A Supraventricular Tachycardia With the Atrial Interval Variability: What Is the Mechanism? - Doi, Atsushi; Sugioka, Kazuya; Tsukamoto, Takuya; Tanaka, Sawa; Takaoka, Naoko; Iwamura, Toshiharu; Kawarabayashi, Takahiko; Fukuda, Daiju (Journal of Cardiovascular Electrophysiology, 2025)