A case of severe bleeding and deep inferior epigastric pseudoaneurysm after peritoneal dialysis catheter removal.

We present an unusual but severe complication of peritoneal dialysis (PD) catheter removal resulting in significant haemorrhage and hospitalisation. A patient presented for PD catheter removal under local anaesthesia in the interventional radiology suite and was noted to have a heavily calcified deep Dacron cuff. This cuff was intimately associated with a deep inferior epigastric perforating (DIEP) vessel. Removal of the catheter resulted in shearing of DIEP vessel and pseudoaneurysm formation. Despite attempted surgical management with ligation haemorrhage continued, requiring urgent angiographic embolisation to stop the bleeding. Intimate relationship between DIEP vessel and Dacron cuff due to calcification was the cause of this complication. This case report represents a rare but important complication associated with PD catheter removal, highlighting that when calcification is seen at the deep cuff, caution should be exercised and there should be access to angiography suite in case of complication.

Physiological Bases for the Superiority of Apolipoprotein B Over Low-Density Lipoprotein Cholesterol and Non-High-Density Lipoprotein Cholesterol as a Marker of Cardiovascular Risk.

In 2019, the European Society of Cardiology/European Atherosclerosis Society stated that apolipoprotein B (apoB) was a more accurate marker of cardiovascular risk than low-density lipoprotein cholesterol (LDL-C) and non-high-density lipoprotein cholesterol. Since then, the evidence has continued to mount in favor of apoB. This review explicates the physiological mechanisms responsible for the superiority of apoB as a marker of the cardiovascular risk attributable to the atherogenic apoB lipoprotein particles chylomicron remnants, very low-density lipoprotein, and low-density lipoprotein particles. First, the nature and relative numbers of these different apoB particles will be outlined. This will make clear why low-density lipoprotein particles are almost always the major determinants of cardiovascular risk and why the concentrations of triglycerides and LDL-C may obscure this relation. Next, the mechanisms that govern the number of very low-density lipoprotein and low-density lipoprotein particles will be outlined because, except for dysbetalipoproteinemia, the total number of apoB particles determines cardiovascular risk, Then, the mechanisms that govern the cholesterol mass within very low-density lipoprotein and low-density lipoprotein particles will be reviewed because these are responsible for the discordance between the mass of cholesterol within apoB particles, measured either as LDL-C or non-high-density lipoprotein cholesterol, and the number of apoB particles measured as apoB, which creates the superior predictive power of apoB over LDL-C and non-high-density lipoprotein cholesterol. Finally, the major apoB dyslipoproteinemias will be briefly outlined. Our objective is to provide a physiological framework for health care givers to understand why apoB is a more accurate marker of cardiovascular risk than LDL-C or non-high-density lipoprotein cholesterol.

Quality Improvement in Canadian Nephrology: Key Considerations in Ensuring Thoughtful Ethical Oversight.

PURPOSE OF REVIEW: Quality improvement (QI) work is a cornerstone of health care, and a growing area within nephrology. With such growth comes the need to ensure that QI activities are implemented in an ethically responsible manner. The existing institutional research board (IRB) framework has largely focused on reviewing the ethical suitability of traditional research projects, and it can be challenging to know if QI initiatives require formal ethics oversight. Several tools have been developed to assist in distinguishing between the two, such as the "A pRoject Ethics Community Consensus Initiative" tool. Our objective was to demonstrate how QI is distinct from research, to outline how QI-focused IRB process is used across Canada, and to develop a practical aid for clinicians embarking on QI-related projects. SOURCES OF INFORMATION: Publicly available institutional Web sites from academic and select nonacademic sites across Canada. METHODS: Institutional Web sites across all academic centers within Canada were examined to determine local QI-specific ethics review processes. We have provided examples of QI processes from select community sites. We have developed a tool to assist clinicians navigate the ethical challenges of QI projects and to determine whether their project may require ethics approval. KEY FINDINGS: This overview of the considerations of the research ethics approval process helps clinicians to determine whether IRB approval is required for QI studies. Examples of the current ethical processes employed in both academic and community institutions across Canada demonstrate the variability between centers. We have included examples of fictional nephrology-oriented QI initiatives to illustrate when ethics approval may be considered, along with a flowchart. This summary highlights the opportunity for QI-specific IRB review processes to be standardized across Canada, along with the need for creation of a separate stream with dedicated expertise for QI project review. LIMITATIONS: We did not do a formal environmental scan of the QI IRB review process in all hospital institutions across Canada.

