# Impella preserves haemodynamics with adequate stressed blood volume and normal pulmonary vascular resistance in a goat model of ventricular fibrillation

## TL;DR

The Impella device helps maintain blood flow to vital organs during ventricular fibrillation in goats when blood volume and lung resistance are normal.

## Contribution

This study demonstrates that the Impella device can preserve systemic and cerebral blood flow during ventricular fibrillation in a controlled goat model.

## Key findings

- Impella support increased arterial pressure in a dose-dependent manner during ventricular fibrillation.
- Impella partially maintained pulmonary artery, carotid artery, and coronary flows during ventricular fibrillation.
- The device preserved blood flow with adequate stressed blood volume and normal pulmonary vascular resistance.

## Abstract

Ventricular fibrillation (VF) is a frequent and life-threatening complication of acute myocardial infarction. Although the Impella device provides circulatory support solely to the left ventricle (LV), emerging reports have suggested that it may partially maintain haemodynamics even during VF. This study sought to examine this phenomenon under controlled experimental conditions.

In eight Saanen goats, we recorded right atrial pressure (RAP), left atrial pressure (LAP), arterial pressure (AP), LV pressure, pulmonary artery flow (PAF), carotid artery flow (CAF), and coronary flow (CoF). We inserted an Impella CP and induced VF using direct current. In Protocol 1, we changed the stressed blood volume (SBV) by blood withdrawal/infusion or pulmonary vascular resistance (PVR) by pulmonary microembolisation and measured the haemodynamics during VF with Impella P4 support (n = 1 each). In Protocol 2 (n = 6), we compared the central and peripheral blood flows between the baseline conditions and three Impella support levels (P0, P4, and P8) during VF. In Protocol 2, an increase of Impella support to P4 and P8 during VF significantly increased AP in a support level-dependent manner (P0, P4, and P8: 26.5 ± 2.5, 57.7 ± 8.7 and 72.0 ± 15.3 mmHg, respectively; P < 0.001) while lowering RAP and LAP. Impella partially maintained PAF (0, 1.2 ± 0.6 and 1.6 ± 0.9 L/min; P = 0.011), CAF (0, 177.6 ± 26.3 and 235.5 ± 44.1 mL/min; P < 0.001), and CoF (0, 68.5 ± 32.0 and 57.8 ± 20.6 mL/min; P = 0.002) during VF.

Impella preserved systemic, cerebral, and coronary blood flow with adequate SBV and normal PVR conditions in a goat model of VF.

Graphical Abstract