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10,200 | Sudden Death After Transcatheter Aortic Valve Implantation. Are Bradyarrhythmias Always The Cause? | Transcatheter Aortic-Valve Implantation (TAVI) is considered to be highly effective in the treatment of high-risk patients with severe aortic stenosis. After TAVI, the rate of pacemaker implantation is 6.5%-40%. Some reports of sudden death after TAVI are mostly attributed to bradyarrhythmias. We report the case of three patients who experienced sudden cardiac death or aborted sudden cardiac death after TAVI. All patients were affected from ischemic heart disease with an ejection fraction of approximately 40% and underwent pacemaker implantation (PM) after the procedure due to 1rst degree atrioventricular block (AV) and left bundle branch block (LBBB). One of the patients died suddenly 30 days after the procedure. The PM interrogation revealed many episodes of non sustain ventricular tachycardias (NSVT) and one episode of ventricular fibrillation (VF) that led to death. The other two patients had syncope and during PM interrogation episodes of ventricular tachycardia >12 sec were recorded. Patients affected by ischemic heart disease undergoing TAVI, especially with borderline coronary lesions should receive particular attention in order to avoid potentially lethal ventricular arrhythmias. In addition, the physiopathologic mechanism of sudden arrhythmic death in these patients needs to be clarified. |
10,201 | Heart Failure With Reduced Ejection Fraction And A Narrow QRS Complex: Combination Of A Subcutaneous Defibrillator With Cardiac Contractility Modulation. | Cardiac contractility modulation (CCM) is a relatively new electrical therapy for heart failure patients with reduced ejection fraction. The majority of patients eligible for CCM will also need an implantable cardioverter-defibrillator (ICD). To-date, three pacing electrodes are mandatory for CCM therapy because the current CCM signal delivery algorithm requires sequential intracardiac sensing of a p-wave, followed by appropriately timed ventricular activation by the two ventricular septal leads. As there is no device combining CCM with ICD functions, most CCM patients will need multiple intracardiac electrodes, which increase the cumulative risk for complications such as systemic infections, thrombosis of central venous lines, insulation failures or lead fractures. The long-term complications associated with trans-venous ICD leads have led to the development of a totally subcutaneous implantable cardioverter-defibrillator (S-ICD). In this essay the two technologies CCM and S-ICD are reviewed. Additionally, we present their successful combination on the basis of a case report on the first patient receiving both devices. |
10,202 | A Novel Approach to Improve Time to First Shock in Prehospital STEMI Complicated by Ventricular Fibrillation. | Lethal cardiac arrhythmias such as ventricular fibrillation and pulseless ventricular tachycardia (VF/pVT) complicate up to 6% of all out-of-hospital STEMIs. Typically, paramedics respond to this by applying defibrillation pads and delivering a shock as soon as possible. A recently introduced "pads-on" protocol directed paramedics to apply defibrillation pads to all STEMI patients (regardless of clinical stability) with the aim of decreasing time to first shock. In this article we present two cases of prehospital STEMI complicated by VF to illustrate times to first shock for the two different protocols. One case each of a STEMI complicated by VF before implementation of the pads-on protocol and after the implementation of the protocol is presented. An important difference in the time to first shock is noted between the two patients with STEMI complicated by VF. While it took 2 min 43 s for the pads-off patient to be defibrillated, only 27 s elapsed before the pads-on patient was defibrillated. These two cases demonstrate that the application of defibrillation pads immediately following the diagnosis of prehospital STEMI has the potential to decrease the time to shock in patients suffering VF/pVT. |
10,203 | Advances in the pharmacologic treatment of ventricular arrhythmias. | Despite many advances in nonpharmacologic management of ventricular arrhythmias, antiarrhythmic drugs remain important in both the acute conversion and chronic prevention of ventricular arrhythmias.</AbstractText>Key trials related to antiarrhythmic drug use are reviewed, emphasizing the impact of recent discoveries. Sodium channel blockers are discussed with an emphasis on recently identified specialized uses. Beta blockers, amiodarone, sotalol, and dofetilide are discussed together in the context of structural heart disease, because they do not increase mortality in this group of patients. Other medications found to reduce ventricular arrhythmia burden are discussed last.</AbstractText>Since most patients with ventricular arrhythmias have structural heart disease, pharmacologic treatment is limited to amiodarone, d-,l-sotalol, and dofetilide (off-label indication), in conjunction with defibrillator implantation. While amiodarone has superior reduction in arrhythmias, its long-term extracardiac toxicities can cause significant morbidity. A trial of sotalol is reasonable if there are no contraindications, recognizing that over 20% of patients have to discontinue it because of adverse effects. Beta blockers are first line therapy for most patients. Genetic testing is particularly informative regarding treatment approach in long QT syndrome, Brugada syndrome, and catecholaminergic polymorphic VT. Research should continue to focus on developing more effective antiarrhythmic medications with less long-term toxicity.</AbstractText> |
10,204 | A review on atrioventricular junction ablation and pacing for heart rate control of atrial fibrillation. | Atrioventricular junction ablation with permanent pacemaker implantation is a highly effective treatment approach in patients with atrial fibrillation and high ventricular rates resistant to other treatment modalities, especially in the elderly or those with severe comorbidities. Compared with pharmacological therapy alone, the so-called "ablate and pace" approach offers the potential for more robust control of ventricular rate. Atrioventricular junction ablation and pacing strategy is associated with improvement in symptoms, quality of life, and exercise capacity. Given the close relationship between atrial fibrillation and heart failure, there is a particular benefit of such a rate control in patients with atrial fibrillation and reduced systolic function. There is increasing evidence that cardiac resynchronization therapy devices may be beneficial in selected populations after atrioventricular junction ablation. The present review article focuses on the current recommendations for atrioventricular junction ablation and pacing for heart rate control in patients with atrial fibrillation. The technique, the optimal implantation time, and the proper device selection after atrioventricular junction ablation are also discussed. |
10,205 | Is cardiac resynchronisation therapy feasible, safe and beneficial in the very elderly? | To evaluate whether cardiac resynchronisation therapy (CRT) implantation was feasible and safe in octogenarians and the association with symptoms.</AbstractText>Consecutive patients undergoing CRT implantation were recruited from two UK centers. Patients grouped according to age: < 80 & ≥ 80 years. Baseline demographics, complications and outcomes were compared between those groups.</AbstractText>A total of 439 patients were included in this study, of whom 26% were aged ≥ 80 years. Octogenarians more often received cardiac resynchronization therapy pacemaker in comparison to cardiac resynchronisation therapy-defibrillator. Upgrade from pacemaker was common in both groups (16% < 80 years vs. 22% ≥ 80 years, P = NS). Co-morbidities were similarly common in both groups (overall diabetes: 25%, atrial fibrillation: 23%, hypertension: 45%). More patient age ≥ 80 years had significant chronic kidney disease (CKD, estimated glomerular filtration rate < 45 mL/min per 1.73 m(2), 44% vs. 22%, P < 0.01). Overall complication rates (any) were similar in both groups (16% vs. 17%, P = NS). Both groups demonstrated symptomatic benefit. One-year mortality rates were almost four fold greater in octogenarians as compared with the younger cohort (13.9% vs. 3.7%, P < 0.01).</AbstractText>CRT appears to be safe in the very elderly despite extensive co-morbidity, and in particular frequent severe CKD. Symptomatic improvement appears to be meaningful. Strategies to increase the appropriate identification of elderly patients with CHF who are potential candidates for CRT are required.</AbstractText> |
10,206 | Defective recovery of QT dispersion following transcatheter aortic valve implantation: frequency, predictors and prognosis. | Corrected QT dispersion (cQTD) has been correlated with non-uniform ventricular repolarisation and increased mortality. In patients with aortic stenosis, cQTD has been shown improved after surgical valve replacement, but the effects of transcatheter aortic valve implantation (TAVI) are unknown. Therefore, we sought to explore the frequency, predictors and prognostic effects of defective cQTD recovery at 6 months after TAVI.</AbstractText>A total of 222 patients underwent TAVI with the Medtronic-CoreValve System between November 2005 and January 2012. Patients who were on class I or III antiarrhythmics or on chronic haemodialysis or who developed atrial fibrillation, a new bundle branch block or became pacemaker dependent after TAVI were excluded. As a result, pre-, post- and follow-up ECG (median: 6 months) analysis was available in 45 eligible patients. Defective cQTD recovery was defined as any progression beyond the baseline cQTD at 6 months.</AbstractText>In the 45 patients, the mean cQTD was 47 ± 23 ms at baseline, 45 ± 17 ms immediately after TAVI and 40 ± 16 ms at 6 months (15% reduction, P = 0.049). Compared to baseline, cQTD at 6 months was improved in 60% of the patients whereas defective cQTD recovery was present in 40%. cQTD increase immediately after TAVI was an independent predictor of defective cQTD recovery at 6 months (per 10 ms increase; OR: 1.89, 95% CI: 1.15-3.12). By univariable analysis, defective cQTD recovery was associated with late mortality (HR: 1.52, 95% CI: 1.05-2.17).</AbstractText>Despite a gradual reduction of cQTD after TAVI, 40% of the patients had defective recovery at 6 months which was associated with late mortality. More detailed ECG analysis after TAVI may help to avoid late death.</AbstractText> |
10,207 | Initial experience of subcutaneous implantable cardioverter defibrillators in Singapore: a case series and review of the literature. | Transvenous implantable cardioverter defibrillators are a type of implantable cardiac device. They are effective at reducing total and arrhythmic mortality in patients at risk of sudden cardiac death. Subcutaneous implantable cardioverter defibrillators (S-ICDs) are a new alternative that avoids the disadvantages of transvenous lead placement. In this case series, we report on the initial feasibility and safety of S-ICD implantation in Singapore. |
10,208 | Sudden Cardiac Death Despite a Functional Cardioverter-Defibrillator: The Case for Early and Aggressive Therapy for Ventricular Tachycardia in Selected Patients. | We present three cases within 11 months at a single institution of sustained VT that fell below the programmed detection rate of the patients' implantable cardioverter-defibrillators (ICDs), two of which continued until converting to an agonal VF that did not meet criteria for detection, and a third case that could not be successfully defibrillated after a prolonged period of VT. These episodes may be under-recognized due to the dependence of device diagnostic storage on programming and the post-mortem effort that is often required to review these events. Some patients, likely those with the most advanced heart failure, may not tolerate sustained ventricular tachycardia (VT) and may even die from ventricular arrhythmias without ever having a rhythm that meets detection criteria in a ventricular fibrillation (VF) zone. |
10,209 | Brugada syndrome: clinical presentation and genotype-correlation with magnetic resonance imaging parameters. | The purpose of the this study was to evaluate a possible genotype-phenotype correlation in BrS patients and to analyze possible associations with clinical events in affected patients. SCN5A gene encodes the alpha-subunit of the voltage-gated sodium channel NaV1.5. Its mutations are associated with a broad spectrum of hereditary arrhythmias such as long-QT syndrome, cardiac conduction diseases, and Brugada syndrome (BrS). Experimental studies have shown an interaction between SCN5A and cellular cytoskeleton, explaining its functional role in cellular integrity of heart cells.</AbstractText>Cardiovascular magnetic resonance was performed on 81 consecutive genetically screened BrS patients and 30 healthy controls. Left ventricular (LV) and right ventricular (RV) volumes and dimensions were assessed and compared with respect to the genotype. Brugada syndrome patients with an SCN5A mutation (16 patients; 20%) revealed significantly larger RV volumes, along with lower RV ejection fraction, than patients without a mutation or controls, indicating a more severe phenotype in patients with a mutation. Furthermore, patients with an SCN5A mutation showed significantly more often a spontaneous type 1 BrS-electrocardiogram (ECG). In multivariate analysis, the presence of a spontaneous type 1 BrS-ECG showed the strongest association with cardiac events. Receiver-operating characteristic curve analysis indicated good predictive performance of RV end-diastolic volume, RV end-systolic, and LV cardiac output (area under the curve = 0.81, 0.81, and 0.2), with respect to the presence of an SCN5A mutation.</AbstractText>Brugada syndrome patients with an SCN5A mutation reveal distinct changes in RV volumes and function when compared with those without an SCN5A mutation. Furthermore, mutation-positive patients have a higher likelihood of a spontaneous type 1 BrS-ECG, which is associated with a higher incidence of clinical events. Cardiovascular magnetic resonance may provide additional insight to distinguish between SCN5A mutation-positive and -negative BrS patients.</AbstractText>Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.</CopyrightInformation> |
10,210 | Effect of regulating airway pressure on intrathoracic pressure and vital organ perfusion pressure during cardiopulmonary resuscitation: a non-randomized interventional cross-over study. | The objective of this investigation was to evaluate changes in intrathoracic pressure (Ppl), airway pressure (Paw) and vital organ perfusion pressures during standard and intrathoracic pressure regulation (IPR)-assisted cardiopulmonary resuscitation (CPR).</AbstractText>Multiple CPR interventions were assessed, including newer ones based upon IPR, a therapy that enhances negative intrathoracic pressure after each positive pressure breath. Eight anesthetized pigs underwent 4 min of untreated ventricular fibrillation followed by 2 min each of sequential interventions: (1) conventional standard CPR (STD), (2) automated active compression decompression (ACD) CPR, (3) ACD+ an impedance threshold device (ITD) CPR or (4) ACD+ an intrathoracic pressure regulator (ITPR) CPR, the latter two representing IPR-based CPR therapies. Intrapleural (Ppl), airway (Paw), right atrial, intracranial, and aortic pressures, along with carotid blood flow and end tidal CO2, were measured and compared during each CPR intervention.</AbstractText>The lowest mean and decompression phase Ppl were observed with IPR-based therapies [Ppl mean (mean ± SE): STD (0.8 ± 1.1 mmHg); ACD (-1.6 ± 1.6); ACD-ITD (-3.7 ± 1.5, p < 0.05 vs. both STD and ACD); ACD-ITPR (-7.0 ± 1.9, p < 0.05 vs. both STD and ACD)] [Ppl decompression (mean ± SE): STD (-6.3 ± 2.2); ACD (-13.0 ± 3.8); ACD-ITD -16.9 ± 3.6, p < 0.05 vs. both STD and ACD); ACD-ITPR -18.7 ± 3.5, p < 0.05 vs. both STD and ACD)]. Interventions with the lower mean or decompression phase Ppl also demonstrated lower Paw and were associated with higher vital organ perfusion pressures.</AbstractText>IPR-based CPR methods, specifically ACD-ITPR, yielded the most pronounced reduction in both Ppl and Paw and resulted in the most favorable augmentation of hemodynamics during CPR.</AbstractText> |
10,211 | Right coronary cusp as a new window of ablation for pilsicainide-induced ventricular premature contractions in a patient with Brugada syndrome. | A previous study demonstrated that ventricular premature contractions (VPCs) and ventricular fibrillation (VF) are provoked during sodium channel blocker challenge tests in Brugada syndrome (BrS) patients (Morita et al., J Am Coll Cardiol 42:1624-1631, 2003). The right ventricular outflow tract (RVOT) is a major arrhythmogenic focus and isolated VPCs originating from that area have been shown to initiate VF (Kakishita et al., J Am Coll Cardiol 36:1646-1653, 2000). Here, we describe a case report of a BrS patient with VPCs arising from the posterior aspect of the RVOT epicardium which was provoked by a low-dose of pilsicainide, a pure sodium channel blocker, and was successfully ablated from the right coronary cusp. |
10,212 | A focused investigation of expedited, stack of three shocks versus chest compressions first followed by single shocks for monitored ventricular fibrillation/ventricular tachycardia cardiopulmonary arrest in an in-hospital setting. | In cases of in-hospital-witnessed ventricular fibrillation/ventricular tachycardia (VF/VT) arrest, it is unclear whether cardiopulmonary resuscitation prior to defibrillation attempt or expedited stacked defibrillation attempt is superior.</AbstractText>Retrospective, observational study of all admitted patients with continuous cardiac monitoring who suffered VF/VT arrest between July 2005 and June 2013. In the stacked shock period (2005-2008), institutional protocols advocated early defibrillation with administration of 3 stacked shocks with brief pauses between each single defibrillation attempt to confirm sustained VF/VT. During the initial chest compression period (2008-2011), the protocol was modified to perform a 2-minute period of chest compressions prior to each defibrillation, including the initial. In the modified stack shock period (2011-2013), for a monitored arrest, defibrillation attempts were expedited with up to 3 successive shocks administered for persistent VF/VT. In unmonitored arrest, chest compressions and ventilations were initiated prior to defibrillation. The primary outcome measure was survival to hospital discharge.</AbstractText>Six hundred sixty-one cardiopulmonary arrests were recorded during the study period, with 106 patients (16%) representing primary VF/VT. The incidence of VF/VT arrest did not vary significantly between the study periods (P= 0.16) Survival to hospital discharge for all primary VF/VT arrest victims decreased, then increased significantly from the stacked shock period to initial chest compression period to modified stacked shock period (58%, 18%, 71%, respectively, P < 0.01). Specific group differences were significant between the initial chest compression versus the stacked and modified stacked shock groups (all P < 0.01).</AbstractText>Data suggest that monitored VF/VT should undergo expeditious defibrillation with use of stacked shocks.</AbstractText>© 2015 Society of Hospital Medicine.</CopyrightInformation> |
10,213 | Spanish Catheter Ablation Registry. 14th Official Report of the Spanish Society of Cardiology Working Group on Electrophysiology and Arrhythmias (2014). | This report presents the findings of the 2014 Spanish Catheter Ablation Registry.</AbstractText>For data collection, each center was allowed to choose freely between 2 systems: retrospective, requiring the completion of a standardized questionnaire, and prospective, involving reporting to a central database.</AbstractText>Data were collected from 85 centers. A total of 12 871 ablation procedures were performed, for a mean of 149.5±103 procedures per center. The ablation targets most frequently treated were atrioventricular nodal reentrant tachycardia (n=3026; 23.5%), cavotricuspid isthmus (n=2833; 22.0%), and atrial fibrillation (n=2498; 19.4%). The number of ablation procedures for ventricular arrhythmias was similar to that of 2013, but there was a slight increase in the treatment of all the ventricular substrates, especially those associated with idiopathic ventricular tachycardia and scarring following myocardial infarction. The overall success rate was 95%, the rate of major complications was 1.3%, and the mortality rate was 0.02%.</AbstractText>The 2014 registry shows that the number of ablation procedures performed continued its upward trend and that, overall, the success rate was high and the number of complications low. Ablation of complex conditions continued to increase.</AbstractText>Copyright © 2015 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.</CopyrightInformation> |
