Anomalous origin of the left anterior descending and circumflex coronary arteries by two separate ostia from the right sinus of Valsalva.

We report a case of absence of the left main coronary artery with the left anterior descending and circumflex coronary arteries arising by two separate ostia from the right sinus of Valsalva in a patient without other congenital cardiovascular malformations. The clinical and angiographic features of this exceedingly rare anomaly are described with a brief review of previously documented cases.

Usefulness of L-thyroxine to improve cardiac and exercise performance in idiopathic dilated cardiomyopathy.

The short-term effects of L-thyroxine (100 micrograms/day, 10 patients) and placebo (10 patients) on idiopathic dilated cardiomyopathy were compared. Before and at the end of the treatment, a hemodynamic study was performed in the control state and during dobutamine infusion. A cardiopulmonary exercise test was also performed with hemodynamic monitoring. An echocardiogram was recorded in the control state and during acute changes of left ventricular afterload. Plasma levels of triiodothyronine, thyroxine, thyroid-stimulating hormone and norepinephrine were measured. Placebo was ineffective. After administration of L-thyroxine all patients had normal thyroid function. The increase in left ventricular ejection fraction and the rightward shift of the slope of left ventricular ejection fraction/end-systolic stress relation (p < 0.05) indicated an improvement in the cardiac inotropic state. This proved to be independent of adrenergic influences by the unchanged beta 1 response to dobutamine. A decrease in resting systemic vascular resistances and an increase in cardiac output (p < 0.05) were also observed. Cardiopulmonary effort parameters improved (p < 0.05) without hemodynamic changes at peak exercise. It is concluded that L-thyroxine short-term administration improves cardiac and exercise performance in patients with chronic heart failure, without modifying the adrenergic support to the heart and the circulatory parameters at peak exercise.

[The improvement in physical exercise capacity in dilated cardiomyopathy during short-term treatment with L-thyroxine]. / Miglioramento della capacità di esercizio fisico nella cardiomiopatia dilatativa durante trattamento a breve termine con L-tiroxina.

Reduced left ventricular function and other factors, such as vascular resistances, redistribution of cardiac output and impaired muscular metabolism, limit exercise performance in chronic heart failure. Thyroid hormones have a positive cardiac inotropic effect, stimulate protein synthesis (particularly at muscular level) and reduce peripheral vascular resistances with consequent increase of cardiac output. Therefore, it is possible that thyroid hormones can improve exercise performance in chronic heart failure. We have administered L-thyroxin (100 mcg/die) for 1 week to 9 patients affected by primary dilated cardiomyopathy. All the patients were euthyroid (T3 = 1.06 +/- 0.1 mcg/ml, T4 = 8.5 +/- 1.9 mcg/dl, TSH = 1.32 +/- 0.7 mU/ml) and in II-III NYHA functional class. Before starting the treatment and at the end of it, we performed the cardiopulmonary exercise test and the echocardiogram. We also evaluated the resting hemodynamic parameters through catheterization and the plasmatic values of thyroid hormones and noradrenaline. At the end of the treatment all patients were euthyroid, despite a significant (p less than 0.05) increase of T4 (10.5 +/- 3.2 mcg/dl) and a decrease of TSH (1.1 +/- 0.1 mU/ml). Mean values of effort parameters changed as follows: peak oxygen consumption from 19.6 +/- 1.6 to 20.6 +/- 1.3 ml/min/kg, tolerance time from 460 +/- 61 to 481 +/- 60 s. These variations were not associated with changes in resting hemodynamic parameters and noradrenaline. Left ventricular ejection fraction, calculated by echocardiography, increased from 26 +/- 6 to 28.9 +/- 8% (p less than 0.05). We conclude that in dilated cardiomyopathy short term treatment with L-thyroxin significantly improves patient's response to cardiopulmonary exercise test.(ABSTRACT TRUNCATED AT 250 WORDS)

[Changes in pulmonary vascular reactivity to adrenergic stimuli in congestive heart failure]. / Modificazioni della reattività vascolare polmonare agli stimoli adrenergici nello scompenso cardiaco congestizio.

Heart failure is associated with increased activity of sympathetic nervous system. As to the latter's effector organs, attention has been mainly drawn by heart and systemic circulation. In this study we investigated whether and how the neurogenic vasomotility of the lesser circulation is modified. Therefore, we compared 12 patients with heart failure in III NYHA functional class, with 10 subjects, undergoing hemodynamic study for diagnostic reasons and found to be normal. The neurogenic reactivity of pulmonary vessels was assayed by means of 2 sympathetic stimuli: arithmetic test (AT) and cold pressor test (CPT), performed both with and without obstruction to right heart venous return. This was obtained by expanding a balloon in inferior vena cava, in order to rid the neurogenic component of pulmonary vasomotility of the interference of the normally prevailing mechanical component (consisting in adaptations to flow variations). AT caused pulmonary vasodilation in normal subjects, as a passive consequence of the increase of cardiac output and, therefore, of pulmonary flow. Caval obstruction, by simply restraining this increase, induced a clearly neurogenic vasoconstrictor response. On the contrary, in failing patients, a slight vasodilation, independently from the condition of venous return, was observed. This took place in spite of the constant absence of any variations of cardiac output, which both indicates the reduction of myocardial function and helps to show the diminished nervous influence on pulmonary circulation. On the other hand, CPT had a vasoconstrictor effect in both groups, though potentiated by the reduction of transpulmonary flow in normal subjects only.(ABSTRACT TRUNCATED AT 250 WORDS)