Randomised comparison of percutaneous left ventricular assist device with open-chest cardiac massage and with surgical assist device during ischaemic cardiac arrest.

AIMS: A percutaneous left ventricular assist device can maintain blood flow to vital organs during ventricular fibrillation and may improve outcomes in ischaemic cardiac arrest. We compared haemodynamic and clinical effects of a percutaneous left ventricular assist device with a larger device deployed via endovascular prosthesis and with open-chest cardiac massage during ischaemic cardiac arrest. METHODS: Eighteen swine were randomised into three groups. After thoracotomy, coronary ischaemia and ventricular fibrillation was induced. Cardiac output was measured with transit-time flowmetry. Tissue perfusion was measured with microspheres. Defibrillation was performed after 20 min. RESULTS: Cardiac output with cardiac massage was 1129 mL min⁻¹ vs. 1169 mL min⁻¹ with the percutaneous- and 570 mL min⁻¹ with the surgical device (P < 0.05 surgical vs. others). End-tidal CO2 was 3.3 kPa with cardiac massage vs. 3.2 kPa with the percutaneous- and 2.3 kPa with the surgical device (P < 0.05 surgical vs. others). Subepicardial perfusion was 0.33 mL min⁻¹ g⁻¹ with cardiac massage vs. 0.62 mL min⁻¹ g⁻¹ with both devices (P < 0.05 devices vs. massage), cerebral perfusion was comparable between groups (all reported values after 3 min cardiac arrest, all P<0.05 vs. baseline, all P = NS for 3 min vs. 15 min). Return of spontaneous circulation was achieved in 5/6 subjects with cardiac massage vs. 6/6 with the percutaneous- and 4/6 with the surgical device (P = NS). CONCLUSION: The percutaneous device improved myocardial perfusion, maintained cerebral perfusion and systemic circulation with similar rates of successful defibrillation vs. cardiac massage. Increased delivery was not obtained with the surgical device during cardiac arrest.

Percutaneous left ventricular assist device can prevent acute cerebral ischaemia during ventricular fibrillation.

AIMS: A percutaneous left ventricular assist device has been shown to be able to perfuse cardiac and cerebral tissues during cardiac arrest and may be a useful supplement to current methods in resuscitation. We wished to assess device-assisted circulation during cardiac arrest with microspheres injections and continuous end-tidal CO(2) monitoring, and used cerebral microdialysis to detect ischaemia in the brain. METHODS: 12 anaesthetised pigs had microdialysis and pressure catheters implanted via craniotomy. The percutaneous assist device was deployed transfemorally. Ventricular fibrillation was induced by angioplasty-balloon occlusion of the left coronary artery. Cerebral microdialysis samples representing 0-20 and 20-40 min of cardiac arrest with assisted circulation were analysed for markers of cerebral injury (glucose, pyruvate, lactate, and glycerol). RESULTS: Microdialysis showed no ischaemic changes after 20 min of cardiac arrest (P=NS to Baseline for glucose, glycerol, lactate, pyruvate and lactate/pyruvate ratio) in subjects with maintained end-tidal CO(2) values above 1.3 kPa (10 mmHg). After 40 min only lactate showed a significant change compared to Baseline (P<0.05). Microspheres flow to the brain was 57% and myocardial flow was 72% compared to Baseline after 15 min (P<0.05). After 45 min flow declined to 22% and 40% of Baseline, respectively (P=NS vs. 15 min). CONCLUSIONS: A percutaneous left ventricular assist device may prevent ischaemic cerebral injury during cardiac arrest for a limited time. Cerebral injury and tissue perfusion were indicated by end-tidal CO(2).