Cardiac rhythm in hypertension assessed through 24 hour ambulatory electrocardiographic monitoring. Effects of load manipulation with atenolol, verapamil, and nifedipine. Issue 2 (August 1983) - Loaldi, A; Pepi, M; Agostoni, P G; Fiorentini, C; Grazi, S; Della Bella, P; Guazzi, M D