Sevoflurane Has No Effect on Sinoatrial Node Function or on Normal Atrioventricular and Accessory Pathway Conduction in Wolff-Parkinson-White Syndrome during Alfentanil/Midazolam Anesthesia 

1999 ◽  
Vol 90 (1) ◽  
pp. 60-65 ◽  
Author(s):  
Michael D. Sharpe ◽  
Daniel J. Cuillerier ◽  
John K. Lee ◽  
Magdi Basta ◽  
Andrew D. Krahn ◽  
...  
Keyword(s):  
Cycle Length ◽  
Sinoatrial Node ◽  
Sinus Node ◽  
Accessory Pathway ◽  
Atrioventricular Node ◽  
Conduction Time ◽  
White Syndrome ◽  
The Right ◽  
Ablative Procedures ◽  
Wolff Parkinson White Syndrome

Background The effects of sevoflurane on the electrophysiologic properties of the human heart are unknown. This study evaluated the effects of sevoflurane on the electrophysiologic properties of the normal atrioventricular conduction system, and on the accessory pathways in patients with Wolff-Parkinson-White syndrome, to determine its suitability as an anesthetic agent for patients undergoing ablative procedures. Methods Fifteen patients with Wolff-Parkinson-White syndrome undergoing elective radiofrequency catheter ablation were studied. Anesthesia was induced with alfentanil (20-50 microg/kg) and midazolam (0.15 mg/kg), and vecuronium (20 mg) and maintained with alfentanil (0.5 to 2 microg x kg(-1) x min(-1)) and midazolam (1 or 2 mg every 10-15 min, as required). An electrophysiologic study measured the effective refractory period of the right atrium, atrioventricular node, and accessory pathway; the shortest conducted cycle length of the atrioventricular node and accessory pathway during atrial pacing; the effective refractory period of the right ventricle and accessory pathway; and the shortest retrograde conducted cycle length of the accessory pathway during ventricular pacing. Parameters of sinoatrial node function included sinus node recovery time, corrected sinus node recovery time, and sinoatrial conduction time. Intraatrial conduction time and the atrial-His interval were also measured. Characteristics of induced reciprocating tachycardia, including cycle length, atrial-His, His-ventricular, and ventriculoatrial intervals, also were measured. Sevoflurane was administered to achieve an end-tidal concentration of 2% (1 minimum alveolar concentration), and the study measurements were repeated. Results Sevoflurane had no effect on the electrophysiologic parameters of conduction in the normal atrioventricular conduction system or accessory pathway, or during reciprocating tachycardia. However, sevoflurane caused a statistically significant reduction in the sinoatrial conduction time and atrial-His interval but these changes were not clinically important. All accessory pathways were successfully identified and ablated. Conclusions Sevoflurane had no effect on the electrophysiologic nature of the normal atrioventricular or accessory pathway and no clinically important effect on sinoatrial node activity. It is therefore a suitable anesthetic agent for patients undergoing ablative procedures.

Propofol Has No Direct Effect on Sinoatrial Node Function or on Normal Atrioventricular and Accessory Pathway Conduction in Wolff-Parkinson-White Syndrome during Alfentanil/Midazolam Anesthesia

1995 ◽  
Vol 82 (4) ◽  
pp. 888-895. ◽  
Author(s):  
Michael D. Sharpe ◽  
Wojciech B. Dobkowski ◽  
John M. Murkin ◽  
George Klein ◽  
Raymond Yee
Keyword(s):  
Refractory Period ◽  
Cycle Length ◽  
Accessory Pathway ◽  
Right Atrial ◽  
Conduction Time ◽  
Av Node ◽  
White Syndrome ◽  
Sa Node ◽  
The Right ◽  
Wolff Parkinson White Syndrome

