septal defect, adequate mixing, and pulmonary arterial hypertension. The combined operation was performed on infants with ventricular defect in whom arterial-venous mixing was less than optimal through a relatively small ventricular septal defect. Arterial shunt operations were used for cyanotic infants, not in congestive failure, with ventricular septal defect and severe pulmonic stenosis.

The authors recommend palliative surgery in the neonatal period for all patients with transposition of the great arteries, except for the few with type IIA lesions who have just the optimal amount of arterial saturation and absence of congestive heart failure. At present at least an 84% survival rate can be expected from the palliative surgical procedures even in the critically ill infant in the first days of life.
Observation and Simulation of the Circulation, Acid-Base Balance, and Response to CO
2
in Cheyne-Stokes Respiration
Authors: LANGE RAMON L. , BOTTICELLI JAMES T. , CARLISLE ROBERT P. , TSAGARIS THEOFILOS J. , HORGAN JAMES D.
Published: June 2012

Circulatory, chemical, and ventilatory response factors in Cheyne-Stokes respiration (CSR) were studied by experimental procedures and by mathematical analysis. Hemodynamic, ventilatory, and blood gas patterns in 16 patients with heart disease and CSR (group A) and 16 patients with congestive heart failure (CHF) without CSR (group B) were compared. CO
2
and oxygen were administered to group A. The phenomena exhibited by patients with CSR were simulated by a mathematical model.

The following conclusions were drawn: (1) Reduced blood flow and respiratory alkalosis were similar in both groups; (2) circulation times, lung to artery, were 29 sec greater than normal in patients with CSR but only 8 sec greater than normal in group B patients; (3) the abnormal CO
2
response in CSR, a reduction in threshold and sensitivity, was similar to that in CHF, suggesting that abnormal respiratory mechanics were responsible; (4) mathematical simulation of CSR was possible by appropriate prolongation of circulation time alone; the CO
2
response (reduction in threshold and sensitivity) had no significant effect on stability; (5) damping of oscillatory ventilation by CO
2
inhalation could be efficiently simulated; (6) CSR with cycle periods less than 50 sec suggests increased neural or chemoreceptor excitability, anemia, or hypoxemia as contributory factors, whereas longer periods suggest primary circulatory factors.
Polyethylene Catheter Embolism
Authors: WELLMANN KLAUS F. , REINHARD ARTHUR , SALAZAR EDGARDO P.
Published: June 2012

A 62-year-old man died from tricuspid monilial endocarditis and systemic candidiasis associated with embolization to the right heart of a 36-cm fragment of one polyethylene catheter received in the venous system approximately one year earlier. Thirty-six additional cases of catheter embolism are reviewed and tabulated. In 17 of the 37 patients the catheter fragment had reached the right side of the heart, and in eight, a branch of the pulmonary artery. In six of 13 patients who died, catheter embolism was the exclusive or a major contributory cause of death. Measures designed to prevent the breakage and embolization of polyethylene tubes and to facilitate their retrieval in case of loss are discussed. If a catheter fragment has been lost into the venous system, it should be located and removed at once.

Monilial endocarditis and systemic candidiasis are briefly reviewed. The reported case is the first in which these entities have been associated with catheter embolism to the heart, and the fourth in which monilial endocarditis affected the tricuspid valve.
Muscle Blood Flow During Exercise in Intermittent Claudication
Authors: TØNNESEN K. H.
Published: June 2012

Pathophysiological considerations predict that exercise blood flows at comparable work loads must always be reduced in claudicants in comparison to normal subjects. The present study verified that the exercise blood flow determined by
133
xenon clearance measurements in the gastrocnemius muscle in claudicants and in a control group differed widely.

