Detection of prolonged regional myocardial systolic dysfunction after exercise-induced myocardial ischemia by strain echocardiography with high frame rate tissue Doppler echocardiography.
BACKGROUND
Strain echocardiography has enabled quantification of regional myocardial systolic function objectively and is less influenced by tethering effects and cardiac translational artifact than Doppler tissue imaging. Although strain echocardiography has been applied for the detection of inducible ischemia during dobutamine stress, it has not been fully applied to exercise stress echocardiography (ESE) because of technical difficulties. Prolonged myocardial systolic dysfunction after exercise-induced ischemia has been shown previously. Thus, we designed this study to evaluate whether the myocardial strain analysis can detect myocardial ischemia by the assessment of prolonged regional left ventricular (LV) dysfunction in ESE.


METHODS
We performed ESE with myocardial strain imaging system in 20 consecutive patients who had exercise Tl-201 single photon emission computed tomography (SPECT). Myocardial strain curves were obtained at six segments in mid LV walls from the apical approach before and 5 min after ESE. We measured the duration from the R wave in the electrocardiogram to the timing of peak systolic strain corrected by the square root of the RR interval (TPSc). We finally calculated the differences of TPSc (ΔTPSc) before ESE and 5 min after ESE. The results were compared with SPECT as a reference standard.


RESULTS
A receiver operating characteristic curve demonstrated that a ΔTPSc cutoff value of 70 ms had a sensitivity of 80% and a specificity of 84% for the detection of myocardial ischemia.


CONCLUSIONS
Prolonged regional LV systolic dysfunction assessed by ESE with strain analysis was useful for the detection of myocardial ischemia.
Department of Internal Medicine and Cardiology, Osaka City University School of Medicine, 1-4-3 Asahimachi, Abeno-ku, Osaka, 545-8585, Japan.
Yasuhiro
Y
Takagi
Department of Internal Medicine and Cardiology, Osaka City University School of Medicine, 1-4-3 Asahimachi, Abeno-ku, Osaka, 545-8585, Japan. take-hzm@wb3.so-net.ne.jp.
Takeshi
T
Hozumi
Department of Internal Medicine and Cardiology, Osaka City University School of Medicine, 1-4-3 Asahimachi, Abeno-ku, Osaka, 545-8585, Japan.
Yasuhiko
Y
Takemoto
Department of Internal Medicine and Cardiology, Osaka City University School of Medicine, 1-4-3 Asahimachi, Abeno-ku, Osaka, 545-8585, Japan.
Kazuaki
K
Negishi
Department of Internal Medicine and Cardiology, Osaka City University School of Medicine, 1-4-3 Asahimachi, Abeno-ku, Osaka, 545-8585, Japan.
Zhu
Z
Hong
Central Clinical Laboratory, Osaka City University Medical School, Osaka, Japan.
Kohji
K
Abo
Central Clinical Laboratory, Osaka City University Medical School, Osaka, Japan.
Kazuya
K
Fujioka
Central Clinical Laboratory, Osaka City University Medical School, Osaka, Japan.
Mitsuru
M
Nakao
Department of Internal Medicine and Cardiology, Osaka City University School of Medicine, 1-4-3 Asahimachi, Abeno-ku, Osaka, 545-8585, Japan.
Ryo
R
Otsuka
Department of Internal Medicine and Cardiology, Osaka City University School of Medicine, 1-4-3 Asahimachi, Abeno-ku, Osaka, 545-8585, Japan.
Kenichi
K
Sugioka
Department of Internal Medicine and Cardiology, Osaka City University School of Medicine, 1-4-3 Asahimachi, Abeno-ku, Osaka, 545-8585, Japan.
Yoshiki
Y
Kobayashi
Department of Internal Medicine and Cardiology, Osaka City University School of Medicine, 1-4-3 Asahimachi, Abeno-ku, Osaka, 545-8585, Japan.
Hiroyuki
H
Yamagishi
Department of Internal Medicine and Cardiology, Osaka City University School of Medicine, 1-4-3 Asahimachi, Abeno-ku, Osaka, 545-8585, Japan.
Minoru
M
Yoshiyama
Department of Internal Medicine and Cardiology, Osaka City University School of Medicine, 1-4-3 Asahimachi, Abeno-ku, Osaka, 545-8585, Japan.
Junichi
J
Yoshikawa
Ischemic heart disease; Myocardial strain analysis; Stress echocardiography; Tissue Doppler echocardiography