Attenuated heart rate recovery is associated with higher arrhythmia recurrence and mortality following atrial fibrillation ablation.

AIMS: Heart rate recovery (HRR), the decrease in heart rate occurring immediately after exercise, is caused by the increase in vagal activity and sympathetic withdrawal occurring after exercise and is a powerful predictor of cardiovascular events and mortality. The extent to which it impacts outcomes of atrial fibrillation (AF) ablation has not previously been studied. The aim of this study is to investigate the association between attenuated HRR and outcomes following AF ablation. METHODS AND RESULTS: We studied 475 patients who underwent EST within 12 months of AF ablation. Patients were categorized into normal (>12 b.p.m.) and attenuated (≤12 b.p.m.) HRR groups. Our main outcomes of interest included arrhythmia recurrence and all-cause mortality. During a mean follow-up of 33 months, 43% of our study population experienced arrhythmia recurrence, 74% of those with an attenuated HRR, and 30% of those with a normal HRR (P < 0.0001). Death occurred in 9% of patients in the attenuated HRR group compared to 4% in the normal HRR cohort (P = 0.001). On multivariable models adjusting for cardiorespiratory fitness (CRF), medication use, left atrial size, ejection fraction, and renal function, attenuated HRR was predictive of increased arrhythmia recurrence (hazard ratio 2.54, 95% confidence interval 1.86-3.47, P < 0.0001). CONCLUSION: Heart rate recovery provides additional valuable prognostic information beyond CRF. An impaired HRR is associated with significantly higher rates of arrhythmia recurrence and death following AF ablation.

Holospinal epidural abscess of the spinal axis: two illustrative cases with review of treatment strategies and surgical techniques.

Despite the increasing prevalence of spinal infections, the subcategory of holospinal epidural abscesses (HEAs) is extremely infrequent and requires unique management. Panspinal imaging (preferably MRI), modern aggressive antibiotic therapy, and prompt surgical intervention remain the standard of care for all spinal axis infections including HEAs; however, the surgical decision making on timing and extent of the procedure still remain ill defined for HEAs. Decompression including skip laminectomies or laminoplasties is described, with varied clinical outcomes. In this review the authors present the illustrative cases of 2 patients with HEAs who were treated using skip laminectomies and epidural catheter irrigation techniques. The discussion highlights different management strategies including the role of conservative (nonsurgical) management in these lesions, especially with an already identified pathogen and the absence of mass effect on MRI or significant neurological defects. Among fewer than 25 case reports of HEA published in the past 25 years, the most important aspect in deciding a role for surgery is the neurological examination. Nearly 20% were treated successfully with medical therapy alone if neurologically intact. None of the reported cases had an associated cranial infection with HEA, because the dural adhesion around the foramen magnum prevented rostral spread of infection. Traditionally a posterior approach to the epidural space with irrigation is performed, unless an extensive focal ventral collection is causing cord compression. Surgical intervention for HEA should be an adjuvant treatment strategy for all acutely deteriorating patients, whereas aspiration of other infected sites like a psoas abscess can determine an infective pathogen, and appropriate antibiotic treatment may avoid surgical intervention in the neurologically intact patient.

Cardioneuroablation for the Treatment of Hypervagotonic Sinus Node Dysfunction.

Hypervagotonic sinus node dysfunction (SND) is a form of SND with sinus bradycardia caused by enhanced vagal tone. Indirect proof of hypervagotonia as the mechanism can be inferred from resolution of bradycardia following atropine infusion. In symptomatic patients, pacemaker implantation is recommended. We describe cardioneuroablation as a treatment for hypervagotonic SND.

Biomedical engineering strategies for peripheral nerve repair: surgical applications, state of the art, and future challenges.

Damage to the peripheral nervous system is surprisingly common and occurs primarily from trauma or a complication of surgery. Although recovery of nerve function occurs in many mild injuries, outcomes are often unsatisfactory following severe trauma. Nerve repair and regeneration presents unique clinical challenges and opportunities, and substantial contributions can be made through the informed application of biomedical engineering strategies. This article reviews the clinical presentations and classification of nerve injuries, in addition to the state of the art for surgical decision-making and repair strategies. This discussion presents specific challenges that must be addressed to realistically improve the treatment of nerve injuries and promote widespread recovery. In particular, nerve defects a few centimeters in length use a sensory nerve autograft as the standard technique; however, this approach is limited by the availability of donor nerve and comorbidity associated with additional surgery. Moreover, we currently have an inadequate ability to noninvasively assess the degree of nerve injury and to track axonal regeneration. As a result, wait-and-see surgical decisions can lead to undesirable and less successful "delayed" repair procedures. In this fight for time, degeneration of the distal nerve support structure and target progresses, ultimately blunting complete functional recovery. Thus, the most pressing challenges in peripheral nerve repair include the development of tissue-engineered nerve grafts that match or exceed the performance of autografts, the ability to noninvasively assess nerve damage and track axonal regeneration, and approaches to maintain the efficacy of the distal pathway and targets during the regenerative process. Biomedical engineering strategies can address these issues to substantially contribute at both the basic and applied levels, improving surgical management and functional recovery following severe peripheral nerve injury.

