Hypertrophic cardiomyopathy is a
heart condition for which there is
presently no cure. The severity of symptoms varies greatly among individuals, but in some cases the affliction can
lead to death.
Screening high-risk patients is the best
way to avert potential fatalities, says Dr.
Michael S. Lee, the Associate Director of
Interventional Cardiology Research and
Assistant Clinical Professor of Medicine at
UCLA Medical Center. “Hypertrophic cardiomyopathy is a complex disease that
may have catastrophic consequences.
Patients may have debilitating symptoms,
which severely affect their quality of life,”
says Lee. “Someone, especially young athletes, who may be viewed as a picture of
health may suddenly die without any warning.”
Smart Business spoke with Lee about
hypertrophic cardiomyopathy, how it is
diagnosed and what treatment options are
available.
What is hypertrophic cardiomyopathy?
Hypertrophic cardiomyopathy is a condition in which there is excessive thickening
of the heart muscle or hypertrophy. The
heart muscle may thicken in normal individuals due to hypertension or prolonged
athletic training. However, in hypertrophic
cardiomyopathy, muscle thickening occurs
without an obvious cause. Microscopic
examination of the heart muscle shows
myocardial disarray or irregular, disorganized alignment of muscle cells.
How common is this condition?
Hypertrophic cardiomyopathy is a relatively common genetic cardiac disorder,
which affects about one in 500 adults in the
general population.
What causes hypertrophic cardiomyopathy?
The cause of hypertrophic cardiomyopathy is not fully known. Although the majority of cases are inherited, others have
either no evidence of inheritance or there is insufficient information about the individual’s family to assess inheritance. More
than 400 genetic mutations have been identified in patients with hypertrophic cardiomyopathy, most of which are genes that
encode contractile proteins of the cardiac
sarcomere. The condition usually passes
from one generation to the next in affected
families, and generations are not skipped.
What are some common symptoms?
Hypertrophy more commonly develops
in association with growth and is usually
apparent by the late teens or early twenties. While some patients are asymptomatic, others may experience chest pain,
shortness of breath, fatigue, palpitations,
light-headedness, dizziness, and blackouts.
Other complications include arrhythmias
(like atrial fibrillation and ventricular
tachycardia), and endocarditis (or infection of the heart).
However, the most devastating manifestation is sudden death, which may occur
with little or no warning.
How is hypertrophic cardiomyopathy diagnosed?
Hypertrophic cardiomyopathy may be
suspected because of symptoms, a murmur, or an abnormal electrocardiogram,
but the diagnosis is made by an ultrasound
scan of the heart called an echocardio-gram. Family screening of first-degree relatives will also identify children and adolescents with the condition.
What are the treatment options in patients
with hypertrophic cardiomyopathy?
Although there is no cure, treatment
options are available to improve symptoms
and prevent complications. Medications
like beta-blockers and calcium antagonists
can reduce symptoms. Anti-arrhythmic
drugs like amiodarone can be used to
reduce the risk of sudden death. Patients
should also take antibiotics before invasive
procedures like teeth cleaning to prevent
an infection of the heart valves called endocarditis.
If severe symptoms persist despite drug
therapy, surgical myectomy (removal of
muscle) can successfully relieve symptoms
in patients whose left ventricular outflow
tract is narrowed and causes obstruction
of blood flow. Another option for patients
with severe symptoms is non-surgical
myectomy, in which a small amount of
alcohol solution is injected into a minor
branch of the coronary artery that supplies
the upper septum, thus destroying this part
of the heart muscle.
The best way to prevent sudden death is
to screen and identify high-risk patients for
sudden death and implant a defibrillator, a
small device under the skin in the chest,
which records and delivers an electrical
shock when normal electrical action is
absent. Patients may be advised not to participate in competitive sports or other
strenuous physical effort.
DR. MICHAEL S. LEE is the Associate Director of
Interventional Cardiology Research and Assistant Clinical
Professor of Medicine at UCLA Medical Center. Reach him at
(310) 825-8811.