Acute Complete Heart Block in Dogs

Starzl, TE; Gaertner, Robert A.; Baker, R. Robinson

doi:10.1161/01.cir.12.1.82

Cited by 72 publications

(15 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The assumption was made that any negative chronotropic effects of glycosides on the atropinized sinus node were due to a direct effect. Our experiments and those of others (5,6,11) have shown that this conclusion is incorrect. It is clear that there is a significant component to the extravagal action of digitalis which is mediated by modifying the normal sympathetic influence on heart rate.…”

Section: Direct Chronotropic Action Of Cardiac Glycosides On the Sinucontrasting

confidence: 63%

Chronotropic Effect of Cardiac Glycosides in Cats, Dogs, and Rabbits

Eick

Hoffman

1969

Circulation Research

View full text Add to dashboard Cite

We have tested the widely accepted hypothesis that digitalis, in nontoxic concentration, can act directly on cells of the sinoatrial pacemaker to cause slowing. The effect of autonomic nerves on sinoatrial cells was eliminated either by chronic cardiac denervation or by use of autonomic blocking agents such as atropine, 0.5 mg/kg, and propranolol, 2 mg/kg, or MJ-1999, 3 mg/kg. When the effects of autonomic nerves were eliminated, acetylstrophanthidin, 0.120 mg/kg, failed to cause slowing of sinus rate in the anesthetized cat and the anesthetized dog. Similarly, ouabain, 5 X 10~"M, and acetylstrophanthidin, 1.5 /ig/ml, after prior administration of autonomic blocking agents failed to cause slowing of the isolated rabbit right atrium perfused with Tyrode's solution. These results indicate that the sinus slowing caused by cardiac glycosides may be mediated entirely by alteration of the neural control of the heart and that the drug, in nontoxic concentration, does not have a direct negative chronotropic action on the mammalian sinoatrial node. has been presented by Mendez et al. (5) and by Nadeau and James (6). Prior to their studies (5, 6), any sinus bradycardia induced by cardiac glycosides and not blocked by vagotomy or by administration of atropine was attributed to a direct effect of the glycoside on the sinoatrial node (7,8). Therefore, at least three actions of cardiac glycosides which might cause sinus bradycardia have been described: (1) a vagal effect, (2) an effect which modifies the normal sympathetic influence on heart rate, hereafter referred to as "the sympathetic modifying effect," and (3) a direct negative chronotropic effect. The vagal and sympathetic modifying effects of cardiac glycosides alter sinus rate by modifying reflex mechanisms and are properly classified as indirect chronotropic effects. If,

show abstract

Section: Direct Chronotropic Action Of Cardiac Glycosides On the Sinucontrasting

confidence: 63%

Chronotropic Effect of Cardiac Glycosides in Cats, Dogs, and Rabbits

Eick

Hoffman

1969

Circulation Research

View full text Add to dashboard Cite

show abstract

“…Wegria, Wang and Glaviano (4) in 1955 stimulated the left atrial appendage and recorded an increase in the coronary blood flow, together with a fall in the systemic arterial blood pressure and cardiac output. In 1956 Laurent, Bolene-Williams, Williams and Katz (5) showed a direct relationship between heart rate and coronary flow, as did Duff, Berglund and Borst (6); a reduction in left coronary flow with slowing of the heart was observed by Starzl, Gaertner and Baker (7).…”

mentioning

confidence: 86%

Induced Tachycardia: Its Effect upon the Coronary Hemodynamics, Myocardial Metabolism and Cardiac Efficiency of the Intact Dog12

Maxwell¹,

Castillo²,

White³

et al. 1958

J. Clin. Invest.

View full text Add to dashboard Cite

“…X-ray films, taken immediately and for as long as the animals lived, revealed an invariable enlargement of the cardiac shadow ( fig. 3) It has been shown that the cardiac output of dogs is considerably reduced immediately after the surgical production of complete heart block (1,5). This explains the clinical behavior of the dogs during the first two to seven days.…”

Section: Espite the Inherent Limitations Ofmentioning

confidence: 99%

Chronic Heart Block in Dogs. A Method for Producing Experimental Heart Failure

1955

Self Cite

View full text Add to dashboard Cite

A method is described for the production of chronic atrioventricular block in dogs, by incision of the region of the bundle of His through the open right atrium during temporary caval occlusion. Exercise tolerances, chest x-ray films, electrocardiograms, phonocardiograms, cardiac outputs, intracardiac pressures, femoral pressures, and left ventricular coronary flows were obtained preoperatively and from 1 to 10 months postoperatively. The majority of the animals developed clinical, laboratory, and pathological evidence of congestive heart failure. All animals had generalized myocardial hypertrophy.D ESPITE the inherent limitations of itransferring data on experimental [heart disease from animals to man, it is possible, after surgical production of lesions in animals, to make controlled analyses of various syndromes which are analogous to human disease entities. In a contemporary study in dogs' the acute effect of surgically induced complete heart block on cardiocirculatory function was reported. The present communication is concerned with a study of the chronic effects of complete heart block in dogs, as well as with a more detailed description of the operative procedure.During the study, the majority of the animals with chronic complete heart block developed right and left sided heart failure, either spontaneously or after several weeks of daily exercise. Because of the current interest in developinig experimental means of producing congestive heart failure, the events and details of decompensation have been

show abstract

Acute Complete Heart Block in Dogs

Abstract: A study has been conducted immediately and up to 18 (lays after the surgical production of complete heart block in dogs. Immediately Ju1ly, 19.55

Cited by 72 publications

References 14 publications

Chronotropic Effect of Cardiac Glycosides in Cats, Dogs, and Rabbits

Chronotropic Effect of Cardiac Glycosides in Cats, Dogs, and Rabbits

Induced Tachycardia: Its Effect upon the Coronary Hemodynamics, Myocardial Metabolism and Cardiac Efficiency of the Intact Dog12

Chronic Heart Block in Dogs. A Method for Producing Experimental Heart Failure

Contact Info

Product

Resources

About