Hypertrophic cardiomyopathy

Revision as of 16:04, 15 January 2016 by Bassomar (talk | contribs) (Diagnosis)

Background

  • Genetically-linked (AD) hypertrophy of cardiac muscle - can but does not always cause outflow obstruction
  • "HOCM"
  • Abnormal LV diastolic function due to decr compliance


Diagnosis

  • Sx: Syncope or sudden death most common
    • Also exertional dyspnea, chest pain, syncope, dizzyness, palpitations, or CHF
  • Systolic murmur that increases w/ maneuvers that decrease preload (e.g. valsalva, transitioning from squatting to standing, etc.).
  • EKG
    • Nonspecific/normal.
    • Or, high voltage/LVH, deep narrow Q waves in 1, avL, V5, V6 = "daggers of death"

Work-Up

  1. EKG
  2. CXR
  3. ECHO

Differential Diagnosis

Cardiomyopathy

Chest pain

Critical

Emergent

Nonemergent

Treatment

Definitive = Myomectomy

Decompensated

  • If decompensated presents as hypotensive CHF
    • Preserve preload
      • Careful hydration
      • Avoid high airway pressure if intubate
    • Limit tachycardia
      • Beta blockers
    • Avoid vasodilators (no nitrates)
    • Maintain sinus rythm (i.e. cardiovert A. fib)
    • Increase afterload (hypotensive only)
      • Phenylephrine

Pharmacologic Management

  • Per Amer Coll of Cardiology 2011 recommendations[1]
  • Class I
    • BBs for angina or dyspnea in adults in HCM regardless of obstructive physiology - use with caution in sinus brady or conduction abnormality
    • Titrate BB dose to symptoms, may increase BB dose to resting HR to 60 bpm
    • PO verapamil titrated up to 480 mg/d if pt unresponsive or cannot tolerate BBs - caution in advanced HF, hypotension, sinus brady, high LVOT gradients
    • IV phenylephrine for acute hypotension unresponsive to fluids
  • Class IIa
    • Reasonable to add disopyramide with BB or verapamil if unresponsive to BB or CCB alone in obstructive HCM
    • Reasonable to add oral diuretics in nonobstructive HCM when symptoms persist despite BB or CCB
  • Class III (harm)
    • Avoid nifedipine and other dihydropyridine CCB
    • Avoid digitalis
    • Avoid disopyramide alone w/o BB or CCB
    • Avoid positive inotropic vasopressors (dopamine, dobutamine, norepi, epi)

See Also

Source

  • Tintinalli
  • Adapted from ....Rosen, Mattu (lecture)
  • Houston BA, Stevens GR. Hypertrophic Cardiomyopathy: A Review. Clinical Medicine Insights Cardiology. 2014;8(Suppl 1):53-65. doi:10.4137/CMC.S15717.