[Biventricular pacing dramatically improved critical heart failure in idiopathic dilated cardiomyopathy: two case reports].

Two cases of dilated cardiomyopathy with intraventricular conduction delay, or left bundle-branch block and refractory heart failure, were markedly improved by biventricular pacing. The first patient's condition (Case 1) could not be improved despite administration of intravenous inotropic agents. He required mechanical ventilation and continuous hemodialysis as his condition worsened. Biventricular pacing was performed which was soon followed by increased blood pressure and decreased mitral regurgitation. As a result, mechanical ventilation, continuous hemodialysis and intravenous medication could be withdrawn. The second patient's condition (Case 2) deteriorated because of bradycardia due to advanced atrioventricular block. Unexpectedly, temporary right atrium-right ventricle sequential pacing increased mitral regurgitation and then caused heart failure, requiring a higher dose of inotropic and diuretic agents. Therefore, biventricular pacing was performed which rapidly improved both his symptoms and hemodynamic state, allowing reduction of the medication dose. Biventricular pacing dramatically improves critical conditions in patients in life-threatening states.