We report our experience of 15 transluminal coronary angioplasties performed in an emergency in 13 patients (mean age 67 +/- 8 years) with refractory unstable angina. The procedures were conducted under diastolic counterpulsation effected by means of an intra-aortic balloon. The angina was of the threatening infarction type on 11 occasions and of the threatening extended infarction on 4 occasions. Electrocardiographic abnormalities were recorded in the anterior (11 cases) or in the inferior (4 cases) territory. Three patients had a very alarming haemodynamic status, with acute pulmonary oedema in two and cardiogenic shock in one. After intra-aortic counterpulsation was installed and the clinical signs were stabilized, coronaro-ventriculography was performed, leading to a decision of immediate angioplasty since age, underlying diseases, myocardial function and diffused lesions made most of the patients unsuitable for surgery. In multiple vessel patients electric and angiographic data were used to locate the tight stenosis (92% in all cases) responsible for the acute coronary ischaemia. The stenosis was found to affect the anterior interventricular artery in 9 cases, the circumflex artery in 2 cases, the right coronary artery in 2 cases and a saphenous shunt on the anterior interventricular artery in 2 cases. Immediate arteriographic and clinical success was obtained in 12 out of 15 cases (80%); there were 3 failures with 2 transmural infarctions. Later on, 2 patients underwent aorto-coronary bypass and 1 died of myocardial failure and pulmonary superinfection 3 weeks after the procedure. Ten of our 13 patients were stabilized and were discharged under medical treatment.(ABSTRACT TRUNCATED AT 250 WORDS)