If heart rate is 90 to 100 beats per minute in a pregnant woman with Marfan syndrome, which measure is considered appropriate?

• A. Consider beta blocker therapy
• B. Avoid beta blockers
• C. Administer ACE inhibitors
• D. Use calcium channel blockers only

Answer: (A)

In Marfan syndrome during pregnancy, the focus is on reducing the heart’s workload to protect the aorta from dilation or dissection. Beta blockers achieve this by lowering heart rate and the force of cardiac contraction, which in turn reduces the rate of rise in aortic pressure (dP/dt). With a heart rate in the 90s to 100s, using a beta blocker helps blunt the hemodynamic stress on the aorta, slowing dilation and lowering the risk of dissection as pregnancy progresses. Labetalol or other beta-blockers are commonly used in this context because they can safely lower heart rate and provide arterial pressure control for both mother and fetus when monitored appropriately.

ACE inhibitors are not chosen in pregnancy due to known fetal risks, including renal and limb anomalies, so they’re not appropriate here. Calcium channel blockers can be part of management but are not the sole or primary measure for protecting the aorta in Marfan during pregnancy; relying on them alone misses the protective effect on aortic wall stress provided by beta blockade.