title: Left ventricular dyssynchrony in patients with moderate coronary stenosis and border line fractional flow reserve.
abstract: The cutoff values of fractional flow reserve (FFR) to detect physiological myocardial ischemia are still controversial. Some studies have reported that left ventricular (LV) dyssynchrony occurs in patients with coronary artery disease (CAD). The purpose of this study was to investigate LV dyssynchrony in patients with moderate coronary stenosis and borderline FFR, using stress electrocardiographically-gated myocardial perfusion single-photon emission computed tomography (SPECT). The study population comprised 10 patients with moderate (50-75% diameter) stenosis and an FFR in the range 0.75-0.90, who were compared to 10 control subjects. All underwent stress myocardial (99m)Tc-sestamibi (MIBI) or tetrofosmin SPECT imaging. The regional time to end systole (TES), time to peak ejection (TPE), and time to peak filling (TPF) were obtained as indexes of perfusion and function, using gated SPECT (pFAST) in combination with Cardio Gated SPECT Regional Assessment for LV Function (cardioGRAF). The dyssynchrony index (DI) was also calculated. The DI of post-stress TES was significantly greater than that of rest in patients with moderate CAD (4.8 ± 2.8 vs. 2.7 ± 1.5, P = 0.01), but there were no significant differences in the control subjects (3.0 ± 1.7 vs. 2.9 ± 1.9, P = 0.99). There were no significant differences in TPE and TPF between the groups. In conclusion, LV dyssynchrony may occur after stress in patients with coronary stenosis and borderline FFR, even without a significant reduction in perfusion.
authors: Department of Cardiology, Nagoya University Graduate School of Medicine, Nagoya, Japan ; Division of Cardiology, Ogaki Municipal Hospital, Ogaki, Japan.
authors: Yohei
authors: Y
authors: Shibata
authors: Division of Cardiology, Ogaki Municipal Hospital, Ogaki, Japan.
authors: Takahito
authors: T
authors: Sone
authors: Division of Cardiology, Ogaki Municipal Hospital, Ogaki, Japan.
authors: Hideyuki
authors: H
authors: Tsuboi
authors: Department of Cardiology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors: Satoshi
authors: S
authors: Isobe
authors: Department of Cardiology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors: Hideki
authors: H
authors: Ishii
authors: Department of Cardiology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors: Susumu
authors: S
authors: Suzuki
authors: Department of Cardiology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors: Mutsuharu
authors: M
authors: Hayashi
authors: Department of Cardiology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors: Toyoaki
authors: T
authors: Murohara
keywords: fractional flow reserve; left ventricular dyssynchrony; stress electrocardiographically-gated myocardial perfusion single-photon emission computed tomography