Hypertrophic cardiomyopathy with acute decompensation
Encounter flow
12/12 authoredCanonical 12-phase frame with authored status for this dossier.
Frame
Acute decompensation in HCM = dynamic LVOT obstruction (SAM-driven) + diastolic dysfunction + often AFib — preload/afterload-dependent. Treatment paradox vs ADHF: give fluids, give phenylephrine, slow HR with esmolol, AVOID inotropes / vasodilators / aggressive diuresis
HCM-specific physiology framed before any drug ordered
Patient inputs (15)
Age input for ESC HCM-RISK-SCD; older patients more likely to have AF and require AC; mavacamten and disopyramide tolerability depends on age and frailty
HypoK in hypertrophied stiff LV worsens VT/VF risk; also affects disopyramide proarrhythmia; replete K to ≥4.0
ESC HCM-RISK-SCD component + ACC/AHA 2024 SCD risk stratification; cascade screening referral
Detect inadvertent vasodilators (ACEi, ARB, nitrates), inotropes, or aggressive diuretics that may have precipitated obstruction crisis; need to stop or switch
Bedside or formal TTE — resting + provocable LVOT gradient, SAM, septal thickness, LVEF, mitral regurgitation severity — drives ALL drug decisions
Asymmetric septal hypertrophy ≥15 mm (≥13 mm with FH or genetic confirmation) — diagnostic anchor; ≥30 mm = high-SCD-risk band per ACC/AHA 2024 HCM
LVH voltage criteria, lateral T-wave inversion, abnormal Q-waves; new AFib detection drives immediate AC + rate/rhythm strategy
Elevated in HCM acute decompensation; useful for trending decongestion but interpret cautiously (chronic elevation in HCM regardless of acute state)
Hypotension in HCM = SAM-mediated LVOT obstruction collapse — treat with FLUIDS + phenylephrine, NOT inotropes; SBP <90 with HCM precipitant triggers obstruction-crisis pathway
Tachycardia worsens LVOT gradient by shortening diastolic filling; HR target <80 bpm with esmolol IV; new AFib RVR requires emergent rate control or cardioversion
Pulmonary edema secondary to acute diastolic dysfunction + SAM-driven mitral regurgitation — SpO2 < 92% triggers NIPPV (use carefully — avoid pre-load drop)
eGFR for disopyramide (renal-adjusted), mavacamten (CYP-mediated metabolism — not strict renal cutoff but used in monitoring), AC dosing if AF
HypoMg ↑ TdP risk on disopyramide (QT prolongation); maintain Mg ≥2.0
CMR LGE quantifies fibrosis burden — high LGE (>15% LV mass) refines SCD risk upward beyond HCM-RISK-SCD score; identifies apical aneurysm
Major SCD risk modifier in HCM (ESC 2014; ACC/AHA 2024)
* = hard-required. Engine cannot meaningfully run until these are filled.
Severity triggers (5)
- informationallife_threateningsam_mediated_lvot_obstruction_crisis_worsened_by_inotropesHCM patient given inadvertent inotrope (dobutamine, milrinone, epinephrine drip) for hypotension — paradoxically worsens SAM-mediated LVOT obstruction with hemodynamic collapseTrigger could not be auto-evaluated — needs clinician judgement.
- informationallife_threateningnew_afib_with_rvr_destabilizing_diastolic_filling_in_hcmNew-onset AFib with rapid ventricular response in HCM patient — loss of atrial kick + tachycardia → catastrophic drop in LV filling because stiff hypertrophied LV depends on atrial systoleTrigger could not be auto-evaluated — needs clinician judgement.
- informationalsevereseptal_reduction_therapy_decision_for_refractory_obstructionHCM patient with persistent NYHA III-IV symptoms + LVOT gradient ≥50 mmHg at rest or with provocation despite maximally tolerated medical therapy (BB or CCB ± disopyramide ± mavacamten) — septal reduction therapy referralTrigger could not be auto-evaluated — needs clinician judgement.
- informationalseveremavacamten_lvef_drop_below_50pct_during_titrationHCM patient on mavacamten with REMS echo showing LVEF drop <50% during titration — REMS-mandated dose reduction or discontinuationTrigger could not be auto-evaluated — needs clinician judgement.
