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10,300 | Non-invasive cardiac mapping in clinical practice: Application to the ablation of cardiac arrhythmias. | Ten years ago, electrocardiographic imaging (ECGI) started to demonstrate its efficiency in clinical settings. The initial application to localize focal ventricular arrhythmias such as ventricular premature beats was probably the easiest to challenge and validates the concept. Our clinical experience in using this non-invasive mapping technique to identify the sources of electrical disorders and guide catheter ablation of atrial arrhythmias (premature atrial beat, atrial tachycardia, atrial fibrillation), ventricular arrhythmias (premature ventricular beats) and ventricular pre-excitation (Wolff-Parkinson-White syndrome) is described here. |
10,301 | Atrioventricular and ventricular-to-ventricular programming in patients with cardiac resynchronization therapy: results from ALTITUDE. | Cardiac resynchronization therapy (CRT) improves outcomes in patients with heart failure, yet response rates are variable. We sought to determine whether physician-specified CRT programming was associated with improved outcomes.</AbstractText>Using data from the ALTITUDE remote follow-up cohort, we examined sensed atrioventricular (AV) and ventricular-to-ventricular (VV) programming and their associated outcomes in patients with de novo CRT from 2009-2010. Outcomes included arrhythmia burden, left ventricular (LV) pacing, and all-cause mortality at 4 years.</AbstractText>We identified 5709 patients with de novo CRT devices; at the time of implant, 34% (n = 1959) had entirely nominal settings programmed, 40% (n = 2294) had only AV timing adjusted, 11% (n = 604) had only VV timing adjusted, and 15% (n = 852) had both AV and VV adjusted from nominal programming. Suboptimal LV pacing (<95%) during follow-up was similar across groups; however, the proportion with atrial fibrillation (AF) burden >5% was lowest in the AV-only adjusted group (17.9%) and highest in the nominal (27.7%) and VV-only adjusted (28.3%) groups. Adjusted all-cause mortality was significantly higher among patients with non-nominal AV delay >120 vs. <120 ms (adjusted heart rate (HR) 1.28, p = 0.008) but similar when using the 180-ms cutoff (adjusted HR 1.13 for >180 vs. ≤180 ms, p = 0.4).</AbstractText>Nominal settings for de novo CRT implants are frequently altered, most commonly the AV delay. There is wide variability in reprogramming. Patients with nominal or AV-only adjustments appear to have favorable pacing and arrhythmia outcomes. Sensed AV delays less than 120 ms are associated with improved survival.</AbstractText> |
10,302 | Outcomes and hospital admissions during long-term support with a HeartMate II. | Continuous-flow left ventricular assist devices like the HeartMate II (HMII) improves survival in severe heart failure but little is known about the incidence and causes of hospitalizations during long-term support which was evaluated in this study.</AbstractText>Observational follow-up study comprising all patients who received a HMII at our institution either as bridge-to-transplantation (BTT) or destination therapy (DT). All patients were followed from HMII implantation to transplantation, device explantation, death, or May 2015.</AbstractText>The HMII was implanted in 66(44 BTT, 22 DT) patients with a median (range) duration of support since implantation of 329(2-2707) days with 260(2-1080) days in the BTT group and 608(6-2707) days in the DT group. Thirty-day mortality was 12% and one-year survival 76%, comparable for DT and BTT. Among 56 (19 DT and 37 BTT) patients discharged alive with a HMII there were 161 hospital readmissions during a follow-up of 336(37-2682) days corresponding to a hospitalization rate of 1.3(0-19) per patient year and with a length of stay of 5(2-72) days per admission. Most frequent cause of readmission was infections (29%). A history of atrial fibrillation was the only independent factor associated with increased readmission rates.</AbstractText>Our single-center study demonstrated encouraging survival following HMII implantation. Hospital readmissions were frequent, mostly of short duration, mainly due to infections and increased in patients with atrial fibrillation.</AbstractText> |
10,303 | Kcne4 deletion sex- and age-specifically impairs cardiac repolarization in mice. | Myocardial repolarization capacity varies with sex, age, and pathology; the molecular basis for this variation is incompletely understood. Here, we show that the transcript for KCNE4, a voltage-gated potassium (Kv) channel β subunit associated with human atrial fibrillation, was 8-fold more highly expressed in the male left ventricle compared with females in young adult C57BL/6 mice (P < 0.05). Similarly, Kv current density was 25% greater in ventricular myocytes from young adult males (P < 0.05). Germ-line Kcne4 deletion eliminated the sex-specific Kv current disparity by diminishing ventricular fast transient outward current (Ito,f) and slowly activating K(+) current (IK,slow1). Kcne4 deletion also reduced Kv currents in male mouse atrial myocytes, by >45% (P < 0.001). As we previously found for Kv4.2 (which generates mouse Ito,f), heterologously expressed KCNE4 functionally regulated Kv1.5 (the Kv α subunit that generates IKslow1 in mice). Of note, in postmenopausal female mice, ventricular repolarization was impaired by Kcne4 deletion, and ventricular Kcne4 expression increased to match that of males. Moreover, castration diminished male ventricular Kcne4 expression 2.8-fold, whereas 5α-dihydrotestosterone (DHT) implants in castrated mice increased Kcne4 expression >3-fold (P = 0.01) to match noncastrated levels. KCNE4 is thereby shown to be a DHT-regulated determinant of cardiac excitability and a molecular substrate for sex- and age-dependent cardiac arrhythmogenesis. |
10,304 | MG132 proteasome inhibitor upregulates the expression of connexin 43 in rats with adriamycin-induced heart failure. | The connexin 43 (Cx43) gap junction protein is important in the synchronization of contraction of cardiac myocytes. Abnormal expression of Cx43 contributes to ventricular arrhythmia, which is the major cause of sudden death in heart failure (HF). Cx43 is known to interact with zonula occludens (ZO)‑1, and the proteasome is involved in the regulation of Cx43 degradation. Although Cx43 is downregulated in heart failure, the underlying mechanisms remain to be elucidated. The present study aimed to investigate the effect of the MG132 proteasome inhibitor on the expression levels of Cx43, ZO‑1, 20S proteasome and ubiquitin in a rat model of HF, induced by adriamycin. MG132 reduced adriamycin‑induced injury in the failing heart. In addition, MG132 inhibited the expression of 20S proteasome and ubiquitin, accompanied by an upregulation in the expression of Cx43 and ZO‑1. These findings suggested that inhibition of the ubiquitin‑proteasome system upregulated the expression of Cx43. Therefore, the proteasome inhibitor may be used to prevent degradation of Cx43 in HF, and thus may prevent Cx43-mediated arrhythmia in HF. |
10,305 | Nandrolone Plus Moderate Exercise Increases the Susceptibility to Lethal Arrhythmias. | Until now, no experimental study has directly assessed the arrhythmogenesis of chronic consumption of anabolic androgenic steroids along with moderate-intensity endurance exercise.</AbstractText>We evaluated the influence of integration of anabolic androgenic steroids along with moderate-intensity endurance exercise on susceptibility to lethal ventricular arrhythmias in rat.</AbstractText>The animal groups were as follows: control group (CTL); exercise group (EX) which were under 6 weeks of treadmill exercise; nandrolone group (Nan) which received 5 mg/kg of nandrolone decanoate twice a week; vehicle group (Arach) which received Arachis oil (solvent of nandrolone); trained vehicle group (Arach + Ex); and trained nandrolone group (Nan + Ex). One day after ending of the intervention period, arrhythmia was inducted by intravenous infusion of aconitine and ventricular arrhythmias were recorded. Then malondialdehyde (MDA) and glutathione peroxidase (GPX) of heart tissue were measured.</AbstractText>Nandrolone, exercise, and their combination were associated with heart hypertrophy. Exercise could prevent the incremental effect of nandrolone on MDA/GPX ratio. Chronic administration of nandrolone with moderate-intensity endurance exercise had no significant effect on blood pressure, heart rate, and basal electrocardiographic parameters. Combination of nandrolone and exercise significantly increased the incidence of ventricular fibrillation (VF) and reduced the VF latency (P < 0.05).</AbstractText>The findings suggest that chronic coadministration of nandrolone with moderate-intensity endurance exercise facilitates the VF occurrence in rat. Complementary studies are needed to elucidate the involved mechanisms of this abnormality.</AbstractText> |
10,306 | Findings From 12-lead Electrocardiography That Predict Circulatory Shock From Pulmonary Embolism: Systematic Review and Meta-analysis. | Treatment guidelines for acute pulmonary embolism (PE) recommend risk stratifying patients to assess PE severity, as those at higher risk should be considered for therapy in addition to standard anticoagulation to prevent right ventricular (RV) failure, which can cause hemodynamic collapse. The hypothesis was that 12-lead electrocardiography (ECG) can aid in this determination. The objective of this study was to measure the prognostic value of specific ECG findings (the Daniel score, which includes heart rate > 100 beats/min, presence of the S1Q3T3 pattern, incomplete and complete right bundle branch block [RBBB], and T-wave inversion in leads V1-V4, plus ST elevation in lead aVR and atrial fibrillation suggestive of RV strain from acute pulmonary hypertension), in patients with acute PE.</AbstractText>Studies were identified by a structured search of MEDLINE, PubMed, EMBASE, the Cochrane library, Google Scholar, Scopus, and bibliographies in October 2014. Case reports, non-English papers, and those that lacked either patient outcomes or ECG findings were excluded. Papers with evidence of a predefined reference standard for PE and the results of 12-lead ECG, stratified by outcome (hemodynamic collapse, defined as circulatory shock requiring vasopressors or mechanical ventilation, or in hospital or death within 30 days) were included. Papers were assessed for selection and publication bias. The authors also assessed heterogeneity (I(2) ) and calculated the odds ratios (OR) for each ECG sign from the random effects model if I(2) > 24% and fixed effects if I(2) < 25%. Funnel plots were used to examine for publication bias.</AbstractText>Forty-five full-length studies of 8,209 patients were analyzed. The most frequent ECG signs found in patients with acute PE were tachycardia (38%), T-wave inversion in lead V1 (38%), and ST elevation in lead aVR (36%). Ten studies with 3,007 patients were included for full analysis. Six ECG findings (heart rate > 100 beats/min, S1Q3T3, complete RBBB, inverted T waves in V1-V4, ST elevation in aVR, and atrial fibrillation) had likelihood and ORs with lower-limit 95% confidence intervals above unity, suggesting them to be significant predictors of hemodynamic collapse and 30-day mortality. OR data showed no evidence of publication bias, but the proportions of patients with hemodynamic collapse or death and S1Q3T3 and RBBB tended to be higher in smaller studies. Patients who were outcome-negative had a significantly lower mean ± SD Daniel score (2.6 ± 1.5) than patients with hemodynamic collapse (5.9 ± 3.9; p = 0.039, ANOVA with Dunnett's post hoc), but not patients with all-cause 30-day mortality (4.9 ± 3.3; p = 0.12).</AbstractText>This systematic review and meta-analysis revealed 10 studies, including 3,007 patients with acute PE, that demonstrate that six findings of RV strain on 12-lead ECG (heart rate > 100 beats/min, S1Q3T3, complete RBBB, inverted T waves in V1-V4, ST elevation in aVR, and atrial fibrillation) are associated with increased risk of circulatory shock and death.</AbstractText>© 2015 by the Society for Academic Emergency Medicine.</CopyrightInformation> |
10,307 | SCN5A variant that blocks fibroblast growth factor homologous factor regulation causes human arrhythmia. | Nav channels are essential for metazoan membrane depolarization, and Nav channel dysfunction is directly linked with epilepsy, ataxia, pain, arrhythmia, myotonia, and irritable bowel syndrome. Human Nav channelopathies are primarily caused by variants that directly affect Nav channel permeability or gating. However, a new class of human Nav channelopathies has emerged based on channel variants that alter regulation by intracellular signaling or cytoskeletal proteins. Fibroblast growth factor homologous factors (FHFs) are a family of intracellular signaling proteins linked with Nav channel regulation in neurons and myocytes. However, to date, there is surprisingly little evidence linking Nav channel gene variants with FHFs and human disease. Here, we provide, to our knowledge, the first evidence that mutations in SCN5A (encodes primary cardiac Nav channel Nav1.5) that alter FHF binding result in human cardiovascular disease. We describe a five*generation kindred with a history of atrial and ventricular arrhythmias, cardiac arrest, and sudden cardiac death. Affected family members harbor a novel SCN5A variant resulting in p.H1849R. p.H1849R is localized in the central binding core on Nav1.5 for FHFs. Consistent with these data, Nav1.5 p.H1849R affected interaction with FHFs. Further, electrophysiological analysis identified Nav1.5 p.H1849R as a gain-of-function for INa by altering steady-state inactivation and slowing the rate of Nav1.5 inactivation. In line with these data and consistent with human cardiac phenotypes, myocytes expressing Nav1.5 p.H1849R displayed prolonged action potential duration and arrhythmogenic afterdepolarizations. Together, these findings identify a previously unexplored mechanism for human Nav channelopathy based on altered Nav1.5 association with FHF proteins. |
10,308 | PULSE-SMART: Pulse-Based Arrhythmia Discrimination Using a Novel Smartphone Application. | Atrial fibrillation (AF) is a common and dangerous rhythm abnormality. Smartphones are increasingly used for mobile health applications by older patients at risk for AF and may be useful for AF screening.</AbstractText>To test whether an enhanced smartphone app for AF detection can discriminate between sinus rhythm (SR), AF, premature atrial contractions (PACs), and premature ventricular contractions (PVCs).</AbstractText>We analyzed two hundred and nineteen 2-minute pulse recordings from 121 participants with AF (n = 98), PACs (n = 15), or PVCs (n = 15) using an iPhone 4S. We obtained pulsatile time series recordings in 91 participants after successful cardioversion to sinus rhythm from preexisting AF. The PULSE-SMART app conducted pulse analysis using 3 methods (Root Mean Square of Successive RR Differences; Shannon Entropy; Poincare plot). We examined the sensitivity, specificity, and predictive accuracy of the app for AF, PAC, and PVC discrimination from sinus rhythm using the 12-lead EKG or 3-lead telemetry as the gold standard. We also administered a brief usability questionnaire to a subgroup (n = 65) of app users.</AbstractText>The smartphone-based app demonstrated excellent sensitivity (0.970), specificity (0.935), and accuracy (0.951) for real-time identification of an irregular pulse during AF. The app also showed good accuracy for PAC (0.955) and PVC discrimination (0.960). The vast majority of surveyed app users (83%) reported that it was "useful" and "not complex" to use.</AbstractText>A smartphone app can accurately discriminate pulse recordings during AF from sinus rhythm, PACs, and PVCs.</AbstractText>© 2015 Wiley Periodicals, Inc.</CopyrightInformation> |
