Mechanical and Electrical Myocardial Support

Similar to mechanical circulatory devices, cardiopulmonary resuscitation (CPR) delivers oxygen and blood to vital organs. High-quality CPR can provide sufficient coronary blood flow, cerebral blood flow, and oxygen to attain return of spontaneous circulation or as a bridge to extracorporeal life support. For years, extracorporeal membrane oxygenation (ECMO) was the only readily accessible form of mechanical circulatory support in children for both short-term and medium-term support. ECMO is a temporary support strategy used as a bridge to transplant or bridge to recovery. The use of ECMO beyond 10–14 days is often limited by a number of complications including stroke, bleeding, and infection. Alternative mechanical circulatory support devices remained limited in children smaller than adult size until 2000 when the Berlin Heart EXCOR™ pulsatile ventricular assist device (VAD) was utilized in a pediatric patient. With further VAD technologic advancements, VAD use in infants and children continues to increase. VADs can be used as long-term devices and are primarily used as a bridge to transplant, providing time to make a decision or to permit recovery, and infrequently as a destination (i.e., final form) therapy. There are significant survival benefits of long-term VAD support over ECMO support for patients awaiting heart transplant. Controversy exists regarding the best mode of mechanical circulatory support if the anticipated support duration is less than 2 weeks. Most institutions will consider transition from ECMO to a VAD within 7–10 days of support; however, this decision is often based on the patient’s potential for recovery and anticipated duration of support. Arrhythmias may lead to impaired oxygen delivery and blood flow. A pacemaker is an electrical device that can be used to restore the cardiac rhythm to optimize oxygen delivery and blood flow. In this chapter, we review the various forms of mechanical and electrical myocardial support utilized to improve oxygen delivery and blood flow.