ECG Analysis

Machine-Reported Parameters (from the printout)

Machine Diagnosis (as printed on the ECG)

• Sinus Rhythm
• Acute Inferior Myocardial Infarction?
• Occlusion of the Right Coronary Artery (RCA)
• Slight ST Elevation (II, III, aVF)
• ST Depression (V2, V3)
• Inverted T Waves (V3)
• Slight ST Elevation (II, III, aVF)
• Prolonged QT Interval
• Report Confirmed by: DR. SELF

ECG Interpretation

Rhythm

ST Changes - Inferior Leads (II, III, aVF)

• ST elevation in leads II, III, and aVF - the hallmark of an inferior STEMI.
• Notably, ST elevation appears greater in lead III than in lead II, which is a 90% sensitive and 71% specific marker for right coronary artery (RCA) occlusion (vs. left circumflex). This is consistent with the machine's RCA diagnosis.

Reciprocal Changes

• ST depression in leads I and aVL - the expected reciprocal mirror image of inferior ST elevation. This increases specificity and is associated with larger infarct size and higher mortality.
• ST depression in V2-V3 - this can reflect:
  1. Reciprocal change from the inferior MI
  2. Posterior wall extension (posterior MI accompanying inferior MI)
  3. Simultaneous anterior ischemia

Right Ventricular Involvement

• ST elevation that is greater in lead III than lead II, combined with ST elevation in lead aVF and possible ST elevation in V1, raises concern for concomitant right ventricular (RV) infarction. This is a critical finding because:
  • RV infarction complicates ~30-50% of inferior STEMIs due to RCA occlusion
  • These patients are preload-dependent - nitrates are relatively contraindicated and fluid resuscitation is often needed
  • Right-sided ECG leads (V3R-V4R) should be urgently recorded

T Wave Changes

• Inverted T waves in V3 as noted by the machine - consistent with ischemic T wave changes in the anteroseptal distribution.

QT Interval

• Prolonged QTc (~471 ms) - warrants monitoring for ventricular arrhythmias, especially given the ischemic substrate.

Localization Summary

Clinical Priorities (Acute Management)

1. Immediate reperfusion - Primary PCI (percutaneous coronary intervention) is the treatment of choice if door-to-balloon time <120 min; fibrinolysis if PCI not available within that window.
2. Right-sided leads (V3R, V4R) - must be recorded immediately to confirm/exclude RV infarction. ST elevation ≥1 mm in V4R is diagnostic.
3. Avoid nitrates if RV infarction confirmed - can precipitate severe hypotension due to preload dependence.
4. Avoid excess diuresis - same reason.
5. IV fluids (cautious bolus) if hypotensive with RV MI.
6. Antiplatelet therapy - aspirin + P2Y12 inhibitor (ticagrelor or clopidogrel).
7. Anticoagulation - heparin (UFH or LMWH per protocol).
8. Continuous cardiac monitoring - risk of complete AV block (RCA supplies AV node in ~90% of people), bradyarrhythmias, or VF.

Key Teaching Points (from Rosen's Emergency Medicine)

"ST segment elevation inferiorly that is greater in lead III than in lead II, accompanied by ST segment depression in leads aVL, I, or both, is 90% sensitive and 71% specific for RCA occlusion."

"ST segment elevation in lead V1 in the presence of an inferior MI (with elevation greater in III than II) suggests concomitant right ventricular infarction."

"Coexistent reciprocal change with inferior STEMI is associated with larger infarct size and increased mortality."

• Rosen's Emergency Medicine, Anatomic Location of AMI section

⚠️ Disclaimer: This analysis is for educational purposes. All clinical decisions must be made by a licensed physician with direct patient assessment.

ECG Analysis

Recorded Parameters (from the printout header)

Rhythm Analysis

Lead-by-Lead Morphology

Limb Leads (I, II, III, aVR, aVL, aVF)

• Lead I: Low amplitude, relatively flat - suggests the cardiac axis may be vertical or rightward. QRS appears narrow.
• Lead II: Small upright complexes visible; ST segment appears near-isoelectric.
• Lead III: Similar pattern to II with modest deflections.
• aVR: Predominantly negative deflection (normal).
• aVL: Small, somewhat biphasic or negative complexes.
• aVF: Small upright complexes.

Precordial Leads (V1-V6)

• V1: Small r wave followed by deep S; appears to have a prominent negative component - consistent with normal right precordial morphology.
• V2: Transition zone area; appears to have a biphasic or rS pattern.
• V3: The QRS becomes more prominent. There appear to be tall, peaked, broad T waves visible in V3-V5 - raising concern for hyperacute T waves of early ischemia/STEMI equivalent.
• V4: Notably tall, broad T waves - the most striking finding on this ECG. The T wave amplitude in V4 appears disproportionately large relative to the QRS complex. This is a classic hyperacute T wave pattern.
• V5: Large QRS with prominent upright T; likely a transitional pattern.
• V6: Smaller complexes; T wave upright.

Key Findings & Interpretation

1. Hyperacute T Waves in V3-V5 (Most Significant Finding)

From Rosen's Emergency Medicine: "Note the broad, tall T waves in leads V3 and V4 in this patient with chest pain and diaphoresis. These are the hyperacute T waves of early ST segment elevation myocardial infarction."

2. Markedly Prolonged QTc (~550 ms)

• Torsades de Pointes (polymorphic VT)
• Ventricular fibrillation
• Sudden cardiac death

3. Low Limb Lead Voltage (possible)

• Acute myocarditis
• Pericarditis with effusion
• Early anterior STEMI with volume-related low voltage

4. Borderline Sinus Bradycardia (59 bpm)

Differential Diagnosis

Localization

Clinical Priorities

1. Immediate serial ECGs (every 5-10 min) - hyperacute T waves may progress to ST elevation within minutes.
2. Cardiac biomarkers - high-sensitivity troponin I/T (serial at 0 and 1-2 hours).
3. Right-sided leads to exclude RV involvement.
4. Posterior leads (V7-V9) to exclude posterior extension.
5. Electrolytes stat - K+, Mg2+, Ca2+ to address QT prolongation.
6. Review medications for QT-prolonging drugs.
7. Aspirin + anticoagulation if ACS confirmed.
8. Cath lab activation if ST elevation develops or clinical picture is consistent with STEMI.
9. Avoid QT-prolonging drugs given QTc of 550 ms.
10. Continuous cardiac monitoring given VT/VF risk from prolonged QTc + ischemia.

⚠️ Disclaimer: This is an educational analysis only. All clinical decisions must be made by a licensed physician with direct patient assessment. Image quality and angle limit certainty of measurements.