A stepwise external cardioversion protocol for atrial fibrillation to maximize acute success rate.

AIMS: Cardioversion is a very commonly performed procedure for persistent atrial fibrillation (AF). However, there is no well-defined protocol to address failed external electrical direct current cardioversion. The aim of the study is to test the efficacy of a pre-defined stepwise cardioversion protocol for patients with persistent AF of ≤12 months. Success was the achievement of sinus rhythm. METHODS AND RESULTS: The study population included patients with persistent AF of ≤12 months duration requiring rhythm management. Patients were offered cardioversion using a pre-defined stepwise protocol using different electrode placement locations, applying compression at end of expiration, and higher energy delivered simultaneously through two defibrillators. : A total of 414 patients were included in the study, of which 362 (87.4%) required a single successful cardioversion. The remaining 52 (12.5%) patients required additional cardioversion attempts using the stepwise cardioversion protocol with an overall success rate of 99.3%. Two simultaneous defibrillators were required in 14 patients (3.4%). Patients with multiple cardioversions (13.5%) experienced more local skin irritation and pain compared with patients with single cardioversion (13.5% vs. 3.5%, P = 0.004). The predictor for the need for multiple cardioversion attempts is high body mass index, while high transthoracic impedance is associated with failed cardioversion. No major complications were observed during the study. CONCLUSION: The stepwise cardioversion protocol has a high success rate of >99% and can be safely performed in outpatient or inpatient settings.

Randomized trial comparing the effectiveness of internal (through implantable cardioverter defibrillator) versus external cardioversion of atrial fibrillation.

PURPOSE: When patients with implantable cardioverter defibrillators (ICD) develop symptomatic atrial fibrillation (AF), external direct current cardioversion (EDCCV), as well as internal cardioversion using their ICD, are the options available. It is currently unknown which of these two methods are more effective. We compared the effectiveness of EDCCV versus internal cardioversion to terminate AF in patients with a single-coil ICD. METHODS: This randomized controlled trial (clinicaltrial.gov NCT03164395) enrolled consecutive patients with a single-coil ICD that presented with symptomatic AF of less than 1-year duration. They received either the maximum energy internal shock through the ICD or an EDCCV using transcutaneous pads of 200 J. The primary endpoint was a successful conversion to sinus rhythm after one shock. Crossover was permitted if the first shock was unsuccessful. RESULTS: Thirty-one patients were enrolled in the study, including 16 in the internal ICD cardioversion group. The study included patients with a mean age of 59.5 ± 16.0 years, 41.9% females, median AF duration 1 month (interquartile range 1-3), 45.2% non-ischemic cardiomyopathies, mean EF 28.6 ± 16.0%, and 45.2% biventricular ICD. There were no significant differences in baseline clinical characteristics between the two groups. In the internal cardioversion group, 5/16 patients (31.3%) met the primary endpoint versus 14/15 (93.3%) in the EDCCV group, p < 0.001. All patients that failed the first shock were subsequently cardioverted externally. CONCLUSION: Among patients with a single-coil ICD and symptomatic AF of less than 1 year, external direct current cardioversion is much more effective than internal shock through the ICD.

Single incision technique for implantation of subcutaneous implantable cardioverter defibrillators.

BACKGROUND: Subcutaneous implantable cardioverter defibrillators (S-ICDs) have gained increasing popularity because of certain advantages over transvenous ICDs. However, while conventional ICDs require a single surgical incision to implant, S-ICDS need two or three incisions, making them less appealing. OBJECTIVE: This study sought out to investigate the feasibility of using a single-incision technique to implant S-ICDs. METHODS: Patients qualifying for S-ICDs were considered for a single incision. A single incision is performed by making a left inframammary incision and then the subcutaneous tissue is dissected medially toward the lower sternum. Two sutures are placed in the fascia in the xiphoid area to anchor the lead and a tunneling tool is used to dissect the tissue to place the lead parallel to the sternum. Then subcutaneous tissues are dissected down the lateral chest wall over the muscle fascia to create the pulse generator pocket in the vicinity of the fifth and sixth intercostal spaces and near the mid-axillary line. RESULTS: Eleven patients (six males and five females) successfully underwent S-ICD implantation with a single incision without acute complications (64% for primary prevention). The mean age is 47.4 ± 15.8 years. There were no lead dislodgements, inappropriate shocks, or any other issues during a median follow-up of 10 months (interquartile range 5-17). One patient had a successful appropriate shock for ventricular fibrillation about one year after device implant. CONCLUSIONS: A single incision for subcutaneous ICDs is feasible and safe in our early experience.

