Beta Blockers

Question 1

Epi vs. NE R Specificity

Answer 1

Beta more vs. alpha more

Question 2

Beta Subtype Distribution (& how CAT specificity is affected)

Answer 2

More Beta1 in heart causing increased HR and contraction
More Beta2 in periphery for dilatation and relaxation
So epi infusion gives you increased HR and peripheral dilatation, and NO gives you increased HR and constriction

Question 3

BetaR Sensitization

Answer 3

Agonists desensitize by ligand dependent phospho and internalization w/ chronic stress, so myocardium in heart failure unresponsive to epi and Beta agonists. Antagonists allow re-sensitization and heart failure saving

Question 4

Effect of Beta Blockers on HR

Answer 4

Put a “ceiling” on HR, don’t actively lower below pacemaker intrinsic rate

Question 5

6 Indications for BBs

Answer 5

HTN
Chronic CHF
Afib
Symptomatic premature beats (ectopy)
Perioperative cardioprotection
Prevention of post-MI remodeling

Question 6

BBs in HTN

Answer 6

Pretty shitty because BP determined more by PVR. Might work for people who get super pissed off easily

Question 7

2 Anti-B1 Selective Drugs

Answer 7

Atenolol

Metoprolol

Question 8

Use of Anti-B1 Selective Drugs

Answer 8

Slow HR and contractility and don’t want to block B2s in asthmatics

Question 9

Use of Anti-B2 Selective Drugs (2)

Answer 9

Vasoconstrictor effects and reduce intraocular pressure

Question 10

Polarity Spectrum

Answer 10

More polar (atenolol) have decreased excretion and fewer CNS effects. Less polar (propanolol) are opposite

Question 11

Inverse Agonist Effect

Answer 11

Lock R in inactive configuration, preventing intrinsic rate

Question 12

Anti-Arrhythmic Effects of BBs (all and 1 specific)

Answer 12

All slow AV node conduction (prevent Afib irregular contractions)
Sotalol blocks K channels so used for Vfib

Question 13

B Adrenergic Activation in CHF

Answer 13

Get R loss and tachycardia, and then Ca overload causes arrhythmias and can lead to sudden death (overtime!)

Question 14

Chronic Beta R Stimulation Worsening Heart Failure

Answer 14

Get abnormal myocyte growth, leading to energy inefficiency, leading to myocyte death, leading to replacement myocardial fibrosis/adverse remodelling and scarring

Question 15

BBs in CHF

Answer 15

Slow HR and permit longer filling times and prevent all that other shit I just talked about. In general BBs prevent mortality from heart failure by about one metric assload

Question 16

BBs in Chronic CAD

Answer 16

1st line agents to relieve angina and protect from ischemic heart disease bc slow everything down

Question 17

Perioperative BBs

Answer 17

If pt at risk for MI or Afib

Question 18

6 Contraindications for BBs

Answer 18

CNS Side Effects (Depression, ED, etc)
Co-existing COPD/asthma
Dyslipidemia (have to ignore bc everybody has)
Diabeetus
Acute Symp Activation
Stress Testing