ECG Analysis - Attached Tracing

10 Heart Diseases: ECG Changes, Diagnosis & Treatment

1. ST-Elevation Myocardial Infarction (STEMI)

• Hyperacute tall T-waves (earliest sign)
• ST-segment elevation ≥1 mm in 2 contiguous limb leads or ≥2 mm in precordial leads
• Pathological Q waves (>25% of R-wave height, >40 ms wide) develop within hours to days
• Reciprocal ST depression in opposite leads
• Localization: Anterior (V1-V4), Inferior (II, III, aVF), Lateral (I, aVL, V5-V6), Posterior (reciprocal ST depression V1-V3 + tall R in V1)

• Dual antiplatelet therapy: Aspirin 300 mg loading + Ticagrelor 180 mg or Clopidogrel 600 mg
• Anticoagulation: Heparin (UFH or enoxaparin)
• Primary PCI within 90 minutes (door-to-balloon) - gold standard
• Thrombolysis (Streptokinase/Tenecteplase) if PCI not available within 120 min
• Beta-blocker (Metoprolol), ACE inhibitor (Ramipril), Statin (Atorvastatin 80 mg)

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

• ST depression (horizontal or downsloping) in ischemic leads
• T-wave inversions (deep, symmetric - Wellens pattern in LAD territory: V1-V4)
• No pathological Q waves
• May have transient ST elevation that resolves
• ECG may be completely normal in 5-10% of cases

• Aspirin + P2Y12 inhibitor (Ticagrelor preferred)
• Anticoagulation: Fondaparinux (preferred) or enoxaparin
• Early invasive strategy (coronary angiography within 24-72 hrs) for high-risk
• Beta-blocker, Statin, ACE inhibitor long-term
• Nitrates for symptom relief

3. Left Bundle Branch Block (LBBB) - as seen in the attached ECG

• QRS duration ≥120 ms (broad)
• Dominant broad R-wave in I, aVL, V5, V6 (often notched/slurred - "M" shape)
• rS or QS pattern in V1 (deep S-wave or QS)
• Absence of septal Q waves in lateral leads
• Secondary ST-T discordance: T-wave opposite to last QRS deflection
• Left axis deviation common

• Treat underlying cause (ischemia, hypertension, cardiomyopathy, valvular disease)
• New LBBB with ACS: treat as STEMI - emergency PCI
• Cardiac resynchronization therapy (CRT) for LBBB + HFrEF (EF ≤35%) + QRS ≥150 ms
• Pacemaker if associated with complete heart block

4. Atrial Fibrillation (AF)

• Irregularly irregular rhythm (no two R-R intervals are the same)
• Absent P-waves - replaced by fibrillatory (f) waves (chaotic baseline, best seen in V1, II)
• Variable ventricular rate (usually 100-160 bpm if uncontrolled)
• Normal QRS complex (unless aberrant conduction or WPW)

• Rate control: Beta-blockers (Metoprolol), CCBs (Diltiazem), Digoxin (for HF)
• Rhythm control: DC cardioversion (if <48 hrs or anticoagulated), Flecainide, Amiodarone
• Anticoagulation: CHA₂DS₂-VASc score guides use of DOACs (Apixaban, Rivaroxaban) or Warfarin
• Catheter ablation for paroxysmal AF refractory to drugs

5. Complete Heart Block (Third-Degree AV Block)

• Complete AV dissociation: P-waves and QRS have no relationship to each other
• P-wave rate > ventricular rate
• Escape rhythm: narrow QRS (junctional, 40-60 bpm) if block at AV node; wide QRS (ventricular, 20-40 bpm) if infranodal block
• Regular P-P interval and regular R-R interval but independent of each other

• Transcutaneous pacing as bridge in symptomatic patients
• Atropine 0.5-1 mg IV (for junctional escape, often ineffective for infranodal block)
• Dopamine/Epinephrine infusion for hemodynamic compromise
• Permanent pacemaker (PPM) implantation - definitive treatment
• Treat reversible causes (hyperkalemia, Lyme disease, drug toxicity)

6. Hypertrophic Cardiomyopathy (HCM)

• Left ventricular hypertrophy (LVH) voltage criteria: Sokolow-Lyon: S in V1 + R in V5/V6 ≥35 mm
• Deep, narrow Q waves in lateral leads (I, aVL, V5-V6) and inferior leads - "septal Q waves" (pathognomonic)
• Giant negative T-waves in apical HCM (Yamaguchi syndrome) in precordial leads
• Left atrial enlargement (broad, bifid P-wave in II - P mitrale)
• ST depression, T-wave inversions

