Sick sinus syndrome: Facts, Discussion Forum, and Encyclopedia Article

All Topics

Sick sinus syndrome

	Email		Print
	Bookmark		Link

	Sick sinus syndrome
	Home Discussion
	Topics Sick sinus syndrome Topic Home Sick sinus syndrome, also called Sinus node dysfunction, is a group of abnormal heart rhythms presumably caused by a malfunction of the sinus node, the heart's "natural" pacemaker. Bradycardia-tachycardia syndrome is a variant of sick sinus syndrome where atrial flutter and fibrillation alternate with prolonged periods of asystoleAsystole In medicine, asystole is a state of no cardiac electrical activity, hence no contractions of the myocardium and no cardiac o... . Causes Sick sinus syndrome is a relatively uncommon syndrome. It can result in many abnormal heart rhythms (arrhythmias), including sinus arrest, sinus node exit block, sinus bradycardiaSinus bradycardia Sinus bradycardia is a heart rhythm that originates from the sinus node and has a rate of under 60bpm. ... , and other types of bradycardiaBradycardia Bradycardia , as applied in adult medicine, is defined as a resting heart rate of under 60 beats per minute, though it is se... (slow heart rate). Sick sinus syndrome may also be associated with tachycardiaTachycardia Tachycardia is an abnormally rapid beating of the heart, defined as a resting heart rate of 100 or more beats per minute in ... s (fast heart rate) such as paroxysmal supraventricular tachycardia (PSVT) and atrial fibrillation. Tachycardias that occur with sick sinus syndrome are characterized by a long pause after the tachycardiaTachycardia Tachycardia is an abnormally rapid beating of the heart, defined as a resting heart rate of 100 or more beats per minute in ... . Abnormal rhythms are often caused or worsened by medications such as digitalisDigitalis *Digitalis* is a genus of about 20 species of herbaceous biennials, perennials and shrubs that was traditionally placed in... , calcium channel blockerCalcium channel blocker Calcium channel blockers are a class of drugs with effects on many excitable cells of the body, like the muscle of the heart... s, beta-blockers, sympatholytic medications, and anti-arrhythmics. Disorders that cause scarring, degeneration, or damage to the conduction system can cause sick sinus syndrome, including sarcoidosisSarcoidosis Sarcoidosis is an immune system disorder characterised by non-necrotising granulomas.... , amyloidosis, Chagas' disease, and cardiomyopathies. Sick sinus syndrome is more common in elderly adults, where the cause is often a non-specific, scar-like degeneration of the cardiac conduction systemElectrical conduction system of the heart The normal electrical conduction in the heart allows the impulse that is generated by the sinoatrial node of the heart to be propa... . Cardiac surgery, especially to the atriaAtria Atria may refer to:*Atria is an alternative spelling for the Etruscan city that is now Adria in the Veneto region of ... , is a common cause of sick sinus syndrome in children. Coronary artery disease, high blood pressure, and aortic and mitral valve diseases may be associated with sick sinus syndrome, although this association may only be incidental. Symptoms Even though many types of sick sinus syndrome produce no symptoms, patients may present with: Stokes-Adams attackStokes-Adams attack The term Stokes-Adams Attack refers to a sudden, transient episode of syncope, occasionally featuring seizures.... s - fainting due to asystoleAsystole In medicine, asystole is a state of no cardiac electrical activity, hence no contractions of the myocardium and no cardiac o... or ventricular fibrillationVentricular fibrillation Ventricular fibrillation is a cardiac condition that consists of a lack of coordination of the contraction of the muscle tis... Dizziness or light-headedness Palpitations Chest pain or angina Shortness of breath Fatigue Headache Nausea Diagnosis Ambulatory monitoring of the electrocardiogramElectrocardiogram An electrocardiogram is a graphic produced by an electrocardiograph, which records the electrical voltage in the heart... (ECG) may be necessary because arrhythmias are transient. The ECG may show any of the following Inappropriate sinus bradycardia Sinus arrest Sinoatrial block Atrial fibrillation with slow ventricular response A prolonged asystolic period after a period of tachycardias Atrial flutter Ectopic atrial tachycardia Sinus node reentrant tachycardia Electrophysiologic tests are no longer used for diagnostic purposes because of their low specificity and sensitivity. Cardioinhibitory and vasodepressor forms of sick sinus syndrome may be revealed by tilt table testing. Treatment Bradyarrhythmias are well controlled with pacemakers, while tachyarrhythmias respond well to medical therapy. However, because both bradyarrhythmias and tachyarrhythmias may be present, drugs to control tachyarrhythmia may exacerbate bradyarrhythmia. Therefore, a pacemaker is implanted before drug therapy is begun for the tachyarrhythmia. External links