Patients with depression have increases risk of cardiac mortality. Overdose with venlafaxine has been accused of supraventricular tachycardia, atrial fibrillation and other cardiac effects. Discontinuous and inhomogeneous propagation of sinus impulses in atrium plays a major role in atrial fibrillation. We aimed to measure the effects of venlafaxine therapy on propagation of sinus impulses reflections in electrocardiography in depression. Eligible 19 participants were outpatients with depression. 75 mg/day dose of venlafaxine was administered to the patients. The patients were asked to complete both Beck Depression and Anxiety Inventories. 17 healthy participants enrolled in the study. The electrocardiography records were obtained while patients were drug naive and one week after treatment. The baseline durations of P(minimum) and P(maximum) in the patient group were significantly shorter than controls (p < 0,05). The differences between baseline and after venlafaxine therapy among electrocardiographical variables were statistically insignificant. There were no significant correlations between age, sex, body mass index, clinical inventories and electrocardiographical variables in both patients and controls. Autonomic dysregulation in myocardium is still inconclusive in depression. Venlafaxine at therapeutic dose of 75 mg/day does not seem to be associated with myocardial conduction dysregulation.