Polymorphic Ventricular Tachycardia as a Manifestation of Unilateral Renal Artery Stenosis.

Renovascular hypertension (RVH) is an under-recognized but potentially reversible cause of secondary hypertension with significant cardiovascular consequences. Excess aldosterone resulting from renin-angiotensin-aldosterone system activation leads to potassium loss, QT-interval prolongation, and increased susceptibility to malignant ventricular arrhythmias. Hypokalemia combined with hypertension-mediated left-ventricular hypertrophy further increases myocardial electrical instability, predisposing to polymorphic ventricular tachycardia (PVT). We report a woman in her fifties who presented with recurrent syncope secondary to PVT associated with severe hypokalemia. Biochemical evaluation revealed elevated plasma renin activity and aldosterone with a low aldosterone-to-renin ratio. Further evaluation with CT angiography demonstrated critical unilateral atherosclerotic renal artery stenosis. Following percutaneous angioplasty and stent placement, blood pressure and serum potassium normalized, and there were no further arrhythmic episodes. This case highlights a rare but clinically important cardiovascular manifestation of unilateral renal artery stenosis presenting as polymorphic ventricular tachycardia. Recognition of hypokalemia-mediated electrophysiological instability as a reversible cause of life-threatening arrhythmia is essential, as timely revascularization can achieve complete clinical resolution.