BIVENTRICULAR FUNCTION IN PATIENTS WITH NONISCHEMIC RIGHT VENTRICLE TACHYARRHYTHMIAS ASSESSED WITH MR-IMAGING

OBJECTIVE. The purpose of this study was to assess the value of MR ima ging in the evaluation of biventricular systolic and right ventricle d iastolic function in patients with nonischemic right ventricle tachyar rhythmias. SUBJECTS AND METHODS. Fifteen patients with nonischemic tac hyarrhythmias of right ventricle origin as documented by electrophysio logic testing and nine age-matched healthy volunteers underwent volume tric gradient-echo MR imaging of both ventricles to measure global sys tolic function. Patients and volunteers also underwent MR velocity map ping of transtricuspid flow to measure diastolic right ventricle funct ion. RESULTS. In the patient group, systolic function parameters of bo th ventricles were in the normal range. Tricuspid flow patterns indica ted a significant decrease in peak filling rate (p = .002) and in the slope of the descending part of the early filling phase (p = .009). Th e ratio of peak early filling rate to peak atrial contraction and rati o of integrated early filling to integrated atrial contraction (i.e., volume) were significantly lower in patients than in healthy volunteer s (p = .02 and p = .03, respectively). CONCLUSION. Diastolic right ven tricle function is significantly altered in patients with nonischemic tachyarrhythmias of right ventricle origin, but systolic function is p reserved. MR imaging is well suited to quantify abnormal right ventric le diastolic function, a possible marker of early cardiac disease.