Assessment of LV systolic function in atrial fibrillation using an index of preceding cardiac cycles

Tomotsugu Tabata, Richard A. Grimm*, Neil L. Greenberg, Deborah A. Agler, Kent A. Mowrey, Don W. Wallick, Youhua Zhang, Shaowei Zhuang, Todor N. Mazgalev, James D. Thomas

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

39 Scopus citations


The clinical assessment of left ventricular (LV) systolic function during atrial fibrillation (AF) is unreliable and difficult because of beat-to-beat variability. We evaluated an index for the estimation of LV systolic function in AF that is based on the relationship between the preceding (R-R1) and prepreceding (R-R2) R-R intervals. LV Doppler stroke volume (SV), ejection fraction (EF), peak aortic flow rate (AoF) and the maximum value of the first derivative of the LV pressure curve (dP/dtmax) were evaluated in 13 healthy open-chest dogs during triggered AF. All parameters showed a significantly strong positive linear relationship with the ratio of R-R1/R-R2 (r = 0.65, 0.74, 0.75, and 0.70 for SV, EF, AoF, and dP/dtmax, respectively). The calculated value of LV systolic parameters at R-R1/R-R2 = 1 in the linear regression line showed a good relationship and an agreement with the measured average value of the parameter over all cardiac cycles (SV, 12.1 vs. 12.8 ml; EF, 49.6 vs. 51.2%; AoF, 1.37 vs. 1.48 l/min; and dP/dtmax, 2,323 vs. 2,454 mmHg/s). Using the LV systolic parameters estimated at R-R1/R-R2 = 1 in the linear regression line allows the LV contractile function to be accurately and reproducibly evaluated during AF and obviates the less-reliable process of averaging multiple cardiac cycles.

Original languageEnglish (US)
Pages (from-to)H573-H580
JournalAmerican Journal of Physiology - Heart and Circulatory Physiology
Issue number2 50-2
StatePublished - 2001


  • Afterload
  • Contractility
  • Echocardiography
  • Left ventricular
  • Preload
  • R-R interval

ASJC Scopus subject areas

  • Physiology
  • Cardiology and Cardiovascular Medicine
  • Physiology (medical)


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