Improvement in regional ventricular function after percutaneous transluminal coronary angioplasty.

We performed atrial pacing and radionuclide ventriculography in 12 patients before and after percutaneous transluminal coronary angioplasty (PTCA). Successful dilatation was achieved in 9 patients while in 3 the procedure was unsuccessful. Atrial pacing before PTCA showed ischemic dysfunction of the region supplied by the narrowed coronary artery. Regional ejection fraction decreased by 36 +/- 12% during rapid atrial pacing, while global left ventricular ejection fraction fell by 11 +/- 7% with a secondary increase in end-diastolic and end-systolic ventricular volume with the onset of ischemia. After successful PTCA, ischemic dysfunction was ameliorated or abolished. Measurements made at identical heart rates showed that both global and in particular regional left ventricular ejection fraction were significantly higher after successful angioplasty and did not fall during the stress of atrial pacing. There was no improvement in regional or global LV function in patients in whom angioplasty was not successful. The study showed that nuclear ventriculography with the stress of graded atrial pacing was a useful method for analysing the immediate results of coronary angioplasty and for studying its effects on regional myocardial function.