What causes sick sinus syndrome?
Sick sinus syndrome may be brought on by the use of certain drugs, but is most common in elderly patients. Cardiac amyloidosis, a condition in which amyloid, a kind of protein, builds up in heart tissue, may affect the sinus node. Other conditions, such as sarcoidosis (round bumps in the tissue surrounding the heart and other organs), Chagas' disease
(resulting from the bite of a bloodsucking insect) or certain cardiac myopathies can cause fiber-like tissue to grow around the normal sinus node, causing the node to malfunction.
Sick sinus syndrome is a relatively uncommon syndrome. It can result in many abnormal heart rhthyms (arrhythmias), including sinus arrest, sinus node exit block, sinus bradycardia, and other other types of bradycardia (slow heart rate). Sick sinus syndrome may also be associated with tachycardias (fast heart rate) such as PSVT and atrial fibrillation. Tachycardias that occur with sick sinus syndrome are characterized by a long pause after the tachycardia.
Abnormal rhythms are often caused or worsened by medications such as digitalis, calcium channel blockers, beta-blockers, sympatholytic medications, and anti-arrhythmics. Disorders that cause scarring, degeneration, or damage to the conduction system can cause sick sinus syndrome, including sarcoidosis, 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 system. Cardiac surgery, especially to the atria, is a common cause of sick sinus syndrome in children.
Sick sinus syndrome may also be associated with tachycardias (fast heart rate) such as PSVT and atrial fibrillation. Tachycardias that occur with sick sinus syndrome are characterized by a long pause after the tachycardia. Abnormal rhythms are often caused or worsened by medications such as digitalis, calcium channel blockers, beta-blockers, sympatholytic medications, and anti-arrhythmics. Disorders that cause scarring, degeneration, or damage to the conduction system can cause sick sinus syndrome, including sarcoidosis, 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 conduction system. Cardiac surgery, especially to the atria, 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. |