10,309 | Apolipoprotein-J prevents angiotensin II-induced apoptosis in neonatal rat ventricular cells. | Up-regulation of angiotensin II (AngII) occurs in cardiac diseases, such as congestive heart failure, cardiac hypertrophy, myocardial ischemia and atrial fibrillation, which represent major health problems. Evidence from in vivo studies suggests that the level of Apolipoprotein-J (ApoJ) is also elevated but plays a protective role in cardiovascular disease. This study aimed to evaluate the protective effects of ApoJ against cytotoxicity of AngII in neonatal rat ventricular cells (NRVCs).</AbstractText>In culture, NRVCs were damaged by exposure to AngII, and ApoJ overexpression using an adenovirus vector significantly reduced the AngII-induced cell injury. ApoJ also prevented AngII from augmenting Nox2/gp91(phox) expression. The reactive oxygen species (ROS) scavenger, Mn(III)TBAP, showed similar results of attenuating AngII-induced cell damage. Furthermore, ApoJ overexpression increased phosphorylation of Akt, and the phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002 diminished the antioxidant effects of ApoJ, and prevented the protective effect of ApoJ against the cytotoxicity of AngII. Moreover, upregulation of nuclear factor κB (NF-κB) p65 expression and phosphorylation of p38 mitogen-activated protein kinase (MAPK) mediated by AngII in cultured NRVCs were significantly inhibited by overexpression of ApoJ. The p38 MAPK inhibitor SB203580 and the NF-κB inhibitor PDTC protected NRVCs from injury caused by AngII.</AbstractText>ApoJ serves as a cytoprotective protein in NRVCs against cytotoxicity of AngII through the PI3K-Akt-ROS and MAPK/ NF-κB pathways.</AbstractText> |
10,310 | Should β-blockers be used in patients with heart failure and atrial fibrillation? | There is overwhelming evidence that β-blockers reduce cardiovascular hospitalizations and mortality in patients with heart failure and a reduced left ventricular ejection fraction provide they are in sinus rhythm. However, a recent meta-analysis of individual patient data provides compelling evidence that β-blockers are not effective in patients with heart failure and atrial fibrillation, although neither did they increase risk. The purpose of this article is to review the evidence, seek possible explanations for this observation, and make recommendations based on the limited evidence available.</AbstractText>Review and critical analysis of recent publications and meta-analyses on the use of β-blockers and other heart rate-slowing medicines in heart failure.</AbstractText>The reasons for the lack of effect of β-blockers in patients with heart failure are uncertain. There is a substantial body of evidence to suggest that patients with heart failure and atrial fibrillation who have less stringent ventricular rate control have a better outcome. The most plausible explanation for these findings, in our view, is that β-blockers exert similar benefits through similar mechanisms regardless of intrinsic heart rhythm but that the benefits of β-blockers are neutralized in patients with atrial fibrillation due to the induction of pauses that may impair cardiac function leading to worsening heart failure or cause arrhythmias resulting in death.</AbstractText>Smaller doses of β-blockers and other rate lowering agents to achieve a resting clinic heart rate in the range of 75-89beats/min might improve outcome. Preventing pauses by pacing or pulmonary vein ablation of atrial fibrillation are strategies that should be researched.</AbstractText>Copyright © 2015 Elsevier HS Journals, Inc. All rights reserved.</CopyrightInformation> |
10,311 | You're the Flight Surgeon. Arrythmogenic right ventricular cardiomyopathy. | Duong A. You're the flight surgeon: arrythmogenic right ventricular cardiomyopathy. Aerosp Med Hum Perform. 2015; 86(8):756-759. |
10,312 | Greater temperature variability is not associated with a worse neurological outcome after cardiac arrest. | Spontaneous alterations in temperature homeostasis after cardiac arrest (CA) are associated with worse outcome. However, it remains unclear the prognostic role of temperature variability (TV) during cooling procedures. We hypothesized that low TV during targeted temperature management (TTM) would be associated with a favourable neurological outcome after CA.</AbstractText>We reviewed data from all comatose patients after in-hospital or out-of-hospital CA admitted to our Department of Intensive Care between December 2006 and January 2014 who underwent TTM (32-34°C) and survived at least 24h. We collected demographic data, CA characteristics, intensive care unit (ICU) survival and neurological outcome at three months (favourable neurological outcome was defined as cerebral performance category 1-2). TV was expressed using the standard deviation (SD) of all temperature measurements during hypothermia; high TV was defined as an SD >1°C.</AbstractText>Of the 301 patients admitted over the study period, 72 patients were excluded and a total of 229 patients were studied; 88 had a favourable neurological outcome. The median temperature on ICU admission was 35.8 [34.9-36.9]°C and the median time to hypothermia (body temperature <34°C), was 4 [3-7] h. Median TV was 0.9 [0.6-1.0]°C and 57 patients (25%) had high TV. In multivariable logistic regression, witnessed CA, ventricular fibrillation/tachycardia and previous neurological disease were independent risk factors for high TV. Younger age, bystander cardiopulmonary resuscitation, shorter time to return of spontaneous circulation, cardiac origin of arrest, shockable rhythm and longer time to target temperature were independent predictors of favourable neurological outcome, but TV was not.</AbstractText>Among comatose survivors treated with TTM after CA, 25% of patients had high TV; however, this was not associated with a worse neurologic outcome.</AbstractText>Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
10,313 | Contact Force in Atrial Fibrillation: Role of Atrial Rhythm and Ventricular Contractions: Co-Force Atrial Fibrillation Study. | In an experimental model, variable and intermittent contact force (CF) resulted in a significant decrease in lesion volume. In humans, variability of CF during pulmonary vein isolation has not been characterized.</AbstractText>In 20 consecutive patients undergoing CF-guided circumferential pulmonary vein isolation, 914 radiofrequency applications (530 in sinus rhythm and 384 in atrial fibrillation) were analyzed. The variability of the 60% CF range (CF(60%)) was 17±9.6 g. Hundred seventy-one (19%) applications were delivered with constant, 717 (78%) with variable, and 26 (3%) with intermittent CF. The mean CF and force-time integral were significantly higher during applications with variable than with intermittent or constant CF. There was no significant difference in CF variability, CF(60%) variability, and force-time integral between applications delivered in sinus rhythm and atrial fibrillation. The main reasons for CF variability were systolo-diastolic heart movement (29%) and respiration (27%). In 10 additional patients, during adenosine-induced atrioventricular block, the minimum CF significantly increased at 19 sites (5.3±4.4 versus 13.4±5.9 g; P<0.001) and at 16 sites intermittent or variable CF became constant. At only 1 site systolo-diastolic movement remained the main reason for variable CF.</AbstractText>CF during pulmonary vein isolation remains highly variable despite efforts to optimize contact. CF and CF parameters were similar during sinus rhythm and atrial fibrillation. The main reasons for CF variability are systolo-diastolic heart movement and respiration. The systolo-diastolic peaks and nadirs of CF are because of ventricular contractions at the large majority of pulmonary vein isolation sites.</AbstractText>© 2015 American Heart Association, Inc.</CopyrightInformation> |
10,314 | Minor Variations in Electrode Pad Placement Impact Defibrillation Success. | Defibrillation is essential for resuscitating patients with ventricular fibrillation (VF), but shocks often fail to defibrillate. We hypothesized that small variations in pad placement affect shock success, and that defibrillation waveform and shock dose could compensate for suboptimal pad placement. In 10 swine experiments, electrode pads were attached at 3 adjacent anterolateral positions, less than 3 centimeters apart. At each position, 24 episodes of VF were induced and shocked, 8 episodes for each of 3 defibrillation therapies. This resulted in 9 tested combinations of pad position and defibrillation therapy, with 80 episodes of VF for each combination. An episode consisted of 15 seconds of untreated VF, followed by a first shock and, if necessary, a repeat shock. Episodes were separated by four minutes of recovery. Both electrode pad position and therapy order were randomized by experiment. Primary outcome was defined as successful VF termination after the first shock; secondary outcome was the cumulative success of the first and second shocks. First shock efficacy varied widely across the 9 tested combinations of pad position and defibrillation therapy, ranging from 11.3% to 86.3%. When grouped by therapy, first shock efficacy varied significantly between the 3 pad positions: 38.3%, 48.3%, 36.7% (p = 0.02, ANOVA), and, when grouped by pad position, it varied significantly between therapies: 15.0%, 32.5%, 75.8% (p < 0.001, ANOVA). Cumulative 2-shock success varied significantly with therapy (p < 0.001, ANOVA) but not with pad position (p = 0.30, ANOVA). The lowest first shock success was at one position in 6 of 10 animals, at another position in 4 of 10 animals, and never at the third position. Small variations in pad placement can significantly affect defibrillation shock efficacy. However, anatomical variation between individuals and the challenging conditions of real-world resuscitations make optimal pad placement impractical. Suboptimal pad placement can be overcome with defibrillation waveform and shock dose. |
10,315 | The proposed new classification of coronary microcirculation as the predictor of the heart failure progression in idiopathic dilated cardiomyopathy. | The appropriate condition of the coronary microcirculation is essential for proper cardiac muscle activity. The understanding of the pathological microcirculation changes in different stages of idiopathic dilated cardiomyopathy (IDCM) could provide a reliable background for proper therapeutic decisions and prognosis.</AbstractText>The study population consisted of 116 patients (86.2% males, mean age 50.4±13.2 years) with IDCM and heart failure. In samples from left ventricular endomyocardial biopsy, the coronary microcirculation was evaluated by staining with hematoxylin and eosin, Masson's trichrome, and anti-CD34 antibody. The microvessel density (MVD) was calculated. Also, the electron microscopic evaluation of the extracellular matrix capillaries was performed. Samples were assigned to one of four types according to the microcirculation condition: 1, normal microvessels (MVs) (18 patients); 2, mostly normal, some MVs with slightly decreased lumen diameter and thickened wall, absent/mild intravascular fibrosis, and MVD decrease (37 patients); 3, MVs with moderately decreased lumen diameter and thickened wall, moderate intravascular fibrosis, and MVD decrease (45 patients); and 4, MVs with significantly decreased lumen diameter and thickened wall, significant intravascular fibrosis, and MVD decrease (16 patients). Taking all types of the proposed classification into consideration, in type 4, clinical (incidence of New York Heart Association 3 and 4, dyspnea on exertion, pulmonary congestion) and echocardiographic (left atrial and right ventricular diameter, left ventricular mass and ejection fraction, tricuspid annular plane systolic excursion, early diastolic mitral annular velocity measured at the interventricular-septal annulus [E'med], ratio of early diastolic mitral inflow velocity to E'med) parameters were worst. Only atrial fibrillation, diabetes, tricuspid annular plane systolic excursion, and the type of the microcirculation significantly correlated with the incidence of cardiovascular hospitalizations in the linear regression models.</AbstractText>The condition of the coronary microcirculation corresponds with the heart failure progression in patients with IDCM.</AbstractText>Copyright © 2015 Elsevier Inc. All rights reserved.</CopyrightInformation> |
10,316 | Transhepatic venous approach to permanent pacemaker placement in a patient with limited central venous access. | The end-stage renal disease population poses a challenge for obtaining venous access required for life-saving invasive cardiac procedures. In this case report, we describe an adult patient with end-stage renal disease in whom the hepatic vein was the only available access to implant a single-lead permanent cardiac pacemaker. A 63-year-old male with end-stage renal disease on maintenance hemodialysis and permanent atrial fibrillation/atrial flutter presented with symptomatic bradycardia. Imaging studies revealed all traditional central venous access sites to be occluded/non-accessible. With the assistance of vascular interventional radiology, a trans-hepatic venous catheter was placed. This was then used to place a right ventricular pacing lead with close attention to numerous technical aspects. The procedure was completed successfully with placement of a single-lead permanent cardiac pacemaker. |
10,317 | [Successful termination of ventricular fibrillation using the precordial thump]. | A 75 year old female underwent angiography which revealed diffuse restenosis in a bare metal stent implanted in the right coronary artery, three month earlier. A wire was used to cross the lesion; balloon angioplasty was performed followed by drug eluting stent implantation. Inflation times were short. As the balloon of the stent was retrieved, the patient went into ventricular fibrillation (VF). An order to charge the defibrillator for DC shock was given. The operating physician immediately delivered a quick strong blow to the patient's thorax (precordial thump) which stopped the VF rhythm and converted it into atrial fibrillation. The patient regained consciousness and had no recollection of what had happened. No DC shock was needed. |
10,318 | Fever and Cardiac Arrest in a Patient With a Left Ventricular Assist Device. | A 68-year-old avid deer hunter with ischemic cardiomyopathy underwent left ventricular assist device (LVAD) implantation for destination therapy two years ago. He was living an active lifestyle, tracking deer and fishing in a Midwestern forest in November. His wife removed an engorged tick on his thorax. A few days later, he experienced fever, confusion, and ataxia and was hospitalized with septic shock and ventricular fibrillation. The LVAD site had no signs of trauma, drainage, warmth, or tenderness. A peripheral blood smear revealed intraleukocytic anaplasma microcolony inclusions. After completing 14 days of doxycycline, he recovered. Typical non-device-associated infections in LVAD recipients include pneumonia, urinary tract infection, or Clostridium difficile colitis. Human granulocytic anaplasmosis (HGA) is a very atypical non-LVAD infection, and the incidence of tickborne illnesses in LVAD recipients is unknown. |
10,319 | In-hospital clinical outcomes of elderly patients (≥60 years) undergoing primary percutaneous coronary intervention. | Elderly patients are at high risk of mortality when they present with ST-elevation myocardial infarction (STEMI). However, the clinical outcomes of this sub-group undergoing primary percutaneous coronary intervention (PPCI) have not been well established, despite recent advances in both devices and techniques. In the present retrospective cohort study from a Chinese single center, we assessed the clinical outcomes and predictors of mortality in elderly patients (≥60 years) underwent with PPCI. The primary endpoints were immediate angiographic success and in-hospital procedural success. The secondary endpoints were all-cause death in hospital. Between January 2011 and December 2013, a total of 184 consecutive patients with acute STEMI underwent PPCI were enrolled. 116 (63.04%) patients were in the elderly group. Despite the difference in lesion complexity between groups, the immediate angiographic success rate was similar (93.97% in the elderly group, and 94.12% in the non-elderly group, P=0.966). The procedural success rate were not significantly different between the two groups (90.52% in the elderly group, and 94.12% in the non-elderly group, P=0.389). However, in-hospital mortality was statistically higher in elderly group than in the non-elderly group (8.62% Vs 1.47%, P=0.048). The major causes of death were cardiac shock and malignant arrhythmias (ventricular tachycardia and fibrillation). Our results indicate that PPCI in the elderly is feasible and has a high likelihood of immediate angiographic and procedural success. |
