Hello, welcome everybody, this is doctor Bolad, board certified physician in cardiology, interventional
cardiology and internal medicine, certified by the American Board of Internal Medicine.
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I recently got a few questions from my patients about the causes of dilated enlarged heart,
so I made this video to explain the causes. When the heart dilates, it is commonly accompanied
by reduced heart function, and this is medically referred to as DILATED CARDIOMYOPATHY. Affected
patients may or may not develop overt heart failure. Dilated cardiomyopathy is responsible
for about ten thousand deaths and forty-six thousand hospitalizations each year in the
United States. The disease is considered IDIOPATHIC, meaning of unknow cause, if primary and secondary
causes of heart disease are excluded by history and physical examination and heart testing.
Affected patients can present in a number of different ways. Symptoms of heart failure
like progressive shortness of breath with exertion, impaired exercise capacity, shortness
of breath on lying flat in bed at night, and leg swelling are most common.
Dilated cardiomyopathy can be caused by a variety of disorders. These include,
Coronary artery disease. This is the most common cause of heart failure in the United
States, comprising fifty to seventy five percent of patients with HF. This usually occurs when
there is damage to the heart secondary to coronary artery blockage, which causes the
heart to enlarge. Infections. A variety of infectious organisms
can lead to myocarditis and cardiomyopathy and these include Viruses. These are the most
common cause of infectious myocarditis and dilated cardiomyopathy. Viruses known to involve
the myocardium include parvovirus B19, coxsackievirus, influenza virus, cytomegalovirus and HIV.
Infectious cardiomyopathy also occurs in Chagas disease which is a protozoan infection due
to Trypanosoma cruzi, and this is the leading cause of dilated cardiomyopathy in Central
and South America. Lyme disease is usually manifested as a conduction abnormality but
cardiac muscle dysfunction can also occur. Stress-induced cardiomyopathy is an uncommon
but increasingly reported cause of ACUTE dilated cardiomyopathy This condition is also known
as transient left ventricular apical ballooning, takotsubo cardiomyopathy, and broken heart
syndrome. This disorder is typically precipitated by intense psychologic stress and primarily
occurs in postmenopausal women. Genetic causes of dilated cardiomyopathy occurs
in individuals who develop heart dilation and failure in a familial pattern, and there
is no underlying cause for the cardiomyopathy other than the family history.
Toxic dilated cardiomyopathy can be a direct result of toxic exposure from a variety of
agents, most notably excessive alcohol intake, cocaine use, certain medications particularly
chemotherapeutic drugs used to treat malignancies and radiation therapy.
Peripartum cardiomyopathy is a rare cause of dilated cardiomyopathy of unclear etiology
that occurs in late pregnancy and the early postpartum period. The diagnosis requires
exclusion of other causes of cardiomyopathy Tachycardia-mediated cardiomyopathy is a condition
that occurs when the heart weakens and dilates secondary to fast heart rate over a prolonged
period of time. This type of cardiomyopathy occurs in patients with chronic supraventricular
tachycardias with heart rates of 130 to 200 beats/minute including atrial fibrillation,
atrioventricular nodal reentry and preexcitation syndromes
The treatment of the dilated cardiomyopathy depends on the cause of the cardiomyopathy.
As outlined above there are multiple causes for this cardiomyopathy. As an example, if
the dilated cardiomyopathy was secondary to coronary artery disease, then treating the
coronary artery blockages can improve or reverse the cardiomyopathy. If the cause was secondary
to fast heart rate over a prolonged period of time, then controlling the heart rate with
medications will reverse the condition. Other treatment modalities apply to the other causes
of cardiomyopathy. If you have any question about what I presented
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share this video with family and friends. This is Doctor Bolad, helping you with your
heart health, thanks for watching, and talk to you soon.