Hypertrophic cardiomyopathy: Difference between revisions

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==Background==
==Background==
*Genetically-linked (AD) hypertrophy of cardiac muscle - can but does not always cause outflow obstruction
*Genetically-linked (AD) hypertrophy of cardiac muscle - can but does not always cause outflow obstruction
*"HOCM"
*Abnormal LV diastolic function due to decreased compliance
*Abnormal LV diastolic function due to decreased compliance
*Historically, obstructive forms known as:
*Historically, obstructive forms known as:
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**Asymmetric septal hypertrophy (ASH)
**Asymmetric septal hypertrophy (ASH)
*Yamaguchi syndrome, an atypical HCOM, in which only 1% are non-Japanese
*Yamaguchi syndrome, an atypical HCOM, in which only 1% are non-Japanese
<gallery>
 
File:Hypertrophic_cardiomyopathy.png|Schematic of hypertrophic cardiomyopathy
[[File:Hypertrophic_cardiomyopathy.png|thumb|HOCM]]
</gallery>
 
==Clinical Features==
 
 
==Differential Diagnosis==
{{Cardiomyopathy DDX}}
 
{{Chest Pain DDX}}


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


==Work-Up==
===Work-Up===
#[[EKG]]
*[[EKG]]
##May show signs of:
**May show signs of:
###LVH
***LVH
###"Needle-like" Q waves
***"Needle-like" Q waves
#CXR
*CXR
#ECHO
*ECHO


==Differential Diagnosis==
==Management==
{{Cardiomyopathy DDX}}
*Definitive treatment is myomectomy
 
{{Chest Pain DDX}}
 
==Treatment==
Definitive = Myomectomy


===Decompensated===
===Decompensated===
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**Avoid disopyramide alone w/o BB or CCB
**Avoid disopyramide alone w/o BB or CCB
**'''Avoid positive inotropic vasopressors''' (dopamine, dobutamine, norepi, epi)
**'''Avoid positive inotropic vasopressors''' (dopamine, dobutamine, norepi, epi)
==Disposition==
*Admit


==See Also==
==See Also==
*[[Cardiomyopathy]]
*[[Cardiomyopathy]]


==Source==
==References==
*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.
<references/>
<references/>


[[Category:Cards]]
[[Category:Cards]]

Revision as of 00:23, 22 February 2016

Background

  • Genetically-linked (AD) hypertrophy of cardiac muscle - can but does not always cause outflow obstruction
  • Abnormal LV diastolic function due to decreased compliance
  • Historically, obstructive forms known as:
    • Idiopathic hypertrophic subaortic stenosis (IHSS)
    • Asymmetric septal hypertrophy (ASH)
  • Yamaguchi syndrome, an atypical HCOM, in which only 1% are non-Japanese
HOCM

Clinical Features

Differential Diagnosis

Cardiomyopathy

Chest pain

Critical

Emergent

Nonemergent

Diagnosis

  • Sx: Syncope or sudden death most common
    • Also exertional dyspnea, chest pain, syncope, dizziness, 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

  • EKG
    • May show signs of:
      • LVH
      • "Needle-like" Q waves
  • CXR
  • ECHO

Management

  • Definitive treatment is myomectomy

Decompensated

  • Consider primary insult, which usually is preload issue (fluid depletion, bleed, etc.)
  • 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, max dose range depending on source
        • Start at 100 mcg/min (~1.5 mcg/kg/min for average adult)
        • Range usually 0.5 - 6.0 mcg/kg/min, with efficacy minimal beyond 6 mcg/kg/min)[1]
        • Max phenylephrine infusion before other pressors
        • Fix acid-base disorder as acidosis may prevent pressor efficacy
        • Consider maxing vasopressin next
          • Pressor effects more preserved in hypoxia and acidosis[2]
          • Preferred over pressors with beta agonism
      • Push dose pressor while waiting for IV drip:
        • Place 1mL of 10mg/mL phenylephrine in 100mL NS
        • Final concentration 100mcg/mL
        • Use 1-2mL q2-5min (100-200mcg) in 10mL syringe
        • Onset 1min; duration 20min

Pharmacologic Management

  • Per Amer Coll of Cardiology 2011 recommendations[3]
  • 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)

Disposition

  • Admit

See Also

References

  1. ↑ Global RPH in reference to Micromedex. 12/2014. http://www.globalrph.com/phenylephrine_dilution.htm
  2. ↑ Overgaard CB and Dzavik V. Contemporary Reviews in Cardiovascular Medicine: Inotropes and Vasopressors - Review of Physiology and Clinical Use in Cardiovascular Disease. Circulation. 2008; 118: 1047-1056.
  3. ↑ American College of Cardiology. 2011. http://content.onlinejacc.org/article.aspx?articleid=1147838
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