Limits...
Renal denervation decreases effective refractory period but not inducibility of ventricular fibrillation in a healthy porcine biomodel: a case control study.

Lubanda JC, Kudlicka J, Mlcek M, Chochola M, Neuzil P, Linhart A, Kittnar O - J Transl Med (2015)

Bottom Line: According to histological findings, RDN procedure was successfully performed in all biomodels.RDN decreased the influence of sympathetic nerve system on the heart conduction system in healthy porcine biomodel.However, the electrophysiological study was not associated with a decrease of VF inducibility after RDN.

View Article: PubMed Central - PubMed

Affiliation: 2nd Department of Medicine - Department of Cardiovascular Medicine, First Faculty of Medicine, Charles University in Prague and General University Hospital in Prague, U Nemocnice 2, Prague 2, 128 00, Czech Republic. jean-claude.lubanda@vfn.cz.

ABSTRACT

Background: Ventricular arrhythmias play an important role in cardiovascular mortality especially in patients with impaired cardiac and autonomic function. The aim of this experimental study was to determine, if renal denervation (RDN) could decrease the inducibility of ventricular fibrillation (VF) in a healthy porcine biomodel.

Methods: Controlled electrophysiological study was performed in 6 biomodels 40 days after RDN (RDN group) and in 6 healthy animals (control group). The inducibility of VF was tested by programmed ventricular stimulation from the apex of right ventricle (8 basal stimuli coupled with up to 4 extrastimuli) always three times in each biomodel using peripheral extracorporeal oxygenation for hemodynamic support. Further, basal heart rate (HR), PQ and QT intervals and effective refractory period of ventricles (ERP) were measured. Technical success of RDN was evaluated by histological examination.

Results: According to histological findings, RDN procedure was successfully performed in all biomodels. Comparing the groups, basal HR was lower in RDN group: 79 (IQR 58; 88) vs. 93 (72; 95) beats per minute (p = 0.003); PQ interval was longer in RDN group: 145 (133; 153) vs. 115 (113; 120) ms (p < 0.0001) and QTc intervals were comparable: 402 (382; 422) ms in RDN vs. 386 (356; 437) ms in control group (p = 0.1). ERP was prolonged significantly in RDN group: 159 (150; 169) vs. 140 (133; 150) ms (p = 0.001), but VF inducibility was the same (18/18 vs. 18/18 attempts).

Conclusions: RDN decreased the influence of sympathetic nerve system on the heart conduction system in healthy porcine biomodel. However, the electrophysiological study was not associated with a decrease of VF inducibility after RDN.

No MeSH data available.


Related in: MedlinePlus

Scheme of electrophysiological study. 8xS1 indicates the train of eight basic stimuli; S2-5, up to five extrastimuli; ERP, effective refractory period; VF, ventricular fibrillation; defib, defibrillation; ECMO high, increasing of the ECMO flow to 80-100 mL/kg/min after onset of VF until the sinus rhythm was restored.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC4300561&req=5

Fig2: Scheme of electrophysiological study. 8xS1 indicates the train of eight basic stimuli; S2-5, up to five extrastimuli; ERP, effective refractory period; VF, ventricular fibrillation; defib, defibrillation; ECMO high, increasing of the ECMO flow to 80-100 mL/kg/min after onset of VF until the sinus rhythm was restored.

Mentions: A diagnostic decapolar catheter (Response CSL, St. Jude Medical, USA) was inserted under fluoroscopic guidance into the apex of the right ventricle (RV) via right jugular vein to provide monitoring of intracardial electrograms and to induce VF. Five bipolar channels were recorded from the apex to base of RV at 3 kHz sampling rate. VF was induced by programmed ventricular stimulation (PVS, Figure 2). Briefly, electrical stimuli (12 ms duration, maximal stimulation current 20 mA) were delivered from the apex of RV. Eight basic stimuli (S1) of cycle length 300, 350 or 400 ms according to the heart rate were coupled with up to 4 extrastimuli (S2-S5). The coupling interval of S2 was decreased at 10 ms steps until the ventricular effective refractory period (ERP) was achieved. S2 coupling interval was then set to 10 ms above ERP and analogically S3 or S4 stimuli were delivered until VF was reached. There were at least 10 s intervals between pacing sequences. VF was defined as an orderless rhythm without detectable QRS complexes lasting longer than 30 s. Normal SR was restituted by the transcutaneous defibrillation using pads placed in the conventional position sternum - apex (TEC-5521, Nihon Kohden, Japan). Biphasic shocks with rising energy (150-200-270 J) were delivered as needed. Another PVS procedure was performed at least 10 minutes after SR restoration in a previous one.Figure 2


Renal denervation decreases effective refractory period but not inducibility of ventricular fibrillation in a healthy porcine biomodel: a case control study.

