The authors found that patients with persistent atrial fibrillation (AF), compared with those with paroxysmal AF, had worse systolic circumferential left ventricle (LV) mechanics and intraventricular dyssynchrony.
The findings were based on echocardiographic assessment of strain and strain rate derived from velocity vector imaging (VVI).
Why This Matters
Accurate cardiac mechanic assessments have been historically difficult using traditional imaging modalities.
Early-stage LV mechanical impairment had been found in patients with paroxysmal AF using VVI-derived strain and strain rate.
This study adds intraventricular mechanical dyssynchrony as to possible measures associated with worsening AF.
The study compared 84 patients with nonvalvular AF (49 with paroxysmal AF, 35 with persistent AF) and 43 healthy control subjects.
Routine echocardiographic images were used to measure global longitudinal strain (GLS) and global circumferential strain (GCS).
Intraventricular dyssynchrony was measured using the standard deviation of all 12 segments.
Participants with persistent AF, compared with controls, showed significantly lower GLS (-12.23% vs -18.71%, P < .001) and GCS (-18.46% vs -28.75%, P < .001), with heart rate emerging as an independent risk predictor.
Similarly, participants with paroxysmal AF, compared with controls, showed significantly lower GLS (-17.10% vs -18.71%, P < .05) and GCS (-24.43% vs -28.75%, P < .01).
GLS and GCS were lower in patients with persistent AF than those with paroxysmal AF (P < .001 for both parameters).
Intraventricular dyssynchrony was seen in both persistent AF and paroxysmal AF groups but was more severe in those with persistent AF (P < .05).
Left ventricular ejection fraction did not differ significantly among the three groups.
Age emerged as an independent risk predictor for LV dyssynchrony.
The study is small and requires corroboration in larger studies.
Pixel-tracking VVI requires above-average image quality for optimal data extraction.
Actual VVI values may be altered by speckle pattern throughout the cardiac cycle and differences between regional resolutions.
This study was supported by grants from the Science and Technology planning project of Yantai City.
The authors have declared no competing interest.