Comprehensive Cardiomyopathy and Arrhythmias Panel

Turnaround time: 7-24 days

Preferred specimen: BD Vacutainer Whole Blood K2 EDTA Collection Tube 4mL or Oragene Dx Saliva Collection Kit

Shipping instructions: Specimens to arrive at Helix within 96 hours of collection at ambient temperature.

Hypertrophic Cardiomyopathy (HCM) is a condition in which the heart muscle becomes abnormally thick. This leads to a decrease in the heart's ability to pump blood effectively. This can cause fatigue, shortness of breath, swelling of the legs, heart rhythm abnormalities and, in severe cases, heart failure or sudden cardiac arrest.

Dilated Cardiomyopathy (DCM) is a condition in which the heart chambers become enlarged, weakening the heart muscle. LVNC is characterized by endomyocardial trabeculations which can have variable effects on heart musculature, including ventricular dilation. Individuals with DCM or LVNC may be asymptomatic, or may be symptomatic with arrhythmia, left ventricular dysfunction, thromboembolic disease, and/or life-threatening arrhythmias.

Long QT syndrome (LQTS) is an electrophysiologic disorder of the heart that is characterized by prolongation of the QT-interval and T-wave abnormalities, as measured by electrocardiogram (ECG). These may manifest as palpitations, seizures, or arrhythmogenic events such as torsade de pointes (TdP) which may result in syncope or, in rare cases, cardiac arrest or sudden death.

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an electrophysiologic disorder of the heart which predisposes those affected to develop arrhythmias. While patients with CPVT often have normal resting electrocardiograms (ECGs) and normal heart imaging, both exercise and emotional stress can risk development of arrhythmogenic events (commonly ventricular tachycardia) which may result in syncope or, in rare cases, cardiac arrest or sudden death.

Short QT syndrome (SQTS) is an electrophysiologic disorder of the heart that is characterized by an abnormally short QT-interval, as measured by electrocardiogram (ECG). This can result in abnormal heart rhythms that can cause palpitations, fainting and an increased risk of sudden cardiac death.

Brugada syndrome (BrS) is an electrophysiologic disorder of the heart that is characterized by pathognomonic electrocardiogram (ECG) findings. These findings are associated with increased risk for arrhythmogenic events which may result in syncope or, in rare cases, cardiac arrest or sudden death.

Arrhythmogenic cardiomyopathy (ACM) is characterized by fibrofatty infiltration of ventricle musculature which may present as arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC) or arrhythmogenic left ventricular cardiomyopathy/dysplasia (ALVC). These findings are associated with increased risk for ventricular dysfunction, and arrhythmogenic events which may result in syncope or, in rare cases, cardiac arrest or sudden death.

Hereditary transthyretin amyloidosis (hATTR) is a slowly progressive, adult-onset neuromuscular condition, characterized by a gradual buildup of amyloid in different organs, tissues, and nerves. This amyloid buildup may gradually cause restrictive cardiomyopathy, autonomic neuropathy, peripheral sensorimotor neuropathy, nephropathy, or in some cases effects to the central nervous system such as seizures, dementia, and psychosis.

Individuals with these conditions may be asymptomatic, or may be symptomatic with some/many of the features described above. It is important to note that in some cases these heart conditions may be a feature of a larger syndromic condition. Hereditary forms of HCM, DCM and LVNC may follow autosomal dominant, autosomal recessive, X-linked or mitochondrial inheritance patterns. Hereditary forms of LQTS, CPVT and ACM may follow autosomal dominant or autosomal recessive inheritance patterns. Hereditary forms of BrS, SQTS and ATTR have been seen to follow an autosomal dominant inheritance pattern. This panel does not assess mitochondrial inheritance.

All detected variants are evaluated according to American College of Medical Genetics and Genomics recommendations. Variants are classified based on known, predicted, or possible pathogenicity and reported with interpretive comments detailing their potential or known significance.