Alcohol septal ablation in a pregnant patient with symptomatic hypertrophic cardiomyopathy

Background: Hypertrophic cardiomyopathy (HCM) is a clinically heterogeneous disease with common findings of ventricular hypertrophy and diastolic dysfunction. Sometimes the condition can lead to catastrophic cardiac events. Pregnancy poses a larger challenge, given medication restrictions and increased mortality compared to the general population. Case: A 43-year-old pregnant female with a history of HCM was referred to cardiology after a murmur was heard at her 12 week gestational appointment. Her exam revealed a grade III/VI systolic ejection murmur that increased in intensity with Valsalva. Her transthoracic echocardiogram (TTE) revealed a resting left ventricular outflow tract (LVOT) obstruction with a gradient of 70mmHg at rest. TTE was also notable for a thick basal septum, systolic anterior motion of the mitral valve and hyperdynamic left ventricular function. She had only minimal shortness of breath and no episodes of lightheadedness. She was next seen at 25 weeks of gestation, and noted progression of symptoms, including shortness of breath with minimal activity and some episodes of lightheadedness despite being on a high dose beta blocker with heart rates in the 60s. A repeat TTE at this time showed an increase in the LVOT obstruction gradient to 90 mmHg. Decision Making: The patient was started on Norpace with initial hospital observation. Unfortunately, the patient’s symptoms persisted and Norpace titration was limited due to a prolonged QTc. Given this, we proceeded with alcohol septal ablation. The procedure was successful without complication. Post-procedure, she had significant runs of symptomatic nonsustained ventricular tachycardia and received an implantable cardiac defibrillator prior to discharge. At her 1 month follow-up, her TTE showed no resting or provoked LVOT gradient and she was asymptomatic. Delivery was uncomplicated at week 37. Norpace was discontinued after delivery and patient has been maintained on beta blockade without symptoms post pregnancy. Conclusions: This case shows a detailed approach to the management of a pregnant patient with HCM. If medical therapy fails, successful alcohol septal ablation can improve the LVOT gradient and relieve symptoms