Abstract 16392: Concomitant Vagal Nerve Stimulation With Total Flow Support of Left Ventricular Assist Device Virtually Nullifies the Infarct Size in Ischemia Reperfusion Model
Background: A significant number of patients with acute myocardial infarction (AMI) end up with heart failure in the long term. This is to say, the latest reperfusion therapy remains unsatisfactory because of the presence of unsalvaged myocardium. Left ventricular assist device (VAD) is known to decrease myocardial oxygen consumption and thereby anti-ischemic. It is also well known that vagal nerve stimulation (VNS) exerts a powerful anti-infarct effect. We investigate how the combination treatment of VNS with VAD reduces the infarct size in ischemia reperfusion (IR) model.
Methods: We created ischemia by occluding major branches of the left anterior descending coronary artery (90min) and reperfused for the following 5 hours. VNS was adjusted to reduce heart rate by 10-20% from the baseline. VAD flow was adjusted either a half of native cardiac output (CO) (H-VAD) or a totally VAD dependent circulation (T-VAD) where VAD prevented LV from ejecting. We allocated 16 anesthetized dogs into 4 groups, Control, VNS, VNS/H-VAD, and VNS/T-VAD. We started either one of the above treatments at the moment we created ischemia and continued to the end of reperfusion. We assessed the infract size (normalized by the risk area) and the serum level of creatine kinase MB (CK-MB).
Results: Mean aortic pressure after the end of IR did not differ among 4 groups (85~107 mmHg). Left atrial pressures were significantly lower in VNS/T-VAD (Control: 13.0±3.1, VNS: 10.6±0.6, VNS/H-VAD: 11.2±3.0, VNS/T-VAD: -1.2±3.1 mmHg, p<0.05). Although VNS and VNS/H-VAD reduced the infarct size (Control: 44.0±4.4, VNS: 24.8±4.8, VNS/H-VAD:13.9±3.9%, p<0.05), VNS/T-VAD virtually nullified the infarct size below the detection thresholds and siginificantly lowered CK-MB (Fig. 1).
Conclusions: The combination treatment of VNS and VAD nearly nullifies the infarct size below the detection threshold in IR model. This treatment would prevent AMI patients from heart failure and improve survival in the long term.
- Ventricular assist devices
- Acute coronary syndromes
- Pressure – volume relation
- Infarct size
- © 2013 by American Heart Association, Inc.