Work

P5.21 Early Iabp Inflation Suppresses Left Ventricular Function as Indicated by Wave Intensity Analysis

Year: 2013

Type: article

Abstract: Background: Timing errors during Intra-Aortic Balloon Pump (IABP) support can be detrimental when interfering with cardiac function. In vivo hemodynamics and left ventricular (LV) function were monitored during premature IAB inflation, and the associated mechanisms investigated with Wave Intensity Analysis. Methods: Six healthy, anaesthetised, open-chest sheep received IABP support with frequency 1:3 (n=3) and 1:1 (n=3). Aortic (Qao) and coronary (Qcor) flow, and aortic (Pao) and left ventricular (PLV) pressure were recorded simultaneously with and without IABP. Early inflation (EI) was triggered -91±9ms (1:3) and −105±36ms (1:1) before the incisura. Integrating systolic Qao and subsequent negative Qao yielded stroke volume (SV) and backflow, respectively. Forward expansion (FEW) and forward compression (FCW) wave energies, generated by the slowing of LV contraction preceding inflation and by early LV ejection following deflation, respectively, were obtained. Results are mean±standard deviation. Results: EI increased diastolic (d) Qcor in 1:3 but not in 1:1. EI appears to be detrimental for LV function, as indicated by substantial FEW reduction in both frequencies, concurring with increased backflow. Systolic (s) Pao and PLV did not corroborate suppressed LV function, but SV tended to decrease at 1:3 in the systole preceding EI. FCW reduction was also observed. IABP on IABP off 1:3 1:1 1:3 1:1 FEW (J/m2) 0.026±0.015* 0.031±0.017* 0.059±0.026 0.073±0.026 FCW (J/m2) 0.117±0.044* 0.086±0.051* 0.147±0.048 0.087±0.060 SV (ml) 67±16 78±28 71±17 77±32 Backflow (ml) 3.0±0.3* 4.410.9* 1.8±0.3 3.1±0.4 dQcor (ml/min) 182±17* 148±6* 150±17 149±36 sPLV (mmHg) 67±10 69±5* 67±13 76±7 sPao (mmHg) 71±11 73±8* 71±13 81±8 *P<0.05 comparing EI to off, #P<0.05 comparing 1:1 to 1:3. Conclusion: With the aortic valve still open during EI, the IABP may displace blood directly into the LV and interrupt late LV ejection, as demonstrated by reduced FEW energy. Coronary perfusion is not affected by this mechanism. Concurrent reduction in FCW energy, albeit not exclusively caused by EI, further indicates compromised LV function.

Source: Artery Research

DOI: 10.1016/j.artres.2013.10.169

Authors: C. Kolyva, G.M. Pantalos, J.R. Pepper, A.W. Khir

Institutions: Brunel University of London, Cardiovascular Innovation Institute, Royal Brompton Hospital

Language: English

Topic: Mechanical Circulatory Support Devices

Subfield: Biomedical Engineering

Field: Engineering

Domain: Physical Sciences

SDG: Good health and well-being

Open Access status: hybrid

Estimated APC paid: $1,790