부산대학교 도서관

Introduction: Takotsubo Cardiomyopathy (TCM) known as “Broken Heart Syndrome” is triggered by extreme emotional or physical stress. The typical TCM patient features chest pain, ST elevation, elevated troponin, reduced ejection fraction (EF), patent coronary artery, and apical ballooning.Hypothesis: Could abnormal coronary flow explain chest pain in Takotsubo patients?Methods: The patient with severe chest pain, elevated troponin, ST change, patent coronary arteries, and apical ballooning underwent angiography and review with a new dynamic recording technique. Ten patients without ACS, normal EF, and no coronary artery disease served as control. At first, the angiographic recording started when the contrast was injected into the coronary artery. Then the recording continued with the blood in white color moving in until all contrast disappeared from the arteries. The angiogram was recorded at 15 images per second. The review of coronary images focused on the blood flow in white on top of a background of black contrast. The arterial phase (AP) calculation began when the blood moved in and ended when all the contrast was flushed out of the distal arterial vasculature. The two-layer artificial intelligence program was built based on U-net and Densenet-121. The first layer, with a segmentation model and Convolutional neural network is responsible for detecting the starting frame of AP with a full index of contrast. The second layer with a segmentation model will detect the ending frame of AP. All TCM patient was followed up in one year.Results: Fifteen TCM patients met the criteria (12/15 female). The AP in the TCM group was 3.17 +/- 0.53 seconds compared with 1.62 +/- 0.26 seconds in the control group (P<0.001). The TCM group had a mean EF 33.9 +/- 7.6 %, and all recovered to 58.8 +/- 12.6 % after two weeks. At one year follow-up, all patients had no chest pain and no re-admission, except for one case of non-cardiovascular mortality associated with septic shock from pneumonia 3 months after the index event.Conclusions: Chest pain in TCM was caused by slow flow (measured as prolonged arterial phase) which was detrimental to myocardial contraction. Their prognosis was benign because all patients recovered.