Patients with diagnosis of coronary artery disease (CAD)
* Patients present with the symptoms of stable angina after withdrawn from other antianginal drugs and given the required background therapy for at least 7 days will be qualified for entering this study and performing 1st ETT qualifying test
* Patients developed exercise-induced ECG ischemiai during two qualifying exercise treadmill testsii.
* Willing and able to provide a written informed consent
You may not be if
• Factors that might compromise ECG or ETT interpretation
* Patients with resting ST-segment depression ≥ 1mm in any lead
* Left bundle-branch block
* Patients implanted with pacemaker
* Patients under Digitalis therapy
* Patients with family history of (or congenital) long QT syndrome
* Patients with congenital heart disease
* Patients with uncorrected valvular heart disease
* Patients with unstable angina, or MI, or coronary revascularization procedure ≤ 2 months prior enter this study
* Female who is pregnant/lactating or planning to be pregnant, or female of childbearing potential\* who is not using medically recognized method of contraception
* \*Other than those who have been surgically sterilized (defined as having undergone hysterectomy or bilateral oophorectomy or bilateral salpingectomy; tubal ligation alone is not considered sufficient) or one year post-menopausal.
• Patients are under any one of the following conditions:
* New York Heart Association (NYHA) Class III or Class IV congestive heart failure (CHF)
* QTc \> 450 msec at screening
* Active myocarditis, pericarditis, hypertrophic cardiomyopathy
* Use of any investigational product ≤ 4 weeks prior to screening
* Patients with severe hepatic disease (e.g., liver cirrhosis)
* Patients with impaired renal function (defined as serum Cr \>1.5 mg/dl)
* Patients with any condition or disease which is considered not suitable for this study by investigator
