A thumping in the chest when he lies down at night, going on for months

2026-09-12

The case

24-year-old man. A thumping in the chest when he lies down at night, going on for months

Fit, plays football twice a week and has never had symptoms while running. No blackouts. No family history of sudden death. Takes nothing; drinks little coffee.

On arrival

HR: 74
SpO₂ (%): 99
Respiratory rate: 14
Temperature (°C): 36.7
Systolic BP (mmHg): 124
Diastolic BP (mmHg): 76

Stage 1 of 1

He is well, with a normal cardiovascular examination and no murmur. A medical student is with you on the ward round and has never seen a tracing like this one.

The tracing for the quiz “A thumping in the chest when he lies down at night, going on for months”. — Twelve-lead, 25 mm/s, 10 mm/mV. Open this tracing in the studio

What does this tracing show?

ASinus bradycardia with ventricular escape beats Your answer
BSinus rhythm with atrial bigeminy Your answer
CSinus rhythm with ventricular bigeminy Correct answer Your answer
DNon-sustained ventricular tachycardia Your answer

The student asks where the ectopic beats are coming from. Which answer does this tracing support?

AThe atria — each ectopic beat is preceded by an early, abnormal P wave Your answer
BThe left ventricle — the ectopic QRS is dominantly positive in V1 Your answer
CThe AV junction — the ectopic QRS is narrow and identical to the sinus beats Your answer
DThe right ventricle — the ectopic QRS is dominantly negative in V1 Correct answer Your answer

Diagnosis

Ventricular bigeminy from a right ventricular focus

The morphology of ventricular extrasystoles can sometimes reveal the ectopic focus. In this case it is an atypical LBBB pattern indicating a right ventricular focus.

Clinically it can be relevant in locating potential targets for ablative measures and a diagnostic puzzle piece in structural heart disease.

Embed

<script async src="https://www.squiggler.io/embed.js" data-case="a-thumping-in-the-chest-when-he-lies-down-at-night-going-on-for-months"></script>

Or, where scripts are stripped:

<iframe src="https://www.squiggler.io/blog/a-thumping-in-the-chest-when-he-lies-down-at-night-going-on-for-months/embed" title="A thumping in the chest when he lies down at night, going on for months — ECG case from Squiggler" width="100%" height="900" style="border:0" loading="lazy"></iframe>

This tracing was generated, not recorded. It opens in the studio with every dial live.

Open the studio

Discussion

Comments are read before they appear. Disagreement about a reading is welcome — this is a teaching column and the arguments are the useful part. No account, no email.