ß blockers should be avoided in which of the following conditions?
A. Bronchoconstriction
B. Hypertension
C. Angina
D. Myocardial infarction
Correct Answer: A. Bronchoconstriction
ß blockers should be avoided in bronchoconstrictive disease. Traditionally, beta-blockers have been contraindicated in asthmatic patients. However, recommendations have aligned for allowing cardio-selective beta-blockers, also known as beta-1 selective, in asthmatics but not non-selective beta-blockers.
Option B: Patients who have either acute or chronic bradycardia and/or hypotension have relatively contraindication to beta-blocker usage. The patient’s heart rate and blood pressure require monitoring while using beta-blockers. Beta receptors are found all over the body and induce a broad range of physiologic effects. The blockade of these receptors with beta-blocker medications can lead to many adverse effects. Bradycardia and hypotension are two adverse effects that may commonly occur.
Option C: All beta-blockers, especially in patients with cardiac risk factors, carry a risk of heart block. The negative chronotropic and inotropic effects lead to a decreased oxygen demand; that is how angina improves after beta-blocker usage. These medications also prolong the atrial refractory periods and have a potent antiarrhythmic effect.
Option D: Once beta-blockers bind to the B1 and B2 receptors, they inhibit these effects. Therefore, the chronotropic and inotropic effects on the heart undergo inhibition, and the heart rate slows down as a result. Beta-blockers also decrease blood pressure via several mechanisms, including decreased renin and reduced cardiac output.