- informationalsevereunexplained_syncope_or_nsvt_or_high_lge_burden_meeting_icd_criteriaHCM patient with unexplained syncope, NSVT on Holter, family history of SCD, LV thickness ≥30 mm, apical aneurysm on CMR, or high LGE burden (>15% LV mass) — primary-prevention ICD indicationTrigger could not be auto-evaluated — needs clinician judgement.
Workflow calculators
Run this disease's risk and dosing calculators inline.
Recommended regimen
HCM acute decompensation — preload/afterload-dependent: fluids + phenylephrine + esmolol + AVOID inotropes/vasodilators; chronic: BB/CCB/disopyramide → mavacamten → septal reduction therapy (ACC/AHA 2024 HCM)- phenylephrinefirst linepure_alpha_1_agonist_vasopressor50-200 mcg IV bolus or 0.5-3 mcg/kg/min infusion titrate to MAP ≥65 • IV • bolus or continuous infusiontriggers: hcm_acute_decompensation_with_hypotension, sam_mediated_lvot_obstructionPure α-agonist increases afterload → reduces LVOT gradient by improving aortic ejection and abolishing SAM; preferred over norepinephrine (β-component worsens obstruction) and ABSOLUTELY preferred over inotropesrxcui 8163
- esmololfirst linebeta_1_selective_blocker_short_acting500 mcg/kg IV bolus then 50-300 mcg/kg/min infusion titrate to HR <80 • IV • continuous infusiontriggers: hcm_acute_decompensation_with_tachycardia, sam_mediated_lvot_obstruction, new_afib_with_rvr_in_hcmShort-acting cardioselective β-blocker lengthens diastolic filling time, reduces inotropy → reduces LVOT gradient; titratable, off rapidly if hemodynamic compromiserxcui 203222
- metoprolol_tartratefirst linebeta_1_selective_blocker25 mg PO BID titrate to maximally tolerated • PO • BIDtriggers: chronic_hcm_obstructive_or_non_obstructive, transition_from_iv_esmololACC/AHA 2024 HCM Class I — first-line chronic β-blockade for symptomatic HCM; reduces inotropy + lengthens diastolerxcui 203191
- verapamilfirst linenon_dhp_ccb_phenylalkylamine120 mg PO daily extended-release titrate to 480 mg/d max • PO • daily ERtriggers: hcm_intolerant_to_beta_blocker, symptomatic_obstructive_or_non_obstructive_hcmACC/AHA 2024 HCM Class I alternative — non-DHP CCB; CAUTION in obstructive HCM with very high gradient or heart failure (vasodilator effect can worsen gradient — start low)rxcui 11170
- disopyramidesecond lineclass_ia_antiarrhythmic_negative_inotrope40-50 mg PO TID-QID extended-release titrate to 600-800 mg/d max; renal-adjusted • PO • TID-QIDtriggers: symptomatic_obstructive_hcm_refractory_to_bb_or_ccb, sam_with_lvot_gradient_≥50_mmhgACC/AHA 2024 HCM Class IIa — negative inotrope reduces SAM and LVOT gradient; QT prolongation + anticholinergic effects + proarrhythmic — monitor QT, K, Mgrxcui 3541
- mavacamtensecond linecardiac_myosin_inhibitor5 mg PO daily start; titrate q4w per echo per REMS (max 15 mg/d) • PO • dailytriggers: symptomatic_obstructive_hcm_nyha_ii_iii_refractory_to_bb_ccb_or_disopyramide, patient_avoids_septal_reduction_therapyACC/AHA 2024 HCM Class IIa — first-in-class cardiac myosin inhibitor; EXPLORER-HCM PMID 32861276 (Olivotto Lancet 2020): 30% relative improvement in pVO2 + ~47% reduction in resting LVOT gradient; VALOR-HCM 2023: reduces septal reduction therapy referrals; REMS program — echo q4w during titration to detect LVEF drop <50%rxcui 2600867
- apixabancomorbidity specificdoac_factor_xa_direct5 mg PO BID (2.5 mg BID per FDA dose-reduction criteria) • PO • BID indefinitetriggers: any_afib_in_hcm_regardless_of_cha2ds2vascACC/AHA 2024 HCM Class I — ANY AF in HCM = anticoagulate regardless of CHA2DS2-VASc score; DOAC preferred over warfarin; RE-LY/ARISTOTLE/ROCKET-AF/ENGAGE class evidence appliesrxcui 1364430
