Evaluation of radionuclide angiography in diagnosis of arrhythmogenic right ventricular cardiomyopathy

The accuracy of Fourier analysis of radionuclide angiography for the diagnosis of arrhythmogenic right ventricular cardiomyopathy was assessed versus X-ray right ventricular angiography. In patients with recurrent right ventricular tachycardia, the diagnosis of arrhythmogenic right ventricular cardiomyopathy is based on the presence of right ventricular wall motion abnormalities on conventional X-ray angiography without evidence of other heart disease. X-ray and radionuclide angiography were prospectively compared in 73 patients with ventricular tachycardia. We analyzed the presence of a right ventricular enlargement, global hypokinesia and segmental wall motion abnormalities, using visual analysis for both techniques and Fourier analysis for radionuclide angiography. Disease was noted as absent or present and as diffuse or localized. The interobserver reproducibility of both techniques for the diagnosis of right ventricular wall motion abnormalities was tested in 27 randomly selected patients. According to X-ray angiography, 53 patients were considered to have arrhythmogenic right ventricular cardiomyopathy (22 diffuse, 31 localized forms) and 20 patients a normal right ventricle. The sensitivity of radionuclide angiography was 94.3%, specificity 90% and positive and negative predictive values 96% and 85.7%, respectively. Agreement for the location of the wall motion abnormalities was 60% for the apex, 76% for the outflow tract, 82% for the inferior wall and 74% for the free wall. The diagnostic interobserver reproducibility of X-ray and radionuclide angiography was 74% and 96.2%, respectively. In a selected cohort, Fourier analysis of radionuclide angiography is an accurate and reproducible tool for the diagnosis of arrhythmogenic right ventricular cardiomyopathy.