Lubanda JC, Kudlicka J, Mlcek M, Chochola M, Neuzil P, Linhart A, Kittnar O - J Transl Med (2015)

Scheme of electrophysiological study. 8xS1 indicates the train of eight basic stimuli; S2-5, up to five extrastimuli; ERP, effective refractory period; VF, ventricular fibrillation; defib, defibrillation; ECMO high, increasing of the ECMO flow to 80-100 mL/kg/min after onset of VF until the sinus rhythm was restored.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4300561&req=5

Fig2: Scheme of electrophysiological study. 8xS1 indicates the train of eight basic stimuli; S2-5, up to five extrastimuli; ERP, effective refractory period; VF, ventricular fibrillation; defib, defibrillation; ECMO high, increasing of the ECMO flow to 80-100 mL/kg/min after onset of VF until the sinus rhythm was restored.
Mentions: A diagnostic decapolar catheter (Response CSL, St. Jude Medical, USA) was inserted under fluoroscopic guidance into the apex of the right ventricle (RV) via right jugular vein to provide monitoring of intracardial electrograms and to induce VF. Five bipolar channels were recorded from the apex to base of RV at 3 kHz sampling rate. VF was induced by programmed ventricular stimulation (PVS, Figure 2). Briefly, electrical stimuli (12 ms duration, maximal stimulation current 20 mA) were delivered from the apex of RV. Eight basic stimuli (S1) of cycle length 300, 350 or 400 ms according to the heart rate were coupled with up to 4 extrastimuli (S2-S5). The coupling interval of S2 was decreased at 10 ms steps until the ventricular effective refractory period (ERP) was achieved. S2 coupling interval was then set to 10 ms above ERP and analogically S3 or S4 stimuli were delivered until VF was reached. There were at least 10 s intervals between pacing sequences. VF was defined as an orderless rhythm without detectable QRS complexes lasting longer than 30 s. Normal SR was restituted by the transcutaneous defibrillation using pads placed in the conventional position sternum - apex (TEC-5521, Nihon Kohden, Japan). Biphasic shocks with rising energy (150-200-270 J) were delivered as needed. Another PVS procedure was performed at least 10 minutes after SR restoration in a previous one.Figure 2

Bottom Line: According to histological findings, RDN procedure was successfully performed in all biomodels.RDN decreased the influence of sympathetic nerve system on the heart conduction system in healthy porcine biomodel.However, the electrophysiological study was not associated with a decrease of VF inducibility after RDN.

View Article: PubMed Central - PubMed

Affiliation: 2nd Department of Medicine - Department of Cardiovascular Medicine, First Faculty of Medicine, Charles University in Prague and General University Hospital in Prague, U Nemocnice 2, Prague 2, 128 00, Czech Republic. jean-claude.lubanda@vfn.cz.

ABSTRACT

Background: Ventricular arrhythmias play an important role in cardiovascular mortality especially in patients with impaired cardiac and autonomic function. The aim of this experimental study was to determine, if renal denervation (RDN) could decrease the inducibility of ventricular fibrillation (VF) in a healthy porcine biomodel.

Methods: Controlled electrophysiological study was performed in 6 biomodels 40 days after RDN (RDN group) and in 6 healthy animals (control group). The inducibility of VF was tested by programmed ventricular stimulation from the apex of right ventricle (8 basal stimuli coupled with up to 4 extrastimuli) always three times in each biomodel using peripheral extracorporeal oxygenation for hemodynamic support. Further, basal heart rate (HR), PQ and QT intervals and effective refractory period of ventricles (ERP) were measured. Technical success of RDN was evaluated by histological examination.

Results: According to histological findings, RDN procedure was successfully performed in all biomodels. Comparing the groups, basal HR was lower in RDN group: 79 (IQR 58; 88) vs. 93 (72; 95) beats per minute (p = 0.003); PQ interval was longer in RDN group: 145 (133; 153) vs. 115 (113; 120) ms (p < 0.0001) and QTc intervals were comparable: 402 (382; 422) ms in RDN vs. 386 (356; 437) ms in control group (p = 0.1). ERP was prolonged significantly in RDN group: 159 (150; 169) vs. 140 (133; 150) ms (p = 0.001), but VF inducibility was the same (18/18 vs. 18/18 attempts).

Conclusions: RDN decreased the influence of sympathetic nerve system on the heart conduction system in healthy porcine biomodel. However, the electrophysiological study was not associated with a decrease of VF inducibility after RDN.

No MeSH data available.


Related in: MedlinePlus