P591Congenital left ventricular diverticulum- an innocent bystander in a patient with hereditary hemorrhagic telangiectasia

Abstract

Congenital left ventricular diverticulum (LVD) is a rare cardiac malformation particularly when first diagnosed in adulthood, reported in 0.4% of cardiac death autopsies. LVD is frequently located at the LV apex and often associated with cardiac or extracardiac defects. In isolated cases (30%), LVD is often asymptomatic and discovered incidentally. Hereditary hemorrhagic telangiectasia (HHT) is a rare autosomal dominant disorder with significant morbi-mortality characterized by mucocutaneous telangiectasias and arteriovenous malformations. A 48-year old female presented with progressively worsening dyspnea within the last 4 years and recurrent episodes of epistaxis. She was diagnosed at the age of 20 with HHT with secondary severe anemia requiring frequent blood transfusions. An abdominal CT scan revealed multiple intrahepatic arteriovenous and arterioportal shunts and teleangiectases, while the thoracic CT scan showed no vascular anomalies. The clinical examination revealed pale skin, oral teleangiectases, moderate bilateral lower limb edema and important hepatosplenomegaly. An accentuated S2 and a grade III/VI systolic tricuspid murmur were heard. Resting ECG showed sinus rhythm and incomplete right bundle branch block with secondary repolarization changes. Lab studies revealed severe anemia, elevated serum BNP levels. The transthoracic echocardiography showed dilation of all cardiac chambers with normal left ventricular (LV) systolic function and grade III diastolic dysfunction, signs of pulmonary hypertension (PH) (estimated systolic pulmonary pressure of 85 mmHg) with mild right ventricular dysfunction, moderate tricuspid regurgitation; also, a wide outpouching extending beyond the confines of the anatomic LV chamber with normal kinetics was detected. Right heart catheterization confirmed post-capillary PH and dip-and-plateau pattern of both ventricular pressure curves, with a dia-stolic pressure difference >5 mmHg, suggestive for restrictive cardiomyopathy (RCM). The etiology of PH was considered mixed: both high cardiac output with pulmonary overload caused by multiple intrahepatic vascular shunts and possibly RCM of unclear cause. Hematological assessment excluded amyloidosis. Cardiac magnetic resonance (CMR) was performed; measured myocardial T2∗ time was within normal range and thus secondary cardiac hemochromatosis could be excluded. Nonetheless, CMR identified the LV outpouching located in the basal inferior wall, containing all three cardiac layers, with synchronous systolic contractility, suggesting a congenital LVD (Figure). The final diagnosis was PH caused by high output cardiac failure due to multiple intrahepatic vascular shunts; the patient was referred for the management of the hepatic vascular shunts. The LVD was discovered incidentally, having an uncommon location and no coexisting cardiac defects. Therefore, this is an interesting association of a rare cardiac malformation in a patient with a rare hereditary pathology, HHT.