Thick and Slow Symptomatic HCM and Bradycardia: A Management Challenge
Cardiology was consulted on a 61-year-old female patient for activity-limiting shortness of breath and premature ventricular contractions. Pertinent medical history included hypertension. Upon review, an echocardiogram from the prior month revealed a left ventricular intracavitary gradient of 98 mmHg; with the Valsalva maneuver, her gradient increased to 188 mmHg. The interventricular septum thickness was 16 mm, and her left ventricular ejection fraction was hyperdynamic. She also had systolic anterior motion of the mitral valve, causing posteriorly directed mitral regurgitation. This suggested hypertrophic cardiomyopathy. She had a baseline bradycardia, with her resting heart rate in the 50s. Her medications included amlodipine and lisinopril. These medications were stopped because they could potentially increase the left ventricular outflow tract (LVOT) obstruction and filling pressure, causing hypotension and worsening symptoms. She was not willing to undergo any invasive procedures and asked about other therapeutic options. She had a normal QTc on her electrocardiogram (ECG), and there was no family or personal history of long QT syndrome.
What is the best therapeutic option for this patient?