Symptom >> Internal Medicine >> Cardiology

Low pulse pressure

Introduction
Cause
Examine
Diagnosis

Introduction

Introduction Blood pressure refers to the pressure on the side walls of blood vessels when blood flows. Blood pressure is divided into systolic and diastolic blood pressure, and the difference between systolic blood pressure and diastolic blood pressure is called "pulse pressure difference". For example, the systolic blood pressure is 120 mm Hg, the diastolic blood pressure is 80 mm Hg, and the pulse pressure difference is 40 mm Hg. Under normal circumstances, the normal person's pulse pressure difference is 30-40 mmHg, if the pulse pressure difference is less than 30mmHg, it can be determined that the pulse pressure difference is small. The pulse pressure difference is too low to be seen in patients with early hypertension. Pulse pressure reduction is common: low blood pressure, pericardial effusion, severe mitral stenosis, severe heart failure and other diseases.

Cause

Cause

Due to the increased sympathetic excitability of the patient, the small blood vessels in the whole body are paralyzed, so that the systolic blood pressure is not high, the diastolic blood pressure is relatively increased, and the pulse pressure difference is small. Pulse pressure difference is small physiological and pathological, physiological factors are generally due to physical weakness and weakness, pathological factors such as myocardial infarction, cardiac insufficiency, pericardial stenosis, aortic stenosis, pericardial effusion, contraction Narrow pericarditis, severe mitral stenosis, severe heart failure, peripheral circulatory failure, shock, etc.

It is generally believed that aortic and other large atherosclerosis, decreased elasticity and extensibility of the arterial wall, are caused by increased blood pressure in the simple systolic phase. The stiffness of the aorta causes the pressure wave to be reflected faster, causing the superposition of the reflected waves to advance to the systolic phase, resulting in a higher systolic pressure wave. When diastolic, the aorta does not have enough elastic retraction to maintain diastolic blood pressure, which causes diastolic blood pressure to decrease, and the pulse pressure difference increases. Common diseases are: essential hypertension, aortic regurgitation, aortic sclerosis, hyperthyroidism, severe anemia, rheumatic heart disease, syphilitic heart disease, partial congenital heart disease and hypertensive heart disease, bacteria Endocarditis and the like.

Examine

an examination

Related inspection

Blood pressure ambulatory blood pressure monitoring (ABPM)

Measuring the pulse pressure, if the pulse pressure difference is less than 30mmHg, it can be determined that the pulse pressure difference is small, if you want to diagnose the disease, you need to check the body, instrument detection, for further diagnosis.

Indirect measurements are used for the measurement of human arterial blood pressure, usually using the assay invented by the Russian physician N. Korotkov. The device consists of an inflatable cuff and a pressure gauge connected to it, and the sleeve is tied to the subject. The upper arm, then pumping to block the blood flow of the brachial artery, slowly release the air inside the cuff, using the stethoscope placed on the radial artery can be heard when the cuff pressure is just less than the brachial blood pressure, the blood flow is over the flattened The vibrational sound caused by turbulence in the arteries (Krottkov, referred to as Coriolis sound) is used to determine the highest pressure during systole, called systolic blood pressure. Continue to deflate, the Coriolis sound increases, and the blood pressure reading measured when the sound becomes low and long is equivalent to the lowest blood pressure at the time of diastole, called diastolic blood pressure, when the deflation into the cuff is lower than the diastolic pressure. At the same time, the blood flow smoothly through the unobstructed blood vessels, and the Coriolis sound disappears.

Because the specific gravity of mercury is too large, it is difficult for the mercury manometer to accurately and quickly reflect the instantaneous changes of blood pressure in each phase of the heartbeat. Therefore, various sensitive membrane manometers can be used to accurately measure the contraction and diastolic blood pressure. In recent years, various transducers have been used in combination with an oscilloscope to more sensitively measure blood pressure.

National authorities issued: normal blood pressure: systolic blood pressure <130mmHg, diastolic blood pressure <85mmHg, ideal blood pressure: systolic blood pressure <120mmHg, diastolic blood pressure <80mmHg.

(1) X-ray examination: the left heart is round and the heart is not big. Common aortic stenosis and aortic calcification. In the absence of calcification in the adult aortic valve, there is generally no severe aortic stenosis. In the heart failure, the left ventricle is obviously enlarged, and the left atrium is enlarged, the pulmonary artery is prominent, the pulmonary vein is widened, and the signs of pulmonary blood stasis are seen.

(2) Electrocardiogram examination: The electrocardiogram of the patients with mild aortic stenosis can be normal. Severe ECG left ventricular hypertrophy and strain. The increase in ST segment depression and T wave inversion suggests that ventricular hypertrophy is progressing. The performance of left atrial enlargement is more common. When the aortic valve calcification is severe, left anterior branch block and other various degrees of atrioventricular or bundle branch block can be seen.

(3) Echocardiography: M-mode ultrasound showed thickening of the aortic valve, the amplitude of the activity was reduced, and the opening range was less than 18 mm. The enhancement of the reflected light spot of the leaflets suggested valvular calcification. Aortic root dilatation, left ventricular posterior wall and ventricular septal symmetry hypertrophy. On the two-dimensional echocardiogram, the aortic valve systolic phase showed a concentric tangential motion and could identify congenital valvular malformations. Doppler ultrasound shows a slow and decreasing blood flow through the aortic valve and can calculate the maximum transvalvular pressure gradient.

(D) left heart catheterization: direct measurement of left atrial, left ventricular and aortic pressure. The left ventricular systolic blood pressure increased, the aortic systolic blood pressure decreased, and the pressure gradient increased as the aortic valve stenosis worsened. The pressure curve of the left atrium contracted was a high a wave. Should be considered in the following cases: young patients with congenital aortic stenosis, although asymptomatic but need to understand the degree of left ventricular outflow obstruction; suspected left ventricular outflow obstruction rather than valve causes; to distinguish aortic stenosis Whether combined with coronary artery disease, coronary angiography should be performed at the same time; multivalvular disease before surgery.

The pulse pressure difference for no discomfort is small, and it is not necessary to be too mindful because it does not have much influence on health.

Diagnosis

Differential diagnosis

Differential diagnosis:

There are many diseases that cause small pulse pressure difference, and it is generally necessary to identify:

When the pulse pressure difference is significantly reduced, if a clear cause is not found, it should be considered to be a decrease in constitutional blood pressure (mainly systolic blood pressure). To treat constitutional hypotension, in addition to enhancing physical fitness and proper nutrition, it is also necessary to prevent dizziness or falls when standing. It can be treated with drugs such as oryzanol and vitamins which regulate the action of autonomic nerves.

The following diseases require further diagnosis:

1 myocardial infarction

According to typical clinical manifestations, characteristic ECG changes, and laboratory tests, it is not difficult to diagnose the disease. A painless patient is more difficult to diagnose. All elderly patients suddenly have shock, severe arrhythmia, heart failure, upper abdominal pain or vomiting, and the cause is unknown, or the original hypertension and sudden drop in blood pressure and no cause can be found, shock occurred after surgery but excluded For reasons such as bleeding, the possibility of myocardial infarction should be considered. In addition, elderly patients have heavier and longer-lasting chest tightness or chest pain. Even if there is no characteristic change in ECG, the possibility of this disease should be considered. All should be treated according to acute myocardial infarction, and electrocardiogram observation and serum myocardial enzyme assay should be repeated in a short period of time to determine the diagnosis.

2 aortic stenosis