title: Trifascicular block progressing to complete AV block on exercise: a rare presentation demonstrating the usefulness of exercise testing.
abstract: A 41-year-old man presented with dyspnoea and giddiness on exertion for the last 1 month. A resting ECG during showed trifascicular block with complete right bundle branch block, left anterior fascicular block and a prolonged PR interval of >0.24 s. His echocardiography showed no evidence of wall motion abnormality. He was subjected to a treadmill test for exercise-induced ischaemia, which showed complete atrioventricular (AV) block during first stage of Bruce protocol. His symptoms of dyspnoea and giddiness were also reproduced. The test was terminated and ECG returned to trifascicular block, similar to that at his baseline ECG during recovery. Coronary angiogram (CAG) was performed to rule out any ischaemic cause for this exercise-induced AV block, which was normal. In view of his reproducible symptoms and demonstration of complete AV block on exercise, a dual-chamber pacemaker (DDD) was implanted. His symptoms disappeared and he remained asymptomatic on follow-up.
authors.affiliation: Department of Cardiology, Kasturba Medical College, Manipal University, Manipal, Karnataka, India.
authors.forename: Ranjan K
authors.initials: RK
authors.lastname: Shetty
authors.affiliation: Department of Cardiology, Kasturba Medical College, Manipal University, Manipal, Karnataka, India.
authors.forename: Sumit
authors.initials: S
authors.lastname: Agarwal
authors.affiliation: Department of Cardiology, Kasturba Medical College, Manipal University, Manipal, Karnataka, India.
authors.forename: Naveen Chandra
authors.initials: NC
authors.lastname: Ganiga Sanjeeva
authors.affiliation: Department of Cardiology, Kasturba Medical College, Manipal University, Manipal, Karnataka, India.
authors.forename: M Sudhakar
authors.initials: MS
authors.lastname: Rao
mesh_terms: D000328:Adult; D054537:Atrioventricular Block / Q000175:diagnosis* / Q000628:therapy; D002037:Bundle-Branch Block / Q000175:diagnosis* / Q000628:therapy; D004562:Electrocardiography; D005080:Exercise Test; D006801:Humans; D008297:Male; D010138:Pacemaker, Artificial
references.citation: Pacing Clin Electrophysiol. 2000 Apr;23(4 Pt 1):527-9
references.pmid: 10793447
references.citation: Int J Cardiol. 2004 Dec;97(3):559-60
references.pmid: 15561349
references.citation: J Cardiopulm Rehabil. 2006 Sep-Oct;26(5):314-8
references.pmid: 17003598
references.citation: Chest. 1992 Sep;102(3):970-2
references.pmid: 1516440
references.citation: Chest. 1980 Aug;78(2):310-5
references.pmid: 6772388
references.citation: Nat Genet. 1999 Sep;23(1):20-1
references.pmid: 10471492
references.citation: J Cardiovasc Electrophysiol. 2014 Aug;25(8):875-81
references.pmid: 24602015
references.citation: Br Heart J. 1975 Sep;37(9):984-6
references.pmid: 1191459
references.citation: Am J Med. 1964 Nov;37:742-8
references.pmid: 14237429
references.citation: Am Heart J. 1996 Dec;132(6):1277-81
references.pmid: 8969584