As expected, a statistically significant correlation was found between the first flow by plethysmography and the maximal exercise blood flow determined by the
133
xenon clearance technique in the patients and for the whole material (but not for the control group alone). The exercise blood flow determined by
133
xenon clearance in the claudicants was statistically significantly correlated to the walking distance, measured on a treadmill, while the postexercise blood flow as measured by plethysmography was not. This finding establishes the concept, that the
133
xenon clearance technique can be applied in quantitating the degree of arterial insufficiency.
The Paradox of Beta-Adrenergic Blockade in Hypertension
Authors: FROHLICH EDWARD D. , TARAZI ROBERT C. , DUSTAN HARRIET P. , PAGE IRVINE H.
Published: June 2012

The effects of long-term treatment with propranolol, a beta-adrenergic blocking drug, were determined in 19 hypertensive patients (five with renal arterial disease, two with renal parenchymal disease, and 12 with essential hypertension) whose vascular disease was of mild to moderate severity. The drug reduced arterial pressure in 16 patients during 32 weeks of treatment (average); daily dose was 180 mg (average). No side effects required discontinuance of treatment. Orthostatic hypotension did not occur, an unusual finding for an antihypertensive drug which acts to inhibit autonomic neural function. In seven patients, hemodynamic studies, performed during treatment (after 10 months, average), confirmed reduction of arterial pressure and heart rate, and demonstrated associated diminution of cardiac output and increased peripheral resistance.
Diphenylhydantoin Prevention of Arrhythmias in the Digitalis-Sensitized Dog after Direct-Current Cardioversion
Authors: HELFANT RICHARD H. , SCHERLAG BENJAMIN J. , DAMATO ANTHONY N.
Published: June 2012

The ability of diphenylhydantoin to prevent arrhythmias induced by synchronized direct current shocks after digitalis sensitization was evaluated. In the control state, an average of 155 watt-seconds was required to produce ventricular tachycardia. Immediately after recovery from digitalis toxicity, an average of 23 watt-seconds produced ventricular tachycardia. The administration of diphenylhydantoin at this time immediately increased the threshold required for ventricular tachycardia to an average of 363 watt-seconds. In eight studies, diphenylhydantoin was given during cardioversion-induced ventricular tachycardia and converted all cases to regular sinus rhythm. These findings indicate that diphenylhydantoin may be of prophylactic value prior to direct current cardioversion in a digitalized patient. Conversely, diphenylhydantoin would also be useful in the management of ectopic beats that may occur in digitalized patients after cardioversion.
Relationship of Right Bundle-Branch Block and Marked Left Axis Deviation (with Left Parietal or Peri-infarction Block) to Complete Heart Block and Syncope
Authors: LASSER RICHARD P. , HAFT JACOB I. , FRIEDBERG CHARLES K.
Published: June 2012

The pattern of complete right bundle-branch block (RBBB) combined with abnormal left axis deviation is shown to be the predominant conduction abnormality during orthograde (antegrade) conduction in patients who have experienced transient or permanent complete heart block (59% of a series of 44 patients). Sequential records on the same patient are presented showing progressive development of the complete pattern from left parietal and peri-infarction block alone and also from RBBB with normal axis deviation. Underlying abnormality is a partial bilateral bundle-branch block, that is, complete RBBB and involvement of the anterior-superior subdivision of the left bundle. The incidence of this pattern in 5,500 consecutive hospital records was 1%. Of these, 10% manifested complete heart block. It is suggested that a history of syncope or dizziness in a patient with the above pattern may denote that episodes of transient heart block have occurred.
The In Vivo Determination of Left Ventricular Volume
Authors: HUGENHOLTZ PAUL G. , WAGNER HENRY R. , SANDLER HAROLD
Published: June 2012

End-diastolic volumes, stroke volumes, and ejection fractions determined in quick succession by the fiberoptic indicator-dilution technique and the angiocardiographic method were compared in 63 patients with various disorders, aged 6 weeks to 58 years. The calibration methods are discussed in detail.

Good agreement was found (r=0.965) although end-diastolic volume by the fiberoptic-indicator method (FO) (mean, 106.3 ml/m
2
) consistently exceeded enddiastolic volume by the angiocardiographic method (A) (92.5 ml/m
2
). Variations in injection techniques, the absolute size of the volume (range, 31.0 to 478.5 ml/m
2
), and heart rate (from 55 to 179 beats/min) did not influence this correspondence significantly.

