A recent Canadian study found that children with HCM who carry a single mutation in the MYH7 gene or who have multiple HCM-causative genetic mutations are at increased risk of major adverse cardiac events when compared to children who carry a single mutation in another gene.
Of the 98 gene positive children in this study, those with a MYH7 mutation or those with multiple mutations were more likely to need a myectomy or an ICD or to experience a sudden cardiac arrest or a heart transplant when compared to children with other HCM causative mutations.
The article also suggests that current screening protocols which recommend clinical and genetic screening for HCM beginning at age 12 may be insufficient.
Editor’s Note: This post originally appeared on the blog of Dr. Howard J. Luks. Dr. Luks wrote this blog entry in collaboration with HCM expert Dr. Srihari S. Naidu of New York’s Westchester Medical Center. You can find the original post here. You can find both Dr. Luks and Dr. Naidu on Twitter @hjluks and @SrihariNaiduMD.
Sudden cardiac death in young athletes continues with alarming frequency. The most common cause of sudden death in the young athlete is hypertrophic cardiomyopathy or HCM. Simply put, HCM means the heart muscle is bigger. Many of us believe that bigger muscle means stronger muscle. That is not always the case with the heart. The heart is a mechanical pump with a complex arrangement of chambers which store the blood. How that pump works is controlled by a very complex electrical system. Hypertrophic cardiomyopathy can interfere with one or both of these critical functions of the heart and lead to sudden cardiac death.
Continue reading “Sudden Cardiac Death in Young Athletes”
According to researchers at the University of Michigan, family members of HCM patients who have tested negative for genes associated with HCM and without a family history of HCM will usually be found to be free of HCM during routine family screening. And, in accordance a recent Australian study, relatives of these patients may be able to benefit from less rigorous screening protocols.
Patients with a known sarcomere mutation appear to have a different clinical profile, according to the researchers: they have more hypertrophy; they are younger when diagnosed; they have a higher risk for adverse events; and they are more likely to have a family history for the condition.
In contrast, when the initial diagnosis is made in a patient who is 50 or older with no known genetic mutations, a negative family history, and sigmoidal septal pattern hypertrophy, reduced family screenings may be appropriate and less burdensome. In addition, hypertension, large family size with no other affected family members, less severe hypertrophy, and lack of life-threatening complications related to HCM may provide additional comfort to families of newly diagnosed HCM patients.
The reduced protocol would consist of a single screening of adult family members, with the caveat that if and when any additional family additional member is found to have HCM, a more traditional screening protocol be instituted.
(Note that standard screening guidelines recommend screening of all first-degree family members of patients beginning with adolescence, repeated annually through the end of adolescent growth, and repeated every 3 – 5 years for life.)
Lisa Yu, founder of Children’s Cardiomyopathy Foundation, posted this article today on Huffington Post. This piece summarizes the efforts currently being made to screen Olympic athletes and elaborates on how better screening and response protocols might help to avoid tragedies.
A recent study followed 14 patients carrying one of two known genes associated with HCM (MYBPC3 and MYH7) over a 10+ year period . At the time of gene identification, none of the patients shown clinical evidence of hypertrophy. Over the time span of the study, 3 patients, who were then adults, had developed signs of HCM. Hence, the study suggests that periodic screenings are necessary for gene positive individuals throughout adulthood.
According to Cardiomyopathy U.K., the researchers undertook this project due to the lack of information and guidelines available to patients who are gene positive but have no outward signs of the disease.