10,320 | Exercise capacity and muscle strength and risk of vascular disease and arrhythmia in 1.1 million young Swedish men: cohort study. | To investigate the associations of exercise capacity and muscle strength in late adolescence with risk of vascular disease and arrhythmia.</AbstractText>Cohort study.</AbstractText>General population in Sweden.</AbstractText>1.1 million men who participated in mandatory military conscription between 1 August 1972 and 31 December 1995, at a median age of 18.2 years. Participants were followed until 31 December 2010.</AbstractText>Associations between exercise capacity and muscle strength with risk of vascular disease and subgroups (ischaemic heart disease, heart failure, stroke, and cardiovascular death) and risk of arrhythmia and subgroups (atrial fibrillation or flutter, bradyarrhythmia, supraventricular tachycardia, and ventricular arrhythmia or sudden cardiac death). Maximum exercise capacity was estimated by the ergometer bicycle test, and muscle strength was measured as handgrip strength by a hand dynamometer. High exercise capacity or muscle strength was deemed as above the median level.</AbstractText>During a median follow-up of 26.3 years, 26 088 vascular disease events and 17 312 arrhythmia events were recorded. Exercise capacity was inversely associated with risk of vascular disease and its subgroups. Muscle strength was also inversely associated with vascular disease risk, driven by associations of higher muscle strength with lower risk of heart failure and cardiovascular death. Exercise capacity had a U shaped association with risk of arrhythmia, driven by a direct association with risk of atrial fibrillation and a U shaped association with bradyarrhythmia. Higher muscle strength was associated with lower risk of arrhythmia (specifically, lower risk of bradyarrhythmia and ventricular arrhythmia). The combination of high exercise capacity and high muscle strength was associated with a hazard ratio of 0.67 (95% confidence interval 0.65 to 0.70) for vascular events and 0.92 (0.88 to 0.97) for arrhythmia compared with the combination of low exercise capacity and low muscle strength.</AbstractText>Exercise capacity and muscle strength in late adolescence are independently and jointly associated with long term risk of vascular disease and arrhythmia. The health benefit of lower risk of vascular events with higher exercise capacity was not outweighed by higher risk of arrhythmia.</AbstractText>© Andersen et al 2015.</CopyrightInformation> |
10,321 | Contractile function assessment by intraventricular balloon alters the ability of regional ischaemia to evoke ventricular fibrillation. | In drug research using the rat Langendorff heart preparation, it is possible to study left ventricular (LV) contractility using an intraventricular balloon (IVB), and arrhythmogenesis during coronary ligation-induced regional ischaemia. Assessing both concurrently would halve animal requirements. We aimed to test the validity of this approach.</AbstractText>The electrocardiogram (ECG) and LV function (IVB) were recorded during regional ischaemia of different extents in a randomized and blinded study.</AbstractText>IVB-induced proarrhythmia was anticipated, but in hearts with an ischaemic zone (IZ) made deliberately small, an inflated IVB reduced ischaemia-induced ventricular fibrillation (VF) incidence as a trend. Repeating studies in hearts with large IZs revealed the effect to be significant. There were no changes in QT interval or other variables that might explain the effect. Insertion of an IVB that was minimally inflated had no effect on any variable compared with 'no IVB' controls. The antiarrhythmic effect of verapamil (a positive control drug) was unaffected by IVB inflation. Removal of an inflated (but not a non-inflated) IVB caused a release of lactate commensurate with reperfusion of an endocardial/subendocardial layer of IVB-induced ischaemia. This was confirmed by intracellular (31) phosphorus ((31) P) nuclear magnetic resonance (NMR) spectroscopy.</AbstractText>IVB inflation does not inhibit VF suppression by a standard drug, but it has profound antiarrhythmic effects of its own, likely to be due to inflation-induced localized ischaemia. This means rhythm and contractility cannot be assessed concurrently by this approach, with implications for drug discovery and safety assessment.</AbstractText>© 2015 The British Pharmacological Society.</CopyrightInformation> |
10,322 | Prevalence, Patterns, and Clinical Predictors of Left Ventricular Late Gadolinium Enhancement in Patients Undergoing Cardiac Magnetic Resonance Prior to Pulmonary Vein Antral Isolation for Atrial Fibrillation: A Cross-Sectional Observational Study. | Cardiac magnetic resonance (CMR) imaging is increasingly used to evaluate patients with atrial fibrillation (AF) before pulmonary vein antral isolation (PVAI). The purpose of this study was to assess the incidence and pattern of left ventricular (LV) late gadolinium enhancement (LGE) in patients undergoing CMR before PVAI and compare the clinical and demographic differences of patients with and without LV LGE. Clinical and demographic data on 62 patients (mean age 61 ± 7.9, 69% male) undergoing CMR before PVAI for AF were collected. Two observers, masked to clinical histories, independently recorded the prevalence, extent (number of myocardial segments), and pattern (subendocardial, midmyocardial, or subepicardial) of LV LGE in each patient. Clinical and demographic predictors of LV LGE were determined using logistic regression. Twenty-three patients (37%) demonstrated LV LGE affecting a mean of 3.0 ± 2.1 myocardial segments. There was no difference in LV ejection fraction between patients with and without LGE, and most (65%) patients with LGE had normal wall motion. Only age (P = 0.04) and a history of congestive heart failure (P = .03) were statistically significant independent predictors of LGE. The most common LGE pattern was midmyocardial, seen in 17 of 23 (74%) patients. Only 4 of 23 (17%) patients had LGE in an "expected" pattern based on clinical history. Of the remaining 19 patients, 4 had known congestive heart failure, 5 nonischemic cardiomyopathy, 4 known coronary artery disease, and 2 prior aortic valve replacement. Six of 23 (26%) patients had no known coronary artery, valvular, or myocardial disease. There is a high prevalence of unexpected LV scar in patients undergoing CMR before PVAI for AF, with most patients demonstrating a nonischemic pattern of LV LGE and no wall motion abnormalities (ie, subclinical disease). The high prevalence of unexpected LGE in these patients may argue for CMR as the modality of choice for imaging integration before PVAI, especially given the demonstrated prognostic value of LGE in this and other patient populations. |
10,323 | The impact of a pre-hospital critical care team on survival from out-of-hospital cardiac arrest. | To assess the impact of a pre-hospital critical care team (CCT) on survival from out-of-hospital cardiac arrest (OHCA).</AbstractText>We undertook a retrospective observational study, comparing OHCA patients attended by advanced life support (ALS) paramedics with OHCA patients attended by ALS paramedics and a CCT between April 2011 and April 2013 in a single ambulance service in Southwest England. We used multiple logistic regression to control for an anticipated imbalance of prognostic factors between the groups. The primary outcome was survival to hospital discharge. All data were collected independently of the research.</AbstractText>1851 cases of OHCA were included in the analysis, of which 1686 received ALS paramedic treatment and 165 were attended by both ALS paramedics and a CCT. Unadjusted rates of survival to hospital discharge were significantly higher in the CCT group, compared to the ALS paramedic group (15.8% and 6.5%, respectively, p<0.001). After adjustment using multiple logistic regression, the effect of CCT treatment was no longer statistically significant (OR 1.54, 95% CI 0.89-2.67, p=0.13). Subgroup analysis of OHCA with first monitored rhythm of ventricular fibrillation or pulseless ventricular tachycardia showed similar results.</AbstractText>Pre-hospital critical care for OHCA was not associated with significantly improved rates of survival to hospital discharge. These results are in keeping with previously published studies. Further research with a larger sample size is required to determine whether CCTs can improve outcome in OHCA.</AbstractText>Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
10,324 | Persistently Altered Brain Mitochondrial Bioenergetics After Apparently Successful Resuscitation From Cardiac Arrest. | Although advances in cardiopulmonary resuscitation have improved survival from cardiac arrest (CA), neurologic injury persists and impaired mitochondrial bioenergetics may be critical for targeted neuroresuscitation. The authors sought to determine if excellent cardiopulmonary resuscitation and postresuscitation care and good traditional survival rates result in persistently disordered cerebral mitochondrial bioenergetics in a porcine pediatric model of asphyxia-associated ventricular fibrillation CA.</AbstractText>After 7 minutes of asphyxia, followed by ventricular fibrillation, 5 female 1-month-old swine (4 sham) received blood pressure-targeted care: titration of compression depth to systolic blood pressure of 90 mm Hg and vasopressor administration to a coronary perfusion pressure >20 mm Hg. All animals received protocol-based vasopressor support after return of spontaneous circulation for 4 hours before they were killed. The primary outcome was integrated mitochondrial electron transport system (ETS) function. CA animals displayed significantly decreased maximal, coupled oxidative phosphorylating respiration (OXPHOSCI + CII) in cortex (P<0.02) and hippocampus (P<0.02), as well as decreased phosphorylation and coupling efficiency (cortex, P<0.05; hippocampus, P<0.05). Complex I- and complex II-driven respiration were both significantly decreased after CA (cortex: OXPHOSCI P<0.01, ETSCII P<0.05; hippocampus: OXPHOSCI P<0.03, ETSCII P<0.01). In the hippocampus, there was a significant decrease in maximal uncoupled, nonphosphorylating respiration (ETSCI + CII), as well as a 30% reduction in citrate synthase activity (P<0.04).</AbstractText>Mitochondria in both the cortex and hippocampus displayed significant alterations in respiratory function after CA despite excellent cardiopulmonary resuscitation and postresuscitation care in asphyxia-associated ventricular fibrillation CA. Analysis of integrated ETS function identifies mitochondrial bioenergetic failure as a target for goal-directed neuroresuscitation after CA. IACUC Protocol: IAC 13-001023.</AbstractText>© 2015 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.</CopyrightInformation> |
10,325 | Increased Heart Rate Is Associated With Higher Mortality in Patients With Atrial Fibrillation (AF): Results From the Outcomes Registry for Better Informed Treatment of AF (ORBIT-AF). | Most patients with atrial fibrillation (AF) require rate control; however, the optimal target heart rate remains under debate. We aimed to assess rate control and subsequent outcomes among patients with permanent AF.</AbstractText>We studied 2812 US outpatients with permanent AF in the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation. Resting heart rate was measured longitudinally and used as a time-dependent covariate in multivariable Cox models of all-cause and cause-specific mortality during a median follow-up of 24 months. At baseline, 7.4% (n=207) had resting heart rate <60 beats per minute (bpm), 62% (n=1755) 60 to 79 bpm, 29% (n=817) 80 to 109 bpm, and 1.2% (n=33) ≥110 bpm. Groups did not differ by age, previous cerebrovascular disease, heart failure status, CHA2DS2-VASc scores, renal function, or left ventricular function. There were significant differences in race (P=0.001), sinus node dysfunction (P=0.004), and treatment with calcium-channel blockers (P=0.006) and anticoagulation (P=0.009). In analyses of continuous heart rates, lower heart rate ≤65 bpm was associated with higher all-cause mortality (adjusted hazard ratio [HR], 1.15 per 5-bpm decrease; 95% CI, 1.01 to 1.32; P=0.04). Similarly, increasing heart rate >65 bpm was associated with higher all-cause mortality (adjusted HR, 1.10 per 5-bpm increase; 95% CI, 1.05 to 1.15; P<0.0001). This relationship was consistent across endpoints and in a broader sensitivity analysis of permanent and nonpermanent AF patients.</AbstractText>Among patients with permanent AF, there is a J-shaped relationship between heart rate and mortality. These data support current guideline recommendations, and clinical trials are warranted to determine optimal rate control.</AbstractText>URL: http://clinicaltrials.gov/. Unique identifier: NCT01165710.</AbstractText>© 2015 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.</CopyrightInformation> |
10,326 | An Experience of Landiolol Use for an Advanced Heart Failure Patient With Severe Hypotension. | Tachyarrhythmias such as atrial fibrillation (AF) or atrial flutter (AFL) sometimes invoke life-threatening collapse of hemodynamics in patients with severe heart failure. Recently, landiolol, an ultra-short acting β1-selective antagonist, has been reported to be safe and useful for the treatment of supraventricular tachyarrhythmias with reduced left ventricular function. Here we report a case of advanced heart failure with severe hypotension who was treated successfully by landiolol for rapid AF. The patient was a 20-year old male with dilated cardiomyopathy. He presented with low output syndrome in spite of optimal medical therapy and was referred to our department to consider ventricular assist device implantation and heart transplantation. Soon after admission, he developed rapid atrial fibrillation at 180 beats per minute (bpm) followed by severe hypotension and liver enzyme elevation. Low dose landiolol at 2 μg/kg/minute was started because digoxin was not effective. After landiolol administration, his heart rate decreased to 110 bpm, and finally returned to sinus rhythm without hemodynamic deterioration. Intra-aortic balloon pumping was inserted soon after sinus recovery and he was discharged successfully with an implantable left ventricular assist device. |
10,327 | Effective Management of Atrioventricular Interval for Paroxysmal Atrial Fibrillation That Developed After DDDR Pacemaker Implantation in a Sick Sinus Syndrome Patient. | A 68-year-old man with sick sinus syndrome (SSS) was referred to our department for pacemaker implantation. After implantation of a pacemaker with rate-responsive dual chamber (DDDR) mode and minimized ventricular pacing (MVP) functions, paroxysmal atrial fibrillation (PAF) repeatedly developed. Pacemaker memory showed that the intrinsic atrioventricular (AV) (atrial pacing-ventricular sensing [Ap-Vs]) interval was paradoxically prolonged during rate-responsive atrial single-chamber (AAIR) mode rapid pacing because of MVP. Accordingly, to eliminate the paradoxical prolongation of the AV interval during rapid atrial pacing, we changed MVP to medium AV hysteresis and conducted DDDR mode pacing with rate-dependent AV delay. PAF then sharply decreased without antiarrhythmic drugs. |
10,328 | Inhaled nitric oxide improves transpulmonary blood flow and clinical outcomes after prolonged cardiac arrest: a large animal study. | The probability to achieve a return of spontaneous circulation (ROSC) after cardiac arrest can be improved by optimizing circulation during cardiopulomonary resuscitation using a percutaneous left ventricular assist device (iCPR). Inhaled nitric oxide may facilitate transpulmonary blood flow during iCPR and may therefore improve organ perfusion and outcome.</AbstractText>Ventricular fibrillation was electrically induced in 20 anesthetized male pigs. Animals were left untreated for 10 minutes before iCPR was attempted. Subjects received either 20 ppm of inhaled nitric oxide (iNO, n = 10) or 0 ppm iNO (Control, n = 10), simultaneously started with iCPR until 5 hours following ROSC. Animals were weaned from the respirator and followed up for five days using overall performance categories (OPC) and a spatial memory task. On day six, all animals were anesthetized again, and brains were harvested for neurohistopathologic evaluation.</AbstractText>All animals in both groups achieved ROSC. Administration of iNO markedly increased iCPR flow during CPR (iNO: 1.81 ± 0.30 vs</AbstractText>1.64 ± 0.51 L/min, p < 0.001), leading to significantly higher coronary perfusion pressure (CPP) during the 6 minutes of CPR (25 ± 13 vs 16 ± 6 mmHg, p = 0.002). iNO-treated animals showed significantly lower S-100 serum levels thirty minutes post ROSC (0.26 ± 0.09 vs 0.38 ± 0.15 ng/mL, p = 0.048), as well as lower blood glucose levels 120-360 minutes following ROSC. Lower S-100 serum levels were reflected by superior clinical outcome of iNO-treated animals as estimated with OPC (3 ± 2 vs. 5 ± 1, p = 0.036 on days 3 to 5). Three out of ten iNO-treated, but none of the CONTROL animals were able to successfully participate in the spatial memory task. Neurohistopathological examination of vulnerable cerebral structures revealed a trend towards less cerebral lesions in neocortex, archicortex, and striatum in iNO-treated animals compared to CONTROLs.</AbstractText>In pigs resuscitated with mechanically-assisted CPR from prolonged cardiac arrest, the administration of 20 ppm iNO during and following iCPR improved transpulmonary blood flow, leading to improved clinical neurological outcomes.</AbstractText> |
