2.1 Finalist criteria
This study is a retrospective observational study. To analyze the
clinical data of 215 cases of myocardial ischemia diagnosed in our
hospital from 2006 to 2018 due to the presence of GNT on the
electrocardiogram. After careful observation, combined with angiography
and echocardiography, 11 cases of clinical data with the characteristics
of Papillary muscle deformity downward movement(Male: female = 9: 2, age
46-73 years old), the average age is (59.5 ± 13.5) years old(Table 1).
Inclusion criteria: (1) According to the 2014 ESC ”Diagnostic
and Treatment Guidelines for Hypertrophic Cardiomyopathy”. ECG
examination: T wave asymmetry, of which 9 cases are: anterior myocardial
ischemia, and the patient has a 6-14 mm T wave inversion in leads V4-V6
(Figure 1-a/b). There are 2 cases of inferior wall ischemia. ECG tips:
sinus rhythm, normal ECG axis, 6-10mm T wave inversion (Figure 1-c/d),
no abnormal angiography, echocardiography shows left ventricular wall
structure, exercise, and left ventricular ejection fraction Within
normal range. (2) Coronary angiography results were normal. (3) Result
of left ventriculography: the left ventricle nipple is grossly deformed,
and its position is down. Echocardiography showed that the base of the
anterolateral papillary muscles(Figure 2)originated from the top third
of the left ventricle. At the same time, the combined medial papillary
deformity and downward movement showed a huge negative T wave,
corresponding to leads II, III,
and
Arterial vessel fistula. Eleven
patients had different degrees of discomfort in the precardiac area,
normal exercise tolerance, and left ventricular wall motion and left
ventricle ejection fraction were within normal ranges. The patient’s age
ranged from 1-73 years, with an average age of (59.5 ± 13.5) years. The
patient had no risk factors for coronary artery disease such as
hypertension, diabetes, and obesity, nor had a history of other
cardiovascular diseases, and was not given medication. Eleven patients
had normal physical examination, blood pressure remained within the
normal range of 70-90 / 110-125 mmHg, and the chest was not deformed.The exclusion criteria are: (1) There are other heart diseases;
(2) The spectrum of the heart cannot be accurately detected; (3) In
multiple examinations, the highest values of ECG, echocardiography,
coronary angiography and cardiac CT / MRI values are The difference of
the lowest value is greater than 3.
This study was approved by the Medical Ethics Committee of Liaoning
Provincial People’s Hospital of China Medical University.
2.2 Detection method:
Careful analysis of the medical history, laboratory data,
electrocardiogram, echocardiography, coronary angiography and cardiac CT
/ MRI of 11 patients. After further examination, blood lipids, blood
sugar, treadmill exercise test (spring games), 24-hour dynamic
electrocardiogram, coronary angiography were not abnormal,
echocardiography showed that the papillary muscles were close to the
apex (Figure 3). Echocardiographic evaluation: In this study, GE Vivid
E9 line echocardiography was used for general ultrasound and Sonove
sonography. Observe the levels of the apical four-chamber heart, apical
three-chamber heart, left ventricle and short-axis apical segment, and
at the same time try to avoid the short contraction of the left
ventricle in the horizontal section of the apical four-chamber.
Echocardiography showed that the base of the anterolateral papillary
muscles originated from the top third of the left ventricle(figure4). At
the same time, the medial papillary deformity and downward movement
after the merger showed a GNT, corresponding to leads II, III, and
Arterial vessel fistula. All 11 patients had varying degrees of
precordial discomfort, normal exercise tolerance, and left ventricular
wall motion and left ventricle ejection fraction were within the normal
range.
For the papillary muscles of healthy subjects, the left ventricular
papillary muscle is a tapered meat column that extends from the left
ventricular wall into the chamber. It is the muscle part of the mitral
valve device, which is always thick and paired, divided into The two
groups are located in the middle of the left ventricular cavity, in
which the anterolateral papillary muscles are located at the junction of
the anterior wall and the lateral wall of the left ventricle, and the
posterior medial papillary muscles are located in the posterior wall of
the left ventricle. The papillary muscles form a parallel arrangement
and no hypertrophy.
We found that the number, shape, shape, and position of the papillary
muscles vary considerably. The position of the papillary muscles has
moved down. American studies have pointed out that GNT is not a specific
manifestation of apical hypertrophic cardiomyopathy. In this study, the
abnormal manifestation of papillary muscles is position shift to the
apex. Apically displaced papillary muscle 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. 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 variation2. 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.
In the papillary muscles of healthy subjects, there are usually two sets
of anterolateral and posteromedial muscles of equal size in the left
ventricular cavity (Figure5). However, in this study, echocardiography
showed that 11 cases of anterolateral papillary muscle base originated
from 1/3 of the apex(Figure6), and 2 cases of posterior internal
papillary muscle base originated from the posterior and medial apex of
the left ventricle 1/3 (Figure 7) and some patients have morphological
variations in the papillary muscles, divided into multiple groups
(Figure8). The results showed that the position of the displaced, thick,
and grouped papillary muscles was consistent with the corresponding lead
changes of the conventional 12-lead ECG, and the corresponding rate was
more than 90%. After 5 years of follow-up, the patient’s ECG and
echocardiogram showed no abnormal changes and no cardiovascular events
occurred.
The presence of GNT in the differential diagnosis of electrocardiogram
GNT may indicate that the patient has apical hypertrophy, especially
when GNT is difficult to interpret, it must be taken into account, and
has certain predictive value. Apical hypertrophic cardiomyopathy is a
subtype of hypertrophic cardiomyopathy, which is limited to the apex of
the heart, and Japan accounts for about 24% [5,6]. Apical
hypertrophy is defined as the thickest part of the apical part ≥15mm,
and the ratio of the thickest part to the posterior wall ≥1.5. This is
the characteristic [7] of echocardiography in clinically suspected
apical hypertrophy [8]. Kobashi [9]and others believe that
papillary muscle hypertrophy is an early form of hypertrophic
cardiomyopathy. GNT can exist in single papillary muscle hypertrophy
[10,11]. Papillary muscle hypertrophy is defined as at least one
group of papillary muscles with a diameter ≥ 1.1 cm. Echocardiography is
the main method of diagnosing the disease, with a specificity of 90%,
but in our study, we found that two-dimensional echocardiography did not
show evidence of left ventricular hypertrophy.
At the same time, we know that the clinical manifestations depend on the
onset of emergency, mitral regurgitation, and primary disease. Mild
papillary muscle insufficiency that occurs gradually can be asymptomatic
due to its small effect on hemodynamics. In severe cases, palpitations,
shortness of breath, cough, fatigue, etc. may appear.
The purpose of this study was to compare the evaluation of myocardial
ischemia with 12-lead ECG and the evaluation of early myocardial
ischemia by combining multiple ultrasound imaging methods.