Supraventricular tachycardia

To the Editor: I read with interest the article by Medi and colleagues,1 but note that the authors do not mention the effect of supraventricular tachycardia on atrial natriuretic peptide — a hormone that causes vasodilation and renal excretion of sodium and water. Plasma levels of atrial natriuretic peptide increase markedly during supraventricular tachycardia.2 Pacing studies reveal that release of atrial natriuretic peptide occurs when the heart rate is greater than 120 beats/min.3 The resultant diuresis would lead to an urge to urinate and, in a prolonged episode of tachycardia, to polyuria.4,5