571 SUCCESSFUL PERMANENT PACEMAKER IMPLANTATION IN A PATIENT WITH DEXTROCARDIA AND SITUS INVERSUS TOTALIS: LOOKING AT THE MIRROR.

Abstract

Abstract Background Dextrocardia is a rare congenital condition with a prevalence of 0.83 per 10000 pregnancies. Its most common configuration is situs inversus totalis, also known as “mirror-image dextrocardia”. This case report presents a clinical case of symptomatic sinus node dysfunction requiring permanent pacemaker implantation (PPI) in a patient with mirror-image dextrocardia. Case summary A 81-year-old female patient with known situs inversus totalis presented with recurrent syncope. Sick sinus syndrome was diagnosed after documentation of critical pauses (>6.3”) at 24-hour Holter monitoring, giving indication to elective PPI. At admission, 12-lead ECG showed sinus bradycardia and right axis deviation on the frontal plane (standard peripheral leads position and precordial leads on the right side of the chest). Transthoracic echocardiography was performed prior to the procedure with the ultrasound probe flipped and placed on the patient's right side of the thorax, thus achieving standard echocardiography windows and images. A preserved biventricular systolic function and the absence of relevant valvular disease or cardiac malformations was documented. The next day, a dual-chamber pacemaker was implanted following standard technique with the operator standing on the right side of the patient and with right subclavian vein puncture; the pacemaker pocket was created in the right pectoral region. The entire procedure was performed under fluoroscopic guidance using horizontally 180° flipped views, therefore obtaining identical images to those of standard PPI procedures, helping the operator identify anatomical structures during lead positioning. [Fig. 1 a - b] Chest X-ray confirmed correct pacemaker lead placement and absence of procedure-related complications. Stable and satisfactory lead parameters were observed at follow-up. Discussion In literature there are only a few case reports on PPI in situs inversus totalis. The symmetrical disposition of the anatomy makes transvenous PPI technically demanding. In this case the challenge was overcome by using flipped fluoroscopy images, to facilitate lead positioning maneuvres. This technique can be considered only in situs inversus totalis and not in other forms of dextrocardia, such as dextroversion and destroposition, because it is the only situation in which the anatomy is the mirror image of the normal one.