Objective: Arrhythmogenic right ventricular disease (ARVD) is increasingly found in young adults with ventricular arrhythmias and is characterized by ventricular tachycardia originating within the right ventricle and regional or diffuse abnormalities in the contraction of the right ventricle. Until now, the gold standard for the detection of global and regional abnormalities of the right ventricular wall has been angiography combined with biopsy. The purpose of the current study was to compare MR imaging with angiography for assessing the location and extent of morphologic and functional abnormalities in patients with ARVD.
Subjects and methods: Electrocardiographically gated spin-echo and cine gradient-echo MR imaging of the heart was performed in 36 consecutive patients with biopsy-proved ARVD. Patients were prospectively separated into two groups according to the results of invasive electrophysiologic tests (18 with inducible ventricular tachycardia during invasive electrophysiologic studies [ARVD 1] and 18 without inducible ventricular tachycardia [ARVD 2]) and compared with 11 control subjects. Global and regional morphology and function of the right ventricle were assessed with MR imaging, and those findings were compared with angiographic findings.
Results: Right ventricular ejection fraction was significantly lower in patients with ARVD 1 than in patients with ARVD 2 or in control subjects. Regional abnormalities of the right ventricular wall also were more pronounced in patients with ARVD 1 than in patients with ARVD 2. Signal-intensity increases corresponding to fatty replacement shown by biopsy were seen in 33% of patients with ARVD 1 and in 11% of patients with ARVD 2. Abnormal regions of the right ventricular wall seen on MR images corresponded to angiographic findings in 86% of patients. Comparison with control subjects showed that patients with ARVD 1 had a significant delay in diastolic relaxation of the right ventricle.
Conclusion: Our results show that MR imaging can be used to assess morphologic alteration, tissue abnormalities, and global as well as regional dysfunction of the right ventricle in patients with ARVD. It may become a useful clinical tool for diagnosing and grading ARVD and a worthy substitute for angiography and biopsy in the follow-up of patients with ARVD.