10,214 | Echocardiographic diastolic function assessment is of modest utility in patients with persistent and longstanding persistent atrial fibrillation. | Detection of concurrent diastolic dysfunction (DD) may be beneficial in patients with persistent and longstanding persistent atrial fibrillation (AF). The role of transthoracic echocardiography (TTE) in assessing DD in patients with AF has not been well characterized. We sought to determine the utility of TTE in detecting elevated left atrial pressure (LAP) in patients with persistent and longstanding persistent non-valvular AF using directly measured LAP as the reference standard.</AbstractText>We retrospectively studied 157 patients with persistent AF and preserved left ventricular ejection fraction who underwent pulmonary vein isolation (PVI). LAP was determined in conjunction with trans-septal puncture at the time of catheter ablation. TTE was performed 1 day after PVI and included two dimensional, pulse wave spectral Doppler and tissue Doppler assessments.</AbstractText>The clinical parameter that strongly correlated with elevated LAP is longstanding persistent AF. Four strongest TTE parameters identified to moderately correlate with LAP include 1. left atrial minimum volume (LAVmin), 2. peak velocity of early mitral diastolic inflow velocity (E), 3. pulmonary vein systolic flow velocity (PVS), and 4. ratio of early diastolic transmitral inflow velocity to mitral annular velocity at the lateral site (E/E' lateral).</AbstractText>Accurate assessment of diastolic dysfunction in patients with persistent and longstanding persistent AF is difficult using TTE. A combination of LAVmin, PVS, and E might be helpful to determine elevated LAP.</AbstractText> |
10,215 | Pharmacological treatment of cardiac glycoside poisoning. | Cardiac glycosides are an important cause of poisoning, reflecting their widespread clinical usage and presence in natural sources. Poisoning can manifest as varying degrees of toxicity. Predominant clinical features include gastrointestinal signs, bradycardia and heart block. Death occurs from ventricular fibrillation or tachycardia. A wide range of treatments have been used, the more common including activated charcoal, atropine, β-adrenoceptor agonists, temporary pacing, anti-digoxin Fab and magnesium, and more novel agents include fructose-1,6-diphosphate (clinical trial in progress) and anticalin. However, even in the case of those treatments that have been in use for decades, there is debate regarding their efficacy, the indications and dosage that optimizes outcomes. This contributes to variability in use across the world. Another factor influencing usage is access. Barriers to access include the requirement for transfer to a specialized centre (for example, to receive temporary pacing) or financial resources (for example, anti-digoxin Fab in resource poor countries). Recent data suggest that existing methods for calculating the dose of anti-digoxin Fab in digoxin poisoning overstate the dose required, and that its efficacy may be minimal in patients with chronic digoxin poisoning. Cheaper and effective medicines are required, in particular for the treatment of yellow oleander poisoning which is problematic in resource poor countries. |
10,216 | Comparative Analysis of Methods to Induce Myocardial Infarction in a Closed-Chest Rabbit Model. | To develop a rabbit model of closed-chest catheter-induced myocardial infarction. Background. Limitations of rodent and large animal models justify the search for clinically relevant alternatives.</AbstractText>Microcatheterization of the heart was performed in 47 anesthetized 3-4 kg New Zealand rabbits to test five techniques of myocardial ischemia: free coils (n = 4), interlocking coils (n = 4), thrombogenic gelatin sponge (n = 4), balloon occlusion (n = 4), and alcohol injection (n = 8). In order to limit ventricular fibrillation, an antiarrhythmic protocol was implemented, with beta-blockers/amiodarone before and xylocaine infusion during the procedure. Clinical, angiographic, and echographic data were gathered. End points included demonstration of vessel occlusion (TIMI flow grades 0 and 1 on the angiogram), impairment of left ventricular function at 2 weeks after procedure (by echocardiography), and pathologically confirmed myocardial infarction.</AbstractText>The best arterial access was determined to be through the right carotid artery. The internal mammary guiding catheter 4-Fr was selected as the optimal device for selective intracoronary injection. Free coils deployed prematurely and tended to prolapse into the aorta. Interlocking coils did not deploy completely and failed to provide reliable results. Gelatin sponge was difficult to handle, adhered to the catheter, and could not be clearly visualized by fluoroscopy. Balloon occlusion yielded inconsistent results. Alcohol injection was the most efficient and reproducible method for inducing myocardial infarction (4 out of 6 animals), the extent of which could be fine-tuned by using a coaxial balloon catheter as a microcatheter (0.52 mm) to achieve a superselective injection of 0.2 mL of alcohol. This approach resulted in a 20% decrease in LVEF and infarcted myocardium was confirmed histologically.</AbstractText>By following a stepwise approach, a minimally invasive, effective, and reproducible rabbit model of catheter-induced myocardial infarction has been developed which addresses the limitations of rodent experiments while avoiding the logistical and cost issues associated with large animal models.</AbstractText> |
10,217 | Spontaneous Coronary Artery Dissection with Cardiac Tamponade. | Spontaneous coronary artery dissection is a rare cause of acute coronary syndrome. Clinical presentation ranges from chest pain alone to ST-segment-elevation myocardial infarction, ventricular fibrillation, and sudden death. The treatment of patients with spontaneous coronary artery dissection is challenging because the disease pathophysiology is unclear, optimal treatment is unknown, and short- and long-term prognostic data are minimal. We report the case of a 70-year-old woman who presented with an acute ST-segment-elevation myocardial infarction secondary to a spontaneous dissection of the left anterior descending coronary artery. She was treated conservatively. Cardiac tamponade developed 16 hours after presentation. Repeat coronary angiography revealed extension of the dissection. Medical therapy was continued after the hemopericardium was aspirated. The patient remained asymptomatic 3 years after hospital discharge. To our knowledge, this is the first reported case of spontaneous coronary artery dissection in association with cardiac tamponade that was treated conservatively and had a successful outcome. |
10,218 | Brugada Syndrome Presenting as Polymorphic Ventricular Tachycardia-Ventricular Fibrillation Lasting 94 Seconds Recorded on an Ambulatory Monitor. | Cardiac arrhythmias are common causes of syncope. Brugada syndrome is an uncommon but serious genetic arrhythmia disorder that can be unmasked by medicines causing sodium channel blockade.</AbstractText>This report documents a case of Brugada syndrome and polymorphic ventricular tachycardia-ventricular fibrillation not initially recognized in a patient taking nortriptyline and experiencing syncope. It also illustrates one of the longest episodes of ventricular fibrillation recorded on an ambulatory monitor (94 seconds). Although the baseline electrocardiogram did not demonstrate a typical appearance for Brugada syndrome, provocative testing with flecainide in this patient with documented polymorphic ventricular tachycardia revealed a Brugada electrocardiogram pattern.</AbstractText>Vigilance should be maintained for arrhythmia substrates such as Brugada syndrome in patients with typical symptoms when they are prescribed membrane-active medicines. Long-term ambulatory rhythm monitors can provide useful information in these cases, especially when symptoms are infrequent.</AbstractText> |
10,219 | Effect of ICD Therapies on Mortality in the OMNI Trial. | Analyses from primary prevention trials on implantable cardioverter defibrillator (ICD) therapy have shown an association between shocks and increased mortality. Recent data suggest a similar association with antitachycardia pacing (ATP).</AbstractText>The OMNI study is an observational study of pacemaker and ICD use. We aim to examine associations between ICD therapies and mortality in this setting.</AbstractText>A total of 2,255 OMNI patients with ICDs were included. Treated episodes were classified as appropriate or inappropriate. Patients were assigned into 1 of 3 groups depending on whether the episode required ATP only, single shock, or multiple shocks, and then followed for all-cause mortality. Additionally, we aimed to determine the frequency with which inappropriate ATP precipitated ventricular arrhythmias that led to shock, since this has been suggested as a mechanism of harm.</AbstractText>Over a mean follow-up of 39 ± 19 months, there were a total of 470 deaths (21%). Compared to patients with no treated episodes, patients with appropriate therapy had greater risk of death. Hazard ratios were 1.46 (95% confidence interval [CI] 1.05-2.02; P = 0.023) for the ATP-only group, 2.11 (95% CI 1.51-2.96; P < 0.001) for the single-shock group, and 2.55 (95% CI 1.43-4.57; P = 0.002) for the multishock group. There was no significant association between any type of inappropriate therapy and increased mortality. We identified only 7 instances of inappropriate ATP precipitating ventricular arrhythmia resulting in shock.</AbstractText>Patients receiving appropriate therapy of all types had increased mortality compared to those with no episodes. Furthermore, inappropriate ATP rarely precipitates ventricular arrhythmias.</AbstractText>© 2015 Wiley Periodicals, Inc.</CopyrightInformation> |
10,220 | Long-term prognosis of early repolarization with J-wave and QRS slur patterns on the resting electrocardiogram: a cohort study. | The prognostic value of early repolarization with J waves and QRS slurs remains controversial. Although these findings are more prevalent in patients with idiopathic ventricular fibrillation, their ability to predict cardiovascular death has varied across studies.</AbstractText>To test the hypothesis that J waves and QRS slurs on electrocardiograms (ECGs) are associated with increased risk for cardiovascular death.</AbstractText>Retrospective cohort.</AbstractText>Veterans Affairs Palo Alto Health Care System.</AbstractText>Veterans younger than 56 years who had resting 12-lead electrocardiography, 90.5% of whom were men.</AbstractText>Electrocardiograms were manually measured and visually coded using criteria of 0.1 mV or greater in at least 2 contiguous leads. J waves were measured at the peak of an upward deflection or notch at the end of QRS, and QRS slurs were measured at the top of conduction delay on the QRS downstroke. Absolute risk differences at 10 years were calculated to study the associations between J waves or QRS slurs and the primary outcome of cardiovascular death.</AbstractText>Over a median follow-up of 17.5 years, 859 cardiovascular deaths occurred. Of 20 661 ECGs, 4219 (20%) had J waves or QRS slurs in the inferior and/or lateral territories; of these, 3318 (78.6%) had J waves or QRS slurs in inferior leads and 1701 (40.3%) in lateral leads. The upper bound of differences in risk for cardiovascular death from any of the J-wave or QRS slur patterns suggests that an increased risk can be safely ruled out (inferior, -0.77% [95% CI, -1.27% to -0.27%]; lateral, -1.07% [CI, -1.72% to -0.43%]).</AbstractText>The study consisted of predominantly men, and deaths could be classified as cardiovascular but not arrhythmic.</AbstractText>J waves and QRS slurs did not exhibit a clinically meaningful increased risk for cardiovascular death in long-term follow-up.</AbstractText>None.</AbstractText> |
10,221 | Lungs exposed to 1 hour warm ischemia without heparin before harvesting might be suitable candidates for transplantation. | The limiting factor for lung transplantation is the lack of donor organs. The usage of lungs from donation after cardiac death (DCD) would dramatically increase donor availability. In the present paper we wanted to investigate lungs exposed to 1 h of warm ischemia without heparin followed by flush-perfusion and cold storage compared to lungs harvested from heart beating donors (HBD) using standard harvesting technique.</AbstractText>Twelve Swedish domestic pigs were randomized into two groups. Six pigs (DCD group) underwent ventricular fibrillation and were then left untouched for 1 h after declaration of death. They did not receive heparin. The lungs were then harvested and flush-perfused with Perfadex® solution and the organs were stored at 8 °C for 4 h. Six pigs (HBD group) received heparin and the lungs were harvested and flush-perfused with Perfadex® solution and the organs were stored at 8 °C for 4 h. Lung function was evaluated, using ex vivo lung perfusion (EVLP), with blood gases at different oxygen levels, pulmonary vascular resistance (PVR), lung weight, and macroscopic appearance.</AbstractText>At FiO2 1.0, the PaO2 in the DCD group was 51.7 ± 2.0 kPa and in the HBD group 68.6 ± 2.4 kPa (p < 0.01). Significantly lower PVR levels were measured in the DCD group (372 ± 31 dyne x s/cm(5)) compared to the HBD group (655 ± 45 dyne x s/cm(5)) (p < 0.001). There was no significant difference between groups in weight, compliance or signs of pulmonary thrombosis or embolization.</AbstractText>It seems as if DCD lungs exposed to 1 h of warm ischemia before 4 h of cold storage has satisfying oxygenation capacity, low PVR, normal weight and no signs of thrombosis or embolization. According to our study it seems as lungs exposed to 1 h warm ischemia without heparin might be good candidates for transplantation.</AbstractText> |
10,222 | Potassium Channel Blockade Enhances Atrial Fibrillation-Selective Antiarrhythmic Effects of Optimized State-Dependent Sodium Channel Blockade. | The development of effective and safe antiarrhythmic drugs for atrial fibrillation (AF) rhythm control is an unmet clinical need. Multichannel blockers are believed to have advantages over single-channel blockers for AF, but their development has been completely empirical to date. We tested the hypothesis that adding K(+)-channel blockade improves the atrium-selective electrophysiological profile and anti-AF effects of optimized Na(+)-channel blockers.</AbstractText>Realistic cardiomyocyte-, tissue-, and state-dependent Na(+)-channel block mathematical models, optical mapping, and action potential recording were used to study the effect of Na(+)-current (INa) blockade with or without concomitant inhibition of the rapid or ultrarapid delayed-rectifier K(+) currents (IKr and IKur, respectively). In the mathematical model, maximal AF selectivity was obtained with an inactivated-state Na(+)-channel blocker. Combining optimized Na(+)-channel blocker with IKr block increased rate-dependent and atrium-selective peak INa reduction, increased AF selectivity, and more effectively terminated AF compared with optimized Na(+)-channel blocker alone. Combining optimized Na(+)-channel blocker with IKur block had similar effects but without IKr block-induced ventricular action potential prolongation. Consistent with the mathematical model, in coronary-perfused canine hearts, the addition of dofetilide (selective IKr blocker) to pilsicainide (selective INa blocker) produced enhanced atrium-selective effects on maximal phase 0 upstroke and conduction velocity. Furthermore, pilsicainide plus dofetilide had higher AF termination efficacy than pilsicainide alone. Pilsicainide alone had no statistically significant effect on AF inducibility, whereas pilsicainide plus dofetilide rendered AF noninducible.</AbstractText>K(+)-channel block potentiates the AF-selective anti-AF effects obtainable with optimized Na(+)-channel blockade. Combining optimized Na(+)-channel block with blockade of atrial K(+) currents is a potentially valuable AF-selective antiarrhythmic drug strategy.</AbstractText>© 2015 American Heart Association, Inc.</CopyrightInformation> |
10,223 | [Corrigendum] Effects of rotigaptide (ZP123) on connexin43 remodeling in canine ventricular fibrillation. | Mol Med Rep 12: [Related article:] 5746–5752, 2015; DOI: 10.3892/mmr.2015.4193 Following the publication of this article on-line ahead of print, an interested reader drew to our attention some anomalies associated with the presentation of Fig. 1. In the lower panel, the fourth image from the left resembled a mirror image representation of the image in the first panel; the fifth image from the left bore a marked resemblance to a section of the third image, albeit displaced at an angle and with a different magnification; and an internal office investigation drew our attention to the fact that the sixth image in the upper panel resembled a section of the image in the third panel, although rotated through 180°. |
10,224 | Practical Management Guide for Clinicians Who Treat Patients with Amiodarone. | Amiodarone, an iodinated benzofuran derivative with Class I, II, III, and IV antiarrhythmic properties, is the most commonly used antiarrhythmic drug used to treat supraventricular and ventricular arrhythmias. Appropriate use of this drug, with its severe and potentially life-threatening adverse effects, requires an essential understanding of its risk-benefit properties in order to ensure safety. The objective of this review is to afford clinicians who treat patients receiving amiodarone an appropriate management strategy for its safe use. The authors of this consensus management guide have thoroughly reviewed and evaluated the existing literature on amiodarone and apply this information, along with the collective experience of the authors, in its development. Provided are management guides on the intravenous and oral dosing of amiodarone, appropriate outpatient follow-up of patients taking the drug, its recognized adverse effects, and recommendations on when to consult specialists to help in patient management. All clinicians must be cognizant of the appropriate use, follow-up, and adverse reactions of amiodarone. The responsibility incurred by those treating such patients cannot be overemphasized. |
10,225 | A novel intra-operative, high-resolution atrial mapping approach. | A new technique is demonstrated for extensive high-resolution intra-operative atrial mapping that will facilitate the localization of atrial fibrillation (AF) sources and identification of the substrate perpetuating AF.</AbstractText>Prior to the start of extra-corporal circulation, a 8 × 24-electrode array (2-mm inter-electrode distance) is placed subsequently on all the right and left epicardial atrial sites, including Bachmann's bundle, for recording of unipolar electrograms during sinus rhythm and (induced) AF. AF is induced by high-frequency pacing at the right atrial free wall. A pacemaker wire stitched to the right atrium serves as a reference signal. The indifferent pole is connected to a steal wire fixed to subcutaneous tissue. Electrograms are recorded by a computerized mapping system and, after amplification (gain 1000), filtering (bandwidth 0.5-400 Hz), sampling (1 kHz) and analogue to digital conversion (16 bits), automatically stored on hard disk. During the mapping procedure, real-time visualization secures electrogram quality. Analysis will be performed offline.</AbstractText>This technique was performed in 168 patients of 18 years and older, with coronary and/or structural heart disease, with or without AF, electively scheduled for cardiac surgery and a ventricular ejection fraction above 40 %. The mean duration of the entire mapping procedure including preparation time was 9 ± 2 min. Complications related to the mapping procedure during or after cardiac surgery were not observed.</AbstractText>We introduce the first epicardial atrial mapping approach with a high resolution of ≥1728 recording sites which can be performed in a procedure time of only 9±2 mins. This mapping technique can potentially identify areas responsible for initiation and persistence of AF and hopefully can individualize both diagnosis and therapy of AF.</AbstractText> |
