Q. My friend's son has something called ARVD. What is it?
A. Arrhythmogenic right ventricular dysplasia (ARVD) or cardiomyopathy is an inherited heart disorder typically affecting young males, just like your friend's son. It is not common overall, but can be serious when it does occur by predisposing those affected to extra heartbeats (thus arrhythmogenic, meaning "leads to arrhythmia"), because the pumping chamber on the right side of the heart (right ventricle) is infiltrated by fatty scar tissue (dysplasia or cardiomyopathy). If the extra heartbeats are sustained and occur in rapid sequence, the resulting arrhythmia may lead to fainting and even sudden death.
Exercise in patients with ARVD is a particular concern, as it may precipitate the arrhythmia. About half the cases have been shown to be attributable to a specific defect in the gene sequence we inherit from our parents. Perhaps because of patterns of inheritance, the disease is found most frequently in Italy, where it is a significant cause of sudden death especially in young people.
ARVD should be considered especially in a young male with fainting spells or arrhythmia that is precipitated by exertion. The diagnosis may be suggested by abnormalities on the electrocardiogram, but usually is confirmed by obtaining a biopsy specimen from the wall of the right ventricle that shows fatty infiltration and scar tissue, or with the use of magnetic resonance imaging (MRI) that can show the thinned ventricular wall.
Treatment is with medicine to reduce the risk of arrhythmia; localized burning of the scar tissue that causes the arrhythmia (ablation therapy); and most important, use of a special pacemaker (called an ICD, for internal cardioverter defibrillator) that can recognize serious arrhythmias and shock the heart back to regular rhythm. I trust that your son's friend is being followed by a cardiologist who is familiar with this somewhat unusual disease.
ADVERTISEMENT
Q. I have high blood pressure (hypertension). What causes high blood pressure? Is it related to my sleep apnea?
A. Most cases of high blood pressure are called "essential," which means we don't know the precise cause. In a small percentage of people, hypertension is caused by a potentially correctable condition such as a benign tumor or narrowing of a blood vessel going to the body (aorta) or kidney (renal artery). Obstructive sleep apnea (OSA) is a breathing disorder that can be associated with snoring, nocturnal sleep disturbance and sleepiness during the day. It too may lead to hypertension.
Treatment for almost all cases of high blood pressure includes one or more oral medications, and many patients need to take multiple medications to adequately control their hypertension and limit medication side effects. Treatment with a breathing mask at night seems to help control hypertension in those patients with OSA and high blood pressure, in addition to improving their breathing and quality of life. So yes, your high blood pressure may well be related to your sleep apnea, and treatment may help both.
Wynne is vice president for health affairs at UND, dean of the School of Medicine and Health Sciences, and a professor of medicine. He is a cardiologist by training.
Submit a question to Health Matters at healthmatters@med.und.edu or Health Matters, 501 North Columbia Road, Stop 9037, Grand Forks, ND 58202-9037. Remember, no personal details, please.
The content of this column is for informational purposes only and does not substitute for professional medical advice or care. The information provided herein should not be used for diagnosing or treating a health problem or disease. If you have or suspect you may have a health problem, you should consult your health care provider. Never disregard professional medical advice or delay in seeking it because of something you have read in this column.
