Squiggler

Two episodes of sudden loss of consciousness

The case

76-year-old man. Two episodes of sudden loss of consciousness

Retired carpenter. Hypertension treated with amlodipine. No previous cardiac history. His wife witnessed two brief episodes of syncope today, each lasting about ten seconds, with no warning and no post-ictal confusion. He has fully recovered between episodes.

On arrival

HR
62
Spo2Percent
97
Respiratory rate
16
Temperature (°C)
36.6
Systolic BP (mmHg)
138
Diastolic BP (mmHg)
76

Stage 1 of 1

A 76-year-old man presents to the emergency department after two witnessed syncopal episodes today, each lasting about ten seconds with immediate recovery. His wife describes no seizure activity. He is haemodynamically stable between episodes. A twelve-lead ECG is recorded.

The tracing for the quiz “Two episodes of sudden loss of consciousness”.
Twelve-lead ECG recorded in the emergency department Open this tracing in the studio
The QRS complexes are broad. What is the conduction abnormality responsible for the QRS morphology in V1?
The frontal QRS axis is markedly negative. Which additional conduction structure is blocked?
The PR interval is prolonged at 270 ms. Considering the full conduction picture, what does this pattern most likely explain in a patient presenting with syncope?

Diagnosis

Trifascicular block with syncope from intermittent complete heart block

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

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Discussion

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