Racing heart walking up the hill

Ruth has had two days of palpitations and breathlessness on exertion. She grew up in Kerala and was told she had rheumatic fever as a child; a doctor once mentioned a murmur, but she has never had it investigated. She takes no regular medicines.

Stage 1 of 3

The GP sends a phone photograph of the ECG taken in the surgery.

Tracing 1 of 2 for the quiz “Racing heart walking up the hill”. — 12-lead, 25 mm/s, 10 mm/mV Open this tracing in the studio

What is the rhythm?

AAtrial fibrillation with fast ventricular response Correct answer Your answer
BAtrial flutter with variable block Your answer
CMultifocal atrial tachycardia Your answer
DSinus tachycardia with frequent atrial ectopics Your answer

The rhythm is irregularly irregular with no identifiable P waves and a fine fibrillatory baseline, which is atrial fibrillation. The ventricular rate is approximately 128 per minute. Atrial flutter would show regular sawtooth atrial activity, most often with a regular or group-patterned ventricular response. Multifocal atrial tachycardia requires at least three distinct P wave morphologies, and there are no discrete P waves here at all.

Stage 2 of 3

You pull up a twelve-lead from two years ago, scanned from the electronic record. It was done as a pre-operative assessment for cataract surgery.

Tracing 2 of 2 for the quiz “Racing heart walking up the hill”. — 12-lead, 25 mm/s, 10 mm/mV Open this tracing in the studio

What does the old tracing show that changes how today's ECG is read?

ALeft atrial enlargement Correct answer Your answer
BFirst-degree atrioventricular block Your answer
CRight atrial enlargement Your answer
DA normal ECG Your answer

The P waves in lead II are broad and notched, giving the classic bifid or M-shaped morphology of P mitrale. In V1 the P wave is biphasic with a negative terminal portion. Together these indicate left atrial enlargement. The PR interval is approximately 170 ms, which is within normal limits, so first-degree block is not present. Right atrial enlargement (P pulmonale) would produce tall, peaked P waves, not broad notched ones.

Stage 3 of 3

On auscultation you hear a low-pitched mid-diastolic rumble at the apex with an opening snap. A bedside echocardiogram confirms rheumatic mitral stenosis with a valve area of 1.1 cm squared and a dilated left atrium.

What is the most appropriate form of anticoagulation?

AVitamin K antagonist (warfarin) Correct answer Your answer
BNo anticoagulation; CHA2DS2-VASc is only 1 Your answer
CA direct oral anticoagulant such as apixaban Your answer
DAspirin Your answer

Atrial fibrillation in the setting of moderate-to-severe rheumatic mitral stenosis requires anticoagulation with a vitamin K antagonist regardless of the CHA2DS2-VASc score. The score was not validated in valvular AF of this kind and does not apply. Direct oral anticoagulants are not recommended: the INVICTUS trial demonstrated that rivaroxaban was inferior to a VKA in patients with rheumatic heart disease-associated AF. Aspirin does not provide adequate stroke prevention in AF.

Diagnosis

Atrial fibrillation with severe rheumatic mitral stenosis

The first tracing shows atrial fibrillation with a fast ventricular response. The irregularly irregular rhythm and absent P waves distinguish it from flutter, which would produce regular sawtooth atrial activity and a patterned ventricular rate. Multifocal atrial tachycardia would show at least three distinct P wave morphologies, and these are absent here.

The second tracing, recorded two years earlier, holds the clue to the cause. The broad, notched P waves in lead II and the biphasic P wave in V1 with a negative terminal deflection are the signature of left atrial enlargement. In a woman with childhood rheumatic fever, left atrial enlargement on ECG points directly at the mitral valve, and the echocardiographic finding of severe mitral stenosis confirms the diagnosis. Anticoagulation in AF associated with moderate-to-severe rheumatic mitral stenosis requires a vitamin K antagonist. The CHA2DS2-VASc score was not validated in valvular AF of this kind, and the INVICTUS trial showed that rivaroxaban was inferior to a VKA in rheumatic heart disease-associated AF.

References

Connolly SJ, Karthikeyan G, Ntsekhe M, et al. Rivaroxaban in Rheumatic Heart Disease-Associated Atrial Fibrillation. N Engl J Med. 2022;387(11):978-988.
Van Gelder IC, Rienstra M, Bunting KV, et al. 2024 ESC Guidelines for the management of atrial fibrillation. Eur Heart J. 2024;45(36):3314-3414.

Racing heart walking up the hill

The case

On arrival

Diagnosis

References

Discussion