JUSTIFICATION: Les travaux visant l'amélioration de la qualité (AQ) sont une des pierres angulaires des soins de santé. L'AQ est un secteur en croissance en néphrologie et avec une telle croissance vient la nécessité de s'assurer que les activités d'AQ sont mises en œuvre de manière éthique et responsable. Le cadre actuel des comités d'éthique de la recherche (CER) s'est essentiellement concentré sur l'examen de la pertinence éthique des projets de recherche traditionnels, et il peut être difficile de savoir si les initiatives d'AQ nécessitent une surveillance formelle de l'éthique. Plusieurs outils ont été mis au point pour faciliter la distinction entre les deux, notamment l'ARECCI. Notre objectif était de démontrer en quoi l'AQ se distingue de la recherche, d'indiquer dans quelle mesure les processus des CER sont axés sur l'AQ à travers le Canada et de développer une aide pratique pour les cliniciens qui se lancent dans des projets relatifs à l'AQ. SOURCES: Des sites institutionnels accessibles au public provenant de sites universitaires et de certains sites non universitaires à travers le Canada. MÉTHODOLOGIE: Les sites Web institutionnels de tous les centers universitaires du Canada ont été examinés afin de déterminer les processus locaux d'examen de l'éthique propres à l'AQ. Nous avons fourni des exemples de processus d'AQ provenant de sites communautaires sélectionnés. Nous avons mis au point un outil pour aider les cliniciens à relever les défis éthiques des projets d'AQ et à déterminer si leur projet pourrait nécessiter une approbation éthique. PRINCIPAUX RÉSULTATS: Cet aperçu des éléments à considérer dans le processus d'approbation de l'éthique de la recherche aide les cliniciens à déterminer si l'approbation du CER est requise pour les études d'AQ. Les exemples des processus d'examen de l'éthique qui sont actuellement employés dans les établissements universitaires et communautaires du Canada démontrent la variabilité entre les centers. Nous avons inclus un diagramme de flux et des exemples d'initiatives fictives d'AQ axées sur la néphrologie pour illustrer les cas où l'approbation de l'éthique peut être envisagée. Ce résumé met en évidence la possibilité d'uniformiser les processus d'examen des CER propres à l'AQ dans l'ensemble du Canada, ainsi que la nécessité de créer un volet distinct doté d'une expertise dédiée à l'examen des projets d'AQ. LIMITES: Nous n'avons pas procédé à une analyze environnementale officielle du processus d'examen de l'AQ par les CER de tous les établissements hospitaliers du Canada.

Key Questions About Familial Hypercholesterolemia: JACC Review Topic of the Week.

Familial hypercholesterolemia (FH) is characterized as a monogenic, autosomal dominant disorder, producing severe hypercholesterolemia within families due to causal variants within genes regulating the low-density lipoprotein receptor pathway. Demonstration of a causal variant is widely accepted as evidence of substantially higher cardiovascular risk. However, recent large-scale population studies challenge this characterization of FH, which appears to account for only a minor portion of those with severe hypercholesterolemia. Moreover, a substantial portion of FH variant positive patients do not have marked hypercholesterolemia. These discordances raise doubt as to how FH should be defined and how the concentration of low-density lipoprotein in plasma is regulated in individuals with and without FH. Moreover, review of the evidence suggests the impact of an FH causal variant on cardiovascular risk may be less than previously accepted and that all patients with severe hypercholesterolemia should be prioritized for therapy and family screening.

An Environmental Scan and Evaluation of Quality Indicators Across Canadian Kidney Transplant Centers.

