Prediction of improvement of left ventricular systolic function by dobutamine echocardiography after recent myocardial infarction

Left ventricular ejection fraction is a major prognostic factor of ischaemi c heart disease. In the early phase of myocardial infarction. part of the m yocardium may be stunned and responsible for marked segmental wall dysfunct ion which is potentially reversible. The authors studied the potential of l ow dose dobutamine echocardiography to predict secondary improvement of lef t ventricular systolic function in 21 patients with recent inaugural myocar dial infarction without primary angioplasty. All patients were treated and the investigation was carried out up to 20 mug/Kg/min of dobutamine without unwanted side-effects or myocardial ischaemia. The detection of viability by this method was associated with improved wall motion of the affected seg ments in 74% of cases, most of which had benefited from myocardial revascul arisation at control echocardiography performed 8 weeks later. If 4 or more segments were estimated to be viable initially, the left ventricular eject ion fraction improved to a value comparable to that obtained at a dosage of 20 mug/Kg/min of dobutamine. On the other hand, there was no secondary improvement in 76% of segments es timated to be non-viable whether or not they had been revascularised. The s ensitivity, specificity, positive and negative predictive values of low dos e dobutamine echocardiography for prediction of myocardial recovery after r ecent infarction were respectively 71, 79, 74 and 76%. The results of this investigation show prognostic value and could be an aid to the decision concerning revascularisation of patients not having underg one primary angioplasty.