- rivaroxabancomorbidity specificdoac_factor_xa_direct20 mg PO daily with food (15 mg if CrCl 15-50) • PO • daily indefinitetriggers: any_afib_in_hcm_apixaban_alternativeACC/AHA 2024 HCM Class I — DOAC alternative for AF in HCMrxcui 1114195
- warfarincomorbidity specificvitamin_k_antagonist5 mg PO daily; INR target 2-3 • PO • daily indefinitetriggers: mechanical_valve_or_doac_contraindicated_or_unaffordable_in_hcm_with_afACC/AHA 2024 HCM Class I if DOAC contraindicated; INR 2-3rxcui 11289
outpatient playbook — drug actions (2)
- 1. continue chronic regimen at maximally tolerated doserxcui 20352metoprolol tartrate or verapamil + disopyramide if needed + mavacamten if eligible • PO • as scheduledtrigger: Chronic HCMACC/AHA 2024 HCM Class I/IIa
- 2. continue AC if AFrxcui 1364430apixaban 5 mg PO BID indefinite • PO • BIDtrigger: Any AF in HCMACC/AHA 2024 HCM Class I
Auto-drafted A&P note
outpatientSubjective
- Possible entry pathways: Acute dyspnea / orthopnea / pre-syncope in patient with known HCM (resting or provocable LVOT gradient ≥30 mmHg) — sudden hemodynamic deterioration; Bedside echo: new or worsened SAM-mediated LVOT obstruction with dynamic gradient (rest ≥50 mmHg or with Valsalva/exercise provocation) in HCM patient; New-onset AFib with rapid ventricular response in HCM — loss of atrial kick → catastrophic LV filling drop because stiff hypertrophied LV depends on atrial systole.
Objective
- No vitals, labs, or imaging entered for this encounter.
Assessment
**Hypertrophic cardiomyopathy with acute decompensation** (cardio.acute-hf.hcm-decompensation.v1). Phenotype framing: Obstructive (HOCM, resting or provocable gradient ≥30 mmHg) vs non-obstructive vs apical HCM vs end-stage dilated phenotype (rare 5% with LVEF <50% — classic ADHF GDMT applies); exclude phenocopies (TTR amyloid, Fabry, Danon, athlete heart, hypertensive HD) Scope: Acute decompensation in HCM = dynamic LVOT obstruction (SAM-driven) + diastolic dysfunction + often AFib — preload/afterload-dependent. Treatment paradox vs ADHF: give fluids, give phenylephrine, slow HR with esmolol, AVOID inotropes / vasodilators / aggressive diuresis No severity triggers fired against current inputs.
Plan
Regimen axis: **HCM acute decompensation — preload/afterload-dependent: fluids + phenylephrine + esmolol + AVOID inotropes/vasodilators; chronic: BB/CCB/disopyramide → mavacamten → septal reduction therapy (ACC/AHA 2024 HCM)**. 1. phenylephrine 50-200 mcg IV bolus or 0.5-3 mcg/kg/min infusion titrate to MAP ≥65 IV bolus or continuous infusion (pure_alpha_1_agonist_vasopressor, first line) — Pure α-agonist increases afterload → reduces LVOT gradient by improving aortic ejection and abolishing SAM; preferred over norepinephrine (β-component worsens obstruction) and ABSOLUTELY preferred over inotropes 2. esmolol 500 mcg/kg IV bolus then 50-300 mcg/kg/min infusion titrate to HR <80 IV continuous infusion (beta_1_selective_blocker_short_acting, first line) — Short-acting cardioselective β-blocker lengthens diastolic filling time, reduces inotropy → reduces LVOT gradient; titratable, off rapidly if hemodynamic compromise 3. metoprolol_tartrate 25 mg PO BID titrate to maximally tolerated PO BID (beta_1_selective_blocker, first line) — ACC/AHA 2024 HCM Class I — first-line chronic β-blockade for symptomatic HCM; reduces inotropy + lengthens diastole 4. verapamil 120 mg PO daily extended-release titrate to 480 mg/d max PO daily ER (non_dhp_ccb_phenylalkylamine, first line) — ACC/AHA 2024 HCM Class I alternative — non-DHP CCB; CAUTION in obstructive HCM with very high gradient or heart failure (vasodilator effect can worsen gradient — start low) 