Comparison of Complications of Catheter Ablation for Ventricular Arrhythmias in Adults With Versus Without Structural Heart Disease.

Catheter ablation (CA) is an effective treatment for ventricular arrhythmias (VA), with a potential for complications. The presence of structural heart disease (SHD) is associated with a higher complication rate although there is no data comparing CA of VA between patients with SHD and those without. We aimed to compare trends, morbidity, and mortality associated with real world practice of CA for VA (ventricular tachycardia and premature ventricular contraction) based on the presence of SHD. Using weighted sampling in the National Inpatient Sample database, we collected and compared characteristics and outcomes of patients with or without SHD that underwent CA of VA. Among 34,907 patients that underwent CA for VA (1999-2013), 18,014 (51.6%) had SHD. Major and all complications occurred among 1,135/18,014 (6.3%) and 2139/18,014 (11.9%) patients with SHD respectively compared with 355/16,893 (2.1%) and 739/16,893 (4.4%) for patients without SHD, p < 0.001 for both comparisons. Furthermore, 452/18,014 (2.51%) with SHD died versus 20/16,893 (0.12%) without SHD, p < 0.001. Heart failure was associated with an odds ratio (OR) of 3.09 for major complications (95%CI: 1.53-6.27, p = 0.002) for patients with SHD while coronary artery disease OR for major complications was 2.47 (95%CI: 1.44-4.23, p = 0.001) for patients without SHD. There was a significant increase in major complications over the 15-year study period in patients with SHD, p < 0.001. In conclusion, the presence of SHD during CA for VA increased the complication rate of major and any complications by approximately threefold for both and the hospital mortality by >20-fold compared with patients without SHD.

Sex differences in complications of catheter ablation for atrial fibrillation: results on 85,977 patients.

PURPOSE: Catheter ablation (CA) is an effective treatment for atrial fibrillation (AF). The differences in complication rates and outcomes between women and men remain poorly studied. We aimed to study the sex differences in morbidity and mortality associated with CA in AF. METHODS: Using weighted sampling from the National Inpatient Sample database, women and men with a primary diagnosis of AF and a primary procedure of CA (2004-2013) were identified. We compared the following outcomes based on the sex: (1) major complications [post-procedure transfusion, cardiac drain or surgery, pulmonary embolism, cerebrovascular accident, major cardiac events, kidney failure requiring dialysis, and sepsis], (2) overall complications (minor and/or major complications), and (3) in-hospital mortality. RESULTS: Among 85,977 patients who underwent CA for AF, 27821 (32.4%) were women. Overall complications were more frequent among women versus among men (12.4% versus 9.0%; p < 0.001), as well as major complications (4.7% versus 2.7%; p < 0.001). However, there was no difference in mortality (0.3% versus 0.2%; p = 0.22). After adjusting for other factors, women were more likely than men to have major complication (odds ratio 1.48, 95% CI 1.21-1.82; p < 0.001). Prior CABG was associated with lower risk of major complications in both sexes (odds ratio in the overall cohort 0.27, 95% CI 0.12-0.61; p = 0.002), mostly driven by the reduction in tamponade and pericardial drain. CONCLUSIONS: Among patients who underwent catheter ablation for AF, the female sex was associated with higher rate of complications compared to male but no difference in mortality. Prior CABG was associated with a significant reduction of major complications in both sexes.

