Antiarrhythmic and hemodynamic effects of the calcium channel antagonist verapamil were compared with those of tiapamil, a congener, in open-chest pigs with anterior descending coronary artery ligation. Tiapamil (6 mg/kg i.v.) decreased the incidence of ventricular fibrillation to 4 of 10 versus 22 of 25 in controls (p<0.05) and maintained left ventricular dP/dt,,x after ligation (predrug value...

After coronary artery occlusion, enzymes involved in the synthesis of sympathetic and parasympathetic neurotransmitters may change disparately. We investigated this in the canine heart by measuring the activity of tyrosine hydroxylase (TH) and choline acetyltransferase (CAT) in normal and ischemic tissue. Myocardial blood flow in selected regions was measured by the microsphere technique. Dogs ...

In the subacute phase of myocardial infarction following coronary ligation in dogs, a relationship was noted between the extent of infarction and the degree of elevation of left ventricular end-diastolic pressure. Left ventricular filling pressure was consistently increased when 25% or more of the left ventricle was infarcted. Isoproterenol infusion resulted in enhanced left ventricular functio...

We sought to determine whether the third component of complement (C3) is localized in ischemic baboon myocardium after coronary artery ligation. Furthermore, we assessed the effects of prior C3 depletion on myocardial necrosis. We studied seven control baboons (group I) and seven C3-depleted (group II) baboons that were killed 24 h after ligation of the anterior descending coronary artery. Mult...

OBJECTIVES We reported that the activation of gp130 transduced hypertrophic and cytoprotective signals via Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway in cardiac myocytes. Recent in vivo experiments have demonstrated that the JAK/STAT pathway is activated in acute pressure overload hearts. The present study was designed to examine whether the JAK/STAT pathwa...

AIMS The coronary artery ligation model in rodents mimics human myocardial infarction (MI). Normally mechanical ventilation and prolonged anesthesia period are needed. Recently, a method has been developed to create MI by popping-out the heart (without ventilation) followed by immediate suture ligation. Mortality is high due to the time-consuming suture ligation process while the heart is expos...

Our aim was to assess the timing and mechanisms of the sympathoexcitation that occurs immediately after coronary ligation. We recorded thoracic sympathetic (tSNA) and phrenic activities, heart rate (HR) and perfusion pressure in Wistar rats subjected to either ligation of the left anterior descending coronary artery (LAD) or Sham operated in the working heart-brainstem preparation. Thirty minut...

The catecholamines, dopamine, norepinephrine, and epinephrine, have been found in brain regions associated with cardiovascular regulation. We wished to determine whether central catecholaminergic neurons participate in the reflex alterations of cardiac autonomic nerve traffic associated with acute myocardial ischemia. Five groups of rats treated with a-methyltyrosine, an inhibitor of catecholam...

Repetitive episodes of brief regional ischemia have been shown to reduce the severity of life-threatening ventricular anhythrnias and infarct size that occur during prolonged occlusion of the coronary artery. This phenomenon is known as ischemic preconditioning. During studies in anesthetized, open chest Wistar rats, we accidentally observed that poorly ventilated animals had a reduced seve...

We report the case of a rare anomaly of the right coronary artery (RCA) arising from the left aortic sinus, having a single ostium with the left coronary artery, associated with documented episodes of inferior ischemia, in which surgical treatment with a right internal thoracic artery to RCA bypass graft and the corresponding ligation provided greater stability to the coronary blood flow and go...