Corrected Left Ventricular Electrical Delay Predicting Response to Cardiac Resynchronization Therapy

Study Overview
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Brief Summary
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Cardiac resynchronization therapy (CRT) is a well-established treatment for patients with severe systolic heart failure (HF) and ventricular desynchronization. Despite the consistently observed structural and functional improvements as well as reductions in HF events and mortality in large multicenter randomized trials, 30% patients remain classified as nonresponders. Present evidences showed that QRS duration was the most effective parameter to predict responsivity of CRT in patients with severe HF. But some studies showed that QRS duration could be influenced by obesity and gender. Accordingly, the simple QRS interval width of body surface electrocardiograph should not be the most satisfactory parameter for screening patients suitable for CRT. Recent study showed that left ventricular electrical delay, as measured by the time from the onset of QRS to the LV electrogram peak (QLV), predicted CRT response. At long QLV intervals, atrioventricular optimization (AVO) can increase the likelihood of structural response to CRT. However, it is unclear whether it is suitable for Chinese patients. The investigators would like to validate this relation in a Chinese population and explore if a corrected QLV might do better to predict the responsivity of CRT.

Official Title
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A Prospective Clinical Trial of Corrected Left Ventricular Electrical Delay Predicting Response to Cardiac Resynchronization Therapy in Chinese With Heart Failure

Conditions
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Chronic Heart Failure, Cardiac Resynchronization Therapy

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: •More than 18 Years Informed consent signed NYHA class ≥ II, an ejection fraction of ≤ 0.35, QRS duration of ≥ 150 milliseconds with Non-LBBB) or ≥ 120 milliseconds with LBBB, who treated with CRT The Estimated survival time was more than one year sinus rhythm, pacemaker independent Exclusion Criteria: •NYHA class I symptoms Severe liver or kidney dysfunction Valvular heart disease Pregnancy or lactation women percutaneous coronary intervention (PCI) or cardiac artery bypass graft (CABG) within 3 month Have malignant tumors and the Estimated survival time was less than one year an enzyme-positive myocardial infarction within 3 months before enrollment, or atrial fibrillation any reasons cannot complete follow-up; Or researchers think that don't suit to be included in the research of other conditions

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| heart failure<br>heart failure patients with CRT | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Left Ventricular End Systolic Volume (LVESV) | change in LVESV | baseline and 6 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| New York Heart Association (NYHA) | change in NYHA | baseline and 6 months | 
| left ventricular ejection fraction (LVEF) | change in LVEF | baseline and 6 months |