We wish to thank Ruiz Hernández and Wangüemert Pérez for their interest in our articles.1,2
We used diagnostic criteria that were accepted at that time. With the recent consensus,3 doubts remain only about II:9, which requires the presence of ventricular premature beats or bidirectional ventricular tachycardia in relatives during the exercise stress test (EST).3 Other authors require frequent isolated ventricular premature beats.4 A family member, especially if older than 40 years, can have a few ventricular premature beats, despite having a negative genotype. Thus, the minimum number of ventricular premature beats is imprecise and two isolated premature beats appear to be insufficient to make a diagnosis of such importance for patients and their descendants.
The yield of EST varies (ranging from the 25% reported by Ruiz Hernández and Wangüemert Pérez to 100%),5 and perhaps depends on the point at which the mutation occurs. We had no intention of conveying the idea that a negative EST rules out the disease.1,2 A conclusive genetic study supports a positive EST and identifies carriers with a negative EST. In its absence, we perform Holter monitoring and an epinephrine test in relatives with a negative EST (not included in the consensus statement),3 and if they test negative, these individuals undergo follow-up with periodic EST. There are no studies on the value of epinephrine challenge in family members, but its usefulness has been documented in probands (which is included)3 and in families with cardiac arrest with preserved left ventricular ejection fraction6 and may justify its performance in the present context.
FUNDINGInstituto de Salud Carlos III, Spain, and the ERDF (PI14/01477, RD12/0042/0029, European Union, European Regional Development Fund, “A way of making Europe”); Prometeo 2011/027, Spanish Society of Cardiology (grant awarded to Pedro Zarco); and the Agence Nationale de la Recherche (ANR-13-BSV1-0023-03).