ECG Findings and Management in Pheochromocytoma
Characteristic ECG Abnormalities
- The most characteristic ECG manifestation of pheochromocytoma is QT‑interval prolongation, which may be accompanied by ventricular arrhythmias, ST‑T segment changes that mimic acute myocardial infarction, and prominent U waves. (American Heart Association) 1, 2, 3
- A prolonged QT interval is the hallmark ECG finding in patients who develop ventricular tachycardia secondary to pheochromocytoma. (American Heart Association) 1, 2, 3, 4, 5
- QRS complex prolongation can occur in the setting of electrolyte disturbances caused by catecholamine excess. (American Heart Association) 1, 2, 3, 4, 5
Arrhythmia Risk and Pharmacologic Management
- Ventricular tachycardia and sudden cardiac death may arise in pheochromocytoma, although the overall incidence appears low; risk is heightened when catecholamine‑induced reversible hypertrophic or dilated cardiomyopathy is present. (American Heart Association) 1, 2, 3
- Both supraventricular and ventricular arrhythmias that persist after adequate alpha‑blockade should be managed with beta‑blockade. (American College of Endocrinology) 6, 7, 8
Reversibility with Alpha‑Blockade and Surgical Resection
- ECG abnormalities caused by catecholamine excess are typically reversible after appropriate alpha‑adrenergic blockade and definitive tumor resection. (American Heart Association) 1, 2, 3
Preoperative and Intraoperative Management
- Preoperative alpha‑adrenergic blockade (e.g., phenoxybenzamine or doxazosin) reduces the recurrence of ventricular arrhythmias in patients undergoing surgery for pheochromocytoma. (American Heart Association) 1, 2, 3
- Early definitive surgical removal of the tumor is recommended when life‑threatening arrhythmias have been documented. (American Heart Association) 1, 2, 3
- During surgery, intra‑operative ventricular arrhythmias are treated with intravenous lidocaine. (American College of Endocrinology) 6, 7