title: Progressive interatrial block and supraventricular arrhythmias.
abstract: Interatrial conduction disorders are frequent in patients with structural heart diseases, including hypertension, coronary disease, and hypertrophic cardiomyopathy, and they are strongly associated with atrial tachyarrhythmias, especially atrial fibrillation and flutter. Conduction delays lead to dispersion of refractory periods and participate in initiating and maintaining reentry circuits, facilitating atrial arrhythmias. In this case, the changing pattern over time is a manifestation of progressive atrial remodeling and conduction delay. The terminal negative component of the P wave in the inferior leads suggests block of the electrical impulse in the Bachman bundle zone, with retrograde activation of the left atria via muscular connections at the coronary sinus. This has been reproduced in experimental models and confirmed by endocardial mapping. Physicians should be aware of the association between advanced interatrial block and development of atrial arrhythmias as its recognition could prompt early and aggressive antiarrhythmic treatment.
authors.affiliation: Division of Cardiology, Queen's University, Kingston, Ontario, Canada.
authors.forename: Andres
authors.initials: A
authors.lastname: Enriquez
authors.affiliation: Cardiovascular Institute from Buenos Aires, Buenos Aires, Argentina.
authors.forename: Diego
authors.initials: D
authors.lastname: Conde
authors.affiliation: Division of Cardiology, Queen's University, Kingston, Ontario, Canada.
authors.forename: Damian P
authors.initials: DP
authors.lastname: Redfearn
authors.affiliation: Division of Cardiology, Queen's University, Kingston, Ontario, Canada.
authors.forename: Adrian
authors.initials: A
authors.lastname: Baranchuk
mesh_terms: D001145:Arrhythmias, Cardiac / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology*; D001281:Atrial Fibrillation / Q000150:complications; D001282:Atrial Flutter / Q000150:complications; D053840:Brugada Syndrome; D000075224:Cardiac Conduction System Disease; D004562:Electrocardiography; D006325:Heart Atria / Q000503:physiopathology*; D006329:Heart Conduction System / Q000002:abnormalities* / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D013610:Tachycardia / Q000150:complications
keywords: atrial fibrillation; atrial flutter; interatrial block