Junctional ectopic rhythm after AVNRT ablation: An underrecognized complication.

BACKGROUND: Ablation is an effective treatment for atrioventricular nodal reentrant tachycardia (AVNRT). The occurrence of junctional ectopic rhythm (JER), including junctional ectopic tachycardia, following AVNRT ablation has been described as an extremely rare phenomenon, but may be underestimated. We aimed to determine the incidence of JER following AVNRT ablation within our institution, as well as that reported in the literature via an extensive review. METHODS: We reviewed our adult ablation institutional experience for the occurrence of JER after AVNRT ablation from 2009 to 2016. Additionally, we conducted an extensive literature search using different databases looking for AVNRT ablation case series. The individually reported complications of these studies were reviewed, with a primary endpoint defined as the occurrence of JER shortly after AVNRT ablation. The study was approved by our institutional review board. RESULTS: Our institutional data revealed 6/126 patients (prevalence 4.8%) developed non-preexisting JER post-AVNRT ablation. Four patients were asymptomatic. Two patients had persistent symptoms lasting over a year, with one patient requiring repeat ablation. The literature review included 149 adult and pediatric studies. There were three cases of reported JER, out of a total of 37,541 patients (31,768 adults and 5,773 pediatric; prevalence 0.008%). The three JER patients were pediatric, and all required further therapeutic intervention. CONCLUSION: JER might be an underreported complication of AVNRT ablation. It seems most often to be transient and self-limited, occurring days to weeks after ablation, but may also be debilitating, requiring more aggressive management.

Oral factor Xa inhibitors for the treatment of left ventricular thrombus: a case series.

Left ventricular thrombus (LVT) formation usually necessitates short term anticoagulation for thrombus resolution and to prevent embolic events. Historically, vitamin K antagonist therapy has been the treatment of choice. However, with the advent of direct acting anticoagulants, their role in the management of LVT is not clear. Patients were included if they had received rivaroxaban or apixaban for more than 1 day for LVT documented on imaging. The primary objective was resolution of LVT at 3 months based on assessment by an independent cardiologist review of initial and subsequent imaging results. The principle safety objective was to assess major or clinically relevant non-major bleeding using GUSTO, TIMI, and BARC bleeding criteria. During the 2-year study period seven patients were treated with rivaroxaban and three with apixaban. Two patients who had received apixaban and one on rivaroxaban were lost to follow up. In those with an initial and follow-up ECHO (n = 6) the median time to follow up imaging was 214 (IQR 33-414) days and complete LVT resolution was observed in 83% of patients. One patient on rivaroxaban had a bleeding events that was minimal (TIMI), Type 2 (BARC), or classified as mild (GUSTO) due to pulmonary hemorrhage. In those deemed not to be a candidate for vitamin K antagonist the use of rivaroxaban or apixaban may be a considered in the treatment of LVT. Further research in this area is needed to assess the efficacy and safety of using FXAI for treatment of LVT.

Use of adenosine to shorten the post ablation waiting period for cavotricuspid isthmus-dependent atrial flutter.

BACKGROUND: Dormant conduction unmasked by adenosine predicts clinical recurrences of cavotricuspid isthmus (CTI) dependent atrial flutter following catheter ablation. Conventional practice involves a waiting period of 20 to 30 minutes after achievement of a bidirectional line of block (BDB) to monitor for recovery of conduction. OBJECTIVE: Assess whether abolition of dormant conduction with adenosine immediately after CTI ablation and BDB can predict the lack of CTI conduction recovery during the following 30 minutes. METHODS: Consecutive patients undergoing catheter ablation for CTI-dependent atrial flutter were studied. Following the completion of CTI ablation and documentation of BDB, adenosine (≥12 mg IV) was administered immediately. In cases of dormant conduction, the CTI was ablated again until its abolition. After the achievement of BDB without dormant conduction, spontaneous CTI reconnection during the following 30 minutes and dormant conduction with adenosine at 30 minutes were evaluated. RESULTS: A CTI block was achieved in 171 patients. Nine patients (5.3%) had dormant conduction across the CTI immediately after ablation and BDB, and required further ablation. Two patients (1.2%) had subsequent spontaneous time-dependent reconnection within 30 minutes. Two other patients (1.2%) developed late dormant conduction with adenosine at 30 minutes. All 4 patients underwent further ablation. CONCLUSION: A negative adenosine challenge immediately after CTI ablation with bidirectional block, or after abolition of dormant conduction with further ablation, strongly predicted the absence of subsequent spontaneous reconnection within 30 minutes. Based on these results, the conventional waiting period is unnecessary in 97.6% patients without dormant conduction after CTI-dependent flutter ablation.

