Dextrocardia with complete atrioventricular block-the right clinical approach to pace a heart on the right hemithorax: a case report.

Background: A heart positioned on the right side of the thorax can be more a complex situation than it seems, also the potentially associated congenital cardiopathies are variable. In this regard, patients with dextrocardia presenting with complete atrioventricular block require a thorough anatomical investigation to map the veno-arterial system and potential cardiovascular defects before proceeding with a permanent pacing procedure.

Case presentation: A 73-year-old Caucasian woman with no significant medical history presented with syncope. Physical examination showed regular heart sounds with an average heart rate of 35-40 beats per minute and no other relevant physical findings. Chest X-rays revealed a heart positioned in the right hemithorax. A standard electrocardiogram revealed complete atrioventricular block with junctional escape rhythm at nearly 35-40 beats per minute. A transthoracic echocardiogram showed a mirror image dextrocardia without any other remarkable abnormalities. Venogram performed using the left peripheral cephalic vein showed normal venous return into the right atrium positioned on the left side. Surgical intervention consisted of permanent dual chamber pacemaker implantation using the left subclavian vein. Discussion is provided based on the relevant medical literature outlining different potential scenarios with associated cardiac and major vessels abnormalities.

Conclusion: This case highlights an atypical presentation of atrioventricular block in a patient with dextrocardia and situs inversus, for whom a successful dual-pacemaker implantation procedure was performed.