Stroke volumes, ejection fractions, and end-systolic volumes were compared in 41 patients with nonregurgitant lesions. The correlation coefficients are 0.808, 0.824, and 0.950, respectively.

These results show better agreement than was previously suggested by workers utilizing other indicator-dilution systems. Reasons for this finding, such as the fact that studies were carried out in quick succession in the same patients, the advantage of indocyanine green over other indicators, the characteristics of the fiberoptic sampling system, the adequacy of mixing in the human left ventricle, and the errors inherent in the angiocardiographic method are discussed. Since agreement existed over a wide range of volumes, a set of regression equations was calculated that permitted the interchange of stroke volume, ejection fraction, and end-systolic and end-diastolic volumes in situations where one technique is favored over the other. Thus, for end-diastolic volume by angiocardiography, EDV
A
=0.785 EDV
FO
+ 10.6 (in ml/m
2
).
Effect of Propranolol on Elevated Arterial Blood Pressure
Authors: RICHARDSON DAVID W. , FREUND JACK , GEAR ARTHUR S. , MAUCK H. PAGE , PRESTON LESTER W.
Published: June 2012

Nineteen patients with moderately severe arterial hypertension received propranolol (120 mg daily), or chlorthalidone (100 mg daily), both medications together, and placebos in a double-blind crossover trial. Each treatment was given for 5 weeks; blood pressure was measured at weekly intervals. Propranolol alone reduced arterial pressure by 9/8 mm Hg, a statistically insignificant change. Use of chlorthalidone alone was accompanied by an average reduction in arterial blood pressure of 23/9 mm Hg. Both drugs together lowered blood pressure by 33/15 mm Hg. Heart rate was lower in regimens including propranolol; body weight and serum potassium and chloride concentration were lower and blood urea nitrogen and serum creatinine were higher in regimens containing chlorthalidone. Propranolol, in the dose given, is a less effective hypotensive drug than is chlorthalidone.
Effects of Physical Training in Dogs with Coronary Artery Ligation
Authors: KAPLINSKY ELIEZER , HOOD WILLIAM B. , McCARTHY BRIAN , McCOMBS H. LOUIS , LOWN BERNARD
Published: June 2012

This experiment was designed to determine whether physical conditioning can be achieved in the presence of acute myocardial infarction and whether such an exercise program is harmful. For this purpose the effects of a 5-weeks' treadmill-exercise program and inactivity were compared in two groups of dogs in which acute myocardial infarction was produced by coronary artery ligation.

The exercised group of animals tolerated the training program well, and neither arrhythmia nor sudden death occurred. At the end of the training program the exercised group of animals displayed the characteristic changes of physical conditioning, namely, reduction in exercise heart rate, cardiac output, and blood lactate levels; rise in circulating epinephrine levels with exercise was also suppressed by conditioning. Postmortem examination revealed neither ventricular dilatation nor aneurysm formation.
The Anatomic Atrial Connections Between Sinus and A-V Node
Authors: MERIDETH JOHN , TITUS JACK L.
Published: June 2012

The morphology of the sinus and atrioventricular (A-V) nodes of human hearts was studied and connecting pathways between these nodes were sought. The cells of both nodes differed from ordinary atrial and ventricular myocardium in respect to size, shape, number, and arrangement of cytoplasmic organelles. Using the criteria of fiber-to-fiber connection, shown by means of serial histological sectioning, this study confirmed previous reports of three pathways between the sinus and A-V nodes in the human heart. It was not required that these pathways be composed of classic Purkinje-type fibers, though many of the fibers did possess some of the features of Purkinje fibers. While recent evidence reveals that specialized atrial pathways do demonstrate increased conduction velocity, their prime functional significance may be in the facilitation of orderly atrial depolarization, the maintenance of sinus node control of ventricular depolarization under various physiological conditions, and the provision of an orderly "input" into the A-V node, a tissue generally acknowledged to have a low margin of safety.
The Frontal Plane Vectorcardiogram in Old Inferior Myocardial Infarction
Authors: YOUNG ELIOT , WILLIAMS CONGER
Published: June 2012

The early part of the frontal plane QRS loop (Frank lead system) was analyzed in 100 consecutive patients with an old inferior myocardial infarction. In order to be included in this study, all cases had to fulfill, at some time, Myers' classical ECG criteria for the diagnosis. The vectorcardiogram was made months to years after the patient's original acute episode.