BACKGROUND: Kidney transplantation is the optimal treatment for an individual requiring kidney replacement therapy, resulting in improved survival and quality of life while costing the health care system less than maintenance dialysis. Achieving and maintaining a kidney transplant requires extensive coordination of several different health care services. To improve the quality of kidney transplant care, quality metrics or indicators that encompass all aspects of the individual's journey to transplant should be measured in a standardized fashion. OBJECTIVE: To identify, categorize, and evaluate strengths and weaknesses of kidney transplant quality indicators currently being used across Canada. DESIGN: An environmental scan of quality indicators being used by kidney organizations and programs. SETTING: A 16-member volunteer pan-Canadian panel with expertise in nephrology, transplant, and quality improvement. SAMPLE: Transplant programs, as well as provincial transplant and kidney agencies across Canada. METHODS: Indicators were first categorized based on the period of transplant care and then using the Institute of Medicine and Donabedian frameworks. A 4-member subcommittee rated each indicator using a modified version of the Delphi consensus technique based on the American College of Physician/Agency for Healthcare Research and Quality criteria. Consensus ratings were subsequently shared with the entire 16-member panel for additional comments. RESULTS: We identified 46 measures related to transplant care across 7 Canadian provinces (9 referral and evaluation, 9 waitlist activity and outcomes, 6 hospitalization for transplant surgery, 12 posttransplant care, 6 organ utilization, 4 living donor). We rated 24 indicators (52%) as necessary to distinguish high-quality from low-quality care, most of which measured effective (n = 10) or efficient (n = 6) care. Only 7 (15%) of 46 indicators evaluated person-centered or equitable care. Fourteen common indicators were measured by 5 of 7 provinces, 10 of which were deemed "necessary," measuring safe (n = 2), effective (n = 5), efficient (n = 2), and equitable (n = 1) care. LIMITATIONS: The panel lacked patient and allied health representation. CONCLUSIONS: There are a large number of kidney transplant quality indicators currently being used in Canada, some of which are common across provinces and focus primarily on measuring effective care. Person-centered and equitable care indicators were lacking, and only half of these indicators were deemed "necessary" for quality improvement. Our results should complement ongoing work to achieve national consensus on the standardization of quality indicators in kidney transplantation.

CONTEXTE: La transplantation rénale constitue le traitement optimal pour une personne nécessitant une thérapie de remplacement rénal. La greffe améliore la survie et la qualité de vie du patient, tout en s'avérant moins coûteuse pour le système de santé que la dialyse d'entretien. La réussite et le maintien d'une transplantation rénale requièrent la parfaite coordination de plusieurs services de santé différents. L'amélioration des soins entourant la greffe passe donc par la mesure normalisée des indicateurs de qualité qui englobent tous les aspects du cheminement du patient vers la transplantation. OBJECTIFS: Identifier, classer et évaluer les forces et faiblesses des indicateurs actuellement utilisés au Canada pour mesurer la qualité des soins entourant la transplantation rénale. TYPE D'ÉTUDE: Analyse contextuelle des indicateurs de la qualité utilisés par les organismes et programmes de néphrologie. CADRE: Un comité bénévole pancanadien composé de 16 personnes détenant une expertise en néphrologie, en transplantation et en amélioration de la qualité. ÉCHANTILLON: Les programmes de transplantation et les organismes provinciaux de transplantation et de néphrologie partout au Canada. MÉTHODOLOGIE: Les indicateurs ont d'abord été catégorisés selon le moment des soins, puis avec les modèles de l'Institute of Medicine et de Donabedian. Un sous-comité de quatre personnes a évalué les indicateurs à l'aide d'une version modifiée de la méthode Delphi basée sur les critères de l'American College of Physicians/Agency for Healthcare Research and Quality. Les évaluations consensuelles ont ensuite été partagées avec les 16 membres du comité afin de recueillir d'autres commentaires. RÉSULTATS: Nous avons recensé 46 mesures liées aux soins de transplantation dans sept provinces canadiennes (9 aiguillages et évaluations, 9 activités et résultats liés à la liste d'attente, 6 hospitalisations en vue d'une greffe, 12 soins post-transplantation, 6 utilisations d'organes et 4 donneurs vivants). Nous avons évalué 24 indicateurs (52 %) comme étant nécessaires pour départager les soins de haute qualité des soins de mauvaise qualité, la plupart mesurant l'efficacité (n = 10) ou l'efficience (n = 6). Seuls 7 indicateurs sur 46 (15 %) évaluaient des soins équitables ou axés sur la personne. Quatorze indicateurs communs étaient mesurés par cinq des sept provinces. Parmi eux, dix mesurant des soins sûrs (n = 2), efficaces (n = 5), efficients (n = 2) et équitables (n = 1) ont été jugés « nécessaires ¼. LIMITES: Le comité manquait de représentation parmi les patients et les professionnels paramédicaux. CONCLUSION: Un grand nombre d'indicateurs de la qualité de la transplantation rénale sont utilisés au Canada, certains sont communs à plusieurs provinces et mettent principalement l'accent sur l'efficacité des soins. Mais seulement la moitié de ceux-ci sont jugés « nécessaires ¼ pour améliorer la qualité. De plus, des indicateurs quant aux soins équitables et axés sur la personne manquaient. Nos résultats devraient compléter les travaux en cours visant l'obtention d'un consensus national sur la normalisation des indicateurs de qualité en transplantation rénale.