• Beta-blockers (first-line: Metoprolol, Propranolol) - reduce outflow obstruction
• Verapamil (non-dihydropyridine CCB) - alternative
• Disopyramide - for refractory outflow obstruction
• Septal reduction therapy: alcohol septal ablation or surgical myectomy
• ICD implantation for high risk of sudden cardiac death
• Avoid dehydration, vigorous exercise, vasodilators

7. Ventricular Tachycardia (VT)

• Wide QRS complexes (≥120 ms), rate 100-250 bpm
• Regular rhythm (monomorphic VT) or irregular (polymorphic VT)
• AV dissociation (P-waves independent of QRS - diagnostic)
• Fusion beats and capture beats (pathognomonic)
• Concordance across precordial leads (all positive or all negative)
• Torsades de Pointes: polymorphic VT with rotating axis around baseline, associated with long QT

• Unstable (pulseless VT/VF): Immediate defibrillation (200 J biphasic), CPR, IV Epinephrine, IV Amiodarone 300 mg
• Stable VT: IV Amiodarone (150 mg over 10 min, then infusion), or Lidocaine, or DC cardioversion
• Long-term: ICD (most effective), antiarrhythmic drugs (Amiodarone, Sotalol), catheter ablation
• Correct reversible causes (ischemia, electrolyte disturbance)

8. Acute Pericarditis

• Stage 1: Diffuse concave-up ("saddle-shaped") ST elevation in most leads EXCEPT aVR and V1; PR depression (most specific sign) in same leads; PR elevation in aVR
• Stage 2: ST returns to baseline, T-waves flatten
• Stage 3: T-wave inversions (diffuse)
• Stage 4: ECG normalizes (weeks later)
• No reciprocal changes (distinguishes from STEMI)
• Low-voltage QRS or electrical alternans suggests pericardial effusion

• NSAIDs (Ibuprofen 600 mg TID x 2-4 weeks) - first-line
• Colchicine 0.5 mg BD x 3 months (dramatically reduces recurrence)
• Restrict exercise until symptom-free + CRP normal
• Corticosteroids only for specific indications (connective tissue disease, autoreactive pericarditis)
• Treat underlying cause (viral, bacterial, autoimmune)

9. Wolff-Parkinson-White (WPW) Syndrome

• Short PR interval (<120 ms) - due to bypass tract bypassing AV node delay
• Delta wave - slurred upstroke of QRS (pre-excitation of ventricle via accessory pathway)
• Broad QRS (≥120 ms) - combination of normal + accessory pathway conduction
• Secondary ST-T changes (discordant from delta wave direction)
• Risk: AF with pre-excitation causes extremely rapid ventricular rates (>250 bpm) → VF → sudden death

• Asymptomatic: observation vs. electrophysiology study with risk stratification
• Symptomatic (SVT/AVRT): catheter ablation of accessory pathway (>95% curative - first-line)
• Acute AF with WPW: IV Procainamide or Ibutilide (NOT adenosine, verapamil, digoxin - may accelerate conduction via accessory pathway → VF)
• Avoid AV nodal blocking agents in pre-excited AF

10. Pulmonary Embolism (PE) - Acute Cor Pulmonale

• Sinus tachycardia (most common, present in >40%)
• S1Q3T3 pattern: Deep S-wave in lead I + Q-wave in lead III + T-wave inversion in lead III
• Right heart strain: New RBBB (complete or incomplete), right axis deviation
• T-wave inversions in V1-V4 (right ventricular strain pattern - most common specific finding)
• Right atrial enlargement (P pulmonale - tall peaked P in II >2.5 mm)
• Sinus tachycardia is most sensitive; S1Q3T3 is classic but found in only ~20%

• Massive PE (hemodynamically unstable): Systemic thrombolysis (Alteplase 100 mg IV over 2 hrs), surgical embolectomy, catheter-directed therapy
• Submassive/non-massive: Anticoagulation with LMWH/UFH → DOAC (Rivaroxaban, Apixaban)
• Long-term anticoagulation 3-6 months (provoked) or indefinite (unprovoked/high risk)
• IVC filter if anticoagulation contraindicated
• Oxygen supplementation

Summary Table

Note: The attached ECG shows features consistent with Left Bundle Branch Block (LBBB) + Left Ventricular Hypertrophy as noted by the machine interpretation. In any patient presenting with chest pain, new LBBB must be treated as a STEMI-equivalent and urgent cardiology assessment is required. This interpretation is for educational purposes - clinical correlation with the patient's symptoms, vitals, and troponin levels is essential.