Operator learning curve and clinical outcomes of zero fluoroscopy catheter ablation of atrial fibrillation, supraventricular tachycardia, and ventricular arrhythmias.

PURPOSE: To investigate the learning curve for atrial fibrillation (AF), supraventricular tachycardia (SVT), and premature ventricular contraction (PVC) radiofrequency ablation (RFA) using zero fluoroscopy. METHODS: This is a retrospective, single-center study of 167 patients undergoing ablation between 2016 and 2019. Minimal fluoroscopy approach was initiated after the first 20 cases of PVI and SVT RFA. Procedures were divided consecutively into increments of 10 cases to determine operator learning curve. RESULTS: A total of 64 (38%) had SVT ablations, 26 (16%) had PVC ablations, and 77 (46%) had AF and underwent PVI. For SVT RFA, fluoroscopy time improved from 4.1 ± 3.5 min during the first 10 cases to 0.8 ± 1.2 min after 50 cases (p = 0.0001). Sixty-two out of 64 (97%) of cases were successful. In PVC RFA, fluoroscopy time was 7.7 ± 5.5 min for the first 5, 2.3 ± 3.4 min after 15, and 0 min after 20 cases (p = 0.0008). Twenty-four out of 26 (92%) of cases were acutely successful with recurrence in 2/26 (8%) of patients over 9 ± 9 months. In PVI, fluoroscopy time was 9.9 ± 3.3 min over the first 20 cases, 2.6 ± 2.3 min after 40 cases, and 0.1 min after 50 cases (p < 0.0001). PVI procedure time was 170 ± 34 min after 60 cases from 235 ± 41 min initially (p 0.001). Six out of 77 (8%) had AF recurrence at 12 months. CONCLUSIONS: Zero fluoroscopy ablation for AF, SVT, and PVC can be safely achieved without increasing procedure time. The steepest learning curve occurs over the first 20, 15, and 40 cases for SVT, PVC, and PVI ablation respectively.

Impact of Nonalcoholic Fatty Liver Disease on Arrhythmia Recurrence Following Atrial Fibrillation Ablation.

OBJECTIVES: This study sought to investigate the association between nonalcoholic fatty liver disease (NAFLD) and arrhythmia recurrence following atrial fibrillation ablation; and to examine the impact of NAFLD stage on outcomes. BACKGROUND: Metabolic derangements, including obesity and diabetes, are associated with incident and recurrent atrial fibrillation (AF), in addition to the development of NAFLD. METHODS: This was a retrospective study of 267 consecutive patients undergoing AF ablation, 89 of whom were diagnosed with NAFLD prior to ablation and matched in a 2:1 manner based on age, sex, body mass index, ejection fraction, and AF type with 178 patients without NAFLD. Patients were monitored for arrhythmia recurrence during a mean follow-up of 29 months. RESULTS: Recurrent arrhythmia was observed in 50 (56%) patients with NAFLD compared with 37 (21%) without NAFLD. Epicardial fat volume was measured on computed tomography and was significantly higher among those with NAFLD (248 ± 125 ml vs. 223 ± 97 ml; p = 0.01). On multivariable models adjusting for sleep apnea, body mass index, heart failure, AF type, and left atrial size, NAFLD was independently associated with increased rates of arrhythmia recurrence (hazard ratio: 3.010; 95% confidence interval: 1.980 to 4.680; p < 0.0001). CONCLUSIONS: NAFLD is associated with significantly increased arrhythmia recurrence rates following AF ablation. Identification and reversal, where possible, may result in improved arrhythmia-free survival.

Prevalence, Incidence, and Impact on Mortality of Conduction System Disease in Transthyretin Cardiac Amyloidosis.

