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Give me 10 common heart disease with ecg interpretation

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I now have excellent content and ECG images. Here is a comprehensive, textbook-sourced answer:

10 Common Heart Diseases with ECG Interpretation

1. ST-Elevation Myocardial Infarction (STEMI)

What it is: Complete occlusion of a coronary artery causing full-thickness myocardial necrosis.
ECG Findings:
  • Hyperacute T waves - earliest change (tall, broad T waves in affected territory)
  • ST-segment elevation ≥1 mm in ≥2 contiguous limb leads, or ≥2 mm in ≥2 contiguous precordial leads
  • Reciprocal ST depression in mirror leads (e.g., inferior STEMI shows elevation in II, III, aVF with reciprocal depression in I, aVL)
  • Pathological Q waves - develop within hours to days (>40 ms wide, >25% of R wave height)
  • T-wave inversion in the subacute phase
Territory localization:
TerritoryCulpritECG leads
InferiorRCAII, III, aVF
AnteriorLADV1-V4
LateralLCxI, aVL, V5-V6
PosteriorRCA/LCxTall R in V1-V2, ST depression V1-V3
Source: Harrison's Principles of Internal Medicine 22E; Tintinalli's Emergency Medicine

2. Non-ST-Elevation Myocardial Infarction (NSTEMI) / Unstable Angina

What it is: Partial coronary occlusion or severe stenosis causing subendocardial ischemia.
ECG Findings:
  • ST depression ≥0.5 mm (horizontal or downsloping) in ≥2 contiguous leads
  • T-wave inversion - symmetric, deep (Wellens' pattern in proximal LAD stenosis)
  • Transient ST elevation possible
  • Normal ECG in up to 30% of confirmed NSTEMI cases
Key point: The distinction from STEMI is the absence of persistent ST elevation. Biomarkers (troponin) are needed to separate NSTEMI from unstable angina.
Source: Goldman-Cecil Medicine; Tintinalli's Emergency Medicine

3. Atrial Fibrillation (AF)

What it is: Disorganized atrial electrical activity with irregularly irregular ventricular response.
ECG Findings:
  • Absent P waves - replaced by chaotic fibrillatory baseline (f waves, best seen in V1)
  • Irregularly irregular RR intervals - hallmark finding
  • Narrow QRS complexes (unless aberrant conduction or bundle branch block present)
  • Ventricular rate typically 100-160 bpm if uncontrolled
  • Coarse vs. fine fibrillation - coarse f waves >1 mm, fine f waves <1 mm
Associated ECG clues: Right axis deviation + R/S ratio >1 in V1 + ST depression V1-V3 suggests underlying pulmonary hypertension as the cause.
Source: Tintinalli's Emergency Medicine; Schwartz's Principles of Surgery

4. Atrioventricular (AV) Block

What it is: Impaired conduction between atria and ventricles at the AV node or His-Purkinje system.
Examples of AV block ECG patterns - A: First-degree, B: Mobitz I (Wenckebach), C: Mobitz II, D: 2:1 AV block, E: Complete heart block
Figure: AV block types A-E - Washington Manual of Medical Therapeutics
ECG Findings by Degree:
DegreeECG Pattern
1st degreePR interval >200 ms, every P conducts
2nd degree Mobitz I (Wenckebach)Progressive PR lengthening until P wave is dropped, then resets; "group beating"; RR intervals shorten before dropped beat
2nd degree Mobitz IIFixed PR interval with sudden non-conducted P waves; often associated with bundle branch block; high risk of progression to complete block
3rd degree (complete)Complete AV dissociation - atrial rate and ventricular rate are independent; escape rhythm is ventricular (wide, slow ~30-40 bpm) or junctional (~40-60 bpm)
Source: Washington Manual of Medical Therapeutics; Frameworks for Internal Medicine; Fuster and Hurst's The Heart, 15th Ed.