Apolipoprotein B: the Rosetta Stone of lipidology.

PURPOSE OF REVIEW: This review summarizes the evidence that apolipoprotein B (apoB) integrates the conventional lipid markers - total cholesterol, triglycerides, LDL-cholesterol, and non-HDL-cholesterol - into a single index that accurately and simply quantitates the atherogenic risk due to the apoB lipoprotein particles. RECENT FINDINGS: Marked hypertriglyceridemia remains the essential signal for hyperchylomicronemia and potential pancreatitis. However, with the exception of Lp(a) and the abnormal cholesterol-enriched remnant particles that are the hallmark of type III hyperlipoproteinemia, recent evidence from discordance analyses and Mendelian randomization indicate that apoB integrates the risk due to the atherogenic lipoprotein particles because all LDL particles are, within the limits of our ability to measure any differences, equally atherogenic and all, except the largest VLDL particles are, within the limits of our ability to measure any differences, equally atherogenic. SUMMARY: Measuring apoB as well as the conventional lipids is essential for accurate diagnosis. For almost all follow-up, however, apoB is all that need be measured. ApoB is the Rosetta Stone of lipidology because dyslipoproteinemia cannot be understood unless apoB is measured.

Prescribing high-quality peritoneal dialysis: Moving beyond urea clearance.

Urea removal in peritoneal dialysis (PD) has been a primary measure of dialysis adequacy, but its utility remains limited due to its poor correlation with the clearance of other important uraemic retention solutes and the low certainty of evidence relating peritoneal urea clearance and survival of individuals doing PD. Indeed, clearances of other uraemic solutes, electrolyte imbalances, hypoalbuminaemia and nutritional status, may provide a more holistic measure of dialysis adequacy when evaluating individuals on PD in addition to focusing on person-centred outcomes. Here, we review the history of the urea and creatinine-centric approach to dialysis adequacy and explore the potential importance of other uraemic retention solutes, electrolyte disturbances, phosphorus control, peritoneal protein losses and hypoalbuminaemia, as well as nutritional management to promote a broader multidimensional concept of clearance for PD.

Apolipoprotein B Particles and Cardiovascular Disease: A Narrative Review.

Importance: The conventional model of atherosclerosis presumes that the mass of cholesterol within very low-density lipoprotein particles, low-density lipoprotein particles, chylomicron, and lipoprotein (a) particles in plasma is the principal determinant of the mass of cholesterol that will be deposited within the arterial wall and will drive atherogenesis. However, each of these particles contains one molecule of apolipoprotein B (apoB) and there is now substantial evidence that apoB more accurately measures the atherogenic risk owing to the apoB lipoproteins than does low-density lipoprotein cholesterol or non-high-density lipoprotein cholesterol. Observations: Cholesterol can only enter the arterial wall within apoB particles. However, the mass of cholesterol per apoB particle is variable. Therefore, the mass of cholesterol that will be deposited within the arterial wall is determined by the number of apoB particles that are trapped within the arterial wall. The number of apoB particles that enter the arterial wall is determined primarily by the number of apoB particles within the arterial lumen. However, once within the arterial wall, smaller cholesterol-depleted apoB particles have a greater tendency to be trapped than larger cholesterol-enriched apoB particles because they bind more avidly to the glycosaminoglycans within the subintimal space of the arterial wall. Thus, a cholesterol-enriched particle would deposit more cholesterol than a cholesterol-depleted apoB particle whereas more, smaller apoB particles that enter the arterial wall will be trapped than larger apoB particles. The net result is, with the exceptions of the abnormal chylomicron remnants in type III hyperlipoproteinemia and lipoprotein (a), all apoB particles are equally atherogenic. Conclusions and Relevance: Apolipoprotein B unifies, amplifies, and simplifies the information from the conventional lipid markers as to the atherogenic risk attributable to the apoB lipoproteins.

A Peritoneal Dialysis Access Quality Improvement Initiative: A Single-Center Experience.

