26/11/2025
π« Dagger Q Waves in HOCM β Complete Clinical Note
π What Are Dagger Q Waves?
β’ Deep, narrow, sharp Q waves β look like a tiny βstab markβ on ECG.
β’ Most common in I, aVL, V5βV6 (lateral leads).
β’ Can appear in II, III, aVF or V3βV4 in apical/septal variants.
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π¬ Why Do They Happen? (Pathophysiology)
β’ Asymmetric septal or apical hypertrophy alters early ventricular depolarization β electrical vector shifts β initial deep negative deflection.
β’ This creates a pseudoinfarct pattern β looks like MI, but isnβt.
β’ Myocardial disarray + micro-fibrosis β further exaggerate the depth of Q waves.
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π©Ί How to Distinguish From MI Q Waves
β’ HOCM Q waves:
β‘οΈ Deep but thin
β‘οΈ Narrow (40 ms)
β‘οΈ Flatter, wider
β‘οΈ Matches coronary territory
β‘οΈ Clinical ischemic history present
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π‘ When to Suspect HOCM Instead of MI
β’ Young patient with no risk factors
β’ Family history of SCD or HCM
β’ LVH voltage + dagger Qs + T inversions
β’ Dynamic symptoms: exertional syncope, dyspnea, palpitations
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π₯οΈ Imaging & Investigations
β’ Echo:
β Asymmetric septal hypertrophy
β LVOT gradient
β Systolic anterior motion (SAM) of mitral valve
β’ Cardiac MRI:
β LGE for fibrosis
β Differentiates scar vs pseudoinfarct
β’ Holter / Event monitor:
β Detect NSVT, AF
β’ Exercise stress test:
β Evaluate dynamic obstruction
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π©Ή Treatment & Management of HOCM
1οΈβ£ Lifestyle / Activity
β’ Avoid dehydration π±
β’ Avoid high-intensity competitive sports πββοΈπ₯
β’ Avoid vasodilators & high-dose diuretics (may worsen obstruction)
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2οΈβ£ Medications
**β’ Beta-blockers (first-line):
β Metoprolol / Atenolol
β Slow HR, reduce obstruction, improve symptoms
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**β’ Non-dihydropyridine CCBs:
β Verapamil / Diltiazem
β Alternative if BB not tolerated
**β’ Disopyramide:
β Reduces LVOT gradient
β Often combined with beta-blocker
β οΈ Watch for anticholinergic effects
β’ Treat AF aggressively β beta-blocker, amiodarone, anticoagulation
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3οΈβ£ Invasive Options (For Symptomatic Obstruction)
β’ Septal Myectomy (gold standard)
β Excellent symptom improvement
β Consider in LVOT gradient >50 mmHg despite meds
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β’ Alcohol Septal Ablation
β Non-surgical alternative
β For selected patients
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4οΈβ£ ICD (Implantable Cardioverter-Defibrillator)
Indications:
β’ Prior cardiac arrest / sustained VT
β’ Massive LVH (>30 mm)
β’ Family history of sudden cardiac death
β’ Unexplained syncope
β’ Extensive LGE on MRI
β οΈπ₯ Life-saving in high-risk patients
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5οΈβ£ Follow-Up
β’ Annual echo
β’ Holter monitoring
β’ Family screening (1st-degree relatives)
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π― Ultimate Summary
Dagger Q waves = deep, narrow, sharp Q waves caused by altered septal/apical activation in HOCM.
They mimic MI but are usually thin, found in younger patients, and accompany LVH + T-wave inversions.
Management involves beta-blockers, verapamil, disopyramide, and septal reduction therapy for severe obstruction, plus ICD for high-risk patients.
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