10,226 | Effects of Oxygen Concentrations on Postresuscitation Myocardial Oxidative Stress and Myocardial Function in a Rat Model of Cardiopulmonary Resuscitation. | Lipid peroxidation induced by free-radical species plays a prominent role in myocardial injury following ischemia and reperfusion. However, there is a lack of data in different oxygen concentrations on myocardial lipid peroxidation during the early phase of reperfusion. In this study, we investigated whether ventilation with medium or normal concentration of oxygen would decrease the severity of myocardial lipid peroxidation and postresuscitation myocardial dysfunction.</AbstractText>Prospective, randomized, controlled experimental study.</AbstractText>University-affiliated animal research institution.</AbstractText>Sixty-three healthy male Sprague-Dawley rats.</AbstractText>Animals were randomized into three groups: 1) 100% group, 2) 50% group, and 3) 21% group. Ventricular fibrillation was induced and untreated for 8 minutes, and defibrillation was attempted after 8 minutes of cardiopulmonary resuscitation. Ventilation with 100%, 50%, or 21% oxygen was initiated in all groups during cardiopulmonary resuscitation and 1 hour following the return of spontaneous circulation. Normoxic ventilation was maintained thereafter.</AbstractText>Myocardial function, including ejection fraction and myocardial performance index, were measured at baseline, 4, or 72 hours after resuscitation. Blood samples were drawn at baseline, 15 minutes, 1, 4, or 72 hours after resuscitation for the measurements of blood gas or biomarkers. Significantly better myocardial function and longer duration of survival were observed in the 50% group. Compared with the 21% and 100% groups, a mild hyperoxia and greater oxygen extraction with lower 8-iso-prostaglandin F2α were observed in the 50% group. Pearson correlation analysis confirmed that 8-iso-prostaglandin F2α was positively correlated with myocardial performance index at 4 hours postresuscitation.</AbstractText>In a rat model of cardiac arrest and resuscitation, ventilation with 50% inspired oxygen during early postischemic reperfusion phase contributed to a decreased lipid peroxidation and a better myocardial function and duration of survival.</AbstractText> |
10,227 | Galectin-3 levels in patients with hypertrophic cardiomyopathy and its relationship with left ventricular mass index and function. | Cardiac fibrosis is an important contributor to adverse left ventricular (LV) remodeling and arrhythmias in patients with hypertrophic cardiomyopathy (HCM). Galectin-3 (Gal-3) is a novel marker of cardiac fibrosis and inflammation. In this study, we investigated Gal-3 levels in patients with HCM and controls and assessed the relationship between Gal-3 level and echocardiographic indices using strain echocardiography in patients with HCM.</AbstractText>Forty patients with HCM in sinus rhythm and 35 healthy controls were prospectively enrolled in this case-control study. The HCM diagnosis was based on two-dimensional echocardiographic demonstration of a hypertrophied and non-dilated left ventricle (LV) with a wall thickness ≥15 mm in one or more LV myocardial segments in the absence of any cardiac or systemic disease capable of inducing LV hypertrophy. Patients with one of the followings were excluded: coronary artery disease, atrial fibrillation episodes on 24-h Holter electrocardiogram (ECG) monitoring, history of an invasive intervention to alleviate an LV outflow (LVOT) obstruction, inadequate image quality, renal disease, diabetes mellitus, hyperlipidemia, liver cirrhosis, and pulmonary fibrosis. Global LV longitudinal, circumferential strain and strain rates, peak torsion, and LV mass index (LVMI) of all subjects were assessed by echocardiography. Gal-3 levels were measured in all subjects.</AbstractText>Left ventricular global longitudinal strain (-13.37±4.6% vs. -18.93±2.5%, p<0.001) and strain rate (0.66±0.22 s-1 vs. 1.08±0.14 s-1, respectively; p<0.001) values were lower in patients with HCM than in controls. Gal-3 levels were significantly higher in patients with HCM than in controls (16.9±6.64 ng/mL vs. 13.21±3.42 ng/mL, p=0.005). Gal-3 levels were associated with the thickness of the interventricular septum (r=0.444, p=0.004) and LVMI (r=0.365, p=0.021); however, they were not associated with LV global longitudinal strain (p=0.42) or strain rate (p=0.28).</AbstractText>Gal-3 levels increased and were correlated with the degree of LV hypertrophy in patients with HCM. Gal-3 is not a good marker of decreased myocardial LV diastolic and systolic functions in these patients.</AbstractText> |
10,228 | Mild hypothermia preserves cerebral cortex microcirculation after resuscitation in a rat model of cardiac arrest. | Mild hypothermia improves the outcomes of comatose patients after cardiac arrest. Its neuroprotective mechanism is not fully understood. We investigated the effects of mild hypothermia on cerebral cortex microcirculation and cerebral oxygen extraction ratio.</AbstractText>Twenty-five rats were randomized into the hypothermic group (HT), normothermic group (NT) or the sham control group. Ventricular fibrillation was electrically induced and untreated for 8 min, followed by 8 min of precordial compressions and mechanical ventilations. The core temperature in the HT group was reduced to 33±0.5 °C at 14 min after ROSC with a combination of ice packs, an electrical fan and a cooling blanket. The temperature was maintained at 33 °C for 8h. Hemodynamics, arterial and jugular venous blood gases and cerebral cortex microcirculation were measured at baseline, 2, 4 and 8h after ROSC.</AbstractText>Microvascular flow index was significantly reduced in the NT and HT groups when compared with the SC group. A significant lesser reduction in microvascular flow index was observed in the HT group when compared with the NT group. Mild hypothermia reduced the cerebral oxygen extraction ratio after resuscitation when compared with the NT group.</AbstractText>Mild hypothermia improves the cerebral cortex microcirculatory blood supply/oxygen uptake mismatching after resuscitation. This may provide an additional cerebral protection.</AbstractText>Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
10,229 | Pulse Oximetry: A Non-Invasive, Novel Marker for the Quality of Chest Compressions in Porcine Models of Cardiac Arrest. | Pulse oximetry, which noninvasively detects the blood flow of peripheral tissue, has achieved widespread clinical use. We have noticed that the better the quality of cardiopulmonary resuscitation (CPR), the better the appearance of pulse oximetry plethysmographic waveform (POP). We investigated whether the area under the curve (AUC) and/or the amplitude (Amp) of POP could be used to monitor the quality of CPR.</AbstractText>Prospective, randomized controlled study.</AbstractText>Animal experimental center in Peking Union Medical Collage Hospital, Beijing, China.</AbstractText>Healthy 3-month-old male domestic swine.</AbstractText>34 local pigs were enrolled in this study. After 4 minutes of untreated ventricular fibrillation, animals were randomly assigned into two resuscitation groups: a "low quality" group (with a compression depth of 3cm) and a "high quality" group (with a depth of 5cm). All treatments between the two groups were identical except for the depth of chest compressions. Hemodynamic parameters [coronary perfusion pressure (CPP), partial pressure of end-tidal carbon dioxide (PETCO2)] as well as AUC and Amp of POP were all collected and analyzed.</AbstractText>There were statistical differences between the "high quality" group and the "low quality" group in AUC, Amp, CPP and PETCO2 during CPR (P<0.05). AUC, Amp and CPP were positively correlated with PETCO2, respectively (P<0.01). There was no statistical difference between the heart rate calculated according to the POP (FCPR) and the frequency of mechanical CPR at the 3rd minute of CPR. The FCPR was lower than the frequency of mechanical CPR at the 6th and the 9th minute of CPR.</AbstractText>Both the AUC and Amp of POP correlated well with CPP and PETCO2 in animal models. The frequency of POP closely matched the CPR heart rate. AUC and Amp of POP might be potential noninvasive quality monitoring markers for CPR.</AbstractText> |
10,230 | Atrial myocardial infarction: A tale of the forgotten chamber. | It has been almost a century since atrial infarction was first described, yet data describing its significance remain limited. To date, there are still no universally accepted criteria for the diagnosis of atrial infarction. Atherosclerosis is the leading cause of atrial infarction but it has also been described in cor pulmonale and pulmonary hypertension. Atrial infarction almost always occurs concomitantly with ventricular infarction. Its clinical presentation depends largely on the extent and site of ventricular involvement. Atrial infarction can present with supraventricular tachyarrhythmias. Electrocardiographic (ECG) criteria for diagnosing atrial infarction have been described but none have yet to be validated by prospective studies. Atrial ECG patterns include abnormal P-wave morphologies, PR-segment deviations, as well as transient rhythm abnormalities, including atrial fibrillation, atrial flutter, atrial tachycardia, wandering atrial pacemaker (WAP) and atrioventricular (AV) blocks. Complications of atrial infarction include thromboembolic events and cardiogenic shock. There are no specific additional recommendations in the management of myocardial infarction with suspected involvement of the atria. The primary goal remains coronary reperfusion and maintenance of, or conversion to, sinus rhythm. |
10,231 | [Early repolarization in ECG. Definition, prevalence and prognostic significance]. | Early repolarization defined as antero-lateral ST-segment elevation exists in 1-2 % of the general population and has been considered a benign ECG finding for decades. However, early repolarization, defined as infero-lateral J-waves, has in recent studies been associated with an increased - albeit low - risk of sudden and cardiovascular death. This ECG pattern is present in 3-13% of the general population. However, exercise training can induce all types of early repolarization, and the prevalence in the athletic population rises to 20-90%. There is large variability between sports (higher in endurance athletes) and also throughout the season (higher during times of peak fitness). In athletes, early repolarization, regardless of type, is considered benign. In asymptomatic non-athletes, the absolute risk is too low to use this ECG finding in clinical practice. In individuals with J-wave syndrome, on the other hand, ICD implantation should be strongly considered to prevent sudden cardiac death. |
10,232 | A Case of 5-Fluorouracil-Induced Cardiac Arrest. | Coronary artery vasospasm after administration of fluorouracil (5-FU) is a rare complication. Commonly presenting as chest pain during or shortly after 5-FU infusions, vasospasm can place patients at risk for ventricular dysrhythmia, myocardial ischemia, and infarction. Although not fully understood, any 5-FU cardiotoxicity seems to be multifactorial, and patients with coronary artery disease and renal dysfunction may be at particular risk.</AbstractText>A 46-year-old woman with no prior cardiovascular disease history presented with sudden-onset chest pain after initial administration of 5-FU continuous infusion therapy. The patient subsequently developed ventricular fibrillation arrest and underwent successful electrocardioversion. Coronary angiography was unremarkable for coronary stenosis or vasospasm. The presumed etiology was secondary to 5-FU cardiac toxicity. The patient was re-challenged with 5-FU therapy and developed repeat chest pain. The 5-FU was completely stopped and the patient's symptoms resolved, with no further dysrhythmic events 9 months after initial presentation. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Patients who develop chest pain during or after 5-FU infusion should warrant strong consideration for admission and continuous cardiac monitoring for potential ventricular dysrhythmias and cardiac ischemia.</AbstractText>Copyright © 2016 Elsevier Inc. All rights reserved.</CopyrightInformation> |
10,233 | [Mechanical cardiac-assist devices in ST segment elevation myocardial infarction]. | A 49-year-old woman was admitted for an anterior ST segment elevation myocardial infarction (STEMI). At hospital arrival, she presented with cardiogenic shock. An immediate coronary angiogram showed an occluded ostial left anterior descending artery. During percutaneous coronary intervention (PCI), ventricular fibrillation occurred requiring multiple electrical counter-shocks. The coronary artery was opened during cardiopulmonary resuscitation and two drug-eluting stents were implanted. At the end of the procedure, an Impella CP® mechanical cardiac-assist device was inserted. Rapid and marked improvement in the hemodynamic status was noted in the following days. The Impella CP® was withdrawn after five days and the patient was discharged two weeks later. Despite limited data, mechanical cardiac assistance is recommended in cardiogenic shock. Several devices are currently available; the choice of the system is based on the clinical presentation and the experience of each center. The Impella CP® is a microaxial pump which is inserted percutaneously and delivers up to 3.5L/min of continuous flow. In cardiogenic shock due to STEMI, this device allows temporary support while awaiting left ventricular recovery after primary PCI. |
10,234 | Kounis Syndrome Caused by Chronic Autoimmune Urticaria: A Case Report. | Coincidental occurrence of acute coronary syndrome with symptoms associated with an allergic reaction is called Kounis syndrome (KS). Although KS has been recognized for several years and has been reported in many documents, KS induced by chronic autoimmune urticaria (CAU), to the authors' knowledge, has not been reported.</AbstractText>The patient was a 31-year-old woman who suffered from chronic urticaria for nearly 3 years. Her urticaria became more serious 1 week before this visit and was accompanied by repeated attacks of cardiac symptoms. Autologous serum skin test and serum anti-high affinity immunoglobulin E receptor antibody test were positive for CAU. Her coronary artery pathological changes were confirmed by electrocardiogram (ECG), cardiac troponin T (cTnT) value, and angiocardiography. The patient was diagnosed with KS. After being treated with cetirizine, glucocorticoids, and azathioprine, the patient did not relapse during the first year of follow-up. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: When seeing a patient with intermittent exacerbations of chronic urticaria accompanied by repeated attacks of cardiac symptoms, emergency physicians should consider the diagnosis of KS. It is important to monitor changes in the ECG and cTnT value. Angiocardiography is necessary to eliminate myocardial infarction or unstable angina. Second-generation antihistamines and glucocorticoids are effective in the treatment of CAU and also alleviate coronary spasm. Another important consideration for the emergency physician is the fact that some first-generation antihistamines have the side effect of ventricular tachycardia or fibrillation, so it is better not to use these drugs to treat urticaria if KS is suspected.</AbstractText>Copyright © 2016 Elsevier Inc. All rights reserved.</CopyrightInformation> |
10,235 | ST-Segment Elevation and Fractionated Electrograms in Brugada Syndrome Patients Arise From the Same Structurally Abnormal Subepicardial RVOT Area but Have a Different Mechanism. | Brugada syndrome (BrS) is characterized by a typical ECG pattern. We aimed to determine the pathophysiologic basis of the ST-segment in the BrS-ECG with data from various epicardial and endocardial right ventricular activation mapping procedures in 6 BrS patients and in 5 non-BrS controls.</AbstractText>In 7 patients (2 BrS and 5 controls) with atrial fibrillation, an epicardial 8×6 electrode grid (interelectrode distance 1 mm) was placed epicardially on the right ventricular outflow tract (RVOT) before video-assisted thoracoscopic surgical pulmonary vein isolation. In 2 other BrS patients, endocardial, epicardial RV (CARTO), and body surface mapping was performed. In 2 additional BrS patients, we performed decremental preexcitation of the RVOT before endocardial RV mapping. During video-assisted thoracoscopic surgical pulmonary vein isolation and CARTO mapping, BrS patients (n=4) showed greater activation delay and more fractionated electrograms in the RVOT region than controls. Ajmaline administration increased the region with fractionated electrograms, as well as ST-segment elevation. Preexcitation of the RVOT (n=2) resulted in ECGs that supported the current-to-load mismatch hypothesis for ST-segment elevation. Body surface mapping showed that the area with ST-segment elevation anatomically correlated with the area of fractionated electrograms and activation delay at the RVOT epicardium.</AbstractText>ST-segment elevation and epicardial fractionation/conduction delay in BrS patients are most likely related to the same structural subepicardial abnormalities, but the mechanism is different. ST-segment elevation may be caused by current-to-load mismatch, whereas fractionated electrograms and conduction delay are expected to be caused by discontinuous conduction in the same area with abnormal myocardium.</AbstractText>© 2015 American Heart Association, Inc.</CopyrightInformation> |
10,236 | Optimizing clinical outcomes of transcatheter aortic valve implantation patients with comorbidities. | Transcatheter aortic valve implantation (TAVI) has revolutionized the management of high-risk or inoperable patients presenting with symptomatic severe aortic stenosis (AS). There are several factors to consider to optimize patient outcomes from TAVI. Before TAVI, patient selection is key and an understanding the effects of common comorbidities on outcomes after TAVI is critical. Some comorbidities share common risk factors with AS (e.g. coronary artery disease), others are directly or indirectly caused or exacerbated by severe AS (e.g. atrial fibrillation, pulmonary hypertension, mitral regurgitation, tricuspid regurgitation and right ventricular dysfunction), whereas others are not directly related to severe AS (e.g. chronic kidney disease and chronic lung disease). Choice of transcatheter heart valve prosthesis, vascular access route and mode of anesthesia are important considerations during TAVI. New onset conduction disturbances and arrhythmias remain a vexing issue after TAVI. The aim of the present review is to provide an overview of these issues. |
10,237 | Ventricular antitachycardia pacing therapy in patients with heart failure implanted with a cardiac resynchronization therapy defibrillator device: Efficacy, safety, and impact on mortality. | Cardiac resynchronization therapy defibrillator can terminate ventricular tachycardia (VT) and fast VT (FVT) via antitachycardia pacing (ATP).</AbstractText>We evaluated efficacy and safety of ATP, whether ATP induces ventricular arrhythmias after inappropriate ATP or atrial fibrillation (AF) after appropriate ATP, and whether ATP is associated with mortality.</AbstractText>A total of 1404 patients with a cardiac resynchronization therapy defibrillator were followed in a prospective multicenter observational research. All-cause mortality rates were estimated in patient subgroups in order to uncouple the trigger (VT/FVT or other rhythms causing inappropriate detections) from ATP therapy.</AbstractText>Over a median follow-up of 31 months, 2938 VT/FVT episodes were treated with ATP in 360 patients. The adjusted ATP success rate was 63% (95% confidence interval [CI] 57%-69%) on FVTs and 68% (95% CI 62%-74%) on VTs. Acceleration occurred in 55 (1.87%) and syncope in 4 (0.14%) of all ATP-treated episodes. In 14 true VT/FVT episodes in 5 patients, AF followed ATP therapy. In 4 episodes in 2 patients, VT followed ATP inappropriately applied during AF. Death rate per 100 patient-years was 5.6 (95% CI 4.3-7.5) in patients with appropriate ATP and 1.5 (95% CI 0.4-6.1) in patients with inappropriate ATP (P = .045).</AbstractText>ATP was effective in terminating VT/FVT episodes and displayed a good safety profile. ATP therapies by themselves did not increase death risk; prognosis was indeed better in patients without arrhythmic episodes, even if they received inappropriate ATP, than in patients with ATP on VT/FVT episodes. Adverse outcomes observed in patients receiving implantable cardioverter-defibrillator therapies are probably related to the arrhythmia itself, a marker of disease progression, rather than to adverse effects of ATP.</AbstractText>Copyright © 2016 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