10,329 | Non-invasive focus localization, right ventricular epicardial potential mapping in patients with an MRI-conditional pacemaker system - a pilot study. | With the advent of magnetic resonance imaging (MRI) conditional pacemaker systems, the possibility of performing MRI in pacemaker patients has been introduced. Besides for the detailed evaluation of atrial and ventricular volumes and function, MRI can be used in combination with body surface potential mapping (BSPM) in a non-invasive inverse potential mapping (IPM) strategy. In non-invasive IPM, epicardial potentials are reconstructed from recorded body surface potentials (BSP). In order to investigate whether an IPM method with a limited number of electrodes could be used for the purpose of non-invasive focus localization, it was applied in patients with implanted pacing devices. Ventricular paced beats were used to simulate ventricular ectopic foci.</AbstractText>Ten patients with an MRI-conditional pacemaker system and a structurally normal heart were studied. Patient-specific 3D thorax volume models were reconstructed from the MRI images. BSP were recorded during ventricular pacing. Epicardial potentials were inversely calculated from the BSP. The site of epicardial breakthrough was compared to the position of the ventricular lead tip on MRI and the distance between these points was determined.</AbstractText>For all patients, the site of earliest epicardial depolarization could be identified. When the tip of the pacing lead was implanted in vicinity to the epicardium, i.e. right ventricular (RV) apex or RV outflow tract, the distance between lead tip position and epicardial breakthrough was 6.0 ± 1.9 mm.</AbstractText>In conclusion, the combined MRI and IPM method is clinically applicable and can identify sites of earliest depolarization with a clinically useful accuracy.</AbstractText> |
10,330 | ECG signatures of psychological stress. | Psychological stress can lead to atrial and ventricular arrhythmias, but the physiological pathways have not been fully elucidated. Signal processing techniques can provide insight into electrophysiological mechanisms of stress-induced arrhythmia. T-wave alternans, as well as other ECG measures of heterogeneity of repolarization, increases with emotional and cognitive stress in the laboratory setting, and may also in "real life" settings. In the atrium, stress impacts components of the signal-averaged ECG. These changes suggest mechanisms by which everyday stressors can lead to arrhythmia. |
10,331 | ECG changes on continuous telemetry preceding in-hospital cardiac arrests. | About 200,000 patients suffer from in-hospital cardiac arrest (IHCA) annually. Identification of at-risk patients is key to improving outcomes. The use of continuous ECG monitoring in identifying patients at risk for developing IHCA has not been studied.</AbstractText>To describe the profile and timing of ECG changes prior to IHCA.</AbstractText>Retrospective, observational.</AbstractText>Single 520-bed tertiary care hospital.</AbstractText>IHCA in adults between April 2010 and March 2012 with at least 3 hours of continuous telemetry data immediately prior to IHCA.</AbstractText>We evaluated up to 24 hours of telemetry data preceding IHCA for changes in PR, QRS, ST segment, arrhythmias, and QTc in ventricular tachycardia cases. We determined mechanism and likely clinical cause of the arrest by chart and telemetry review.</AbstractText>We studied 81 IHCA patients, in whom the mechanism was ventricular tachycardia/fibrillation in 14 (18%), bradyasystolic in 21 (26%), and pulseless electrical activity (PEA) in 46 (56%). Preceding ECG changes were ST segment changes (31% of cases), atrial tachyarrhythmias (21%), bradyarrhythmias (28%), P wave axis change (21%),QRS prolongation (19%), PR prolongation (17%), isorhythmic dissociation (14%), nonsustained ventricular tachycardia (6%), and PR shortening (5%). At least one of these was present in 77% of all cases, and in 89% of IHCA caused by respiratory or multiorgan failure. Bradyarrhythmias were primarily seen with IHCA in the setting of respiratory or multiorgan failure, and PR and QRS prolongation with IHCA and concomitant multiorgan failure.</AbstractText>This is a retrospective study with a limited number of cases; each patient serves as their own control, and a separate control population has not yet been studied.</AbstractText>ECG changes are commonly seen preceding IHCA, and have a pathophysiologic basis. Automated detection methods for ECG changes could potentially be used to better identify patients at risk for IHCA.</AbstractText>Copyright © 2015 Elsevier Inc. All rights reserved.</CopyrightInformation> |
10,332 | Small-Conductance Calcium-Activated Potassium Current Is Activated During Hypokalemia and Masks Short-Term Cardiac Memory Induced by Ventricular Pacing. | Hypokalemia increases the vulnerability to ventricular fibrillation. We hypothesize that the apamin-sensitive small-conductance calcium-activated potassium current (IKAS) is activated during hypokalemia and that IKAS blockade is proarrhythmic.</AbstractText>Optical mapping was performed in 23 Langendorff-perfused rabbit ventricles with atrioventricular block and either right or left ventricular pacing during normokalemia or hypokalemia. Apamin prolonged the action potential duration (APD) measured to 80% repolarization (APD80) by 26 milliseconds (95% confidence interval [CI], 14-37) during normokalemia and by 54 milliseconds (95% CI, 40-68) during hypokalemia (P=0.01) at a 1000-millisecond pacing cycle length. In hypokalemic ventricles, apamin increased the maximal slope of APD restitution, the pacing cycle length threshold of APD alternans, the pacing cycle length for wave-break induction, and the area of spatially discordant APD alternans. Apamin significantly facilitated the induction of sustained ventricular fibrillation (from 3 of 9 hearts to 9 of 9 hearts; P=0.009). Short-term cardiac memory was assessed by the slope of APD80 versus activation time. The slope increased from 0.01 (95% CI, -0.09 to 0.12) at baseline to 0.34 (95% CI, 0.23-0.44) after apamin (P<0.001) during right ventricular pacing and from 0.07 (95% CI, -0.05 to 0.20) to 0.54 (95% CI, 0.06-1.03) after apamin infusion (P=0.045) during left ventricular pacing. Patch-clamp studies confirmed increased IKAS in isolated rabbit ventricular myocytes during hypokalemia (P=0.038).</AbstractText>Hypokalemia activates IKAS to shorten APD and maintain repolarization reserve at late activation sites during ventricular pacing. IKAS blockade prominently lengthens the APD at late activation sites and facilitates ventricular fibrillation induction.</AbstractText>© 2015 American Heart Association, Inc.</CopyrightInformation> |
10,333 | Apamin-Sensitive K+ Current Upregulation in Volume-Overload Heart Failure is Associated with the Decreased Interaction of CK2 with SK2. | Recent studies have shown that the sensitivity of apamin-sensitive K(+) current (I KAS, mediated by apamin-sensitive small conductance calcium-activated potassium channels subunits) to intracellular Ca(2+) is increased in heart failure (HF), leading to I KAS upregulation, action potential duration shortening, early after depolarization, and recurrent spontaneous ventricular fibrillation. We hypothesized that casein kinase 2 (CK2) interacted with small conductance calcium-activated potassium channels (SK) is decreased in HF, and protein phosphatase 2A (PP2A) is increased on the opposite, upregulating the sensitivity of I KAS to intracellular Ca(2+) in HF. Rat model of volume-overload HF was established by an abdominal arteriovenous fistula procedure. The expression of SK channels, PP2A and CK2 was detected by Western blot analysis. Interaction and colocalization of CK2 with SK channel were detected by co-immunoprecipitation analysis and double immunofluorescence staining. In HF rat left ventricle, SK3 was increased by 100 % (P < 0.05), and SK2 was not significantly changed. PP2A protein was increased by 94.7 % in HF rats (P < 0.05), whereas the level of CK2 was almost unchanged. We found that CK2 colocalized with SK2 and SK3 in rat left ventricle. With anti-CK2α antibody, SK2 and SK3 were immunoprecipitated, the level of precipitated SK2 decreased by half, whereas precipitated SK3 was almost unchanged. In conclusion, the increased expression of total PP2A and decreased interaction of CK2 with SK2 may underlie enhanced sensitivity of I KAS to intracellular Ca(2+) in volume-overload HF rat. |
10,334 | Meta-Analysis of the Relation of Ventricular Arrhythmias to All-Cause Mortality After Implantation of a Left Ventricular Assist Device. | Ventricular arrhythmias (VAs) are commonly reported after implantation of left ventricular assist devices (LVADs). Their relation to all-cause mortality and potential risk factors remains unclear. We conducted a meta-analysis of observational studies with the primary objective of evaluating the association of post-LVAD VAs with all-cause mortality at 60, 120, and 180 days. The secondary end point was the association of potential risk factors (cause of cardiomyopathy, indication for LVAD, and history of VA) with mortality in patients with post-LVAD VAs. We searched MEDLINE, Embase, and Cochrane Central from 2001 to 2015. Two reviewers independently searched, selected, and assessed quality of included studies with differences resolved by consensus. Data were collected and analyzed using random- and fixed-effect model, as appropriate, with inverse-variance weighting. Of 2,393 studies identified, 9 observational studies were eligible including 1,179 patients with a mean follow-up of 220 days. Post-LVAD VAs were associated with increased risk of all-cause mortality after adjusting for competing risk factors at 60 days (adjusted odds ratio [OR] 1.91, 95% confidence interval [CI] 1.18 to 3.11, p = 0.001), 120 days (adjusted OR 1.97, 95% CI 1.01 to 3.85, p = 0.05), and 180 days (adjusted OR 2.04, 95% CI 1.01 to 4.15, p = 0.05). Using meta-regression analysis, it was found that only history of VA was a risk factor for mortality after LVAD implantation. In conclusion, post-LVAD VA is associated with an increased risk of all-cause mortality with pre-LVAD VAs acting as a risk factor. This meta-analysis, despite being only hypothesis generating, sets the stage for prospective collection of VA information in a prospective device trial or in the Interagency Registry for Mechanically Assisted Circulatory Support. |
10,335 | The Wearable Cardioverter Defibrillator: an Early Single Centre Australian Experience. Some Pitfalls and Caveats for Use. | Wearable Cardioverter Defibrillators (WCD) have been effectively used for more than a decade in North America and Europe for prevention of sudden cardiac death (SCD) due to ventricular arrhythmias. This device has only recently been available in Australia.</AbstractText>At Westmead hospital, WCD has been used since 2013 as a bridging therapy to an implantable cardioverter defibrillator (ICD) for those at high risk, but are temporarily not suitable for an implantable device. Indications for use were explanted infected ICD, dilated cardiomyopathy, post partum cardiomyopathy, valvular heart disease and myocarditis. The default device settings were: ventricular tachycardia (VT) and ventricular fibrillation (VF) threshold of 150 bpm and 200 bpm respectively and response times were 60 secs for VT and 25 secs for VF.</AbstractText>WCD was used in eight patients. Duration of use ranged from five to 180 days with median of 77 days. Daily usage averaged 23.4±0.6hours. All except one were compliant with the device and none of our patients received shock or died during device usage. Four of the eight patients received ICD, two declined ICD, one was judged to no longer require ICD and one remains under assessment.</AbstractText>WCD is easy to use, well tolerated and is effective for SCD prevention in patients who are temporarily not suitable for ICD. However patients need to be actively followed-up to reduce the duration of WCD usage and thereby be cost effective.</AbstractText>Copyright © 2015. Published by Elsevier B.V.</CopyrightInformation> |
10,336 | Ventricular fibrillation development following atrial fibrillation after the ingestion of sildenaphil in a patient with Wolff-Parkinson-White syndrome. | Complications in the accessory pathway in Wolff-Parkinson-White (WPW) syndrome could cause different clinical conditions by inducing different arrhythmias. Atrial fibrillation (AF) is one of these arrhythmias and is important as it causes life-threatening arrhythmias. It is known that some drugs, underlying cardiac diseases, and the number of accessory pathways, cause a predisposition to this condition. In the current report, we presented a patient with WPW who was admitted to the emergency department with AF, wide QRS and a rapid ventricular response that progressed to ventricular fibrillation. |
10,337 | Assessing the atrial electromechanical coupling during atrial focal tachycardia, flutter, and fibrillation using electromechanical wave imaging in humans. | Minimally-invasive treatments of cardiac arrhythmias such as radio-frequency ablation are gradually gaining importance in clinical practice but still lack a noninvasive imaging modality which provides insight into the source or focus of an arrhythmia. Cardiac deformations imaged at high temporal and spatial resolution can be used to elucidate the electrical activation sequence in normal and paced human subjects non-invasively and could potentially aid to better plan and monitor ablation-based arrhythmia treatments. In this study, a novel ultrasound-based method is presented that can be used to quantitatively characterize focal and reentrant arrhythmias. Spatio-temporal maps of the full-view of the atrial and ventricular mechanics were obtained in a single heartbeat, revealing with otherwise unobtainable detail the electromechanical patterns of atrial flutter, fibrillation, and tachycardia in humans. During focal arrhythmias such as premature ventricular complex and focal atrial tachycardia, the previously developed electromechanical wave imaging methodology is hereby shown capable of identifying the location of the focal zone and the subsequent propagation of cardiac activation. During reentrant arrhythmias such as atrial flutter and fibrillation, Fourier analysis of the strains revealed highly correlated mechanical and electrical cycle lengths and propagation patterns. High frame rate ultrasound imaging of the heart can be used non-invasively and in real time, to characterize the lesser-known mechanical aspects of atrial and ventricular arrhythmias, also potentially assisting treatment planning for intraoperative and longitudinal monitoring of arrhythmias. |
