We present the case of a 79-year-old man with situs inversus totalis who was admitted to the emergency department for syncope caused by high-grade atrioventricular block, with no identifiable reversible causes. Transthoracic echocardiography revealed preserved ejection fraction and no valvular disease.
The chest X-ray showed situs inversus, leading to a thoracic computed tomography scan to confirm the venous anatomy. The computed tomography scan confirmed the complete mirror-image anatomy and excluded venous drainage abnormalities (Figure 1A and B). Despite the unusual anatomy, a dual-chamber pacemaker was successfully implanted in the left prepectoral region via ultrasound-guided axillary vein puncture. Atrial and ventricular leads were positioned in the right atrial appendage and right ventricular apex, respectively (Figure 1E and F), with appropriate electrical parameters.
Dual-chamber pacemaker implantation in a patient with situs inversus totalis with dextrocardia. (A) Axial view and (B) coronal view of thoracic computed tomography scan showing mirror-image anatomy with dextrocardia, normal atrioventricular and ventriculoarterial connections, and right-sided liver. (C) Baseline ECG showing sinus rhythm with right bundle branch block and left posterior fascicular block. (D) ECG performed after syncope revealing trifascicular block with second-degree atrioventricular block Mobitz type II. (E) Posteroanterior and (F) lateral chest radiographs demonstrating left-sided pacemaker generator with transvenous leads directed toward the right atrial appendage and right ventricular apex, confirming successful pacemaker implantation. LA: left atrium; LV: left ventricle; RA: right atrium; RV: right ventricle; PA: pulmonary artery.
This case illustrates the importance of pre-procedural imaging in patients with situs inversus and demonstrates that standard transvenous pacemaker implantation is feasible with careful planning, despite the anatomical inversion.
FundingNone declared.
Conflict of interestNone declared.
