Hypertrophic Obstructive Cardiomyopathy (HOCM)

 

 

Considerations

 

  • Dynamic LVOT obstruction (20-30% of patients) & need to avoid precipitants

  • Perioperative hemodynamic complications:

    • Arrhythmia

    • Ischemia & diastolic dysfunction

    • Secondary hypertrophy

    • MR

    • End stage: dilated cardiomyopathy

  • Medication management: 

    • Beta blockers & calcium channel blockers

    • Antiarrhythmics

    • Anticoagulants

    • Diuretics

  • Pacemaker/ AICD

 

 

Goals

 

  • Preload: maintain preload

  • Rate & rhythm: slow-normal rate; maintain sinus rhythm

  • Contractility: ↓ contractility

  • Afterload: maintain or ↑ afterload

 

 

Pregnancy

 

  • Usually tolerated well 

  • Continue beta blockers in pregnancy 

  • Goals:

    • Maintenance of intravascular volume & venous return

    • Avoidance of aortocaval compression

    • Maintenance of adequate SVR

    • Maintenance of a slow heart rate in sinus rhythm

    • Aggressive treatment of acute atrial fibrillation & other tachyarrhythmias

    • Prevention of increases in myocardial contractility

  • Anesthetic technique:

  • Likely need extra monitoring: arterial line, 5 lead ECG, possible CVC, tertiary/cardiac centre 

  • Spinal relatively contraindicated because of the rapid onset of a sympathectomy

  • Epidural for elective cesarean section well tolerated 

  • GA also well tolerated 

  • They tolerate 2nd stage of labor well as ↑SVR helps HOCM, could consider assisted 2nd stage if needed 

  • Postpartum hemorrhage: oxytocin OK if given slowly; ergot a great agent

 

 

Atrial Fibrillation in HOCM Patient

 

  • Acute in OR, best measure is cardioversion 

  • Beta blockers also very good choice (e.g. esmolol infusion)