Cardiomyopathy and Myocardial Disease

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Cardiomyopathy and Myocardial Disease

• Jill R. Tichy M.D.
• PGY II

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Three Broad Categories of Cardiomyopathy

• Dilated
• Hypertrophic
• Restrictive

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Definition and classification of cardiomyopathy-
American Heart Association (AHA) in 2006

• Mechanical and/or electrical dysfunction that
  usually exhibit inappropriate ventricular
  hypertrophy or dilitation
• Due to a variety of causes frequently genetic
• Either confined to the heart or are a part of
  generalized systemic disorders

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Cardiomyopathy Semantics courtesy of AHA and ESC

• Originally defined as disorders that are
  idiopathic/genetic
• Valvular, Ischemic or Hypertensive cardiomyopathy
  was deemed incongruent with the above definitions
  in 2006-2007

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Dilated Cardiomyopathy (DCM) by definition

• Chamber enlargement and impaired systolic
  function of one or both ventricles
• Normal LV wall thickness
• Unrelated to hypertension or ischemic heart
  disease

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DCM related facts

• Estimated prevalence of 12500
• Third most common cause of heart failure
• Most frequent cause of heart transplantation

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A word on myocarditis

• Inflammation of the myocardium
• Frequently a result from viral infections-direct
  invasion into the myocytes
• During acute phase of illness cardiac enzyme
  leakage is found
• Endomyocardial biopsy of the right ventricle
  remains the gold standard for diagnosis

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Myocarditis

• Clinical course variable
• In some patients depressed ventricular function
  may develop in the absence of symptoms
• Manifests months to years later as dilated
  cardiomyopathy

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Causes of DCM

• Idiopathic
• Toxin induced EtOH, Anthracycline, Cobalt,
  Cocaine, Crystal Meth
• Radiation
• Infectious Viral (coxsackievirus, adenovirus,
  parvovirus, human immunodeficiency virus HIV) ,
  Parasites (Chagas Disease)
• High Ouput States Anemia, Peripartum, Thiamine
  deficiency, Thyrotoxicosis
• Sarcoidosis
• Amyloidosis
• Hemochromatosis
• Genetic

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Idiopathic DCM-diagnosis of exclusion

• Responsible for half of DCM diagnoses
• Exclusion of gt 50 obstruction of one or more
  coronary arteries
• Exclusion of active myocarditis
• Exclusion of a primary or secondary form of heart
  muscle disease

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Genetic causes of DCM

• About 20-30 of dilated cardiomyopathy cases have
  been reported as familial
• Autosomal Dominant trait with variable penetrance

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Dilated (Congestive) DCM Symptoms

• Dyspnea on exertion
• Orthopnea, paroxysmal nocturnal dyspnea
• Fatigue
• Lower Extremity Edema, increasing abdominal girth

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Sequelae

• Ventricular and supraventricular arrhythmias
• Conduction system abnormalities
• Thromboembolism
• Sudden or heart failurerelated death.

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Medical Management of DCM

• Similar to congestive heart failure
• Clinical outcome has improved with ACEI and more
  recently B-Blocker therapy
• Supportive avoidance of exercise, EKG monitoring
  for arrhythmias, contraception?

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Prognosis of advanced heart failure in DCM

• 5-year mortality is in excess of 50
• Hyponatremia at the time of presentation was
  found to be a marker of increased stimulation of
  the renin-angiotensin axis and of worsening of
  the disease course and prognosis.

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References

• Andreoli, et al. Cecil Essentials of Medicine.
  6th Edition.
• Griffin, B. Manual of Cardiovascular Medicine.
  2004
• Cooper,L. Definition and classification of the
  cardiomyopathies, a literature review. Feb 2008
• Blackstock, U. Cardiomyopathy, Dilated-a
  literature review. Dec 2007