Transthyretin cardiac amyloidosis (ATTR-CA) is an increasingly recognized infiltrative cardiomyopathy in which conduction system disease is common. The aim of our study was to define the incidence and prevalence of high-grade atrioventricular (AV) block requiring pacemaker implantation in our quaternary referral center. This was a single-center retrospective cohort study of 369 consecutive patients with ATTR-CA who underwent 12-lead electrocardiogram at the time of ATTR-CA diagnosis. During a mean follow-up of 28 months, serial ECGs and the electronic medical record were examined for the development of high-grade AV block and pacemaker implantation. Wild-type ATTR-CA (wtATTR-CA) was diagnosed in 261 patients and 108 had hereditary ATTR-CA (hATTR-CA). A total of 35 (9.5%) had high-grade AV block requiring pacemaker implantation at the time of diagnosis of ATTR-CA. The most common conduction abnormalities evident on the baseline ECG were a wide QRS complex, present in 51% with wtATTR-CA and 48% with hATTR-CA (p = 0.62), followed by first-degree AV block, which was present in 49% with wtATTR-CA and 43% with hATTR-CA (p = 0.31). During follow-up, high-grade AV block developed in 10% of those with hATTR-CA and 12% of patients with wtATTR-CA (p = 0.64). On multivariable models, high-grade AV block was not significantly associated with increased mortality. More advanced ATTR-CA stage and a history of obstructive coronary artery disease were associated with increased mortality on multivariable models. In conclusion, the incidence and prevalence of high-grade AV block is high in patients with ATTR-CA. Patients with ATTR-CA require close monitoring during follow-up for the development of conduction system disease.

Impact of Bariatric Surgery on Atrial Fibrillation Type.

BACKGROUND: Obesity is an independent risk factor for atrial fibrillation (AF) and is associated with a higher AF burden. Recently, weight loss has been found to be associated with a significant reversal in AF type. Bariatric surgery (BS) is associated with reductions in inflammation, left atrial and ventricular remodeling, sleep apnea, blood pressure, and improved glycemic control, all of which may reduce AF burden. In this study, we sought to determine the impact of BS on AF type. METHODS: We studied AF type before and after BS in 220 morbidly obese patients (body mass index, ≥40 kg/m2). All patients underwent extended outpatient cardiac rhythm monitoring within 12 months of BS and at least 1 year after BS. RESULTS: There was a significant reduction in body mass index following BS from 49.7±9 to 37.2±9 kg/m2. Weight loss was the greatest in the gastric bypass group with a mean percentage weight loss of 25% compared with 19% in patients who underwent sleeve gastrectomy and 16% following gastric banding (P<0.0001). Significant reductions in CRP (C-reactive protein), NT-proBNP (N-terminal pro-B-type natriuretic peptide), HbA1C (glycated hemoglobin), and systolic blood pressure were observed in all 3 groups. Reversal of AF type occurred in 71% of patients following gastric bypass, 56% of patients who underwent sleeve gastrectomy, and 50% of patients following gastric banding (P=0.004). On Cox proportional hazards analyses, percentage weight loss was significantly associated with AF reversal (P=0.0002). CONCLUSIONS: BS is associated with significant reductions in weight, inflammatory markers, blood pressure, and AF type, and the beneficial effects appear to be the greatest in those undergoing gastric bypass surgery. This study further exemplifies the importance of weight loss and risk factor modification in AF management.

Strategies for Catheter Ablation of Left Ventricular Papillary Muscle Arrhythmias: An Institutional Experience.

OBJECTIVES: This study sought to address whether technological innovations such as contact force sensing (CFS) can improve acute and long-term ablation outcomes of left ventricular papillary muscle (LV PAP) ventricular arrhythmias (VAs). BACKGROUND: Catheter ablation of LV PAP VAs has been less efficacious than another focal VAs. It remains unclear whether technological innovations such as CFS can improve acute and long-term ablation outcomes of LV PAP VA. METHODS: From January 2015 to December 2019, a total of 137 patients underwent LV PAP VA ablation. VA site of origin (SOO) was identified using activation and pace-mapping guided by intracardiac echocardiography. Radiofrequency energy (20 to 50 W for 60 to 90 s) was delivered by irrigated catheter with or without CFS. We defined acute success as complete suppression of targeted VA ≥30 min post ablation and clinical success as ≥80% VA burden reduction at outpatient follow-up. RESULTS: VA manifested as premature ventricular complexes in 98 (71%), nonsustained ventricular tachycardia in 18 (13%), sustained ventricular tachycardia in 12 (9%) and premature ventricular complexes induced ventricular fibrillation in 9 (7%). VA SOO was anterolateral PAP in 51 (37%), posteromedial PAP in 73 (53%), and both PAPs in 13 (10%). VAs were targeted using CFS in 97 (71%) and non-CFS in 40 (29%). After a single procedure, acute success was achieved in 130 (95%) and clinical success was achieved in 112 (82%); neither was impacted by VA SOO and/or CFS. Complications occurred in 5 patients (3.6%). CONCLUSION: Independent of CFS technology, intracardiac echocardiography-guided catheter ablation is highly efficacious and may be considered as first-line therapy in the management of LV PAP VA.

Percutaneous Retrieval of a Watchman Device from the Left Ventricle Using a Transarterial Approach.

Left atrial appendage closure device embolization is a rare yet serious complication. The location of the embolized device is a major determinant of the retrieval approach, percutaneous or surgical. This paper presents the case of Watchman device embolization in the left ventricle, which was retrieved percutaneously by using a transarterial approach. (Level of Difficulty: Intermediate.).