Background Propofol has been implicated as causing intraoperative bradyarrhythmias. Furthermore, the effects of propofol on the electrophysiologic properties of the sinoatrial (SA) node and on normal atrioventricular (AV) and accessory pathways in patients with Wolff-Parkinson-White syndrome are unknown. Therefore, this study examined the effects of propofol on the cardiac electrophysiologic properties in humans to determine whether propofol promotes bradyarrhythmias and its suitability as an anesthetic agent in patients undergoing ablative procedures. Methods Twelve patients with Wolff-Parkinson-White syndrome undergoing radiofrequency catheter ablation were studied. Anesthesia was induced with alfentanil (50 micrograms/kg), midazolam (0.15 mg/kg), and vecuronium (20 mg) and maintained with alfentanil (2 micrograms.kg-1.min-1) and midazolam (1-2 mg, every 15 min, as needed). A electrophysiologic study was performed consisting of measurement of the effective refractory period of the right atrium, AV node, and accessory pathway and the shortest cycle length of the AV node and accessory pathway during antegrade stimulation plus the effective refractory period of the right ventricle and accessory pathway and the shortest cycle length of the accessory pathway during retrograde stimulation. Determinants of SA node function including sinus node recovery time, corrected sinus node recovery time, and SA conduction time; intraatrial conduction time and atrial-His interval also were measured. Reciprocating tachycardia was induced by rapid right atrial or ventricular pacing, and the cycle length and atrial-His, His-ventricular, and ventriculoatrial intervals were measured. Alfentanil/midazolam was then discontinued. Propofol was administered (bolus 2 mg/kg + 120 micrograms.kg-1.min-1), and the electrophysiologic measurements were repeated. Results Propofol caused a statistically significant but clinically unimportant prolongation of the right atrial refractory period. The effective refractory periods of the AV node, right ventricle, and accessory pathway, as well as the shortest cycle length, were not affected. Parameters of SA node function and intraatrial conduction also were not affected. Sustained reciprocating tachycardia was inducible in 8 of 12 patients, and propofol had no effect on its electrophysiologic properties. All accessory pathways were successfully identified and ablated. Conclusions Propofol has no clinically significant effect on the electrophysiologic expression of the accessory pathway and the refractoriness of the normal AV conduction system. In addition, propofol has no direct effect on SA node activity or intraatrial conduction; therefore, it does not directly induce bradyarrhythmias. It is thus a suitable agent for use in patients undergoing ablative procedures who require either a neuroleptic or general anesthetic.

Vagally induced hyperpolarization in atrioventricular node

1986 ◽  
Vol 251 (3) ◽  
pp. H631-H643 ◽  
Author(s):  
T. Mazgalev ◽  
L. S. Dreifus ◽  
E. L. Michelson ◽  
A. Pelleg
Keyword(s):  
Action Potentials ◽  
Cycle Length ◽  
Time Course ◽  
Vagal Stimulation ◽  
Sinus Node ◽  
Atrioventricular Node ◽  
Conduction Time ◽  
Sinus Cycle Length ◽  
Atrioventricular Nodal Conduction ◽  
The Moment

The effects of postganglionic vagal stimulation on atrioventricular nodal conduction were studied in 12 rabbit atrial-atrioventricular nodal preparations. Vagal stimulation was introduced in the sinus and atrioventricular nodes, separately or in combination, using single bursts of subthreshold stimuli. The sinus cycle length was scanned to identify the phasic effect of vagal stimulation. Action potentials from cells in the AN, N, and NH regions of the atrioventricular node were recorded by microelectrode techniques. Vagally induced hyperpolarization of cells in the atrioventricular node resulted in a phase-dependent prolongation of conduction time and reflected the level of residual hyperpolarization at the moment of arrival of the next atrial beat at the atrioventricular nodal input region. Vagally induced hyperpolarization was membrane potential dependent, although its overall time course was similar at different phases. Increased diastolic depolarization followed the maximal hyperpolarization. This "rebound" observed at certain phases was responsible for paradoxical shortening of the conduction time after vagal stimulation. The predominant effects of local vagal stimulation in the atrioventricular node were observed in cells in or near the N region. Slower rate of rise, shorter amplitude and duration, as well as step formations were among the changes in action potentials recorded from these cells. The effects of vagal stimulation were inhomogeneous between different regions of the atrioventricular node as well as within the N region, producing alternative pathways of conduction and the potential for reentry. The concomitant changes in sinus cycle length resulting from vagal stimulation in the sinus node region altered the phasic effects of vagal stimulation introduced in the atrioventricular node. This was related to a direct influence of the prolonged sinus cycle length on atrioventricular nodal refractoriness as well as an indirect effect on the degree of residual vagally induced hyperpolarization at the moment of arrival of the delayed atrial beat. These findings provide mechanistic explanations for the complex effects of vagal stimulation on atrioventricular nodal conduction.