10,238 | Incidence, Causes, and Predictors of Early (≤30 Days) and Late Unplanned Hospital Readmissions After Transcatheter Aortic Valve Replacement. | The aim of this study was to determine the incidence, causes, and predictors of unplanned hospital readmissions after transcatheter aortic valve replacement (TAVR).</AbstractText>Data regarding unplanned hospital readmissions after TAVR in a real-world all-comers population are scarce.</AbstractText>A total of 720 consecutive patients undergoing TAVR at 2 centers who survived the procedure, were included. Median follow-up was 23 months (interquartile range [IQR]: 12 to 39 months), available in 99.9% of the initial population. The occurrence, timing, and causes of hospital readmission within the first year post-TAVR were obtained in all cases. Early and late readmissions were defined as those occurring ≤30 days and >30 days to 1 year post-TAVR, respectively.</AbstractText>There were 506 unplanned readmissions in 316 patients (43.9%) within the first year post-TAVR (median time: 63 days; IQR: 19 to 158 days post-discharge). Of these, early readmission occurred in 105 patients (14.6%), and 118 patients (16.4%) had multiple (≥2) readmissions. Readmissions were due to noncardiac and cardiac causes in 59% and 41% of cases, respectively. Noncardiac readmissions included, in order of decreasing frequency, respiratory, infection, and bleeding events as the main causes, whereas heart failure and arrhythmias accounted for most cardiac readmissions. The predictors of early readmission were periprocedural major bleeding complications (p = 0.001), anemia (p = 0.019), lower left ventricular ejection fraction (p = 0.042), and the combined presence of antiplatelet and anticoagulation therapy at hospital discharge (p = 0.014). The predictors of late readmission were chronic obstructive pulmonary disease (p = 0.001), peripheral vascular disease (p = 0.023), chronic renal failure (p = 0.013), and atrial fibrillation (p = 0.012). Early readmission was an independent predictor of mortality during the follow-up period (hazard ratio: 1.56, 95% confidence interval: 1.02 to 2.39, p = 0.043).</AbstractText>The readmission burden after TAVR in an all-comers population was high. Nearly one-fifth of the patients were readmitted early after hospital discharge, increasing the risk of mortality at follow-up. Reasons for readmission were split between noncardiac and cardiac causes, with respiratory causes and heart failure as the main diagnoses in each group, respectively. Whereas early readmissions were mainly related to periprocedural bleeding events, most late readmissions were secondary to baseline patient comorbidities. These results underscore the importance of and provide the basis for implementing specific preventive measures to reduce readmission rates after TAVR.</AbstractText>Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
10,239 | Arrhythmogenic Phenotype in Dilated Cardiomyopathy: Natural History and Predictors of Life-Threatening Arrhythmias. | Patients with dilated cardiomyopathy (DCM) may present with ventricular arrhythmias early in the disease course, unrelated to the severity of left ventricular dysfunction. These patients may be classified as having an arrhythmogenic DCM (AR-DCM). We investigated the phenotype and natural history of patients with AR-DCM.</AbstractText>Two hundred eighty-five patients with a recent diagnosis of DCM (median duration of the disease 1 month, range 0 to 7 months) and who had Holter monitoring at baseline were comprehensively evaluated and followed for 107 months (range 29 to 170 months). AR-DCM was defined by the presence of ≥1 of the following: unexplained syncope, rapid nonsustained ventricular tachycardia (≥5 beats, ≥150 bpm), ≥1000 premature ventricular contractions/24 hours, and ≥50 ventricular couplets/24 hours, in the absence of overt heart failure. The primary end points were sudden cardiac death (SCD), sustained ventricular tachycardia (SVT), or ventricular fibrillation (VF). The secondary end points were death from congestive heart failure or heart transplantation. Of the 285 patients, 109 (38.2%) met criteria for AR-DCM phenotype. AR-DCM subjects had a higher incidence of SCD/SVT/VF compared with non-AR-DCM patients (30.3% vs 17.6%, P=0.022), with no difference in the secondary end points. A family history of SCD/SVT/VF and the AR-DCM phenotype were statistically significant and cumulative predictors of SCD/SVT/VF.</AbstractText>One-third of DCM patients may have an arrhythmogenic phenotype associated with increased risk of arrhythmias during follow-up. A family history of ventricular arrhythmias in DCM predicts a poor prognosis and increased risk of SCD.</AbstractText>© 2015 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.</CopyrightInformation> |
10,240 | An Effective and Reproducible Model of Ventricular Fibrillation in Crossbred Yorkshire Swine (Sus scrofa) for Use in Physiologic Research. | Transcutaneous electrical induction (TCEI) has been used to induce ventricular fibrillation (VF) in laboratory swine for physiologic and resuscitation research. Many studies do not describe the method of TCEI in detail, thus making replication by future investigators difficult. Here we describe a detailed method of electrically inducing VF that was used successfully in a prospective, experimental resuscitation study. Specifically, an electrical current was passed through the heart to induce VF in crossbred Yorkshire swine (n = 30); the current was generated by using two 22-gauge spinal needles, with one placed above and one below the heart, and three 9V batteries connected in series. VF developed in 28 of the 30 pigs (93%) within 10 s of beginning the procedure. In the remaining 2 swine, VF was induced successfully after medial redirection of the superior parasternal needle. The TCEI method is simple, reproducible, and cost-effective. TCEI may be especially valuable to researchers with limited access to funding, sophisticated equipment, or colleagues experienced in interventional cardiology techniques. The TCEI method might be most appropriate for pharmacologic studies requiring VF, VF resulting from the R-on-T phenomenon (as in prolonged QT syndrome), and VF arising from other ectopic or reentrant causes. However, the TCEI method does not accurately model the most common cause of VF, acute coronary occlusive disease. Researchers must consider the limitations of TCEI that may affect internal and external validity of collected data, when designing experiments using this model of VF. |
10,241 | Part 3: Adult Basic Life Support and Automated External Defibrillation: 2015 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations. | This review comprises the most extensive literature search and evidence evaluation to date on the most important international BLS interventions, diagnostics, and prognostic factors for cardiac arrest victims. It reemphasizes that the critical lifesaving steps of BLS are (1) prevention, (2) immediate recognition and activation of the emergency response system, (3) early high-quality CPR, and (4) rapid defibrillation for shockable rhythms. Highlights in prevention indicate the rational and judicious deployment of search-and-rescue operations in drowning victims and the importance of education on opioid-associated emergencies. Other 2015 highlights in recognition and activation include the critical role of dispatcher recognition and dispatch-assisted chest compressions, which has been demonstrated in multiple international jurisdictions with consistent improvements in cardiac arrest survival. Similar to the 2010 ILCOR BLS treatment recommendations, the importance of high quality was reemphasized across all measures of CPR quality: rate, depth, recoil, and minimal chest compression pauses, with a universal understanding that we all should be providing chest compressions to all victims of cardiac arrest. This review continued to focus on the interface of BLS sequencing and ensuring high-quality CPR with other important BLS interventions, such as ventilation and defibrillation. In addition, this consensus statement highlights the importance of EMS systems, which employ bundles of care focusing on providing high-quality chest compressions while extricating the patient from the scene to the next level of care. Highlights in defibrillation indicate the global importance of increasing the number of sites with public-access defibrillation programs. Whereas the 2010 ILCOR Consensus on Science provided important direction for the “what” in resuscitation (ie, what to do), the 2015 consensus has begun with the GRADE methodology to provide direction for the quality of resuscitation. We hope that resuscitation councils and other stakeholders will be able to translate this body of knowledge of international consensus statements to build their own effective resuscitation guidelines. |
10,242 | Lead Integrity Alert Is Useful for Assessment of Performance of Biotronik Linox Leads. | Medtronic's Lead Integrity Alert (LIA) software algorithm is useful for detecting abnormal parameters across various ICD-lead families. However, its utility in the assessment of the Biotronik Linox™ family of high-voltage (HV) leads is unknown.</AbstractText>We conducted a retrospective cohort study to assess the performance of the LIA algorithm to detect abnormalities and lead failure in Linox ICD-leads. All LIA-enabled Medtronic devices connected to an active Linox lead were included. The alerts were adjudicated by 2 blinded electrophysiologists and correlated with clinical data.</AbstractText>Between 2008 and 2012, data from 208 patients with 564 patient-years of follow-up were available for analysis. The median follow-up duration was 32 (IQR 21-41 months). Twenty-one LIA triggers were noted in 20 different patients. The median delay until a positive LIA was 32 months (IQR 21-41 months) postimplant with a 5-year lead survival free from LIA of 76%. Ninety-five percent (19/20) LIA alerts were true lead failures. The most common LIA triggers were short V-V intervals (85%) and nonsustained ventricular tachycardia (85%). Abrupt changes of the ICD-lead impedance occurred in 5/20 triggers. Inappropriate ICD-shocks were strongly associated with a positive LIA (30% vs. 7.4%; P = 0.006). Of the explanted Linox leads 53% had visible abnormalities. The sensitivity, specificity, and positive predictive value for lead failure in the presence of a LIA trigger were 87%, 99.5%, and 95.2%, respectively.</AbstractText>A positive LIA trigger in Biotronik Linox ICD-leads is highly predictive of lead failure. LIA is useful in ongoing surveillance of lead performance.</AbstractText>© 2015 Wiley Periodicals, Inc.</CopyrightInformation> |
10,243 | Arrhythmias in Adult Congenital Heart Disease: Diagnosis and Management. | Cardiac arrhythmias are a major source of morbidity and mortality in adults with CHD. A multidisciplinary approach in a center specializing in the care of ACHD is most likely to have the expertise needed provide this care. Knowledge of the underlying anatomy, mechanism of arrhythmia, and potential management strategies is critical, as well as access and expertise in the use of advanced imaging and ablative technologies. Future challenges in management include refining the underlying mechanism and putative ablation targets for catheter ablation of AF, an arrhythmia rapidly rising in prevalence in this population. |
10,244 | Risk factors predictive of atrial fibrillation after lung cancer surgery. | Postoperative atrial fibrillation (POAF), the most frequent arrhythmia after pulmonary resection, is a cause of both morbidity and mortality. Being able to predict the risk of POAF before surgery would help us evaluate the surgical risk and plan prophylaxis. We investigated the reported preoperative risk factors associated with the incidence of POAF and found that the recommended predictive factors were quite variable. Therefore, we evaluated the previously reported preoperative risk factors for POAF using our institutional data. We discuss our findings in this short review. Male gender, resected lung volume, brain natriuretic peptide (BNP), and left ventricular early transmitral velocity/mitral annular early diastolic velocity (E/e') calculated by echocardiography were suggested as independent predictors for POAF, but the predictive values of each individual parameter were not high. The lack of definitive predictors for POAF warrants further investigations by gathering the reported knowledge, to establish an effective preoperative examination strategy. |
10,245 | Comparison Between 30:1 and 30:2 Compression-to-ventilation Ratios for Cardiopulmonary Resuscitation: Are Two Ventilations Necessary? | Controversy is continuing over the need for ventilation and the optimal compression-ventilation (CV) ratio during cardiopulmonary resuscitation (CPR). The aim of this study was to comparatively elucidate the effect on hemodynamics and arterial oxygen saturation of a single ventilation relative to two consecutive ventilations during CPR in a dog model of cardiac arrest.</AbstractText>Twenty mongrel dogs were divided into two groups. After 3 minutes of ventricular fibrillation (VF), the single-ventilation group received CPR with a 30:1 CV ratio, and the two-ventilation group received CPR with a 30:2 CV ratio, all with room air for 7 minutes. Thereafter, continuous chest compressions and intermittent ventilation at rate of 10 per minute were followed for both groups for 10 minutes. Hemodynamic parameters, arterial blood gas profiles, and variables from CPR were compared at baseline and at 5, 10, 15, and 20 minutes after induction of VF.</AbstractText>Hemodynamic parameters including aortic systolic and diastolic pressures, right atrial systolic and diastolic pressures, coronary perfusion pressure, end-tidal carbon dioxide tension, and arterial blood gas profiles including arterial oxygen tension, arterial oxygen saturation, and arterial carbon dioxide tension were not different between two groups during CPR. In the 30:1 group, the period of compression interruption was shorter and chest compression fraction was higher than that in the 30:2 group (6 sec/min vs. 10.9 sec/min, p < 0.001; 90.0% vs. 81.8%, p < 0.001).</AbstractText>CPR with a 30:1 CV ratio, compared to CPR with a 30:2 CV ratio, results in comparable arterial oxygenation saturation and hemodynamics.</AbstractText>© 2015 by the Society for Academic Emergency Medicine.</CopyrightInformation> |
10,246 | Is the Preoperative Administration of Amiodarone or Metoprolol More Effective in Reducing Atrial Fibrillation: After Coronary Bypass Surgery? | This study examined the influence of preoperative administration of amiodarone and metoprolol in preventing postoperative atrial fibrillation (AF) after coronary artery bypass grafting (CABG) surgery.The study comprised 251 patients who underwent CABG surgery at our hospital between January 2012 and May 2014. The patients were randomly divided into 2 groups: amiodarone therapy group (n = 122 patients) and metoprolol therapy group (n = 129 patients).In the amiodarone group, the patients received amiodarone tablet orally 1 week before coronary bypass surgery and during the postoperative period. In the metoprolol group, the patients received metoprolol tablet orally 1 week before surgery and during the postoperative period. The AF development rate was retrospectively evaluated between the first 3 days and 4 weeks after surgery.AF developed in 14 patients in the amiodarone group and 16 patients in the metoprolol group 4 weeks after the operation (P = 0.612).No significant difference was observed between the groups in terms of intensive care unit and hospital stay. Furthermore, hospital charges were similar in both groups (P = 0.741).The results of the logistic regression analysis showed age, left ventricular ejection fraction, left atrial diameter, and aortic cross-clamping time to be predictors for postoperative AF.This study demonstrates that amiodarone and metoprolol have similar effects in prevention of AF after cardiac surgery. However, larger-scale studies need to be conducted to substantiate these findings. |
10,247 | Exercise-related sudden cardiac arrest in London: incidence, survival and bystander response. | The study aimed to (1) establish the incidence of exercise-related sudden cardiac arrest (SCA) in London, (2) investigate survival from exercise-related SCA and (3) examine factors related to survival.</AbstractText>This retrospective observational study examined 2 years' data from the London Ambulance Service (LAS) cardiac arrest registry for patients in whom resuscitation was attempted following an out-of-hospital cardiac arrest (OHCA), a cardiac cause was presumed and the arrest occurred during or within 1 h of exercise.</AbstractText>The incidence of exercise-related SCA in London was estimated to be 0.6 per 100 000 person-years which equated to 0.5% of all OHCA, and 1.5% of all OHCA with presumed cardiac aetiology and resuscitation attempted. The majority of cases were male and the incidence increased from age 40 years. Just under one-third of patients survived to hospital discharge. Survival in the Utstein comparator group (cases with presumed cardiac aetiology, resuscitation attempted, bystander witnessed and a presenting cardiac rhythm of ventricular fibrillation or tachycardia) was higher at 42%. Survival was significantly associated with initial cardiac rhythm (χ(2)=17.5, df=2, p<0.001) and bystander defibrillation (Fisher's exact test, p<0.05).</AbstractText>Incidence of exercise-related SCA in the general population in London is rare. Survival following exercise-related SCA was considerably higher than survival for all OHCA with presumed cardiac aetiology and resuscitation attempted attended by the LAS during the same period. The major limitation of the study is the likely under identification of cases of exercise-related SCA.</AbstractText> |
10,248 | Inappropriate combination of warfarin and aspirin. | A combination of warfarin and aspirin is associated with increased bleeding compared with warfarin monotherapy. The aim of the study was to investigate the incidence and appropriateness of the combination of warfarin and aspirin in patients with atrial fibrillation (AF) or mechanical heart valve (MHV).</AbstractText>This cross-sectional study included consecutive patients with AF or MHV on chronic warfarin therapy (>3 months) without acute coronary syndrome or have not undergone a revascularization procedure in the preceding year. Medical history, concomitant diseases, and treatment data were acquired through patient interviews and from hospital records.</AbstractText>Three hundred and sixty patients (213 with AF, 147 with MHV) were included. In those with AF, a significantly higher warfarin-aspirin combination was observed with concomitant vascular disease (38.8% vs. 14.6%), diabetes (36.6% vs. 16.3%), statin therapy (40% vs. 16.9%), left ventricular systolic dysfunction (33.3% vs. 17.5%) (p<0.05 for all). The use of combination therapy was similar between different CHADS-VASc scores. In patients with MHV, higher combination therapy was observed in males (41% vs. 26.7% in females; p=0.070), concomitant vascular disease (47.8% vs. 29.8%; p=0.091), and AF (56.3% vs. 29.8%; p=0.033). Independent predictors of warfarin-aspirin combination were concomitant vascular disease, diabetes, and (younger) age in patients with AF and were concomitant AF and male sex in patients with MHV. Interestingly, the incidence of combination therapy was found to increase with a higher HAS-BLED score in both patients with AF and MHV (p<0.001).</AbstractText>The combination of warfarin and aspirin was found to be prescribed to patients with AF mainly for the prevention of cardiovascular events, for which warfarin monotherapy usually suffices. On the other hand, co-treatment with aspirin appeared to be underused in patients with MHV.</AbstractText> |
10,249 | [Preoperative Risk Factors; Hypertension and Arrhythmias]. | Generally speaking, hypertension and arrhythmias are risk factors affecting anesthetic management and postoperative prognosis. However, the most recent ACC/AHA clinical guideline does not require the preoperative strict control of arterial pressure for patients with hypertension, since there has been not any definite evidence demonstrating that the preoperative control improves postoperative cardiovascular prognosis. On the other hand, the guideline recommends that preoperative management of patients with arrhythmias should be done according to the guideline for each arrhythmia. However, the guideline does not definitely mention the type of arrhythmias in which we should give priority to treatment of the arrhythmias over anesthesia for an elective operation. Presumably, the paucity of clinical studies to address this issue limits the definite recommendations. In patients with serious arrhythmias, such as ventricular tachycardia and atrial fibrillation with thrombus in the left atrium, preoperative clinical conference including anesthesiologist surgeons and cardiologists should be performed to decide the treatment plan for the patient Antihypertensive and antiarrhythmic drugs are frequently given in patients with hypertension or arrhythmias. These medicines as a general rule should be given until the morning of the operation day, although we do not have definite clinical evidence to support the advantage of the continuing. |
