http://cardiology.org/recentpapers/sumetgl02.pdf

Association Task Force on Practice Guidelines (Committee to Update the 1997 Exercise Testing Guidelines)

The congenital anomaly in which the left coronary artery arises from the main pulmonary artery is infrequent, but lethal, and since it can be alleviated surgically, its recognition and hemodynamic consequences are important. On the basis of 140 reported cases and our seven cases, it seems to present in one of four ways: (1) in infancy with angina-like symptoms or as cardiomyopathy, and later (2) as mitral insufficiency, (3) continuous murmur, or in adults (4) by sudden death. Visualization of the coronary arteries provides the definitive diagnosis, and the problem is the selection for this procedure. The electrocardiogram, the most helpful laboratory aid, is diagnostic of infarction in 80% of the infant group; in the remainder other forms of cardiomyopathy may be confused. Although blood flows directly into the pulmonary artery in the majority of cases, it flows in the reverse direction in a few and this must be determined preoperatively. Some unanswered questions are the subject of discussion: Why the ma...

Anomalous origin of the left coronary artery from the pulmonary trunk. Its clinical spectrum, pathology, and pathophysiology, based on a review of 140 cases with seven further cases

Major anomalies of coronary arterial origin seen in adulthood.

Pediatric Sports Medicine for the Practitioner

Normal and anomalous coronary arteries: definitions and classification.

Three cases of anomalous pulmonary venous return to the inferior vena cava are presented and 18 previously reported cases are also analyzed. The clinical, radiographic, circulatory and pulmonary function, and anatomic features are carefully detailed. In particular, associated vascular and bronchial anomalies in the lungs were found by preparation of vinylite casts of the pulmonary vessels and bronchial casts; they are of great significance in planning and executing surgical therapy.

Bronchial and Arterial Anomalies with Drainage of the Right Lung into the Inferior Vena Cava

Since children with aortic valve stenosis, who are at risk of syncope or sudden death, cannot be identified by the resting electrocardiogram or vectorcardiogram, the exercise electrocardiogram was evaluated and compared with the hemodynamic data obtained during cardiac catheterization. Telemetered exercise electrocardiograms were obtained in 31 children, ages 8 to 18 years, with aortic valve stenosis and in 25 normal children of comparable age. Electrocardiographic leads V1, V5, and V6 were obtained prior to, during, and following exercise on a variable resistance bicycle ergometer. Subjects pedalled until a heart rate of 170 per minute or greater was attained and maintained for at least 2 minutes. An increase in T-wave amplitude was observed in both control children and in those with aortic stenosis. No S-T segment abnormalities were noted in the normal children. Of the 16 patients with peak systolic left ventricular to aortic pressure gradients of less than 50 mm Hg, only one showed a segmental S-T depression. Of the 15 children with aortic valve gradients of 50 to 100 mm Hg, however, all except one showed an S-T segment depression in lead V5 of 2 mm or greater. No correlation between the resting electrocardiogram or the vectorcardiogram and the aortic valve gradient or left ventricular peak systolic pressure could be made. In addition, the abnormal S-T segment response to exercise could not be predicted from or correlated with the resting electrocardiogram. Since an ischemic S-T segment response to exercise was found uniformly in those with the higher gradients, this test appears to have a high degree of specificity in the clinical evaluation of these patients.

The telemetered exercise electrocardiogram in congenital aortic stenosis.

Five cases of an anomalous left coronary artery originating from the pulmonary artery have been presented. These illustrate different phases in the clinical spectrum of this anomaly. Two patients who presented with congestive failure and classic signs of myocardial infarction in early infancy underwent surgical ligation of the anomalous vessel. One survived and one died postoperatively, possibly with secondary residual mitral insufficiency as a contributory factor. Congestive failure and a clinical picture of mitral insufficiency developed in one other child at 1 year of age, and she died 10 months later with unremitting failure. Two children who were in failure in infancy, 1 with evidence of myocardial ischemia, have had a benign clinical course since that time. The clinical course and appropriate management of a patient would appear to depend upon the degree of development of the coronary collateral circulation. Some of the factors influencing the adequacy of these collateral vessels are postulated, including the presence of collateral channels at birth and the stimulation of new vessels by ischemia as the pulmonary arterial pressure falls. In those patients in whom the collateral circulation is adequate enough to allow survival, the clinical picture may be dominated by mitral regurgitation resulting from endocardial fibrosis with dilatation of the mitral valve ring.

Anomalous origin of the left coronary artery from the pulmonary artery: a clinical spectrum.

A study of ventricular septal defect associated with aortic insufficiency

Tolerance to acetyl strophanthidin, a rapid-acting cardiac aglycone, was determined in 28 anesthetized mongrel puppies, ages 16 to 56 days, and compared to tolerance in 16 littermate puppies in whom acute hypercapnic acidemia was produced. The tolerance was also compared to that of four adult mongrel dogs. The toxic dose was defined as the intravenous amount required to produce four consecutive premature ventricular contractions. A marked variation in the toxic dose was found in the 28 control puppies (range 83 to 353 µg/kg, mean 169 µg/kg) which could not be correlated with age, arterial blood gases or pH, serum potassium or sodium, arterial pressure, or heart rate. The toxic dose was significantly greater in the puppies than in the adult dogs, in whom the mean toxic dose was 64 µg/kg (range 50 to 89 µg/kg). A significant increase in tolerance was also observed in the puppies with hypercapnic acidemia (mean toxic dose 220 µg/kg, range 93 to 375 µg/kg) in comparison to tolerance in the control puppies and despite the wide range of tolerance, each of the puppies with hypercapnic acidemia showed greater tolerance than its littermate control puppy. Assessment of the clinical implications of these findings will require study of the effects of alterations in acid-base balance on the inotropic effect of acetyl strophanthidin in addition to the toxic electrophysiologic effects.

Katherine H. Halloran

Papers

Bronchial and Arterial Anomalies with Drainage of the Right Lung into the Inferior Vena Cava

The telemetered exercise electrocardiogram in congenital aortic stenosis.

Anomalous origin of the left coronary artery from the pulmonary artery: a clinical spectrum.

A study of ventricular septal defect associated with aortic insufficiency

Digitalis tolerance in young puppies