Cardiogenic syncope

Introduction Cardiac syncope is a syncope induced by cerebral ischemia caused by a sudden decrease in cardiac output. Severe cases can cause sudden death in the onset of syncope, which is the most serious type. The presence of organic heart disease is the most critical factor affecting the prognosis of patients with syncope. Patients with organic heart disease or left ventricular dysfunction should be highly alert to death if they experience syncope. According to foreign reports, the 1-year mortality rate (18-33%) of patients with cardiogenic syncope is significantly higher than that of non-cardiac syncope patients (0-12%) or unexplained syncope patients (6%). But this difference is mainly determined by the type of heart disease rather than syncope.

Cause

Cardiac syncope is a syncope induced by cerebral ischemia caused by a sudden decrease in cardiac output. Severe cases can cause sudden death in the onset of syncope, which is the most serious type. The presence of organic heart disease is the most critical factor affecting the prognosis of patients with syncope. Fallot tetralogy is the most common congenital heart disease caused by syncope; patent ductus arteriosus can cause syncope due to severe pulmonary hypertension; some patients with syncope are associated with ventricular tachycardia.

an examination

Related inspection

Cerebrospinal fluid glucose and serum glucose ratio dynamic electrocardiogram (Holter monitoring) human body weight balancer

Syncope occurs mostly during exercise or physical activity. Exercise causes peripheral vascular resistance to decrease and right ventricular outflow tract (funnel) to reflect paralysis, which increases right-to-left shunt and produces arterial hypoxemia resulting in syncope.

Most cardiogenic syncope is not related to body position (except for some special diseases such as atrial myxoma), and there are few prodromal symptoms. It can be accompanied by purpura, difficulty breathing, arrhythmia, weak heart sound and corresponding abnormal electrocardiogram. Heart diseases that cause cardiogenic syncope can be divided into three categories: arrhythmia, obstruction of cardiac output, and myocardial lesions.

Differential diagnosis

Coughing syncope:

Immediately after a severe cough, loss of consciousness, low muscle tone, and short duration. A small number of patients felt dizzy and dazzled, and their complexion changed from bruising to pale and sweating. Most of the patients were obese men after middle age, who often smoked and had bronchitis and emphysema. Children who developed pertussis or asthma also developed symptoms. Most after repeated coughing, occasionally fainted after a single cough, call, sneezing, yawning or laughing. Cough increases the intrathoracic pressure, causing venous return obstruction and cardiovascular reflex factors to play a role in the disease.

Simple syncope:

Also known as vasopressive syncope, vasovagal syncope. This is the most common type of syncope, accounting for about 90% of all syncope. There are often obvious incentives, such as nervousness, fear, anxiety, pain, seeing bleeding, and hearing bad news. Often occurring in frail young women.

Carotid sinus syncope:

It is a syncope caused by carotid sinus reflex allergy, and it is more common in men over 50 years old. The clinical manifestations are sudden necking, tight collar, or mild stimulation of the carotid sinus area, such as when shaving. But most episodes are spontaneous and there are no obvious incentives. More than standing, it appears as sudden dizziness, collapse, tinnitus, short duration, usually only 1 to 4 minutes, sometimes loss of consciousness, can be up to 20 minutes or so, rarely convulsions. There are three main types of clinical: (1) cardiac inhibition: with bradycardia as the main performance. (2) vascular inhibition type: mainly low blood pressure. (3) Brain type: mainly loss of consciousness.

Situational syncope:

It is one of the most common manifestations of syncope and is one of the most common manifestations of syncope. The reason why it is called episodic syncope is that the syncope episode must have a certain situation. The appearance of this kind of situation constitutes the condition of syncope, and similar scenes can cause multiple episodes of syncope, which is a predisposing factor for syncope. Situational syncope is more common in the elderly.

Labor syncope:

It suggests a cardiac outflow obstruction, mainly due to aortic stenosis. This syncope reflects cerebral ischemia caused by the simultaneous expansion of peripheral blood vessels due to the inability to increase cardiac output due to labor. Prolonged syncope can cause seizures. Low blood volume and positive inotropic drugs (such as digitalis) can aggravate outflow obstruction in patients with hypertrophic obstructive cardiomyopathy, and sudden syncope may occur. Syncope often occurs immediately after exercise because of reduced venous return, decreased left atrial pressure, and reduced ventricular filling. Arrhythmia may also be a contributing factor. Functional abnormalities after heart valve replacement may also be the cause. Labor syncope may also cause outflow obstruction due to other causes (such as pulmonary vascular occlusion or pulmonary hypertension caused by pulmonary embolism), and left ventricular filling or pericardial tamponade due to decreased left ventricular compliance, or venous return obstruction ( Such as severe pulmonary hypertension or tricuspid stenosis, caused by intracardiac myxoma. Myxoma can cause orthostatic syncope because the pedicled left atrial myxoma blocks the mitral valve opening. Coughing and urination can cause venous return to reduce syncope, and syncope can also occur when doing Valsalva action. The increase in intrathoracic pressure limits venous return, which reduces cardiac output and decreases systemic arterial pressure.

Syncope: refers to the sudden loss of transient consciousness caused by a sudden, transient, insufficient blood supply to the brain. It is caused by physical factors and can also be secondary to blood circulation disorders in the brain. Its clinical features are acute onset and loss of transient consciousness. Patients often have prodromal symptoms about one minute before the onset of syncope, manifested as general discomfort, blurred vision, tinnitus, nausea, pale, cold sweat, limb weakness, and soon syncope. At the onset of syncope, casual exercise and loss of sensation, sometimes apnea, slow heart rate, and even cardiac arrest, it is difficult to touch the radial artery and the carotid artery. Neurological examination can reveal dilated pupils, loss of light reflection and corneal reflexes, reduction or disappearance of sputum reflexes, pathological reflexes, often accompanied by salivation and urinary incontinence. It usually lasts for 2-3 minutes, and all functions are gradually restored. After the patient wakes up, there may be a short period of conscious turbidity, abdominal discomfort, nausea, vomiting, constipation, even incontinence, extreme fatigue, lethargy, duration of a few minutes to half an hour, after the onset of examination can be no positive signs.

The material in this site is intended to be of general informational use and is not intended to constitute medical advice, probable diagnosis, or recommended treatments.