10,250 | The effects of proximal and distal routes of intraosseous epinephrine administration on short-term resuscitative outcome measures in an adult swine model of ventricular fibrillation: a randomized controlled study. | It is unknown if the anatomical distance of intraosseous (i.o.) epinephrine injection from the heart affects resuscitative outcome. The purpose of this study was to explore the relationships between the anatomical distance of i.o. epinephrine injection and measures of resuscitative outcome in an adult swine model of ventricular fibrillation (VF).</AbstractText>Thirty-two Yorkshire-cross swine (60-80 kg) were randomly assigned to four groups: humeral i.o. (HIO), tibial i.o. (TIO), i.v. with defibrillation and epinephrine, and i.v. control: with defibrillation but no epinephrine. Ventricular fibrillation was induced. Swine remained in VF for 4 minutes prior to mechanical chest compressions. After 6 minutes in VF, swine were defibrillated and epinephrine (0.01 mg/kg) administered by group assignment. Defibrillation was repeated every 2 minutes. Epinephrine was repeated every 4 minutes. Interventions continued until return of spontaneous circulation (ROSC) or 26 post-arrest minutes elapsed. Swine achieving ROSC were observed for 30 minutes post-ROSC.</AbstractText>There were no significant differences between the HIO, TIO, and i.v. groups relative to the occurrence of ROSC (P > .05 in all cases), 30-minute post-ROSC survival (P > .05 in all cases), and time to ROSC (P = .43). There were significant differences between the HIO, TIO, and i.v. groups compared to the control group relative to the occurrence of ROSC (P = .02, .01, and .007 respectively), and 30 minute post-ROSC survival (P = .05, .03, and .007, respectively).</AbstractText>The anatomical distance of i.o. epinephrine injection from the heart did not affect short-term measures of resuscitative outcome in an adult swine model of VF including the occurrence of ROSC, 30 minute post-ROSC survival, and time to ROSC. Rapidly administered epinephrine, irrespective of route of administration, increased the chance ROSC and survival to 30 minutes post-ROSC would occur in this study.</AbstractText>Published by Elsevier Inc.</CopyrightInformation> |
10,251 | First clinical trial of specific IKACh blocker shows no reduction in atrial fibrillation burden in patients with paroxysmal atrial fibrillation: pacemaker assessment of BMS 914392 in patients with paroxysmal atrial fibrillation. | To assess the efficacy of BMS 914392 on atrial fibrillation (AF) burden reduction in 20 patients with pacemakers and paroxysmal atrial fibrillation (PAF). BMS 914392 is a potent, selective, oral inhibitor of the IKACh current and has been shown to suppress AF, whilst having no effect on the ventricular refractory period. This is the first efficacy study of BMS 914392 in patients with PAF.</AbstractText>The study was a four-way, crossover, double-blind design. A total of 20 patients with PAF and dual-chamber pacemakers were recruited. The pacemakers allowed beat-to-beat monitoring. Anti-arrhythmic drugs were withdrawn. Patients received low-dose (10 mg OD), medium-dose (10 mg TDS), and high-dose (20 mg TDS) BMS 914392 or placebo for 3 weeks before being crossed to the next phase. Patients underwent a washout period, four treatment phases and a final washout phase. Atrial fibrillation burden was downloaded from their pacemakers at the end of each study phase. BMS 914392 did not reduce AF burden when compared with placebo (10 mg OD P = 0.56, 10 mg TDS P = 0.22, 20 mg TDS P = 0.23). Heart rate and corrected QT (QTc) were not affected by BMS 914392. Adverse event (AE) rates did not differ from placebo in any of the treatment groups, with no serious AEs recorded.</AbstractText>BMS 914932 has not been shown to reduce AF burden in patients with PAF and pacemakers using beat-to-beat pacemaker monitoring throughout the study. BMS 914392 was well tolerated and did not affect QTc or reduce heart rate.</AbstractText>Clinicaltrials.gov: NCT01356914.</AbstractText>Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.</CopyrightInformation> |
10,252 | Fluid dynamics of heart valves during atrial fibrillation: a lumped parameter-based approach. | Atrial fibrillation (AF) consequences on the heart valve dynamics are usually studied along with a valvular disfunction or disease, since in medical monitoring, the two pathologies are often concomitant. Aim of the present work is to study, through a stochastic lumped-parameter approach, the basic fluid dynamics variations of heart valves, when only paroxysmal AF is present with respect to the normal sinus rhythm in absence of any valvular pathology. Among the most common parameters interpreting the valvular function, the most useful turns out to be the regurgitant volume. During AF, both atrial valves do not seem to worsen their performance, while the ventricular efficiency is remarkably reduced. |
10,253 | Ranolazine in Cardiac Arrhythmia. | Ranolazine utilization in the management of refractory angina has been established by multiple randomized clinical studies. However, there is growing evidence showing an evolving role in the field of cardiac arrhythmias. Multiple experimental and clinical studies have evaluated the role of ranolazine in prevention and management of atrial fibrillation, with ongoing studies on its role in ventricular arrhythmias. In this review, we will discuss the pharmacological, experimental, and clinical evidence behind ranolazine use in the management of various cardiac arrhythmias. |
10,254 | The positive frequency-dependent electrophysiological effects of the IKur inhibitor XEN-D0103 are desirable for the treatment of atrial fibrillation. | Selective inhibitors of Kv1.5 channels are being developed for the treatment of atrial fibrillation (AF).</AbstractText>The purpose of this study was to investigate the effects of the highly selective Kv1.5 inhibitor XEN-D0103 on human atrial action potentials (APs) at high excitation rates and to assess safety.</AbstractText>Intracellular APs (stimulation rates 1-5 Hz) were measured in right atrial trabeculae from patients in sinus rhythm (SR), chronic AF (cAF; AF of >6 months duration), and paroxysmal AF (pAF). The safety and tolerability of XEN-D0103 were tested in a double-blind, randomized, placebo-controlled phase 1 study.</AbstractText>Depending on its concentration, XEN-D0103 elevated the plateau potential. At 1 Hz, XEN-D0103 (3 µM) shortened action potential duration at 90% repolarization (APD90) and effective refractory period (ERP) in SR preparations, but prolonged these parameters in cAF preparations. In SR and pAF preparations, the shortening effects on APD90 and ERP turned into prolongation at high rates. In cAF trabeculae, XEN-D0103 prolonged APD90 and ERP at 2 and 3 Hz. At high rates, more SR and pAF preparations failed to capture excitation in the presence of the drug than in its absence. XEN-D0103 (10 µM) did not significantly affect human ventricular APs. Even with plasma concentrations reaching 7000 ng/mL, XEN-D0103 did not increase ∆∆QTcF (QT interval corrected by the Fridericia formula) in the analysis of electrocardiograms of healthy volunteers, and no subjects receiving an active treatment had a QT or QTcF interval >450 ms, or increase in QTcF from baseline >30 ms.</AbstractText>APD prolongation and suppression of APs by XEN-D0103 at high stimulation rates in SR and pAF tissue, but not cAF, could be of therapeutic benefit for reducing AF burden. This concept needs to be confirmed in clinical trials.</AbstractText>Copyright © 2016 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
10,255 | Discharge risk scoring method for predicting mortality in hospitalized chronic heart failure patients with severe systolic dysfunction. | Prognostic risk stratification in heart failure is crucial to guide clinical decision-making.The aim of our study was to develop a prognostic discharge risk score model to predict all-cause mortality for chronic heart failure patients with multiple co-morbidities and severe systolic dysfunction.</AbstractText>A multivariable logistic regression model was developed with the use of data on clinical, laboratory, imaging and therapeutic findings of 630 patients with advanced systolic heart failure. A risk score model was developed based on multiplying the beta-coefficient number of each variable in the multivariable model. The model performance was evaluated by concordance index and internally validated by the bootstrapping method. 313 patients (49.7%) of the cohort died during a median follow-up duration of 54 months. Median age was 66 years, 37% were female, 26% had atrial fibrillation and 40% had diabetes mellitus. The mean left ventricular ejection fraction (EF) was 25 +/- 10% and 264 patients (42%) had left ventricular EF < or = 20%. Independent predictors of mortality were older than 70 years, orthopnoea, previous hospitalisations, lack of renin-angiotensin system inhibitor therapy at discharge, hyperuricaemia (>7 mg/dl) and haemoglobin level (<10 g/dL). Discharge risk score identified low-, intermediate- and high-risk individuals with 18%, 40% and 52% mortality rates, respectively. The risk score had a discrimination ability with a concordance index of 0.70.</AbstractText>In a large heart failure cohort, including patients with severe systolic dysfunction and having multiple comorbidities, a simple discharge risk score with non-invasive and easy-to-obtain variables during hospital admission represents a valuable tool for risk assessment.</AbstractText> |
10,256 | Early Coronary Angiography and Survival After Out-of-Hospital Cardiac Arrest. | Although out-of-hospital cardiac arrest is common because of acute myocardial infarction, it is unknown whether early coronary angiography is associated with improved survival in these patients.</AbstractText>Using data from the Cardiac Arrest Registry to Enhance Survival (CARES), we identified 4029 adult patients admitted to 374 hospitals after successful resuscitation from out-of-hospital cardiac arrest because of ventricular fibrillation, pulseless ventricular tachycardia, or unknown shockable rhythm between January 2010 and December 2013. Early coronary angiography (occurring within one calendar day of cardiac arrest) was performed in 1953 (48.5%) patients, of whom 1253 (64.2%) received coronary revascularization. Patients who underwent early coronary angiography were younger (59.9 versus 62.0 years); more likely to be men (78.1% versus 64.3%), have a witnessed arrest (84.6% versus 77.4%), and have ST-segment-elevation myocardial infarction (32.7% versus 7.9%); and less likely to have known cardiovascular disease (22.8% versus 35.0%), diabetes mellitus (11.0% versus 17.0%), and renal disease (1.8% versus 5.8%; P<0.01 for all comparisons). In analysis of 1312 propensity score-matched pairs, early coronary angiography was associated with higher odds of survival to discharge (odds ratio 1.52 [95% confidence interval 1.28-1.80]; P<0.0001) and survival with favorable neurological outcome (odds ratio 1.47 [95% confidence interval 1.25-1.71]; P<0.0001). Further adjustment for coronary revascularization in our models significantly attenuated both odds ratios, suggesting that revascularization was a key mediator of the survival benefit.</AbstractText>Among initial survivors of out-of-hospital cardiac arrest caused by VF or pulseless VT, we found early coronary angiography was associated with higher odds of survival to discharge and favorable neurological outcome.</AbstractText>© 2015 American Heart Association, Inc.</CopyrightInformation> |
10,257 | Predicting the Presence of an Acute Coronary Lesion Among Patients Resuscitated From Cardiac Arrest. | A mechanism to stratify patients resuscitated from a cardiac arrest according to the likelihood of an acute coronary lesion would have significant utility. We thus sought to develop and validate a risk prediction model for the presence of an acute coronary lesion among patients resuscitated from an arrest.</AbstractText>All subjects undergoing coronary angiography after resuscitation from a cardiac arrest were identified in an ongoing institutional registry from 2009 to 2014. Backwards stepwise selection of candidate covariates was used to create a logistic regression model for the presence of an angiographic culprit lesion and internally validated with bootstrapping. A clinical point score was generated and its prognostic abilities compared with contemporary measures. Among 247 subjects undergoing coronary angiography after resuscitation from a cardiac arrest, 130 (52%) had an acute lesion in a coronary artery. A multivariable model-including angina, congestive heart failure symptoms, shockable arrest rhythm (ventricular fibrillation/ventricular tachycardia), and ST-elevations-had excellent discrimination (optimism corrected C-Statistic, 0.88) and calibration (Hosmer-Lemeshow P=0.540) for an acute coronary lesion. Compared with electrocardiographic findings alone, a point score based on this model more accurately predicted the presence of an acute lesion among patients resuscitated from a cardiac arrest (integrated discrimination improvement, 0.10; 95% confidence interval, 0.04-0.19; P<0.001).</AbstractText>Patients with a cardiac arrest can be risk stratified for the presence of an acute coronary lesion using 4 easily measured variables. This simple risk score may be used to improve patient selection for emergent coronary angiography among resuscitated patients.</AbstractText>© 2015 American Heart Association, Inc.</CopyrightInformation> |
10,258 | Survival After Ventricular Fibrillation Cardiac Arrest in the Sao Paulo Metropolitan Subway System: First Successful Targeted Automated External Defibrillator (AED) Program in Latin America. | Targeted automated external defibrillator (AED) programs have improved survival rates among patients who have an out-of-hospital cardiac arrest (OHCA) in US airports, as well as European and Japanese railways. The Sao Paulo (Brazil) Metro subway carries 4.5 million people per day. A targeted AED program was begun in the Sao Paulo Metro with the objective to improve survival from cardiac arrest.</AbstractText>A prospective, longitudinal, observational study of all cardiac arrests in the Sao Paulo Metro was performed from September 2006 through November 2012. This study focused on cardiac arrest by ventricular arrhythmias, and the primary endpoint was survival to hospital discharge with minimal neurological impairment. A total of 62 patients had an initial cardiac rhythm of ventricular fibrillation. Because no data on cardiac arrest treatment or outcomes existed before beginning this project, the first 16 months of the implementation was used as the initial experience and compared with the subsequent 5 years of full operation. Return of spontaneous circulation was not different between the initial 16 months and the subsequent 5 years (6 of 8 [75%] vs. 39 of 54 [72%]; P=0.88). However, survival to discharge was significantly different once the full program was instituted (0 of 8 vs. 23 of 54 [43%]; P=0.001).</AbstractText>Implementation of a targeted AED program in the Sao Paulo Metro subway system saved lives. A short interval between arrest and defibrillation was key for good long-term, neurologically intact survival. These results support strategic expansion of targeted AED programs in other large Latin American cities.</AbstractText>© 2015 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.</CopyrightInformation> |
10,259 | Etiology and Programming Effects on Shock Efficacy in ICD Recipients. | We sought to assess the efficacy of high-energy shocks to restore rhythm and predictors of success in patients with sustained ventricular arrhythmias and implantable cardioverter defibrillator (ICD).</AbstractText>Data from 162 patients included in the UMBRELLA study that experienced one or more episodes of ventricular tachycardia (VT) for which ICD shocks of at least 30 Joules were delivered (appropriate high-energy shocks) were analyzed. In total, 456 ventricular arrhythmia episodes were registered. Forty four episodes (9.6%) from 39 patients (24%) had at least one ineffective high-energy shock delivered. Hypertrophic cardiomyopathy was more frequent among patients with unsuccessful shocks (10.3% vs 2.4%). Patients with ineffective shocks had higher proportion of sustained monomorphic ventricular arrhythmias (86.4%; the other 13.6% were sustained polymorphic and ventricular fibrillation [VF]) compared with patients with all their shocks effective (62.9%, P = 0.02). No statistical differences were found between groups in time from detection to the high-energy shock delivery, in tachycardia cycle length, or in antitachycardia pacing, but patients with ineffective high-energy shocks had higher proportion of previously ineffective low-energy shock (9.1% vs 0.5%, P = 0.01).</AbstractText>We found a substantial rate of ineffective high-energy shocks for the treatment of VT or VF in patients with ICD. High-energy shock efficacy seems to be reduced by hypertrophic cardiomyopathy and by the administration of previous low-energy shocks.</AbstractText>© 2015 Wiley Periodicals, Inc.</CopyrightInformation> |
10,260 | The HVAD Left Ventricular Assist Device: Risk Factors for Neurological Events and Risk Mitigation Strategies. | The purpose of this study was to determine the risk factors for ischemic in hemorrhage cerebrovascular events in patients supported by the HeartWare ventricular assist device (HVAD).</AbstractText>Patients supported with left ventricular assist devices are at risk for both ischemic and hemorrhagic cerebrovascular events.</AbstractText>Patients undergoing implantation with a HVAD as part of the bridge-to-transplant trial and subsequent continued access protocol were included. Neurological events (ischemic cerebrovascular accidents [ICVAs] and hemorrhagic cerebrovascular accidents [HCVAs]) were assessed, and the risk factors for these events were evaluated in a multivariable model.</AbstractText>A total of 382 patients were included: 140 bridge-to-transplant patients from the ADVANCE (Evaluation of the HeartWare Left Ventricular Assist Device for the Treatment of Advanced Heart Failure) clinical trial and 242 patients from the continued access protocol. Patients had a mean age of 53.2 years; 71.2% were male, and 68.1% were white. Thirty-eight percent had ischemic heart disease, and the mean duration of support was 422.7 days. The overall prevalence of ICVA was 6.8% (26 of 382); for HCVA, it was 8.4% (32 of 382). Pump design modifications and a protocol-driven change in the antiplatelet therapy reduced the prevalence of ICVA from 6.3% (17 of 272) to 2.7% (3 of 110; p = 0.21) but had a negligible effect on the prevalence of HVCA (8.8% [24 of 272] vs. 6.4% [7 of 110]; p = 0.69). Multivariable predictors of ICVA were aspirin ≤81 mg and atrial fibrillation; predictors of HCVA were mean arterial pressure >90 mm Hg, aspirin ≤81 mg, and an international normalized ratio >3.0. Eight of the 30 participating sites had established improved blood pressure management (IBPM) protocols. Although the prevalence of ICVA for those with and without IBPM protocols was similar (5.3% [6 of 114] vs. 5.2% [14 of 268]; p = 0.99), those with IBPM protocols had a significantly lower prevalence of HCVA (1.8% [2 of 114] vs. 10.8% [29 of 268]; p = 0.0078).</AbstractText>Anticoagulation, antiplatelet therapy, and blood pressure management affected the prevalence of cerebrovascular events after implantation of the HVAD. Attention to these clinical parameters can have a substantial impact on the occurrence of serious neurological events. (Evaluation of the HeartWare Left Ventricular Assist Device for the Treatment of Advanced Heart Failure [ADVANCE]; NCT00751972).</AbstractText>Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
10,261 | Arrhythmia-Induced Cardiomyopathies: Mechanisms, Recognition, and Management. | Arrhythmia-induced cardiomyopathy (AIC) is a potentially reversible condition in which left ventricular dysfunction is induced or mediated by atrial or ventricular arrhythmias. Cellular and extracellular changes in response to the culprit arrhythmia have been identified, but specific pathophysiological mechanisms remain unclear. Early recognition of AIC and prompt treatment of the culprit arrhythmia using pharmacological or ablative techniques result in symptom resolution and recovery of ventricular function. Although cardiomyopathy in response to an arrhythmia may take months to years to develop, recurrent arrhythmia can result in rapid decline in ventricular function with development of heart failure, suggesting residual ultrastructural abnormalities. Reports of sudden death in patients with normalized left ventricular ejection fraction cast doubt on the complete reversibility of this condition. Several aspects of AIC, including specific pathophysiological mechanisms, predisposing factors, optimal therapeutic strategies to prevent ultrastructural changes, and long-term risk of sudden death remain unresolved and need further research. |
