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Selective inhibition of electrical conduction within the pulmonary veins by ?1-adrenergic receptors activation in the Rat.

ABSTRACT: Pulmonary veins (PV) are involved in the pathophysiology of paroxysmal atrial fibrillation. In the rat, left atrium (LA) and PV cardiomyocytes have different reactions to ?1-adrenergic receptor activation. In freely beating atria-PV preparations, we found that electrical field potential (EFP) originated from the sino-atrial node propagated through the LA and the PV. The ?1-adrenergic receptor agonist cirazoline induced a progressive loss of EFP conduction in the PV whereas it was maintained in the LA. This could be reproduced in preparations electrically paced at 5?Hz in LA. During pacing at 10?Hz in the PV where high firing rate ectopic foci can occur, cirazoline stopped EFP conduction from the PV to the LA, which allowed the sino-atrial node to resume its pace-making function. Loss of conduction in the PV was associated with depolarization of the diastolic membrane potential of PV cardiomyocytes. Adenosine, which reversed the cirazoline-induced depolarization of the diastolic membrane potential of PV cardiomyocytes, restored full over-shooting action potentials and EFP conduction in the PV. In conclusion, selective activation of ?1-adrenergic receptors results in the abolition of electrical conduction within the PV. These results highlight a potentially novel pharmacological approach to treat paroxysmal atrial fibrillation by targeting directly the PV myocardium.

SUBMITTER: Bredeloux P

PROVIDER: S-EPMC7096464 | biostudies-literature | 2020 Mar

REPOSITORIES: biostudies-literature

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Selective inhibition of electrical conduction within the pulmonary veins by α1-adrenergic receptors activation in the Rat.

Bredeloux Pierre P Findlay Ian I Pasqualin Côme C Hocini Mélèze M Bernus Olivier O Maupoil Véronique V

Scientific reports 20200325 1

Pulmonary veins (PV) are involved in the pathophysiology of paroxysmal atrial fibrillation. In the rat, left atrium (LA) and PV cardiomyocytes have different reactions to α1-adrenergic receptor activation. In freely beating atria-PV preparations, we found that electrical field potential (EFP) originated from the sino-atrial node propagated through the LA and the PV. The α1-adrenergic receptor agonist cirazoline induced a progressive loss of EFP conduction in the PV whereas it was maintained in t ...[more]

PMID: 32214185

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Dataset Information

Selective inhibition of electrical conduction within the pulmonary veins by ?1-adrenergic receptors activation in the Rat.

Publications

Selective inhibition of electrical conduction within the pulmonary veins by α1-adrenergic receptors activation in the Rat.

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