This study has several limitations. First, the noninvasive screening tests used for diagnosis were not standardized. These authors used a battery of tests including ECG, echocardiography, 201Tl SPECT, gadolinium-enhanced MR scan, and endomyocardial biopsy. However, not all patients underwent all tests, making it unclear if cases of cardiac sarcoidosis were missed. Second, the study was retrospective, and it is unclear how aggressive the clinicians were in searching for symptoms of cardiac sarcoidosis in these patients. Third, it is problematic to use the criteria of The Japanese Ministry of Health and Welfare for the diagnosis of cardiac sarcoidosis26 in this study because those criteria predated the use of SPECT and cardiac MR scanning. For example, only three patients in group B received a diagnosis of cardiac sarcoidosis, and an additional three patients in this group received a diagnosis of another heart disease. However, a total of 12 patients in group B had abnormal cardiac MR scan results. Therefore, six patients with abnormal cardiac MR scans had no cardiac diagnosis. It is possible that these patients also had cardiac sarcoidosis. Nonetheless, the authors have provided ample evidence to support the premise that patients with symptomatic cardiac sarcoidosis have a poor prognosis and require detection and therapy.