Risk stratification of ventricular arrhythmias in repaired tetralogy of Fallot

Risk stratification of ventricular arrhythmias in patients with repaired tetralogy of Fallot (rTOF) remains unresolved. We aimed to identify right ventricular (RV) electrophysiological parameters potentially associated with a higher risk of ventricular arrhythmias in patients with rTOF. We included all consecutive patients with rTOF who underwent RV electroanatomical mapping at a single tertiary center. We used logistic regression modeling to identify those variables associated with an increased risk of clinical or induced ventricular tachycardia (VT), or clinical VT exclusively. Twenty-one of the 56 patients included had clinical or induced VT. A high-frequency of premature ventricular contractions/nonsustained VT (OR, 11.34; 95%CI, 1.50-85.97; P=.019), an HV interval > 55 ms (OR, 21.20; 95%CI, 3.12-144.14; P=.002), and RV activation time (ms) (OR [per 10ms intervals], 1.34; 95%CI, 1.02-1.75; P=.035) proved to be associated with clinical or induced VT. The model including this information had good discrimination ability, with an area under the curve of 0.884 (95%CI, 0.79-0.97; P 55ms (OR, 9.65; 95%CI, 1.41-66.14; P=.021) and high-frequency of premature ventricular contractions/nonsustained VT (OR, 13.14; 95%CI, 1.95-88.54; P=.008) were independently associated (area under the curve of 0.836 [95%CI, 0.663-1.000; P=.002]). High-frequency of premature ventricular contractions/nonsustained VT, an HV interval> 55ms and RV activation time are factors associated with an increased risk of ventricular arrhythmias in patients with rTOF. La evaluación del riesgo de arritmias ventriculares en pacientes con tetralogía de Fallot reparada (TFr) es compleja. Este estudio pretende identificar las características electrofisiológicas del ventrículo derecho (VD) asociadas con un mayor riesgo de arritmias ventriculares en pacientes con TFr. Se incluyó a todos los pacientes consecutivos con TFr sometidos a mapeo electroanatómico del VD en un centro terciario. Mediante modelos de regresión logística, se identificaron los factores asociados con mayor riesgo de taquicardia ventricular (TV) clínica o inducida y, secundariamente, solo de TV clínica. De los 56 pacientes incluidos, 21 presentaron TV clínica o inducida. Los factores asociados con TV clínica o inducida fueron: extrasistolia ventricular (EV) frecuente/TV no sostenida en el Holter de 24 h (OR=11,34; IC95%, 1,50-85,97; p=0,019), in