Overview

This prospective multicenter registry study aims to detect the serial changes in ventriculo-ventricular conduction times according to cardiac-resynchronization therapy response.

Eligibility

Inclusion Criteria:

• meeting the current ESC or ACCF/AHA/HRS Class I or Class IIa indications for cardiac-resynchronization (CRT) implant

Exclusion Criteria:

• Myocardial infarction, unstable angina within 40 days prior the enrollment
• Recent cardiac revascularization in the 4 weeks prior to the enrollment or planned for the 3 months following
• Cerebrovascular accident (CVA) or transient ischemic attack (TIA) in the 3 months prior to the enrollment
• Primary valvular disease requiring surgical correction
• Pregnant or are planning during the duration of the investigation
• Status 1 candidate for cardiac transplantation or consideration for transplantation over the next 12 months
• Post-cardiac transplantation
• Life expectancy < 12 months
• Currently participating in any other clinical investigation except for observational registry