Effects of Halothane on Coronary Haemodynamics and Myocardial Metabolism in Patients with Ischaemic Heart Disease and Heart Failure

Abstract

Halothane was administered at an end-tidal concentration of 1 % to 10 patients with stable ischaemic heart disease and clinical and haemdynamic signs of moderate heart failure. Measurements of central haeniodynamic variables, coronary sinus blood flow and oxygen, lactate and hypoxanthine balances over the myocardium were done before and at steady state during halothane anaesthesia. Halothane induced marked haemodynamic changes with decreases in mean arterial pressure (-43 %), mean pulmonary arteriolar occlusion pressure (-42%), systemic vascular resistance (-31 %), cardiac index (-20%), stroke volume index (-31 %) and left and right stroke work indices (-62% and -5573, respectively). Heart rate and pulmonary vascular resistance did not change. Coronary sinus blood flow decreased in parallel with perfusion pressure, and myocardial oxygen consumption decreased (-40%), as did myocardial oxygen extraction. Rate pressure product and triple product correlated better with changes in myocardial oxygen consumption in the present subset of patients than in healthy volunteers during halothane anaesthesia. The findings suggest that halothane, through its systemic vasodilatory effect, unloads the failing left ventricle and that this peripheral action predominates over the direct cardiodepressant action of the agent. The combined findings of unchanged coronary vascular resistance, decreased myocardial oxygen extraction and absence of increasing or pathological levels of lactate and hypoxanthine in coronary sinus blood imply a direct dilatory effect of halothane on the coronary vasculature.

Coronary Haemodynamic Effects of Surgery during Enflurane‐Nitrous Oxide Anaesthesia in Patients with Ischaemic Heart Disease

“…Coronary sinus blood flow was determined by the continuous retrograde thermodilution technique, using room temperature normal saline as the indicator, injected at approximately 40 ml/min during 15-20 s for each measurement. All methods for pressure and flow measurements have previously been described in detail (7). Blood was sampled simultaneously from the artery, pulmonary artery and the coronary sinus for determination of oxygen content (13), lactate concentration (14) and adrenaline-noradrenaline concentrations (15) at each measurement period.…”

Anaesthesia for abdominal aortic surgery — a review (Part II)

“…In contrast, the same authors noted decreased cardiac index, systemic vascular resistance, coronary sinus blood flow, myocardial oxygen consumption and no myocardial lactate production in aortic vascular surgery patients with coronary artery disease and evidence of heart failure using one per cent end-tidal halothane in 30 per cent oxygen . 220 The authors suggested that unloading of the left ventricle by systemic vasodilatation predominates over the cardiac-depressant action of halothane in this patient population.…”

Myocardial circulatory and metabolic effects of halothane when used to control intraoperative hypertension in patients with coronary artery disease

“…These effects, in combination with unchanged myocardial lactate metabolism, indicate that halothane preserves myocardial oxygen balance in patients with CAD (1)(2)(3)(4). These effects, in combination with unchanged myocardial lactate metabolism, indicate that halothane preserves myocardial oxygen balance in patients with CAD (1)(2)(3)(4).…”