Left ventricular hypertrophy

Introduction Left ventricular hypertrophy is proportional to the right ventricle, and the shape of the left ventricle is longer and more like a cone. Its cross section also presents an elliptical or nearly circular outline. The thoracic rib surface, the front of the heart, consists mainly of the right ventricle, and a small part is composed of the left ventricle. However, the left ventricle not only forms the apex, but also forms the majority of the septum of the heart, and the septum is the side of the organ that is in contact with the diaphragm. In order to pump blood out with a high blood pressure, the muscles of the left ventricle are thicker and more developed than the right ventricle.

Cause

There are several reasons for left ventricular hypertrophy, such as hypertension, coronary heart disease, hypertrophic cardiomyopathy, and valvular disease (such as aortic regurgitation). For example, in patients with high blood pressure, due to the increased pressure of the aorta, the left ventricle has to use a strong contraction force to pump blood into the aorta. The contractile force of the ventricle is completed by the electrical activity of the cardiac muscle fibers. Therefore, the strength of ventricular contractility is determined by the myocardium. As the pressure of the aorta increases, the original contractile force of the left ventricle can not pump enough blood into the aorta to meet the needs of the whole body. At this time, the myocardial cells can only proliferate, and the number of myocardium increases. Similar, and thus compensatory for ejection, the increase in the number of myocardium will make the left ventricle hypertrophy.

However, it is worth noting that the number of myocardium increases, but the contractile force is not significantly higher than before the increase, because the increased cardiomyocytes consume more energy when doing work, which increases the burden on the heart; The hypertrophy of the myocardium reduces the relative space of the ventricle, reduces the volume, and reduces the blood volume of one shot, and the intake score per minute is actually reduced. Therefore, in the long run, hypertrophy of the heart muscle does not improve the vicious circle of peripheral blood volume reduction in hypertensive patients.

an examination

Related inspection

Electrocardiogram two-dimensional echocardiography

ordinary inspection

Including blood biochemistry, electrolytes, urine routines, electrocardiograms, etc.

X-ray examination

Increased left ventricle, increased hilar shadow, pulmonary edema, and cloud-like shadows in the lungs.

Echocardiogram

1 Evaluation of cardiac function: systolic function and diastolic function.

2 found basic heart disease and other conditions that have an impact on heart failure.

other

Radionuclide examination, heart-lung oxygen exercise test, cardiac catheterization and coronary angiography.

Differential diagnosis

Differential diagnosis of left ventricular hypertrophy: hypertrophic cardiomyopathy: characterized by cardiac hypertrophy. According to the left ventricular outflow tract obstruction can be divided into obstructive (Obstructive) and non-obstructive (Non-obstructive) hypertrophic cardiomyopathy, asymmetry ventricular septal hypertrophy caused by aortic subvalvular stenosis called idiopathic hypertrophic Inferior stenosis coronary atherosclerotic heart disease: hypertrophic cardiomyopathy and coronary heart disease have angina pectoris, ECG ST-T changes, abnormal Q wave and left ventricular hypertrophy, so the two diseases are more easily misdiagnosed. Identification point:

1 murmur: hypertrophic obstructive cardiomyopathy can be detected in the lower left edge of the sternum or inside the apex of the jet systolic murmur. The lack of movement makes the noise increase, and the noise is weakened when the legs are raised. Can be accompanied by contraction fine tremor. Coronary heart disease with ventricular septal perforation or with papillary muscle dysfunction may also have systolic murmur. However, it is a reflux murmur.

2 coronary heart disease angina pectoris, containing nitroglycerin 3-5 minutes to relieve. Hypertrophic cardiomyopathy angina, nitroglycerin is ineffective, or even worse.

3 echocardiography, hypertrophic cardiomyopathy, ventricular septal thickness > 15mm, ventricular septal left ventricular posterior wall ratio > 1.5: 1. Coronary heart disease is mainly characterized by segmental wall motion abnormalities.

4 cardiac catheterization and coronary angiography can confirm the diagnosis. Aortic stenosis: The systolic murmur of aortic stenosis is mostly in the second intercostal space on the right sternal border, and the murmur is transmitted to the neck. Most of them are accompanied by systolic fine tremor, and the second heart sound of the aorta is weakened. X-ray examination of the ascending aorta has a stenosis and expansion, the two are not difficult to identify.

Ventricular septal defect: murmur is also in the lower left edge of the sternum, but for reflux murmur, echocardiography and cardiac catheterization can be clearly identified. Cardiac cell hypertrophy, increased extracellular matrix, increased myocardial oxygen consumption, increased myocardial fibrosis, and easily lead to myocardial ischemia and arrhythmia in left ventricular hypertrophy. Electrocardiogram and echocardiography can diagnose left ventricular hypertrophy.

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