Collapsed at the kitchen sink with no warning, out for a few seconds

2026-09-11

The case

77-year-old woman. Collapsed at the kitchen sink with no warning, out for a few seconds

Paroxysmal atrial fibrillation on apixaban. Treated hypertension. Bisoprolol increased from 2.5 mg to 5 mg three weeks ago for palpitations. Two similar collapses in the past month, both unwitnessed.

On arrival

HR: 46
SpO₂ (%): 97
Respiratory rate: 16
Temperature (°C): 36.4
Systolic BP (mmHg): 122
Diastolic BP (mmHg): 70

Stage 1 of 2

She is alert, warm and dry, with no injuries from the fall and no tongue biting or incontinence. Heart sounds are normal and there is no murmur. On the monitor she goes pale mid-sentence, is unresponsive for a few seconds, then comes round on her own with no intervention. This is the strip across that moment.

The tracing for the quiz “Collapsed at the kitchen sink with no warning, out for a few seconds”. — Monitor strip, lead II, 25 mm/s, 10 mm/mV. Open this tracing in the studio

What does this strip show?

AElectrode contact lost and regained across the flat segment Your answer
BAsystolic cardiac arrest with spontaneous return of circulation Your answer
CAtrial fibrillation ending in a long pause before sinus rhythm resumes Correct answer Your answer
DComplete heart block with a slow ventricular escape rhythm Your answer

The strip opens with an irregularly irregular rhythm with no discernible P waves, consistent with atrial fibrillation, which then stops abruptly. A prolonged flat segment follows before narrow QRS complexes resume at a slow rate. This is a conversion pause, not lead disconnection, because the baseline remains clean through the pause and QRS morphology is unchanged on either side. Complete heart block would show a continuing atrial rhythm with a regular slow escape, which is not the pattern here.

Stage 2 of 2

She is back to herself and remembers none of it. Potassium 4.2, magnesium 0.85, TSH normal, creatinine 84, troponin not raised. She has been anticoagulated for three years and has never missed a dose. She asks whether she can go home, and whether the tablets are to blame.

Bloods

TSH (m IU/L): 2.1
Magnesium (mmol/L): 0.85
Potassium (mmol/L): 4.2
Creatinine (umol/L): 84

What does the strip commit you to?

ARefer for tilt-table testing to confirm vasovagal syncope Your answer
BReduce the beta blocker and have a informed discussion with the patient about the pros and cons of implanting a pacemaker Correct answer Your answer
CDischarge on a halved bisoprolol dose with an outpatient 24-hour tape Your answer
DHold the apixaban until the pauses have been brought under control Your answer

The strip documents a symptomatic asystolic conversion pause in a patient on a beta blocker recently uptitrated, so reducing the bisoprolol is essential. However, the pause itself and the recurrent collapses point to sinus node disease, and drug withdrawal alone may not prevent further episodes. A pacemaker discussion is warranted during this admission because the strip has already captured the mechanism of her syncope. Discharging with only a Holter risks a fall with injury while waiting for a recording that may not capture the next event, and stopping anticoagulation would increase stroke risk from her known paroxysmal atrial fibrillation.

Diagnosis

Tachy-brady sick sinus syndrome: an asystolic conversion pause on termination of atrial fibrillation

This strip captures a conversion pause: atrial fibrillation terminates and the sinus node, suppressed by the preceding tachycardia, takes several seconds to recover. The pause is long enough to cause syncope. The recent increase in bisoprolol is a likely contributor, both to the sinus suppression and to the slow rate on recovery, so reducing or stopping it is the first step.

A witnessed asystolic pause of this length with syncope is an indication for pacemaker implantation, and the discussion should happen during this admission. A Holter alone risks missing infrequent pauses, and the strip already shows what it would be looking for.

References

Brignole M, Moya A, de Lange FJ, et al. 2018 ESC Guidelines for the diagnosis and management of syncope. Eur Heart J. 2018;39(21):1883-1948.
Kusumoto FM, Schoenfeld MH, Barrett C, et al. 2018 ACC/AHA/HRS Guideline on the Evaluation and Management of Patients With Bradycardia and Cardiac Conduction Delay. J Am Coll Cardiol. 2019;74(7):e51-e156.

Embed

<script async src="https://www.squiggler.io/embed.js" data-case="collapsed-at-the-kitchen-sink-with-no-warning-out-for-a-few-seconds"></script>

Or, where scripts are stripped:

<iframe src="https://www.squiggler.io/blog/collapsed-at-the-kitchen-sink-with-no-warning-out-for-a-few-seconds/embed" title="Collapsed at the kitchen sink with no warning, out for a few seconds — 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.