10,262 | Clinical and Echocardiographic Factors Affecting Tricuspid Regurgitation Severity in the Patients with Lone Atrial Fibrillation. | Atrial fibrillation (AF) can be a risk factor for development of significant tricuspid regurgitation (TR). We investigated which clinical and echocardiographic parameters were related to severity of functional TR in patients with lone AF.</AbstractText>A total of 89 patients with lone AF were enrolled (75 ± 11 years; 48% male): 13 patients with severe TR, 36 patients with moderate TR, and 40 consecutive patients with less than mild TR. Clinical parameters and echocardiographic measurements including right ventricular (RV) remodeling and function were evaluated.</AbstractText>Patients with more severe TR were older and had more frequently persistent AF (each p < 0.001). TR severity was related to right atrial area and tricuspid annular systolic diameter (all p < 0.001). The patients with moderate or severe TR had larger left atrial (LA) volume and increased systolic pulmonary artery pressure (SPAP) than the patients with mild TR (p = 0.04 for LA volume; p < 0.001 for SPAP). RV remodeling represented by enlarged RV area and increased tenting height was more prominent in severe TR than mild or moderate TR (all p < 0.001). Multivariate analysis showed type of AF, LA volume, tricuspid annular diameter and tenting height remained as a significant determinants of severe TR. In addition, tenting height was independently associated with the presence of severe TR (p = 0.04).</AbstractText>In patients with lone AF, TR was related to type of AF, LA volume, tricuspid annular diameter and RV remodeling. Especially, tricuspid valvular tethering seemed to be independently associated with development of severe functional TR.</AbstractText> |
10,263 | How are arrhythmias detected by implanted cardiac devices managed in Europe? Results of the European Heart Rhythm Association Survey. | The management of arrhythmias detected by implantable cardiac devices can be challenging. There are no formal international guidelines to inform decision-making. The purpose of this European Heart Rhythm Association (EHRA) survey was to assess the management of various clinical scenarios among members of the EHRA electrophysiology research network. There were 49 responses to the questionnaire. The survey responses were mainly (81%) from medium-high volume device implanting centres, performing more than 200 total device implants per year. Clinical scenarios were described focusing on four key areas: the implantation of pacemakers for bradyarrhythmia detected on an implantable loop recorder (ILR), the management of patients with ventricular arrhythmia detected by an ILR or pacemaker, the management of atrial fibrillation in patients with pacemakers and cardiac resynchronization therapy devices and the management of ventricular tachycardia in patients with implantable cardioverter-defibrillators. |
10,264 | Effect of caffeine on ventricular arrhythmia: a systematic review and meta-analysis of experimental and clinical studies. | The relationship between caffeine consumption and the occurrence of arrhythmias remains controversial. Despite this lack of scientific evidence, counselling to reduce caffeine consumption is still widely advised in clinical practice. We conducted a systematical review and meta-analysis of interventional studies of the caffeine effects on ventricular arrhythmias.</AbstractText>The search was performed on Pubmed, Embase, and Cochrane database, and terms related to coffee, caffeine, and cardiac arrhythmias were used. Methodological quality was assessed based on The Cochrane Collaboration recommendations and the ARRIVE guidelines. There were 2016 citations retrieved on the initial research. After full-text assessment, seven human and two animal studies were included in the meta-analysis. In animal studies, the main outcome reported was the ventricular fibrillation threshold. We observed a significant mean difference of -2.15 mA (95% CI -3.43 to -0.87; I(2) 0.0%, P for heterogeneity = 0.37). The main outcome evaluated in human studies was the rate of ventricular premature beats (VPBs). The overall relative risk for occurrence of VPBs in 24 h attributed to caffeine exposure was 1.00 (95% CI 0.94-1.06; I(2) 13.5%, P for heterogeneity = 0.32). Sensitivity analysis for caffeine dose, different designs, and subject profile was performed and no major differences were observed.</AbstractText>Our meta-analysis demonstrates that data from human interventional studies do not show a significant effect of caffeine consumption on the occurrence of VBPs. The effects observed in animal studies are most probably the result of very high caffeine doses that are not regularly consumed in a daily basis by humans.</AbstractText>Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.</CopyrightInformation> |
10,265 | The risk of atrial fibrillation during right ventricular pacing. | Right ventricular pacing adversely affects left atrial (LA) structure and function that may trigger atrial fibrillation (AF). This study compares the occurrence of persistent/permanent AF during long-term Hisian area (HA), right ventricular septal (RVS), and right ventricular apex (RVA) pacing in patients with complete/advanced atrioventricular block (AVB).</AbstractText>We collected retrospective data from 477 consecutive patients who underwent pacemaker implantation for complete/advanced AVB. Ventricular pacing leads were located in the HA, RVS, and RVA in 148, 140, and 189 patients, respectively. The occurrence of persistent/permanent AF was observed in 114 (23.9%) patients (follow-up 58.5 ± 26.5 months). Hisian area groups presented a lower rate of AF occurrence (16.9%) compared with RVS and RVA groups (25.7 and 28.0%, respectively), P = 0.049. Cox's proportional hazard model was used to estimate HR. The risk of persistent/permanent AF was significantly lower in the patients paced from HA compared with those paced from RVA, HR = 0.28 (95% CI 0.16-0.48, P = 0.0001). The RVS and RVA pacing groups showed a similar AF risk: HR 1.04 (95% CI 0.66-1.64, P = 0.856). Other independent predictors of persistent/permanent AF occurrence included previous (before device implantation) paroxysmal AF (HR = 4.08; 95% CI 3.15-7.31, P = 0.0001), LA diameter, and age, whereas baseline bundle-branch block was associated with a lower risk of AF occurrence (HR = 0.56; 95% CI 0.35-0.81, P = 0.003).</AbstractText>HA pacing compared with RVA or RVS pacing seems to be associated with a lower risk of persistent/permanent AF occurrence. The risk of persistent/permanent AF was similar in the RVA vs. RVS groups.</AbstractText>Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.</CopyrightInformation> |
10,266 | Neuromodulation for cardiac arrhythmia. | The autonomic nervous system is known to play a significant role in the genesis and maintenance of arrhythmias. Neuromodulation, mostly designed to increase the parasympathetic tone and suppress the sympathetic tone, has become an emerging therapeutic strategy for the treatment of arrhythmias. Emerging therapeutic approaches include cervical vagal stimulation, transcutaneous auricular vagal stimulation, baroreceptor activation therapy spinal cord stimulation, ganglionated plexi ablation, renal sympathetic denervation, and left cardiac sympathetic denervation. |
10,267 | Perioperative atrial fibrillation: a systematic review of evolving therapeutic options in pharmacologic and procedural management. | Given the high incidence of atrial fibrillation (AF) in the surgical population and the associated morbidity, physicians managing these complicated patients in the perioperative period need to be aware of the new and emerging trends in its therapy. The cornerstones of AF management have always been rate/rhythm control as well as anticoagulation. Restoration of sinus rhythm remains the fundamental philosophy as it maintains the atrial contribution to cardiac output and improves ventricular function. The recent years have seen a dramatic increase in the number of randomized AF trials that have made significant advances to our understanding of both pharmacologic and procedural management, from the introduction of the new generation of oral anticoagulants (NOAC's) to catheter approaches for AF ablation. This paper will summarize the newest data that will affect the perioperative management of these patients. |
10,268 | Sex Differences in Patients With Acute Decompensated Heart Failure: Insights From the Heart Function Assessment Registry Trial in Saudi Arabia. | We assessed sex-specific differences in clinical features and outcomes of patients with acute heart failure (AHF). The Heart function Assessment Registry Trial in Saudi Arabia (HEARTS), a prospective registry, enrolled 2609 patients with AHF (34.2% women) between 2009 and 2010. Women were older and more likely to have risk factors for atherosclerosis, history of heart failure (HF), and rheumatic heart and valve disease. Ischemic heart disease was the prime cause for HF in men and women but more so in men (P < .001). Women had higher rates of hypertensive heart disease and primary valve disease (P < .001, for both comparisons). Men were more likely to have severe left ventricular systolic dysfunction. On discharge, a higher use of angiotensin-converting enzyme inhibitors, β-blockers, and aldosterone inhibitors was observed in men (P < .001 for all comparisons). Apart from higher atrial fibrillation in women and higher ventricular arrhythmias in men, no differences were observed in hospital outcomes. The overall survival did not differ between men and women (hazard ratio: 1.0, 95% confidence interval: 0.8-1.2, P = .981). Men and women with AHF differ significantly in baseline clinical characteristics and management but not in adverse outcomes. |
10,269 | Arrhythmogenic Risk Assessment Following Four-Week Pretreatment With Nicotine and Black Tea in Rat. | There is the controversy concerning the main component of tobacco, which is responsible for its arrhythmogenesis. In addition, there is the lack of adequate information about the influence of combination of black tea and nicotine on heart rhythm.</AbstractText>This study aimed to examine whether pretreatment with black tea and nicotine could modulate the susceptibility to lethal ventricular arrhythmias.</AbstractText>Animals were randomized to control, black tea, nicotine, and black tea plus nicotine groups. Test groups were treated with black tea brewed (orally) and nicotine (2 mg/kg, subcutaneous), alone and in combination for four weeks. On day 29, aconitine was infused intravenously for induction of cardiac arrhythmia.</AbstractText>In comparison with the control group, each of tea and nicotine significantly decreased the duration of the ventricular tachycardia (VT) plus ventricular fibrillation (VF) and the score of arrhythmia severity (P < 0.05 and P < 0.01, respectively,). The latency for the first VT event was significantly longer in the all test groups, but VF latency was significant only in tea and nicotine groups compared with control group (P < 0.05 and P < 0.01, respectively).Threshold dose of aconitine for inducing VT and VF increased in all test groups, but only VT showed a significant difference in comparison to the control group (P < 0.001).</AbstractText>The findings suggest that sub-chronic consumption of nicotine or black tea alone with appropriate doses could potentially be antiarrhythmic and its combination regimen does not increase the risk of fatal ventricular arrhythmias during four-week consumption period in rats.</AbstractText> |
10,270 | Atrial Fibrillation Due to Over The Counter Stimulant Drugs in A Young Adult. | The usage of over the counter stimulant drugs and energy drinks is increasing on a day to day basis for various purposes including work, sports and leisure among individuals in all age groups. Multiple formulations are available in the market including pills, liquid capsules and drinks in various flavours. Many of them contain excessively high doses of caffeine along with a variety of stimulant compounds that have multiple effects in different parts of the human body. The consumption of such high amounts of caffeine itself has shown to have caused cardiac arrhythmias in healthy individuals and when it is mixed with a number of stimulant compounds can be associated with a number of adverse effects in the human body. However, the awareness of such life threatening complications associated with these energy drinks does not exist among people who consume it on a day to day basis. We report a case of 25-year-old Caucasian male with no significant past medical history for cardiac diseases, no risk factors for atrial fibrillation, non smoker, occasional alcohol drinker who presents with new onset atrial fibrillation with rapid ventricular response due to the consumption of over the counter stimulant energy capsule which had high doses of caffeine. |
10,271 | Mechanical circulatory support devices and transcatheter aortic valve implantation (from the National Inpatient Sample). | High-risk surgical patients undergoing transcatheter aortic valve implantation (TAVI) represent an emerging population, which may benefit from short-term use of mechanical circulatory support (MCS) devices. The aim of this study was to determine the practice and inhospital outcomes of MCS utilization in patients undergoing TAVI. We analyzed data from Nationwide Inpatient Sample (2011 and 2012) using the International Classification of Diseases, Ninth Revision, Clinical Modification procedure codes. A total of 1,794 TAVI procedures (375 hospitals in the United States) were identified of which 190 (10.6%) used an MCS device (MCS group) and 1,604 (89.4%) did not (non-MCS group). The use of MCS devices with TAVI was associated with significant increase in the inhospital mortality (14.9% vs 3.5%, p <0.01). The mean length (11.8 ± 0.8 vs 8.1 ± 0.2 days, p <0.01) and cost ($68,997 ± 3,656 vs $55,878 ± 653, p = 0.03) of hospitalization were also significantly greater in the MCS group. Ventricular fibrillation arrest, transapical access for TAVI, and cardiogenic shock were the most significant predictors of MCS use during TAVI. In the multivariate model, use of any MCS device was found to be an independent predictor of increased mortality (odds ratio 3.5, 95% confidence interval 2.6 to 4.6, p <0.0001) and complications (odds ratio 3.3, 95% confidence interval 2.8 to 3.9, p <0.0001). The propensity score-matched analysis also showed a similar result. In conclusion, the unacceptably high rates of mortality and complications coupled with a significant increase in the length and cost of hospitalization should raise concerns about utility of MCS devices during TAVI in this prohibitive surgical risk population. |
10,272 | Dabigatran for left ventricular thrombus. | Male patient in dilated phase of hypertrophic cardiomyopathy had multiple hospitalizations during the past 2 years either due to congestive heart failure, stroke, scar epilepsy, or atrial fibrillation and ventricular tachycardia. Medication included evidence based therapy for heart failure, cordarone and warfarin. Anticoagulation had to be discontinued due to marked fluctuations in INR. Transthoracic Echocardiography (TTE) revealed a mobile mass in the left ventricle. He was treated with Dabigatran 110mg twice a day for 4 months without any bleeding or embolic episode and complete resolution of thrombus. Dabigatran is a reversible direct thrombin inhibitor and currently approved for the prevention of thromboembolic episodes in non-valvar atrial fibrillation. This case demonstrates possible thrombolytic properties of dabigatran in resolution of left ventricular thrombus. |
10,273 | The impact of 6 weeks of atrial fibrillation on left atrial and ventricular structure and function. | The impact of prolonged episodes of atrial fibrillation on atrial and ventricular function has been incompletely characterized. The purpose of this study was to investigate the influence of atrial fibrillation on left atrial and ventricular function in a rapid paced porcine model of atrial fibrillation.</AbstractText>A control group of pigs (group 1, n = 8) underwent left atrial and left ventricular conductance catheter studies and fibrosis analysis. A second group (group 2, n = 8) received a baseline cardiac magnetic resonance imaging to characterize left atrial and left ventricular function. The atria were rapidly paced into atrial fibrillation for 6 weeks followed by cardioversion and cardiac magnetic resonance imaging.</AbstractText>After 6 weeks of atrial fibrillation, left atrial contractility defined by atrial end-systolic pressure-volume relationship slope was significantly lower in group 2 than in group 1 (1.1 ± 0.5 vs 1.7 ± 1.0; P = .041), whereas compliance from the end-diastolic pressure-volume relationship was unchanged (1.5 ± 0.9 vs 1.6 ± 1.3; P = .733). Compared with baseline, atrial fibrillation resulted in a significantly higher contribution of left atrial reservoir volume to stroke volume (32% vs 17%; P = .005) and lower left atrial booster pump volume contribution to stroke volume (19% vs 28%; P = .029). Atrial fibrillation also significantly increased maximum left atrial volume (206 ± 41 mL vs 90 ± 21 mL; P < .001). Left atrial fibrosis in group 2 was significantly higher than in group 1. Atrial fibrillation decreased left ventricular ejection fraction (29% ± 9% vs 58 ± 8%; P < .001), but left ventricular stroke volume was unchanged.</AbstractText>In a chronic model of atrial fibrillation, the left atrium demonstrated significant structural remodeling and decreased contractility. These data suggest that early intervention in patients with persistent atrial fibrillation might mitigate against adverse atrial and ventricular structural remodeling.</AbstractText>Copyright © 2015 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
10,274 | Genetic defects in a His-Purkinje system transcription factor, IRX3, cause lethal cardiac arrhythmias. | Ventricular fibrillation (VF), the main cause of sudden cardiac death (SCD), occurs most frequently in the acute phase of myocardial infarction: a certain fraction of VF, however, develops in an apparently healthy heart, referred as idiopathic VF. The contribution of perturbation in the fast conduction system in the ventricle, the His-Purkinje system, for idiopathic VF has been implicated, but the underlying mechanism remains unknown. Irx3/IRX3 encodes a transcription factor specifically expressed in the His-Purkinje system in the heart. Genetic deletion of Irx3 provides a mouse model of ventricular fast conduction disturbance without anatomical or contraction abnormalities. The aim of this study was to examine the link between perturbed His-Purkinje system and idiopathic VF in Irx3-null mice, and to search for IRX3 genetic defects in idiopathic VF patients in human.</AbstractText>Telemetry electrocardiogram recording showed that Irx3-deleted mice developed frequent ventricular tachyarrhythmias mostly at night. Ventricular tachyarrhythmias were enhanced by exercise and sympathetic nerve activation. In human, the sequence analysis of IRX3 exons in 130 probands of idiopathic VF without SCN5A mutations revealed two novel IRX3 mutations, 1262G>C (R421P) and 1453C>A (P485T). Ventricular fibrillation associated with physical activities in both probands with IRX3 mutations. In HL-1 cells and neonatal mouse ventricular myocytes, IRX3 transfection up-regulated SCN5A and connexin-40 mRNA, which was attenuated by IRX3 mutations.</AbstractText>IRX3 genetic defects and resultant functional perturbation in the His-Purkinje system are novel genetic risk factors of idiopathic VF, and would improve risk stratification and preventive therapy for SCD in otherwise healthy hearts.</AbstractText>Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.</CopyrightInformation> |
10,275 | Dyscholesterolemia Protects Against Ischemia-Induced Ventricular Arrhythmias. | Hypercholesterolemia protects against ventricular fibrillation in patients with myocardial infarction. We hypothesize that hypercholesterolemia protects against ischemia-induced reentrant arrhythmias because of altered ion channel function.</AbstractText>ECGs were measured in low-density lipoprotein receptor knockout (LDLr(-/-)), apolipoprotein A1 knockout (ApoA1(-/-)), and wild-type (WT) mice. Action potentials, calcium handling, and ion currents were recorded in ventricular myocytes. Gene expression was determined by quantitative polymerase chain reaction and Western blot. In isolated perfused hearts, regional ischemia was induced and arrhythmia inducibility was tested. Serum low-density lipoprotein (LDL) cholesterol was higher in LDLr(-/-) mice than in WT mice (2.6 versus 0.4 mmol/L), and high-density lipoprotein cholesterol was significantly lower in ApoA1(-/-) mice than in WT mice (0.3 versus 1.8 mmol/L). LDLr(-/-) and ApoA1(-/-) myocytes contained more cholesterol than WT (34.4±2.8 and 36.5±2.4 versus 25.5±0.4 μmol/g protein). The major potassium currents were not different in LDLr(-/-) and ApoA1(-/-) compared with WT mice. The L-type calcium current (I(Ca)), however, was larger in LDLr(-/-) and ApoA1(-/-) than in WT (12.1±0.7 and 12.8±0.8 versus 9.4±1.1 pA/pF). Calcium transient amplitude and fractional sarcoplasmic reticulum calcium release were larger and action potential and QTc duration longer in LDLr(-/-) and ApoA1(-/-) than in WT mice (action potential duration at 90% of repolarization: 102±4 and 106±3 versus 84±3.1 ms; QTc: 50.9±1.3 and 52.8±0.8 versus 43.5±1.2 ms). During ischemia, ventricular tachycardia/ventricular fibrillation inducibility was larger in WT than in LDLr(-/-) and ApoA1(-/-) hearts. Expression of sodium channel and Ca-handling genes were not significantly different between groups.</AbstractText>Dyscholesterolemia is associated with action potential prolongation because of increased I(Ca) and reduces occurrence of reentrant arrhythmias during ischemia.</AbstractText>© 2015 American Heart Association, Inc.</CopyrightInformation> |
