Temporary ventricular pacing now, then referral for a dual-chamber upgrade

Reprogramming the existing device to VVI at 60/min, then referral to the pacing clinic

Telemetry overnight, then an outpatient pacing-clinic check this week

Reprogramming to an atrial rate of 80/min, then reassessment on telemetry

Two episodes of near-fainting today, the second while sitting down

68-year-old man. Two episodes of near-fainting today, the second while sitting down

Single-chamber pacemaker implanted four years ago for sinus node disease. Hypertension on ramipril; also takes aspirin and atorvastatin. No beta blocker, no calcium channel blocker, no digoxin.

Stage 1 of 2

Rasmus Okonkwo walks into triage with his wife, who says he went grey and folded at the knees twice this morning. He is alert now, with no chest pain and no breathlessness. The device pocket looks normal and there is no arm swelling. His pacemaker card is at home. Potassium taken at triage comes back at 4.2 mmol/L.

Tracing 1 of 2 for the quiz “Two episodes of near-fainting today, the second while sitting down”. — Twelve-lead recorded at triage, 25 mm/s, 10 mm/mV. Open this tracing in the studio

Bloods

Potassium (mmol/L): 4.2
Creatinine (umol/L): 96

What does this tracing show?

AAtrial pacing with complete AV block and a junctional escape Your answer
BAtrial pacing with oversensing and inhibited output Your answer
CAtrial pacing with intermittent failure to capture Your answer
DAtrial pacing with second-degree AV block Correct answer Your answer

What else does the tracing show?

AST elevation across the anterior leads Your answer
BQ waves of an old inferior infarct Correct answer Your answer
CVoltage criteria for left ventricular hypertrophy Your answer
DLeft bundle branch block in the conducted beats Your answer

Stage 2 of 2

While he waits he goes grey again sitting on the trolley and comes round within a few seconds. Blood pressure at that moment is 88/54 and his fingers are cold. This monitor strip was running through the episode. The device is a single-chamber system with one lead, in the right atrium.

Tracing 2 of 2 for the quiz “Two episodes of near-fainting today, the second while sitting down”. — Monitor strip recorded during the episode. Open this tracing in the studio

Observations

HR: 30
SpO₂ (%): 96
Respiratory rate: 18
Systolic BP (mmHg): 88
Diastolic BP (mmHg): 54

What happens next?

AReprogramming the existing device to VVI at 60/min, then referral to the pacing clinic Your answer
BTemporary ventricular pacing now, then referral for a dual-chamber upgrade Correct answer Your answer
CTelemetry overnight, then an outpatient pacing-clinic check this week Your answer
DReprogramming to an atrial rate of 80/min, then reassessment on telemetry Your answer

Diagnosis

Second-degree AV block in a patient with an atrial pacemaker

It is important to know exactly what the pacemaker is programmed to do. This patient had a working pacemaker but as it was only atrial pacing, AV block could still occur. The pacemaker needs to be upgraded to a dual system.

Two episodes of near-fainting today, the second while sitting down

The case

On arrival

Bloods

Observations

Diagnosis

Discussion