5. Ventricular Tachycardia (VT)

What it is: Three or more consecutive ventricular beats at rate >100 bpm originating below the bundle of His.
ECG Findings:
  • Wide QRS complexes (>120 ms) - monomorphic or polymorphic
  • Regular rhythm in monomorphic VT (rate typically 140-200 bpm)
  • AV dissociation - independent P waves marching through at a slower rate (pathognomonic when present)
  • Fusion beats - when a sinus beat and ventricular beat merge (pathognomonic)
  • Capture beats - rare normally-conducted beats during VT
  • Concordance - all precordial leads (V1-V6) either all positive (positive concordance) or all negative (negative concordance) strongly favors VT over SVT with aberrancy
Brugada criteria: Used to distinguish VT from SVT with aberrancy on 12-lead ECG.
Source: Goldman-Cecil Medicine; ROSEN's Emergency Medicine; Braunwald's Heart Disease

6. Acute Pericarditis / Pericardial Effusion with Tamponade

What it is: Inflammation of the pericardial sac ± fluid accumulation causing hemodynamic compromise.
Electrical alternans in pericardial tamponade - QRS amplitude alternates beat-to-beat
Figure: Electrical alternans in pericardial tamponade - Roberts and Hedges' Clinical Procedures in Emergency Medicine
ECG Findings - Pericarditis (4 stages):
  1. Stage 1: Diffuse ST elevation (saddle-shaped, concave up) + PR depression in most leads; PR elevation in aVR
  2. Stage 2: ST and PR normalization
  3. Stage 3: Diffuse T-wave inversion
  4. Stage 4: T-wave normalization
ECG Findings - Pericardial Effusion/Tamponade:
  • Sinus tachycardia - most common finding
  • PR depression ≥1 mV in ≥1 lead (other than aVR)
  • Low-voltage QRS - amplitude ≤5 mm across all limb leads (with moderate to large effusions)
  • Electrical alternans - beat-to-beat alternation in QRS amplitude/axis (classic for tamponade, due to swinging heart within fluid)
Source: Roberts and Hedges' Clinical Procedures in Emergency Medicine

7. Hypertrophic Cardiomyopathy (HCM)

What it is: Genetic sarcomere mutation causing asymmetric left ventricular hypertrophy, especially the septum.
ECG Findings:
  • Left ventricular hypertrophy (LVH) - increased voltage (Sokolow-Lyon: S in V1 + R in V5/V6 >35 mm)
  • Deep, narrow Q waves in inferolateral leads (II, III, aVF, V4-V6) - due to septal hypertrophy; can mimic ischemia
  • Giant negative T waves in mid-precordial leads (classic apical HCM variant)
  • Left axis deviation
  • ST depression and T-wave inversion in lateral leads
  • ECG is abnormal in ~95% of patients with HCM
Diagnostic clue: Q waves in HCM are narrow (<40 ms) compared to the wide Q waves of infarction. The combination of deep Q waves + high voltage + no history of infarction should raise HCM suspicion.
Source: Goldman-Cecil Medicine; Braunwald's Heart Disease

8. Wolff-Parkinson-White Syndrome (WPW)

What it is: Accessory pathway (Bundle of Kent) bypassing the AV node, causing pre-excitation.
ECG Findings (Classic triad on resting ECG):
  • Short PR interval (<120 ms) - rapid conduction via accessory pathway
  • Delta wave - slurred upstroke of the QRS (pre-excitation of ventricular myocardium)
  • Wide QRS (>120 ms) - due to fusion of delta wave + normal conduction
  • Secondary ST-T changes discordant to the delta wave/QRS direction
During tachycardia (AVRT):
  • Orthodromic AVRT - narrow QRS (anterograde via AV node, retrograde via accessory pathway)
  • Antidromic AVRT - very rapid, wide-complex tachycardia resembling VT (anterograde via accessory pathway)
  • AF with WPW - irregular, very fast (>200 bpm), wide bizarre QRS complexes - life-threatening
Source: Tintinalli's Emergency Medicine; Braunwald's Heart Disease

9. Right Heart Strain / Cor Pulmonale (Pulmonary Embolism)

What it is: Acute or chronic right ventricular pressure overload from pulmonary pathology (PE, pulmonary hypertension, COPD).
ECG Findings - Acute PE (classic but insensitive):
  • S1Q3T3 pattern - large S wave in lead I, Q wave in lead III, inverted T in lead III
  • Sinus tachycardia - most common finding in PE (~40% of cases)
  • New right bundle branch block (complete or incomplete)
  • Right axis deviation
  • ST depression/T-wave inversion V1-V3 (right ventricular strain)
  • Atrial fibrillation - 10-35% of PE patients, more common in those >60 years old
ECG Findings - Chronic cor pulmonale:
  • R/S ratio >1 in V1
  • Right axis deviation
  • ST depression V1-V3
Source: Tintinalli's Emergency Medicine

