Abstract 13492: Usefulness of Aortic Valve Area Measurement Obtained by Single-Beat Recording of Double-Envelope Technique in Patients With Aortic Stenosis and Atrial Fibrillation

Abstract

Introduction: In patients with aortic stenosis (AS) and atrial fibrillation (AF), the conventional continuity equation to evaluate aortic valve area (AVA) is cumbersome, because 5 to 10 cycles are required to ensure accuracy of results. Double-envelope (DE) is obtained by a single continuous-wave Doppler envelope with double density velocity profiles; the inner envelope represents flow across the left ventricular outflow tract and outer envelope represents flow across the aortic valve orifice. Hypothesis: The aim of this study to evaluate the usefulness of the AVA calculated from single-beat recorded inner and outer envelopes in patients with AS and AF. Methods: Eighteen AS patients (74.6±7.2 years old) with AF were examined by transthoracic echocardiography. The conventional AVA (PW/CW technique) was calculated from nonsimultaneously measured LVOT flow and AVO flow in randomly picked up 8 cardiac cycles, respectively. The AVA (DE technique) was calculated from the inner and outer envelopes simultaneously recorded. A single-beat AVA was calculated from simultaneously recorded inner and outer envelopes (by DE technique) when the preceding RR interval/pre-preceding RR interval = 1. Bland-Altman analysis was used to compare the results of two techniques and estimate the reproducibility. Results: DE profiles were successfully obtained in all patients, and mean AVA (PW/CW technique) was 1.09±0.19 cm2. AVA by Single-beat DE technique showed good correlation with that by PW/CW technique (r=0.90), and the mean bias in the AVA measurements between by PW/CW technique and by DE technique was 0.048 cm2. (Figure) Conclusions: AVA in patients with AS and AF obtained by Single-beat DE technique was feasible and in good agreement with that by PW/CW technique. We suggest that DE technique should be considered to estimate the subtle temporal change of AVA in patient with AS and AF more simply and accurately.