Young people who suffer from heart failure or cardiac events usually have a genetic cause, as highlighted by our scientific advisor, Dr. William McKenna, in a webinar organized by the Brazilian Society of Cardiology (SBC) and the Group of Family Heart Disease and Cardiovascular Genetics of the Institute for Biomedical Research of A Coruña (INIBIC, University of A Coruña), with the support of Health in Code.
Dr. McKenna specified that genetic variants that cause dilated (DCM) or arrhythmogenic cardiomyopathy (ACM) may result in two different clinical presentations. First, they may impair the pumping action of the heart’s muscle cells, causing reduced exercise capacity and overt heart failure. Further, they can also affect the electrical system of the heart, which could predispose to excessively slow or fast (or simply chaotic) electrical activation of the heart, with the consequent appearance of cardiac arrhythmias.
“Arrhythmogenic cardiomyopathy is a genetic heart muscle disorder that can cause sudden death and/or heart failure at an early age”, said our scientific advisor, Dr. William McKenna. Similarly, he highlighted that genetic variants have been identified in more than 15 genes associated with the development of arrhythmogenic cardiomyopathy and that these variants are easily detected by DNA sequencing.
ACCURATE CLINICAL DIAGNOSIS BEFORE GENETIC TESTING
When a heart disease is discovered in an individual or family, it is important to make a concise clinical diagnosis before genetic testing. If the diagnosis were erroneous, not only would the interpretation of the genes sequenced during the analysis be complicated, it would also be difficult to assess the risk the affected individuals would have.
At times, individuals with mildly impaired cardiac function and ACM are misdiagnosed with DCM. The latter causes premature heart failure, although it can also lead to sudden death, as Dr. McKenna commented. He reaffirmed, “It is important to differentiate between DCM and ACM in order to accurately identify young individuals who appear healthy but may be at risk of cardiac arrest or sudden death.”
Dr. McKenna placed great emphasis on testing for ruling out arrhythmogenic cardiomyopathy when dealing with the clinical diagnosis of dilated cardiomyopathy or myocarditis. He also underlined that family and genetic testing provides diagnostic and actionable results.
On the other hand, Dr. Arsonval Lamounier, a member of our scientific committee, presented the aspects to be taken into account by cardiologists who work with hereditary heart diseases, especially non-cardiac signs in patients and their relatives. “Cardiologists should always consider the possibility of syndromic presentations in patients with DCM or ACM. Non-cardiac signs must always be taken into account in clinical practice: neuromuscular, immunological, dermatological, and endocrine-metabolic characteristics, along with other, such as neurological, ophthalmic, and renal abnormalities”, the doctor pointed out.
“Genetic testing can be a powerful tool to establish the diagnosis and syndromic etiology. Diagnosing a syndrome has implications for the management, treatment, and counseling of these patients and their families”, concluded Dr. Lamounier.