A 65-year-old woman presented with exertional dyspnea during the follow up of Anderson-Fabry's disease (AFD). The patient had a medical history characterized by hypertension, dyslipidemia, primary antiphospholipid syndrome, cutaneous lupus disease, hypothyroidism. She presented to an AFD with scarce angiokeratomas, cornea verticillata and neurosensory hypoacusia that was confirmed by genetic testing (GLA DNA variant: p.[I270T + =] (c.[809T>C + =]) and treated with enzyme replacement therapy after diagnosis in 2016 and replaced two years later with migalastat.
She had a hypertrophic cardiomyopathy phenotype with preserved left ventricular ejection fraction (LVEF) and diastolic dysfunction. She also had a permanent bicameral pacemaker from early 2019 due to an unexplained syncope and conduction disturbances that were confirmed on a pathological electrophysiological study. During follow-up the patient also presented paroxysmal atrial fibrillation.
Physical examination noted signs of congestive right heart failure with increased jugular vein engorgement, mild peripheral oedema and no pulmonary crackles. Bedside transthoracic echocardiography showed moderate systolic dysfunction (LVEF 41%) with a new segmentary defect on inferior and lateral basal segments (video 1) as well as left ventricle global longitudinal strain (GLS) (video 2) and free wall right ventricle strain deterioration (video 3).
The main differential diagnosis proposed after the clinical findings, the LVEF deterioration and the new onset segmentary defect were coronary artery disease, recent pulmonary embolism and progression of her cardiomyopathy since inferior and lateral basal segments are usually affected by globotriaosylsphingosine (Lyso-Gb3) infiltration.
A cardiac CT scan was performed, ruling out significant coronary artery disease and pulmonary embolism. It confirmed an eccentric left ventricle (LV) myocardial hypertrophy (113 g/m2) with bi-ventricular systolic dysfunction (LVEF 38% and RVEF 42%). A mesocardial hypodense area was noted in the basal inferolateral segment of the LV consistent with the segments previously described as hypokinetic by echocardiography and a previous CMR study (figure 1). Likewise, in the present CT scan a right ventricle (RV) free wall thickening and an extensive subendo-mesocardial hypodensity of the RV free wall, basal inferior segment and RV outflow tract were observed (figure 2a). Those hypodense segments had very low attenuation Hounsfield Units (HU), leading to the suspicion of fatty infiltration in those areas. No previous RV involvement was reported in the CRM performed one year before (figure 2b).
Since ischemic or thromboembolic triggers for the functional class deterioration were ruled out disease progression was the main diagnosis. CT scan findings also explained the new segmentary defect on inferior and lateral basal LV segments as well as LV global longitudinal strain (GLS) and RV free wall strain deterioration. During hospitalization she received intravenous diuretic treatment with good response and migalastat treatment was maintained.