Efficacy and Safety of Ivabradine to Reduce Heart Rate Prior to Coronary CT-angiography in Advanced Heart Failure: Comparison With β-Blocker

Dyspnea

Shortness of breath, or "dyspnea", is the most famous symptom of left ventricular failure. It typically appears during strenuous activities, and progresses to ordinary activities, less than ordinary activities and ultimately resting state. The severity is categorized as above (FC 1 to 4)

Time frame: 30 minutes before and after coronary CT angiography and 6 months later

Functional calss

Heart Failure severity has been classified according to New York Heart Association (NYHA) to: * Class I: No limitation of physical activity. Ordinary physical activity does not cause symptoms of HF. * Class II: Slight limitation of physical activity. Comfortable at rest, but ordinary physical activity results in symptoms of HF. * Class III: Marked limitation of physical activity. Comfortable at rest, but less than ordinary activity causes symptoms of HF. * Class IV: Unable to perform any physical activity without symptoms of HF, or symptoms of HF at rest.

Time frame: 30 minutes before and after coronary CT angiography and 6 months later

Blood pressure, systolic and diastolic

The amount of blood pressure measured by sphygmomanometer

Time frame: 30 minutes before and after coronary CT angiography and 6 months later

Sleep quality

The rate of disturbed sleep measured as better than before, Worse than before, and No change There are no standard classification for severity of this symptom. In our study, we measure this symptom as : * Better than before (1) * Worse than before (2) * No change (0)

Time frame: Before CT angiography and 6 months later

Appetite

The rate of changing in appetite level measured as better than before, Worse than before, and No change Loss of appetite is a common symptom of heart failure. There are no standard classification for severity of this symptom. In our study, we measure this symptom as : * Better than before (1) * Worse than before (2) * No change (0)

Time frame: Before CT angiography and 6 months later

Prolonged bradycardia

Persistence of Bradycardia more than 6 hours is called prolonged bradycardia.

Time frame: 30 minutes before and after coronary CT angiography

Hypotension

Systolic less than 80 mm Hg

Time frame: 30 minutes before and after coronary CT angiography