End-diastolic flow reversal limits the efficacy of pediatric intra-aortic balloon pump counterpulsation

Abstract

OBJECTIVE Counterpulsation with an intraaortic balloon pump (IABP) has not achieved the same successes or clinical use in pediatric patients as in adults. In a pediatric animal model, IABP efficacy was investigated to determine whether IABP timing with a high-fidelity blood pressure signal may improve counterpulsation therapy versus a low-fidelity signal. METHODS In Yorkshire piglets (n=19, 13.0±0.5 kg) with coronary ligation-induced acute ischemic left ventricular failure, pediatric IABPs (5 or 7cc) were placed in the descending thoracic aorta. Inflation and deflation were timed with traditional criteria from low-fidelity (fluid-filled) and high-fidelity (micromanometer) blood pressure signals during 1:1 support. Aortic, carotid, and coronary hemodynamics were measured with pressure and flow transducers. Myocardial oxygen consumption was calculated from coronary sinus and arterial blood samples. Left ventricular myocardial blood flow and end-organ blood flow were measured with microspheres. RESULTS Despite significant suprasystolic diastolic augmentation and afterload reduction at heart rates of 105±3bmp, left ventricular myocardial blood flow, myocardial oxygen consumption, the myocardial oxygen supply/demand relationship, cardiac output, and end-organ blood flow did not change. Statistically significant end-diastolic coronary, carotid, and aortic flow reversal occurred with IABP deflation. Inflation and deflation timed with a high-fidelity versus low-fidelity signal did not attenuate systemic flow reversal or improve the myocardial oxygen supply/demand relationship. CONCLUSIONS Systemic end-diastolic flow reversal limited counterpulsation efficacy in a pediatric model of acute left ventricular failure. Adjustment of IABP inflation and deflation timing with traditional criteria and a high-fidelity blood pressure waveform did not improve IABP efficacy or attenuate flow reversal. End-diastolic flow reversal may limit the efficacy of IABP counterpulsation therapy in pediatric patients with traditional timing criteria. Investigation of alternative deflation timing strategies is warranted.

Intra‐Aortic Balloon Pump Malposition Reduces Visceral Artery Perfusion in an Acute Animal Model

“…Bartoli and colleagues made similar findings regarding flow reversal in another study. They investigated the efficacy of IABP in pediatric patients, which may be limited by the end‐diastolic flow reversal of the IABP . The results of both studies combined with our findings reinforce our hypothesis that an IABP overlapping the ostia of a visceral artery leads to ischemia, possibly by inducing a nonocclusive mesenteric ischemia .…”

Mechanical Circulatory Support Devices for Pediatric Patients With Congenital Heart Disease

“…. The synchronization challenge has led researchers to develop better timing strategies . Further obstacles in IABP usage are related to the anatomy of the pediatric patient, such as in cases of isolated RV failure or biventricular failure .…”

“…IABP use‐related concerns in adult patients have been related to a suction phenomenon due to reduction in end diastolic blood pressure that causes a reversal of blood flow in the main branch arteries. This effect in pediatric patients is still under investigation .…”

Hybrid Continuous‐Flow Total Artificial Heart

“…More than 15% of the patients on the donor waiting list will die due primarily to the lack of a sufficient number of donor hearts. This limitation and the increasing need for biventricular support necessitate the development of therapeutic alternatives, such as total artificial hearts (TAHs) and improved ventricular assist devices (VADs) .…”