External counterpulsation of a systemic-to-pulmonary artery shunt increases coronary blood flow in neonatal piglets

William M DeCampli; Virgil Secasanu; I Ricardo Argueta-Morales; Kelly Cox; Constantine Ionan; Alain J Kassab

doi:10.1177/2150135114558850

External counterpulsation of a systemic-to-pulmonary artery shunt increases coronary blood flow in neonatal piglets

World J Pediatr Congenit Heart Surg. 2015 Jan;6(1):75-82. doi: 10.1177/2150135114558850.

Authors

William M DeCampli¹, Virgil Secasanu², I Ricardo Argueta-Morales³, Kelly Cox⁴, Constantine Ionan³, Alain J Kassab⁴

Affiliations

¹ The Heart Center at Arnold Palmer Hospital for Children, Orlando, FL, USA College of Medicine at the University of Central Florida, Orlando, FL, USA College of Engineering and Computer Science, University of Central Florida, Mechanical and Aerospace Engineering, Orlando, FL, USA william.decampli@orlandohealth.com.
² College of Medicine at the University of Central Florida, Orlando, FL, USA.
³ The Heart Center at Arnold Palmer Hospital for Children, Orlando, FL, USA.
⁴ College of Engineering and Computer Science, University of Central Florida, Mechanical and Aerospace Engineering, Orlando, FL, USA.

PMID: 25548347
DOI: 10.1177/2150135114558850

Abstract

Background: Systemic-to-pulmonary artery shunt (SPS) palliation reduces coronary blood flow (CBF), which may precipitate myocardial ischemia postoperatively.

Hypothesis: Counterpulsation (CP) of SPS augments CBF.

Methods: Seven neonatal piglets (4.3 ± 0.23 kg) underwent sternotomy and ductus ligation. With a 5-mm polytetrafluoroethylene graft, SPS was created from innominate to pulmonary artery. A rigid shell holding a 9.5-mm diameter balloon was placed around the graft for CP. Using electrocardiographic signal, CP was initiated to trigger balloon inflation/deflation during the diastolic/systolic intervals, respectively. Instantaneous proximal and distal pulmonary artery and mid-anterior descending coronary artery flow rates were measured using transit time flow probes. Blood pressure and flow rates were recorded during three states: shunt closed, shunt open, and shunt open with CP.

Statistical comparison: Friedman's test and repeated measures analysis of variance.

Results: Diastolic pressure decreased significantly with the shunt open (39 ± 8.4 to 28 ± 4.5 mm Hg, P = .05), then increased with CP (33 ± 2.3 mm Hg, P = .03). Median ratio of pulmonary to systemic flow (Qp/Qs) was 1.19, 1.9, and 1.53 with shunt closed, open, and open with CP, respectively. With CP, both diastolic coronary flow per minute (P = .018) and average diastolic flow rate per diastolic interval (P = .03) increased as well as total coronary flow per minute (P = .066; 19.6% ± 11.7%, 25.2% ± 17.0%, and 15.4% ± 13.9% change from shunt open, respectively). The percentage increase in average diastolic flow rate per diastolic interval correlated strongly with Qp/Qs (R (2) = .838).

Conclusions: In this model of SPS, CP increased diastolic blood pressure and CBF while maintaining significant augmentation of pulmonary blood flow (Qp/Qs). Shunt CP may aid in early postoperative management of palliative congenital heart disease.

Keywords: animal model; circulatory hemodynamics; congenital heart disease; device; innominate-to-pulmonary artery shunt.

Publication types

Evaluation Study
Research Support, Non-U.S. Gov't

MeSH terms

Animals
Blood Pressure
Coronary Circulation / physiology*
Coronary Vessels / surgery*
Counterpulsation*
Heart Defects, Congenital / surgery
Myocardial Ischemia / etiology
Myocardial Ischemia / prevention & control*
Postoperative Complications / prevention & control*
Pulmonary Artery / physiology
Pulmonary Artery / surgery*
Pulmonary Circulation
Swine
Vascular Grafting / methods*