Relation of interatrial block to new-onset atrial fibrillation in patients with Chagas cardiomyopathy and implantable cardioverter-defibrillators.
Chagas cardiomyopathy is an endemic disease in Latin America. A significant proportion of patients develop atrial fibrillation (AF), which may result in stroke and increased morbidity or mortality. Interatrial block (IAB) has been associated with the development of AF in different clinical scenarios. The aim of our study was to determine whether IAB can predict new-onset AF in patients with Chagas cardiomyopathy and implantable cardioverter-defibrillators (ICDs). We conducted a retrospective study of patients with Chagas cardiomyopathy and ICDs from 14 centers in Latin America. Demographics, clinical, and device follow-up were collected. Surface electrocardiograms were scanned at 300 dpi and maximized ×8. Semiautomatic calipers were used to determine P-wave onset and offset. Partial IAB was defined as a P wave of >120 ms and advanced IAB as a P wave of >120 ms with biphasic morphology (±) in inferior leads. AF events and ICD therapies were reviewed during follow-up by 2 independent investigators. A total of 80 patients were analyzed. Mean age was 54.6 ± 10.4 years, and 52 (65%) were male. Mean left ventricular ejection fraction was 40 ± 12%. IAB was detected in 15 patients (18.8%), with 8 (10.0%) partial and 7 (8.8%) advanced. During a follow-up of 33 ± 20 months, 11 patients (13.8%) presented with new AF. IAB (partial + advanced) was strongly associated with new AF (p <0.0001) and inappropriate therapy by the ICD (p = 0.014). In conclusion, IAB (partial + advanced) predicted new-onset AF in patients with Chagas cardiomyopathy and ICDs.
Queen's University, Kingston, Ontario, Canada.
Andres
A
Enriquez
Instituto Cardiovascular de Buenos Aires, Buenos Aires, Argentina.
Diego
D
Conde
Santa Clara Red de Clínicas, Mendoza, Argentina.
Francisco
F
Femenia
Cardiovascular Research Center, CSIC-ICCC, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain.
Antoni Bayés
AB
de Luna
Universidade Federal de Minais Gerais, Belo Horizonte, Brazil.
Antonio
A
Ribeiro
Hospital Fernandez, Buenos Aires, Argentina.
Claudio
C
Muratore
Sanatorio Delta, Rosario, Argentina.
Mariana
M
Valentino
Hospital Castex, Buenos Aires, Argentina.
Enrique
E
Retyk
Fundacion Favaloro, Buenos Aires, Argentina.
Nestor
N
Galizio
Queen's University, Kingston, Ontario, Canada.
Wilma M
WM
Hopman
Queen's University, Kingston, Ontario, Canada. Electronic address: barancha@kgh.kari.net.
Adrian
A
Baranchuk
D001281:Atrial Fibrillation / Q000209:etiology* / Q000503:physiopathology / Q000628:therapy; D002598:Chagas Cardiomyopathy / Q000150:complications* / Q000503:physiopathology / Q000628:therapy; D017147:Defibrillators, Implantable; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006325:Heart Atria; D006329:Heart Conduction System / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D016277:Ventricular Function, Left