RESUMO
The authors studied the cardiovascular effects of amitriptyline at therapeutic plasma concentrations in 15 depressed patients (6 M. 9 F.) without cardiovascular disease both before treatment and after six months of therapy. The cardiovascular effects were evaluated by means of electrocardiographic and 2D-echocardiographic examinations in basal conditions and after hand-grip stress test. The effects of isometric hand-grip exercise (IHG) on left ventricular size and performance were studied non invasively in all patients at rest and after 3 min. of IHG at 30% of maximum contraction. Left ventricular internal diameter was measured at end-diastole and end-systole on LV echograms, and blood pressure was measured by sphygmomanometer. Our data confirmed the depressant effect of amitriptyline even on healthy myocardium, an effect that becomes manifest only at handgrip stress with a significant reduction of ejection fraction (form 70.6 to 66.4%; p < 0.001), while ECG and arterial blood pressure did not change throughout the study. This goes to show that treatment with tricyclic antidepressants always has a latent depressant effect on myocardial contractility that becomes clinically evident under stress, as well as in subjects with heart disease and in the elderly. Hence the need to monitor left ventricular function, as well as ECG and blood pressure, and to exercise great caution in prescribing tricyclic antidepressants to subjects with a history of myocardial failure.