Reuter H, Scholz H: A study of the ion selectivity and the kinetic properties of the calcium-dependent slow inward current in mammalian cardiac muscle. J Physiol (Lond) 264: 17-47, 1977 Singer DH, James TN, Harris P, Malm JR, Hoffman BF: Electrophysiology of chronic atrial fibrillation (abstr). Circulation 36: 239, 1967a Singer DH, Lazzara R, Hoffman BF: Interrelationships between automaticity ...