Syndrome X

Introduction to X syndrome X syndrome refers to symptoms of exertional angina or angina-like discomfort. The active plate ECG exercise test has evidence of myocardial ischemia such as ST-segment depression, while CAG shows a group of clinical syndromes with normal or non-obstructive coronary artery disease. basic knowledge The proportion of illness: the incidence rate is about 0.006% - 0.008% Susceptible people: no specific population Mode of infection: non-infectious Complications: unstable angina

Cause of X syndrome

(1) Causes of the disease

The cause of the disease is not fully understood, and the following three hypotheses are most commonly proposed: endothelium-dependent coronary dilatation due to decreased production of NO, increased sensitivity to sympathetic stimulation, and exercise-mediated crown Pulse contraction, but there is also growing evidence that these patients have increased pain sensitivity and analgesia.

(two) pathogenesis

Possible pathogenesis:

1. Insufficient coronary circulatory dysfunction or vasodilation reserve: There are many factors, such as senile, hypertension, diabetes and dyslipidemia, causing pathological changes in small coronary arteries, such as intimal hyperplasia and endothelial cell degeneration, causing microvascular endothelial cells Insufficient function, resulting in decreased endothelial-derived NO production, decreased blood flow-mediated microvascular dilatation, and decreased diastolic reserve capacity, which can cause myocardial ischemia. The evidence is: 1 when exercise or pacing induces chest pain, myocardial Increased lactic acid production, ECG with ischemic changes, UCG showed segmental wall motion and myocardial perfusion abnormalities, decreased LVEF, increased left ventricular end-diastolic pressure, decreased coronary resistance and decreased blood flow; 2 patient pairs The small coronary artery contraction response caused by vasoconstriction stimulation is increased, while the dilated vasculature effect of intracoronary injection of papaverine is weakened.

2. Increased sensitivity to sympathetic stimulation: Sympathetic sympathetic astigmatism can cause X syndrome. For example, when performing cardiac catheterization, some patients with X syndrome are usually sensitive to intracardiac device operation, direct stimulation The left atrium and infusion of saline cause typical chest pain.

3. Hyperalgesia: Some patients with syndrome X have no evidence of myocardial ischemia. The discomfort may be hyperalgesia. The feeling of chest pain is caused by arterial extension, heart rate, heart rhythm changes or changes in cardiac contractility. When the pain threshold is lowered, it can cause so-called allergic heart symptoms.

X syndrome prevention

Because patients often have anxiety and fear about chest pain, patiently explain the condition to the patient, help relieve symptoms, moderate physical activity, and physical exercise is also an effective treatment.

X syndrome complications Complications unstable angina

There is currently no relevant information to describe.

X syndrome symptoms common symptoms unstable angina anxiety chest pain depression rhomboid - phenomenon microvascular angina

Main symptoms

The main clinical manifestation of X syndrome is paroxysmal chest pain, which can be expressed as typical labor angina and atypical chest pain. It can be either stable angina or unstable angina, persistent resting type. Chest pain, ineffective for nitroglycerin, chest pain duration can be as long as 1 ~ 2h, a considerable number of patients induced physical activity threshold is not constant, can wake up in the early morning, and some patients show long lasting pain .

2. Other symptoms

Some patients with mild or no coronary disease who are overly concerned with their personal health due to chest pain may experience mental symptoms such as panic, anxiety and depression, accounting for two-thirds of patients with syndrome X.

Examination of syndrome X

Any laboratory test results have little diagnostic value for the diagnosis of syndrome X, but risk factors for coronary heart disease and secondary factors that cause angina can be found.

1. Blood lipids: There is sufficient evidence to prove that dyslipidemia is closely related to the pathogenesis of coronary heart disease. Therefore, all patients with suspected coronary heart disease should measure blood lipids. The typical lipid profiles of arteriosclerosis are: total cholesterol, low density lipoprotein, three The acylglycerol is elevated and the high density lipoprotein is decreased.

2. Blood sugar: Glucose tolerance and diabetes are risk factors for coronary heart disease. Therefore, patients with suspected coronary heart disease should check for fasting blood glucose to understand whether there is hyperinsulinemia.

