Cardiac Purkinje fibers and arrhythmias; The GK Moe Award Lecture 2015

Boyden, Penelope A.; Dun, Wen; Robinson, Richard B.

doi:10.1016/j.hrthm.2016.01.011

Cited by 39 publications

(43 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Contemporary modalities are typically composed of point‐by‐point radiofrequency or cryotherapy ablation for ventricular arrhythmia ablation. Given the incredible redundancy and arborizing nature of Purkinje fibers,23 coupled with the trabeculated nature of the left ventricle, an approach using electroporation may be a promising alternative. Consistent with other noncardiac electroporation patterns of injury, the extent of injury found was not solely reliant on contact and confined to the tissue adjacent to the catheter tip, but a result of the electric field (V/cm) created 24, 25, 26, 27.…”

Section: Discussionmentioning

confidence: 99%

Elimination of Purkinje Fibers by Electroporation Reduces Ventricular Fibrillation Vulnerability

Livia

Sugrue

Witt

et al. 2018

JAHA

View full text Add to dashboard Cite

BackgroundThe Purkinje network appears to play a pivotal role in the triggering as well as maintenance of ventricular fibrillation. Irreversible electroporation (IRE) using direct current has shown promise as a nonthermal ablation modality in the heart, but its ability to target and ablate the Purkinje tissue is undefined. Our aim was to investigate the potential for selective ablation of Purkinje/fascicular fibers using IRE.Methods and ResultsIn an ex vivo Langendorff model of canine heart (n=8), direct current was delivered in a unipolar manner at various dosages from 750 to 2500 V, in 10 pulses with a 90‐μs duration at a frequency of 1 Hz. The window of ventricular fibrillation vulnerability was assessed before and after delivery of electroporation energy using a shock on T‐wave method. IRE consistently eradicated all Purkinje potentials at voltages between 750 and 2500 V (minimum field strength of 250–833 V/cm). The ventricular electrogram amplitude was only minimally reduced by ablation: 0.6±2.3 mV (P=0.03). In 4 hearts after IRE delivery, ventricular fibrillation could not be reinduced. At baseline, the lower limit of vulnerability to ventricular fibrillation was 1.8±0.4 J, and the upper limit of vulnerability was 19.5±3.0 J. The window of vulnerability was 17.8±2.9 J. Delivery of electroporation energy significantly reduced the window of vulnerability to 5.7±2.9 J (P=0.0003), with a postablation lower limit of vulnerability=7.3±2.63 J, and the upper limit of vulnerability=18.8±5.2 J.ConclusionsOur study highlights that Purkinje tissue can be ablated with IRE without any evidence of underlying myocardial damage.

show abstract

Section: Discussionmentioning

confidence: 99%

Elimination of Purkinje Fibers by Electroporation Reduces Ventricular Fibrillation Vulnerability

Livia

Sugrue

Witt

et al. 2018

JAHA

View full text Add to dashboard Cite

show abstract

“…1 Similarly, SKNA was recorded in 5.9% of the windows, whereas it was recorded more than 12.5% of time in a canine study. 17 This difference might be explained by the timing of recordings. In ambulatory animals, 14 we found that the stellate ganglion nerve activities were infrequently observed in the first few days after surgery but became very frequent one week later.…”

Section: Discussionmentioning

confidence: 99%

Simultaneous recordings of intrinsic cardiac nerve activity and skin sympathetic nerve activity from human patients during the postoperative period

et al. 2017

View full text Add to dashboard Cite

Background Intrinsic cardiac nerve activities (ICNA) and the skin nerve activities (SKNA) are both associated with cardiac arrhythmias in dogs. Objective To test the hypothesis that ICNA and SKNA correlate with postoperative cardiac arrhythmias in humans. Methods Eleven patients (60±13 years old; 4 female) were enrolled in this study. Electrical signals were simultaneously recorded from electrocardiogram (ECG) patch electrodes on the chest wall and from two temporary pacing wires placed during open heart surgery on the left atrial epicardial fat pad. The signals were filtered to display SKNA and ICNA. Premature atrial contractions (PAC) and premature ventricular contractions (PVC) were manually determined. The SKNA and ICNA of the first 300 min of each patient were calculated min-by-min to determine baseline average amplitudes of nerve activities and to determine their correlation with arrhythmia burden. Results We processed 1365±973 min of recording per patient. Low-amplitude SKNA and ICNA were present at all time, while the burst discharges were observed much less frequently. Both SKNA and burst ICNA were significantly associated with the onset of PACs and PVCs. Baseline average ICNA (aICNA), but not SKNA (aSKNA), had a significant association with PAC burden. The correlation coefficient (r) between aICNA and PAC burden was 0.78 (P<0.01). A patient with the greatest aICNA developed postoperative atrial fibrillation. Conclusions ICNA and SKNA can be recorded from human patients in the postoperative period. Baseline magnitude of ICNA correlates with PAC burden and development of postoperative atrial fibrillation.

