Stepan Havranek

Early Cardiac Changes in Children with Anderson–Fabry Disease

OBJECTIVE Limited evidence is available about the early cardiac manifestation of Fabry disease (FD) in children. We aimed to evaluate cardiac involvement in children with FD by analysing serial structural and electrocardiographic changes. METHODS The data were acquired from 22 children with FD [11 males; median age 9.8 (ranging 2.5-16) years]. Seven patients (5 males) were on enzyme replacement therapy (ERT) with Agalasidase alpha. Echocardiography, ECG and 24-h ECG monitoring recordings were acquired during routine annual clinical controls. ECG data were compared to a group of age-and gender-matched controls. RESULTS At baseline, ECG and ECHO parameters of left ventricular mass were similar in both males and females. Three boys (all were on ERT) developed left ventricular hypertrophy (LVH) during two-year follow-up. The progression to LVH was accompanied by the appearance of frequent ventricular premature beats in two cases and supraventricular premature beats (SPBs) with T wave inversion in one case. T wave inversion and SPBs were detected in two younger relatives of a patient with LVH, in the absence of detectable LVH. Seven out of 22 patients had T wave abnormalities. Five of them were males (p = 0.03) all carrying the N215S mutation (p = 0.03). At baseline, median PR intervals were prolonged in FD subjects compared to controls [143 (122-177) vs. 122 (82-165) ms; p < 0.0001]. CONCLUSIONS Cardiac complications of FD become apparent in childhood as subtle changes with slow but detectable progression over time, with males more frequently affected than females. Progression of LVH was apparent in three children despite ERT.

Cardiac Structural and Functional Changes in Competitive Amateur Cyclists

Purpose: To assess cardiac structural and functional changes induced by competitive amateur cycling. Methods: Fifty‐one young competitive amateur male cyclists and 47 age‐ and gender‐matched control subjects underwent complex transthoracic echocardiographic examination focused on the detailed assessment of cardiac size and function, especially of the left ventricle (LV). Subsequently, spiroergometry was performed in all study participants and its results were compared to echocardiographic data. Results: Higher left ventricular mass indexes due to the greater LV wall thickness and LV end‐diastolic diameter were found in amateur cyclists as compared to control subjects. There were no differences with regard to the LV systolic function parameters. However, significantly better indices of LV diastolic function were present in cyclists. A significant correlation between maximal oxygen pulse and LV mass index/height2.7, LV diastolic parameters and right ventricular size was noted. Conclusions: Amateur competitive cycling leads to considerable LV structural and functional changes. The increases in LV wall thickness and cavity size together with supranormal diastolic properties are key characteristics of this LV remodeling. As well, LV mass, diastolic function, and RV size are predictors of exercise capacity, indicating an important involvement of these elements in improving cardiac function with endurance training. (Echocardiography 2010;27:11‐16)

Electromuscular incapacitating devices discharge and risk of severe bradycardia

AbstractElectromuscular incapacitating devices (EMDs) are high-voltage, low-current stimulators causing involuntary muscle contractions and sensory response. Existing evidence about cardiac effects of EMD remains inconclusive. The aim of our study was to analyze electrocardiographic, echocardiographic, and microvolt T-wave alternans (MTWA) changes induced by EMD discharge.We examined 26 volunteers (22 men; median age 30 years) who underwent single standard 5-second duration exposure to TASER X26 under continuous echocardiographic and electrocardiographic monitoring. Microvolt T-wave alternans testing was performed at baseline (MTWA-1), as well as immediately and 60 minutes after EMD exposure (MTWA-2 and MTWA-3, respectively).Mean heart rate (HR) increased significantly from 88 ± 17 beats per minute before to 129 ± 17 beats per minute after exposure (P < 0.001). However, in 2 individuals, an abrupt decrease in HR was observed. In one of them, interval between two consecutive beats increased up to 1.7 seconds during the discharge. New onset of supraventricular premature beats was observed after discharge in 1 patient. Results of MTWA-1, MTWA-2, and MTWA-3 tests were positive in one of the subjects, each time in a different case.Standard EMD exposure can be associated with a nonuniform reaction of HR and followed by heart rhythm disturbances. New MTWA positivity can reflect either the effect of EMD exposure or a potential false positivity of MTWA assessments.