Modulation of electrophysiological properties of neonatal canine heart by tonic parasympathetic stimulation

1990 ◽  
Vol 258 (1) ◽  
pp. H38-H44 ◽  
Author(s):  
A. S. Pickoff ◽  
A. Stolfi
Keyword(s):  
Cycle Length ◽  
Parasympathetic Nervous System ◽  
Vagal Stimulation ◽  
Sinus Node ◽  
Right Atrial ◽  
Conduction Time ◽  
Canine Heart ◽  
Electrophysiological Properties ◽  
Refractory Periods ◽  
The Right

The effects of tonic right and left vagal stimulation (RVS and LVS) on electrophysiological properties of the immature myocardium and specialized conduction system were evaluated in 11 neonatal canines pretreated with propranolol (1 mg/kg iv). Electrophysiological studies were performed by recording intracardiac electrograms from multiple endocardial catheters during programmed electrical stimulation. Assessments were made of sinus node function, intra-atrial, atrioventricular (AV) nodal and His-Purkinje conduction, and atrial and ventricular refractoriness in the control state and during RVS and LVS at 4–12 Hz. Vagal stimulation prolonged the sinus cycle length; RVS produced a 38% increase and LVS a 25% increase at 8 Hz (P less than 0.01). There were no changes in the intra-atrial or His-Purkinje conduction times. Comparable increases occurred during RVS and LVS in the paced cycle length resulting in AV nodal Wenckebach, the AV nodal conduction time at a paced cycle length of 340 ms, and the effective and functional refractory periods of the AV node, suggesting symmetrical influences of the right and left vagus on neonatal AV nodal function. Right atrial effective and functional refractory periods shortened significantly during vagal stimulation (ERP, 36% RVS and 23% LVS; FRP, 27% RVS and 15% LVS), and in 5 of 11 neonates, a sustained regular atrial tachyarrhythmia was induced during atrial extra-stimulation. Small yet significant increases were observed in the right ventricular ERP and FRP during vagal stimulation. This study provides information regarding the functional integrity of the parasympathetic nervous system and its potential role as a modulator of the electrophysiological properties of the newborn heart.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Use of 3D mapping system for ablating an accessory pathway associated with coronary sinus diverticulum

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Mohammad Paymard ◽  
Marc W. Deyell ◽  
Santabhanu Chakrabarti ◽  
Zachary W. Laksman ◽  
Jacob Larsen ◽  
...  
Keyword(s):  
Coronary Sinus ◽  
Accessory Pathway ◽  
Three Dimensional ◽  
Radiofrequency Energy ◽  
Cardiac Mapping ◽  
Unsuccessful Attempt ◽  
White Syndrome ◽  
Mapping System ◽  
Coronary Sinus Diverticulum ◽  
Wolff Parkinson White Syndrome

Abstract Background This is a rare and challenging case of Wolff–Parkinson–White syndrome due to a posteroseptal accessory pathway located in the coronary sinus diverticulum. It is often difficult to precisely locate this type of accessory pathway, and the ablation procedure could be associated with collateral damage to the neighbouring coronary arteries. Case Presentation The patient was a 49-year-old female with Wolff–Parkinson–White syndrome who was referred for catheter ablation. She had had a previous unsuccessful attempt at ablation and had remained symptomatic despite drug therapy. The pre-procedural cardiac computed tomography scan revealed the presence of a diverticulum in the proximal coronary sinus. Using an advanced three-dimensional cardiac mapping system, the electroanatomic map of the diverticulum was created. The accessory pathway potential was identified within the diverticulum preceding the ventricular insertion. The accessory pathway was then successfully ablated using radiofrequency energy. Conclusion We have demonstrated that the advanced three-dimensional cardiac mapping system plays a very important role in guiding clinicians in order to precisely locate and safely ablate this type of challenging accessory pathway.

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