5. disopyramide 40-50 mg PO TID-QID extended-release titrate to 600-800 mg/d max; renal-adjusted PO TID-QID (class_ia_antiarrhythmic_negative_inotrope, second line) — ACC/AHA 2024 HCM Class IIa — negative inotrope reduces SAM and LVOT gradient; QT prolongation + anticholinergic effects + proarrhythmic — monitor QT, K, Mg 6. mavacamten 5 mg PO daily start; titrate q4w per echo per REMS (max 15 mg/d) PO daily (cardiac_myosin_inhibitor, second line) — ACC/AHA 2024 HCM Class IIa — first-in-class cardiac myosin inhibitor; EXPLORER-HCM PMID 32861276 (Olivotto Lancet 2020): 30% relative improvement in pVO2 + ~47% reduction in resting LVOT gradient; VALOR-HCM 2023: reduces septal reduction therapy referrals; REMS program — echo q4w during titration to detect LVEF drop <50% 7. apixaban 5 mg PO BID (2.5 mg BID per FDA dose-reduction criteria) PO BID indefinite (doac_factor_xa_direct, comorbidity specific) — ACC/AHA 2024 HCM Class I — ANY AF in HCM = anticoagulate regardless of CHA2DS2-VASc score; DOAC preferred over warfarin; RE-LY/ARISTOTLE/ROCKET-AF/ENGAGE class evidence applies 8. rivaroxaban 20 mg PO daily with food (15 mg if CrCl 15-50) PO daily indefinite (doac_factor_xa_direct, comorbidity specific) — ACC/AHA 2024 HCM Class I — DOAC alternative for AF in HCM 9. warfarin 5 mg PO daily; INR target 2-3 PO daily indefinite (vitamin_k_antagonist, comorbidity specific) — ACC/AHA 2024 HCM Class I if DOAC contraindicated; INR 2-3 Setting playbook (outpatient) — Long-term HCM management: HCM specialist clinic q3-6 mo; mavacamten REMS echo q12w maintenance; annual Holter for NSVT; cardiac MRI q3-5y; cascade family screening; ICD/septal reduction therapy if escalation needed; AC continuation for AF 10. continue chronic regimen at maximally tolerated dose metoprolol tartrate or verapamil + disopyramide if needed + mavacamten if eligible PO as scheduled — Chronic HCM (ACC/AHA 2024 HCM Class I/IIa) 11. continue AC if AF apixaban 5 mg PO BID indefinite PO BID — Any AF in HCM (ACC/AHA 2024 HCM Class I) Non-pharmacologic actions: - Sports clearance reassessment annually - Cascade family screening - ICD/septal reduction reassessment if symptomatic progression - Pregnancy planning specialist referral if applicable AVOID / contraindication checks: - Absolute_contraindication_dobutamine_milrinone_epinephrine_in_hcm_obstruction (worsens SAM and LVOT gradient — never give inotropes for HCM hypotension) - Absolute_contraindication_nitroglycerin_acei_arb_arni_in_acute_hcm_obstruction (vasodilator drops afterload → worsens LVOT gradient) - Caution_aggressive_diuresis_in_hcm (drops preload → worsens LVOT gradient; use small doses only if frank pulmonary edema) - Caution_dhp_ccb_amlodipine_in_hcm_obstructive (vasodilator effect worsens gradient — use non DHP only) - Disopyramide_qt_monitoring_required_with_k_and_mg_repletion (proarrhythmic if hypoK / hypoMg) - Mavacamten_rems_echo_lvef_monitoring_q4w_during_titration_then_q12w_maintenance (LVEF drop <50% → dose reduction or discontinuation) - Mavacamten_avoid_with_strong_cyp3a4_inhibitors_or_inducers (clarithromycin, ketoconazole, rifampin — drug interaction algorithm in REMS) - Decision:any_af_in_hcm_class_i_anticoagulation_regardless_of_cha2ds2vasc (ACC/AHA 2024 HCM) - Decision:septal_reduction_therapy_at_experienced_center_for_lvot_gradient_≥50_mmhg_nyha_iii_iv_refractory_to_medical_therapy (Class I) - Decision:icd_for_primary_prevention_per_esc_2014_hcm_risk_score_5pct_5y_or_acc_aha_2024_modifiers (LGE, family history SCD, syncope, NSVT, apical aneurysm, LV thickness ≥30 mm)
Monitoring
