Increase in coronary blood flow by intra-aortic balloon counterpulsation in a porcine model of myocardial reperfusion.
BACKGROUND
Studies of the IABP have reported variable effects on coronary blood flow (CBF). The purpose of the present study was to measure the changes in coronary blood flow induced by intra-aortic balloon pump (IABP) counterpulsation in normal and reperfused porcine myocardium.


METHODS
A 30-ml IABP was placed in the descending aorta of 6 open-chest pigs. Each pig underwent occlusion of the mid-left anterior descending (LAD) coronary artery for 1 h, followed by reperfusion for 2 h. The effects of IABP support on systolic aortic pressure (SAP) and aortic end-diastolic pressure were recorded. The mean CBF, distal to the LAD occlusion site was measured at baseline and during reperfusion, with and without IABP counterpulsation.


RESULTS
The IABP decreased SAP and aortic end-diastolic pressure in normal and reperfused myocardium, and maintained a peak aortic diastolic augmentation at the level of SAP. In normal myocardium, the IABP decreased mean CBF by 8.4+/-2.2% (p<0.001). At 2, 15, 30, 60, 90 and 120 min of reperfusion, the IABP increased mean CBF by 11.5+/-6.8%, 8.0+/-7.0%, 11.2+/-6.9%, 12.4+/-12.9%, 23.5+/-9.9% and 8.9+/-6.9%, of the corresponding value without the assistance of the IABP (all p<0.05).


CONCLUSIONS
In the normal heart, IABP counterpulsation decreased CBF, probably because of a decrease in myocardial oxygen demand from a decreased afterload. During reperfusion the IABP increased CBF, suggesting that it might effectively mitigate the no-reflow phenomenon.
Bonios
Michael J
MJ
3rd Department of Cardiology, University of Athens School of Medicine, Athens, Greece.
Pierrakos
Charalampos N
CN
Argiriou
Michael
M
Dalianis
Argirios
A
Terrovitis
John V
JV
Dolou
Paraskevi
P
Drakos
Stavros G
SG
Koudoumas
Dimitrios
D
Charitos
Christos E
CE
Anastasiou-Nana
Maria I
MI
D000818:Animals; D001794:Blood Pressure / Q000502:physiology; D003326:Coronary Circulation / Q000502:physiology*; D003971:Diastole / Q000502:physiology; D004195:Disease Models, Animal; D007423:Intra-Aortic Balloon Pumping; D015425:Myocardial Reperfusion / Q000379:methods*; D015428:Myocardial Reperfusion Injury / Q000378:metabolism / Q000503:physiopathology* / Q000628:therapy*; D009206:Myocardium; D010101:Oxygen Consumption / Q000502:physiology; D013552:Swine; D014655:Vascular Resistance / Q000502:physiology; D017725:Ventricular Pressure / Q000502:physiology