1002 A HEART BEYOND A MIRROR: WHEN CCTGA ENCOUNTERS SITUS VISCERUM INVERSUS
Authors: Rispoli Antonella , Nocilla Alessandra , Alfano Antonia , Nigro Emanuele , Mucciolo Carlo , Benvenga Rossella Maria , Rodolfo Citro , Vecchione Carmine , Ciccarelli Michele , Galasso Gennaro 
Published: December 2022

Abstract

Background
Congenitally corrected transposition of great arteries (ccTGA) is an uncommon complex congenital heart disease with atrio-ventricular and ventriculo-arterial connections discondance. ccTGA may be associated with a situs solitus or situs inversus (34% of cases). Situs inversus is a mirror image of normal with the systemic ventricle situated on the right side. Instead, dextrocardia represents 20% of cases.

Case clinic and discussion
Came to our observation a 61 years old female, symptomatic for dyspnea on exertion (NYHA II). She had no past medical history of cardiovascular events. In anamnesis two full-term pregnancies without complications. Transthoracic echocardiogram found atrioventricular and ventriculo-arterial discordance in absence of significant valvulopathy. Cardiac computed tomography showed pulmonary veins linked to right atrium, superior and inferior cava veins connected to the left atrium; right atrium with tricuspid valve was connected to a morphologically left ventricle and left atrium with mitral valve was linked to morphologically right ventricle; pulmonary artery was connected to morphologically left ventricle instead aorta with aortic valve was linked to morphologically right ventricle. Cardiac MRI confirmed cctga in situs viscerum inversus, mild subpulmonary stenosis, moderate dilatation of arterial pulmonary trunk, and also intramyocardial late gadolinium enhancement due to fibrosis involving anterior and inferior interventricular junctions. Cardiac Holter monitoring showed sinus rhythm with some brief phases of low atrial rhythm, monomorphic isolated ventricular extrasystoles in absence of significant hyperkinetic or hypokinetic arrhythmias.
CcTGA represents approximately 0.5% of all congenital heart disease. If undiagnosed in childhood, people usually become symptomatic during the first decades of life. Dyspnea, syncope and fatigue are the most frequent symptoms detected. Cardiac conduction disorders such as atrioventricular blocks are common due to the abnormal development of cardiac structures. Quality of life and its expectancy are related to the latency of the onset of heart failure symptoms. Only few patients remain asymptomatic beyond 50 years old. Symptoms and signs are frequently due to right sided (systemic) heart dysfunction and tricuspid valve insufficiency. A particular clinical situation worthy of attention is pregnancy because of the hemodynamic imbalance occurring. In fact, cardiac output increases of 40–50% above baseline determining an augmentation of stroke volume and heart rate. For these reasons, echo surveillance is needed every 4-8 weeks because of the increased risk of acute heart failure. An accurate assessment of heart rhythm has to be done due to the known predisposition to bradyarrhythmic and tachyarrhythmic events in ccTGA.

Conclusions
CcTGA patients require a strict cardiological follow up with echocardiographic assessment and periodic heart rhythm monitoring, in order to early detect worsening of cardiac function and significant abnormalities of the rhythm.