In a placebo-controlled study of 13 subjects with systemic hypertension, sustained-release verapamil reduced the morning surge in systolic pressure by 10.2 mm Hg (p = 0.04), diastolic pressure by ...11.1 mm Hg (p = 0.008), and heart rate by 3.3 beats/min (p = 0.17). Blunting of the morning hemodynamic surge may be a mechanism by which verapamil could reduce the risk of plaque disruption and acute coronary events in the morning.