Abstract 11600: Single-Beat Assessment of Left Ventricular Systolic and Diastolic Function During Atrial Fibrillation using Myocardial Strain and Strain Rate
Introduction: Left ventricular (LV) systolic and diastolic function during atrial fibrillation (AF) remains poorly understood due to the beat-to-beat variability and the clinical assessment is sometimes difficult. We have shown that tissue Doppler parameters at the ratio of the preceding to the prepreceding R-R interval (RR1/RR2) = 1 can be used to assess LV function in AF.
Hypothesis: LV systolic and diastolic function can be estimated from a single-beat based on RR1/RR2 in patients with AF using myocardial strain and strain rate.
Methods: Twenty-eight AF patients (mean age 66±11 years old) underwent routine echocardiographic study. Longitudinal systolic strain (LS) and diastolic strain rate (DSr) were measured by 2 different methods: 1) LS (figure, white arrow) and DSr (figure, gray arrow) were the average of instantaneous LS and DSr in 15 seconds; 2) single-beat LS and DSr were calculated at RR1/RR2=1. These indexes were compared with simultaneously measured LV pressure parameters by a 5Fr Millar catheter.
Results: There was a good positive linear relationship between the mean LS and the single-beat LS at RR1/RR2=1 (r=0.94, p<0.001) and a moderate positive linear relationship between the mean DSr and the single-beat DSr at RR1/RR2=1 (r=0.70, p<0.001). The single-beat LS correlated with the maximal positive derivative of LV pressure (dP/dt max) (r=0.79, p<0.001). The single-beat DSr correlated with the time constant of isovolumic LV pressure decay (tau) (r=-0.65, p <0.001). To investigate the independent predictors of tau, a stepwise multilinear regression analysis was used with several echocardiographic variables, and of these, the single-beat DSr was the best predictor of tau.
Conclusions: The single-beat LS and DSr represents the average value of 15 seconds in patients with AF. These non-invasively obtained single-beat parameters are useful to assess surrogate LV systolic and diastolic function even in AF.
- © 2011 by American Heart Association, Inc.