Sick sinus syndrome most often occurs in people older than 50. It is often due to scar-like damage to electrical pathways in the heart muscle tissue. In children, heart surgery on the upper chambers is a common cause of sick sinus syndrome.Coronary artery disease, high blood pressure, and aortic and mitral valve diseases may occur with sick sinus syndrome. Coronary Artery Disease is damage or disease in the heart's major blood vessels. Mitral Valve Disease refers to conditions of the mitral valve. Located between the left chambers of your heart, this valve works to keep blood flowing properly.

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