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Renal denervation suppresses atrial fibrillation in a model of renal impairment.

Liang Z, Shi XM, Liu LF, Chen XP, Shan ZL, Lin K, Li J, Chen FK, Li YG, Guo HY, Wang YT - PLoS ONE (2015)

Bottom Line: The main objective of the study was to explore the effects of RDN on AF occurrence and its possible mechanisms in beagles with RI.Cardiac electrophysiological parameters, blood pressure, left ventricular end-diastolic pressure, and AF inducibility were investigated.Heart rate, P wave duration and BP were increased by RI, which were prevented or attenuated by RDN.

View Article: PubMed Central - PubMed

Affiliation: Department of Cardiology, Chinese PLA General Hospital, Beijing, China.

ABSTRACT

Background: A close association exists between renal impairment (RI) and atrial fibrillation (AF) occurrence. Increased activity of the sympathetic nervous system (SNS) may contribute to the development of AF associated with RI. Renal denervation (RDN) decreases central sympathetic activity.

Objective: The main objective of the study was to explore the effects of RDN on AF occurrence and its possible mechanisms in beagles with RI.

Methods: Unilateral RI was induced in beagles by embolization of small branches of the renal artery in the right kidney using gelatin sponge granules in Model (n = 6) and RDN group (n = 6). The Sham group (n = 6) underwent the same procedure, except for embolization. Then animals in RDN group underwent radiofrequency ablation of the renal sympathetic nerve. Cardiac electrophysiological parameters, blood pressure, left ventricular end-diastolic pressure, and AF inducibility were investigated. The activity of the SNS, renin-angiotensin-aldosterone system (RAAS), inflammation and atrial interstitial fibrosis were measured.

Results: Embolization of small branches of the renal artery in the right kidney led to ischemic RI. Heart rate, P wave duration and BP were increased by RI, which were prevented or attenuated by RDN. Atrial effective refractory period was shortened and AF inducibility was increased by RI, which were prevented by RDN. Antegrade Wenckebach point was shortened, atrial and ventricular rates during AF were increased by RI, which were attenuated or prevented by RDN. Levels of norepinephrine, renin and aldosterone in plasma, norepinephrine, angiotensin II, aldosterone, interleukin-6 and high sensitivity C-reactive protein in atrial tissue were elevated, and atrial interstitial fibrosis was enhanced by RI, which were attenuated by RDN.

Conclusions: RDN significantly reduced AF inducibility, prevented the atrial electrophysiological changes in a model of RI by combined reduction of sympathetic drive and RAAS activity, and inhibition of inflammation activity and fibrotic pathway in atrial tissue.

No MeSH data available.


Related in: MedlinePlus

Fluoroscopic images of the right renal artery.Images of the right renal artery angiography before transcatheter embolization (A) and after transcatheter embolization (B) in RDN group. Images of ablation catheter which was placed in the right renal artery after renal impairment for ablation (C). Images of the right renal artery angiography after 2 weeks of ablation (D).
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pone.0124123.g001: Fluoroscopic images of the right renal artery.Images of the right renal artery angiography before transcatheter embolization (A) and after transcatheter embolization (B) in RDN group. Images of ablation catheter which was placed in the right renal artery after renal impairment for ablation (C). Images of the right renal artery angiography after 2 weeks of ablation (D).

Mentions: Right renal artery angiography was performed before (Fig 1A) and after (Fig 1B) transcatheter embolization in the RDN group. Small renal artery branches were occluded after transcatheter embolization, whereas the main renal artery or sub-segment renal artery remained fluent. Fig 1C shows representative images of ablation using 6F ablation catheter in the right renal artery after RI. The right renal artery had no obvious stenosis after 2 weeks of ablation (Fig 1D). The CCr in the Model and RDN groups were slightly decreased by 22.2% and 26.4% separately compared with the Sham group after 2 weeks of RI (P < 0.05 for each). There was no difference of CCr between the Model and RDN groups. Fig 2 shows representative images of HE staining of the right renal artery and renal sympathetic nerves (arrow indicated) with different magnification in the RDN (B, D) and Model (A, C) groups respectively. Renal sympathetic nerves were intact and surrounded by outer membrane in the Model group. On the contrary, renal sympathetic nerves were damaged in the RDN group, which had contracted morphology and lost surrounding outer membrane. Approximately 49% of renal nerves observed exhibited injury due to the RDN procedure (n = 96 of 196). More than 90% of renal nerves were found between 1.0–3.0mm from the renal artery lumen-intima interface and about 90% of the injured nerves were found in this range. The impedance decreased from 252.5±32.5Ω to 233.8±30.6Ω (P < 0.05, n = 24) after ablation in the RDN group.