Background:Little evidence exists regarding optimal peritoneal dialysis (PD) access insertion pathways, benchmarking for patency targets, and definitions of access dysfunction.Methods:This quality improvement (QI) project evaluated patients with PD catheters inserted at a single center in Toronto, Canada, following: establishment of PD catheter insertion protocols, a PD access coordinator, PD access operator training, and outcomes reporting. We define primary vs secondary PD catheter dysfunction by presentation before/after initial home PD treatment. We report catheter dysfunction rates, interventions restoring PD catheter patency (interventional radiology [IR] vs advanced laparoscopic [AL]) (embedded vs non-embedded) between 2012 and 2017.Results:A total of 297 first PD catheters were inserted between January 2012 and December 2017. Interventional radiology PD catheters (n = 94) were placed in older patients with greater comorbidities and less prior abdominal surgery than AL-placed catheters. Indications for IR insertion included need for urgent dialysis given resource availability (36.2% [n = 34]) and prohibitive surgical risk (26.6% [n = 25]). Interventional radiology-inserted catheters had overall (primary and secondary) dysfunction rates of 17%. Non-embedded AL catheters had 16.1% overall dysfunction. Embedded AL-inserted PD catheters had a 24.6% overall dysfunction rate. Among all dysfunctional catheters, IR manipulation was successful in 31% (n = 11), and surgical revision was necessary in all unsuccessful cases with either lysis of adhesions or omentopexy to establish patency.Conclusion:Our PD catheter QI initiative involved tracking, outcome reporting, defining PD catheter dysfunction and PD access insertion pathway development, yielding important insights into opportunities for program improvement. Multicenter research initiatives are needed to further improve PD access dysfunction definitions and to establish the best benchmarks for these metrics.

CKD and Sedentary Time: Results From the Canadian Health Measures Survey.

RATIONALE & OBJECTIVE: Sedentary behavior and low physical activity are associated with incident diabetes, cardiovascular disease, and early mortality. Previous studies have examined associations between chronic kidney disease (CKD) and physical activity, but little is known about the role of sedentary time. STUDY DESIGN: Cross-sectional national survey. SETTING & PARTICIPANTS: A nationally representative sample of adults (n=8,444) participating in the Canadian Health Measures Survey's (CHMS) activity monitoring component (2007-2013). PREDICTOR: Estimated glomerular filtration rate (eGFR). OUTCOMES: Sedentary time (total sedentary minutes/total wear time) measured using triaxial accelerometry. ANALYTICAL APPROACH: Multivariable ordinal logistic regression for quartiles of sedentary time and linear regression for sedentary time measured on a continuous scale were performed in the entire study population and in the subgroup with CKD. RESULTS: Mean proportion of sedentary time ranged from 58% (least sedentary quartile: Q1) to 81% (most sedentary quartile: Q4). Lower eGFR, older age, lower serum albumin level, higher blood pressure, cardiovascular disease, diabetes, and higher body mass index were independently associated with a higher proportion of sedentary time. Patients with eGFRs < 45mL/min/1.73m2 had more than 4-fold higher likelihood of being sedentary (OR, 4.2; 95% CI, 2.5-7.3). Within the CKD subgroup, greater sedentary time was associated with diabetes (OR, 2.68; 95% CI, 1.56-4.59) and arthritis (OR, 2.32; 95% CI, 1.43-3.77) in adjusted analysis. LIMITATIONS: Cross-sectional design precluded evaluation of longitudinal outcomes and establishment of the causal nature of observed associations. Small sample of individuals with advanced CKD. CONCLUSIONS: In this cross-sectional survey, reduced eGFR was strongly and independently associated with greater sedentary time. This risk was further heightened by the presence of diabetes and arthritis. Studies to determine causes for sedentary behavior and assess the feasibility and value of interventions to reduce sedentary time in CKD are needed.

The utility of cardiac biomarkers and echocardiography for the early detection of bevacizumab- and sunitinib-mediated cardiotoxicity.