Several scalar and planar parameters, pertaining to these frontal plane early QRS vectors, were analyzed. As a result of this analysis and in order to prevent overlap with values found in 315 normal control subjects, VCG criteria, based on the interrelationships of several of these parameters, were proposed for the diagnosis of old inferior myocardial infarction. Pitfalls in the use of only scalar or planar analyses were pointed out.

In 90 of the 100 cases the diagnosis was made on the basis of the proposed VCG criteria. However, the ECG made at the same time fulfilled Myers' or Goldberger's classical criteria in only 42 of the 100 cases. All cases diagnosed from the ECG were also diagnosed from the VCG.
Indirect Systolic Pressures and Pulse Waves in Arterial Occlusive Disease of the Lower Extremities
Authors: CARTER STEFAN A.
Published: June 2012

Measurements were carried out in 146 limbs with angiographically documented arterial occlusive disease (AOD) and in 85 limbs without AOD. Ankle systolic pressure (AP) was equal to or higher than brachial systolic pressure in limbs without AOD. It was below 82% of the brachial in all limbs with complete occlusion, usually below 50% in those with multiple occlusions, and above 50% in limbs with single block. AP was below normal in 19 of 25 limbs with severe and in five of nine with mild stenosis. All limbs with complete occlusion and 14 of 16 with stenosis had abnormal pressures in the thigh. The foot-to-peak time (CT) and the width of pulse waves at half amplitude (WD) were related to heart rate in normal limbs. Considering the heart rate, the majority of limbs with AOD had abnormally prolonged CT and WD. Normal pressures and pulse waves were found together in only two limbs with stenosis and symptoms. The findings indicate that pressures and pulse waves provide a sensitive method for diagnosis and follow-up of patients with AOD.
Secondary Left Ventricular Endocardial Fibroelastosis Following Mitral Valve Replacement
Authors: ROBERTS WILLIAM C. , MORROW ANDREW G.
Published: June 2012

Secondary endocardial fibrosis of variable severity was observed in the left ventricle in 13 of 16 patients after mitral valve replacement. Similar lesions were not observed in any of 20 patients who died in the late postoperative period after isolated aortic valve replacement. The left ventricular endocardial thickening is believed to be the result of turbulent flow, produced in the left ventricle by the caged ball within it. Severe impairment of cardiac function appeared to result from the process in two of the 13 patients: each developed intractable and ultimately fatal cardiac failure several months after double valve replacement, and the extensive endocardial thickening was the only anatomical cause for failure in both patients. Thus, secondary left ventricular endocardial fibrosis appears to be another, although uncommon, cause of cardiac failure in the late postoperative period after replacement of the mitral valve with a cagedball prosthesis.
Severe Mitral Regurgitation Following Acute Myocardial Infarction and Ruptured Papillary Muscle
Authors: MORROW ANDREW G. , COHEN LAWRENCE S. , ROBERTS WILLIAM C. , BRAUNWALD NINA S. , BRAUNWALD EUGENE
Published: June 2012

