Thoracotomy and Pericardiotomy for Access to the Heart in Horses: Surgical Procedure and Effects on Anesthetic Variables.
- Journal Article
- Research Support
- Non-U.S. Gov't
Summary
This research presents a surgical procedure giving complete access to a horse’s heart, and evaluates the impact on the horse’s pulmonary gas exchange during surgery. Two groups were studied: one undergoing the surgical procedure and another as a control group.
Research Methodology
In conducting this research, the researchers used two experimental arms:
- The first arm included 11 Standardbred horses that had atrial fibrillation, a heart condition experimentally induced by tachypacing, a method to deliberately induce rapid heart rate. These horses underwent thoracotomy, which is a surgical procedure to open up the chest.
- The second arm consisted of 6 control Standardbred horses, which were anesthetized for unrelated reasons and thus did not undergo the surgical intervention.
Anesthetic Procedure
The horses were anesthetized using zolazepam and tiletamine. Anesthesia was maintained with isoflurane in 100% oxygen. The horses’ breathing was controlled by intermittent positive pressure ventilation, and no positive end-expiratory pressure was performed.
Surgical Procedure
To obtain complete access to the heart, rib resection, which involves the surgical removal of a rib, and pericardiotomy, opening up the pericardium which is the sac-like covering around the heart, were carried out. Arterial blood samples were drawn before, as well as 5 and 30 minutes after puncturing the pleura parietalis, which is the portion of the lining of the thoracic cavity that covers the chest wall. In 10 out of 11 horses, removal of the fifth rib was enough for heart exposure. In one case, it was necessary to remove the sixth rib as well.
Results of the Study
The research found that the duration of the surgical procedure (thoracotomy, pericardiotomy) was less than 45 minutes. During the thoracotomy, the oxygen partial pressure (PaO2) significantly decreased from 291.8 ± 82.8 mmHg to 165.2 ± 73.5 mmHg but it remained within the normal range compared to the anesthetized control horses. The carbon dioxide partial pressure (PaCO2) also stayed within normal limits during the surgery.
Cite This Article
Publication
Researcher Affiliations
- Faculty of Health and Medical Sciences, Department of Veterinary Clinical Sciences, University of Copenhagen, Taastrup, Denmark. Electronic address: dima@sund.ku.dk.
- School of Veterinary Medicine, Department of Clinical Studies-NBC, University of Pennsylvania, Kennett Square, PA.
- Faculty of Health and Medical Sciences, Department of Veterinary Clinical Sciences, University of Copenhagen, Taastrup, Denmark.
- Faculty of Health and Medical Sciences, Department of Veterinary Clinical Sciences, University of Copenhagen, Taastrup, Denmark.
- Faculty of Health and Medical Sciences, Department of Veterinary Clinical Sciences, University of Copenhagen, Taastrup, Denmark.
- Faculty of Health and Medical Sciences, Department of Veterinary Clinical Sciences, University of Copenhagen, Taastrup, Denmark.
MeSH Terms
- Anesthetics
- Animals
- Horses
- Isoflurane
- Pericardiectomy / veterinary
- Thoracotomy / veterinary
- Tiletamine
Citations
This article has been cited 4 times.- Haugaard SL, Schneider MJ, Kjeldsen ST, Sattler SM, Bastrup JA, Saljic A, Birk JB, Hansen C, Synnestvedt JN, van Hunnik A, Sobota V, Carstensen H, Hopster-Iversen C, Schwarzwald CC, Altintaş A, Barrès R, Jepps TA, Larsen S, Kjøbsted R, Wojtaszewski JFP, Barrado Ballestero S, Roostalu U, Herum KM, Jespersen T, Nattel S, Nissen SD, Buhl R. Metformin Protects Against Persistent Atrial Fibrillation in an Equine Model. Circ Arrhythm Electrophysiol 2025 Dec;18(12):e013850.
- Carstensen H, Nissen SD, Saljic A, Hesselkilde EM, van Hunnik A, Hohl M, Sattler SM, Fløgstad C, Hopster-Iversen C, Verheule S, Böhm M, Schotten U, Jespersen T, Buhl R. Long-Term Training Increases Atrial Fibrillation Sustainability in Standardbred Racehorses. J Cardiovasc Transl Res 2023 Oct;16(5):1205-1219.
- Saljic A, Friederike Fenner M, Winters J, Flethøj M, Eggert Eggertsen C, Carstensen H, Dalgas Nissen S, Melis Hesselkilde E, van Hunnik A, Schotten U, Sørensen U, Jespersen T, Verheule S, Buhl R. Increased fibroblast accumulation in the equine heart following persistent atrial fibrillation. Int J Cardiol Heart Vasc 2021 Aug;35:100842.
- Fenner MF, Gatta G, Sattler S, Kuiper M, Hesselkilde EM, Adler DMT, Smerup M, Schotten U, Sørensen U, Diness JG, Jespersen T, Verheule S, Van Hunnik A, Buhl R. Inhibition of Small-Conductance Calcium-Activated Potassium Current (I (K,Ca)) Leads to Differential Atrial Electrophysiological Effects in a Horse Model of Persistent Atrial Fibrillation. Front Physiol 2021;12:614483.