Assessment of Doppler-derived Aortic Flow in Atrial Fibrillation Using Beats with Equal Subsequent Cycles

應用前兩心跳週期相同之心跳評估心房纖維顫動時的經主動脈瓣杜普勒血流量

王俊力(Chun-Li Wang) ； 陳偉踐(Wei-Jan Chen) ； 賀萬靖(Wan-Jing Ho) ； 許隆安(Lung-An Hsu) ； 鄭乃仁(Nye-Jan Cheng) ； 許子秀(Tsu-Shiu Hsu) ； Nazar Luqman ； 郭啟泰(Chi-Tai Kuo)

《Acta Cardiologica Sinica》 22卷1期 (2006/03) Pp. 16-23

摘要

背景　先前的研究發現前兩心跳週期相同（定義為心跳週期誤差在百分之五以內）之心跳，取二至三個心跳平均可運用於預測心房纖維顫動病患20個心跳週期的平均值。而取心跳週期誤差在百分之十以內之心跳是否可以運用來預測，目前並不清楚。
方法　我們收集了120位心房纖維顫動患者的資料，於每一個患者分析及測量流經主動脈瓣杜普勒血流量至少連續20個心跳週期，比較取心跳週期誤差在百分之五以內及取心跳週期誤差在百分之十以內來預測之兩種方法之間，是否有所不同。
結果　於心跳週期小於0.5秒的心跳其數值容易低估20個心跳的平均值，在分析時須加以排除。而相符性分析及平均差比較分析顯示，取心跳週期誤差在百分之五以內及取心跳週期誤差在百分之十以內來預測之兩種方法，於排除小於0.5秒的心跳及取二至三個心跳平均後，準確度並無不同。在臨床運用上取心跳週期誤差在百分之十以內之心跳來預測20個心跳的平均值，相對容易許多。
結論　在臨床上可以取三個心跳週期誤差在百分之十以內及排除週期小於0.5秒的心跳，準確地評估心房纖維顫動患者之經主動脈瓣杜普勒血流量。

關鍵字

心房纖維顫動 ； 左心室 ； 心搏出量 ； 收縮期 ； 心室功能

並列摘要

Background: Prior studies have demonstrated that during atrial fibrillation (AF), beats with equal preceding and pre-preceding R-R intervals, defined as intervals differing less than 5%, could be used to determine the mean values instead of measuring over 20 cardiac cycles. It is not known whether beats with interval difference less than 10% could be used in the same way.
Methods: In 120 patients with AF, Doppler aortic flow time-velocity integral was determined for at least 20 consecutive cardiac cycles. The values at beats with interval difference of less than 5% and less than 10% were chosen. These were then compared with the measured average values over all cardiac cycles.
Results: Agreement and mean percentage difference analyses revealed that the accuracy of measurements using inter-beat variability less than 10% was similar to that using less than 5% for 2- and 3-beat analyses provided the R-R intervals were longer than 500 milliseconds. The values at beats with cycle lengths shorter than 500 milliseconds were usually far below the average values. The mean percentage differences were not significantly different between methods using interval differences of less than 5% and less than 10% for 3-beat analysis (2.83% vs. 2.97%, p=0.269). Moreover, it is relatively easy to obtain beats with interval difference less than 10%. The median numbers of beats required finding 3 beats with inter-beat variability of less than 10% and less than 5% were 9 and 16, respectively.
Conclusions: Averaging 3 beats with R-R interval difference less than 10% and cycle lengths longer than 500 milliseconds can be applied to accurately estimate Doppler-derived aortic flow for patients with AF.

並列關鍵字

Atrial fibrillation ； Left ventricle ； Stroke volume ； Systole ； Ventricular function