The results of operative treatment are described in four patients who sustained myocardial infarctions and in whom ruptured left ventricular papillary muscles caused severe mitral regurgitation. All were men between 51 and 69 years of age, and the intervals between myocardial infarction and operation were 3 to 15 months. Each patient manifested severe congestive heart failure. All were in sinus rhythm and had an apical holosystolic murmur and an atrial gallop sound. Three of the four had severe pulmonary hypertension (60 to 80 mm Hg systolic), grossly elevated mean left atrial pressure, and v waves 37 to 45 mm Hg. In all the cardiac index was abnormally low (average 1.8 L/min/m2). In all four patients the mitral valve was replaced with a 2M Starr-Edwards prosthesis. In two of the excised valves, one head of the posterior papillary muscle was infarcted and had ruptured, and in the other two the anterior papillary muscle was similarly involved. All patients survived, and all have derived distinct symptomatic improvement at intervals of 7 to 16 months. Hemodynamic studies were repeated 11 months postoperatively in one patient; although he is asymptomatic and the cardiac index is increased, intracardiac pressures remain elevated, and residual impairment of left ventricular function is evident. In a second patient the left ventricle apparently retained satisfactory functional capacity for symptomatic benefit has been paralleled by striking reductions in pulmonary arterial and left atrial pressures measured six months postoperatively.
Effects of Cardiopulmonary Bypass on the Phagocytic and Bactericidal Capacities of Polymorphonuclear Leukocytes
Authors: KAPLAN EDWARD L. , CASTANEDA ALDO R. , AYOUB ELIA M. , QUIE PAUL G.
Published: June 2012

Studies on phagocytosis, intracellular digestion, and bactericidal capacity of polymorphonuclear leukocytes from patients undergoing cardiac surgery requiring a pump oxygenator reveal no significant abnormalities in these separate and distinct events. Furthermore, these cells reveal no differences from normal polymorphonuclear leukocytes in the morphological changes following phagocytosis. Polymorphonuclear leukocytes from heparinized fresh blood used for transfusions also demonstrated normal function. It is doubtful if impaired function of polymorphonuclear leukocytes from these patients contributes significantly to their apparently increased susceptibility to bacterial infection.
Restoration of Sinus Rhythm After Mitral Valve Replacement
Authors: FISHER R. DARRYL , MASON DEAN T. , MORROW ANDREW G.
Published: June 2012

Factors relating to the successful and sustained restoration of sinus rhythm were examined in 100 patients following mitral valve replacement. Of the 30 patients who established sinus rhythm in the postoperative period, 24 were in sinus rhythm before operation and 6 converted spontaneously. All 30 had normal mean left atrial pressure at rest and only mild or moderate roentgenographic evidence of left atrial enlargement. All 70 patients with atrial fibrillation following valve replacement had been in atrial fibrillation preoperatively; in 24 of them cardioversion was not attempted. In the other 46 patients, electrical conversion was attempted on one or more occasions; in 31 (68%), sinus rhythm was maintained for at least 24 hours, but only 9 were in sinus rhythm 18 months later. Two additional patients maintained sinus rhythm on a long-term basis after conversion with maintenance quinidine.

Among the 15 patients refractory to countershock, the mean left atrial pressure averaged 11.1 ± 1.3 mm Hg, and among the 22 patients who reverted to atrial fibrillation it was 13.3 ± 0.9 mm Hg. In contrast, mean left atrial pressure was significantly less (8.1 ± 0.9 mm Hg) and left atrial enlargement only moderate in the patients who maintained sinus rhythm after cardioversion. Importantly, all patients with mean left atrial pressures greater than 12 mm Hg and/or marked left atrial enlargement were refractory to countershock or relapsed to atrial fibrillation, while 64% of patients with normal mean left atrial pressures sures and only moderate left atrial enlargement maintained sinus rhythm permanently. Right atrial pressures were normal in both groups.

Thus, elevated left atrial pressure and increased left atrial size both militate against the chronic establishment of sinus rhythm. This study indicates that following mitral valve replacement permanent maintenance of sinus rhythm can be anticipated in about two of three patients in whom the mean left atrial pressure is normal and in whom left atrial enlargement is only moderate.
Pulmonary Arteriovenous Admixture in Cardiac Surgical Patients
Authors: ELTRINGHAM W. K. , SCHRÖDER R. , JENNY M. , MATLOFF J. M. , ZOLLINGER R. M.
Published: June 2012

