Activation of left ventricular receptors with nonmedullated vagal afferent fibers during occlusion of a coronary artery in the cat

Thorén, Peter

doi:10.1016/0002-9149(76)90422-7

Cited by 138 publications

(36 citation statements)

References 28 publications

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“…The renal nerve responses we observed were quite different from the skeletal muscle vascular responses to coronary occlusion that have been previously reported (2,3,5,13,26 (9,10).…”

Section: Ilycontrasting

confidence: 87%

Reflex Inhibition of Renal Sympathetic Nerve Activity during Myocardial Ischemia Mediated by Left Ventricular Receptors with Vagal Afferents in Dogs

Thames¹,

Abboud²

1979

J. Clin. Invest.

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A B S T R A C T The major goal ofthis investigation was to determine if activation of cardiac receptors during coronary artery occlusion could inhibit efferent renal sympathetic nerve activity. In nine chloralose anesthetized dogs with only carotid (n = 3) or with sinoaortic (n = 6) baroreceptors operative, anterior descending coronary artery (LAD) occlusion resulted in a small decrease in mean arterial pressure (-9.8+±5.1 mm Hg, NS) and in a significant (P < 0.05) increase in renal nerve activity (24.0±4.1%). In these dogs, circumflex coronary artery (Cx) occlusion resulted in greater hypotension (-18

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“…The renal nerve responses we observed were quite different from the skeletal muscle vascular responses to coronary occlusion that have been previously reported (2,3,5,13,26 (9,10).…”

Section: Ilycontrasting

confidence: 87%

Reflex Inhibition of Renal Sympathetic Nerve Activity during Myocardial Ischemia Mediated by Left Ventricular Receptors with Vagal Afferents in Dogs

Thames¹,

Abboud²

1979

J. Clin. Invest.

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“…Myocardial ischemia excites both vagal25 26 has the potential of impairing vagally mediated maintenance of an optimal heart rate, thereby facilitating the occurrence of a dangerous tachycardia.…”

Section: Discussionmentioning

confidence: 99%

Autonomic mechanisms in ventricular fibrillation induced by myocardial ischemia during exercise in dogs with healed myocardial infarction. An experimental preparation for sudden cardiac death.

Schwartz¹,

Billman²,

Stone³

1984

Circulation

428

186

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The relationship between activity of the autonomic nervous system, myocardial ischemia, and malignant arrhythmias has been investigated in a new experimental preparation for sudden death. Fifty-seven dogs were chronically instrumented and studied under control conditions (n = 15) and 1 month after production of an anterior myocardial infarction (n = 42). The protocol consisted in occluding the left circumflex coronary artery for 2 min, commencing at the last minute of an exercise stress test and extending through the first minute after cessation of exercise. With this protocol, ventricular fibrillation was observed in 40% of normal dogs and 66% of dogs with infarction. In 14 dogs.with infarction, left stellectomy reduced the incidence of ventricular fibrillation to zero (p < .001). The reflex changes in heart rate elicited within the first minute of ischemia during exercise in the animals that survived (from 204 ± 14 to 198 ± 31 beats/min, -6) were opposite those in animals that had ventricular fibrillation (from 208 24 to 229 30 beats/min, + 21) (p < .05). The ischemiainduced reduction in heart rate despite continuation of exercise suggests the presence in the dogs that survived of active vagal reflexes that may have played an important role in the maintenance of cardiac electrical stability. This preparation has the potential to induce ventricular fibrillation consistently in conscious animals by the interaction of a few clinically relevant factors (acute myocardial ischemia, submaximal exercise and its cessation, sympathetic and vagal reflexes, and heart rate) and offers the possibility of acquiring further insights into the mechanisms of malignant arrhythmias and evaluating novel strategies for targeted prevention. Circulation 69, No. 4, 790-800, 1984. TARGETED prevention of sudden cardiac death depends on an adequate understanding of the mechanisms of and the factors leading to ventricular fibrillation, as well as an understanding of their relative roles. Basic electrophysiologic experiments, usually performed in isolated hearts or in open-chest preparations, are designed to identify these factors and their probable modes of action, but comprehension of their relative roles in the clinical setting requires experiments in unanesthetized animals.Necessary to achieve this goal are the identification of the most critical factors, the capability of controlling

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“…First, with a longer period of the occlusion, a greater variability in the ERP change was observed as well as an increased incidence of serious ventricular arrhythmias which hindered an accurate measurement of ERP. The second reason was that, in view of the previous studies (FELDER and THAMES, 1979;TWAMURA and BISHOP, 1980;THOREN, 1976;WEAVER et al, 1981), 90 sec was considered sufficiently long for the development of reflex alteration of ventricular refractoriness, and a much longer period of occlusion might allow mechanisms other than autonomic reflexes to take place.…”

Section: Discussionmentioning

confidence: 99%

“…Although the study demonstrated a cardiocardiac reflex which can alter the refractoriness of the heart, it is still unknown whether the activation of ventricular receptors may exert similar reflex influences on ventricular refractoriness. One of the conditions which alter ventricular receptor activity is acute myocardial ischemia (BROWN, 1967;IWAMURA and BISHOP, 1980;MALLIANI et al, 1969;THOREN, 1976;UCHIDA and MURAO, 1974;WEAVER et al, 1981). Activation of cardiac receptors during myocardial ischemia has been known to significantly alter both sympathetic and parasympathetic influences on the heart (FELDER and THAMES, 1979;GILLIS,1971).…”

mentioning

confidence: 99%

Reflex control of ventricular refractoriness in the nonischemic myocardium during coronary occlusion.

et al. 1983

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The purpose of the study was to determine whether activation of cardiac receptors and arterial baroreceptors by myocardial ischemia could elicit reflex alteration of the effective refractory period (ERP) of nonischemic ventricular myocardium in cats. Changes in ERP of nonischemic area of the right ventricle and mean arterial pressure (MAP) were measured during transient left anterior descending (LAD) coronary artery occlusion in anesthetized cats. LAD coronary occlusion for 90 sec caused a small but significant shortening of ERP (maximal change=2.5±2.3 msec) associated with a decrease in MAP. Vagotomy significantly augmented the shortening of ERP to -3.4+ 1.6 msec and attenuated the decrease in MAP. After selective cardiac sympathectomy, the reflex response in refractoriness was virtually abolished. In cats with sinoaortic denervation with intact sympathetic nerves, marked attenuation was observed in the reflex change in refractoriness, although the decrease in MAP was significantly greater. These results indicate that : (1) autonomic reflexes activated during acute myocardial ischemia shorten the refractory period of nonischemic ventricular myocardium; (2) the reflex response is predominantly mediated by enhancement of cardiac sympathetic nerve activity resulting from the reduced baroreceptor activity due to concurrent hypotension.

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Activation of left ventricular receptors with nonmedullated vagal afferent fibers during occlusion of a coronary artery in the cat

Cited by 138 publications

References 28 publications

Reflex Inhibition of Renal Sympathetic Nerve Activity during Myocardial Ischemia Mediated by Left Ventricular Receptors with Vagal Afferents in Dogs

Reflex Inhibition of Renal Sympathetic Nerve Activity during Myocardial Ischemia Mediated by Left Ventricular Receptors with Vagal Afferents in Dogs

Autonomic mechanisms in ventricular fibrillation induced by myocardial ischemia during exercise in dogs with healed myocardial infarction. An experimental preparation for sudden cardiac death.

Reflex control of ventricular refractoriness in the nonischemic myocardium during coronary occlusion.

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