22. Denervated (Transplanted) Heart
Definition
Denervated, or transplanted, heart is not a disease and is something of a misnomer. The denervated heart is a heart that has been donated and transplanted. In this case, “denervated” means the transplanted heart is not under the control of the recipient’s autonomic nervous system and brain; instead, the heart rate is determined completely by the intrinsic rate(s) of the allograft heart. The atrioventricular node is predominately the rate controller for this heart because the sinus node is often irreparably damaged in the transplant process.
Incidence
About 1% of the population with end-stage congestive heart failure receive a donor heart.
Etiology
Transplants are reserved for patients with end-stage congestive heart failure who have a prognosis of less than 1 year to survive without replacement of the damaged heart.
Indications for Cardiac Transplant
• Ability to comply with follow-up care
• Age <65 years
• Congenital heart disease
• Dilated cardiomyopathy
• Ejection fraction <25%
• Intractable angina
• Ischemic cardiomyopathy
• Malignant cardiac dysrhythmias
• Pulmonary vascular resistance <2 Wood units
Contraindications to Cardiac Transplant