Diazepam administered prior to coronary artery occlusion increases latency to ventricular fibrillation

Life Sciences ◽  
1991 ◽  
Vol 49 (8) ◽  
pp. 587-594 ◽  
Author(s):  
Judith M.B. Pinto ◽  
Debra A. Kirby ◽  
David A. Johnson ◽  
Bernard Lown
Keyword(s):  
Coronary Artery ◽  
Ventricular Fibrillation ◽  
Coronary Artery Occlusion ◽  
Artery Occlusion

Vagal reflexes and survival during acute myocardial ischemia in conscious dogs with healed myocardial infarction

1991 ◽  
Vol 261 (1) ◽  
pp. H63-H69 ◽  
Author(s):  
G. M. De Ferrari ◽  
E. Vanoli ◽  
M. Stramba-Badiale ◽  
S. S. Hull ◽  
R. D. Foreman ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Heart Rate ◽  
Coronary Artery ◽  
Ventricular Fibrillation ◽  
Myocardial Ischemia ◽  
Coronary Artery Occlusion ◽  
Artery Occlusion ◽  
Acute Myocardial Ischemia ◽  
Acute Ischemia ◽  
Control Test

The role of vagal tone and reflexes in the genesis of life-threatening arrhythmias was investigated in a clinically relevant animal model for sudden cardiac death. Forty-five dogs with a healed anterior myocardial infarction in which transient myocardial ischemia during exercise did not induce malignant arrhythmias were utilized for the study. They underwent a further exercise and ischemia test in which atropine (75 micrograms/kg) was injected before coronary artery occlusion. Novel occurrence of ventricular arrhythmia, or worsening of the type of arrhythmia present in the control test, occurred in 23 of 45 dogs (51%) and ventricular fibrillation occurred in 11 of 45 (24%, P = 0.001). Analysis of heart rate response to acute ischemia in the control test indicates that these 11 animals had powerful vagal reflexes during coronary artery occlusion, compared with the 34 survivors (-32 +/- 35 vs. +2 +/- 27 beats/min, P = 0.003). This study indicates that approximately 75% of animals resistant to ventricular fibrillation are characterized by weak sympathetic reflexes in response to acute myocardial ischemia. In the remaining 25% powerful vagal reflexes counteract concomitant reflex sympathetic hyperactivity, decrease heart rate, and are essential for survival.

scholarly journals Ventricular fibrillation after acute coronary artery occlusion

1967 ◽  
Vol 53 (3) ◽  
pp. 335-340 ◽  
Author(s):  
Roque Pifarré ◽  
Taro Yokoyama ◽  
Apolinar C. Ilano ◽  
Charles A. Hufnagel
Keyword(s):  
Coronary Artery ◽  
Ventricular Fibrillation ◽  
Coronary Artery Occlusion ◽  
Artery Occlusion

Antifibrillatory effects of α1-adrenoceptor blocking drugs in experimental coronary artery occlusion and reperfusion

1993 ◽  
Vol 71 (2) ◽  
pp. 103-111 ◽  
Author(s):  
B. G. Benfey
Keyword(s):  
Coronary Artery ◽  
Ventricular Fibrillation ◽  
Guinea Pig ◽  
Ventricular Arrhythmias ◽  
Coronary Occlusion ◽  
Coronary Artery Occlusion ◽  
Artery Occlusion ◽  
Coronary Reperfusion ◽  
Isolated Hearts ◽  
Anesthetized Dogs

The myocardium of animals and man possesses α1-adrenoceptors in addition to β-adrenoceptors. Ischemia increases sympathetic tone, and ventricular arrhythmias can occur by β- and α1-adrenoceptor stimulation. I believe that α1-adrenoceptor blocking drugs have antifibrillatory effects and will review the data that support this condition. The effect of α1,-adrenoceptor blocking drugs on the incidence of ventricular fibrillation in acute coronary artery occlusion and (or) reperfusion has been determined in 24 studies in conscious and anesthetized dogs and rats, anesthetized cats and pigs, and rat and guinea-pig isolated hearts. The drugs reduced the incidence of fibrillation from 35 to 24% in coronary occlusion and from 61 to 29% in reperfusion.Key words: heart, coronary occlusion, coronary reperfusion, ventricular fibrillation, α1-adrenoceptor blocking drugs.

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