10,338 | Irrigated Needle Ablation Creates Larger and More Transmural Ventricular Lesions Compared With Standard Unipolar Ablation in an Ovine Model. | Ventricular tachycardia recurrence can occur after ventricular tachycardia ablation because of incomplete and nontransmural ventricular lesion formation. We sought to compare the lesions made by a novel irrigated needle catheter to conventional radiofrequency lesions.</AbstractText>Thirteen female sheep (4.6±0.7 years, 54±8 kg) were studied. In 7 sheep, 60-s radiofrequency applications were performed using an irrigated needle catheter. In 6 sheep, conventional lesions were made using a 4-mm irrigated catheter. 1.5T in vivo and high-density magnetic resonance imaging (9.4T) were performed on explanted hearts from animals receiving needle radiofrequency. Conventional lesion volume was calculated as (1/6)×π×(A×B(2)+C×D(2)/2). Needle lesion volume was measured as Σ(π×r(2))/2 with a slice thickness of 1 mm. The dimensions of all lesions were also measured on gross pathology. Additional histological analysis of the needle lesions was performed. One hundred twenty endocardial left ventricular ablation lesions (conventional, n=60; needle, n=60) were created. At necropsy, more lesions were found using needle versus conventional radiofrequency (90% versus 75%; P<0.05). Comparing needle versus conventional radiofrequency: lesion volume was larger (1030±362 versus 488±384 mm(3); P<0.001), lesion depth was increased (9.9±2.7 versus 5±2.4 mm; P<0.001), and more transmural lesions were created (62.5% versus 17%; P<0.01). Pericardial contrast injection was observed in 4 apical attempts using needle radiofrequency, however, with no adverse effects. Steam pops occurred in 3 attempts using conventional radiofrequency.</AbstractText>Irrigated needle ablation is associated with more frequent, larger, deeper, and more often transmural lesions compared with conventional irrigated ablation. This technology might be of value to treat intramural or epicardial ventricular tachycardia substrates resistant to conventional ablation.</AbstractText>© 2015 American Heart Association, Inc.</CopyrightInformation> |
10,339 | Influence of acute glycaemic level on measures of myocardial infarction in non-diabetic pigs. | Patients with diabetes are at increased risk of experiencing myocardial infarction. The influence of the prevailing plasma glucose level on infarction and mortality after acute ischaemia is however unknown. The aim was to study the effect of the acute plasma glucose level on the myocardial infarction size in a closed-chest pig model.</AbstractText>38 non-diabetic pigs were randomised to hypoglycaemic (1.8-2.2 mmol/l; n = 15), normoglycaemic (5-7 mmol/l; n = 12) or hyperglycaemic glucose clamping (22-23 mmol/l; n = 11). After 30 min within glucose target myocardial infarction was induced for 30 min followed by reperfusion for 120 min. Hereafter the heart was double-stained to delineate infarction from viable tissue within the area at risk.</AbstractText>Mean infarction size was 201 ± 35 mm(2) (mean ± SEM) in the hypoglycaemic group, 154 ± 40 mm(2) in the normoglycaemic group and 134 ± 40 mm(2) in the hyperglycaemic group, with no differences in infarction size, infarct/area at risk ratio or troponin T levels between the groups. There was no difference in incidence of ventricular fibrillation or mortality between the groups.</AbstractText>No statistically significant associations were observed between the acute glycaemic level and measures of myocardial infarction, rates of ventricular fibrillation and subsequent premature death in the setting of acute ischaemia and reperfusion.</AbstractText> |
10,340 | [The left ventricular assistance device was used for anomalous origin of the left coronary artery from the pulmonary artery in perioperative period]. | To review the experience of left ventricular assistance device (LVAD) using for anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) in perioperative period.</AbstractText>There were 29 patients with ALCAPA underwent surgical repair from May 2006 to May 2013. The mean age was 6.5 months (ranging from 3.3 to 12.1 months). The mean weight was 6.2 kg (ranging from 4.1 to 9.5 kg). Diagnosis was established by echocardiography in all patients. There were clinical symptomatic of the severe heart dysfunction and ejection fraction were 23% to 45%. Mitral insufficiency was moderate to severe in 8 patients and less than moderate in others. Surgical methods included the intrapulmonary tunnel (Takeuchi procedure) of 4 cases, direct reimplantation of the left coronary artery onto the aorta of 6 cases and reimplantation by pericardiac patch enlarge of 19 cases. Valvuloplasty were performed in 5 patients with mitral severe insufficiency. Twenty-two patients were treated only by medicine therapy. LVAD was used in 7 patients: there were 3 patients with low blood pressure at the end of surgical repair and 4 patients with low cardio output within 24 hours postoperatively.</AbstractText>Postoperatively, transesophageal echocardiography demonstrated that blood flow of the left coronary artery is fluently but left ventricular is also largement. The hemodynamic of 18 patients was stable in medicine group but 3 patients were sudden died of low cardiao output and ventricular fibrillation respectively. One patient was died of diffuse intravascular coagulation at the time of 72 hours after operation. The hemodynamic was stable in 6 patients in LVAD group and the devices after using time from 72 to 108 hours was taken down except one patient died of multi-organ dysfunction. The hospital mortality was 5/29 (17.2%). Nineteen survival (19/24) was followed up of 3.5 years (ranging from 1 to 7 years). Reoperations was performed for one patient with the supravalvar pulmonary stenosis due to the Takeuchi procedure 4 years postoperatively. Echocardiographic demonstrated that the blood flow of the left coronary artery are fluently. Mitral insufficiency was moderate in 2 cases, mild to moderate in 9 cases and mild in 8 cases. The ejection fraction value were 43% to 55% and apparent arrhythmia didn't occur.</AbstractText>Although late results are satisfactory and left ventricular function always recovery, early mortality is higher even though the protective methods are carried out during the whole cardiopulmonary bypass procedure. In order to decrease the early mortality, heart function evaluation and LVAD should be used as an effective cardiac support technique to prevent heart failure in time.</AbstractText> |
10,341 | Electrochemotherapy of colorectal liver metastases--an observational study of its effects on the electrocardiogram. | Electrochemotherapy (ECT) is a combined treatment in which high voltage electroporation (EP) pulses are used to facilitate the uptake of a chemotherapeutic drug into tumor cells, thus increasing antitumor effectiveness of the drug. The effect of ECT of deep-seated tumors located close to the heart on functioning of the heart has not been previously investigated. In this study, we investigate the effects of intra-abdominal ECT of colorectal liver metastases on functioning of the heart during the early post-operative care period.</AbstractText>For ECT high voltage EP pulses with amplitudes of up to 3000 V and 30 A were delivered in synchronization with electrical activity of the heart. Holter electrocardiographic (ECG) signals were obtained from 10 patients with colorectal liver metastases treated with ECT. ECG was recorded during the periods of 24 hours before and after the surgical procedure involving ECT. Four-hour long night-time ECG segments from both periods exhibiting the highest level of signal stationarity were analyzed and compared. Changes in several ECG and heart rate variability (HRV) parameters were evaluated.</AbstractText>No major heart rhythm changes (i.e., induction of extrasystoles, ventricular tachycardia or fibrillation) or pathological morphological changes (i.e., ST segment changes) indicating myocardial ischemia were found. However, we found several minor statistically significant but clinically irrelevant changes in HRV parameters after ECT procedures: a decrease in median values of the mean NN interval, a decrease in the low-frequency and in the normalized low-frequency component, and an increase in the normalized high-frequency component.</AbstractText>Only minor effects of intra-abdominal ECT treatment on functioning of the heart were found. They were expressed as statistically significant but clinically irrelevant changes in heart rate and long-term HRV parameters and were as such not life-threatening to the patients. The nature of these changes is such that they can be attributed to the known effects of the drugs given to the patients in the post-operative care. Further investigation is still warranted to unambiguously resolve whether ECT with high voltage EP pulses applied in immediate vicinity of the heart is responsible for the observed effects.</AbstractText> |
10,342 | Management of Brugada Syndrome: Thirty-Three-Year Experience Using Electrophysiologically Guided Therapy With Class 1A Antiarrhythmic Drugs. | Information on long-term clinical outcome of patients with Brugada syndrome treated with electrophysiologically guided class 1A antiarrhythmic drugs (AAD) is limited.</AbstractText>An aggressive protocol of programmed ventricular stimulation was performed in 96 patients with Brugada syndrome (88% males; mean age, 39.8±15.9 years). Ten patients were cardiac arrest survivors, 27 had presented with syncope, and 59 were asymptomatic. Ventricular fibrillation was induced in 66 patients, including 100%, 74%, and 61% of patients with cardiac arrest, syncope, and no symptoms, respectively. All but 6 of the 66 patients with inducible ventricular fibrillation underwent electrophysiological testing on quinidine (n=54), disopyramide (n=2), or both (n=4). Fifty-four (90%) patients were electrophysiological responders to >1 AAD with similar efficacy rates (≈90%) in all patients groups. Patients with no inducible ventricular fibrillation at baseline were left on no therapy. After a mean follow-up of 113.3±71.5 months, 92 patients were alive, whereas 4 died from noncardiac causes. No arrhythmic event occurred during class 1A AAD therapy in any of electrophysiological drug responders and in patients with no baseline inducible ventricular fibrillation. Arrhythmic events occurred in only 2 cardiac arrest survivors treated with implantable cardioverter-defibrillator alone but did not recur on quinidine. All cases of recurrent syncope (n=12) were attributed to a vasovagal (n=10) or nonarrhythmic mechanism (n=2). Class 1A AAD therapy resulted in 38% incidence of side effects that resolved after drug discontinuation.</AbstractText>Our data suggest that electrophysiologically guided class 1A AAD treatment has a place in our therapeutic armamentarium for all types of patients with Brugada syndrome.</AbstractText>© 2015 American Heart Association, Inc.</CopyrightInformation> |
10,343 | Atrial SERCA2a Overexpression Has No Affect on Cardiac Alternans but Promotes Arrhythmogenic SR Ca2+ Triggers. | Atrial fibrillation (AF) is the most common arrhythmia in humans, yet; treatment has remained sub-optimal due to poor understanding of the underlying mechanisms. Cardiac alternans precede AF episodes, suggesting an important arrhythmia substrate. Recently, we demonstrated ventricular SERCA2a overexpression suppresses cardiac alternans and arrhythmias. Therefore, we hypothesized that atrial SERCA2a overexpression will decrease cardiac alternans and arrhythmias.</AbstractText>Adult rat isolated atrial myocytes where divided into three treatment groups 1) Control, 2) SERCA2a overexpression (Ad.SERCA2a) and 3) SERCA2a inhibition (Thapsigargin, 1μm). Intracellular Ca2+ was measured using Indo-1AM and Ca2+ alternans (Ca-ALT) was induced with a standard ramp pacing protocol.</AbstractText>As predicted, SR Ca2+ reuptake was enhanced with SERCA2a overexpression (p< 0.05) and reduced with SERCA2a inhibition (p<0.05). Surprisingly, there was no difference in susceptibility to Ca-ALT with either SERCA2a overexpression or inhibition when compared to controls (p = 0.73). In contrast, SERCA2a overexpression resulted in increased premature SR Ca2+ (SCR) release compared to control myocytes (28% and 0%, p < 0.05) and concomitant increase in SR Ca2+ load (p<0.05). Based on these observations we tested in-vivo atrial arrhythmia inducibility in control and Ad.SERCA2a animals using an esophageal atrial burst pacing protocol. There were no inducible atrial arrhythmias in Ad.GFP (n = 4) animals though 20% of Ad.SERCA2a (n = 5) animals had inducible atrial arrhythmias (p = 0.20).</AbstractText>Our findings suggest that unlike the ventricle, SERCA2a is not a key regulator of cardiac alternans in the atrium. Importantly, SERCA2a overexpression in atrial myocytes can increase SCR, which may be arrhythmogenic.</AbstractText> |
10,344 | Predictors of Arrhythmic Events Detected by Implantable Loop Recorders in Renal Transplant Candidates. | The recording of arrhythmic events (AE) in renal transplant candidates (RTCs) undergoing dialysis is limited by conventional electrocardiography. However, continuous cardiac rhythm monitoring seems to be more appropriate due to automatic detection of arrhythmia, but this method has not been used.</AbstractText>We aimed to investigate the incidence and predictors of AE in RTCs using an implantable loop recorder (ILR).</AbstractText>A prospective observational study conducted from June 2009 to January 2011 included 100 consecutive ambulatory RTCs who underwent ILR and were followed-up for at least 1 year. Multivariate logistic regression was applied to define predictors of AE.</AbstractText>During a mean follow-up of 424 ± 127 days, AE could be detected in 98% of patients, and 92% had more than one type of arrhythmia, with most considered potentially not serious. Sustained atrial tachycardia and atrial fibrillation occurred in 7% and 13% of patients, respectively, and bradyarrhythmia and non-sustained or sustained ventricular tachycardia (VT) occurred in 25% and 57%, respectively. There were 18 deaths, of which 7 were sudden cardiac events: 3 bradyarrhythmias, 1 ventricular fibrillation, 1 myocardial infarction, and 2 undetermined. The presence of a long QTc (odds ratio [OR] = 7.28; 95% confidence interval [CI], 2.01-26.35; p = 0.002), and the duration of the PR interval (OR = 1.05; 95% CI, 1.02-1.08; p < 0.001) were independently associated with bradyarrhythmias. Left ventricular dilatation (LVD) was independently associated with non-sustained VT (OR = 2.83; 95% CI, 1.01-7.96; p = 0.041).</AbstractText>In medium-term follow-up of RTCs, ILR helped detect a high incidence of AE, most of which did not have clinical relevance. The PR interval and presence of long QTc were predictive of bradyarrhythmias, whereas LVD was predictive of non-sustained VT.</AbstractText> |
10,345 | Pheochromocytoma Presenting as Partial HELLP Syndrome. | Diagnosis of pheochromocytoma in partial HELLP syndrome is extremely rare. We report a case of a 25-year-old multigravida woman at 30 weeks of gestation who presented with clinical features consistent with partial HELLP syndrome. Her symptoms were not controlled by pharmacologic therapy, and the patient underwent urgent cesarean section. The patient gave birth to a viable baby, but she sustained an episode of ventricular fibrillation intraoperatively that did not result in any long-term sequelae. The patient's symptoms persisted postoperatively and work-up for secondary etiologies of hypertension demonstrated a right adrenal pheochromocytoma. Following resection, the patient's signs and symptoms resolved, and her lab tests normalized. |
10,346 | Novel Therapies for Myocardial Irritability following Extreme Hydroxychloroquine Toxicity. | Introduction. Hydroxychloroquine (HCQ) overdose is rare and potentially deadly when consumed in large doses. Management of severe HCQ toxicity is limited and infrequently reported. This report presents the case of a massive ingestion of HCQ. Case Report. A 23-year-old female presents following an intentional ingestion of approximately 40 g of HCQ. Within six hours after ingestion, she developed severe hemodynamic instability resulting from myocardial irritability with frequent ventricular ectopic activity leading to runs of polymorphic ventricular tachycardia (PMVT) and ventricular fibrillation (VF) requiring multiple defibrillations. Additional treatments included intravenous diazepam, epinephrine, norepinephrine, sodium bicarbonate, and magnesium sulfate. Despite the ongoing hemodynamic instability, the patient was also treated with Intralipid (ILE) and received hemodialysis. Improvements in her hemodynamics were observed after 18 hours. She survived her massive overdose of HCQ. Conclusion. HCQ poisoning is rare but serious because of its rapid progression to life-threatening symptoms. Hemodynamic support, gastric decontamination, electrolyte monitoring and replacement, and management of arrhythmias are the mainstays of treatment. The combined role of dialysis and ILE in the setting of massive HCQ overdose may improve outcomes. |
