Right Ventricular Hypertrophy, Systolic Function, and Disease Severity in Anderson-Fabry Disease: An Echocardiographic Study

Background Right ventricular (RV) involvement has been described in Anderson-Fabry disease (AFD), especially in patients with established Fabry cardiomyopathy (FC). However, few and controversial data on RV systolic function are available, and there are no specific tissue Doppler studies. Methods Detailed echocardiographic examinations were performed in 45 patients with AFD. FC, defined as maximal left ventricular wall thickness ≥ 15 mm, was present in 12. The Mainz Severity Score Index was calculated for each patient. Pulsed tissue Doppler was applied to the RV free wall at the tricuspid annular level and at the septal and lateral corners at the mitral annular level to obtain systolic tissue Doppler velocities (RV Sa, septal Sa, and lateral Sa, respectively). Twelve patients with amyloid light-chain cardiac amyloidosis were studied as a control group. Results Echocardiography revealed RV hypertrophy (RVH) in 31% of patients with AFD, all but one of whom were male and all of whom had concomitant left ventricular hypertrophy (LVH). All patients with AFD had normal RV fractional area change (47.9 ± 6.5%) and tricuspid annular plane systolic excursion (21.7 ± 3.2 mm) and all but one also had normal RV Sa (13.2 ± 2.2 cm/sec). RVH positively correlated with indices of LVH (r = 0.8, P = .0001, for all parameters evaluated), as well as with Mainz Severity Score Index (r = 0.70, P = .0001). Septal and lateral Sa were decreased in almost all patients (means, 7.7 ± 1.8 and 7.9 ± 1.9 cm/sec, respectively), irrespective of the presence of LVH. Compared with control subjects with cardiac amyloidosis, patients with FC showed better indices of RV systolic function (P < .001 for all: tricuspid annular plane systolic excursion, RV fractional area change, and RV Sa) despite similar RV wall thickness (6.2 ± 1.2 vs 6.9 ± 1.9 mm, P = NS). Conclusions RVH is common in patients with AFD and correlates with disease severity and LVH. RVH, however, does not significantly affect RV systolic function. Patients with FC have better RV systolic function compared with those with cardiac amyloidosis with similar levels of RV thickness. The combination of low LV Sa values and normal RV Sa values might be helpful in the differential diagnosis of infiltrative heart disease.