Acute Effects of Implantable Cardioverter-Defibrillator Shocks on Biomarkers of Myocardial Injury, Apoptosis, Heart Failure, and Systemic Inflammation.

BACKGROUND: Implantable cardioverter-defibrillator (ICD) shocks are potentially associated with myocardial injury, altered hemodynamics, apoptosis, and inflammatory signaling. Their precise cellular impact can be explored after defibrillation testing (DFT) via biomarkers. We evaluated changes in biomarkers after ICD shocks during DFT. METHODS: We prospectively enrolled outpatients presenting for first implantation of a cardiac device. Biomarkers indicative of myocardial injury, inflammation, and apoptosis were measured before and after implantation, and compared between patients receiving DFT (DFT+) to those not (DFT-). RESULTS: Sixty-three patients were enrolled, 40 in the DFT+ group and 23 in the DFT- group. Average levels of troponin I, hsCRP, Calprotectin, N-terminal pro B-type natriuretic peptide (NTproBNP), and sFas increased by >50% after cardiac device implantation compared to baseline. Increase in troponin never exceeded the 50-fold upper limit of normal (2 ng/mL). Troponin trended higher in the DFT+ group at 8 hours (median 0.18 ng/mL, interquartile range [IQR] 0.11-0.48) versus the DFT- group (0.10 ng/mL, IQR 0.06-0.28, P = 0.0501); NTproBNP had a similar trend (P = 0.0581). sFas significantly increased in the DFT+ group from baseline (median 4663 pg/mL, IQR 2908-5679) to 24 hours (5039 pg/mL, IQR 3274-6261; P = 0.0338) but not in the DFT- group (P = 0.4705). CONCLUSION: DFT testing is associated with acutely increased plasma levels of troponin and sFas, a biomarker of apoptosis, along with a trend toward higher NTproBNP.

Management of abdominal compartment syndrome in a very low birth weight neonate using Penrose drains and subsequent management of abdominal-wall defects.

Percutaneous drainage of the peritoneal cavity has been recently evaluated for the treatment of perforated viscous in the very low birth weight (VLBW) neonate and percutaneous decompression for abdominal compartment syndrome (ACS) has been studied in older patient populations. This is the first reported case of using this technique to treat ACS in a VLBW neonate.

Microwave modeling and validation in food thawing applications.

Developing temperature fields in frozen cheese sauce undergoing microwave heating were simulated and measured. Two scenarios were investigated: a centric and offset placement on the rotating turntable. Numerical modeling was performed using a dedicated electromagnetic Finite Difference Time Domain (FDTD) module that was two-way coupled to the PHYSICA multiphysics package. Two meshes were used: the food material and container were meshed for the heat transfer and the microwave oven cavity and waveguide were meshed for the microwave field. Power densities obtained on the structured FDTD mesh were mapped onto the unstructured finite volume method mesh for each time-step/turntable position. On heating for each specified time-step the temperature field was mapped back onto the FDTD mesh and the electromagnetic properties were updated accordingly. Changes in thermal/electric properties associated with the phase transition were fully accounted for as well as heat losses from product to cavity. Detailed comparisons were carried out for the centric and offset placements, comparing experimental temperature profiles during microwave thawing with those obtained by numerical simulation.