scholarly journals A Circular Multielectrode Pulsed-Field Ablation Catheter "Lasso PFA": Lesion Characteristics, Durability and Effect on Neighboring Structures

2021 ◽  
Author(s):  
Hagai Yavin ◽  
Erez Brem ◽  
Israel Zilberman ◽  
Ayelet Shapira-Daniels ◽  
Keshava Datta ◽  
...  
Keyword(s):  
Phrenic Nerve ◽  
High Intensity ◽  
Vena Cava ◽  
Muscularis Propria ◽  
Nerve Tissue ◽  
Right Atrial ◽  
Histopathological Analysis ◽  
Nerve Paralysis ◽  
Pulsed Field ◽  
Ablation Line

Background - Pulsed field ablation (PFA) is a nonthermal energy with potential safety advantages over radiofrequency ablation (RFA). This study investigated a novel PFA system- a circular multielectrode catheter ("PFA lasso") and a multichannel generator designed to work with Carto 3® mapping system. Methods - A 7.5F bidirectional circular catheter with 10 electrodes and variable expansion was designed for PFA (biphasic, 1800 Volts). This study included a total of 16 swine utilized to investigate the following 3 experimental aims: Aim 1 examined the feasibility to create a right atrial ablation line of block from the superior vena cava (SVC) to the inferior vena cava (IVC). Aim 2 examined the effect of PFA on lesion maturation including durability after a 30-day survival period. Aim 3 examined the effect of high intensity PFA (10 applications) on esophageal and phrenic nerve tissue in comparison to normal intensity RFA (1-2 applications). Histopathological analysis of all cardiac, esophageal and phrenic nerve tissue was performed. Results - Acute line of block was achieved in 12/12 swine (100%) and required a total PFA time of 14 sec (IQR:9-24.5) per line. Ablation line durability after 28&3 days was maintained in 11/12 (91.7%) swine. PFA resulted in transmural lesions in 179/183 (97.8%) sections and a median lesion width of 14.2mm. High intensity PFA (9 [IQR:8-14] application) had no effect on the esophagus while standard intensity RFA (1.5 [IQR:1-2] applications) resulted in deep esophageal tissue injury involving the muscularis propria and adventitia layers. High intensity PFA (16 [IQR:10-28] applications) has no effect on phrenic nerve function and structure while standard dose RFA (1.5 [IQR:1-2] applications) resulted in acute phrenic nerve paralysis. Conclusions - In this preclinical model, a multielectrode circular catheter and multichannel generator produced durable atrial lesions with lower vulnerability to esophageal or phrenic nerve damage.

1207Pulsed Field Ablation: Acute and Chronic Safety and Lesion Efficacy

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
A Verma ◽  
D Haines ◽  
N Kirchhof ◽  
B Onal ◽  
M Martien ◽  
...  
Keyword(s):  
Phrenic Nerve ◽  
Cardiac Tissue ◽  
Superior Vena ◽  
Vena Cava ◽  
Preclinical Study ◽  
Atrial Appendage ◽  
Right Atrial ◽  
Collateral Damage ◽  
Cardiac Tissues ◽  
Electrical Isolation

