To the Editor: Awareness about atypical and malignant modes of presentation of a clinical condition can avoid catastrophic outcomes, assist in correct diagnosis in the appropriate clinical setting and, as typified by the following case, offer complete cure.

A 39-year-old woman presented with a 5-year history of intermittent, recurrent brief syncopal episodes. During an episode at presentation, telemetry showed torsade de pointes with ventricular fibrillation (Box), and external defibrillation was required to restore sinus rhythm. Amiodarone infusion was initiated at a local hospital before the patient was referred to our institution for further investigation and management.

On presentation, her heart rate was 50 beats/min and her blood pressure was 170/95 mmHg. No other abnormalities were detected on examination. A resting electrocardiogram (ECG) showed prominent U waves, with a long QT interval (QTc of 540 ms). As the patient had mild hypokalaemia (serum potassium level, 3.1 mmol/L), mild hypocalcaemia (serum calcium level, 2.10 mmol/L) and a prolonged QT interval, the amiodarone infusion was discontinued, and supplementation with potassium and calcium was initiated. In view of the hypertension and hypokalaemia, primary aldosteronism was suspected.

Serum cortisol, 24-hour urinary cortisol and 24-hour urinary catecholamine levels were normal. The plasma aldosterone/renin ratio was markedly elevated (1920/1.2 = 1595; normal, < 99). Failure of aldosterone suppression after acute saline loading was also noted. Computed tomography of the abdomen showed a right adrenal ovoid mass (1.9 × 1.2 cm). Adrenal vein sampling confirmed right lateralisation (right to left ratio, 40 : 1; aldosterone level in the right vein was 224 000 pmol/L while that in the left vein was 5570 pmol/L).

Despite initial potassium supplementation, the hypokalaemia persisted and only improved after initiating diuretic therapy with amiloride. Two weeks later, laparoscopic right adrenalectomy was performed, and adrenocortical adenoma was confirmed histologically. After surgery, plasma aldosterone and renin levels normalised to 106 pmol/L and 8.9 mU/L, respectively. Nine months later, the patient was normotensive (without treatment) and had a normal ECG with no further recurrence of arrhythmias.

This was a case of primary aldosteronism presenting as aborted sudden cardiac death and malignant syncope secondary to hypokalaemia-induced torsade de pointes. Most patients with primary aldosteronism are either asymptomatic or have symptoms related to hypertension or hypokalaemia (eg, polyuria, cramps, paraesthesia or muscle weakness); the diagnosis is often missed because of the non-specific clinical features. Primary aldosteronism presenting with cardiovascular collapse caused by hypokalaemic torsade de pointes and recurrent ventricular fibrillation is extremely rare, as is presentation as sudden cardiac death secondary to ventricular fibrillation.1 A prolonged QT interval has been reported in cases of primary aldosteronism,2 with values normalising after adrenalectomy.3

Torsade de pointes noted on telemetry in a 39-year-old woman