External Counterpulsation Of A Systemic-To-Pulmonary Artery Shunt Increases Coronary Blood Flow In Neonatal Piglets

Keywords

Animal model; Circulatory hemodynamics; Congenital heart disease; Device; Innominate-to-pulmonary artery shunt

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 (R2 =.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.

Publication Date

1-1-2015

Publication Title

World Journal for Pediatric and Congenital Hearth Surgery

Volume

6

Issue

1

Number of Pages

75-82

Document Type

Article

Personal Identifier

scopus

DOI Link

https://doi.org/10.1177/2150135114558850

Socpus ID

84938504546 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/84938504546

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