Presentations of Hypertrophic Cardiomyopathy on Myocardial Perfusion Imaging

The investigators will retrospectively evaluate myocardial perfusion patterns and cardiac function with Thallium (Tl)-201 gated dipyridamole MPI in patients with clinical diagnosis of HCM and patent coronary angiography between January 2013 and October 2016. The inclusion criteria included a spade-like configuration on left ventriculogram, or echocardiographic findings suggestive of HCM. The participants will be then divided into the following three groups: apical, concentric and septal forms. Regional perfusion would be analyzed using a 17-segment model from 0-4 degree (0=normal, to 4=absent perfusion); and summed stress score (SSS), summed rest score (SRS) and summed difference score (SDS) were calculated. Gated SPECT would be processed by quantitative gated SPECT (QGS) software (Cedars-Sinai Medical Center, Los Angeles, CA, USA) and ejection fraction phase analysis. Diastolic parameters would be also acquired by Doppler echocardiography, and correlated with MPI parameters.