PEA I and PEA II based implantable haemodynamic monitor: pre clinical studies in sheep.

Aims: The aims of this study were first, to demonstrate that Peak Endocardial Acceleration during isovolumic systole (PEA I) is related to positive peak LVdP/dt, while Peak Endocardial Acceleration during isovolumic relaxation time (PEA II) is related to aortic diastolic pressure (ADP) and to negative peak LVdP/dt; and second, to test if the simultaneous recording of PEA I and PEA II offers a new chance to monitor indexes of LV systolic and diastolic function.
Methods: An implantable haemodynamic monitor, based on PEA I and PEA II measurements via a microaccelerometer sensor located in the tip of a pacing lead, screwed into the right ventricle, was tested in nine sheep at baseline and during acute haemodynamic interventions: nitrate (0.1 mg/ kg), metaraminol (0.15 mg/kg), dobutamine (5 microg/kg) infusion. ADP, positive and negative peak LVdP/dt were simultaneously recorded by an aortic and left ventricular Millar catheter.
Results: PEA I changes were significantly related to positive peak LVdP/dt changes during dobutamine induced inotropic changes (r = 0.83, P < 0.001). PEA II changes were significantly related to both ADP (r = 0.91, P < 0.001) and negative peak LVdP/dt changes (r = 0.92, P < 0.001) during nitrate induced hypotension and metaraminol induced hypertension.
Conclusion: The simultaneous recording of PEA I and PEA II with an implantable system offers a new chance to monitor indexes of LV systolic and diastolic function.