Abstract Introduction Thermal ablation methods are the cornerstone of treatment for atrial fibrillation. However, they pose a risk to extra-cardiac structures and may result in inadequate efficacy. Nonthermal, pulsed-field ablation (PFA) delivery to cardiac tissues may create durable, efficacious lesions while avoiding collateral damage. Purpose The purpose of this preclinical GLP study was to assess acute and chronic electrical isolation combined with a pathology assessment of chronic lesion extent in response to PFA delivery to cardiac tissue, and to document any collateral damage. Methods Six pigs were treated with biphasic, bipolar PFA doses through a circular multi-electrode catheter. PFA was delivered at four locations at specified voltages: superior vena cava (SVC at 700V), right atrial appendage (RAA at 1500V), left atrial appendage (LAA at 1200V), and right pulmonary vein (RPV at 1500V). Phrenic nerve pacing thresholds and electrical block at SVC, RPV, and RAA sites were investigated acutely, and electrical block at the SVC sites chronically. Pigs were survived for 4 weeks. After euthanasia, necropsies and histopathological assessments documented the findings at the lesion sites and collateral tissues. Results Post PFA, entrance block was achieved in all SVC, RPV, and RAA sites. Histopathology showed characteristic replacement fibrosis of the myocardium at all ablation sites. The PFA lesions in the SVC and RPV were all continuously circumferential and histopathology did not detect any remaining myofiber conduits across the post-ablation fibrosis (consistent with the electrical assessments). PFA of the appendages caused wide-ranging fibrosis in the RAA, and limited fibrosis in the LAA. Histologically, the atrial fibrosis was almost exclusively transmural in both, with the RAA lesions overall diagnosed as circumferentially complete in all but one case. The right phrenic nerve (RPN) pacing thresholds were unchanged from baseline to the end of the procedure and were all <1.0V. The examined juxtaposed RPN segments exposed to PFA at the SVC and RPV sites were normal. None of the ablated targets was associated with stenosis, aneurysms, luminal thrombus or collateral damage on the abluminal side. Continuous lesion sites Conclusions This limited preclinical study evaluated the acute and chronic safety and efficacy of PFA in multiple cardiac and vascular treatment sites. In this porcine model, PFA results in acute and chronic electrical isolation, confirmed by pathology data, for all of the RPV and SVC targets. Pathology findings of the RAA revealed the ability to achieve chronic transmural lesions in highly trabeculated cardiac tissue. No collateral damage was seen to the adjacent RPN. Acknowledgement/Funding Medtronic

scholarly journals Evaluation of a Novel Cryoablation System: In vivo Testing in a Chronic Porcine Model

2012 ◽  
Vol 7 (6) ◽  
pp. 410-416 ◽  
Author(s):  
Timo Weimar ◽  
Anson M. Lee ◽  
Shuddhadeb Ray ◽  
Richard B. Schuessler ◽  
Ralph J. Damiano
Keyword(s):  
Cross Sections ◽  
Porcine Model ◽  
Vena Cava ◽  
Beating Heart ◽  
Right Atrial ◽  
Conduction Delay ◽  
Atrial Wall ◽  
Linear Probe ◽  
The Right ◽  
Ablation Line

Objective Cryoablation is commonly used at present in the surgical treatment of atrial fibrillation (AF). However, there have been few studies examining the efficacy of the commonly used ablation devices. This report compares the efficacy of two cryoprobes in creating transmural endocardial lesions on the beating heart in a porcine model for chronic AF. Methods In six Hanford miniature swine, the right atrial appendage and the inferior vena cava were isolated using a bipolar radiofrequency clamp to create areas of known conduction block. A connecting ablation line was performed endocardially via a purse string with the novel malleable 10-cm Cryo1 probe for 2 minutes at −40°C. Additional ablation lines were created with the Cryo1 and the 3.5-cm 3011 Maze Linear probe on the right and the left atrial wall. Epicardial activation mapping was performed before and immediately after ablation as well as 14 days postoperatively. Histologic examination was performed 14 days postoperatively. Results Transmural lesions were confirmed in 83/84 cross-sections (99%) for the Cryo1 probe and in 40/41 cross-sections (98%) for the 3011 Maze Linear probe. There was no difference between the devices in lesion width (mean ± SD, Cryo1, 10.7 ± 3.5 mm; 3011, 10.0 ± 3.9mm; P = 0.31), lesion depth (Cryo1, 4.5 ± 1.7 mm; 3011, 4.6 ± 1.5 mm; P = 0.74), or atrial wall thickness (Cryo1, 4.5 ± 1.8 mm; 3011, 4.7 ± 1.7 mm; P = 0.74). There was a conduction delay across the right atrial ablation line (20 ± 2 milliseconds vs 51 ± 8 milliseconds, P < 0.001) that remained unchanged at 14 days (51 ± 8 milliseconds vs 52 ± 10 milliseconds, P = 0.88). Conclusions The Cryo1 probe created transmural lesions on the beating heart, resulting insustained conduction delay. Both probes had a similar performance in lesion geometry in this chronic animal model.

