P1336 Sometimes the heart could appear different if seen under a magnetic resonance scanner: misdiagnosed cases of isolated left ventricle apical hypoplasia and double chambered left ventricle
Authors: Trocchio G , Moscatelli S , Stagnaro N , Rizzo F , Ait-Ali L , Festa P , Magnano G , Marasini M 
Published: January 2020

Abstract

Introduction
Congenital heart diseases (CHD) are detected in 1% of children, often usually the first year of life; however, many defects are diagnosed later or remain undiagnosed. Both congenital and acquired disorders could affect the left ventricle (LV). First-line assessment includes echocardiography; nonetheless, because of intrinsic or technical limitations and artefacts, further investigation may be required. Cardiac Magnetic Resonance (CMR) is capable of providing anatomical and functional information without many of limitations and drawbacks of echocardiography. We describe CMR findings of misdiagnosed cases of two rare congenital LV abnormalities: isolated LV apical hypoplasia (ILVAH) and double-chambered LV (DCLV).
Case report 1 (image A,B,D)
An 18 yrs girl diagnosed with dilated cardiomyopathy (DCM) was submitted to our CMR Lab for a functional assessment. After birth, deep Q waves in the inferior leads were noted on the ecg, and an echocardiographic examination showed a dilated and hypokinetic LV. At 1 year of age, she underwent cardiac catheterization that excluded coronary arteries anomalies and confirmed a reduced LV systolic function. A diagnosis of idiopathic DCM was formulated and she was initiated with anticongestive therapy. During the follow-up she felt well with normal exercise tolerance, longitudinal echocardiography did not show any substantial modification over the years. In 2018, a CMR study was performed. Surprisingly, the cardiac apex was formed exclusively by the right ventricle, wrapped around the LV. The LV appeared spherical and truncated inferiorly, and the apical portion was missing; LV volumes and ejection fraction were normal; regional akinesia and subendocardial late gadolinium enhancement (LGE) were evident at the inferior wall. These findings were consistent of ILVAH.
Case Report 2 (image C,E,F)
A 24 yrs old boy with prenatal diagnosis of LV diverticulum came to our observation for a CMR study. He was asymptomatic, particularly, no palpitations or syncope were referred, nor arrhythmias were detected during the follow-up; exercise tolerance was normal. CMR showed a coarse muscle band in the LV cavity, extending from the apex to the posterior papillary muscle, thus delimiting a contractile accessory chamber. LV volumes and global systolic function were normal. The LV accessory chamber presented a normal structured free lateral wall with a normal systolic thikening, except at the apical infero-lateral segment where it appeared thinned and akinetic and showed LGE with a subendocardial pattern. These findings were consistent of DCLV.

Conclusions
the LV could be affected by many diseases with different etiological, clinical and morphological features. Compared to other imaging diagnostic modalities, CMR allows better definition of LV morphology, function and tissue characterization, becoming essential for LV abnormalities diagnosis and follow-up.
Abstract P1336 Figure.