10. Dilated Cardiomyopathy (DCM)

What it is: Impaired ventricular contraction with ventricular dilation, often idiopathic or from ischemia/viral myocarditis.
ECG Findings:
  • Left bundle branch block (LBBB) - wide QRS (>120 ms), broad notched R in I, aVL, V5-V6; QS in V1
  • Nonspecific ST-T changes - most common; diffuse flat or inverted T waves
  • Low voltage QRS complexes
  • Atrial fibrillation - very common with progressive disease
  • Left atrial enlargement - broad bifid P waves (P mitrale) in lead II; negative terminal component of P in V1
  • Sinus tachycardia - compensatory
  • Ventricular arrhythmias - premature ventricular complexes, non-sustained VT
Source: Braunwald's Heart Disease; Tintinalli's Emergency Medicine

Quick Reference Summary Table

#ConditionKey ECG Finding
1STEMIST elevation + Q waves in territory
2NSTEMI/UAST depression + T-wave inversion
3Atrial FibrillationNo P waves, irregularly irregular
4AV BlockPR prolongation / dropped beats / AV dissociation
5Ventricular TachycardiaWide QRS, AV dissociation, fusion beats
6Pericarditis / TamponadeDiffuse ST elevation (saddle-shaped) / electrical alternans
7Hypertrophic CardiomyopathyLVH + deep narrow Q waves inferolateral
8WPWShort PR + delta wave + wide QRS
9Pulmonary EmbolismS1Q3T3 + sinus tachycardia + RV strain
10Dilated CardiomyopathyLBBB + low voltage + AF
Sources: Braunwald's Heart Disease (12th Ed.), Harrison's Principles of Internal Medicine (22E), Goldman-Cecil Medicine, Tintinalli's Emergency Medicine, Washington Manual of Medical Therapeutics, Roberts and Hedges' Clinical Procedures in Emergency Medicine, Fuster and Hurst's The Heart (15th Ed.)

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I now have all the ECG images needed. Here is the complete guide with real textbook ECG tracings for all 10 conditions:

10 Common Heart Diseases with ECG Interpretation + Images

1. ST-Elevation Myocardial Infarction (STEMI)

Key ECG findings: ST elevation in a coronary territory, reciprocal depression, eventual Q waves and T-wave inversion.
Anterior STEMI - ST segment elevation in V1-V4 with obliquely straight morphology, confirmed 90% LAD stenosis
Anterior wall STEMI: ST elevation in V1-V4. Emergency cath confirmed 90% LAD stenosis. - ROSEN's Emergency Medicine
Anterolateral STEMI - ST elevation in V2-V6, I, and aVL due to in-stent LAD thrombosis
Anterolateral STEMI: STE in V2-V6, I, and aVL. Prior LAD stent with 100% in-stent thrombosis found at cath. - ROSEN's Emergency Medicine
TerritoryLeads with STECulprit Artery
AnteriorV1-V4LAD
AnterolateralV1-V6, I, aVLProximal LAD
InferiorII, III, aVFRCA
LateralI, aVL, V5-V6LCx
PosteriorTall R in V1-V2, ST depressionRCA/LCx

2. NSTEMI / Unstable Angina

Key ECG findings: ST depression, T-wave inversion, or normal ECG (no persistent ST elevation). Troponin distinguishes NSTEMI from UA.
  • ST depression ≥0.5 mm (horizontal or downsloping) in ≥2 contiguous leads
  • Symmetric T-wave inversion (Wellens' sign in V2-V3 = proximal LAD stenosis)
  • Transient ST elevation possible during pain
  • Up to 30% have a normal ECG at presentation
Note: The ECG alone cannot rule out NSTEMI - serial troponins are required.