The recent introduction of novel anticancer therapies, including bevacizumab (BVZ) and sunitinib (SNT), is associated with an increased risk of cardiotoxicity. However, early identification of left ventricular (LV) systolic dysfunction may facilitate dose modification and avoid the development of advanced heart failure. Using a murine model of BVZ- and SNT-mediated cardiotoxicity, we investigated whether cardiac biomarkers and/or tissue velocity imaging (TVI) using echocardiography can detect early changes in cardiac function, before a decrease in LV ejection fraction is identified. A total of 75 wild-type C57Bl/6 male mice were treated with either 0.9% saline, BVZ, or SNT. Serial monitoring of blood pressure, high-sensitivity troponin I, and echocardiographic indexes were performed over a 14-day study period, after which the mice were euthanized for histological and biochemical analyses. Mice treated with either BVZ or SNT developed systemic hypertension as early as day 7, which increased by day 14. Cardiac biomarkers, specifically high-sensitivity troponin I, were not predictive of early LV systolic dysfunction. Although conventional LV ejection fraction values decreased at day 13 in mice treated with either BVZ or SNT, TVI confirmed early LV systolic dysfunction at day 8. Histological and biochemical analysis demonstrated loss of cellular integrity, increased oxidative stress, and increased cardiac apoptosis in mice treated with BVZ or SNT therapy at day 14. In a murine model of BVZ- or SNT-mediated cardiomyopathy, noninvasive assessment by TVI detected early LV systolic dysfunction before alterations in conventional echocardiographic indexes.

Early diagnosis and management of myocardial rupture.

Left ventricular free wall rupture is a catastrophic mechanical complication of myocardial infarction. We present an 82-year-old woman with an anterolateral ST segment elevation myocardial infarction treated with thrombolysis. Because of unexplained hypotension, echocardiography was performed and contrast (Definity; Lantheus Medical Imaging) was used to improve visualization. Findings included a small- to moderate-sized circumferential pericardial effusion without frank tamponade, however, there was significant intramyocardial tracking of the contrast into the epicardial space, localized to the mid to apical portion of the anterior septum, consistent with rupture or disruption of the wall segment. The patient was promptly taken to the operating room where fresh blood and clots were evacuated from the pericardial space with immediate hemodynamic improvement. The patient underwent successful surgical repair.

Right ventricular free wall dyskinesis in the setting of left ventricular non compaction: a case report.

BACKGROUND: Left ventricular non compaction is a relatively rare congenital disorder characterized by prominent trabeculations and intertrabecular recesses with the potential for thromboembolism, arrhythmias, and sudden cardiac death as adverse effects. Echocardiography has traditionally been employed as the primary mode of imaging; however, with the advent of cardiac magnetic resonance as a more precise imaging technique, the disorder known as left ventricle non compaction is becoming more broadly defined with increasing recognition of right ventricle (RV) involvement. CASE PRESENTATION: This report describes a 52-year-old Caucasian female with new onset atrial fibrillation with an unusual finding of left ventricular non compaction and right ventricular dysfunction on transthoracic echocardiogram with preserved left ventricular ejection fraction. Cardiac magnetic resonance imaging demonstrated a disproportionately affected right ventricle, with apical free wall dyskinesis. CONCLUSIONS: This case illustrates the unique occurrence of left ventricular non compaction with preserved ejection fraction alongside RV free wall dyskinesis and RV systolic dysfunction. The significance of this is yet unknown given the paucity of existing literature. This report serves to highlight the vast heterogeneity within left ventricular non compaction as we are better able to delineate this disorder using increasingly sophisticated imaging techniques.

Longterm effects of cardiac mediastinal nerve cryoablation on neural inducibility of atrial fibrillation in canines.

In canines, excessive activation of select mediastinal nerve inputs to the intrinsic cardiac nervous system induces atrial fibrillation (AF). Since ablation of neural elements is proposed as an adjunct to circumferential pulmonary vein ablation for AF, we investigated the short and long-term effects of mediastinal nerve ablation on AF inducibility. Under general anesthesia, in 11 dogs several mediastinal nerve sites were identified on the superior vena cava that, when stimulated electrically during the atrial refractory period, reproducibly initiated AF. Cryoablation of one nerve site was then performed and inducibility retested early (1-2 months post Cryo; n=7) or late (4 months post Cryo; n=4). Four additional dogs that underwent a sham procedure were retested 1 to 2 months post-surgery. Stimulation induced AF at 91% of nerve sites tested in control versus 21% nerve sites early and 54% late post-ablation (both P<0.05). Fewer stimuli were required to induce AF in controls versus the Early Cryo group; this capacity returned to normal values in the Late Cryo group. AF episodes were longer in control versus the Early or Late Cryo groups. Heart rate responses to vagal or stellate ganglion stimulation, as well as to local nicotine infusion into the right coronary artery, were similar in all groups. In conclusion, focal damage to intrinsic cardiac neuronal inputs causes short-term stunning of neuronal inducibility of AF without major loss of overall adrenergic or cholinergic efferent neuronal control. That recovery of AF inducibility occurs rapidly post-surgery indicates the plasticity of intrathoracic neuronal elements to focal injury.