Regimen monitoring: - continuous ecg telemetry for af and vt vf surveillance (Class I) - echo q4w during mavacamten titration per rems (FDA label) - echo q12w maintenance on mavacamten (REMS) - qt interval baseline then q3d during disopyramide titration then quarterly (FDA label) - k and mg repletion to above 4.0 and above 2.0 (proarrhythmia prevention) - cmr with lge at diagnosis then q3 5y for fibrosis progression (ACC/AHA 2024) - holter 24 48h at baseline and q1 2y for nsvt scd modifier (ESC 2014; ACC/AHA 2024) - cascade family screening q3 5y or at genetic test completion (ESC 2014; ACC/AHA 2024) Setting (outpatient) monitoring: - Echo q3-6 mo or q12w on mavacamten maintenance - Holter q1-2y - Cardiac MRI q3-5y - Annual SCD risk reassessment Follow-up plan: HCM specialist clinic within 1-2 weeks; cascade family screening (genetic counseling); mavacamten REMS echo q4w during titration then q12w maintenance; ICD/septal reduction decision finalised; sports clearance shared decision; cardiac rehab if NYHA II-III - Close-out criterion: long-term plan + family screening + follow-up cadence finalised Monitoring phase: Telemetry continuous (VT/VF surveillance + AFib detection); daily echo if mavacamten initiation (REMS — LVEF q4w during titration to detect drop <50%); BMP daily; QT on disopyramide; if AFib AC therapeutic; serial Holter for NSVT (SCD modifier)
Disposition
Current setting: outpatient — Long-term HCM management: HCM specialist clinic q3-6 mo; mavacamten REMS echo q12w maintenance; annual Holter for NSVT; cardiac MRI q3-5y; cascade family screening; ICD/septal reduction therapy if escalation needed; AC continuation for AF Disposition criteria: - Indefinite HCM specialist follow-up; lifelong AC if AF; ICD if SCD criteria met; mavacamten or septal reduction per individual response Escalation triggers (move to higher acuity): - Symptomatic progression → escalate medical therapy or septal reduction therapy - New VT/VF or syncope → urgent EP / ICD evaluation - New AF → AC initiation - End-stage dilated phenotype (LVEF <50%) → switch to cardio.hfref.core.v1 for GDMT 4-pillar
Earlier-Return Triggers
Return-precaution thresholds (watch for): - [LIFE_THREATENING] HCM patient given inadvertent inotrope (dobutamine, milrinone, epinephrine drip) for hypotension — paradoxically worsens SAM-mediated LVOT obstruction with hemodynamic collapse - [LIFE_THREATENING] New-onset AFib with rapid ventricular response in HCM patient — loss of atrial kick + tachycardia → catastrophic drop in LV filling because stiff hypertrophied LV depends on atrial systole - [SEVERE] HCM patient with persistent NYHA III-IV symptoms + LVOT gradient ≥50 mmHg at rest or with provocation despite maximally tolerated medical therapy (BB or CCB ± disopyramide ± mavacamten) — septal reduction therapy referral
Citations
- ACC/AHA 2024 HCM Guideline + ESC 2023 cardiomyopathies (Arbelo) + ESC 2014 HCM (Elliott) for SCD risk [PMID:37622666](https://pubmed.ncbi.nlm.nih.gov/37622666/) - Cited evidence (PMID 25173338) [PMID:25173338](https://pubmed.ncbi.nlm.nih.gov/25173338/) - Cited evidence (PMID 32861276) [PMID:32861276](https://pubmed.ncbi.nlm.nih.gov/32861276/) - Cited evidence (PMID 38587234) [PMID:38587234](https://pubmed.ncbi.nlm.nih.gov/38587234/) - Cited evidence (PMID 23223539) [PMID:23223539](https://pubmed.ncbi.nlm.nih.gov/23223539/) Last reconciled with current guidelines: 2026-05-15.
- ACC/AHA 2024 HCM Guideline + ESC 2023 cardiomyopathies (Arbelo) + ESC 2014 HCM (Elliott) for SCD risk — PMID:37622666
- Cited evidence (PMID 25173338) — PMID:25173338
- Cited evidence (PMID 32861276) — PMID:32861276
- Cited evidence (PMID 38587234) — PMID:38587234
- Cited evidence (PMID 23223539) — PMID:23223539