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Natural history of atrial fibrillation
K Hirosawa1, M Sekiguchi, H Kasanuki
1Department of Cardiology, Heart Institute of Japan, Tokyo Women's Medical College.
Insights
Atrial fibrillation is a key indicator of heart disease progression, not just hemodynamic overload. Morphological changes in atrial heart muscle and fibrosis correlate with its occurrence, highlighting its clinical significance.
Area of Science:
- Cardiology
- Pathology
- Electrophysiology
Background:
- Atrial fibrillation (AF) is a common arrhythmia with significant clinical implications in heart disease.
- Understanding the relationship between AF and various cardiac conditions is crucial for patient management.
Purpose of the Study:
- To analyze the clinical significance of atrial fibrillation in chronic and acute heart disease.
- To investigate the relationship between atrial myocardial changes and AF occurrence.
Main Methods:
- Retrospective analysis of patients with diverse heart diseases and healthy subjects.
- Histopathological and electron-microscopic evaluation of atrial heart muscle.
- Electrocardiogram (ECG) and intra-atrial electrogram recordings.
Main Results:
- AF incidence varied across different heart diseases, notably high in mitral valve disease (79.7%) and dilated cardiomyopathy (37.8%).
- Advancement of atrial myocardial morphological changes correlated with AF occurrence.
- Decreased F wave size on ECG correlated with atrial fibrosis; AF in dissecting aneurysms indicated myocardial damage.
Conclusions:
- Atrial fibrillation reflects important aspects of heart disease progression rather than direct hemodynamic overloading.
- Morphological changes and fibrosis in the atrium are closely linked to AF development.
- A quinidine treatment strategy was proposed.
Abstract:
The clinical significance of atrial fibrillation was analyzed in cases with chronic or acute heart disease and its significance at the acute and chronic stages of the disease was investigated in various disease groups. The types of disease, number of patients, and incidence of atrial fibrillation were: atrial septal defect (92, 14.1%), mitral valve disease (128, 79.7%), nonrheumatic valvular disease (32, 56.2%), aortic regurgitation (71, 2.8%), aortic stenosis (10, 10.0%), hypertrophic cardiomyopathy (181, 11.6%), dilated cardiomyopathy (111, 37.8%), acute myocardial infarction (823, 9.0%), healthy subjects (31,886, 0.3%). A histopathological and electron-microscopic evaluation of the atrial heart muscle revealed that the advancement of the morphological changes was closely related to the occurrence of atrial fibrillation. Decrease in size of F waves in the electrocardiogram correlated well with the extent of right and left atrial fibrosis. Also, it was noteworthy that the atrial fibrillation in cases with dissecting aneurysm (n = 60) was an expression of the myocardial damage due to the infiltration of the bleeding into the right atrium. Intra-atrial electrogram in 48 patients with various heart diseases revealed that the electric potentials obtained from various parts of the atrium varied to a great extent and finally the patient's condition transformed to that of atrial standstill. We conclude that atrial fibrillation is an expression of some important aspect of the progression of heart disease and is not directly associated with hemodynamic overloading to the atrium. A strategy for quinidine treatment was also introduced.