The application of brief high voltage electrical pulses to tissue can lead to an irreversible or reversible electroporation effect in a cell-specific manner. In the management of ventricular ...arrhythmias, the ability to target different tissue types, specifically cardiac conduction tissue (His-Purkinje System) vs. cardiac myocardium would be advantageous. We hypothesize that pulsed electric fields (PEFs) can be applied safely to the beating heart through a catheter-based approach, and we tested whether the superficial Purkinje cells can be targeted with PEFs without injury to underlying myocardial tissue.
In an acute (n = 5) and chronic canine model (n = 6), detailed electroanatomical mapping of the left ventricle identified electrical signals from myocardial and overlying Purkinje tissue. Electroporation was effected via percutaneous catheter-based Intracardiac bipolar current delivery in the anesthetized animal. Repeat Intracardiac electrical mapping of the heart was performed at acute and chronic time points; followed by histological analysis to assess effects.
PEF demonstrated an acute dose-dependent functional effect on Purkinje, with titration of pulse duration and/or voltage associated with successful acute Purkinje damage. Electrical conduction in the insulated bundle of His (n = 2) and anterior fascicle bundle (n = 2), was not affected. At 30 days repeat cardiac mapping demonstrated resilient, normal electrical conduction throughout the targeted area with no significant change in myocardial amplitude (pre 5.9 ± 1.8 mV, 30 days 5.4 ± 1.2 mV, p = 0.92). Histopathological analysis confirmed acute Purkinje fiber targeting, with chronic studies showing normal Purkinje fibers, with minimal subendocardial myocardial fibrosis.
PEF provides a novel, safe method for non-thermal acute modulation of the Purkinje fibers without significant injury to the underlying myocardium. Future optimization of this energy delivery is required to optimize conditions so that selective electroporation can be utilized in humans the treatment of cardiac disease.
Background
Transvenous lead implantation has multiple drawbacks and complications that can be overcome by epicardial lead placement. We aimed to design percutaneously implanted epicardial leads that ...are anchored through the transverse sinus (TS).
Methods and results
We designed a novel multielectrode pacing device with four bipole electrode pairs. The device is advanced through the TS, with both ends externalized out of the pericardium. We tested the prototype in one proof‐of‐concept and 5 additional acute canine experiments.
The TS device recorded ventricular and atrial electrograms. The median amplitude of near‐field ventricular electrograms was 3.3 mA (IQR 2.0–4.3) and of near‐field atrial electrograms was 2.1 mA (IQR 1.3–2.2). The median ventricular threshold (N = 30) was 1.1 mA (IQR 0.7–3.1) at a median pulse width of 0.5 ms (IQR 0.5–0.5). The median atrial threshold (N = 10) was 2.4 mA (IQR 1.1–7.8) at a median pulse width of 0.5 ms (IQR 0.5–0.9). Right and left ventricular and atrial pacing morphologies were noted while pacing electrodes adjacent to these chambers. Simultaneous left (LV) and right ventricular (RV) pacing showed reduction in QRS duration from 116 ms (RV) and 105 ms (LV) to 91 ms. On necropsy, the device was located in the TS in all animals. There were TS abrasions in one animal, and no other acute complications.
Conclusions
This study highlights a novel approach to epicardial pacing harnessing the unique anatomy of the transverse sinus as an anchoring point. Placement of this novel transverse sinus device was safe and feasible, with acceptable atrial and ventricular thresholds.
Purpose
Electroanatomic mapping (EAM) has been utilized as a modality to improve the sensitivity of endomyocardial biopsy (EMB). We sought to systematically review published medical literature on the ...efficacy and safety of EAM-guided EMB.
Methods
We searched Ovid MEDLINE, Ovid Embase, Ovid CDR, Cochrane Central, Scopus, and Web of Science for studies where EAM was used for EMB. Data abstracted included demographics, indications, final diagnoses, histology findings, and technical details of biopsy extraction. Test characteristics including sensitivity (Se), specificity (Sp), and area under curve (AUC) were calculated on a per-patient and per-biopsy level.
Results
Seventeen studies (9 case series, 8 case reports) were included in this systematic review. EAM-guided EMB was performed in 148 patients and results of 207 individual biopsies were available for analysis. The most common indications for EAM-guided EMB were suspected arrhythmogenic right ventricular cardiomyopathy (ARVC), myocarditis, and cardiac sarcoidosis (CS). The pooled sensitivity and specificity for EAM-guided EMB for the diagnosis of cardiomyopathies (ARVC, myocarditis, CS, and other specific diagnoses) were 92 and 58% on per-biopsy analysis and 100 and 39% on per-patient analysis. Among the individual components of abnormal EGMs, abnormal unipolar EGM had the best AUC on per-biopsy (0.81, 95% CI 0.68–0.90) and per-patient analysis (0.84, 95% CI 0.68–0.92). EAM-guided EMB appears safe. Adverse events included 1 hemopericardium, 2 minimal asymptomatic pericardial effusions, and 1 femoral hematoma.
Conclusions
EAM-guided EMB is a safe and efficacious method and might improve test characteristics over conventional fluoroscopy-guided biopsy.
Introduction
Emerging medical technology has allowed for monitoring of heart rhythm abnormalities using smartphone compatible devices. The safety and utility of such devices have not been established ...in patients with cardiac implantable electronic devices (CIEDs). We sought to assess the safety and compatibility of the Food and Drug Administration‐approved AliveCor Kardia device in patients with CIEDs.
