Control of ventricular unloading using an electrocardiogram-synchronized Thoratec paracorporeal ventricular assist device

Amacher, Raffael; Weber, Alberto; Brinks, Henriette; Axiak, Shannon; Ferreira, Antonio; Guzzella, Lino; Carrel, Thierry; Antaki, James; Vandenberghe, Stijn (2013). Control of ventricular unloading using an electrocardiogram-synchronized Thoratec paracorporeal ventricular assist device. Journal of thoracic and cardiovascular surgery, 146(3), pp. 710-717. St. Louis, Mo.: Mosby 10.1016/j.jtcvs.2012.12.048

Full text not available from this repository. (Request a copy)

OBJECTIVE: Current pulsatile ventricular assist devices operate asynchronous with the left ventricle in fixed-rate or fill-to-empty modes because electrocardiogram-triggered modes have been abandoned. We hypothesize that varying the ejection delay in the synchronized mode yields more precise control of hemodynamics and left ventricular loading. This allows for a refined management that may be clinically beneficial. METHODS: Eight sheep received a Thoratec paracorporeal ventricular assist device (Thoratec Corp, Pleasanton, Calif) via ventriculo-aortic cannulation. Left ventricular pressure and volume, aortic pressure, pulmonary flow, pump chamber pressure, and pump inflow and outflow were recorded. The pump was driven by a clinical pneumatic drive unit (Medos Medizintechnik AG, Stolberg, Germany) synchronously with the native R-wave. The start of pump ejection was delayed between 0% and 100% of the cardiac period in 10% increments. For each of these delays, hemodynamic variables were compared with baseline data using paired t tests. RESULTS: The location of the minimum of stroke work was observed at a delay of 10% (soon after aortic valve opening), resulting in a median of 43% reduction in stroke work compared with baseline. Maximum stroke work occurred at a median delay of 70% with a median stroke work increase of 11% above baseline. Left ventricular volume unloading expressed by end-diastolic volume was most pronounced for copulsation (delay 0%). CONCLUSIONS: The timing of pump ejection in synchronized mode yields control over left ventricular energetics and can be a method to achieve gradual reloading of a recoverable left ventricle. The traditionally suggested counterpulsation is not optimal in ventriculo-aortic cannulation when maximum unloading is desired.

Item Type:

Journal Article (Original Article)

Division/Institute:

04 Faculty of Medicine > Department of Cardiovascular Disorders (DHGE) > Clinic of Cardiovascular Surgery
05 Veterinary Medicine > Department of Clinical Veterinary Medicine (DKV) > DKV - Anaesthesiology
10 Strategic Research Centers > ARTORG Center for Biomedical Engineering Research > ARTORG Center - Cardiovascular Engineering (CVE)

UniBE Contributor:

Weber, Alberto; Most, Henriette; Axiak, Shannon; Carrel, Thierry and Vandenberghe, Stijn

Subjects:

600 Technology > 610 Medicine & health

ISSN:

0022-5223

Publisher:

Mosby

Language:

English

Submitter:

Factscience Import

Date Deposited:

04 Oct 2013 14:39

Last Modified:

21 Oct 2019 11:22

Publisher DOI:

10.1016/j.jtcvs.2012.12.048

PubMed ID:

23317942

Web of Science ID:

000323605800039

Uncontrolled Keywords:

Animals, Aorta, Arterial Pressure, Disease Models, Animal, Electrocardiography, Heart Rate, Heart-Assist Devices, Prosthesis Design, Pulmonary Circulation, Pulsatile Flow, Regional Blood Flow, Sheep, Stroke Volume, Time Factors, Ventricular Dysfunction, Left, Ventricular Function, Left, Ventricular Pressure

URI:

https://boris.unibe.ch/id/eprint/15717 (FactScience: 223146)

Actions (login required)

Edit item Edit item
Provide Feedback