3. Atrial Fibrillation (AF)

Key ECG findings: Absent P waves, chaotic baseline, irregularly irregular rhythm.
Atrial fibrillation - three examples showing absent P waves and irregularly irregular ventricular response
Three examples of atrial fibrillation with irregular ventricular response (A, B, C). Note the absent P waves and chaotic baseline. - Tintinalli's Emergency Medicine
Full 12-lead ECG of atrial fibrillation - no discernible P waves, disorganized atrial activation best seen in V1
12-lead ECG of AF: Irregularly irregular rhythm without discernible P waves. Disorganized atrial activation best seen in V1. - Harrison's Principles of Internal Medicine 22E
ECG Hallmarks:
  • No distinct P waves (replaced by fibrillatory f-waves, best in V1)
  • Irregularly irregular RR intervals
  • Narrow QRS (unless aberrancy present)
  • Ventricular rate 120-170 bpm if AV node intact

4. AV Block (1st, 2nd, 3rd Degree)

Key ECG findings: Vary by degree - PR prolongation, dropped beats, or complete AV dissociation.
AV block examples A-E: First-degree, Mobitz I Wenckebach, Mobitz II, 2:1 block, and complete heart block
A: First-degree AV block (PR >200 ms). B: Mobitz I - progressive PR lengthening then dropped beat. C: Mobitz II - abrupt dropped beat, fixed PR. D: 2:1 AV block. E: Complete heart block - independent atrial and ventricular rhythms. - Washington Manual of Medical Therapeutics
TypeECG PatternRisk
1st degreePR >200 ms, all P waves conductBenign
2nd degree Mobitz IProgressive PR lengthening → dropped beat ("group beating")Usually benign
2nd degree Mobitz IIFixed PR, sudden non-conducted P waves; often with BBBHigh - may progress to 3rd degree
3rd degree (complete)Complete AV dissociation; independent P and QRS ratesLife-threatening

5. Ventricular Tachycardia (VT)

Key ECG findings: Wide-complex regular tachycardia, AV dissociation, fusion/capture beats.
Monomorphic and polymorphic ventricular tachycardia - three examples (A: 270 bpm, B: 220 bpm, C: 180 bpm with torsades)
A: Monomorphic VT at 270 bpm with uniform wide QRS. B: Monomorphic VT at 220 bpm. C: Polymorphic VT (torsades de pointes) - note twisting of the QRS axis. - Tintinalli's Emergency Medicine
ECG Criteria for VT:
FeatureFinding
QRS width>120 ms (wide complex)
Rate140-300 bpm, usually regular
AV dissociationP waves marching independently (pathognomonic)
Fusion beatsHybrid sinus + ventricular beat (pathognomonic)
ConcordanceAll V1-V6 positive or all negative
AxisExtreme right axis deviation ("northwest axis")
  • Monomorphic VT: Uniform QRS morphology beat-to-beat; rate 140-180 bpm typically
  • Polymorphic VT / Torsades: Varying QRS morphology, "twisting points"; associated with prolonged QT

6. Acute Pericarditis / Cardiac Tamponade

Key ECG findings: Diffuse saddle-shaped ST elevation + PR depression (pericarditis); electrical alternans + low voltage (tamponade).
Acute pericarditis ECG - diffuse ST elevation and PR depression in non-territory-specific distribution; aVR shows ST depression and PR elevation
Acute pericarditis (Stage I): Diffuse ST elevation with concordant PR depression in non-territory distribution. aVR shows ST depression + PR elevation. - Fuster and Hurst's The Heart, 15th Ed.
Pericarditis ECG from Braunwald's - diffuse ST elevation and PR segment depression
ECG in acute pericarditis: Diffuse ST-segment elevation and PR-segment depression. - Braunwald's Heart Disease
Electrical alternans in cardiac tamponade - beat-to-beat alternation of QRS amplitude across all leads
Electrical alternans in pericardial tamponade: Beat-to-beat alternation of QRS amplitude due to the heart swinging in the pericardial fluid. - Roberts and Hedges' Clinical Procedures in Emergency Medicine
Pericarditis vs. STEMI:
FeaturePericarditisSTEMI
ST shapeConcave up (saddle-shaped)Convex (tombstone)
DistributionDiffuse, all leadsLocalized to territory
Reciprocal changesNonePresent
PR depressionYesNo
Q wavesNoDevelop over hours

7. Hypertrophic Cardiomyopathy (HCM)

Key ECG findings: LVH voltage, deep narrow Q waves in inferolateral leads, ST-T changes. Abnormal in ~95% of HCM patients.
  • High voltage (Sokolow-Lyon: S-V1 + R-V5/V6 >35 mm)
  • Deep, narrow Q waves in II, III, aVF, V4-V6 (septal hypertrophy; mimics inferior infarct but Q waves are narrow <40 ms)
  • Giant negative T waves in mid-precordial leads (apical variant HCM)
  • Left axis deviation
  • ST depression and T-wave inversion in lateral leads
  • Q waves in HCM: narrow and deep. Q waves in infarction: wide (>40 ms) and associated with R-wave loss
Source: Goldman-Cecil Medicine; Braunwald's Heart Disease