Methods and Results
We prospectively recruited patients with CIED for a Kardia recording during their routine device interrogation. A recording was obtained in paced and nonpaced states. Adverse clinical events were noted at the time of recording. Electrograms (EGMs) from the cardiac device were obtained at the time of recording to assess for any electromagnetic interference (EMI) introduced by Kardia. Recordings were analyzed for quality and given a score of 3 (interpretable rhythm, no noise), 2 (interpretable rhythm, significant noise) or 1 (uninterpretable). A total of 251 patients were recruited (59% with a pacemaker and 41% with ICD). There were no adverse clinical events noted at the time of recording and no changes to CIED settings. Review of all EGMs revealed no EMI introduced by Kardia. Recordings were correctly interpreted in 90% of paced recordings (183 had a score of 3, 43 of 2, and 25 of 1) and 94.7% of nonpaced recordings (147 of 3, 15 of 2, and 9 of 1).
Conclusion
The AliveCor Kardia device has an excellent safety profile when used in conjunction with most CIEDs. The quality of recordings was preserved in this population. The device, therefore, can be considered for heart rhythm monitoring in patients with CIEDs.
Burden of arrhythmia in hospitalized HIV patients Abudan, Anas A.; Vaidya, Vaibhav R.; Tripathi, Byomesh ...
Clinical cardiology (Mahwah, N.J.),
January 2021, Letnik:
44, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Background
The improved life expectancy observed in patients living with human immunodeficiency virus (HIV) infection has made age‐related cardiovascular complications, including arrhythmias, a ...growing health concern.
Hypothesis
We describe the temporal trends in frequency of various arrhythmias and assess impact of arrhythmias on hospitalized HIV patients using the Nationwide Inpatient Sample (NIS).
Methods
Data on HIV‐related hospitalizations from 2005 to 2014 were obtained from the NIS database using International Classification of Diseases, 9th Revision (ICD‐9) codes. Data was further subclassified into hospitalizations with associated arrhythmias and those without. Baseline demographics and comorbidities were determined. Outcomes including in‐hospital mortality, cost of care, and length of stay were extracted. SAS 9.4 (SAS Institute Inc., Cary, NC) was utilized for analysis. A multivariable analysis was performed to identify predictors of arrhythmias among hospitalized HIV patients.
Results
Among 2 370 751 HIV‐related hospitalizations identified, the overall frequency of any arrhythmia was 3.01%. Atrial fibrillation (AF) was the most frequent arrhythmia (2110 per 100 000). The overall frequency of arrhythmias increased over time by 108%, primarily due to a 132% increase in AF. Arrhythmias are more frequent among older males, lowest income quartile, and nonelective admissions. Patients with arrhythmias had a higher in‐hospital mortality rate (9.6%). In‐hospital mortality among patients with arrhythmias decreased over time by 43.8%. The cost of care and length of stay associated with arrhythmia‐related hospitalizations were mostly unchanged.
Conclusions
Arrhythmias are associated with significant morbidity and mortality in hospitalized HIV patients. AF is the most frequent arrhythmia in hospitalized HIV patients.
Background
Atrial fibrillation ablation results in microbubbles and particulate emboli formation. We aimed to develop and test the early feasibility of a novel ablation hood to contain microbubbles ...and particulate emboli with the ultimate goal of preventing systemic embolization.
Methods
In seven canines, we developed, iterated, and tested a novel retractable hood that can cover the catheter-tissue ablation site. The number and volume (nL) of microbubbles formed during ablation with and without the hood was measured using an extracorporeal circulation loop. Wilcoxon’s signed-rank test was used to compare the number of bubbles detected with and without the hood.
Results
The hood reduced systemic embolization of microbubbles in 21/28 (75%) of ablations. Both atrial and ventricular ablations showed a statistically significant reduction in bubble number (476 ± 811 without hood vs 173 ± 226 with hood,
p
= 0.02; 2669 ± 1623 without hood vs 1417 ± 970 with hood,
p
= 0.04, respectively) and bubble volume (3.3 ± 7.6 nL without hood vs 0.2 ± 0.56 nL with hood,
p
= 0.006; 6.1 ± 5.2 nL without hood vs 1.9 ± 1.4 nL with hood,
p
= 0.05, respectively).
Conclusions
Use of a novel hood to cover the ablation catheter at the site of catheter-tissue contact has the potential to provide a means to reduce systematic embolization of microbubbles. Further work is required to examine particulate emboli, but these data show the early feasibility of this design concept.
Purpose
Epicardial ablation and mapping are critical adjuncts to the electrophysiologist’s approach to arrhythmias; however, ablation within the epicardial space requires the avoidance of coronary ...arteries (CA). We aimed to evaluate the feasibility and performance of a novel-stabilizing ablation sheath housing an intracardiac echocardiography (ICE) catheter to (1) obtain Epicardial Echocardiography (EE) images, (2) visualize CAs, and (3) enable targeted delivery of radiofrequency energy away from visualized CAs.
Methods
We designed a sheath that could enclose a regular ICE catheter. This sheath has flanges and a balloon, with three interspersed windows surrounded by an electrode. In an acute canine model (
N
= 6), the sheath was manipulated within the pericardial space to visualize cardiac structures and CAs. Visualization of CAs was confirmed with angiography. Ablation was then performed through the window either proximal or distal to the CA.
Results
The novel sheath was successfully deployed in six canines, with no acute procedural complications. Images with an excellent spatial resolution of cardiac structures were obtained including the right ventricular outflow tract; aortic, pulmonary, and mitral valves; and left atrial appendage. CAs were successfully visualized, and ablation from a sheath window either proximal or distal to the CA did not produce angiographic or histopathological evidence of CA damage despite evidence of acute injury to the adjacent ablated myocardium.
Conclusions
This novel percutaneous stabilizing sheath was able to successfully obtain high-quality EE images as well as provide a non-fluoroscopic intra-procedural means to visualize CAs. Use of this sheath enabled successful delivery of energy to avoided CA damage.
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