show abstract

“…Figure 1 shows the endocardial pseudotendon of a normal rabbit ventricle (Figure 1A), a PC (Figure 1B), and a VM (Figure 1C). A PC was identified by its tapered cell morphology and a lack of transverse tubules 10. PCs and VMs were selected for patch studies.…”

Section: Resultsmentioning

confidence: 99%

“…However, others showed that cardiac PCs and working myocytes share a common myogenic precursor and that migratory neuroectoderm‐derived populations do not contribute to the development of PCs 24, 25. While there is no consensus on the neuronal origin of the PCs, there is little doubt that the PCs are electrophysiologically different than the working VMs 10. Compared with VMs, the PCs have much smaller inward rectifier K+ current and much larger Ca 2+ ‐independent transient outward K + current 26.…”

Section: Discussionmentioning

confidence: 99%

“…The availability of repolarization currents is important in subsequent depolarization and rapid conduction through the His‐Purkinje system. In addition to conduction, PCs are also important in the initiation and maintenance of ventricular arrhythmias 9, 10. PCs have an increased intracellular calcium‐membrane potential coupling gain and are sources of afterdepolarization and triggered activity in rabbit ventricles 11.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Small‐Conductance Calcium‐Activated Potassium Current in Normal Rabbit Cardiac Purkinje Cells

Reher

Wang

Hsueh

et al. 2017

JAHA

View full text Add to dashboard Cite

BackgroundPurkinje cells (PCs) are important in cardiac arrhythmogenesis. Whether small‐conductance calcium‐activated potassium (SK) channels are present in PCs remains unclear. We tested the hypotheses that subtype 2 SK (SK2) channel proteins and apamin‐sensitive SK currents are abundantly present in PCs.Methods and ResultsWe studied 25 normal rabbit ventricles, including 13 patch‐clamp studies, 4 for Western blotting, and 8 for immunohistochemical staining. Transmembrane action potentials were recorded in current‐clamp mode using the perforated‐patch technique. For PCs, the apamin (100 nmol/L) significantly prolonged action potential duration measured to 80% repolarization by an average of 10.4 ms (95% CI, 0.11–20.72) (n=9, P=0.047). Voltage‐clamp study showed that apamin‐sensitive SK current density was significantly larger in PCs compared with ventricular myocytes at potentials ≥0 mV. Western blotting of SK2 expression showed that the SK2 protein expression in the midmyocardium was 58% (P=0.028) and the epicardium was 50% (P=0.018) of that in the pseudotendons. Immunostaining of SK2 protein showed that PCs stained stronger than ventricular myocytes. Confocal microscope study showed SK2 protein was distributed to the periphery of the PCs.Conclusions SK2 proteins are more abundantly present in the PCs than in the ventricular myocytes of normal rabbit ventricles. Apamin‐sensitive SK current is important in ventricular repolarization of normal PCs.

show abstract

Cardiac Purkinje fibers and arrhythmias; The GK Moe Award Lecture 2015

Cited by 39 publications

References 38 publications

Elimination of Purkinje Fibers by Electroporation Reduces Ventricular Fibrillation Vulnerability

Elimination of Purkinje Fibers by Electroporation Reduces Ventricular Fibrillation Vulnerability

Simultaneous recordings of intrinsic cardiac nerve activity and skin sympathetic nerve activity from human patients during the postoperative period

Small‐Conductance Calcium‐Activated Potassium Current in Normal Rabbit Cardiac Purkinje Cells

Contact Info

Product

Resources

About