Abstract 15141: Usefulness of New Parameters Based on Frank-Starling Mechanism for Systolic and Diastolic Dysfunction in Atrial Fibrillation
Introduction: The role of Frank-Starling mechanism is well established in systolic left ventricular (LV) function. Irregular RR intervals in atrial fibrillation (AF) provide the opportunity for clinical applications of theoretical mechanism. Authors have shown that this mechanism plays a role in diastolic function in AF. We evaluated the diagnostic value of new parameters derived from Frank-Starling mechanism for both systolic and diastolic dysfunction in AF.
Methods: A total of 197 patients with AF were screened and 136 patients without exclusion criteria were enrolled. Patients were divided according to systolic function and a history of heart failure (HF). LV outflow peak ejection velocity (Vpe) was adjusted for the effect of pre-preceding RR interval (RR-2) using the logarithmic equation between RR-2 and Vpe. The logarithmic equation between adjusted Vpe and preceding RR interval (RR-1) was calculated in the coordinates with RR-1 from 0.6 to 1 second. From this equation, the ratio of slope to Vpe at RR-1 = 1 second (Slope/Vpe-1) was obtained (Fig).
Results: In all patients, the presence of HF was associated with larger LV systolic and diastolic dimensions (p<0.001), lower ejection fraction (p<0.001), thinner LV posterior wall (p=0.018), higher slope (p<0.001), and higher Slope/Vpe-1 (p<0.001). Among them, Slope/Vpe-1 and LV diastolic dimension were independent variables. AUC of Slope/Vpe-1 for identifying heart failure were 0.71 (95% CI 0.62-0.79, p<0.001, Fig). In patients with normal systolic function, the presence of HF was associated with higher slope (p=0.044) and higher Slope/Vpe-1 (p=0.005), and Slope/Vpe-1 was an independent variable. AUC of Slope/Vpe-1 for identifying heart failure were 0.64 (95% CI 0.53-0.75, p=0.018, Fig).
Conclusions: A new parameter derived from Frank-Starling mechanism might be a universal tool for the evaluation of both systolic and diastolic function in AF. Further studies is necessary for the validation of a new parameter.
- © 2012 by American Heart Association, Inc.