10,276 | Potentially fatal arrhythmias in two cases of adult Kawasaki disease. | Fatal arrhythmias in asymptomatic Kawasaki disease patients with normal left ventricular function have rarely been reported. In this study, we report the cases of two adult patients with largely unpredictable sudden cardiac arrest, despite almost-normal left ventricular function even after the diagnosis of presumed Kawasaki disease, as well as consider the mechanisms involved with reference to the literature. |
10,277 | Rate-dependent Loss of Capture during Ventricular Pacing. | A 63-year-old patient who had undergone atrial septal defect surgical repair received implantation of a single chamber VVI pacemaker for long RR intervals during atrial fibrillation. One week later, an intermittent loss of capture and sensing failure was detected at a pacing rate of 70 beats/min. However, a successful capture was observed during rapid pacing. Consequently, the pacing rate was temporarily adjusted to 90 beats/min. At the 3-month follow-up, the pacemaker was shown to be functioning properly independent of the pacing rate. An echocardiogram showed that the increased pacing rates were accompanied by a reduction in the right ventricular outflow tract dimension. The pacemaker was then permanently programmed at a lower rate of 60 beats/min. |
10,278 | A ventilation technique for oxygenation and carbon dioxide elimination in CPR: Continuous insufflation of oxygen at three levels of pressure in a pig model. | Pulmonary ventilation remains an important part of cardiopulmonary resuscitation, affecting gas exchange and haemodynamics. We designed and studied an improved method of ventilation for CPR, constructed specifically to support both gas exchange and haemodynamics. This method uses continuous insufflation of oxygen at three levels of pressure, resulting in tri-level pressure ventilation (TLPV). We hypothesized that TLPV improves gas exchange and haemodynamics compared to manual gold standard ventilation (GSV).</AbstractText>In 14 pigs, ventricular fibrillation was induced and automated CPR performed for 10 min with either TLPV or GSV. After defibrillation, CPR was repeated with the other ventilation method. Gas exchange and haemodynamics were monitored. Data are presented as mean±standard error of the mean.</AbstractText>TLPV was superior to GSV for PaO2 (163±36 mmHg difference; P=0.001), and peak AWP (-20±2 cmH2O difference; P=0.000) and higher for mean AWP (8±0.2 cmH2O difference; P=0.000). TLPV was comparable to GSV for CPP (5±3 mmHg difference; P=0.012), VCO2 (0.07±0.3 mL/min/kg difference; P=0.001), SvO2 (4±3%-point; P=0.001), mean carotid flow (-0.5±4 mL/min difference; P=0.016), and pHa (0.00±0.03 difference; P=0.002). The PaCO2 data do not provide a conclusive result (4±4 mmHg difference).</AbstractText>We conclude that the ventilation strategy with a tri-level pressure cycle performs comparable to an expert, manual ventilator in an automated-CPR swine model.</AbstractText>Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
10,279 | Simplified Method for Vagal Effect Evaluation in Cardiac Ablation and Electrophysiological Procedures. | The aim of this study is to show a simplified reversible approach to investigate and confirm vagal denervation at any time during the ablation procedure without autonomic residual effect.</AbstractText>Parasympathetic denervation has been increasingly applied in ablation procedures such as in vagal-related atrial fibrillation and cardioneuroablation. This method proposes an easy way to study the vagal effect and to confirm its elimination following parasympathetic denervation through vagal stimulation (VS) by an electrophysiological catheter placed in the internal jugular vein.</AbstractText>A prospective controlled study including 64 patients without significant cardiopathy (48 male [75.0%], age 46.4 ± 16.4 years) who had a well-defined RF ablation indication for symptomatic arrhythmias, comprising a "denervation group" (DG), with indication for ablation with parasympathetic denervation (vagal-related atrial fibrillation or severe cardioinhibitory syncope) and a "control group" (CG), with ablation indication without parasympathetic denervation (accessory pathway or ventricular arrhythmia). By using a neurostimulator, both groups underwent non simultaneous bilateral VS (8 to 12 s, frequency: 30 Hz, pulse width: 50 μs, amplitude: 0.5 to 1 V/kg up to 70 V) through the internal jugular vein pre- and post-ablation.</AbstractText>Significant cardioinhibition was achieved pre-ablation in all cases (pause of 11.5 ± 1.9 s in DG vs. 11.4 ± 2.1 s in CG; p = 0.79). Eight patients (12.5%) presented catheter progression difficulty in 1 jugular vein (2 right, 6 left); however, the contralateral VS was adequate for cardioinhibition. After ablation, the cardioinhibition was reproduced only in CG (pause of 11.2 ± 2.2 s) as in DG it was entirely eliminated. There was no significant difference between pre- and post-ablation cardioinhibition in CG (p = 0.84). There was no complication (follow-up 8.8 ± 5 months).</AbstractText>The vagal stimulation was feasible, easy, and reliable, and showed no complications. It may be repeated during the procedure to control the denervation degree without residual effect. It could be a suitable tool for vagal denervation confirmation or autonomic tests during electrophysiological studies. Ablation without parasympathetic denervation did not change the vagal response.</AbstractText>Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
10,280 | The Effect of Contact Force in Atrial Radiofrequency Ablation: Electroanatomical, Cardiovascular Magnetic Resonance, and Histological Assessment in a Chronic Porcine Model. | This study sought to determine the effect of contact force (CF) on atrial lesion size, quality, and transmurality by using a chronic porcine model of radiofrequency ablation.</AbstractText>CF is a major determinant of ventricular lesion formation, but uncertainty exists regarding the most appropriate CF parameters to safely achieve permanent, transmural lesions in the atria.</AbstractText>Intercaval linear ablation (30 W, 42°C, 17 ml/min irrigation) was performed in 8 Göttingen minipigs by using a force-sensing catheter with CF >20 g (high force) or <10 g (low force) at alternate ends of the line, separated by an intentional gap. Voltage mapping and cardiovascular magnetic resonance (CMR) imaging were performed pre-ablation, immediately after ablation, and at 2 months' post-procedure. Lesions were sectioned orthogonal to the axis of ablation to assess transmurality.</AbstractText>Mean CF was 22.6 ± 11.4 g and 7.8 ± 4.0 g in the high and low CF regions. Acute tissue edema was greater with high CF, both caudally (7.0 mm vs. 4.6 mm; p = 0.016) and cranially (6.9 mm vs. 4.6 mm; p = 0.038). There was no difference in chronic lesion size (voltage mapping) or volume (late gadolinium enhancement CMR) between high and low CF regions. There was no difference in scar density (assessed by low-voltage criteria and late gadolinium enhancement signal intensity) or histological transmurality between high and low CF regions.</AbstractText>Although high CF (>20 g) resulted in more acute tissue edema than low CF (<10 g), chronically there was no difference in lesion size, quality, or transmurality. Appropriate CF targets for atrial ablation may be lower than previously thought.</AbstractText>Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
10,281 | Utility of a Novel Rapid High-Resolution Mapping System in the Catheter Ablation of Arrhythmias: An Initial Human Experience of Mapping the Atria and the Left Ventricle. | This study sought to assess the clinical efficacy, safety, and clinical utility of a novel electroanatomical mapping system.</AbstractText>A new mapping system capable of rapidly acquiring detailed maps based on automatic annotation of thousands of points was recently released for clinical use. This is the first description of its utility in humans.</AbstractText>The first consecutive 20 cases (7 atrial tachycardia, 8 atrial fibrillation, 3 ventricular tachycardia, and 2 ventricular ectopic beat ablations) were analyzed. The system uses a bidirectional deflectable basket catheter with 64 closely spaced mini-electrodes. It automatically accepts and annotates electrograms when a number of predefined criteria are met.</AbstractText>Thirty right atrial maps were acquired in 11 (4 to 15) min, consisting of 7,220 (3,467 to 10,947) points, 22 left atrial maps in 11 (6 to 19) min, consisting of 7,818 (4,379 to 12,262) points and 10 left ventricular maps in 37 (14 to 43) min, consisting of 8,709 (2,605 to 15,514) points. The mini-basket catheter could reach all areas of interest without deflectable sheaths. No embolic events, bleeding complications, or endocardial structure damage were observed. Correction of the automatic annotation was performed in 0.02% of points in 4 of 62 maps. The system revealed re-entry circuits of atrial tachyarrhythmias, identified gaps on linear lesions, and identified and correctly annotated the clinical ventricular ectopic beats and channels of slow conduction within ventricular scar.</AbstractText>The novel automatic mapping system was rapid, safe, and efficacious in mapping a variety of cardiac arrhythmias in humans. Further clinical research is needed to optimize its use in the ablation of complex arrhythmias.</AbstractText>Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
10,282 | Low-Level Electrical Stimulation of Aortic Root Ventricular Ganglionated Plexi Attenuates Autonomic Nervous System-Mediated Atrial Fibrillation. | This study investigated the effect of electrical stimulation of aortic root ventricular ganglionated plexi (GP) on atrial fibrillation (AF) inducibility.</AbstractText>The ventricular GP are interconnected with atrial GP to govern heart function, although the effect of ventricular GP modification on control of AF remains unknown.</AbstractText>Effective refractory periods (ERPs) of test pulmonary veins (PVs) were measured at baseline and during high-level (HL-ES) and low-level (LL-ES) electrical stimulation of the aortic root GP. The arrhythmogenic threshold of acetylcholine and isoproterenol was determined at baseline and during HL-ES and LL-ES. Moreover, AF was induced at PVs by programmed electrical stimulation after HL-ES or LL-ES. Immunohistochemistry staining was performed to examine the autonomic activity from aortic root GP to the PVs.</AbstractText>Compared with the baseline group, HL-ES of aortic root GP significantly shortened atrial ERP (95 ± 13 ms vs. 122 ± 9 ms) and PV ERP (104 ± 11 ms vs. 131 ± 12 ms); decreased the threshold concentration of AF by both acetylcholine (1.3 ± 0.2 μmol/l vs. 3.2 ± 0.3 μmol/l) and isoproterenol (0.3 ± 0.1 μmol/l vs. 1.3 ± 0.2 μmol/l); and increased the AF-inducing rate from PVs (90% vs. 30%). In contrast, LL-ES of the GP prevented the shortening of ERP and PV ERP to 125 ± 10 ms and 133 ± 11 ms, respectively; increased threshold levels of acetylcholine and isoproterenol to 5.7 ± 0.4 μmol/l and 3.2 ± 0.3 μmol/l; and decreased the AF-inducing rate to 5%. We also found that the biotinylated dextran amine-containing varicose fibers projected directly from the aortic root GP to the left PVs.</AbstractText>These findings suggest that autonomic innervations of left PVs partly originated from aortic root ventricular GP. Moreover, LL-ES of aortic root ventricular GP suppressed AF inducibility and arose from PVs mediated by the autonomic nervous system.</AbstractText>Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
10,283 | [Contribution of atrial activation to the segment of the typical atrial flutter wave: an electro-anatomic insight into the electrocardiogram morphology]. | To investigate how the intra-cardiac activation was translates into the characterized flutter wave in patients with cavatricuspid isthmus-dependent counter-clockwise atrial flutter (CTI-AFL).</AbstractText>A total of 15 hospitalized CTI-AFL patients (mean age: (60 ± 14) years old, 1 female) from October 2012 to February 2014 were enrolled in the study. The activation map was re-constructed during AFL rhythm for left atrium and right atrium using 3-dimensional mapping system. The flutter wave in surface electrocardiogram was analyzed in combination with the intra-cardiac activation.</AbstractText>The mean left ventricular ejection fraction was (60.8 ± 6.6)%, and the left atrial diameter was (39.0 ± 3.4) mm. The mean tachycardia cycle length was (220 ± 24) ms. The activation map was completed in all cases. In inferior leads, the flutter wave was divided into three parts: slowly downward part, sharp downward part and the terminal positive part. The three parts corresponded to the fixed activation part of the macro-reentry.</AbstractText>The distinctive flutter wave of CTI-AFL was determined by the unique macro-reentry activation in the right atrium. The activation of left atrium contributes to the downward part of the wave.</AbstractText> |
10,284 | Relationship between J Waves and Vagal Activity in Patients Who Do Not Have Structural Heart Disease. | J waves are associated with increased vagal activity in patients with idiopathic ventricular fibrillation in several studies to date. However, the relationship between J waves and autonomic nervous activity in patients without structural heart disease remains under investigation. We investigated whether the presence of a J wave on the surface electrocardiogram (ECG) was related to increased vagal activity in patients without structural heart disease.</AbstractText>This retrospective study included 684 patients without structural heart disease who had undergone Holter ECG and surface ECG monitoring. Based on the presence of J waves on the surface ECG, patients were divided into two groups: those with J waves (group 1) and those without J waves (group 2). We compared heart rate variability (HRV), reflecting autonomic nervous activity, using 24-h Holter ECG between the groups.</AbstractText>J waves were present in 92 (13.4%) patients. Heart rate (HR) in group 1 was significantly lesser than that in group 2 (P = 0.031). The ratio of low-frequency (LF) components to high-frequency (HF) components (LF/HF) in group 1 was significantly lower than that in group 2 (P = 0.001). The square root of the mean squared differences of successive NN intervals in group 1 was also significantly higher than that in group 2 (P = 0.047). In a multivariate regression analysis, male sex, HR, and LF/HF ratio remained independent determinants for the presence of J waves (P = 0.039, P = 0.036, and P < 0.001, respectively).</AbstractText>In patients without structural heart disease, the presence of a J wave was associated with a slow HR, male sex, and increased vagal activity, independently.</AbstractText>© 2015 Wiley Periodicals, Inc.</CopyrightInformation> |
10,285 | Cardiac arrest following butane inhalation. | Butane is a commonly misused volatile agent, and a cause of intoxication. We present a case, who had a syncope and persistent ventricular fibrillation during the course of resuscitation. We discussed the management of this case in the intensive care unit and the accompanying difficulties in the light of the current literature. |
10,286 | Supraventricular Tachycardia Classification in the 12-Lead ECG Using Atrial Waves Detection and a Clinically Based Tree Scheme. | Specific supraventricular tachycardia (SVT) classification using surface ECG is considered a challenging task, since the atrial electrical activity (AEA) waves, which are a crucial element for obtaining diagnosis, are frequently hidden. In this paper, we present a fully automated SVT classification method that embeds our recently developed hidden AEA detector in a clinically based tree scheme. The process begins with initial noise removal and QRS detection. Then, ventricular features are extracted. According to these features, an initial AEA-wave search window is defined and a single AEA-wave is detected. Using a synthetic Gaussian signal and a linear combination of 12-lead ECG signals, all AEA-waves are detected. In accord with the atrial and ventricular information found, classification to atrial fibrillation, atrial flutter, atrioventricular nodal reentry tachycardia, atrioventricular reentry tachycardia, or sinus rhythm is performed in the framework of a clinically oriented decision tree. A study was performed to evaluate the classification from 68 patients (26 were used for the classifier's design, 42 were used for its validation). Average sensitivity of 83.21% [95% confidence interval (CI): 79.33-86.49%], average specificity of 95.80% (95% CI: 94.73-96.67%), and average accuracy of 93.29% (95% CI: 92.13-94.28%) were achieved compared to the definite diagnosis. In conclusion, the presented method may serve as a valuable decision support tool, allowing accurate detection of SVTs using noninvasive means. |
10,287 | Is lower base rate detrimental to transcatheter aortic valve implantation patients requiring pacemakers? | Sudden cardiac death related to polymorphic ventricular tachycardia/ventricular fibrillation has been well reported post atrioventricular junction ablation. The practice of faster pacing rate immediately after atrioventricular junction ablation is well recognized to decrease the risk of sudden cardiac death. We propose that this practice (faster pacing rate) be implemented in patients who need permanent pacemakers secondary to transcatheter aortic valve implantation (or even surgical aortic valve interventions). |
10,288 | Predict Defibrillation Outcome Using Stepping Increment of Poincare Plot for Out-of-Hospital Ventricular Fibrillation Cardiac Arrest. | Early cardiopulmonary resuscitation together with early defibrillation is a key point in the chain of survival for cardiac arrest. Optimizing the timing of defibrillation by predicting the possibility of successful electric shock can guide treatments between defibrillation and cardiopulmonary resuscitation and improve the rate of restoration of spontaneous circulation. Numerous methods have been proposed for predicting defibrillation success based on quantification of the ventricular fibrillation waveform during past decades. To date, however, no analytical technique has been widely accepted for clinical application. In the present study, we investigate whether median stepping increment that is calculated from the Euclidean distance of consecutive points in Poincare plot could be used to predict the likelihood of successful defibrillation. Electrocardiographic recordings of out-of-hospital cardiac arrest patients were obtained from the external defibrillators. The performance of the proposed method was evaluated by receiver operating characteristic curve and compared with the results of other established features. The results indicated that median stepping increment has comparable performance to the established methods in predicting the likelihood of successful defibrillation. |
10,289 | Electrical storm: A clinical and electrophysiological overview. | Electrical storm (ES) is a clinical condition characterized by three or more ventricular arrhythmia episodes leading to appropriate implantable cardioverter-defibrillator (ICD) therapies in a 24 h period. Mostly, arrhythmias responsible of ES are multiple morphologies of monomorphic ventricular tachycardia (VT), but polymorphic VT and ventricular fibrillation can also result in ES. Clinical presentation is very dramatic in most cases, strictly related to the cardiac disease that may worsen electrical and hemodynamic decompensation. Therefore ES management is challenging in the majority of cases and a high mortality is the rule both in the acute and in the long-term phases. Different underlying cardiomyopathies provide significant clues into the mechanism of ES, which can arise in the setting of structural arrhythmogenic cardiomyopathies or rarely in patients with inherited arrhythmic syndrome, impacting on pharmacological treatment, on ICD programming, and on the opportunity to apply strategies of catheter ablation. This latter has become a pivotal form of treatment due to its high efficacy in modifying the arrhythmogenic substrate and in achieving rhythm stability, aiming at reducing recurrences of ventricular arrhythmia and at improving overall survival. In this review, the most relevant epidemiological and clinical aspects of ES, with regard to the acute and long-term follow-up implications, were evaluated, focusing on these novel therapeutic strategies of treatment. |
