Mechanism of anti-hypertensive action of beta blockers

In current medical practice, beta blockers are classified into three classes

👄 Non-selective beta blockers (blocks both beta 1 and beta 2 receptors): 

            ACUTE EFFECT

                    Beta 1 blockade: 

                            👉 Decreased heart rate and decreased cardiac contractility

                            👉 Decreased cardiac output

                            👉 Systolic BP tends to decrease

                    Beta 2 blockade:

                            👉 Increased peripheral vascular resistance

                            👉 Diastolic BP tends to increase

               NET ACUTE EFFECT: No change in BP

                

               PROLONGED USE EFFECT:

                            👉 Decreased cardiac output

                            👉 Adaptation of resistance vessels to persistently reduced cardiac output

                            👉 Decrease in peripheral resistance

                            👉 Systolic BP decreases due to decreased cardiac contractility

                            👉 Diastolic BP decreases due to decreased peripheral resistance

                            

👄 Selective beta blockers (blocks only beta 1 receptor)

            

        ACUTE EFFECT

                    Beta 1 blockade: 

                            👉 Decreased heart rate and decreased cardiac contractility

                            👉 Decreased cardiac output

                            👉 Systolic BP tends to decrease

        

        PROLONGED USE EFFECT:

                            👉 Decreased cardiac output

                            👉 Adaptation of resistance vessels to persistently reduced cardiac output

                            👉 Decrease in peripheral resistance

                            👉 Systolic BP decreases due to decreased cardiac contractility

                            👉 Diastolic BP decreases due to decreased peripheral resistance

                            

👄 Beta blockers with additional alpha blocking property

 

    ACUTE EFFECT

                    Beta 1 blockade: 

                            👉 Decreased heart rate and decreased cardiac contractility

                            👉 Decreased cardiac output

                            👉 Systolic BP tends to decrease

                   Alpha blockade:

                             👉Decrease in total peripheral resistance

                             👉 Decrease in diastolic BP

                             👉 Compensatory increase in heart rate blockade by beta 1 receptor blockade