Iranian Heart Association Iranian Heart Journal 23 4 2022 10 01 An Uncommon Type of Bundle Branch Reentrant Tachycardia in Hypertrophic Cardiomyopathy 131 134 158161 EN Zahra Emkanjoo Cardiac Electrophysiology Research Center, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, IR Iran. Shabnam Madadi Cardiac Electrophysiology Research Center, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, IR Iran. 0000-0002-7543-8424 Seyed Mahdi Rezvanjoo Department of Cardiology School of Medicine, Hamadan University of Medical Sciences, Hamadan, IR Iran. Journal Article 2021 09 10 Bundle branch reentrant tachycardia (BBRT) is an uncommon ventricular tachycardia (VT) and is presented with a long His-ventricular (H-V) interval as a reentry between the bundle branches. This arrhythmia is frequently seen in patients with a significant conduction system disorder. QRS morphology during VT is usually the left bundle branch block (LBBB) type and may be similar to that in sinus rhythm. While BBRT usually has LBBB-like morphology, in rare cases it can be seen with the right bundle branch block (RBBB) form. Most patients have prolonged H-V intervals during sinus rhythm, consistent with His–Purkinje disease; however, some patients may have normal H-V intervals. The ablation of RBBB can cure it, but up to 30% of patients may need pacemaker implantation after ablation. BBRT is responsible for about 6% of induced VTs during the electrophysiology study. We herein present an uncommon form of BBRT (the RBBB type) in a patient who had hypertrophic cardiomyopathy with a normal left ventricular function. <strong><em>(Iranian Heart Journal 2022; 23(4): 131-134)</em></strong> https://journal.iha.org.ir/article_158161_b997b43c9b4f0ed1bd3194ddb85fe866.pdf