8. Wolff-Parkinson-White Syndrome (WPW)

Key ECG findings (resting): Short PR + delta wave + wide QRS = the classic triad.
WPW preexcitation ECG - baseline showing delta waves, compared to increased preexcitation with atrial pacing at 300 ms
Left panel: Baseline preexcitation in WPW with visible delta waves. Right panel: Increased preexcitation with atrial pacing at 300 ms - note massive widening of QRS as more conduction goes through the accessory pathway. - Fuster and Hurst's The Heart, 15th Ed.
ECG Triad:
  1. Short PR interval (<120 ms) - accessory pathway bypasses AV node delay
  2. Delta wave - slurred, widened upstroke at beginning of QRS
  3. Widened QRS (>120 ms) - fusion of delta + normal conduction
During tachycardia:
  • Orthodromic AVRT: Narrow complex, regular (~200 bpm) - most common
  • Antidromic AVRT: Very wide complex, mimics VT
  • AF with WPW: Extremely rapid (>250 bpm), irregular, bizarre wide complexes - life-threatening (risk of VF)

9. Pulmonary Embolism / Right Heart Strain

Key ECG findings: Sinus tachycardia is most common. Classic S1Q3T3 is specific but insensitive.
  • Sinus tachycardia - most frequent finding (~40% of PE cases)
  • S1Q3T3 - large S wave in lead I, Q wave in lead III, inverted T wave in lead III
  • New right bundle branch block (complete or incomplete)
  • Right axis deviation
  • T-wave inversion V1-V3 - right ventricular strain pattern
  • Atrial fibrillation - occurs in 10-35% of PE patients, more common in elderly
Important caveat: A normal ECG does not rule out PE. The ECG is most useful to exclude other diagnoses (e.g., STEMI, pericarditis).

10. Dilated Cardiomyopathy (DCM)

Key ECG findings: LBBB, diffuse ST-T changes, low voltage, frequent AF.
Dilated cardiomyopathy ECG - diffuse nonspecific ST-T changes with left bundle branch block pattern and low voltage in limb leads
ECG in aVR ST elevation with left main disease - ST elevation aVR with widespread ST depression in setting of diffuse ischemia/cardiomyopathy. - ROSEN's Emergency Medicine
ECG Findings:
  • Left bundle branch block (LBBB): QRS >120 ms; broad notched R in I, aVL, V5-V6; QS pattern in V1 (most common and clinically significant finding)
  • Nonspecific ST-T changes: Diffuse flat or inverted T waves
  • Low voltage QRS: ≤5 mm in all limb leads
  • Atrial fibrillation: Very common with progressive dilation
  • Left atrial enlargement: Broad bifid P waves (P mitrale) in lead II; negative terminal deflection in V1
  • Ventricular arrhythmias: PVCs, non-sustained VT

Quick-Reference Summary Table

#ConditionPathognomonic / Key ECG Sign
1STEMIST elevation in a coronary territory + reciprocal depression
2NSTEMI/UAST depression + T-wave inversion; may be normal
3Atrial FibrillationNo P waves + irregularly irregular RR
4AV BlockPR prolongation / dropped beats / AV dissociation
5Ventricular TachycardiaWide QRS + AV dissociation + fusion beats
6Pericarditis / TamponadeDiffuse saddle ST + PR depression / electrical alternans
7Hypertrophic CardiomyopathyLVH + deep narrow Q waves in inferolateral leads
8WPWShort PR + delta wave + wide QRS
9Pulmonary EmbolismSinus tachycardia + S1Q3T3 + RV strain V1-V3
10Dilated CardiomyopathyLBBB + low voltage + AF
Sources: Braunwald's Heart Disease (12th Ed.), Harrison's Principles of Internal Medicine 22E, Goldman-Cecil Medicine, Tintinalli's Emergency Medicine, ROSEN's Emergency Medicine, Washington Manual of Medical Therapeutics, Fuster and Hurst's The Heart (15th Ed.), Roberts and Hedges' Clinical Procedures in Emergency Medicine
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