From 1988 to 1991, 200 consecutive patients (18 female, 182 male, mean age 55.4 +/- 9 years) with chronic coronary occlusions resistant to recanalization by conventional techniques were treated by low speed rotational angioplasty. Indication was based on preserved left ventricular contraction and on exercise-induced symptoms or exercise induced signs of myocardial ischaemia. Duration of occlusion ranged from 1 to 192 months (median 6 months, interquartile range 4-9 months, mean 12 +/- 26 months). Success rate was 91% in occlusions 4 weeks-3 months old, 72% in occlusions 4-6 months old, 55% in occlusions 6-12 months old and 8% in occlusions older than 12 months. In 99 of 116 successfully treated patients (85%) follow-up angiography was performed 4 months after recanalization. In 80/99 (81%) patients the vessel remained open. Fifty of these 80 patients needed no further intervention, while 30/80 of the patients had restenosis treated by a second PTCA in 28 patients. Nineteen of the 99 (19%) patients had reocclusions. Including cases submitted to a second dilation, and angiographically determined long-term patency 4 months after successful recanalization was thus achieved in 78/99 (78%) of patients. Minor complications included asymptomatic dissection in the recanalized vascular region. Serious complications occurred in two proximal occlusions of the left anterior descending coronary artery dissecting into the adjacent circumflex branch, and embolism into distal parts of recanalized vessels. It is concluded that in selected patients low speed rotational angioplasty (Rotacs) is a safe technique applicable to chronic total coronary occlusions even if the duration of occlusion exceeds 6 months and after conventional techniques have failed.(ABSTRACT TRUNCATED AT 250 WORDS)