Objective evidence of myocardial ischemia:

1.ECG: ECG is mostly in the normal range when there is no chest pain: a small number of patients may have mild ST-T changes, ECG may have ischemic ST-T changes in the onset of chest pain, active treadmill exercise test is positive, sometimes Hoher monitoring can also ST-T changes in myocardial ischemia were found, but some patients were unable to detect ECG ischemic changes during the onset of typical chest pain.

2.UCG: UCG examination is normal at rest, left ventricular segmental motor dysfunction can be seen when load-induced angina pectoris, but dipyridamole-loaded UCG can not detect signs of overall or segmental left ventricular dysfunction, but outside the heart When the large coronary artery lesions, it can induce segmental wall motion abnormalities, which can be used as one of the identification clues of X syndrome.

3. Motor nuclide myocardial perfusion scan: When exercise-induced angina pectoris, this examination can detect segmental myocardial perfusion reduction or defect and redistribution signs, radionuclide ventriculography can show left ventricular segmental motor dysfunction during exercise, EF Do not increase or decrease.

4. Coronary angiography (CAG): Patients with X syndrome had normal or no significant stenosis, ergometrine challenge test negative, no abnormal left ventricular angiography, no cardiac enlargement or signs of cardiac hypertrophy, left ventricular end-diastolic pressure Generally normal.

Diagnosis and differentiation of syndrome X

Diagnostic criteria: typical labor angina pectoris, ECG with myocardial ischemia or atypical chest pain, exercise test positive, ventricular function and CAG showed normal coronary artery and ergometrine challenge test, when having the above When it is clinically confirmed as X syndrome.

Syndrome X should be differentiated from other diseases that cause chest discomfort.

Esophageal disease

(1) reflux esophagitis: due to relaxation of the lower esophageal sphincter, acidic gastric reflux, causing esophageal inflammation, paralysis, manifested as burning pain in the posterior sternum or mid-upper abdomen, sometimes can be radiated to the back and suspected angina, but the disease It usually occurs when lying down after a meal, and it can be relieved by taking an antacid.

(2) esophageal hiatus hernia: often accompanied by acid reflux, the symptoms are similar to esophagitis, often after bending or lying down after a meal, gastrointestinal angiography can be clearly diagnosed.

(3) diffuse esophageal fistula: can also be associated with reflux esophagitis, which can cause a variety of chest pain, taking nitroglycerin is effective, ergometrine can be induced, it is easy to suspect angina pectoris, is atypical angina A common cause of chest pain, according to the patient's history of acid reflux and anorexia, symptoms often occur when eating especially cold drinks or after meals, not related to fatigue, dysphagia at the time of onset can be distinguished from angina, esophagoscopy and esophageal manometry The law can be clearly diagnosed.

Clinically, angina pectoris and esophageal diseases often coexist, esophageal reflux can reduce the threshold of angina pectoris, esophageal fistula can be induced by ergometrine and relieved by nitroglycerin, so the identification of the two is often difficult, chest pain is "burning heart", and It is related to postural changes and eating. At the same time, dysphagia is a characteristic of esophageal pain. Esophageal pain is more common than angina to the back. Accurate diagnosis requires not only careful medical history and physical examination, but also laboratory examination.

2. Lung, mediastinal disease

(1) Pulmonary embolism: its pain suddenly occurs and occurs at rest. Patients with high risk factors (such as heart failure, venous disease, postoperative surgery, etc.) are often accompanied by hemoptysis and shortness of breath. The painful nature is typically It is described as a chest tightness accompanied by or subsequent pleural inflammatory chest pain, that is, the side of the chest is sharp and painful, breathing or coughing makes it worse, X-ray chest X-ray, pulmonary angiography, pulmonary radionuclide scan can be clearly diagnosed.

(2) spontaneous pneumothorax and mediastinal emphysema: both chest pains occur suddenly, the former chest pain is located on the side of the chest, the latter is located in the center of the chest, accompanied by acute dyspnea, X-ray chest can be clearly diagnosed.

