NEUROHUMORAL AND HEMODYNAMIC MECHANISMS OF DIURESIS DURING ATRIOVENTRICULAR NODAL REENTRANT TACHYCARDIA

Thirty-two consecutive patients with paroxysmal supraventricular tachy cardias, with previously defined mechanisms of the tachycardias, were interviewed by noninvestigators about whether they experienced symptom s of diuresis during or at the termination of the tachycardias, to tes t the hypothesis that patients with AV nodal reentrant tachycardia wou ld have a feeling of diuresis, polyuria, or both during or at the term ination of the tachycardia. Twelve of the 13 patients with AV nodal re entrant tachycardia (92%), two of the 15 patients with AV reentrant ta chycardia (13%), and one of the 4 patients with atrial flutter associa ted with 2:1 AV conduction (25%) felt diuresis during or at the termin ation of the tachycardias (AV nodal reentrant tachycardia vs other for ms of tachycardia; P < 0.001). In 14 of the 32 patients, the right atr ial pressure and plasma atrial natriuretic peptide (ANP) concentration were measured during both the tachycardias and sinus rhythm. The mean right atrial pressure during AV nodal reentrant tachycardia was signi ficantly elevated compared to that during other forms of tachycardia ( P < 0.01). The plasma ANP concentration during AV nodal reentrant tach ycardia was also elevated significantly compared to that during other forms of tachycardias (P < 0.001). There were no significant differenc es in the cycle lengths of the tachycardias, age, left atrial dimensio ns, or the left ventricular ejection fraction between the AV nodal ree ntrant tachycardia and the other forms of tachycardia. We concluded th at the feeling of diuresis during or at the termination of tachycardia was a more common symptom in patients with AV nodal reentrant tachyca rdia. The higher secretion of plasma ANP from the right atrium might b e involved in the mechanism of this symptom.