Single-Patch Fold-Back Technique for Augmentation of the Superior Vena Cava in Sinus Venosus Atrial Septal Defect Associated with Partial Anomalous Pulmonary Venous Return

2015 ◽  
Vol 17 (6) ◽  
pp. 282
Author(s):  
Suguru Ohira ◽  
Kiyoshi Doi ◽  
Takeshi Nakamura ◽  
Hitoshi Yaku
Keyword(s):  
Atrial Septal Defect ◽  
Superior Vena Cava ◽  
Septal Defect ◽  
Venous Return ◽  
Superior Vena ◽  
Pulmonary Veins ◽  
Vena Cava ◽  
Sinus Venosus ◽  
Right Atrial ◽  
Anomalous Pulmonary Venous Return

Sinus venosus atrial septal defect (ASD) is usually associated with partial anomalous pulmonary venous return (PAPVR) of the right pulmonary veins to the superior vena cava (SVC), or to the SVC-right atrial junction. Standard procedure for repair of this defect is a patch roofing of the sinus venosus ASD and rerouting of pulmonary veins. However, the presence of SVC stenosis is a complication of this technique, and SVC augmentation is necessary in some cases. We present a simple technique for concomitant closure of sinus venosus ASD associated with PAPVR and augmentation of the SVC with a single autologous pericardial patch.

scholarly journals Use of ultrasound-measured internal jugular vein collapsibility index to determine static intracardiac pressures in patients with presumed pulmonary hypertension

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Raj Parikh ◽  
Matthew Spring ◽  
Janice Weinberg ◽  
Christine C. Reardon ◽  
Harrison W. Farber
Keyword(s):  
Pulmonary Hypertension ◽  
Internal Jugular Vein ◽  
Jugular Vein ◽  
Vena Cava ◽  
Right Atrial ◽  
Volume Status ◽  
Manual Compression ◽  
Respiratory Variation ◽  
Fluid Status ◽  
Collapsibility Index

Abstract Background Bedside ultrasound helps to estimate volume status in critically ill patients and has traditionally relied on diameter, respiratory variation, and collapsibility of the inferior vena cava (IVC) to reflect fluid status. We evaluated collapsibility of the internal jugular vein (IJ) with ultrasound and correlated it with concomitant right heart catheterization (RHC) measurements in patients with presumed pulmonary hypertension. Methods and results We studied 71 patients undergoing RHC for evaluation of pulmonary hypertension. Using two-dimensional ultrasound (Sonosite, Washington, USA), we measured the diameter of the IJ at rest, during respiratory variation, and during manual compression. Collapsibility index during respiration (respiratory CI) and during manual compression (compression CI) was calculated. We correlated mean right atrial pressure (mRAP) and pulmonary artery occlusion pressure (PAOP) defined by RHC measurements with respiratory and compression CI. A secondary goal was examining correlations between CI calculations and B-type natriuretic peptide (BNP) levels. Baseline characteristics demonstrated female predominance (n = 51; 71.8%), mean age 59.5 years, and BMI 27.3. There were significant correlations between decrease in compression CI and increase in both mRAP (Spearman: − 0.43; p value = 0.0002) and PAOP (Spearman: − 0.35; p value = 0.0027). In contrast, there was no significant correlation between respiratory CI and either mRAP (Spearman: − 0.14; p value = 0.35) or PAOP (Spearman:− 0.12; p value = 0.31). We also observed significant negative correlation between compression CI and BNP (Spearman: − 0.31; p value = 0.01) but not between respiratory CI and BNP (Spearman: − 0.12; p value = 0.35). Conclusion Increasing use of ultrasound has led to innovative techniques for estimating volume status. While prior ultrasound studies have used clinical parameters to estimate fluid status, our study used RHC measurements and demonstrated that compression CI potentially reflects directly measured mRAP and PAOP.

scholarly journals Obstruction of the inferior vena cava following bicaval orthotopic heart transplantation: a case series

