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.
2.