Presyncope, and a pulse of about thirty
The tracing
A 78-year-old woman is brought in after two episodes of feeling about to faint, both while standing at the kitchen sink. She did not lose consciousness and did not fall. She takes amlodipine and nothing else; no beta blocker, no rate-limiting calcium channel blocker, no digoxin.
She is alert and cool peripherally. Blood pressure 104/58, pulse felt at the wrist about thirty and regular. Chest is clear. Bloods, including potassium, are unremarkable.
What is going on here?
Answer
Show the answer and explanation
Complete (third-degree) atrioventricular block with a broad ventricular escape.
- The atrial rate is about 94 and regular.
- The ventricular rate is about 33 and regular.
- The two rates are unrelated. No PR interval repeats, and there is no P at any consistent distance in front of any QRS.
- The escape complexes are broad.
This tracing was generated, not recorded. It opens in the studio with every dial live.
Discussion
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