Beta Blockers

Beta-blockers relax the heart muscle, allowing more blood to enter the heart between beats.

In HCM patients, beta blockers relax the heart muscle, slowing the heart rate and allowing the heart more time to fill between beats. This helps the heart circulate blood more efficiently. Beta-blocker therapy can reduce the symptoms of HCM and may improve arrhythmias.

These medications can help with symptoms such as chest pain and shortness of breath in HCM patients, both obstructed and non-obstructed. They are considered a first-line therapy for most HCM patients. When beta-blockers have too many side effects or don't work well for a patient, calcium channel blockers may be used instead. 

Beta blockers block stress hormones (e.g., adrenaline) and slow nerve impulses so the heart doesn't work as hard. Some dilate blood vessels (which lowers blood pressure) - these are the vasodilating type and should be avoided in obstructive HCM. 

Most beta blockers are generally considered safe to use during pregnancy (see table). Atenolol has some evidence of potential risk to the baby. Pregnant HCM patients on beta blockers should be carefully monitored for fetal growth, and the baby should be watched for a slow heart rate.

How often is this class used in HCM? 

12.5% of those in the HCMA database use Beta Blockers. (5.4% of completed Intakes? N=5550)

If you have trouble with a beta blocker, talk with your doctor about it!  There are many alternative drugs (some beta blockers, some not) that can be used. It may take some patience to find the combination of drugs (and doses) that works best for you.

References:

2024 AHA/ACC/AMSSM/HRS/PACES/SCMR Guideline for the Management of Hypertrophic Cardiomyopathy: https://www.ahajournals.org/doi/10.1161/CIR.0000000000001250 

Section 8.1.1. Pharmacological Management of Symptomatic Patients With Obstructive HCM

Section 8.2. Management of Patients With Nonobstructive HCM With Preserved EF

Section 9.3 Lifestyle/Pregnancy