Mattioni TA, Zheutlin TA, Sarmiento JJ, Parker M, Lesch M, Kehoe RF. Amiodarone in patients with previous drug-mediated torsade de pointes. Long-term safety and efficacy. Ann Intern Med. 1989 Oct 01;111(7):574–80. doi: 10.7326/0003-4819-111-7-574. PMID: 2774388.