Renal denervation suppresses atrial fibrillation in a model of renal impairment.

Liang Z, Shi XM, Liu LF, Chen XP, Shan ZL, Lin K, Li J, Chen FK, Li YG, Guo HY, Wang YT - PLoS ONE (2015)

Fluoroscopic images of the right renal artery.Images of the right renal artery angiography before transcatheter embolization (A) and after transcatheter embolization (B) in RDN group. Images of ablation catheter which was placed in the right renal artery after renal impairment for ablation (C). Images of the right renal artery angiography after 2 weeks of ablation (D).
© Copyright Policy
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4401704&req=5

pone.0124123.g001: Fluoroscopic images of the right renal artery.Images of the right renal artery angiography before transcatheter embolization (A) and after transcatheter embolization (B) in RDN group. Images of ablation catheter which was placed in the right renal artery after renal impairment for ablation (C). Images of the right renal artery angiography after 2 weeks of ablation (D).
Mentions: Right renal artery angiography was performed before (Fig 1A) and after (Fig 1B) transcatheter embolization in the RDN group. Small renal artery branches were occluded after transcatheter embolization, whereas the main renal artery or sub-segment renal artery remained fluent. Fig 1C shows representative images of ablation using 6F ablation catheter in the right renal artery after RI. The right renal artery had no obvious stenosis after 2 weeks of ablation (Fig 1D). The CCr in the Model and RDN groups were slightly decreased by 22.2% and 26.4% separately compared with the Sham group after 2 weeks of RI (P < 0.05 for each). There was no difference of CCr between the Model and RDN groups. Fig 2 shows representative images of HE staining of the right renal artery and renal sympathetic nerves (arrow indicated) with different magnification in the RDN (B, D) and Model (A, C) groups respectively. Renal sympathetic nerves were intact and surrounded by outer membrane in the Model group. On the contrary, renal sympathetic nerves were damaged in the RDN group, which had contracted morphology and lost surrounding outer membrane. Approximately 49% of renal nerves observed exhibited injury due to the RDN procedure (n = 96 of 196). More than 90% of renal nerves were found between 1.0–3.0mm from the renal artery lumen-intima interface and about 90% of the injured nerves were found in this range. The impedance decreased from 252.5±32.5Ω to 233.8±30.6Ω (P < 0.05, n = 24) after ablation in the RDN group.

Bottom Line: The main objective of the study was to explore the effects of RDN on AF occurrence and its possible mechanisms in beagles with RI.Cardiac electrophysiological parameters, blood pressure, left ventricular end-diastolic pressure, and AF inducibility were investigated.Heart rate, P wave duration and BP were increased by RI, which were prevented or attenuated by RDN.

View Article: PubMed Central - PubMed

Affiliation: Department of Cardiology, Chinese PLA General Hospital, Beijing, China.

ABSTRACT

Background: A close association exists between renal impairment (RI) and atrial fibrillation (AF) occurrence. Increased activity of the sympathetic nervous system (SNS) may contribute to the development of AF associated with RI. Renal denervation (RDN) decreases central sympathetic activity.

Objective: The main objective of the study was to explore the effects of RDN on AF occurrence and its possible mechanisms in beagles with RI.

Methods: Unilateral RI was induced in beagles by embolization of small branches of the renal artery in the right kidney using gelatin sponge granules in Model (n = 6) and RDN group (n = 6). The Sham group (n = 6) underwent the same procedure, except for embolization. Then animals in RDN group underwent radiofrequency ablation of the renal sympathetic nerve. Cardiac electrophysiological parameters, blood pressure, left ventricular end-diastolic pressure, and AF inducibility were investigated. The activity of the SNS, renin-angiotensin-aldosterone system (RAAS), inflammation and atrial interstitial fibrosis were measured.

Results: Embolization of small branches of the renal artery in the right kidney led to ischemic RI. Heart rate, P wave duration and BP were increased by RI, which were prevented or attenuated by RDN. Atrial effective refractory period was shortened and AF inducibility was increased by RI, which were prevented by RDN. Antegrade Wenckebach point was shortened, atrial and ventricular rates during AF were increased by RI, which were attenuated or prevented by RDN. Levels of norepinephrine, renin and aldosterone in plasma, norepinephrine, angiotensin II, aldosterone, interleukin-6 and high sensitivity C-reactive protein in atrial tissue were elevated, and atrial interstitial fibrosis was enhanced by RI, which were attenuated by RDN.

Conclusions: RDN significantly reduced AF inducibility, prevented the atrial electrophysiological changes in a model of RI by combined reduction of sympathetic drive and RAAS activity, and inhibition of inflammation activity and fibrotic pathway in atrial tissue.

No MeSH data available.


Related in: MedlinePlus