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Discrimination of atrial fibrillation from regular atrial rhythms by spatial precision of local activation direction
A T Schoenwald1, A V Sahakian, S Swiryn
1Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208, USA.
Insights
Atrial fibrillation (AFib) can be distinguished from regular heart rhythms using a new 3D measurement of local activation direction. This method offers a precise way to identify AFib, improving diagnostic capabilities.
Area of Science:
- Cardiology
- Electrophysiology
- Biomedical Engineering
Background:
- Atrial fibrillation (AFib) is a common arrhythmia requiring accurate diagnosis.
- Distinguishing AFib from other atrial rhythms can be challenging using conventional methods.
Purpose of the Study:
- To test if variations in local activation direction can discriminate AFib from regular atrial rhythms.
- To evaluate the utility of 3D spatial precision of activation direction as a diagnostic marker.
Main Methods:
- Collected human endocardial atrial recordings during AFib, sinus rhythm, atrial flutter, and supraventricular tachycardia.
- Calculated local activation direction using a catheter with orthogonally placed electrodes.
- Quantified 3D and 2D spatial precision of activation direction in segments of 100 activations.
Main Results:
- 3D spatial precision for AFib segments (mean = 0.45) was significantly lower than for regular rhythms (>= 0.91).
- Values for 3D spatial precision ranged from 0.09-0.85 for AFib and were consistently high for regular rhythms.
- 2D spatial precision values showed overlap across all rhythm types, indicating limited diagnostic value.
Conclusions:
- Three-dimensional spatial precision of local activation direction is a valuable and effective discriminator of atrial fibrillation.
- This novel metric provides a more accurate method for identifying AFib compared to 2D analyses.
Abstract:
This study tests the hypothesis that atrial fibrillation (AFib) can be discriminated from regular atrial rhythms by a measure of the variation in local activation direction. Human endocardial atrial recordings of AFib, sinus rhythm, atrial flutter, and supraventricular tachycardia were collected using a catheter with orthogonally placed electrodes, and the direction of each activation was calculated using methods previously described by our laboratory. Each recording was divided into segments containing 100 activations, and the spatial precision for each segment was calculated in three dimensions, as well as in each of the three two-dimensional (2-D) planes. The three-dimensional (3-D) spatial precision for 1161 segments of AFib in 11 recordings ranged from 0.09-0.85 (mean = 0.45), whereas the spatial precision for 138 segments of regular rhythms in 28 recordings was > or = 0.91 in all but four instances. The 2-D spatial precision values overlapped for all rhythms. The results indicate that 3-D spatial precision of local activation direction is a useful discriminator of AFib.