The Coronary Circulation

Ratnoff, Oscar D.; Plotz, Milton

doi:10.1097/00005792-194609000-00002

Cited by 9 publications

(1 citation statement)

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“…3 It seems unlikely that the T-wave depressions and inversions, elicited by injected or by nitroglycerin is of no significance in accounting for the nitroglycerin-induced diminution of the T wave under depression caused by the sympathomimetic amines, since the T-wave changes have been shown to be entirely independent of the pressor effects of these amines. 23 Unless we deliberately disregard the functional significance of myocardial metabolism COW HEART SYMPATHIN (5St eu., 4ec, 2 neurally dischargedl7 sympathomimetic amines, should be due to a diminution of the coronary flow, since most investigators agree that the coronary flow is increased rather than decreased by these agents'7 19,20 and by stimulation of the cardiac sympathetic fibers.2"' 21, 22, 29. 26 Likewise, it is improbable that the diminution or abolition of the adrenergic T-w'ave changes by nitroglycerin should be caused by further dilatation of the coronary arteries, nor can the counteraction of nitroglycerin against the sympathomimetic neurohormonal acceleration of the heart be ascribed simply to coronary dilatation.…”

Section: Resultsmentioning

confidence: 99%

Anti-Adrenergic Effects of Nitroglycerin on the Heart

Raab

Lepeschkin

1950

Circulation

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The therapeutic effect of nitroglycerin is geneially attributed to its coronary dilator effect alone. In contrast, it could be shown that nitroglycerin also counteracts the chronotropic as wvell as the electiocardiographic T-wave (leplessing effects of epinep)hline, arterenol and caldiac syml)athinl upon the heart. Accordingly, its therapeutic action in angina pectoris is suspected as being largely due to a chemical protection of the heart muscle against the chemically anoxialpro(lucing effects of sympathoniimetic amines.T HERE is a widespread tendency among cardiologists to interpret the mechanism of functional cardiac changes primarily or exclusively in terms of alterations of the coronary blood flow or of cardiac muscular dynamics, while little or no attention is paid to the fundamental role of myocardial cell metabolism and its neurohormonal regulation. This tendency applies also to the evaluation of the effects of nitroglycerin, the coronary-dilator action of which is generally assumed to explain all of its cardiac manifestations and especially its therapeutic efficiency in angina pectoris.However, some investigations, dealing with the chemically anoxia-producing effects of sympathomimetic neurohormones and their derivatives1' 15 16' 24, 26and with the probable pathogenic role of epinephrine and sympathin in the origin of the anginal syndrome,2 have made the purely mechanistic conception of the action of nitroglycerin on the heart questionable. They have put emphasis on the possibility that nitroglycerin might interfere with the oxygen-consuming, anoxia-producing effects of epinephrine-sympathin on the contractile substance of the heart directly, in a way similar to the direct counteraction exerted by nitroglycerin against the vasopressor effect of epinephrine on the contractile substance of the blood vessels.3 A specific indication of such an antiadrenergic action of nitroglycerin on the heart was seen in the fact that the cardioaccelerator effects of epiFrom the Division of Experimental Medicine, Universitv of Vermont, College of Medicine, Burlington, Vt. This study was aided by a grant from the National Institute of Health.nephrine, of stimulation of the stellate ganglia, and of acetylcholine in the atropinized cat were maikedly diminished in the presence of nitroglycerin.The following experiments were carried out in order to further elucidate the interference of nitroglycerin with adrenergic actions upon the heart. METHODSAtropinized cats under N embutal anesthesia, with the adrenal glands tied, and with artificial respiration, were used throughout. Rapid intravenous injections were given in an exposed femoral vein; slow infusions were made with a motor-driven syringe, operating at a constant velocity and connected with a femoral vein. The stellate ganglia were stimulated by means of attached shielded-wire electrodes and a "Variac" transformer at a voltage of 10. The blood pressure was recorded from a common carotid artery. Electrocardiograms were synchronized with corresponding points of the blood p...

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Section: Resultsmentioning

confidence: 99%

Anti-Adrenergic Effects of Nitroglycerin on the Heart

Raab

Lepeschkin

1950

Circulation

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Die Coronarerkrankungen. Coronarinsuffizienz, Angina pectoris und Herzinfarkt

Schimert¹,

Schimmler²,

Schwalb³

et al. 1960

Angeborene Herz- Und Gefässmissbildungen Durchblutungsstörungen Des Herzmuskels

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Variations of the origin of the artery of the sinoatrial node in normal human hearts

et al. 1995

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The artery of the sino-atrial node was studied in 100 normal human hearts after injection of each coronary artery with coloured gelatine containing a radiopaque substance. The hearts belonged to 69 males and 31 females, being 64 Caucasians and 36 non-Caucasians (Negroes and Mulattoes) whose age ranged from 7 to 80 years. Since the individuals had committed suicide or were victims of accidents, their hearts, after pathologists' evaluation, were considered normal. The sinoatrial node of the normal human heart is supplied by the right coronary artery more frequently (58% +/- 4.9% of the cases) than by the left (42% +/- 4.9). The right anterior medial atrial artery, originating from the right coronary at the level of the medial third of the right anterior quadrant of the atrial dome, is most frequently (50% +/- 5) responsible for the blood supply of the sinoatrial node. Among the branches of the left coronary artery, the left anterior medial atrial artery, originating at the level of the medial third of the left. anterior quadrant of the atrial cupola, was the most frequent blood supplier (25% +/- 4.3) of the sinoatrial node. The origin of the artery of the sinoatrial node from the proximal portion or trunk of the left coronary artery was less frequent (12% +/- 3.2) than the origin from the circumflex artery (30% +/- 4.5). Neither sex nor race influenced the variations of the origin of the sino-atrial node.

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The Coronary Circulation

Cited by 9 publications

References 0 publications

Anti-Adrenergic Effects of Nitroglycerin on the Heart

Anti-Adrenergic Effects of Nitroglycerin on the Heart

Die Coronarerkrankungen. Coronarinsuffizienz, Angina pectoris und Herzinfarkt

Variations of the origin of the artery of the sinoatrial node in normal human hearts

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