ECG Analysis

Technical Details

• Date/Time: 1-Jan-2011, 00:02:39
• Paper speed: 25 mm/s | Gain: 10 mm/mV
• Filter: 0.05-40 Hz, 50 Hz notch
• Leads shown: I, II, III, aVR, aVL, aVF, V1-V6

Measured Intervals (from machine printout)

Machine Interpretation (printed on ECG)

1. Sinus rhythm with sinus arrhythmia
2. Low voltage in extremity leads (QRS deflection < 0.5 mV in limb leads)
3. Abnormal ECG
4. Anteroseptal myocardial infarction (40+ ms Q wave in V1-V4), of indeterminate age

Detailed Lead-by-Lead Analysis

Rhythm

• Sinus rhythm with sinus arrhythmia - P waves are present before each QRS, upright in leads I and II, inverted in aVR (normal sinus axis). The RR interval variability reflects sinus arrhythmia, which is physiologically normal (often breath-related).
• Rate: 98 BPM - upper-normal, near the tachycardic threshold.

P Waves

• Present and consistent morphology - normal sinus origin confirmed.
• PR interval 136 ms - normal.

QRS Complex

• Duration 85 ms - narrow, no bundle branch block.
• Low voltage in limb leads - QRS amplitude < 0.5 mV (5 mm) in all limb leads (I, II, III, aVL, aVF). This is a significant finding.
• Poor R-wave progression in V1-V4 - the machine reports Q waves ≥40 ms in V1-V4, consistent with the anterior/anteroseptal infarct pattern. On the tracing, R waves are diminutive or absent in the precordial leads V1 to V4.

ST Segments and T Waves

• Visual assessment from the tracing shows relatively flat/isoelectric ST segments without gross elevation or depression, but subtle changes may be present in the precordial leads given the poor R-wave progression.

QT Interval

• QTc 416 ms (Bazett) / QTcF 425 ms (Fridericia) - both within normal limits.

Key Findings Summary

Clinical Interpretation

1. Anteroseptal infarction pattern (V1-V4): The Q waves in V1-V4 strongly suggest a prior anterior MI - likely involving the LAD (left anterior descending artery) territory. The word "indeterminate age" means the machine cannot distinguish between a remote scar and a subacute infarction. Correlation with serial ECGs, troponin levels, and clinical history is mandatory.
2. Low limb lead voltage: This must be explained. The differential includes:
   • Pericardial effusion (most important to rule out - can progress to tamponade)
   • Emphysema / COPD (air trapping increases distance between heart and electrodes)
   • Obesity
   • Hypothyroidism (commonly associated with both low voltage and pericardial effusion)
   • Infiltrative cardiomyopathy (amyloidosis, sarcoidosis)
   • Anasarca / severe peripheral edema

Recommended Next Steps

• Echocardiogram - to assess for pericardial effusion, wall motion abnormalities (anterior hypokinesis/akinesis from prior MI), and LV function
• Serial troponins - to rule out active ischemia/NSTEMI
• Compare with prior ECGs if available
• Thyroid function tests (TSH) - hypothyroidism can cause both low voltage and pericardial effusion
• Chest X-ray - assess heart size, pulmonary edema, lung hyperinflation
• Cardiology review - this ECG warrants urgent specialist assessment given the infarct pattern

Important note: This ECG analysis is provided for educational purposes. Clinical decisions must be made by a qualified physician who can integrate this with the patient's symptoms, history, examination, and other investigations.