Patients undergoing cardiac surgery with cardiopulmonary bypass for mitral insufficiency develop significant hypoxemia after surgery. This is due mostly to true shunt, but there is a significant contribution due to ventilation-perfusion abnormalities. The condition persists for eight to ten days but is reversible. Breathing 100% oxygen in the postoperative period reduced cardiac output and pulmonary artery pressure and increased arteriovenous oxygen content differences. A redistribution of pulmonary blood flow is suggested by these findings, and accordingly the value for true shunt may vary with changing inspired oxygen concentrations.
Quantitative Studies of Extracoronary Blood Flow After Double Internal Mammary Artery Implantation
Authors: CRIOLLOS ROSENDO L. , AL-SHAMMA ABDUL M. , ROE BENSON B.
Published: June 2012

A technique for implanting both internal mammary arteries into left ventricular myocardial walls is described. Direct measurement of total and collateral coronary blood flow was made in terminal experiments six months after surgical implantation. The effluent from the right heart before and after occlusion of normal coronary arterial perfusion during extracorporeal circulation closely reflects total and collateral blood flow. An average flow of 70 ml/min, representnig 25% of normal coronary blood flow, was measured from double internal mammary artery implants plants in the ischemic canine heart. Lower flow rates (18 ml/min) were measured from similar double mammary artery implants into nonischemic hearts. Effective tissue perfusion from collateral pathways was demonstrated by metabolic studies which excluded arterioyenous shunting. The results of radiographic and microscopic examination were consistent with measured blood flows in each animal.
A New Operation for Repairing Aortic Arch Atresia in Infancy
Authors: SIRAK HOWARD D. , RESSALLAT MEHDI , HOSIER DON M. , DELORIMIER ALFRED A.
Published: June 2012

Aortic arch atresia is a comparatively rare congenital anomaly that commonly produces heart failure and death in early infancy. A new operative procedure is described which is applicable to type I, where the atresia lies distal to the left subclavian artery. It provides a lumen that is equal to the descending thoracic aorta by using the conjoined orifices of the left subclavian and common carotid arteries for anastomosis to the distal thoracic aorta. The chief advantage of this method is that it not only provides a vascular bridge with a lumen equal to the distal thoracic aorta, but also assures normal growth potential.
Hemodynamic Response to Discoid Mitral Valve Replacement
Authors: MATLOFF JACK M. , DALEN JAMES E. , DEXTER LEWIS , HARKEN DWIGHT E.
Published: June 2012

Hemodynamic studies were performed before and daily for 7 to 10 days after mitral valve replacement with a discoid prosthesis in 15 patients.

Left atrial mean pressure fell from a mean of 27.5 mm Hg before surgery to normal levels (mean 11 mm Hg) within 24 hours of surgery. Cardiac index reached normal levels (mean 2.97 L/min/m
2
) within 48 hours of valve replacement, and remained in the normal range throughout the early postoperative period in 12 of the 15 patients. The association of normal left atrial pressure and cardiac output in response to the increased metabolic demands of the postoperative period has not been reported with caged-ball mitral valve replacement.

Pulmonary artery mean pressure and pulmonary vascular resistance showed a sharp decrease toward normal in the early postoperative period. In seven patients with systemic pulmonary hypertension, pulmonary artery mean pressure decreased from 72 mm Hg before surgery to 38 mm Hg at 7 to 10 days.

The observed hemodynamic findings in these patients are consistent with experimental evidence that discoid mitral prostheses offer less resistance to blood flow than caged-ball mitral prostheses.
Fiberoptic-Dye Dilution Method for Measurement of Cardiac Output
Authors: WAGNER HENRY R. , GAMBLE WALTER J. , ALBERS WILLIAM H. , HUGENHOLTZ PAUL G.
Published: June 2012

A new method for the measurement of cardiac output has been tested in 69 patients undergoing catheterization of the right and left sides of the heart. It is based on the recently described fiberoptic hemoreflection method. In order to verify the validity of these measurements, correlations with stroke indices determined by the Fick principle and by biplane angiocardiography were also carried out. Details of the biplane angiocardiographic technique and of the fiberoptic calibration methods are given.