10,290 | Modified Maze Procedure for Atrial Fibrillation as an Adjunct to Elective Cardiac Surgery: Predictors of Mid-Term Recurrence and Echocardiographic Follow-Up. | The radiofrequency maze procedure achieves sinus rhythm in 45%-95% of patients treated for atrial fibrillation. This retrospective study evaluates mid-term results of the radiofrequency maze-performed concomitant to elective cardiac surgery-to determine sinus-rhythm predictive factors, and describes the evolution of patients' echocardiographic variables. From 2003 through 2011, 247 patients (mean age, 64 ± 9.5 yr) with structural heart disease (79.3% mitral disease) and atrial fibrillation underwent a concomitant radiofrequency modified maze procedure. Patients were monitored by 24-hour Holter at 3, 6, 12, and 24 months, then annually. Eighty-four mitral-valve patients underwent regular echocardiographic follow-up. Univariate and multivariate analysis for risk factors of maze failure were identified. The in-hospital mortality rate was 1.2%. During a median follow-up of 39.4 months, the late mortality rate was 3.6%, and pacemaker insertion was necessary in 26 patients (9.4%). Sinus rhythm was present in 63% of patients at the latest follow-up. Predictive factors for atrial fibrillation recurrence were arrhythmia duration (hazard ratio [HR]=1.296, P=0.045) and atrial fibrillation at hospital discharge (HR=2.03, P=0.019). The monopolar device favored maze success (HR=0.191, P <0.0001). Left atrial area and indexed left ventricular end-diastolic volume showed significant decrease both in sinus rhythm and atrial fibrillation patients. Early sinus rhythm conversion was associated with improved left ventricular ejection fraction. Concomitant radiofrequency maze procedure provided remarkable outcomes. Shorter preoperative atrial fibrillation duration, monopolar device use, and prompt treatment of arrhythmia recurrences increase the midterm success rate. Early sinus rhythm restoration seems to result in better left ventricular ejection fraction recovery. |
10,291 | Update on the Diagnosis and Management of Brugada Syndrome. | Brugada Syndrome (BrS) is an autosomal dominant channelopathy with variable penetrance affecting the sodium channel. It reduces the transport of sodium ions essential for proper generation of the cardiac action potential. The resulting inhomogeneous repolarisation in areas of the RV epicardium causes malignant ventricular arrhythmias. BrS is diagnosed by typical cove shaped ST elevation of > 2mm in ≥1 RV precordial lead V1, V2 occurring spontaneously or after provocative drug test with IV administration of Class 1 antiarrhythmic drug such as flecainide or ajmaline. The incidence of BrS is variable being higher in South East Asians and is generally quoted as 1:2000. It is responsible for up to 20% of sudden arrhythmic deaths in those without structural heart disease. Typical presentation is syncope or resuscitated sudden death and symptoms usually occur at night or at rest especially after a large meal. Fever is a common trigger, particularly in children. Genetic testing for BrS is a Class 2A indication and the yield has increased recently to nearly 40%. Genetic testing assists with family screening. |
10,292 | Ischemic Postconditioning and Nitric Oxide Administration Failed to Confer Protective Effects in a Porcine Model of Extracorporeal Cardiopulmonary Resuscitation. | The protective effects of ischemic postconditioning (IPC) and nitric oxide (NO) administration have been demonstrated in several ischemic scenarios. However, current evidence regarding the effect of IPC and NO in extracorporeal cardiopulmonary resuscitation remains lacking. Fifteen female swine (body weight 45 kg) underwent veno-arterial extracorporeal membrane oxygenation (ECMO) implantation; cardiac arrest-ventricular fibrillation was induced by rapid ventricular pacing. After 20 min of cardiac arrest, blood flow was restored by increasing the ECMO flow rate to 4.5 L/min. The animals (five per group) were then randomly assigned to receive IPC (three cycles of 3 min ischemia and reperfusion), NO (80 ppm via oxygenator), or mild hypothermia (HT; 33.0°C). Cerebral oximetry and aortic blood pressure were monitored continuously. After 90 min of reperfusion, blood samples were drawn for the measurement of troponin I, myoglobin, creatine-phosphokinase, alanine aminotransferase, neuron-specific enolase, cystatin C, and reactive oxygen metabolite (ROM) levels. Significantly higher blood pressure and cerebral oxygen saturation values were observed in the HT group compared with the IPC and NO groups (P < 0.05). The levels of troponin I, myoglobin, creatine phosphokinase, and alanine aminotransferase were significantly lower in the HT group (P < 0.05); levels of neuron-specific enolase, cystatin C, and ROM were not significantly different. IPC and NO were comparable in all monitored parameters. The results of the present study indicate that IPC and NO administration are not superior interventions to HT for the maintenance of blood pressure, cerebral oxygenation, organ protection, and suppression of oxidative stress following extracorporeal cardiopulmonary resuscitation. |
10,293 | Prophylactic and Therapeutic Effects of Oleuropein on Reperfusion-Induced Arrhythmia in Anesthetized Rat. | This study was conducted to reveal that whether i.v. injection of oleuropein, the most potent polyphenolic antioxidant in olive leaf, has any effect on the magnitude of reperfusion arrhythmia in anesthetized rats or not.</AbstractText>Eighty male Wistar rats were divided into 8 groups of 10 each: groups 1 and 5 were assigned as the prophylactic and treatment control groups, groups 2 and 6 as the prophylactic and treatment groups with lidocaine (10 mg/kg), groups 3 and 4 as the prophylactic groups with 10 and 50 mg/kg oleuropein (i.v.), and groups 7 and 8 as the treatment groups with 10 and 50 mg/kg oleuropein (i.v.), respectively. Reperfusion injury was induced by 5-min regional ischemia and 15-min reperfusion of left anterior descending coronary artery. Heart rate, blood pressure, and electrocardiogram were monitored throughout the procedure.</AbstractText>blood pressure was significantly decreased by infusion of 50 mg/kg oleuropein in groups 4 and 8, but unlike the lidocaine as a standard anti-arrhythmic drug in groups 2 and 5 had not significant effect on heart rate. The onset of arrhythmia in groups received oleuropein (groups 3, 4, 7, and 8) was significantly delayed. The mortality rate due to irreversible ventricular fibrillation was also significantly reduced in groups 3, 4, 7, and 8. The effect of lidocaine in groups 2 and 5 was more potent than that in oleuropein group.</AbstractText>These findings indicate that i.v. injection of oleuropein possibly through its antioxidant activity reduces the magnitude of reperfusion-induced arrhythmia.</AbstractText> |
10,294 | Prediction of ventricular arrhythmia events in ischemic heart disease patients with implantable cardioverter-defibrillators. | The aim of the study was to exam the prediction of ventricular arrhythmia events in ischemic heart disease patients with implantable cardioverter-defibrillators (ICD). A total of 123 consecutive patients confirmed ischemia heart disease with ICD were examined. After device implantation, the occurrence of appropriate ICD therapy was noted. Patients were divided into two groups according to the ventricular arrhythmia occurrence. Patients with ventricular arrhythmia occurrence had a significantly great incidence of atrial fibrillation history compare to the no-ventricular arrhythmia occurrence group (8 vs. 39%, P = 0.02). The level of high-sensitive C-reactive protein (hsCRP) baseline was also significantly higher in the ventricular arrhythmia group than in the no ventricular arrhythmia (3.78 ± 1.1 vs. 0.94 ± 0.7, P < 0.01). The taking of β blocker is not common in ventricular arrhythmia group patients than no ventricular arrhythmia group (5 vs. 29%, P = 0.03). By univariate comparison, male sex, the history of atrial fibrillation, and a high level of hsCRP were significant predictors for ventricular arrhythmia occurrence. By multivariate analysis, the atrial fibrillation burden, and had a high level of hsCRP were significant for incidence of ventricular arrhythmia occurrence in ischemic heart disease patients. β-block were more likely to be free from ventricular arrhythmia occurrence. The high level of hsCRP, and the atrial fibrillation burden were strong predictor of ventricular arrhythmia occurrence in secondary prevention ICD recipients with ischemic heart disease. Taking β-blockers was free from ventricular arrhythmia occurrence. |
10,295 | Risk Stratification for Arrhythmic Events in Patients With Asymptomatic Pre-Excitation: A Systematic Review for the 2015 ACC/AHA/HRS Guideline for the Management of Adult Patients With Supraventricular Tachycardia: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society. | To review the literature systematically to determine whether noninvasive or invasive risk stratification, such as with an electrophysiological study of patients with asymptomatic pre-excitation, reduces the risk of arrhythmic events and improves patient outcomes.</AbstractText>PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials (all January 1, 1970, through August 31, 2014) were searched for randomized controlled trials and cohort studies examining noninvasive or invasive risk stratification in patients with asymptomatic pre-excitation. Studies were rejected for low-quality design or the lack of an outcome, population, intervention, or comparator of interest or if they were written in a language other than English.</AbstractText>Of 778 citations found, 9 studies met all the eligibility criteria and were included in this paper. Of the 9 studies, 1 had a dual design-a randomized controlled trial of ablation versus no ablation in 76 patients and an uncontrolled prospective cohort of 148 additional patients-and 8 were uncontrolled prospective cohort studies (n=1,594). In studies reporting a mean age, the range was 32 to 50 years, and in studies reporting a median age, the range was 19 to 36 years. The majority of patients were male (range, 50% to 74%), and <10% had structural heart disease. In the randomized controlled trial component of the dual-design study, the 5-year Kaplan-Meier estimates of the incidence of arrhythmic events were 7% among patients who underwent ablation and 77% among patients who did not undergo ablation (relative risk reduction: 0.08; 95% confidence interval: 0.02 to 0.33; p<0.001). In the observational cohorts of asymptomatic patients who did not undergo catheter ablation (n=883, with follow-up ranging from 8 to 96 months), regular supraventricular tachycardia or benign atrial fibrillation (shortest RR interval >250 ms) developed in 0% to 16%, malignant atrial fibrillation (shortest RR interval ≤250 ms) in 0% to 9%, and ventricular fibrillation in 0% to 2%, most of whom were children in the last case.</AbstractText>The existing evidence suggests risk stratification with an electrophysiological study of patients with asymptomatic pre-excitation may be beneficial, along with consideration of accessory-pathway ablation in those deemed to be at high risk of future arrhythmias. Given the limitations of the existing data, well-designed and well-conducted studies are needed.</AbstractText>Copyright © 2016 American College of Cardiology Foundation, the American Heart Association, Inc., and the Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
10,296 | Risk stratification for arrhythmic events in patients with asymptomatic pre-excitation: A systematic review for the 2015 ACC/AHA/HRS guideline for the management of adult patients with supraventricular tachycardia: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society. | To review the literature systematically to determine whether noninvasive or invasive risk stratification, such as with an electrophysiological study of patients with asymptomatic pre-excitation, reduces the risk of arrhythmic events and improves patient outcomes.</AbstractText>PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials (all January 1, 1970, through August 31, 2014) were searched for randomized controlled trials and cohort studies examining noninvasive or invasive risk stratification in patients with asymptomatic pre-excitation. Studies were rejected for low-quality design or the lack of an outcome, population, intervention, or comparator of interest or if they were written in a language other than English.</AbstractText>Of 778 citations found, 9 studies met all the eligibility criteria and were included in this paper. Of the 9 studies, 1 had a dual design-a randomized controlled trial of ablation versus no ablation in 76 patients and an uncontrolled prospective cohort of 148 additional patients-and 8 were uncontrolled prospective cohort studies (n=1,594). In studies reporting a mean age, the range was 32 to 50 years, and in studies reporting a median age, the range was 19 to 36 years. The majority of patients were male (range, 50% to 74%), and <10% had structural heart disease. In the randomized controlled trial component of the dual-design study, the 5-year Kaplan-Meier estimates of the incidence of arrhythmic events were 7% among patients who underwent ablation and 77% among patients who did not undergo ablation (relative risk reduction: 0.08; 95% confidence interval: 0.02 to 0.33; p<0.001). In the observational cohorts of asymptomatic patients who did not undergo catheter ablation (n=883, with follow-up ranging from 8 to 96 months), regular supraventricular tachycardia or benign atrial fibrillation (shortest RR interval >250 ms) developed in 0% to 16%, malignant atrial fibrillation (shortest RR interval ≤250 ms) in 0% to 9%, and ventricular fibrillation in 0% to 2%, most of whom were children in the last case.</AbstractText>The existing evidence suggests risk stratification with an electrophysiological study of patients with asymptomatic pre-excitation may be beneficial, along with consideration of accessory-pathway ablation in those deemed to be at high risk of future arrhythmias. Given the limitations of the existing data, well-designed and well-conducted studies are needed.</AbstractText>Copyright © 2016 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
10,297 | Electrocardiogram and Chagas disease: a large population database of primary care patients. | Chagas disease (ChD) used to be a disease restricted to Latin America, but has become a worldwide problem due to migration of infected individuals to developed countries. Electrocardiography has been considered an essential exam to evaluate ChD patients.</AbstractText>This study sought to identify prevalent electrocardiographic abnormalities in a large sample of ChD patients evaluated in the primary care setting.</AbstractText>This retrospective observational study assessed all consecutive digital 12-lead electrocardiograms (ECG) performed by the Telehealth Network of Minas Gerais, Brazil, from January 1 to December 31, 2011. In that time, the service attended primary care patients in 660 cities in the Minas Gerais province. ChD was self-reported, and the individuals who did not report having ChD were considered noninfected. The prevalence of electrocardiographic abnormalities was assessed.</AbstractText>Self-reported ChD patients comprised 7,590 (2.9%) of 264,324 patients who underwent ECG during the study period. The mean age for ChD patients was 57.0 ± 13.7 years, and 64.1% of patients were women. The most common comorbidities were hypertension (61.3%), diabetes (9.1%), and dyslipidemia (6.9%), and 10.7% were smokers. The most frequent electrocardiographic abnormalities were nonspecific repolarization abnormalities (34.6%), right bundle branch block (RBBB) (22.7%), left anterior hemiblock (LAH) (22.5%), ventricular premature beats (5.4%), and atrial fibrillation (5.4%). Only 31.5% of the patients had no electrocardiographic abnormality versus 61.2% in noninfected individuals (p < 0.001). The prevalence of normal ECG decreased with aging and was significantly lower than for noninfected individuals in all age groups. Pacemaker rhythm (odds ratio [OR]: 13.3, 95% confidence intervals [CI]: 11.5 to 15.4), RBBB (OR: 10.7, 95% CI: 10.1 to 11.4), especially in association with LAH (OR: 12.1, 95% CI: 11.2 to 13.0), second atrioventricular block (OR: 4.1, 95% CI: 2.5 to 6.6), and third atrioventricular block (OR: 13.3, 95% CI: 11.5 to 15.4) were strongly related to ChD.</AbstractText>In this large sample of primary care patients with ChD, there was a high prevalence of electrocardiographic abnormalities. Pacemaker rhythm, RBBB, especially in association with LAH, and second and third atrioventricular block were strongly related to ChD.</AbstractText>Copyright © 2015 World Heart Federation (Geneva). Published by Elsevier B.V. All rights reserved.</CopyrightInformation> |
10,298 | Cardiac shear-wave elastography using a transesophageal transducer: application to the mapping of thermal lesions in ultrasound transesophageal cardiac ablation. | Heart rhythm disorders, such as atrial fibrillation or ventricular tachycardia can be treated by catheter-based thermal ablation. However, clinically available systems based on radio-frequency or cryothermal ablation suffer from limited energy penetration and the lack of lesion's extent monitoring. An ultrasound-guided transesophageal device has recently successfully been used to perform High-Intensity Focused Ultrasound (HIFU) ablation in targeted regions of the heart in vivo. In this study we investigate the feasibility of a dual therapy and imaging approach on the same transesophageal device. We demonstrate in vivo that quantitative cardiac shear-wave elastography (SWE) can be performed with the device and we show on ex vivo samples that transesophageal SWE can map the extent of the HIFU lesions. First, SWE was validated with the transesophageal endoscope in one sheep in vivo. The stiffness of normal atrial and ventricular tissues has been assessed during the cardiac cycle (n = 11) and mapped (n = 7). Second, HIFU ablation has been performed with the therapy-imaging transesophageal device in ex vivo chicken breast samples (n  =  3), then atrial (left, n = 2) and ventricular (left n = 1, right n = 1) porcine heart tissues. SWE provided stiffness maps of the tissues before and after ablation. Areas of the lesions were obtained by tissue color change with gross pathology and compared to SWE. During the cardiac cycle stiffness varied from 0.5   ±   0.1 kPa to 6.0   ±   0.3 kPa in the atrium and from 1.3   ±   0.3 kPa to 13.5   ±   9.1 kPa in the ventricles. The thermal lesions were visible on all SWE maps performed after ablation. Shear modulus of the ablated zones increased to 16.3   ±   5.5 kPa (versus 4.4   ±   1.6 kPa before ablation) in the chicken breast, to 30.3   ±   10.3 kPa (versus 12.2   ±   4.3 kPa) in the atria and to 73.8   ±   13.9 kPa (versus 21.2   ±   3.3 kPa) in the ventricles. On gross pathology, the size of the lesions ranged from 0.1 to 1.5 cm(2) in the imaging plane area. Elasticity-estimated depths and widths of the lesions differed respectively with a median of 0.2 mm (first quartile Q1:  -0.8 mm; third quartile Q3: 2.6 mm) for a mean squared error (MSE) of 5.1 mm(2) and a median of 0.2 mm (Q1:  -2.7 mm; Q3: 2.7 mm) for a MSE of 11.1 mm(2) from gross pathology. We have demonstrated the feasibility of the HIFU thermal ablation monitoring using a dual therapy and imaging transesophageal device. The combination of HIFU, ultrasound imaging and SWE on the same transesophageal system could lead to a new clinical device for a safer and controlled treatment of a wide variety of cardiac arrhythmias. |
10,299 | AFW extraction based on MCA. | This paper improves the learning dictionary construction method for morphological component analysis (MCA) to separate the atrial and ventricular signals. The incoherence is added into the objective function to reduce the sparsity ratio between the atrial and ventricular dictionaries. By using the dictionaries, atrial and ventricular activities are separated from the location of the coefficients. We test the methods on both the synthetic and real atrial data. While extracting AFW from synthetic data, we use the Poisson relation as the measure. The result shows that we can obtain greater relation value using the method this paper presents than using the methods of ABS and PCA. We also conduct spectral analysis on AFW extracted from real atrial data. |
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