Electrocardiographic Characteristics and Their Correlation with Echocardiographic Alterations in Fabry Disease.

Fabry disease (FD) is an X-linked disorder with α-galactosidase A deficiency. Males (>30 years) and females (>40 years) often present with cardiac manifestations, predominantly left ventricular hypertrophy (LVH). The aim of this study was to evaluate electrocardiographic (ECG) characteristics within FD patients to identify gender related differences, and to additionally explore the association of ECG parameters with structural and functional alterations on transthoracic echocardiography (TTE). Retrospective cross-sectional analysis of 45 FD patients with contemporaneous ECG and TTE was performed and compared to age and gender matched healthy controls. FD patients demonstrated alterations in several ECG parameters particularly in males, including prolonged P-wave duration (91 vs. 81 ms, p = 0.022), prolonged QRS duration (96 vs. 84 ms, p < 0.001), increased R-wave amplitude in lead I (8.1 vs. 5.7 mV, p = 0.047), increased Sokolow-Lyon index (25 vs. 19 mV, p = 0.002) and were more likely to meet LVH criteria (31% vs. 7%, p = 0.006). FD patients with impaired basal longitudinal strain (LS) on TTE were more likely to meet LVH criteria (41% vs. 0%, p = 0.018). Those with more advanced FD (increased LV wall thickness on TTE) were more likely to meet LVH criteria but additionally demonstrated prolonged ventricular depolarization (QRS duration 101 vs. 88 ms, p = 0.044). Therefore, alterations on ECG demonstrating delayed atrial activation, delayed ventricular depolarization and evidence of LVH were more often seen in male FD patients. Impaired basal LS, a TTE marker of early cardiac involvement, correlated with ECG abnormalities. Increased LV wall thickness on TTE, a marker of more advanced FD, was associated with more severe ECG abnormalities.

Basal Segmental Longitudinal Strain: A Marker of Subclinical Myocardial Involvement in Anderson-Fabry Disease.

BACKGROUND: Cardiac involvement in Anderson-Fabry disease (AFD) is associated with increased left ventricular (LV) wall thickness. The aim of this study was to evaluate if two-dimensional global and regional strain in patients with AFD can identify early myocardial involvement (when LV wall thickness and function are normal). Additionally, the association of altered strain with adverse cardiovascular events was evaluated. METHODS: In a retrospective cross-sectional study, 43 patients with AFD, before enzyme replacement therapy (mean age, 44 ± 12 years; 58.1% men), were compared with age- and gender-matched healthy control subjects. The mean follow-up duration among patients with AFD for major adverse cardiovascular events (MACE) was 82 months. RESULTS: LV ejection fraction was similar between groups (patients with AFD vs control subjects, 61 ± 8% vs 61 ± 6%; P = .89). However, global longitudinal strain (LS) was impaired in patients with AFD compared with control subjects (-16.5 ± 3.8% vs -20.2 ± 1.7%, P < .001), with greater impairment in patients with AFD with increased LV wall thickness (-15.4 ± 3.9% vs -18.7 ± 2.3%, P < .006). Additionally, LS was most impaired in the basal segments in patients with AFD (-14.8 ± 3.7% vs -20.3 ± 1.1%, P < .001). MACE occurred in 19 of 43 patients (four women, 15 men), and Kaplan-Meier analysis demonstrated that MACE were associated with impaired basal LS. CONCLUSIONS: In patients with AFD, altered basal LS is present even in those with normal LV wall thickness and is associated with MACE. Therefore, basal LS should be considered when screening for cardiac involvement in AFD, particularly in female patients with AFD with normal LV wall thickness.

Left atrial enlargement and reduced atrial compliance occurs early in Fabry cardiomyopathy.

BACKGROUND: Fabry disease is associated with left ventricular hypertrophy (LVH) and myocardial fibrosis. The aim of this study was to evaluate left atrial (LA) size and function using tissue Doppler-derived strain in patients with Fabry disease. METHODS: Echocardiography was performed in 33 Fabry patients (14 without LVH, 19 with LVH) before commencement of enzyme replacement therapy, and results were compared with those from age-matched and gender-matched controls (n=28 and n=38, respectively). Atrial strain and strain rate were measured from four segments in the apical four-chamber and two-chamber views of the LA, and global values were calculated. Systolic strain, systolic strain rate, early diastolic strain rate, and late diastolic strain rate were measured. Phasic LA volumes and fractions were calculated. Mitral inflow and tissue Doppler E' velocities were used to estimate left ventricular (LV) diastolic function. RESULTS: LA volume was increased in Fabry patients, even in the absence of LVH. Importantly, diastolic function was normal in this subgroup without LVH, with E' velocities similar to those in controls. LA systolic strain and early diastolic strain rate were selectively reduced in Fabry patients with LVH and reflect reductions in LA and LV relaxation, respectively, consequent to increased LV mass. However, independent of LVH, both Fabry groups had significant reductions in systolic strain rate and increased LA stiffness index. CONCLUSIONS: Fabry disease is associated with LA enlargement and reduced atrial compliance that occurs before the development of LVH. This suggests that Fabry cardiomyopathy may not only cause ventricular hypertrophy and fibrosis but also alters atrial myocardial properties early in the disease process. Consequently, measurements of LA size and function may be useful in the early diagnosis of Fabry disease, before the development of LVH.

Three Adult Siblings with Mucopolysaccharidosis Type II (Hunter Syndrome): A Report on Clinical Heterogeneity and 12 Months of Therapy with Idursulfase.

Mucopolysaccharidosis type II (MPS II - Hunter syndrome) is a rare X-linked recessive disease of lysosomal glycosaminoglycan metabolism leading to a systemic storage disorder. We report three adult brothers (aged 46-52 years) with attenuated Hunter syndrome after 12 months of enzyme replacement therapy with idursulfase. Before enzyme replacement therapy, each had serious complications of their disease: in addition to all requiring urgent cervical spinal canal decompressions in middle age, one required emergency aortic and mitral valve surgery, another had stage IV airways disease, and the third had acute glaucoma resulting in unilateral blindness. One brother discontinued therapy after 12 months. The other two brothers reported subjective improvements in energy and exercise tolerance.