Electrocardiography: how to interpret
A systematic read of the 12-lead ECG with normal values, the patterns examiners show (occlusion MI, hyperkalaemia, pre-excitation, Brugada, LVH), and the traps of lead reversal and Bazett correction.
Tier 2Medical sciences concept
Written with AI assistance and fact-checked against the sources below. For exam study, not clinical decisions. How notes are made
At a glance
- The ECG is cheap, immediate and decisive in acute coronary occlusion, hyperkalaemia, pre-excitation, heart block and inherited arrhythmia syndromes. A normal ECG never excludes coronary disease.
- Read every tracing the same way: calibration, rate, rhythm, axis, intervals, morphology, ST-T, then compare with an old ECG.
- The exam shows a tracing (or describes one) and asks for the diagnosis or the next step. Most marks go to recognising occlusion patterns, electrolyte effects and the dangerous syncope ECGs.
Loading the rest of the note…
Finished reading?
Sources
- Brieger D, Cullen L, Briffa T et al. Comprehensive Australian Clinical Guideline for Diagnosing and Managing Acute Coronary Syndromes 2025. Heart Lung Circ 2025;34(4):309-397AU/NZNational Heart Foundation of Australia and CSANZ, 2025
- Mills NL, Newby LK, Zaman S et al. Fifth Universal Definition of Myocardial Infarction (2026). Eur Heart J 2026ESC/ACC/AHA/WHF, 2026
- Kligfield P, Gettes LS, Bailey JJ et al. Recommendations for the standardization and interpretation of the electrocardiogram, Part I. Circulation 2007;115:1306-24 (with Parts II to VI, 2007 to 2009)AHA/ACCF/HRS, 2007-2009
- Hancock EW, Deal BJ, Mirvis DM et al. Recommendations for the standardization and interpretation of the electrocardiogram, Part V: ST segment, T and U waves, and the QT interval. Circulation 2009;119:e241-50AHA/ACCF/HRS, 2009
- Drezner JA, Sharma S, Baggish A et al. International criteria for electrocardiographic interpretation in athletes: consensus statement. Br J Sports Med 2017;51:704-31British Journal of Sports Medicine, 2017
- Zeppenfeld K, Tfelt-Hansen J, de Riva M et al. 2022 ESC Guidelines for the management of patients with ventricular arrhythmias and the prevention of sudden cardiac death. Eur Heart J 2022;43:3997-4126European Society of Cardiology, 2022
- Last updated
- 14 November 2026
What changed
- 14 November 2026 Personal emails, About story and Australian-style copy