Left atrial emptying fraction correlation with vascular pedicle width in patients with normal systolic function.
OBJECTIVE
To determine the correlation and diagnostic utility of impaired left atrial emptying fraction, an indicator of diastolic dysfunction, with raised intravascular volume determined by vascular pedicle width on upright postero-anterior chest roentgenogram.


METHODS
Cohort study.


METHODS
Department of Medicine, King Abdulaziz National Guard Hospital, Alhasa, Saudi Arabia from October till December 2002.


METHODS
Thirty-two out of 56 patients with normal systolic function (ejection fraction >50%) on echocardiogram were included in the study. Left atrial dimensions were measured at the end of left ventricular diastole (LADed) and systole (LADes) on M-mode tracing. Left atrial emptying fraction (LAEF) was calculated by dividing LADed by LADes. Ratio of peak early diastolic velocity (E/A) to peak late diastolic velocity, isovolemic relaxation time (IVRT) and deceleration time of E-wave (DT) were also recorded on transmitral Doppler signal. Postero-anterior views of chest X-rays done within 48 hours of echocardiogram were studied for the measurement of vascular pedicle width (VPW) and cardiothoracic ratio (CTR). Univariate and multiple regression analysis were performed to identify possible predictors of VPW. Receiver operator curves were constructed to see diagnostic utility of impaired LAEF for raised intravascular volume measured by VPW.


RESULTS
Mean age for the patients was 58.56 +/- 17 years. There were 15 females (46.9%) and 17 males (54.1%). LADes, LADed, LAEF and DT were 2.89 +/- 0.63 cm, 3.81 +/- 0.53 cm, 0.75 +/- 0.10 and 202 +/- 49.9 msec respectively. VPW and CTR were 55.81 +/- 10.2 mm and 0.54 +/- 0.08. Significant independent predictors of VPW on univariate regression analysis were entered into multiple regression models, which revealed LAEF and DT as the only predictors of VPW. The final regression equation was VPW = 15.43 + 35.7 (LAEF) + 0.06 (DT), R2 = 0.35, p = 0.0008. LAEF > 0.75 had a sensitivity of 74% and specificity of 94% for diagnosing raised intravascular volume defined as VPW > 53 mm.


CONCLUSIONS
LAEF > 0.75 is a reliable indicator of intravascular volume expansion in patients with normal systolic function signifying diastolic dysfunction and activation of salt and water retaining mechanisms.
Iqbal
Mobeen
M
Department of Pulmonology, King Abdulaziz National Guard Hospital, Alhasa, Kingdom of Saudi Arabia. iqmob@yahoo.com
Ahmed
Raees
R
Al Balas
Hassan
H
Gharard
Salah Uddin
SU
Alotaibi
Fahad D
FD
D016279:Atrial Function, Left / Q000502:physiology*; D004452:Echocardiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013599:Systole / Q000502:physiology