What Is Sick Sinus Syndrome?

Sick sinus syndrome (SSS) Synonyms: sick sinus syndrome, dull sinus syndrome, sinus syncope, inert sinus node

Sick sinus syndrome

Sick sinus syndrome (SSS) is referred to as sick sinus syndrome. It is a complex disorder of a variety of arrhythmias and symptoms caused by sinus node atrial impulse formation, or sinus node to atrial impulse conduction disorder due to the original organic lesions of the sinoatrial node or its surrounding tissues. The main feature is sinus bradycardia, which is called bradycardia-tachycardia syndrome when recurrent tachyarrhythmia occurs. Symptoms are mostly seen in people over 40 years of age.

Sick sinus syndrome (SSS) Synonyms: sick sinus syndrome, dull sinus syndrome, sinus syncope, inert sinus node

Part: Chest

Department: Cardiology, Cardiothoracic Surgery

Related symptoms: headache, palpitations, heart failure, arrhythmia, dizziness, syncope

Examination: Ambulatory ECG (Holter monitoring), Ultrasound diagnosis of cardiovascular disease, Echocardiography

Causes of Sick Sinus Node Syndrome

Idiopathic sclerosis-degenerative changes, coronary heart disease, cardiomyopathy, myocarditis, rheumatic heart disease, surgical injury, hypertension, etc.

Clinical manifestations: Onset and insidious attack, slow progress, sometimes found by accident. Can be persistent or intermittent. When a high degree sinus block or sinus arrest occurs, short-term syncope or dark haze can occur. Occasionally angina, heart failure or shock can occur. Acute inferior myocardial infarction and myocarditis can cause temporary sinus node dysfunction, which usually disappears after the acute phase.

Examination: (a), electrocardiogram (b), measurement of sinoatrial node function

Treatment: 1. Etiology treatment. 2. medical treatement. 3 Install an on-demand artificial pacemaker.

Classification of sick sinus syndrome

Geriatrics

Clinical manifestation

Clinical manifestations vary, and may be intermittent. Insufficient blood supply to the brain, heart, kidney and other organs caused by slow heart rate, especially cerebral blood supply insufficiency. People with mild fatigue, dizziness, dizziness, insomnia, poor memory, slow response or irritability are easily misdiagnosed as neurosis, and the elderly are also misdiagnosed as cerebrovascular accident or aging syndrome. Severe cases can cause transient darkening, near syncope, syncope, or Asthma Syndrome. Some patients with short-onset supraventricular tachyarrhythmias, also known as slow-fast syndrome. During the onset of tachyarrhythmia, the heart rate can suddenly accelerate up to 100 beats / min or more, and the duration varies. Sudden tachycardia may be followed by a cardiac apnea with or without syncope. In addition to palpitations caused by severe bradycardia or tachycardia, it can also aggravate the symptoms of existing heart disease and cause heart failure or angina. Low cardiac output severely affects perfusion of organs such as the kidneys and can cause oliguria and indigestion. Slow syndrome may also cause symptoms of vascular embolism.

Symptoms and signs of sick sinus syndrome

The disease is based on a sustained slow rhythm, with occasional onset of sinus arrhythmias. Compared with middle-aged and young people, elderly patients have the following characteristics: Double-nodular lesions are more common, sinus node disease causes significant sinus bradycardia, sinus house group 4 and sinus stagnation, based on this, such as borderline escape beats Appearing later (2s) or borderline escape rhythm is slow (<35 beats / min or with AV block), indicating that the disease involves the sinoatrial node and the atrioventricular node, which is called double-node disease. Elderly There are significantly more double-knot lesions in humans than in young and middle-aged people, suggesting that elderly patients have extensive lesions and serious conditions. Slow-fast syndrome is common: elderly patients are more likely to have transient tachyarrhythmia (supraventricular tachycardia) based on sustained slow rhythm. , Atrial flutter, atrial fibrillation), indicating atrial lesions, such as accompanied by atrioventricular or bundle branch block, suggesting the entire conduction system lesions. Heart, brain and kidney ischemia is more prominent: heart rhythm <40min, often with organs Symptoms of inadequate blood supply include fatigue, dizziness, dizziness, insomnia, memory loss, sluggishness, and severe asthma.

Causes of Sick Sinus Node Syndrome

Coronary heart disease was previously considered to be the most common cause of the disease, and recently the elderly sinus node and its surrounding tissues were considered to be the most common cause of the disease (> 50%), followed by coronary heart disease (<25%>, other rare causes). There are myocarditis, cardiomyopathy, myocardial amyloidosis and connective tissue diseases.

