1.Introduction
A large amount of evidence indicates that more than one third of patients with coronary heart disease have myocardial ischemia. It is a worldwide clinical and public health problem. It is a risk factor for cardiovascular and cerebrovascular diseases and gradually becomes the cause of morbidity and death.
At present, early detection and disease monitoring of patients with CD, PET/CT scan, MRI, and cardiac magnetic resonance (CMR),The use of contrast agents[1] increases the burden on the patient’s heart, and even leads to an increase in patient mortality. Due to the high cost of MRI, Cardiac magnetic resonance (CMR) has many advantages in the structure of the heart, and it is sometimes used as the gold standard. Traditional electrocardiogram and ultrasound examination are not sensitive to the diagnosis of mankind. it is necessary to improve ultrasound as a routine early examination method for heart disease.
A 12-lead electrocardiogram (ECG) with a wave Giant Negative T Wave (GNT) on the anterior lead usually represents myocardial ischemia. GNT is defined as the T-wave depth of any lead ≥10mm, but it is not a myocardial ischemia There are various factors that lead to GNT, such as ADPM and malformation, due to the specific performance of blood. Sometimes clinical diagnosis will be misdiagnosed. Therefore, it is of great significance to find the cause of GNT in time. The characteristics of ECG in patients with apical hypertrophic cardiomyopathy (Ap HCM) also have T wave inversion, and HCM without coronary artery disease often shows symmetric T wave inversion on ECG. For several patients in this study, serum lipids, blood glucose levels, TET [2], and dynamic electrocardiogram were normal, and coronary angiography showed no obvious lumen stenosis. Therefore, we can rule out myocardial ischemia, combined with medical history, and coronary artery spasm. Possible; based on normal heart size, left ventricular wall motion and left ventricular ejection fraction, dilated cardiomyopathy (DCM) can also be excluded.
Under normal circumstances, myocardial cell repolarization is from the epicardium to the endocardium. The obvious T wave inversion may represent physiological changes during rapid ventricular repolarization. On the other hand, the T wave inversion may be due to hereditary heart muscle disease or it may be normal variation [3]. American scholars have pointed out that GNT is not a specific manifestation of apical hypertrophic cardiomyopathy. For example, in this study, the abnormal manifestation of papillary muscles is position shift to the apex (ADPM). ADPM is defined as the papillary muscle originating from the apical four-chamber view of the left ventricle near the apical segment of the third, regardless of whether it is associated with hypertrophy of the apical segment. We found that the number, shape, shape, and position of the papillary muscles vary considerably. According to Victor and Nayak’s research, in the anterior-lateral group of papillary muscles, only 1.5% of the papillary muscles originate from the middle and lower third [4].
This study confirmed for the first time the relationship between papillary muscle deformity and a downward shift with a huge inverted T wave and myocardial ischemia. However, the significance of 12-lead ECG and ultrasound imaging methods in the early detection of myocardial ischemia needs further study.
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