P2A221: A Case of Severe Asthma Revealing Hypertrophic Cardiomyopathy

Introduction: Asthma is a common condition affecting the pediatric population. We describe a patient whose presentation of status asthmaticus revealed an additional diagnosis of hypertrophic cardiomyopathy.

Case Description: A 14-year-old male with history of mild persistent asthma presented to the Emergency Department with difficulty breathing secondary to status asthmaticus. He received continuous albuterol, ipratropium bromide, methylprednisolone, magnesium sulfate, and was initiated on noninvasive positive pressure. After admission to the pediatric ICU, he developed profound hypotension and ventricular ectopy. Point-of-care ultrasound revealed severe left ventricular hypertrophy. He was subsequently transferred to the cardiac ICU for further care. His hypotension persisted despite volume resuscitation and initiation of phenylephrine and vasopressin infusions. Concurrently, he developed acute hypoxemic respiratory failure despite treating his asthma. Given his cardiopulmonary deterioration, he was cannulated to veno-arterial (VA) ECMO with a 25Fr venous drain in the femoral vein, 17 Fr arterial return in the femoral artery plus a 6 Fr reperfusion catheter. An additional return was placed in the right internal jugular to combat harlequin syndrome.
He remained on VA-V ECMO for 6 days. His asthma was difficult to manage due to his new diagnosis of hypertrophic cardiomyopathy and the need for judicious use of beta-agonist therapy. Multiple therapies were trialed to reverse his bronchospasm. During his ECMO run, he required isoflurane with vasoactive support to prevent hypotension. Following discontinuation of isoflurane, he was started on an aminophylline infusion for continual control of bronchospasm. He remained on aminophylline through ECMO decannulation.
Throughout his course he developed persistent cardiac arrhythmias including episodes of ventricular tachycardia and supraventricular tachycardia with aberrancy, requiring chemical and electrical cardioversion as well as initiation of anti-arrhythmic agents.
Following ECMO decannulation and stabilization, further investigation was conducted, including genetic testing and cardiac MRI. MRI revealed a pattern of hypertrophy and scarring concerning for Danon Disease, a rare lysosomal storage disease that causes hypertrophic cardiomyopathy, Wolff-Parkinson White, skeletal muscle weakness, and mild intellectual disability, all of which our patient exhibited.

Discussion: Severe asthma exacerbation and hypertrophic cardiomyopathy with concomitant hemodynamic instability poses a formidable management challenge. Many effective and first-line asthma therapies such as inhaled and IV beta agonists induce tachycardia and can be arrhythmogenic, both of which are detrimental to cardiac output in the setting of hypertrophic cardiomyopathy. In the case of our patient, extracorporeal support proved beneficial in controlling both of his conditions, but not without complication.
This case also highlights the additional modalities of asthma treatment and the challenges of employing them.

Conclusion: This case showcases the very rare condition of hypertrophic cardiomyopathy and WPW secondary to Danon Disease brought to light in the setting of a very common presentation of asthma. Our patient’s course highlights the difficulties in co-managing competing physiologies while on and off extracorporeal support.