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( B) Lateral chest X-ray showing correct lead and device positions. ( A) Post-procedural postero-anterior chest X-ray excluding pneumothorax/haemothorax. Sequential AV pacing was successful ( Figure 2A). The atrial sensing setup feature was run determining an A4 threshold of 1.0 m/s 2, A3 threshold of 3.7 m/s 2, A3 window end of 860 ms, and a sensing vector of 1 + 3. 5 A mid-septal location was chosen on this occasion.
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Right femoral venous access was obtained and a Micra AV™ (Medtronic Plc, USA) was implanted using the well-described implantation technique. The device was placed in a TYRX™ envelope (Medtronic Plc, USA) and the wound was closed in two layers. The RA lead was tested then connected to an Accolade SR (Boston Scientific, Massachusetts, USA) device. The RV lead was extracted using a 9 Fr Evolution ® RL sheath (Cook Medical, USA). Dissection was made to the pacemaker generator and it was liberated from the pre-pectoral pocket. A left infra-clavicular horizontal incision was made through the old scar using a PlasmaBlade™ (Medtronic Plc, USA). A temporary pacing wire was placed through left femoral venous access. This was performed under general anaesthesia with prophylactic antibiotic cover.
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The patient was admitted electively for the procedure. Transvenous RV lead extraction with leadless pacemaker implantation was chosen as the first-line strategy, with a view to subsequent TV surgery (either via sternotomy or minimally invasive surgery) if severe TR persisted despite extraction of the RV lead. Her estimated risk of inpatient surgical mortality for TV replacement or repair was 4.1% (EUROSCORE II). The patient’s case was discussed in our cardiology/cardiothoracic multi-disciplinary team meeting. ( B) Modified apical four-chamber view suggesting right ventricular lead impingement of the tricuspid valve septal leaflet. ( A) Apical four-chamber view showing severe tricuspid regurgitation. Left ventricular systolic function was normal, and there were no other significant valvular abnormalities. The RV was non-dilated with preserved systolic function. Transthoracic echocardiography (TTE) revealed severe TR due to apparent tethering of the septal leaflet of the TV by the RV lead ( Figure 1A and B, Video 1A and B). despite the use of an algorithm to minimize ventricular pacing (AAI-DDD mode).Ĭlinical examination revealed peripheral oedema and an elevated jugular venous pressure with prominent V waves. Pacemaker interrogation revealed that the patient was 100% atrially paced and had developed AV conduction disease with a 10% ventricular pacing requirement at a base rate of 60 b.p.m. An echocardiogram performed prior to her initial pacemaker implant was normal apart for minor aortic valve sclerosis. This was a Medtronic™ Versa ® dual-chamber pacemaker with active fixation Medtronic™ 55 leads to the RA appendage and RV apex, respectively. She had a history of hypertension, type II diabetes mellitus, hypothyroidism, previous excision of a benign left atrial myxoma, previous ablation for typical atrial flutter, and dual-chamber pacemaker implantation for sinus node dysfunction 14 years ago. TimelineĪ 66-year-old woman presented with a year-long history of exertional dyspnoea, peripheral oedema, and postural neck pulsations. We describe a novel approach to maintaining atrioventricular (AV) sequential pacing in a patient with sinus node dysfunction, AV conduction disease, and severe lead-related TR. Placement of pacing leads across the TV is generally avoided in such circumstances. Multiple approaches to pacemaker implantation after transvenous lead extraction (TLE) or surgical TV repair have been described. 1–3 The development of significant lead-related TR is associated with right ventricular (RV) and atrial (RA) dilatation, an increased risk of heart failure hospitalization and all-cause mortality. This develops through a number of mechanisms including the failure of leaflet coaptation or direct damage to the TV or to its sub-valvular apparatus and can result in significant tricuspid regurgitation (TR). The use of transvenous pacing leads is associated with the risk of developing tricuspid valve (TV) dysfunction. The Micra™ AV is a second-generation leadless pacemaker which uses a three-axis accelerometer to sense the atrial mechanical contraction, thus enabling atrioventricular synchronous pacing.Ītrio-ventricular sequential pacing can be achieved using a dual-pacemaker approach involving the use of a Micra™ AV and a transvenous AAI. Lead-related tricuspid valve dysfunction is an important and increasingly recognized complication.