Definition:

Dilated cardiomyopathy is the most common diagnosis in patients that receive US Medicare financial supplementation.  It is a condition where the normal muscular function of the heart (myocardium) is altered by various etiologies, and there is some physiologic compensation for this malfunction.  The condition in essence causes a decrease in the contractile force of the heart ventricle(s) without any pressure/volume overload.  The loss of this cardiac muscle function can result in congestive heart failure.  It can be caused by: prolonged alcohol use, doxorubicin use, exposure to mercury/lead/catecholamines, thyrotoxicosis, metabolic disorders, genetic abnormalities, and prolonged tachycardia.  

Symptoms:

• Orthopnea (shortness of breath when lying flat)
• Paroxysmal nocturnal dyspnea (waking up at night with shortness of breath)
• Dyspnea on exertion
• Tachycardia (elevated heart rate)
• Neck vein distension
• Ascites (enlarged abdominal girth secondary to increased fluid in the abdomen)
• Edema (swelling caused by fluid) in the legs

Diagnosis:

• Physical exam
  • Pulmonary rales
  • Cardiac enlargement
  • 3rd and 4th heart sounds by stethoscope
  • Liver enlargement
• EKG - shows left ventricle hypertrophy
• Chest X-Ray - shows enlarged heart that is >50% size of chest wall
• Gated blood pool scanning - to evaluate ejection fraction of the heart chambers
• Echocardiography - evaluates the contractile force of heart chambers
• Cardiac Catheterization - to exclude ischemic heart disease

Treatment:

• Remove offending agent (doxorubicin, toxin, etc)
• Supportive therapy
  • Salt restriction in diet
  • Cardiac glycosides
  • Diuretics
  • Vasodilators
  • ACE inhibitors
  • Beta-blockers
• Heart transplantation - if prognosis poor