Echocardiography Guided Cardiac Resynchronization Therapy (EchoCRT)

Inclusion Criteria:

• Men and women 18 years of age or older.
• Understand the nature of the procedure.
• Give written informed consent.
• Willing and able to complete all testing required by the clinical protocol.
• Indication for an implantable cardioverter defibrillator (ICD).
• NYHA class III-IV within the last three months prior to enrollment and at baseline (at baseline only: also Stage C according to ACC/AHA guidelines).
• Stable optimal pharmacologic therapy for HF.
• An ejection fraction ≤ 35% within one year prior to enrollment and confirmed on the baseline echocardiogram.
• Increased left ventricular dimension, defined as LVEDD ≥ 55 mm.
• Resting QRS duration < 130 ms evidenced by a historical 12-lead ECG prior to enrollment and at baseline.

• Ventricular dyssynchrony assessed by echocardiography locally and confirmed by the echo core lab. One of the two following criteria has to be present to include the subject in the study:

  • Intra-left ventricular dyssynchrony measured by color Tissue Doppler Imaging (TDI) with an opposing wall delay of ≥ 80 ms in the 4-chamber or apical long-axis view.
  • Speckle-tracking radial strain septal-posterior wall delay ≥ 130 ms.

Exclusion Criteria:

• Implanted pacemaker or defibrillator with >10% ventricular pacing, as demonstrated by device statistics averaged over at least the last three months prior to enrollment.
• Women who are pregnant, lactating, or planning to become pregnant during the course of the trial.
• Bradycardia pacing indication.
• Surgically correctable primary valvular heart disease, i.e. aortic stenosis, torn cordae, or flail segment.
• Coronary artery bypass graft surgery or percutaneous coronary intervention (balloon and/or stent angioplasty) within the past 3 months prior to enrollment.
• Enzyme-positive myocardial infarction within the past 3 months prior to enrollment.
• Angiographic evidence of coronary disease, candidates for coronary revascularization likely to undergo coronary artery bypass graft surgery or percutaneous coronary intervention in the next 3 months.
• Irreversible brain damage from preexisting cerebral disease.
• Reversible non-ischemic cardiomyopathy such as acute viral myocarditis.
• Permanent second or third degree heart block.
• Chagas disease.
• Persistent or paroxysmal atrial fibrillation within one month prior to enrollment.
• Expected to receive heart transplantation within six months.
• Current inotropic therapy.
• Acutely decompensated heart failure.
• Contrast dye allergy and unable or unwilling to undergo pretreatment with steroids and/or diphenhydramine.
• Life expectancy of less than six months.
• Presence of any disease, other than the subject's cardiac disease associated with a reduced likelihood of survival for the duration of the trial, (e.g. cancer).
• Significant renal insufficiency defined as a serum creatinine > 2.5 mg/dL (> 221 µmol/L) within the last four weeks prior to enrollment..
• Liver failure, defined as three times the upper limit of normal for aminotransferases.
• Participation in any other clinical trial.
• Unable to return for follow-up visits due to distance from the clinic.
• Do not anticipate being a resident of the area for the scheduled duration of the trial.