10,347 | Suicidal Zinc Phosphide Poisoning Unmasking Brugada Syndrome and Triggering Near Fatal Ventricular Arrhythmia. | Brugada syndrome (BrS) is an inherited channelopathy associated with increased incidence of ventricular arrhythmias and has many acquired triggers. Zinc phosphide (ZnP) is a rodenticide and is commonly implicated in suicidal poison ingestion. ZnP poisoning can cause myocardial toxicity and death. We report a case of ZnP poisoning that triggered a type I Brugada pattern and ventricular fibrillation in a 67-year-old male. He had no other features of toxicity and recovered later. As metal phosphide is the commonest toxin involved in suicidal poisoning in India and BrS being endemic here, this case highlights an important clinical problem. |
10,348 | Advisory External Defibrillator Availability in General Practice. | This study aimed to describe the availability of advisory external defibrillators (AEDs) in Irish General Practice. The study utilised a computer generated random sample of Irish general practitioners and involved a postal questionnaire, with telephone follow up of non-responders. The cohort of GPs already known to possess an AED (via participation in the Merit Project) was excluded. 115 valid paper survey responses were received representing a response rate of 59%. 5 of the responding GPs identified themselves as Merit project participants and were excluded from data analysis. 74/110 GPs (67%) reported having one or more AED(s) available for use at their practice. 41/77 GPs (53%) who had not responded to the paper survey but were contactable by telephone had an AED available. When AED availability was examined by practice setting a higher proportion of rural and mixed settings had AEDs available than in urban and city areas. Cost was reported as the most common reason for not having an AED. |
10,349 | Digoxin Is Associated With Increased All-cause Mortality in Patients With Atrial Fibrillation Regardless of Concomitant Heart Failure: A Meta-analysis. | For decades, digoxin has been widely used to control ventricular rate in atrial fibrillation (AF). However, it remains controversial as to whether digoxin is associated with increased mortality in AF. In this study, we searched relevant studies that were published before December 1, 2014, in PubMed, EMBASE, and the Cochrane central databases. We systematically reviewed the references and performed a meta-analysis of 8 carefully selected studies with 302,738 patients who were included for the final analysis. It was shown that digoxin use was associated with increased risk of all-cause mortality in AF overall [hazard ratio (HR) = 1.375, 95% confidence intervals (CI), 1.201-1.574, P = 0.0001]. Subgroup analysis further revealed that digoxin was associated with increased all-cause mortality in patients with AF, which was complicated by heart failure (HF) (HR = 1.201, CI, 1.074- 1.344, P = 0.001), and in those subjects without HF (HR = 1.172, CI, 1.148-1.198, P = 0.0001). Sensitivity analyses found results to be robust. Our findings indicated that digoxin use was associated with significantly increased all-cause mortality in patients with AF regardless of concomitant HF. We suggest that digoxin should not be preferentially used over other rate control medications in AF. |
10,350 | Acute effects of intravenous dronedarone on electrocardiograms, hemodynamics and cardiac functions in anesthetized dogs. | Dronedarone is a class III antiarrhythmic that has been used for management of atrial fibrillation in humans, but limited information was found in dogs. The objective of this study was to determine the acute effects of escalating concentrations of dronedarone on electrocardiograms (ECG), hemodynamics and cardiac mechanics in healthy dogs. A total of 7 beagle dogs were anesthetized with isoflurane and instrumented to obtain lead II ECG, pressures at ascending aorta, right atrium, pulmonary artery and left ventricle, and left ventricular pressure-volume relationship. Five dogs were given vehicle and followed by escalating doses of dronedarone (0.5, 1.0 and 2.5 mg/kg, 15 min for each dose), and two dogs were used as a vehicle-treated control. All parameters were measured at 15 min after the end of each dose. The results showed that all parameters in vehicle-treated dogs were unaltered. Dronedarone at 2.5 mg/kg significantly lengthened PQ interval (P<0.01), reduced cardiac output (P<0.01) and increased systemic vascular resistance (P<0.01). Dronedarone produced negative inotropy assessed by significantly lowered end-systolic pressure-volume relationship, preload recruitable stroke work, contractility index and dP/dtmax. It also impaired diastolic function by significantly increased end-diastolic pressure-volume relationship, tau and dP/dtmin. These results suggested that acute effects of dronedarone produced negative dromotropy, inotropy and lusitropy in anesthetized dogs. Care should be taken when given dronedarone to dogs, especially when the patients have impaired cardiac function. |
10,351 | Feeding the fibrillating heart: Dichloroacetate improves cardiac contractile dysfunction following VF. | Ventricular fibrillation (VF) is an important cause of sudden cardiac arrest following myocardial infarction. Following resuscitation from VF, decreased cardiac contractile function is a common problem. During and following myocardial ischemia, decreased glucose oxidation, increased anaerobic glycolysis for cardiac energy production are harmful and energetically expensive. The objective of the present study is to determine the effects of dichloroacetate (DCA), a glucose oxidation stimulator, on cardiac contractile dysfunction following ischemia-induced VF. Male Sprague-Dawley rat hearts were Langendorff perfused in Tyrode's buffer. Once stabilized, hearts were subjected to 15 min of global ischemia and 5 min of aerobic reperfusion in the presence or absence of DCA. At the 6th min of reperfusion, VF was induced electrically, and terminated. Left ventricular (LV) pressure was measured using a balloon. Pretreatment with DCA significantly improved post-VF left ventricular developed pressure (LVDP) and dp/dtmax. In DCA-pretreated hearts, post-VF lactate production and pyruvate dehydrogenase (PDH) phosphorylation were significantly reduced, indicative of stimulated glucose oxidation, and inhibited anaerobic glycolysis by activation of PDH. Epicardial NADH fluorescence was increased during global ischemia above preischemic levels, but decreased below preischemia levels following VF, with no differences between nontreated controls and DCA-pretreated hearts, whereas DCA pretreatment increased NADH production in nonischemic hearts. With exogenous fatty acids (FA) added to the perfusion solution, DCA pretreatment also resulted in improvements in post-VF LVDP and dp/dtmax, indicating that the presence of exogenous FA did not affect the beneficial actions of DCA. In conclusion, enhancement of PDH activation by DCA mitigates cardiac contractile dysfunction following ischemia-induced VF. |
10,352 | Quality of life after videoscopic left cardiac sympathetic denervation in patients with potentially life-threatening cardiac channelopathies/cardiomyopathies. | Left cardiac sympathetic denervation (LCSD) provides an additive or potentially alternative treatment option for patients with life-threatening cardiac channelopathies/cardiomyopathies.</AbstractText>We sought to examine the effects of LCSD on quality of life (QOL).</AbstractText>From November 2005 to May 2013, 109 patients who underwent LCSD were subsequently sent postoperative QOL surveys.</AbstractText>Of 109 patients, 8 (7%) could not be contacted. Of the remaining 101 patients, 62 returned surveys (response rate 61%). There were an average of 4.1 ± 1.8 self-reported side effects immediately after LCSD. The most common anticipated side effects included unilateral hand dryness, color or temperature variance between sides of the face, and abnormal sweating. Although parent-reported pediatric physical QOL scores were lower than national norms, there were no differences in psychosocial QOL or disability scores (P = .09 and .33, respectively). QOL scores for adult patients were not significantly different from a US normative sample. Adult LCSD patients reported less disability than a US normative sample (P < .01). There was no correlation between QOL scores and the presence of anticipated side effects. However, among the subset of pediatric patients who continued to receive ventricular fibrillation-terminating implantable cardioverter-defibrillator shocks after LCSD, there was a correlation between their disability scores and the number of reported shocks (Spearman correlation = 0.56). The majority of patients/parents reported that they were very or somewhat satisfied with their surgery (or their child's surgery) and would definitely or probably recommend LCSD to another patient.</AbstractText>Despite the anticipated side effects associated with LCSD, patients are satisfied with their surgery and indicate that they would recommend the surgery to another patient.</AbstractText>Copyright © 2016 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
10,353 | Infection and mortality after implantation of a subcutaneous ICD after transvenous ICD extraction. | The subcutaneous implantable cardioverter-defibrillator (S-ICD) provides an alternative to the transvenous implantable cardioverter-defibrillator (TV-ICD). Patients undergoing TV-ICD explantation may be eligible for reimplantation with an S-ICD; however, information on safety outcomes in this complex population is limited.</AbstractText>This analysis was designed to provide outcome and safety data from S-ICD patients who received their device after TV-ICD explantation.</AbstractText>Patients in the S-ICD IDE Study and EFFORTLESS Registry with a prior TV-ICD explantation, as well as those with no prior implantable cardioverter-defibrillator (ICD), were included. Patients were divided into 3 groups: those implanted with the S-ICD after TV-ICD extraction for system-related infection (n = 75); those implanted after TV-ICD extraction for reasons other than system-related infection (n = 44); and patients with no prior ICD (de novo implantations, n = 747).</AbstractText>Mean follow-up duration was 651 days, and all-cause mortality was low (3.2%). Patients previously explanted for TV-ICD infection were older (55.5 ± 14.6, 47.8 ± 14.3 and 49.9 ± 17.3 years in the infection, noninfection, and de novo cohorts, respectively; P = .01), were more likely to have received the ICD for secondary prevention (42.7%, 37.2% and 25.6%; P < 0.0001) and had higher percentages of comorbidities, including atrial fibrillation, congestive heart failure, diabetes mellitus, and hypertension, in line with the highest mortality rate (6.7%). Major infection after S-ICD implantation was low in all groups, with no evidence that patients implanted with the S-ICD after TV-ICD explantation for infection were more likely to experience a subsequent reinfection.</AbstractText>The S-ICD is a suitable alternative for TV-ICD patients whose devices are explanted for any reason. Postimplantation risk of infection remains low even in patients whose devices were explanted for prior TV-ICD infection.</AbstractText>Copyright © 2016 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
10,354 | Risk stratification in Brugada syndrome: Clinical characteristics, electrocardiographic parameters, and auxiliary testing. | Risk stratification in Brugada syndrome remains a clinical challenge because the event rate is low but the presenting symptom is often cardiac arrest (CA). We review the data on risk stratification. A history of CA or malignant syncope is a strong predictor of spontaneous ventricular fibrillation (VF), whereas the prognostic value of a history of familial sudden death and the presence of a SCN5A mutation are less well defined. On the electrocardiogram, the presence of spontaneous type I electrocardiogram increases the risk for VF in all studies, whereas the presence of fragmented QRS complexes and early repolarization correlates with increased risk in several studies. Signal-averaged techniques using late potentials and microscopic T-wave alternans show some promising results in small studies that need to be confirmed. The value of electrophysiologic studies for predicting spontaneous VF remains controversial, and this includes programmed stimulation protocols that avoid a third extrastimuli or stimulation from the right ventricular outflow. Risk prediction is particularly challenging in children and women. |
10,355 | Detection and evaluation of renal biomarkers in a swine model of acute myocardial infarction and reperfusion. | The prevalence of type 1 cardiorenal syndrome (CRS) is increasing and strongly associated with long-term mortality. However, lack of reliable animal models and well-defined measures of renoprotection, made early diagnosis and therapy difficult. We previously successfully established the swine acute myocardial infarction (AMI) model of ischemia-reperfusion by blocking left anterior descending branch (LAD). Reperfusion was performed after 90-minute occlusion of the LAD. AMI was confirmed by ECG and left ventricular angiography (LVG). Then those 52 survived AMI reperfusion swine, including ventricular fibrillation-cardiac arrest after restoration of blood flow, were randomly divided into four groups (four/group) according to different interventions: resuscitation in room temperature, resuscitation with 500 ml saline in room temperature, resuscitation with 4°C 500 ml saline and normal control (with no intervention of resuscitation). Each group was further observed in four groups according to different time of resuscitation after ventricular arrhythmias: 1, 3, 5, 10-minute reperfusion after ventricular arrhythmias. Plasma and random urine were collected to evaluate renal function and test renal biomarkers of acute kidney injury (AKI). Our swine AMI model of ischemia-reperfusion provoked subclinical AKI with the elevation of the tubular damage biomarker, NGAL, IL-18 and L-FABP. Renal damage rapidly observed after hemodynamic instability, rather than observation after several hours as previously reported. The increasing rate of biological markers declined after interventions, however, its impact on the long-term prognosis remains to be further studied. These data show that elevation of tubular damage biomarkers without glomerular function loss may indicate appropriate timing for effective renoprotections like hypothermia resuscitation in type 1 CRS. |
10,356 | Epidemiology of Right Ventricular Dysfunction in Heart Failure with Preserved Ejection Fraction. | Despite increasing recognition of the importance of right ventricular (RV) dysfunction (RVD) in the pathophysiology of left heart disease, our understanding of its epidemiology in heart failure (HF) with preserved ejection fraction (HFpEF) remains incomplete. In part, this is due to complex RV geometry and challenging and inconsistent assessment of RV function . Consequently, the prevalence of RVD in HFpEF varies widely depending on study design and population characteristics; however, on average is observed in one third of HFpEF subjects. In these patients, RVD is most commonly associated with an advanced HF state, pulmonary hypertension, atrial fibrillation, right ventricular pacing, and tricuspid valve regurgitation. Whether these associations are causal remains uncertain.Right ventricular dysfunction is recognized to confer poor outcomes in patients with HFpEF, including increased HF hospitalization and higher overall and cardiovascular mortality. Moreover, the prognostic significance of RVD in HFpEF is independent of, and additive to, the severity of pulmonary hypertension. As greater emphasis is placed on phenotyping subgroups of patients with HFpEF in order to tailor therapeutic strategies, improved characterization of the large subset of HFpEF patients with RVD, with and without antecedent pulmonary hypertension may yield critical insights, which inform novel therapeutic interventions. |
10,357 | [A 65-year-old man with wearable cardioverter/defibrillator early after acute myocardial infarction]. | A 65-year-old man with severe coronary artery disease and coronary artery bypass graft presented with an acute posterior ST-elevation myocardial infarction. Immediate percutaneous coronary intervention resulted in successful revascularisation of the culprit lesion (RCx) with several remaining coronary stenoses. Despite the reduced left ventricular ejection fraction, no primary prevention indication for an implantable cardioverter/defibrillator early after myocardial infarction existed. Due to the complex coronary anatomy with several remaining stenotic vessels we regarded the patient to be at a particularly high risk for lethal ventricular arrhythmias and provided him with a wearable cardioverter defibrillator (WCD). Twenty-six days later, he experienced spontaneous ventricular tachycardia and fibrillation which was successfully treated with high voltage therapy by the WCD. Subsequently, we decided to implant him an ICD following secondary prevention indication. Besides established indications for primary prevention ICD therapy, some patients early after myocardial infarction may be at a particularly high risk for sudden cardiac death. Temporary protection with a WCD in carefully selected patients can offer a safe opportunity for later reevaluation of permanent ICD implantation depending on the course of left ventricular ejection fraction and the occurrence of arrhythmia. |