Pacemaker and conducting cells in the elderly cardiac conduction system. Decline decreases with age. Replace it with stretch. Reticulum and collagen fibrous tissue increased. As well as fatty infiltration and calcification. The range of lesions can be part or all of the conduction system. This is the pathological basis of sick sinus syndrome in the elderly. The disease is mainly a lesion of sinoatrial node P cells and surrounding fibers. Sometimes wider. Involves the atrium or atrioventricular junction. The latter is also called double knot disease. Common causes are: coronary heart disease: the most common cause of sinus syndrome in the elderly. The sinoatrial node blood supply comes from the central artery of the sinoatrial node. 55% of this arterial blood supply comes from the right coronary artery. 45% come from the circumflex branch of the left coronary artery. Because the sinoatrial node has only one artery to supply blood. So when coronary atherosclerosis affects the artery. The sinoatrial node will have ischemic changes. Acute myocardial infarction, especially inferior posterior wall infarction. Bradycardia can occur in more than half of patients. Caused by chronic coronary artery poor blood supply. It is mostly a chronic process. Progressive increase. However, some studies have found that the sinoatrial node arteries of patients with diseased sinus syndrome with coronary atherosclerosis are often not diseased. Sinus syndrome does not exceed 25% of patients with clinically confirmed coronary heart disease. Myocardial infarction can occur in addition to acute inferior and lateral infarctions. It's not common. And it is often temporary. Therefore, it is suggested that there may be other more important factors involved in the pathogenesis of this disease. At present, the most common basic disease of the elderly is caused by the degenerative changes and sclerosis of the sinoatrial node and its adjacent tissues with age. Myocarditis and cardiomyopathy: another common cause of sick sinuses in China. Such as rheumatic and viral myocarditis. Systemic lupus erythematosus. Cardiomyopathy and primary cardiomyopathy caused by amyloidosis. Trauma. Heart surgery and radiation therapy can cause sinus node dysfunction when it damages the sinus node or affects the sinus node supply. hypertension. Hyperthyroidism. Muscular dystrophy. Hemochromatosis. Friedreiech hereditary ataxia. Congenital and rheumatic heart disease. Drug poisoning. Electrolyte balance disorders and some such as digitalis. Beta-adrenergic blockers. Calcium channel antagonists. Antiarrhythmic drugs and drugs such as lithium carbonate can exacerbate sinus node dysfunction.

Diagnosis of sick sinus node syndrome

The diagnosis of this disease should be based on arrhythmia. Symptoms are for reference only. Middle-aged and young people often use atropine, isoprenaline test, esophageal atrial pacing and other tests to confirm the diagnosis. Can basically achieve the purpose of diagnosis. If the slowest sinus rhythm is <40 / min and the longest R-R <1.6s, it can be diagnosed.

Treatment options for sick sinus node syndrome

Treatment should be directed to the cause, asymptomatic patients can be followed up regularly to closely observe the condition. Those with slow and significant heart rate or with symptoms may try atropine or Shuchuanling orally. Patients with double-knot disease, slow-onset syndrome, and patients with obvious symptoms of inadequate cerebral blood supply, such as near syncope or syncope, should be placed with an on-demand artificial cardiac pacemaker. Atrioventricular sequence on-demand pacemaker is more physiological than VVI. For patients with tachyarrhythmia, a pacemaker is installed and drugs are added to control the tachyarrhythmia. Recently, there is still a program-controlled automatic scan pacemaker for the treatment of slow-onset syndrome (see the chapter on artificial pacemakers). When bradycardia occurs, VVI is used for pacing. When tachycardia occurs, VVI is converted to VVT. The burst of rapid stimuli stops the tachycardia episode. Patients with sick sinus syndrome are prohibited from using drugs that may slow the heart rate, such as antihypertensive drugs, antiarrhythmic drugs, cardiotonic drugs, -adrenergic blockers and calcium antagonists. Cardiac cardioversion should not be performed when atrial fibrillation or atrial flutter occurs. The treatment of this disease is difficult because of the lack of effective and no side-effect drugs for slow arrhythmia, the use of drugs for the prevention and treatment of tachyarrhythmia aggravates the slowness of the heart rhythm, and the heartbeat pauses for a long time when the fast heart rate turns to a slow heart rate. Therefore, three points should be paid attention to in the treatment of this disease: Any medicine that improves the heart rhythm can only be used for emergency treatment, and it should not be used for a long time. Symptoms are used as the basis for selecting a treatment plan. If there are unexplained symptoms such as dark haze, syncope, etc., you should Install an artificial pacemaker. Pacemaker syndrome is likely to occur in elderly people who install VVI pacemaker. If the pacemaker frequency is slowed down, try to maintain the patient's own sinus rhythm and reduce its occurrence. Do not use drugs that inhibit sinoatrial nodes (verapamil, beta blockers, etc.) before installing a pacemaker.