The purpose of this study is to assess the effects of Chinese medicine Shansong Yangxin capsule for sinus bradycardia complicated with ventricular premature beats.

Premature ventricular contractions is one of the most common symptomatic arrhythmia. Antiarrhythmia drugs for premature ventricular contractions, such as beta-blockers and sodium channel blockers, can cause bradycardia. For sinus bradycardia patients complicated with premature ventricular contractions, it's hard for doctors to make decision. The purpose of the study is to assess the effects of Chinese medicine Shansong Yangxin capsule for sinus bradycardia complicated with ventricular premature beats, which based on the numbers of premature ventricular contractions and average hear rate in 24-hour ambulatory electrocardiogram (ECG) after 8 weeks treatment as the primary endpoint of the study. Secondary endpoints are evaluation of the Shensong Yangxin capsule on quality of life. This study is a randomized, double-blind, placebo controlled, multi-center trial. Sinus bradycardia patients(average heart rate 45-59 beat per minute) associated with premature ventricular contractions (PVC number >10000 / 24h), are involved in the study. Patients are randomly assigned into Shensong Yangxin capsule group or placebo group, with the capsule administration of 4 granules t.i.d.for 8 weeks. 24-hour ambulatory ECG, are observed at baseline,4 weeks and 8 weeks after the intervention. The primary outcomes are the numbers of premature ventricular contractions and average heat rate in 24-hour ambulatory ECG, and the secondary outcomes is Minnesota living with heart failure questionnaire (MLHFQ).

Inclusion Criteria:

• 18 Years to 70 Years old
• Documented sinus bradycardia with average heart rate at 45-59 by 24hours ambulatory EKG
• Ventricular premature beats: >1000 beats/24 hours

Exclusion Criteria:

• Younger than 18 years or older than 75 years
• Symptomatic sinus arrest >3 seconds or high degree atrioventricular block indicated for pacemaker
• Subject suffered from acute coronary syndrome in last three months (Acute myocardial infarction of ST segment elevation and non ST segment elevation, unstable angina
• To be complicated with persistent atrial fibrillation, or paroxysmal atrial fibrillation >5% during 24hrs ambulatory EKG or acute myocarditis
• To be complicated with ventricular fibrillation, torsion type ventricular heartbeat rate, sustained ventricular tachycardia, or non sustained ventricular tachycardia with rapid ventricular rate and hemodynamic disorders
• Sinus heart rate less than 45 beats/minutes and needs to receive the pacemaker or has received pacemaker, or with ICD,CRTP/D