About Cardiac Channelopathies and Cardiomyopathies

What are cardiac channelopathies?
 Cardiac channelopathies occur when the proteins forming ion channels in the heart do not function properly. In some patients, cardiac channelopathies cause noticeable symptoms from an early age, but in others they can go undetected for years until unexpectedly causing symptoms.

Symptoms from cardiac channelopathies may occur spontaneously in the hereditary disorders or be caused by reactions to certain drugs. Regardless of the trigger, the heart can beat irregularly causing symptoms such as fainting or seizures and lead to the diagnosis or tentative diagnosis of potentially dangerous conditions, such as:

• Long QT Syndrome (LQTS) - Executive Summary
• Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT) - Executive Summary
• Brugada Syndrome  (BrS) - Executive Summary

What are cardiomyopathies?
Cardiomyopathies are a group of inherited heart diseases that cause the heart muscle to become abnormally enlarged, thickened, and /or stiffened diminishing the heart’s ability to function and creating the potential for arrhythmias. In some patients, cardiomyopathies cause noticeable symptoms from an early age, but in others they can go undetected for years until unexpectedly causing symptoms. Cardiomyopathies can cause the heart to beat irregularly causing symptoms such as fainting or seizures and lead to the diagnosis of potentially dangerous conditions, such as:

• Hypertrophic Cardiomyopathy (HCM) - Executive Summary
• Arrhythmogenic Right Ventricular Cardiomyopathy( ARVC) - Executive Summary

Left untreated or undiagnosed all these syndromes could cause sudden cardiac death.

Practice Guidelines for Genetic Testing
The Heart Failure Society of America’s recent practice guideline titled Genetic Evaluation of Cardiomyopathy joins the ACC/AHA/ESC guidelines for management of patients with ventricular arrhythmias and prevention of sudden cardiac death in recommending genetic testing for numerous congenital cardiac diseases including those that can identified by the FAMILION tests.

• ACC/AHA/ESC 2006 Guidelines for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death—Executive Summary: A Report of the American College of Cardiology/American Heart Association Task Force and the European Society of Cardiology Committee for Practice Guidelines
• Genetic Evaluation of Cardiomyopathy: A Heart Failure Society of America Practice Guideline

Cost Effectiveness of FAMILION Testing
The FAMILION LQTS genetic test has been determined to be cost effective. In Heart Rhythm 2005;2:1294 –1300, Phillips et al. found:

• “We found that genetic testing (for LQTS) is more cost effective than not testing at a cost of per year of life saved of $2,500.”
• “The cost per year of life saved is well below the standard threshold of $50,000 per life-year saved, which often is used to define a cost-effective intervention.”