Comparisons were carried out in 37 instances between the results after injections in the pulmonary artery (mean stroke index, 40.8 ml/m
2
) and in the left ventricle (mean, 42.9 ml/m
2
). Good agreement was found, r=0.930, with a mean difference of 2.1 ml/m
2
.

Stroke indices by fiberoptics (FO) were first compared with those obtained by the standard Fick method. In 100 determinations the mean stroke index by FO was 45.7 ml/m
2
, and Fick 49.0 ml/m
2
(r=0.859; confidence limits, 0.77<
p
<0.93). Correlations were then carried out in 42 instances between stroke index by FO (mean, 49.1 ml/m
2
) and by angiocardiography (mean, 48.2 ml/m
2
, r=0.799; confidence limits, 0.65<
p
<0.90). Various factors influencing the angiocardiographic method for determining stroke index are discussed.

It is concluded, that the fiberoptic-indicator dilution method is an accurate system to determine cardiac output regardless of the site of injection (LV or PA). Its versatility, the lack of need for blood withdrawal, and the generally satisfactory agreement with angiocardiographic or standard Fick method recommend its general application when cardiac output determinations are required during the process of cardiac catheterization, provided sampling is carried out in the aorta.
Ventricular Septal Defect of Atrioventricular Canal Type with Straddling Right Atrioventricular Valve and Mitral Valve Deformity
Authors: RASTELLI G. C. , ONGLEY PATRICK A. , TITUS JACK L.
Published: June 2012

At the Mayo Clinic, four patients were seen in whom a ventricular septal defect (VSD) of the atrioventricular (A-V) canal type was associated with an angle of nearly 90° between the intact atrial septum and the ventricular septum. The right atrium overrode the ventricular septum and communicated with both ventricles. A complex, straddling right A-V valve had some attachments in the left ventricle and resembled the common A-V valve of persistent common A-V canal. In three of the patients, a congenital mitral valve deformity also existed. Mild cyanosis probably is not a contraindication to surgical repair in such patients because right atrial blood may enter the left ventricle directly.
Chapter 5: Arrhythmias
Authors: MCINTOSH HENRY D.
Published: June 2012

Ventricular fibrillation was the most common major arrhythmia reported, having occurred in 59 of 12,367 studies (0.48%). The age-related incidence of the complication is shown in figure 1 and the relative incidence was as follows:

[see table in the PDF file]

The relative incidence may reflect the severity of the heart disease since most of the infants studied were critically ill. Twelve of the 13 patients less than 60 days old in whom ventricular fibrillation developed had coarctation tion of the aorta, aortic stenosis, hypoplasia of the left heart, or mitral atresia. Patients with these diagnoses represented approximately 10% of all patients under the age of 60 days who were studied.
Myocardial Blood Flow in Man Measured by a Coincidence Counting System and a Single Bolus of
84
Ribidium Chloride
Authors: KNOEBEL SUZANNE B. , MCHENRY PAUL L. , ROBERTS DAVID , STEIN LEON
Published: June 2012

Using a coincidence counting system and a single bolus injection of
84
RbCl, the effect of sublingual nitroglycerin (0.6 mg) on myocardial blood flow (MBF) in normal human subjects was studied. Concomitant pressure time per minute work of the heart was calculated as the product of heart rate, systolic mean pressure, and systolic ejection period. Seventeen subjects were studied. In seven, repeat measurements were made 3 minutes after administration of nitroglycerin and in 10 subjects 10 minutes after the drug was given.

There was no predictable direction of change in myocardial blood flow, seven subjects showing an increase and 10 subjects a decrease. There was a highly significant correlation (
P
<0.001), however, between the changed in myocardial blood flow and concomitant pressure time. It is concluded that sublingual nitroglycerin does not a priori increase myocardial blood flow in normal man at 3 or 10 minutes; rather, the changes may be related to changes in myocardial oxygen requirements. It would appear, thus, that nitroglycerin does not alter the autoregulatory vessels of the heart.