Arrhythmogenic Interaction Between Sympathetic Tone and Mechanical Stretch in Rat Pulmonary Vein Myocardium
Rapid firing from pulmonary veins (PVs) frequently initiates atrial fibrillation, which is a common comorbidity associated with hypertension, heart failure, and valvular disease, i.e., conditions that pathologically increase cardiomyocyte stretch. Autonomic tone plays a crucial role in PV arrhythmog...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2020-03-01
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| Series: | Frontiers in Physiology |
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| Online Access: | https://www.frontiersin.org/article/10.3389/fphys.2020.00237/full |
| _version_ | 1819231759013773312 |
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| author | Yuriy V. Egorov Leonid V. Rosenshtraukh Alexey V. Glukhov |
| author_facet | Yuriy V. Egorov Leonid V. Rosenshtraukh Alexey V. Glukhov |
| author_sort | Yuriy V. Egorov |
| collection | DOAJ |
| description | Rapid firing from pulmonary veins (PVs) frequently initiates atrial fibrillation, which is a common comorbidity associated with hypertension, heart failure, and valvular disease, i.e., conditions that pathologically increase cardiomyocyte stretch. Autonomic tone plays a crucial role in PV arrhythmogenesis, while its interplay with myocardium stretch remains uncertain. Two-microelectrode technique was used to characterize electrophysiological response of Wistar rat PV to adrenaline at baseline and under mild (150 mg of applied weight that corresponds to a pulmonary venous pressure of 1 mmHg) and moderate (10 g, ∼26 mmHg) stretch. Low concentrations of adrenaline (25–100 nmol/L) depolarized the resting membrane potential selectively within distal PV (by 26 ± 2 mV at baseline, by 18 ± 1 mV at 150 mg, P < 0.001, and by 5.9 ± 1.1 mV at 10 g, P < 0.01) suppressing action potential amplitude and resulting in intra-PV conduction dissociation and rare episodes of spontaneous activity (arrhythmia index of 0.4 ± 0.2, NS vs. no activity at baseline). In contrast, 1–10 μmol/L of adrenaline recovered intra-PV propagation. While mild stretch did not affect PV electrophysiology at baseline, moderate stretch depolarized the resting potential within distal PV (-56 ± 2 mV vs. -82 ± 1 mV at baseline, P < 0.01), facilitated the triggering of rapid PV firing by adrenaline (arrhythmia index: 4.4 ± 0.2 vs. 1.3 ± 0.4 in unstretched, P < 0.001, and 1.7 ± 0.8 in mildly stretched preparations, P < 0.005, at 10 μmol/L adrenaline) and induced frequent episodes of potentially arrhythmogenic atrial “echo” extra beats. Our findings demonstrate complex interactions between the sympathetic tone and mechanical stretch in the development of arrhythmogenic activity within PVs that may impact an increased atrial fibrillation vulnerability in patients with elevated blood pressure. |
| first_indexed | 2024-12-23T11:50:04Z |
| format | Article |
| id | doaj.art-15e19df565a947ffbb54b64896f3a7a4 |
| institution | Directory Open Access Journal |
| issn | 1664-042X |
| language | English |
| last_indexed | 2024-12-23T11:50:04Z |
| publishDate | 2020-03-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Physiology |
| spelling | doaj.art-15e19df565a947ffbb54b64896f3a7a42022-12-21T17:48:13ZengFrontiers Media S.A.Frontiers in Physiology1664-042X2020-03-011110.3389/fphys.2020.00237516178Arrhythmogenic Interaction Between Sympathetic Tone and Mechanical Stretch in Rat Pulmonary Vein MyocardiumYuriy V. Egorov0Leonid V. Rosenshtraukh1Alexey V. Glukhov2Laboratory of Heart Electrophysiology, Russian Cardiology Research Centre, Institute of Experimental Cardiology, Moscow, RussiaLaboratory of Heart Electrophysiology, Russian Cardiology Research Centre, Institute of Experimental Cardiology, Moscow, RussiaDepartment of Medicine, School of Medicine and Public Health, University of Wisconsin–Madison, Madison, WI, United StatesRapid firing from pulmonary veins (PVs) frequently initiates atrial fibrillation, which is a common comorbidity associated with hypertension, heart failure, and valvular disease, i.e., conditions that pathologically increase cardiomyocyte stretch. Autonomic tone plays a crucial role in PV arrhythmogenesis, while its interplay with myocardium stretch remains uncertain. Two-microelectrode technique was used to characterize electrophysiological response of Wistar rat PV to adrenaline at baseline and under mild (150 mg of applied weight that corresponds to a pulmonary venous pressure of 1 mmHg) and moderate (10 g, ∼26 mmHg) stretch. Low concentrations of adrenaline (25–100 nmol/L) depolarized the resting membrane potential selectively within distal PV (by 26 ± 2 mV at baseline, by 18 ± 1 mV at 150 mg, P < 0.001, and by 5.9 ± 1.1 mV at 10 g, P < 0.01) suppressing action potential amplitude and resulting in intra-PV conduction dissociation and rare episodes of spontaneous activity (arrhythmia index of 0.4 ± 0.2, NS vs. no activity at baseline). In contrast, 1–10 μmol/L of adrenaline recovered intra-PV propagation. While mild stretch did not affect PV electrophysiology at baseline, moderate stretch depolarized the resting potential within distal PV (-56 ± 2 mV vs. -82 ± 1 mV at baseline, P < 0.01), facilitated the triggering of rapid PV firing by adrenaline (arrhythmia index: 4.4 ± 0.2 vs. 1.3 ± 0.4 in unstretched, P < 0.001, and 1.7 ± 0.8 in mildly stretched preparations, P < 0.005, at 10 μmol/L adrenaline) and induced frequent episodes of potentially arrhythmogenic atrial “echo” extra beats. Our findings demonstrate complex interactions between the sympathetic tone and mechanical stretch in the development of arrhythmogenic activity within PVs that may impact an increased atrial fibrillation vulnerability in patients with elevated blood pressure.https://www.frontiersin.org/article/10.3389/fphys.2020.00237/fullpulmonary veinsstretcharrhythmiamechano-electrical responseadrenalin |
| spellingShingle | Yuriy V. Egorov Leonid V. Rosenshtraukh Alexey V. Glukhov Arrhythmogenic Interaction Between Sympathetic Tone and Mechanical Stretch in Rat Pulmonary Vein Myocardium Frontiers in Physiology pulmonary veins stretch arrhythmia mechano-electrical response adrenalin |
| title | Arrhythmogenic Interaction Between Sympathetic Tone and Mechanical Stretch in Rat Pulmonary Vein Myocardium |
| title_full | Arrhythmogenic Interaction Between Sympathetic Tone and Mechanical Stretch in Rat Pulmonary Vein Myocardium |
| title_fullStr | Arrhythmogenic Interaction Between Sympathetic Tone and Mechanical Stretch in Rat Pulmonary Vein Myocardium |
| title_full_unstemmed | Arrhythmogenic Interaction Between Sympathetic Tone and Mechanical Stretch in Rat Pulmonary Vein Myocardium |
| title_short | Arrhythmogenic Interaction Between Sympathetic Tone and Mechanical Stretch in Rat Pulmonary Vein Myocardium |
| title_sort | arrhythmogenic interaction between sympathetic tone and mechanical stretch in rat pulmonary vein myocardium |
| topic | pulmonary veins stretch arrhythmia mechano-electrical response adrenalin |
| url | https://www.frontiersin.org/article/10.3389/fphys.2020.00237/full |
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