Francesco Paolo Lo Muzio1, Giacomo Rozzi1, Stefano Rossi2, Amparo Guerrero Gerbolés2, Lorenzo Fassina3, Giovanna Pelà2, Giovanni Battista Luciani4, Michele Miragoli5. 1. Department of Surgery, Dentistry, Paediatrics and Gynaecology, University of Verona Via S. Francesco 22, 37129, Verona, Italy; Department of Medicine and Surgery, University di Parma, via Gramsci 14, 43126, Parma, Italy. 2. Department of Medicine and Surgery, University di Parma, via Gramsci 14, 43126, Parma, Italy. 3. Department of Industrial Engineering and Informatics, University of Pavia, Via Ferrata 1, 27100, Pavia, Italy. 4. Department of Surgery, Dentistry, Paediatrics and Gynaecology, University of Verona Via S. Francesco 22, 37129, Verona, Italy. 5. Department of Medicine and Surgery, University di Parma, via Gramsci 14, 43126, Parma, Italy; Humanitas Clinical and Research Center, Via Manzoni 56, 20089, Rozzano, Italy. Electronic address: michele.miragoli@unipr.it.
Abstract
BACKGROUND: Gender-related cardiac mechanics following the electrical activity has been investigated from basic to clinical research, but results are still controversial. The aim of this work is to study the gender related cardiac mechanics and to focus on its heart rate dependency. METHODS: We employed 12 Sprague Dawley rats (5 males and 7 females) of the same age and, through a novel high resolution artificial vision contactless approach, we evaluated in-situ cardiac kinematic. The hearts were paced on the right atria appendage via cathodal stimuli at rising frequency. RESULTS: Kinematic data obtained at rising pacing rates are different between male and female rat hearts: male tended to maintain the same level of cardiac force, energy and contractility, while female responded with an increment of such parameters at increasing heart rate. Female hearts preserved their pattern of contraction and epicardial torsion (vorticity) at rising pacing rates compared to male. Furthermore, we observed a difference in the mechanical restitution: systolic time vs. diastolic time, as an index of cardiac performance, reached higher value in male compared to female hearts. CONCLUSION: Our innovative technology was capable to evaluate in-situ rat epicardial kinematic at high stimulation frequency, revealing that male preserved kinematic parameters but varying the pattern of contraction/relaxation. On the contrary, female preserved the pattern of contraction/relaxation increasing kinematic parameters.
BACKGROUND: Gender-related cardiac mechanics following the electrical activity has been investigated from basic to clinical research, but results are still controversial. The aim of this work is to study the gender related cardiac mechanics and to focus on its heart rate dependency. METHODS: We employed 12 Sprague Dawley rats (5 males and 7 females) of the same age and, through a novel high resolution artificial vision contactless approach, we evaluated in-situ cardiac kinematic. The hearts were paced on the right atria appendage via cathodal stimuli at rising frequency. RESULTS: Kinematic data obtained at rising pacing rates are different between male and female rat hearts: male tended to maintain the same level of cardiac force, energy and contractility, while female responded with an increment of such parameters at increasing heart rate. Female hearts preserved their pattern of contraction and epicardial torsion (vorticity) at rising pacing rates compared to male. Furthermore, we observed a difference in the mechanical restitution: systolic time vs. diastolic time, as an index of cardiac performance, reached higher value in male compared to female hearts. CONCLUSION: Our innovative technology was capable to evaluate in-situ rat epicardial kinematic at high stimulation frequency, revealing that male preserved kinematic parameters but varying the pattern of contraction/relaxation. On the contrary, female preserved the pattern of contraction/relaxation increasing kinematic parameters.
Authors: Lorenzo Fassina; Maria Rita Assenza; Michele Miragoli; Andrea M Isidori; Fabio Naro; Federica Barbagallo Journal: Biomedicines Date: 2022-03-10