3. biliary colic

The disease often occurs suddenly, the pain is severe and often fixed, lasting 2 to 4 hours, then disappearing on its own, without any symptoms during the interictal period, generally it is the heaviest in the right upper abdomen, but it can also be located in the upper abdomen or pre-cardiac region. This discomfort often radiates to the scapula, can be radiated to the back along the costal margin, and occasionally radiates to the shoulders, suggesting that the diaphragm is stimulated, often nausea, vomiting, but the relationship between pain and meals is uncertain; Indigestion, abdominal flatulence, can not tolerate fat food and other medical history, but these symptoms are also common in the general population, the specificity is not strong, ultrasound imaging is accurate for the diagnosis of gallstones, and can understand the gallbladder size, gallbladder wall thickness and whether there is Bile duct dilatation, oral gallbladder angiography failed to show gallbladder filling, suggesting that the gallbladder is not functional.

4. Causes of nerves, muscles and bones

(1) Cervical radiculitis: It can manifest as persistent pain, sometimes causing sensory disturbances. Pain may be related to neck activity. Just as shoulder joint activity causes bursitis pain, the fingers are pressed along the back and have skin allergies. Area, suspicious and thoracic radiculitis, sometimes, cervical rib compression arm and shoulder plexus can produce angina-like pain, physical activity can also be found in the shoulder joint inflammation and / or shoulder ligament calcification, cervical spondylosis, similar to angina Musculoskeletal disorders, bursitis under the shoulders and costal cartilage.

(2) thoracic rib syndrome: also known as Tietze syndrome, the pain is limited to the cost of the costal cartilage and rib sternal joint swelling, tenderness, clinical manifestations of typical Tietze syndrome is not common, and costal cartilage inflammation caused by ribs and costal cartilage The tenderness (without swelling) is relatively common. At the time of examination, tenderness at the junction of the costal cartilage is a common clinical sign. Treatment of costal cartilage usually involves the elimination of doubts and anti-inflammatory drugs.

(3) Herpes zoster: chest pain may occur in the early stage of rash, and may even resemble myocardial infarction in severe cases. According to the persistence of pain, it is limited to the distribution area of skin sensory nerve fibers, the skin is extremely sensitive to touch and specific herpes. A diagnosis can be made that can make this disease.

(4) Unexplained chest wall pain and tenderness: palpation and chest activity (such as bending over, turning or swinging the arm while walking) can cause chest pain, contrary to angina pectoris, the pain can last for a few seconds or hours, nitroglycerin can not It is immediately relieved, generally does not require treatment, and even requires salicylate.

5. Functional or mental chest pain

It is a manifestation of anxiety in the circulatory debilitation. The pain can be located at the apex of the heart. It is a pain that lasts for several hours. It often aggravates or changes to a sharp scalp under the breast for 1 to 2 s. When tension and fatigue, there is little relationship with exercise, which may be accompanied by tenderness in the precordial area. It may be accompanied by palpitations, hyperventilation, numbness and tingling of the limbs, sigh, dizziness, difficulty breathing, general weakness and emotional instability or depression. Other signs, except for analgesics, can not be alleviated, but can be alleviated by various forms of intervention, such as rest, labor, tranquilizers and placebo. In contrast to myocardial ischemic pain, functional pain is easier to display. Different responses to different interventions, because functional pain often occurs after hyperventilation, the latter can cause increased muscle tone, resulting in diffuse chest tightness, some so-called functional chest pain may actually have organic The basis of the disease, which is common in patients with mitral valve prolapse, and the nature of chest pain varies greatly between patients, which is similar to typical angina. Chest pain is similar to the previous cycle of debilitating neurological disease.

6. Non-coronary atherosclerotic heart and vascular disease

(1) acute pericarditis: the age of onset is mild, often has a history of viral upper respiratory tract infection, the pain caused by inflammation is sudden onset, sharper than angina pectoris, position is leftward rather than in the middle of the chest, often radiating to the neck The pain is persistent and unrelated to fatigue. Breathing, swallowing and twisting the body can make it worse. When the patient sits up and leans forward, the pain is relieved. Auscultation has a pericardial friction sound, which can be clearly diagnosed by means of an electrocardiogram.

(2) Aortic disease: When there is sudden and severe pain in patients with high blood pressure, and the radiation to the back and waist, the possibility of aortic dissection is revealed; the continuous expansion of the thoracic aortic aneurysm can erode the limitation of the vertebral body. Severe drilling-like pain, especially at night; severe aortic stenosis due to insufficient coronary blood supply, angina can occur, systolic murmur in the aortic valve area and echocardiography can be identified.

