Effect of imipramine and nortriptyline on left ventricular function and blood pressure in patients treated for arrhythmias

Abstract

The effect of imipramine or nortriptyline on left ventricular function and orthostatic blood pressure was evaluated in 20 nondepressed cardiac patients treated for ventricular premature depolarizations (VPDs). Drug was administered by mouth and dose ranging used, 1 mg/kg/day (imipramine) or 0.5 mg/kg/day (nortriptyline), was increased after four doses (imipramine) or six doses (nortriptyline) until >80% suppression of VPDs or adverse effects occurred or until a maximum dose of 5 mg/kg/day (imipramine) or 3.5 mg/kg/day (nortriptyline) was given. Fourteen (70%) had >80% VPD suppression, five had <80% improvement (range 25% to 77%), and one had a VPD frequency increase of 6%. Mean daily imipramine dose was 210 ± 103 mg and mean nortriptyline dose was 100 ± 29 mg. Neither drug significantly changed mean ejection fraction or peak systolic pressure end-systolic volume ratio by radionuclide angiogram. Both reduced standing systolic blood pressure: mean change after imipramine was 26 mm Hg (NS), and after nortriptyline, 14 mm Hg ( p < 0.05). Drug was discontinued in two patients because of symptomatic orthostatic blood pressure change > 30 mm Hg. There was not a significant relationship between dose, drug concentration, or functional class and orthostatic change in systolic blood pressure but there was for age ( p < 0.05). These observations suggest that even cardiac patients with impaired systolic function may take imipramine or nortriptyline for VPDs; however, frequent blood pressure measurement is advised, particularly in older patients.