Cardiac Resynchronization and Iodine Meta-Iodobenzylguanidine (MIBG) Imaging


About this study

Congestive heart failure (CHF) affects nearly 5 million Americans and claims more than 300,000 lives annually. A primary pathophysiologic mechanism in this deadly syndrome is an abnormally enhanced sympathetic nervous system that results in profound peripheral vasoconstriction, attenuated cardiovascular reflexes, higher susceptibility to ventricular arrhythmias, and sudden cardiac death. The reduction in mortality and morbidity in CHF by pharmacologic neurohumoral antagonists such as beta-receptor inhibitor and angiotensin II-converting enzyme (ACE) inhibitor has taught us that regulation of the impaired neurohumoral axis is important for improving clinical outcome. In addition, an emerging nonpharmacologic approach, cardiac resynchronization therapy (CRT), has shown promise for improving symptoms and quality of life in patients with New York Heart Association (NYHA) functional class III or IV and intraventricular conduction delay. However, despite significant advances in CHF treatment in the past two decades, a gap remains between clinical outcome and the mechanisms of the protective effects of these modern therapies.

CHF is associated with increased concentrations of circulating norepinephrine (NE), down-regulation of adrenergic nerve terminals, and abnormal NE reuptake. The suppression of cardiac sympathetic nerve endings could be reversed by CRT, a novel anti-heart failure therapy, by rebalance cardiac sympathetic activity, and improve cardiac function in patients with heart failure.

Participation eligibility

Participant eligibility includes age, gender, type and stage of disease, and previous treatments or health concerns. Guidelines differ from study to study, and identify who can or cannot participate. There is no guarantee that every individual who qualifies and wants to participate in a trial will be enrolled. Contact the study team to discuss study eligibility and potential participation.

Inclusion criteria:

Indications for Biv-ICD implantation

  1. Chronic moderate to severe CHF (NYHA class II or IV)
  2. Left ventricular ejection fraction (LVEF) of 35% or less
  3. QRS duration of 120 ms or more
  4. On optimized anti-heart failure medical regimen
  5. Meet one of the following indications for ICD
    • Survivors of cardiac arrest due to ventricular fibrillation (VF) or ventricular tachycardia (VT) or spontaneous sustained VT
    • Nonsustained VT with coronary disease, prior myocardial infarction, LVEF 35% or less, and inducible VF or sustained VT at electrophysiologic study
    • LVEF of 30% or less with severe coronary artery disease

Exclusion criteria:

  1. Patient condition is unstable
  2. Patient is unable to give informed consent
  3. Not feasible for patient to be followed at Mayo Clinic
  4. Female in pregnancy and breast feeding

Participating Mayo Clinic locations

Study statuses change often. Please contact the study team for the most up-to-date information regarding possible participation.

Mayo Clinic Location Status

Rochester, Minn.

Mayo Clinic principal investigator

Yong-Mei Cha, M.D.

Closed for enrollment

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