Propanolol is a nonselective beta blocker:

• Blockade of beta-1 receptors: beta-1 typically cause an increase in heart rate, so blockade causes decrease in heart rate and contractility. CO = HR x SV so there is an overall decrease in cardiac output
• Blockade of beta-2 receptors: beta-2 receptors normally cause relaxation of smooth muscle and vasodilation, so blockade causes constriction and therefore increases total peripheral resistance (decreased radius leads to increased resistance)