To examine left ventricular (LV) myocardial perfusion and function, in systemic sclerosis. Myocardial perfusion was assessed at rest, during cold exposure, and at peak exercise in 10 patients with systemic sclerosis. Seven of the 10 patients were examined with Doppler echocardiography; before and after long-term diltiazem treatment. Compared with average resting values, isotope uptake was increased by 48% after exercise, compared with cold exposure the exercise value was increased by 35%. After 11 months of diltiazem treatment there was no change in myocardial uptake, compared with respective values before treatment. Doppler echocardiography showed an increase in LV end-diastolic diameter, fractional shortening, and left ventricular outflow tract velocity, after treatment. This indicates that long-term diltiazem treatment does not increase myocardial perfusion at rest, post-exercise, or during cold exposure. On the other hand diltiazem treatment may improve left ventricular performance.