Neither; this is left bundle branch block

Dizzy standing up, twice in the last week

Dual-chamber pacemaker four years ago for sinus node disease. Takes doxazosin and indapamide for blood pressure, and amitriptyline at night for neuropathic pain, doubled by her GP a fortnight ago. No blackouts, no chest pain.

Stage 1 of 2

Bridie Kavanagh describes a grey, swimming feeling for a few seconds when she gets out of a chair, worse first thing and after her tablets. She has not fallen. She is sitting comfortably now and this tracing was recorded at rest.

Tracing 1 of 2 for the quiz “Dizzy standing up, twice in the last week”. — Twelve-lead at rest, 25 mm/s, 10 mm/mV. Open this tracing in the studio

What is being paced?

ANeither; this is left bundle branch block Your answer
BThe atrium only Your answer
CThe ventricle only Your answer
DThe atrium and the ventricle Correct answer Your answer

Why are the paced complexes broad, with a dominant negative deflection in V1?

AShe has a left bundle branch block underneath the pacing Your answer
BThe lead paces the right ventricle, so the left ventricle is activated late Correct answer Your answer
CThe lead has been placed in the left ventricle Your answer
DThe broad complexes are ventricular extrasystoles Your answer

Stage 2 of 2

She walks the length of the corridor and back without symptoms, and the tracing is repeated as she sits down. Her blood pressure lying is 132/74 and standing at three minutes 96/58, with the dizziness reproduced.

Tracing 2 of 2 for the quiz “Dizzy standing up, twice in the last week”. — Twelve-lead repeated after walking, 25 mm/s, 10 mm/mV. Open this tracing in the studio

Observations

HR: 96
SpO₂ (%): 98
Respiratory rate: 17
Temperature (°C): 36.5
Systolic BP (mmHg): 132
Diastolic BP (mmHg): 74

What does the second tracing tell you about the device?

AThe leads have become displaced since the first tracing Your answer
BIt is failing to sense Your answer
CIt is failing to capture Your answer
DIt is sensing her own beats and being inhibited by them Correct answer Your answer

What is causing the dizziness?

AA lower rate limit set too low for her Your answer
BIntermittent pacemaker malfunction between tracings Your answer
CA battery approaching the end of its life Your answer
DPostural hypotension from her medication Correct answer Your answer

Dizzy standing up, twice in the last week

The case

On arrival

Observations

Diagnosis

Discussion