Ventricular arrhythmias following balloon-expandable transcatheter pulmonary valve replacement in the native right ventricular outflow tract.

BACKGROUND: Ventricular arrhythmia incidence in children and adolescents undergoing transcatheter pulmonary valve replacement (TPVR) within the native right ventricular outflow tract (nRVOT) is unknown. We sought to describe the incidence, severity, and duration of ventricular arrhythmias and identify associated risk factors in this population. METHODS: This was a retrospective cohort study of 78 patients <21 years of age who underwent TPVR within the nRVOT. Patients were excluded for pre-existing ventricular arrhythmia or antiarrhythmic use. Study variables included surgical history, valve replacement indication, valve type/size, and ventricular arrhythmia. Univariable logistic regression models were used to evaluate factors associated with ventricular arrhythmias, followed by subset analyses. RESULTS: Nonsustained ventricular arrhythmia occurred in 26/78 patients (33.3%). The median age at the procedure was 10.3 years (interquartle range [IQR]: 6.5, 12.8). Compared with other nRVOT types, surgical repair with transannular patch was protective against ventricular arrhythmia incidence: odds ratio (OR): 0.35 (95% confidence interval [CI], 0.13-0.95). Patient weight, valve type/size, number of prestents, and degree of stent extension into the RVOT were not associated with ventricular arrhythmia occurrence. Beta blocker was started in 16/26 (61.5%) patients with ventricular arrhythmia. One additional patient was lost to follow-up. The median beta blocker duration was 46 days (IQR 42, 102). Beta blocker was discontinued in 10 patients by 8-week follow-up and in the remaining four by 9 months. CONCLUSIONS: Though common after balloon-expandable TPVR within the nRVOT, ventricular arrhythmias were benign and transient. Antiarrhythmic medications were successfully discontinued in the majority at 6- to 8-week follow-up, and in all patients by 20 months.

Echocardiographic Assessment of Melody Versus Sapien Valves Following Transcatheter Pulmonary Valve Replacement.

OBJECTIVES: The aim of this study was to compare the immediate and midterm echocardiographic performance of the Melody (Medtronic Inc) and Sapien (Edwards Lifesciences Inc) valves after transcatheter pulmonary valve replacement (TPVR) in native and conduit right ventricular outflow tracts (RVOTs). BACKGROUND: TPVR is now a common procedure, but limited data exist comparing postimplantation echocardiographic findings between Melody and Sapien valves. METHODS: This was a single-institution retrospective cohort study of all patients who underwent successful TPVR from 2011 to 2020. Patient demographics, procedural details, and immediate and midterm echocardiographic findings were collected and compared between valve types using the Wilcoxon rank sum, chi-square, or Fisher exact test as appropriate. Subgroups were analyzed individually and were adjusted for multiple comparisons using the Bonferroni method. RESULTS: A total of 328 patients underwent successful TPVR (Melody: n = 202, Sapien: n = 126). The groups had a similar baseline age, weight, and diagnosis. The most common indications for TPVR were pulmonary stenosis (32.2%) or mixed disease (46%) in the Melody group and pulmonary insufficiency in the Sapien group (52.4%) (P < 0.001). Sapien valves were more often placed in native RVOTs (43.7% vs 18.8%; P < 0.001). The discharge and follow-up mean and peak Doppler gradients were similar between the Melody and Sapien groups. Valves implanted in native RVOTs had significantly lower postimplantation gradients at each follow-up period. CONCLUSIONS: Echocardiographic performance after TPVR was generally acceptable and similar when comparing Melody and Sapien valves despite differences in the indication and anatomy in each group. The peak and mean gradients were lower in transcatheter valves implanted in native RVOTs compared with those implanted in conduits or bioprosthetic valves.

Diarrea y Cryptosporidium en Guatemala / Diarrhea and Cryptosporidium in Guatemala

El protozoario Cryptosporidium ha sido identificado como causa de enteritis aguda en varias especies de animales. La patogénesis de esta infección aún no está clara, siendo los cuadros más severos en pacientes inmunocomprometidos. Se estudiaron 500 niños, de los cuales la mitad tenían cuadros de diarrea aguda y la otra mitad constituyó el grupo control, sin sintomatología gastrointestinal. Se utilizaron dos coloraciones, la de Giemsa y otra a base de safranina y azul de metileno (SAM). Del grupo experimental 51 (20.4%) fueron positivos para Cryptosporidium y 29 (11.5%) del grupo control también fueron positivos para este protozoario, siendo esta diferencia significativa (X**2=7.20, p < 0.01). El parásito fue más prevalente en niños mayores de cinco años que en menores de esa edad, tanto en el grupo con diarrea, como el grupo control (p < 0,05). Las únicas características que fueron más frecuentes en el grupo con diarrea y Cryptosporidium en relación al grupo con diarrea pero sin Cryptosporidium fueron: vómitos, dolor abdominal y diarrea acuosa, siendo la diferencia en estas dos últimas significativas (p < 0.05). Ambas coloraciones dieron el mismo resultado, aunque la coloración SAM es más rápida por lo que se recomienda su uso