(3) severe right ventricular hypertension: mitral stenosis, primary pulmonary hypertension and pulmonary heart disease can cause pain, this pain can also occur when pulmonary artery pressure, such as severe pulmonary stenosis with right ventricular hypertension, is currently considered The pain is due to limited cardiac output. In the systolic phase, coronary blood flow is reduced due to right ventricular hypertension, and oxygen consumption in the right ventricle is increased, resulting in poor myocardial perfusion. Therefore, chest discomfort can be caused by cardiac ischemia. The pain can be relieved by itself, and it lasts for a few minutes. Therefore, the reaction to nitroglycerin is difficult to evaluate. If the pain is caused by activity and can be prevented by nitroglycerin, the pain is likely to be caused by coronary heart disease. Many patients with pulmonary hypertension are exercising. ST segment shift occurs on the electrocardiogram after exercise.

(4) Chest angiography results of normal chest pain: angina pectoris or chest pain similar to angina pectoris with normal coronary angiography syndrome is often called X syndrome, need to distinguish from typical ischemic heart disease caused by coronary heart disease, the cause It is unclear that some of these patients have true myocardial ischemia, which is characterized by increased lactate production in the heart muscle during exercise or rapid pacing.

Studies have shown that many patients with syndrome X have microvascular and / or endothelial dysfunction, clinical chest pain can be accompanied by myocardial ischemia, but some patients can not find any evidence of myocardial ischemia clinically, this Some patients often have behavior, mental disorders or esophageal dysfunction (expressed by the injection of hydrochloric acid in their esophagus can cause pain recurrence), indicating that chest pain symptoms can be completely non-cardiac, and now think that patients with normal coronary angiography can have chest pain. Caused by a variety of abnormal conditions: due to microvascular dysfunction caused by ischemia caused by ischemia, called microvascular angina; chest discomfort without ischemia can be hyperalgesia; chest pain is the feeling of arterial extension, heart rate, heart rhythm or Changes in cardiac contractility stimulate the heart; sympathetic predominance sympathetic astigmatism can cause X syndrome. When performing cardiac catheterization, some patients with X syndrome are usually sensitive to intracardiac device operation, directly stimulating the right atrium and Infusion of normal saline can cause typical chest pain, and some patients can also have microvascular dysfunction and painfulness. Min, the pathological changes of coronary vessels in patients with syndrome X are inconsistent: in some patients, the small coronary arteries have intimal thickening or atherosclerotic plaque, while in some patients the coronary arteries are completely normal.

Patients with chest pain and normal coronary angiography are more common in premenopausal women. Most of the symptoms of chest pain are not typical. Chest pain can be induced by fatigue, but the threshold of pain is very variable. Sometimes the pain is very severe. This disease can affect the disease. The patient's work and quality of life, some patients may have panic, anxiety or mental abnormalities and other clinical manifestations, some patients have insulin resistance and hyperinsulinemia, clinical examinations and more abnormal findings, some patients may have non-special ECG on chest X-ray Heterosexual ST-T wave abnormalities, nearly 20% of patients have positive exercise test, and motor nuclide myocardial imaging can be found in some patients with myocardial perfusion abnormalities, but it has no consistent correlation with defect range, exercise test positive degree and exercise tolerance. .

Compared with patients with angina pectoris caused by coronary atherosclerosis, the prognosis of syndrome X is usually very good, and there is no significant difference from the normal population.

For patients with clinical evidence of ischemia, nitrate and -blockers can be used, but the actual treatment effect is often unsatisfactory. Nitrate can not improve the exercise tolerance of patients with syndrome X, and even some patients Exercise tolerance, calcium antagonists can reduce the frequency and severity of chest pain in some patients, and can improve their exercise tolerance, in the course of treatment should try to find non-cardiac causes of chest pain, have gastric-esophageal reflux and esophageal function Disorders, treatment of these diseases is effective in relieving symptoms, and those who have no evidence of ischemia and/or those who are not responding to ischemic treatment, in addition to providing general supportive care, patiently explain the good prognosis of the disease to the patient, so that Peace of mind is also an important part of treatment.

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