1. From the Department of Internal Medicine and Center for Arrhythmia Research (D.P.-B., G.G.-S., C.R.V., E.N.J.-V., R.J.R., A.M.d.R., T.J.H., K.F.C., B.C.W., M.Z., K.K., H.H.V., J.J.)
2. Department of Pharmacology, School of Medicine, Universidad Complutense, Madrid, Spain (R.C., M.P.-H., M.M., E.D.)
3. Instituto de Investigación Sanitaria Gregorio Marañón, School of Medicine, Universidad Complutense, Madrid, Spain (R.C., M.P.-H., M.M., E.D.)
4. Departamento de Biología Molecular and Centro de Biología Molecular Severo Ochoa (UAM-CSIC), Universidad Autónoma de Madrid, Spain (F.J.D.-G.).
5. Department of Molecular and Integrative Physiology (F.J.A., H.H.V.)
6. University of Michigan, Ann Arbor; Centro Nacional de Investigaciones Cardiovasculares, Madrid, Spain (J.J.)
7. CIBERV, Madrid, Spain (J.J.)