[Assessment of the myocardial functional reserve in patients with left ventricular aneurysm by radionuclide ventriculography. Response to isotonic exercise].

Purpose: To evaluate global and regional left ventricular (LV) ejection fractions (EF) by radionuclide ventriculography in patients with LV aneurysm at rest and during isotonic exercise.

Methods: Twenty patients were studied by radionuclide ventriculography at rest and during exercise. All patients had been submitted to cineangiography and showed LV aneurysm post myocardial infarction.

Results: Patients were divided according to LV EF in two groups: one with EF > or = 40% and the other with < 40% EF. Both groups showed normal response of global EF to exercise: mean rest EF was 40 +/- 14% and mean exercise EF was 45 +/- 14% (p < 0.01). When groups were considered separately, EF values showed the same behavior. Half of the patients showed normal response to exercise and the other half showed abnormal response. These changes were not associated with resting EF values, but were due to regional EF of lateral wall, that changed from 44 +/- 7 to 48 +/- 7% in the group of patients with normal LV EF response to stress and from 50 +/- 5 to 46 +/- 5% in those with abnormal response (p < 0.01).

Conclusion: The evaluation of regional ventricular EF by radionuclide ventriculography during exercise better discriminates functional reserve in patients with LV aneurysm than resting global EF. These findings could help the decision making of the therapeutic approach in this specific group of patients.