investigator left the institution

The investigators hypothesize that the relation between mechanical and hemodynamic left ventricular dyssynchrony might better predict response to Cardiac Resynchronization Device(CRT) than currently existing echo indices.

Cardiac resynchronization therapy is emerging to be a highly effective treatment option for selected patients with symptomatic congestive heart failure on optimal medical therapy and evidence of left ventricular (LV) conduction delay and contraction dyssynchrony. It can improve quality of life and results in better survival in this selected group of patients. However, patients have different responses to CRT, and up to 30% of those implanted show no response at all. Ongoing trials, whether prospective or retrospective, have been trying to define best predictors of response to CRT and to measure ventricular dyssynchrony. Despite this, no single echo criterion to date can predict successful CRT over current guidelines.

In this study, we propose to compare LV muscle mechanical dyssynchrony assessment by speckle tracking to hemodynamic dyssynchrony assessment by 4D segmental ejection fraction (EF), a novel modality brought recently by University of Missouri Echocardiography laboratory.

Inclusion Criteria:

• Cardiac Resynchronization Therapy(CRT) device implanted in the last 5 years.

Exclusion Criteria:

• Acute decompensated congestive heart failure.
• chronic permanent atrial fibrillation

Patients followed in cardiology clinic will be included.