EKG Cheat Sheet
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Sixteen ECG rhythms on real strips, with the rate, rhythm, P wave, PR and QRS of each. Free to use and print, with no sign-up.
ekglab.com/ekg-cheat-sheet.html
Look for: Every P is followed by a QRS, regular, narrow, unremarkable.
A real recording from the PTB-XL database (record 00021), one of the examples in Rhythm Foundations. Definition sources: Kusumoto 2019, Circulation; Samesima 2022, Arq Bras Cardiol; Page 2016, Circulation; Meek 2002a, BMJ.
Look for: Looks like NSR, but the complexes are spread far apart.
A real recording from the PTB-XL database (record 07161), one of the examples in Rhythm Foundations. Definition sources: Kusumoto 2019, Circulation; Da Costa 2002, BMJ.
Look for: Normal morphology, but the beats are crowded together.
A real recording from the PTB-XL database (record 07547), one of the examples in Rhythm Foundations. Definition sources: Page 2016, Circulation; Goodacre 2002, BMJ.
Look for: Sinus P waves with a constant PR, but the rate waxes and wanes.
A real recording from the PTB-XL database (record 00402), coded with sinus arrhythmia by a cardiologist. Definition sources: Samesima 2022, Arq Bras Cardiol; Yasuma 2004, Chest; Singh 2021, Cureus.
Look for: No P waves and no two R-R intervals alike, irregularly irregular.
A real recording from the PTB-XL database (record 04532), one of the examples in Rhythm Foundations. Definition sources: Page 2016, Circulation; Haïssaguerre 1998, N Engl J Med; Goodacre 2002, BMJ; Samesima 2022, Arq Bras Cardiol.
Look for: Look for the sawtooth baseline in II, III, aVF, classic flutter.
A real recording from the PTB-XL database (record 00017), one of the examples in Rhythm Foundations. Definition sources: Page 2016, Circulation; Goodacre 2002, BMJ.
Look for: Fast, regular, narrow, and you can’t find the P waves.
A real recording from the PTB-XL database (record 13186), one of the examples in Rhythm Foundations. Definition sources: Page 2016, Circulation; Mason 2007, Circulation; Esberger 2002, BMJ; Samesima 2022, Arq Bras Cardiol.
Look for: Regular and narrow at 40–60, with no normal upright P before the QRS.
A real recording from the PTB-XL database (record 15689), one of the examples in Rhythm Foundations. Definition sources: Page 2016, Circulation; Ashkanani 2026, Ann Noninvasive Electrocardiol; Samesima 2022, Arq Bras Cardiol.
Look for: Short PR plus a slurred QRS upstroke, the delta wave.
A real recording from the PTB-XL database (record 05303), coded with Wolff-Parkinson-White pattern by a cardiologist. Definition sources: Wolff 1930, Am Heart J; Surawicz 2009, Circulation; Ungaro 2024, J Cardiovasc Dev Dis; Samesima 2022, Arq Bras Cardiol.
Look for: Every P conducts, but the PR is long and constant.
A real recording from the PTB-XL database (record 09619), one of the examples in Rhythm Foundations. Definition sources: Kusumoto 2019, Circulation; Samesima 2022, Arq Bras Cardiol.
Look for: A P with no QRS after it, Mobitz I lengthens the PR first; Mobitz II drops suddenly.
A real recording from the PTB-XL database (record 01222), one of the examples in Rhythm Foundations. Definition sources: Kusumoto 2019, Circulation; Denes 1975, Am Heart J; Barold 2024, Front Cardiovasc Med; Samesima 2022, Arq Bras Cardiol.
Look for: P waves and QRS each march to their own beat, no fixed PR.
A real recording from the PTB-XL database (record 00959), one of the examples in Rhythm Foundations. Definition sources: Kusumoto 2019, Circulation; Ashkanani 2026, Ann Noninvasive Electrocardiol; Samesima 2022, Arq Bras Cardiol.
Look for: Wide, fast, regular and monomorphic, look for AV dissociation and capture/fusion beats.
A real recording from the MIT-BIH Malignant Ventricular Ectopy Database (record 605), within an episode its annotators marked as ventricular tachycardia. Definition sources: Al-Khatib 2018, J Am Coll Cardiol; Page 2016, Circulation; Samesima 2022, Arq Bras Cardiol; Alzand 2011, Europace.
Look for: A repeating two-beat pattern, every other complex is wide, early, and P-less.
A real recording from the PTB-XL database (record 04637), coded with a bigeminal pattern of premature ventricular complexes by a cardiologist. Definition sources: Koester 2020, Cureus.
Look for: A repeating three-beat pattern, two normal, then a wide PVC.
A real recording from the PTB-XL database (record 15535), coded with a trigeminal pattern of premature ventricular complexes by a cardiologist. Definition sources: Koester 2020, Cureus.
Look for: Sharp vertical pacing spikes precede the complexes; V-pacing gives a wide LBBB-like QRS.
A real recording from the PTB-XL database (record 00144), coded with a paced rhythm by a cardiologist. Definition sources: Tan 2026; Safavi-Naeini 2016, Tex Heart Inst J; Samesima 2022, Arq Bras Cardiol.
Look for: No discernible QRS, ST, or T, just disorganised, varying-amplitude waveform.
Definition sources: Al-Khatib 2018, J Am Coll Cardiol; Samesima 2022, Arq Bras Cardiol.
Look for: A flat or near-flat line, confirm in more than one lead and exclude fine VF.
Definition sources: Neumar 2010, Circulation; Ewy 1984, Ann Emerg Med; Ornato 1987, Crit Care Med.
The cheat sheet shows you the patterns. Practice is what makes them stick.
Yes. They are two names for the same test, the electrocardiogram. EKG comes from the German spelling and is common in the United States; ECG is used in most other countries. EKGLab uses both.
Yes. Each strip is a 10-second recording from a published ECG database, shown at 25 mm/s and 10 mm/mV, the same strips as the EKG Dictionary. Each one names its record.
Yes. Use the Print button at the top of the page. In the print window you can also save it as a PDF.
Ask the same six questions of every strip, in order: is it regular, what is the rate, what about the P waves, what is the PR interval, is the QRS narrow or wide, and then name the rhythm.
No. It is for learning to read EKGs. It describes what each rhythm looks like on the strip and is not clinical advice.