Heart failure is a progressive disease that decreases the pumping action of the heart. This may cause a backup of fluid in the heart and may result in heart beat changes. Using a medical device like a pacemaker or a defibrillator can help the heart to pump in regular beats. However, not all patients do better with a device. Currently, there is not a way to identify which patients will benefit from the device. The purpose of this study is to determine if using medical tests, Echocardiogram, can help in predicting which patients will improve. The types of patients needed for this study are those who have been diagnosed with moderate or severe heart failure.

Inclusion Criteria:

• Moderate to severe heart failure

  • Ejection Fraction ( measurement of blood pumped out of the heart) less than 35%
  • Wide (greater than 130 milliseconds) QRS duration for US patients only.
  • May include patients with less than 130 millisecond QRS duration if they have mechanical dyssynochrony (uncoordinated heart contractions) in Europe.
  • All patients enrolled should be stable on medications that include at least an ACE inhibitor or Angiotensin Receptor Blocker (ARB) and at optimal level for at least one month prior to surgery

Exclusion Criteria:

• Patients that are not eligible for this study are those that have a mechanical right heart valve or are experiencing the following medical conditions within the last 3 months:

  • Chest pain / unstable angina
  • Acute heart attack
  • Chronic or permanent atrial arrhythmias such as atrial fibrillation
  • Contrary artery bypass graft (CABG)
  • Percutaneous transluminal coronary angioplasty (PTCA)
  • Patients who have had intermittent or continuous Inotropic drug therapy are not eligible for this study.
  • Patients who have had heart transplant or a prior Cardiac Resynchronization Therapy device are not eligible for this study.
  • Patients who are pregnant or are of child-bearing potential are not on a form of birth control may not participate in this study.