Acute Thrombosis During Atrial Leadless Pacemaker Implantation.

BACKGROUND

Atrial leadless pacemakers (LPs) provide physiological pacing, but they still carry procedural risks.

CASE SUMMARY: We report the case of an elderly immobilized patient with sinus node dysfunction but without atrioventricular conduction block, who underwent atrial LP implantation (Aveir AR). The patient had an angulated inferior vena cava and poor cooperation during surgery, which resulted in a significantly prolonged procedure. During the operation, an acute thrombus formed in the delivery catheter, manifesting as high impedance for the LP. The thrombus was removed with forceps and heparinized saline flushing, allowing the LP to be implanted successfully without complications.

DISCUSSION: Acute thrombosis during atrial LP implantation is rare but may occur in hypercoagulable states or with prolonged procedures. High impedance during mapping can be an early sign. Careful preoperative risk assessment and individualized heparinization, preferably guided by activated clotting time, may help prevent this complication. If thrombus forms, prompt retrieval, gentle extraction, and heparinized flushing can preserve delivery system integrity.

TAKE-HOME MESSAGES: Aveir AR atrial LP implantation can be complicated by acute thrombosis, particularly in hypercoagulable state and prolonged procedural time. Acute thrombus formation may manifest as abnormally high impedance during LP mapping.