2021 ◽  
Vol 5 (2) ◽  
Author(s):  
Anas Abudan ◽  
Brent Kidd ◽  
Peter Hild ◽  
Bhanu Gupta
Keyword(s):  
Inferior Vena Cava ◽  
Heart Transplantation ◽  
Inferior Vena ◽  
Rare Complication ◽  
Vena Cava ◽  
Case Series ◽  
Transoesophageal Echocardiography ◽  
Right Atrial ◽  
Orthotopic Heart Transplantation ◽  
Eustachian Valve

Abstract Background Inferior vena cava (IVC) obstruction is a rare complication of orthotopic heart transplantation (OHT) and is unique to bicaval surgical technique. The clinical significance, diagnosis, complications, and management of post-operative IVC anastomotic obstruction have not been adequately described. Case summary Two patients with end-stage heart failure presented for bicaval OHT. Post-operative course was complicated with shock refractory to fluid resuscitation and inotropic/vasopressor support. Obstruction at the IVC-right atrial (RA) anastomosis was diagnosed on transoesophageal echocardiography (TOE), prompting emergent reoperation. In both cases, a large donor Eustachian valve was found to be restricting flow across the IVC-RA anastomosis. Resection of the valve resulted in relief of obstruction across the anastomosis and subsequent improvement in haemodynamics and clinical outcome. Discussion Presumably rare, we present two cases of IVC obstruction post-bicaval OHT. Inferior vena cava obstruction is an under-recognized cause of refractory hypotension and shock in the post-operative setting. Prompt recognition using TOE is crucial for immediate surgical correction and prevention of multi-organ failure. Obstruction can be caused by a thickened Eustachian valve caught in the suture line at the IVC anastomosis, which would require surgical resection.

scholarly journals Isolated Marked Inferior Vena Cava Dilatation: Unusual Presentation or Underrecognized Common Phenomenon?

2018 ◽  
Vol 2018 ◽  
pp. 1-3 ◽  
Author(s):  
Sneha R. Gadi ◽  
Benjamin K. Ruth ◽  
Alan Johnson ◽  
Sula Mazimba ◽  
Younghoon Kwon
Keyword(s):  
Inferior Vena Cava ◽  
Inferior Vena ◽  
Vena Cava ◽  
Unusual Presentation ◽  
Atrial Pressure ◽  
Right Atrial ◽  
Right Atrial Pressure ◽  
Common Phenomenon ◽  
Right Heart

Inferior vena cava (IVC) diameter and respirophasic variation are commonly used echocardiographic indices to estimate right atrial pressure. While dilatation of the IVC and reduced collapsibility have traditionally been associated with elevated right heart filling pressures, the significance of isolated IVC dilatation in the absence of raised filling pressures remains poorly understood. We present a case of an asymptomatic 28-year-old male incidentally found to have IVC dilatation, reduced inspiratory collapse, and normal right heart pressures.

Increased cardiac output following occlusion of the descending thoracic aorta in dogs

1982 ◽  
Vol 243 (1) ◽  
pp. R152-R158 ◽  
Author(s):  
J. K. Stene ◽  
B. Burns ◽  
S. Permutt ◽  
P. Caldini ◽  
M. Shanoff
Keyword(s):  
Cardiac Output ◽  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Thoracic Aorta ◽  
Vascular System ◽  
Superior Vena ◽  
Vena Cava ◽  
Right Atrial ◽  
Mean Systemic Pressure ◽  
Extracorporeal Bypass

Occlusion of the thoracic aorta (AO) in dogs with a constant volume right ventricular extracorporeal bypass increased cardiac output (Q) by 43% and mean arterial pressure by 46%, while mean systemic pressure (MSP) was unchanged. We compared AO with occlusion of the brachiocephalic and left subclavian arteries (BSO) which decreased cardiac output by 5%, increased mean arterial pressure by 32%, and increased MSP by 11%. We feel these results confirm that AO elevates preload by transferring blood volume from the splanchnic veins to the vascular system drained by the superior vena cava. If the heart is competent to keep right arterial pressure at or near zero, this increase in preload will elevate Q above control levels. Comparing our data with results of other authors who have not controlled right atrial pressure, emphasizes the importance of a competent right ventricle in allowing venous return to determine Q.

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