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Louradour J, Ottersberg R, Segiser A, Olejnik A, Martínez-Salazar B, Siegrist M, Egle M, Barbieri M, Nimani S, Alerni N, Döring Y, Odening KE, Longnus S. Simultaneous assessment of mechanical and electrical function in Langendorff-perfused ex-vivo mouse hearts. Front Cardiovasc Med 2023; 10:1293032. [PMID: 38028448 PMCID: PMC10663365 DOI: 10.3389/fcvm.2023.1293032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Accepted: 10/23/2023] [Indexed: 12/01/2023] Open
Abstract
Background The Langendorff-perfused ex-vivo isolated heart model has been extensively used to study cardiac function for many years. However, electrical and mechanical function are often studied separately-despite growing proof of a complex electro-mechanical interaction in cardiac physiology and pathology. Therefore, we developed an isolated mouse heart perfusion system that allows simultaneous recording of electrical and mechanical function. Methods Isolated mouse hearts were mounted on a Langendorff setup and electrical function was assessed via a pseudo-ECG and an octapolar catheter inserted in the right atrium and ventricle. Mechanical function was simultaneously assessed via a balloon inserted into the left ventricle coupled with pressure determination. Hearts were then submitted to an ischemia-reperfusion protocol. Results At baseline, heart rate, PR and QT intervals, intra-atrial and intra-ventricular conduction times, as well as ventricular effective refractory period, could be measured as parameters of cardiac electrical function. Left ventricular developed pressure (DP), left ventricular work (DP-heart rate product) and maximal velocities of contraction and relaxation were used to assess cardiac mechanical function. Cardiac arrhythmias were observed with episodes of bigeminy during which DP was significantly increased compared to that of sinus rhythm episodes. In addition, the extrasystole-triggered contraction was only 50% of that of sinus rhythm, recapitulating the "pulse deficit" phenomenon observed in bigeminy patients. After ischemia, the mechanical function significantly decreased and slowly recovered during reperfusion while most of the electrical parameters remained unchanged. Finally, the same electro-mechanical interaction during episodes of bigeminy at baseline was observed during reperfusion. Conclusion Our modified Langendorff setup allows simultaneous recording of electrical and mechanical function on a beat-to-beat scale and can be used to study electro-mechanical interaction in isolated mouse hearts.
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Affiliation(s)
- Julien Louradour
- Department of Physiology, Translational Cardiology/Electrophysiology, Institute of Physiology, University of Bern, Bern, Switzerland
| | - Rahel Ottersberg
- Department for BioMedical Research, University of Bern, Bern, Switzerland
- Department of Cardiac Surgery, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Adrian Segiser
- Department for BioMedical Research, University of Bern, Bern, Switzerland
- Department of Cardiac Surgery, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Agnieszka Olejnik
- Department for BioMedical Research, University of Bern, Bern, Switzerland
- Division of Clinical Chemistry and Laboratory Hematology, Department of Medical Laboratory Diagnostics, Faculty of Pharmacy, Wroclaw Medical University, Wroclaw, Poland
| | - Berenice Martínez-Salazar
- Department for BioMedical Research, University of Bern, Bern, Switzerland
- Department of Angiology, Swiss Cardiovascular Center, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Mark Siegrist
- Department for BioMedical Research, University of Bern, Bern, Switzerland
- Department of Angiology, Swiss Cardiovascular Center, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Manuel Egle
- Department for BioMedical Research, University of Bern, Bern, Switzerland
- Department of Cardiac Surgery, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Miriam Barbieri
- Department of Physiology, Translational Cardiology/Electrophysiology, Institute of Physiology, University of Bern, Bern, Switzerland
| | - Saranda Nimani
- Department of Physiology, Translational Cardiology/Electrophysiology, Institute of Physiology, University of Bern, Bern, Switzerland
| | - Nicolò Alerni
- Department of Physiology, Translational Cardiology/Electrophysiology, Institute of Physiology, University of Bern, Bern, Switzerland
| | - Yvonne Döring
- Department for BioMedical Research, University of Bern, Bern, Switzerland
- Department of Angiology, Swiss Cardiovascular Center, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- Institute for Cardiovascular Prevention (IPEK), Ludwig-Maximilians-University Munich (LMU), Munich, Germany
- German Center for Cardiovascular Research (DZHK), Partner Site Munich, Heart Alliance Munich, Munich, Germany
| | - Katja E. Odening
- Department of Physiology, Translational Cardiology/Electrophysiology, Institute of Physiology, University of Bern, Bern, Switzerland
- Department of Cardiology, Translational Cardiology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Sarah Longnus
- Department for BioMedical Research, University of Bern, Bern, Switzerland
- Department of Cardiac Surgery, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
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