Catecholamine-induced Myocarditis in a Child with Pheochromocytoma

Catecholamine-Induced Cardiomyopathy Secondary to Pheochromocytoma Rescued With Percutaneous Left Ventricular Assist Device: Novel Application of the Impella CP in a Pediatric Patient

Background: Catecholamine-induced cardiomyopathy is an uncommon complication of pheochromocytoma. Pheochromocytoma is a rare tumor that predominantly occurs in adults, making catecholamine-induced cardiomyopathy secondary to pheochromocytoma in children an exceedingly rare presentation. Treatment typically consists of medical management followed by surgical resection. Mechanical support, typically salvage therapy with extracorporeal membrane oxygenation, has been used in adult patients with cardiogenic shock and after cardiac arrest, but to our knowledge, the use of mechanical support has not been described in pediatric patients. Case Report: A 16-year-old female presented with cardiogenic shock resulting from catecholamine-induced cardiomyopathy secondary to pheochromocytoma. She was treated with a percutaneous left ventricular assist device to allow myocardial recovery while medical therapy was optimized. Given the early initiation, the patient's myocardial recovery was prompt, and only 3 days of device support were required. She was discharged in good condition and subsequently underwent uncomplicated laparoscopic resection of the tumor a few weeks later. Conclusion: In pediatric patients with catecholamine-induced cardiomyopathy secondary to pheochromocytoma, aggressive measures of support-including mechanical support and infrequently used options such as percutaneous left ventricular assist devices-should be considered early in treatment to maintain adequate cardiac output, avoid cardiac arrest, and allow for prompt myocardial recovery.

Unusual Cardiac Manifestations of a Pheochromocytoma in a Girl

We report the case of an 11-year-old girl who complained about severe asthenia, orthostatic dizziness and abdominal pain for 4 weeks. The primary investigation concluded on febrile urinary tract infection treated by antibiotics. Symptom persistence prompted cardiological and endocrinological investigations. A fluctuation in blood pressure, long QT interval, dilation of the aortic root and left ventricular hypertrophy were documented. Elevated levels of urinary catecholamines together with the presence of a right-sided adrenal mass shown via abdominal ultrasound and magnetic resonance imaging were highly suggestive of a pheochromocytoma. This was confirmed by through iodine-123-metaiodobenzylguathdine ([¹²³I]-mIBG) scintigraphy. Genetic analysis allowed for the exclusion of pathogenic mutations in genes implicated in hereditary paragangliomas and pheochromocytomas but showed a rare somatic mutation in exon 3 of the von Hippel-Lindau gene. The patient was treated with a β-blocker and calcium channel antagonist and underwent laparoscopic right-sided adrenalectomy. Cardiac manifestations resolved soon after surgery indicating that they were secondary to the pheochromocytoma. After 5 years of follow-up, the patient remains asymptomatic without any sign of tumor recurrence. The presence of aortic root dilation, a prolonged QT-interval and left ventricular hypertrophy may be early cardiac manifestations of a pheochromocytoma in a child and should prompt this diagnosis to be evoked.

Milrinone effects on cardiac mitochondria, hemodynamics, and death in catecholamine-infused rats

BACKGROUND

Catecholamine-storm is considered the major cause of enterovirus 71-associated cardiopulmonary death. To elucidate the effect of milrinone on cardiac mitochondria and death, a rat model of catecholamine-induced heart failure was investigated.

METHODS

Young male Spray-Dawley rats received a continuous intravenous infusion of norepinephrine then followed by co-treatment with and without milrinone or esmolol. Vital signs were monitored and echocardiography was performed at indicated time points. At the end of experiments, hearts were extracted to study mitochondrial function, biogenesis, and DNA copy numbers.

RESULTS

Hypernorepinephrinemia induced persistent tachycardia, hypertension, and high mortality and significantly impaired the activities of the electron transport chain and suppressed mitochondrial DNA copy number, mitochondrial transcription factor A and peroxisome proliferator-activated receptor-gamma coactivator 1-α. Norepinephrine-induced hypertension could be significantly suppressed by milrinone and esmolol. Milrinone improved but esmolol deteriorated the survival rate. The left ventricle was significantly enlarged shortly after norepinephrine infusion but later gradually reduced in size by milrinone. The impairment and suppression of mitochondrial function could be significantly reversed by milrinone but not by esmolol.

CONCLUSIONS

Milrinone may protect the heart via maintaining mitochondrial function from hypernorepinephrinemia. This study warrants the importance of milrinone and the preservation of mitochondrial function in the treatment of catecholamine-induced death.

IMPACT

Milrinone may protect the heart from hypernorepinephrinemia-induced death via maintaining myocardial mitochondrial activity, function, and copy number. Maintenance of cardiac mitochondrial function may be a potential therapeutic strategy in such catecholamine-induced heart failure.