Contemporary Updates on Clinical Trials of Antiangiogenic Agents in the Treatment of Glioblastoma Multiforme.

Glioblastoma multiforme (GBM) has the highest rate of vascular proliferation among solid tumors. Angiogenesis is the central feature of rapid tumor growth in GBM and therefore remains an appealing therapeutic target in the treatment of these highly malignant tumors. Antiangiogenic therapy is emerging as an important adjuvant treatment. Multiple antiangiogenic agents targeting various sites in vascular endothelial growth factor (VEGF) and integrin pathways have been tested in clinical trials of newly diagnosed and recurrent GBMs. These include bevacizumab, enzastaurin, aflibercept, cediranib, and cilengitide. In this review, we discuss the current status and challenges facing clinical application of antiangiogenic treatment including anti-VEGF therapy and integrin pathway agents' therapy in glioblastoma. Here, we highlight a strong biologic rationale for this strategy, also focusing on integrin pathways. PubMed-indexed clinical trials published in English on antiangiogenic treatment of glioblastomas in the past 5 years were reviewed. The results of the current clinical trials of these agents are presented.

Long-Term Outcome of Catheter Ablation for Treatment of Bundle Branch Re-Entrant Tachycardia.

OBJECTIVES: This study reports the long-term outcome of patients with bundle branch re-entrant tachycardia (BBRT) who underwent catheter ablation for ventricular tachycardia (VT). BACKGROUND: BBRT is an uncommon mechanism of VT. Data on long-term outcomes of patients with BBRT treated with catheter ablation are insufficient. METHODS: Between 2005 and 2016, 32 patients had a sustained VT due to a bundle branch re-entrant mechanism. Diagnosis of BBRT was established per standard published criteria. RESULTS: The mode of presentation was syncope in 17 patients (53%) and palpitations in 15 (47%). BBRT was inducible in all subjects, and successful ablation of the right bundle branch in 19 patients (59%) or the left bundle branch in 13 patients (41%) was performed. During follow-up of 95 ± 36 months, 6 patients (19%) died, 3 of progressive heart failure and 3 of noncardiac causes. Recurrent VT due to BBRT did not occur in any patient. At baseline, 25 patients (78%) had a prolonged HV interval (>55 ms) and 7 (22%) had a normal HV interval (≤55 ms). In patients with a normal HV interval, there was only 1 death (due to malignancy), and no one developed heart block during 90 ± 36 months of follow-up. Ten patients (31%) had normal left ventricular (LV) function (LV ejection fraction ≥50%), and 22 (69%) had depressed LV function (LV ejection fraction <50%). No deaths were recorded in patients with normal LV function (5 with no implantable cardioverter-defibrillator) compared with 6 deaths among patients with depressed LV function (n = 22; p = 0.07). CONCLUSIONS: Radiofrequency ablation of the bundle branch is an effective therapy for treatment of BBRT. Sustained BBRT can be seen in patients with normal LV systolic function and HV interval with excellent long-term outcomes after ablation.

Effects of rosiglitazone on lipids, adipokines, and inflammatory markers in nondiabetic patients with low high-density lipoprotein cholesterol and metabolic syndrome.

BACKGROUND: PPAR-gamma agonists improve insulin sensitivity and glycemic control in type 2 diabetes and may reduce atherosclerosis progression. Thus, PPAR-gamma agonists may be an effective therapy for metabolic syndrome. However, the full spectrum of potentially antiatherogenic mechanisms of PPAR-gamma agonists have not been fully tested in nondiabetic patients with metabolic syndrome. METHODS AND RESULTS: We performed a prospective, double-blinded, placebo-controlled study of 60 nondiabetic subjects with low high-density lipoprotein cholesterol (HDL-C) level and metabolic syndrome to rosiglitazone 8 mg daily or placebo for 12 weeks. We found no significant effect of rosiglitazone on HDL-C (+5.5% versus +5.8%, P=0.89), and an increase in total cholesterol (+8% versus -1%; P=0.03). Nevertheless, rosiglitazone significantly increased adiponectin (+168% versus +25%; P<0.001), and lowered resistin (-6% versus +4%; P=0.009), C-reactive protein (-32% versus +36%, P=0.002), interleukin (IL)-6 (-22% versus +4%, P<0.001), and soluble tumor-necrosis factor-alpha receptor-2 (-5% versus +7%, P<0.001). CONCLUSIONS: These findings suggest that rosiglitazone, presumably through its PPAR-gamma agonist properties, has direct effects on inflammatory markers and adipokines in the absence of favorable lipid effects. These findings may help explain the mechanism underlying the possible antiatherosclerotic effects of rosiglitazone.