10,358 | Impact of Remote Monitoring on Clinical Outcomes. | Follow-up of patients with cardiac implantable electronic devices is challenging due to both their increasing volume and technical complexity coupled to increasing clinical complexity of recipient patients. Remote monitoring (RM) offers an opportunity to resolve some of these difficulties by improving clinic efficiencies and providing a mechanism for device monitoring and patient management. Several recent randomized clinical trials and registries have demonstrated that RM may reduce in-hospital visit numbers, time required for patient follow-up, physician and nurse time, and hospital and social costs. Furthermore, patient retention and adherence to follow-up schedule are significantly improved by RM. Continuous wireless monitoring of data stored in the device memory with automatic alerts allows early detection of device malfunctions and of events, such as atrial fibrillation, ventricular arrhythmias, and heart failure suitable for clinical intervention. Early reaction may improve patient outcome. RM is easy to use and patients showed a high level of acceptance and satisfaction. Implementing RM in daily practice may require changes in clinic workflow. New organizational models promote significant efficiencies regarding physician and nursing time. Data management techniques are under development. Despite these demonstrable advantages of RM, adoption still remains modest, even in health care systems incentivized to use this follow-up method. |
10,359 | High atrioventricular phase index on near-field intracardiac electrogram is associated with risk of ventricular arrhythmia. | The purposes of this study were to characterize and quantify concordance between consecutive atrial and ventricular activation time points through analysis of phases and to explore its association with outcomes in patients with implantable cardioverter-defibrillator (ICD). Patients with structural heart disease and dual-chamber ICDs underwent 5min baseline right ventricular (V) near-field and atrial (A) electrogram (EGM) recording. The cross-dependencies of phase dynamics of the changes in consecutive A (AA') and V (VV') were quantified and the AV phase dependency index was determined. In Cox regression analysis, a high AV phase index (in the highest quartile, >0.259) was significantly associated with higher risk of ventricular tachyarrhythmias (HR 2.84; 95% CI 1.05-7.67; P=0.04). In conclusion, in ICD patients with structural heart disease, high sinus AV phase dependency index on EGM is associated with the risk of ventricular arrhythmia. |
10,360 | The atherosclerosis of the sinus node artery is associated with an increased history of supra-ventricular arrhythmias: a retrospective study on 541 standard coronary angiograms. | Background. The ischemic damage of the sinus node (SN) is a well known cause of cardiac arrhythmias and can be a consequence of any flow abnormality in the sinus node artery (SNA). Accordingly we aimed this retrospective study to: (1) evaluate the suitability of the standard coronary angiography to study the SNA and (2) determine if the percentage of subjects with a positive retrospective history of supra-ventricular arrhythmias (SVA) differs in patients with normal and diseased SNA ascertained at the time of coronary angiography. Methods and Results. Out of the 541 coronary angiograms reviewed the SNA was visible for its entire course in 486 cases (89.8%). It was found to arise from the right side of the coronary circulation in 266 cases (54.7%) slightly more often than from the left, 219 cases (45.1%). One patient had 2 distinct SNA arising from either side of the coronary circulation. For the second objective, we studied the 333 patients with: (a) coronary artery disease (CAD), (b) properly evaluable SNA and (c) complete clinical history available. In 51 (15.3%) a SNA disease was found, 41.2% of them had a positive SVA history, mainly atrial fibrillation (AF), whereas only 7.4% of patients with a positive history of SVA could be found in the non-SNA diseased. This difference was statistically significant (P < 0.001). Conclusions. (1) The evaluation of the SNA is feasible in clinical practice during a standard coronary angiography; (2) this may be relevant since angiographically detectable SNA disease was significantly associated with a positive history of SVA. |
10,361 | Inappropriate mode switching clarified by using a chest radiograph. | An 80-year-old woman with a history of paroxysmal atrial fibrillation and atrioventricular node disease status post-dual chamber pacemaker placement was noted to have abnormal pacing episodes during a percutaneous coronary intervention. Pacemaker interrogation revealed a high number of short duration mode switching episodes. Representative electrograms demonstrated high frequency nonphysiologic recordings predominantly in the atrial lead. Intrinsic pacemaker malfunction was excluded. A chest radiograph showed excess atrial and ventricular lead slack in the right ventricular inflow. It was suspected that lead-lead interaction resulted in artifacts and oversensing, causing frequent short episodes of inappropriate mode switching. |
10,362 | Feasibility and accuracy of a new mobile electrocardiography device, ER-2000(®), in the diagnosis of arrhythmia. | We performed this study to evaluate the feasibility and accuracy of a new mobile electrocardiography (ECG) device, ER-2000(®), in detecting cardiac arrhythmia, by comparing it to a 12-lead ECG used as the gold standard.</AbstractText>Mode 1 of ER-2000(®) was recorded using three electrodes with cables attached to the anterior chest wall, and mode 2 was recorded using the side chest channel and finger channel. Standard 12-lead ECG was used to record with a speed of 25 mm/s, simultaneously.</AbstractText>Seventeen patients with complaints of palpitation were enrolled. Twelve-lead ECG revealed normal sinus rhythm in three patients, sinus tachycardia in one, atrial fibrillation (AF) in two, atrial tachycardia (AT) in one, first degree atrioventricular block in one, pacing rhythm in two patients who underwent permanent pacemaker implantation, AF with intermittent ventricular pacing in one, complete right bundle branch block in one, J-wave elevation in one, narrow QRS tachycardia in one, atrial premature beat (APB) in one, ventricular premature beat (VPB) in one, and narrow QRS tachycardia with intermittent aberrant conduction in one. Rhythm diagnosis obtained by the two different modes of ER-2000(®) was correlated with that obtained by the 12-lead ECG in all patients except in one in whom ER-2000(®) showed one APB while 12-lead ECG showed sinus rhythm. R-R interval was accurately recorded despite the detailed morphology of QRS, and T-wave was somewhat modified with the use of ER-2000(®). A pacing blip detected by 12-lead ECG was not detected by ER-2000(®) despite a similar wide QRS duration in the paced QRS.</AbstractText>A rhythm strip obtained using ER-2000(®) is accurate in diagnosing arrhythmia, despite some differences in the detailed morphology of the QRS and T-wave, and the pacing spike compared to those obtained by the 12-lead ECG.</AbstractText> |
10,363 | Immediate electrical storm of Torsades de Pointes after CRT-D implantation in an ischemic cardiomyopathy patient. | Cardiac resynchronization therapy with an implantable cardioverter-defibrillator (CRT-D) is the preferred treatment for patients with severe heart failure, dyssynchrony, and an increased risk of sudden cardiac death or for primary ventricular arrhythmia survivors. Rarely, left ventricular epicardial pacing can induce ventricular tachyarrhythmia rather than a beneficial effect. We describe an ischemic cardiomyopathy patient who underwent CRT-D therapy and developed sustained torsades de pointes (TdP) immediately after switching to biventricular pacing (BVP) mode. Here, TdP possibly developed owing to the change in the dispersion of repolarization of the left ventricle myocardium. The diagnosis and management of BVP-induced ventricular arrhythmia is discussed. |
10,364 | Fabry cardiomyopathy presenting with a high defibrillation threshold: A short case report. | Fabry disease is an X-linked recessive glycosphingolipid storage disorder caused by a deficiency of lysosomal enzyme α-galactosidase A. It is recognized that Fabry disease patients often have ventricular arrhythmias. Although the effectiveness of implantable cardioverter-defibrillator (ICD) therapy in patients with ventricular fibrillation is established, there is little evidence regarding ICD therapy for Fabry disease. Here, we report the case of patient with Fabry disease who was treated with an ICD and presented with high defibrillation thresholds. |
10,365 | Failure of communication and capture: The perils of temporary unipolar pacing system. | We present a case of a patient with pacemaker dependence secondary to complete heart block who developed loss of capture of her temporary pacemaker. Patient developed torsades de pointes then ventricular fibrillation, requiring CPR and external cardioversion. After patient was stabilized, it was noticed that loss of capture of pacemaker corresponded with nursing care, when the pulse generator was lifted off patient׳s chest wall, and that patient׳s temporary pacing system had been programmed to unipolar mode without knowledge of attending cardiologist. This case highlights the importance of communication ensuring all caregivers are aware of mode of the temporary pacing system. |
10,366 | Defibrillation lead placement using a transthoracic transatrial approach in a case without transvenous access due to lack of the right superior vena cava. | A 65-year-old woman with a history of syncope was diagnosed with hypertrophic cardiomyopathy. She had previously undergone mastectomy of the left breast owing to breast cancer. Holter electrocardiogram (ECG) and monitor ECG revealed sick sinus syndrome (Type II) and non-sustained ventricular tachycardia. Sustained ventricular tachycardia and ventricular fibrillation were induced in an electrophysiological study. Although the patient was eligible for treatment with a dual chamber implantable cardioverter defibrillator (ICD), venography revealed lack of the right superior vena cava (R-SVC). Lead placement from the left subclavian vein would have increased the risk of lymphedema owing to the patient׳s mastectomy history. Consequently, the defibrillation lead was placed in the right ventricle by direct puncture of the right auricle through the tricuspid valve. The atrial lead was sutured to the atrial wall, and the postoperative course was unremarkable. Defibrillation lead placement using a transthoracic transatrial approach can be an alternative method in cases where a transvenous approach for lead placement is not feasible. |
10,367 | QRS-ST-T triangulation with repolarization shortening as a precursor of sustained ventricular tachycardia during acute myocardial ischemia. | We present segments from a 24-hour 12-lead digital Holter recording in a 48-year-old man demonstrating transient ST elevations in the inferior leads that triggered sustained ventricular tachycardia/ventricular fibrillation (VT/VF) requiring cardioversion. The onset of VT was preceded by a gradual increase in the ST with marked QRS broadening that lacked distinction between the end of the QRS and the beginning of the ST (QRS-ST-T "triangulation"), and shortening of the QT interval not caused by an increased heart rate. This is a relatively rare documentation of the mechanisms immediately triggering sustained ventricular arrhythmias during acute myocardial ischemia obtained with 12-lead ECG. |
10,368 | Premature ventricular beats initiate recurrent ventricular fibrillation in early repolarization syndrome. | An early repolarization (ER) pattern on electrocardiography was historically considered a benign finding; however, this finding in the inferior and lateral leads has recently been associated with idiopathic ventricular fibrillation (VF). Here we describe a case of a 29-year-old man with an ER pattern, who experienced recurrent implantable cardioverter-defibrillator (ICD) shocks for ventricular tachycardia (VT) and VF. An ICD interrogation demonstrated how VF and VT were repeatedly initiated by closely coupled premature ventricular beats. |
10,369 | Evaluation of defibrillation safety and shock reduction in implantable cardioverter-defibrillator patients with increased time to detection: A randomized SANKS study. | The need for ways to minimize the number of implantable cardioverter-defibrillator (ICD) shocks is increasing owing to the risk of its adverse effects on life expectancy. Studies have shown that a longer detection time for ventricular tachyarrhythmia reduces the safety of therapies, in terms of syncope and mortality, but not substantially in terms of the success rate. We aimed to evaluate the effects of increased number of intervals to detect (NID) VF on the safety of ICD shock therapy and on the reduction of inappropriate shocks.</AbstractText>The present study was a prospective, multicenter, randomized, crossover study. Randomized VF induction testing with NID 18/24 or 30/40 was performed to compare the success rate of defibrillation with a 25-J shock and the time to detection. Inappropriate shock episodes were simulated retrospectively to evaluate a possibility of episodes avoidable at NID 24/32 and 30/40.</AbstractText>Thirty-one consecutive patients implanted with an ICD or cardiac resynchronization therapy-defibrillator (CRT-D) were enrolled in this study. The success rate of defibrillation was 100% in both NID groups at the first shock. The time from VF induction to detection showed a significant increase in the NID 30/40 group (6.16±1.29 s vs. 9.00±1.31 s, p<0.001). Among the 120 patients implanted with an ICD or CRT-D, 10 experienced 32 inappropriate shock episodes. The inappropriate shock reduction rate was 53.1% and 62.5% with NID 24/32 and 30/40, respectively.</AbstractText>The findings of this SANKS study suggest that VF NID 30/40 does not compromise the safety of ICD shock therapy, while decreasing the number of inappropriate shocks.</AbstractText> |
10,370 | A case of short-coupled premature ventricular beat-induced ventricular fibrillation with early repolarization in the inferolateral leads. | This case report describes a 19-year-old man with early repolarization (ER) in the inferolateral leads and a normal QT interval who survived a cardiac arrest that was likely related to polymorphic ventricular tachycardia (VT). Electrocardiograms (ECGs) also showed unifocal premature ventricular beats (PVBs) with a relatively narrow QRS duration. A Holter ECG documented occasional short-coupled PVBs following non-sustained VTs. Pharmacological stress testing was also performed to assess the effects of anti-arrhythmic drugs on ER (the J wave) and PVBs. We performed successful radiofrequency catheter ablation to prevent the recurrence of ventricular fibrillation after cardioverter-defibrillator implantation. |
10,371 | Long-term outcomes of catheter ablation of ventricular tachycardia in patients with structural heart disease. | Catheter ablation of ventricular tachycardia (VT) is feasible. However, the long-term outcomes for different underlying diseases have not been well defined.</AbstractText>Eighty-eight consecutive patients who underwent catheter ablation of VT using a three-dimensional mapping system were analyzed. The primary endpoint was any VT or ventricular fibrillation (VF) recurrence. Secondary endpoints were a composite of death or any VT/VF recurrence. Underlying heart diseases were remote myocardial infarction (remote MI) in 51 patients and non-ischemic cardiomyopathy in 37 (arrhythmogenic right ventricular cardiomyopathy [ARVC] in 18 patients, and dilated cardiomyopathy [NIDCM] in 19).</AbstractText>Acute success was achieved in 82 of 88 (93%) patients. During a follow-up period of 39.2±4.6 months, VT recurred in 26 of 87 (30%), and VT/VF recurrence or death occurred in 39 of 87 (45%) patients. ARVC had better outcomes than NIDCM for the primary (p<0.05) and secondary endpoints (p<0.05). Remote MI-VT revealed a midrange outcome.</AbstractText>The long-term outcomes after catheter ablation of VT varied according to the underlying heart disease. ARVC-VT ablation was associated with better long-term prognosis than NIDCM. Remote MI-VT demonstrated a midrange outcome.</AbstractText> |
