Introduction: The atrial fibrillation cycle length (AFCL) and the intracardiac atrial electrogram morphology may be used to characterize atrial fibrillation (AF). However, assessment of these parameters requires an invasive electrophysiological study. We assessed clinical and electrophysiological correlates of noninvasive tissue velocity imaging (TVI) of the right and left atrial myocardial fibrillatory wall motion.
Methods and results: We performed an electrophysiological study in 12 patients with AF referred for His bundle ablation. Using atrial electrograms, we determined the AFCL (AFCL-egm) and electrophysiological AF type. Simultaneously, transthoracic echocardiography was performed. We used the TVI traces to determine the cycle length of the atrial fibrillatory wall motion (AFCL-tvi) and atrial fibrillatory wall velocities (AFV-tvi). AFCL-tvi matched very well with AFCL-egm (r(2)= 0.98; P < 0.001), both in the left and right atrium. Patients with permanent AF had shorter AFCL-tvi (155 +/- 15 ms vs 216 +/- 23 ms; P < 0.001), higher AFCL-tvi variability, and lower AFV-tvi compared to patients with paroxysmal AF. Three electrophysiological AF types were found based on the morphology of the electrograms and these related to specific TVI patterns.
Conclusion: TVI of the atrial fibrillatory wall motion may enhance noninvasive characterization of atrial remodeling in patients with atrial fibrillation.