2D Echocardiography and complete ECG. (A) Continuous wave Doppler tracing of the LV mid-wall showed the peak pressure gradient was 85.5 mmHg at rest. (B) Subsequent continuous wave Doppler tracing eight hours later showed normal pressure gradient (estimated to be 5 mmHg). (C) In short axis view, apparently hypertrophied anterolateral and posteromedial papillary muscles together with a large, third accessory PM were observed (A: anterolateral papillary muscle, P: posteromedial papillary muscle, ACC: accessory papillary muscle). (D) Complete ECG showed prominent U wave in V1-V4.