A 62-year-old man presented with palpitations. An ECG showed sinus rhythm at 83 beats per minute with premature atrial complexes occurring in a pattern of trigeminy. The QRS complexes were normal in axis and duration without signs of right or left ventricular hypertrophy. There were no abnormalities in the ST segment or T waves. The final diagnosis was sinus rhythm with atrial premature complexes in a pattern of trigeminy and an otherwise normal ECG.

1. Stepwise interpretation of ECG
ID 352

2. ID 352 –62 year old man with palpitation

3. ID 352 –62 year old man with palpitation
Can you see P waves?

4. Yes – There is sinus rhythm with premature atrial complexes (the P waves marked by an arrow)
Every 3rd
P is premature (trigeminy) - The sinus P waves show no evidence of right or left atrial enlargement
ID 352 - Sinus rhythm, 83/ min., with atrial premature complexes in a pattern of trigeminy

5. ID 352 – Sinus rhythm, 83/ min., with atrial premature complexes in a pattern of trigeminy
Let’s now look at the QRS complexes: There is normal QRS axis (between 0 and 90 degrees)

6. The QRS duration is normal : There is no right bundle branch block, left bundle branch block or non-specific block
ID 352 - Sinus rhythm, 83/ min., with atrial premature complexes in a pattern of trigeminy

7. ID 352 - Sinus rhythm, 83/ min., with atrial premature complexes in a pattern of trigeminy
There is no right ventricular hypertrophy or left ventricular hypertrophy

8. - Sinus rhythm, 83/ min., with atrial premature complexes in a pattern of trigeminy
There are no QRS signs of myocardial infarction –There are normal ST segment and normal T waves

9. ID 352 - Final diagnosis:
Sinus rhythm, 83/ min., with atrial premature complexes in a pattern of trigeminy
Otherwise, a normal ECG

10. ID 352 - Final diagnosis:
Sinus rhythm, 83/ min., with atrial premature complexes in a pattern of trigeminy
Otherwise, a normal ECG