QT prolongation with torsade de pointes in pheochromocytoma

Emergencies Caused by Pheochromocytoma, Neuroblastoma, or Ganglioneuroma

“…Although sinus tachycardia occurs most frequently, pheochromocytomas have been associated with a wide variety of arrhythmias, including supraventricular [34], nodal [35], broad complex [36], ventricular tachycardia [37][38][39], torsade de pointes [40], and Wolff-Parkinson-White syndrome [41]. Furthermore, atrial fibrillation [42] and ventricular fibrillation [5,43,44] have been reported.…”

“…These situations are the result of a reflex mechanism in which sinus slowing occurs at the onset of a sudden rise in blood pressure during a paroxysm [48]. Rarely, atrioventricular dissociation and bigeminy [34,40], right bundle branch block [49], and sick sinus syndrome [50] occur in patients with pheochromocytoma. Their treatment is similar to that in patients who do not have pheochromocytoma.…”

“…These symptoms are caused by catecholamines, which induce vasoconstriction of the coronary arteries while simultaneously increasing myocardial oxygen demand through stimulation of heart rate and cardiac contractility. The presentation and electrocardiographic changes, such as ST-segment elevation or depression [69,71,72], negative T-waves, and a prolonged QTinterval (present in 7%-35% of patients [40,73]), may resemble those of patients with myocardial ischemia or infarction due to heart disease; however, patients with pheochromocytoma may also have other symptoms due to catecholamine excess, such as severe hypertension or headache, profuse sweating, or intense pallor. A history of episodic attacks is even more helpful.…”

A case of pheochromocytoma presenting as syncope due to long QT syndrome

“…11,12 About 50-70% of all pheochromocytoma patients complain about palpitations, but only few develop ventricular tachycardia, and only a very few of these cases are reported to be due to QT interval prolongation and Torsades de Pointes. [13][14][15][16] Stenström and Swedberg have described a significant decrease in QTc interval in their retrospective study of patients after surgical removal of pheochromocytoma.…”

Emotional stress as a cause of syncope and torsade de pointes in patients with long QT syndrome

“…The rapid component of delayed rectifier potassium current (I Kr ) is modulated by -adrenergic stimulation, so the high dose of catecholamines due to intense emotional stress leads to the prolongation of QT interval particularly in patients with congenital prolonged QT interval with the consequent induction of TdP 13 . Pheochromocytoma as well as another clinical application of high-dose catecholamines like dobutamine-atropine stress echocardiography is often associated with QT prolongation and ventricular arrhythmias like torsades de pointes 13,14 .…”