Indirect assessment of acute effects of ethyl alcohol on coronary circulation in patients with chronic stable angina.

Acute effects of ethyl alcohol on left ventricular performance, haemodynamic and electrocardiographic response to treadmill exercise test were studied in 20 patients with chronic stable angina. Following ingestion of 80 ml of whisky (43% ethyl alcohol by volume) the mean heart rate and rate-pressure product decreased significantly at the end of each stage of exercise compared to corresponding prealcohol values. There were also significant derangements in systolic time intervals parameters in the form of decrease in left ventricular ejection time I and increase in pre-ejection phase I and pre-ejection phase/left ventricular ejection time ratio after alcohol intake indicating a depression in left ventricular performance. However, following alcohol intake the mean exercise time (6.5 +/- 3.8 minutes) until onset of ischaemic ST segment depression decreased significantly (P less than 0.01) compared to the corresponding prealcohol exercise time (8.6 +/- 3.5 minutes). Interestingly, the mean rate-pressure product (an indicator of myocardial oxygen demand) at the onset of ischaemic ST segment depression was significantly less (P less than 0.01) when exercise test was done after alcohol intake compared to the corresponding pre-alcohol value. The data indicated that despite significant decrease in myocardial oxygen demand produced by alcohol intake, ST T changes developed early and at a lower rate-pressure product, indicating decreased blood flow to the ischaemic zones of the myocardium. This may be explained by the coronary steal effect produced by alcohol.