RESUMO
Perioperative ventricular tachycardia (VT) was treated with nifekalant hydrochloride, a pure potassium channel blocker in 2 patients with low left ventricular ejection fraction (LVEF). The first patient is a 34-year-old woman, a chronic hemodialysis patient in whom severe aortic stenosis due to structural valvular deterioration of the previously implanted tissue valve was diagnosed with her LVEF of 26.9%. She underwent urgent redo aortic valve replacement with a mechanical valve. Postoperatively a sustained VT developed. After she received direct-current (DC) shock, nifekalant hydrochloride was administered. The 2nd patient is a 44-year-old man who presented with severe congestive heart failure. A coronary angiogram revealed triple vessel disease as well as decreased LVEF of 16% and ischemic mitral regurgitation. He underwent triple coronary artery bypass grafting and mitral ring annuloplasty. A VT developed requiring DC shock during hemostasis. Nifekalant hydrochloride was given immediately. In both patients, nifekalant hydrochloride was given intravenously in a dose of 0.3 mg/kg followed by a continuous intravenous infusion at a dose of 0.4 mg/kg/hr. Our experience shows nifekalant hydrochloride is effective against perioperative VT, especially in patients with impaired left ventricular function since it has mild positive inotropic effect.