10,372 | Successful ECMO-cardiopulmonary resuscitation with the associated post-arrest cardiac dysfunction as demonstrated by MRI. | Veno-arterial extracorporeal membrane oxygenation (ECMO-CPR) is a life-saving rescue for selected patients when standard cardiopulmonary resuscitation fails. The use is increasing although the treatment modality is not fully established. Resuscitated patients typically develop a detrimental early post-arrest cardiac dysfunction that also deserves main emphasis. The present study investigates an ECMO-CPR strategy in pigs and assesses early post-arrest left ventricular function in detail. We hypothesised that a significant dysfunction could be demonstrated with this model using magnetic resonance imaging (MRI), not previously used early post-arrest.</AbstractText>In eight anaesthetised pigs, a 15-min ventricular fibrillation was resuscitated by an ECMO-CPR strategy of 150-min veno-arterial ECMO aiming at high blood flow rate and pharmacologically sustained aortic blood pressure and pulse pressure of 50 and 15 mmHg, respectively. Pre-arrest cardiac MRI and haemodynamic measurements of left ventricular function were compared to measurements performed 300-min post-arrest.</AbstractText>All animals were successfully resuscitated, weaned from the ECMO circuit, and haemodynamically stabilised post-arrest. Cardiac output was maintained by an increased heart rate post-arrest, but left ventricular ejection fraction and stroke volume were decreased by approximately 50 %. Systolic circumferential strain and mitral annular plane systolic excursion as well as the left ventricular wall thickening were reduced by approximately 50-70 % post-arrest. The diastolic function variables measured were unchanged.</AbstractText>The present animal study demonstrates a successful ECMO-CPR strategy resuscitating long-lasting cardiac arrest with adequate post-arrest haemodynamic stability. The associated severe systolic left ventricular dysfunction could be charted in detail by MRI, a valuable tool for future cardiac outcome assessments in resuscitation research.</AbstractText>Institutional protocol number: FOTS 4611/13 .</AbstractText> |
10,373 | Successful extraction of right ventricular lead remnants using the FlexCath® steerable sheath. | In patients undergoing laser lead extraction, incomplete or failed lead removal occur in over 3 % of leads. Because the current available tools have limitations in reaching the right ventricle (RV), the procedure becomes challenging when the lead breaks and its fragments remain lodged in the RV. We describe two cases in which the FlexCath® steerable sheath, normally used in cryoballoon catheter ablation for atrial fibrillation, was useful in directing a bioptome to right ventricular lead fragments and thus allowing for complete lead extraction. |
10,374 | Malignant conversion of benign right ventricular outflow track ventricular tachycardia 18 years post-ablation. | This case report describes the rare phenomenon of malignant conversion of benign right ventricular outflow tract ventricular tachycardia into idiopathic ventricular fibrillation 18 years after successful ablation, in the absence of any type of heart disease. We review the current literature looking at predictors for this event, with the conclusion that there are no reliable risk predictors available. Until clear guidelines exist, we suggest patients be informed and monitored for the possibility of "malignant conversion" following ablation for benign idiopathic outflow tract ventricular tachycardia. |
10,375 | NOS1AP Polymorphisms Modify QTc Interval Duration But Not Cardiac Arrest Risk in Hypertrophic Cardiomyopathy. | The accurate prediction of the risk of sudden cardiac death (SCD) in hypertrophic cardiomyopathy (HCM) remains elusive. Corrected QT interval (QTc) duration is a known risk factor in various cardiac conditions. Single nucleotide polymorphisms (SNPs) have been linked to QTc length, and to SCD. Here we investigated the role of 21 candidate SNPs in QTc duration and SCD events in patients with HCM.</AbstractText>This HCM registry-based study included patients with an ECG, medical history, first SCD event data, and DNA available. Each individual SNP was assessed using logistic regression for associations with 2 outcomes: a prolonged QTc ( ≥440 milliseconds), and first SCD event (SCD, resuscitated cardiac arrest, and appropriate implantable cardioverter defibrillator (ICD) shock for ventricular fibrillation/ventricular tachycardia (VF/VT). In 272 HCM patients, there were 31 SCD events (8 SCD, 9 resuscitated cardiac arrest, 14 ICD shocks for VF/VT; 11%). A QTc ≥ 500 milliseconds was associated with SCD events on multivariate analysis (odds ratio [OR] = 4.0, 95% confidence interval [CI], 1.19-12.02, P = 0.016). In 228 Caucasian patients, 2 SNPs in the NOS1AP gene (rs10494366 and rs12143842) were associated with a prolonged QTc after correction for multiple testing. This remained significant after adjustment for current age, sex, and ≥1 SCD risk factor (OR 1.59 per copy of the minor allele, 95% CI 1.08-2.39, P = 0.022, and OR 1.63, 95% CI 1.09-2.49, P = 0.020, respectively). No SNPs were directly associated with SCD events.</AbstractText>SNPs in the NOS1AP gene influence QTc interval duration but we have not demonstrated a direct association with the risk of SCD.</AbstractText>© 2015 Wiley Periodicals, Inc.</CopyrightInformation> |
10,376 | Renal function impairment predicts mortality in patients with chronic heart failure treated with resynchronization therapy. | The use of cardiac resynchronization therapy (CRT) and implantable cardioverter- defibrillator (ICD) for advanced heart failure (HF) is increasing. Renal dysfunction is a common condition in HF which is associated with a worse survival. The study aims at identifying in patients with advanced HF treated with CRT the effect of baseline glomerular filtration rate (GFR), GFR improvement and left ventricular ejection fraction (LVEF) change, after 6-months of CRT implant, on survival.</AbstractText>The study population consisted of 375 advanced HF patients who received a CRT between 1999 and 2009, of these 277 received also an ICD implant. Clinical characteristics (New York Heart Association [NYHA] functional class, ischemic vs. non-ischemic etiology, atrial fibrillation, diabetes, hypertension, LVEF, QRS duration and GFR were recorded. The use of common used drugs was evaluated. Cox proportional hazards analysis was calculated in order to evaluate variables associated to mortality.</AbstractText>During a median follow-up of 43.0 months, 93 (24.8%) patients died. Patients deceased during the study had at baseline higher NYHA class and lower LVEF and GFR. In Cox regression analysis, GFR predicts long-term mortality (hazard ratio [HR] 0.983; 95% confidence interval [CI] 0.969-0.998; p = 0.023) independently from the effect of others covariates. In addition, a positive GFR improvement 6 months after CRT implant is significantly associated with a lower hazard of mortality (for each 10 mL/min of GFR improvement HR 0.86; 95% CI 0.75-0.99; p = 0.038).</AbstractText>GFR is a significant predictor of mortality in advanced HF patients who received CRT. A GFR improvement 6 months after CRT implant is significantly associated with a lower hazard of mortality.</AbstractText> |
10,377 | Ventricular fibrillation waveform characteristics differ according to the presence of a previous myocardial infarction: A surface ECG study in ICD-patients. | Characteristics of the ventricular fibrillation (VF) waveform reflect arrest duration and have been incorporated in studies on algorithms to guide resuscitative interventions. Findings in animals indicate that VF characteristics are also affected by the presence of a previous myocardial infarction (MI). As studies in humans are scarce, we assessed the impact of a previous MI on VF characteristics in ICD-patients.</AbstractText>Prospective cohort of ICD-patients (n=190) with defibrillation testing at the Radboudumc (2010-2013). VF characteristics of the 12-lead surface ECG were compared between three groups: patients without a history of MI (n=88), with a previous anterior (n=47) and a previous inferior MI (n=55).</AbstractText>As compared to each of the other groups, the mean amplitude and amplitude spectrum area were lower, for an anterior MI in lead V3 and for an inferior MI in leads II and aVF. Across the three groups, the bandwidth was broader in the leads corresponding with the infarct localisation. In contrast, the dominant and median frequencies only differed between previous anterior MI and no history of MI, being lower in the former.</AbstractText>The VF waveform is affected by the presence of a previous MI. Amplitude-related measures were lower and VF was less organised in the ECG-lead(s) adjacent to the area of infarction. Although VF characteristics of the surface ECG have so far primarily been considered a proxy for arrest duration and metabolic state, our findings question this paradigm and may provide additional insights into the future potential of VF-guided resuscitative interventions.</AbstractText>Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
10,378 | Noninvasive characterization of atrioventricular conduction in patients with atrial fibrillation. | The atrioventricular (AV) node plays a fundamental role in patients with atrial fibrillation (AF), acting as a filter to the numerous irregular atrial impulses which bombard the node. A phenomenological approach to better understand AV nodal electrophysiology is to analyze the ventricular response with respect to irregularity. In different cohorts of AF patients, such analysis has been performed with the aim to evaluate the association between ventricular response characteristics and long-term clinical outcome and to determine whether irregularity is affected by rate-control drugs. Another approach to studying AV nodal characteristics is to employ a mathematical model which accounts for the refractory periods of the two AV nodal pathways. With atrial fibrillatory rate and RR intervals as input, the model has been considered for analyzing data during (i) rest and head-up tilt test, (ii) tecadenoson and esmolol, and (iii) rate-control drugs. The present paper provides an overview of our recent work on the characterization and assessment of AV nodal conduction using these two approaches. |
10,379 | The postoperative complication for adenocarcinoma of esophagogastric junction. | The purpose of this study was to evaluate the postoperative complications for patients with adenocarcinoma of esophagogastric junction.</AbstractText>Two hundred and eighty subjects with adenocarcinoma of esophagogastric junction who received operation were retrospectively analyzed from June 2006 to December 2010 in the Department of Oncology of First Affiliated Hospital of Bengbu Medical College, Bengbu, China. The postoperative complication such as ventricular premature beat, atrial fibrillation, supraventricular tachycardia, heart failure, pulmonary infection, pulmonary atelectasis, respiratory failure, bronchospasm, anastomotic leakage, gastroplegia, pleural infection, and cerebral accident were reviewed and recorded by to doctors. Moreover, the correlation between clinical characteristics and postoperative complication was analyzed by statistical methods.</AbstractText>A total of 70 complications were found for the included 280 cases of adenocarcinoma of esophagogastric junction with general incidence of 25%. For the relationship between clinical characteristics and postoperative complication analysis, no significant association of gender, age, operation time, operative approach, tumor differentiation, and clinical states was found with the postoperative complications (P > 0.05); but the complication rate in patients with basic disease of heart and lung was significant than the patients without this kind of disease (P < 0.05).</AbstractText>The positive operative complications for patients with adenocarcinoma of esophagogastric junction were relative high. Moreover, basic heart and lung diseases can increase the risk of developing positive operative complications.</AbstractText> |
10,380 | [Differential diagnosis of tachycardia with a broad QRS-complex]. | The electrocardiographic (ECG) differential diagnosis of tachycardia with a broad QRS complex (BCT) represents a challenge for physicians but is important for adequate treatment and risk evaluation. Differentiated algorithms have been established and can increase the specificity of the diagnosis in individual patients but are often hampered by complexity and yield a pragmatic ECG approach.</AbstractText>Irregular BCTs (irregular R-R distances) despite the patient being hemodynamically stable are almost always due to atrial fibrillation with bundle branch block (pre-existing or functional) or conduction via accessory pathways. In contrast, sustained polymorphic ventricular tachycardia (VT) is always associated with hemodynamic collapse. In regular BCT the following mechanisms must be differentiated: (1) VT, (2) supraventricular tachycardia (SVT) with bundle branch block or (3) SVT with pre-excitation via accessory pathways, e.g. Wolff-Parkinson-White (WPW) syndrome. The presence of an underlying structural heart disease, specifically a history of myocardial infarction is suggestive of VT. For a differentiated analysis in hemodynamically stable patients a 12-lead ECG is essential.</AbstractText>Identification of signs of atrioventricular (AV) dissociation or a negative precordial concordance of QRS are indicative of VT. In V1 positive BCTs a positive precordial concordance, QRS width > 140 ms, superiorly directed QRS axis, monophasic or biphasic QRS complexes in V1 and deep S wave in V6 are indications of a VT. In V1 negative BCTs, QRS width > 160 ms, right-sided QRS axis, broad R peak (> 40 ms) in V1/V2, slurred S downstroke in V1/V2 and any Q peak in V6 are all indications of VT as the mechanism.</AbstractText> |
10,381 | Clinical characteristics and management of hospitalized and ambulatory patients with heart failure-results from ESC heart failure long-term registry-Egyptian cohort. | Our aim is to describe the clinical characteristics and management of patients hospitalized with acute heart failure (HHF) and ambulatory patients with chronic heart failure (CHF) in Egypt and compare them with heart failure (HF) patients from other countries in the European Society of Cardiology-Heart Failure (ESC-HF) registry.</AbstractText>The ESC-HF Long-term Registry is a prospective, multi-centre, observational study of patients presenting to cardiology centres in member countries of the ESC. From April 2011 to February 2014, a total of 2145 patients with HF were recruited from 20 centres all over Egypt. Of these patients, 1475 (68.8%) were hospitalized with HHF, while 670 (31.2%) had CHF. Less than one-third (32.1%) of all patients were females. HHF patients {median age of 61 years [interquartile range (IQR), 53-69]} were older than CHF patients [median age of 57 years (IQR,46-64)]; P < 0.0001. They had more diabetes mellitus (45.4% vs. 31.8%; P < 0.0001). Left ventricular ejection fraction > 45% was present in 22% of HHF vs. 25.6% of CHF (P = 0.17). Atrial fibrillation existed in about a quarter of all patients (24.5%). Ischaemic heart disease was the main cause of HF in Egyptian patients. All-cause in-hospital mortality was 5%. Egyptian patients presented at a much earlier age than in other regions in the registry. They had more diabetes mellitus. Atrial fibrillation prevalence was remarkably lower. Other co-morbidities (renal dysfunction, stroke, and peripheral arterial disease) occurred less frequently.</AbstractText>Patients in the Egyptian cohort exhibited distinct features from HF patients in other countries in the ESC-HF Long-term Registry.</AbstractText>© 2015 The Authors. ESC Heart Failure published by John Wiley & Sons Ltd on behalf of the European Society of Cardiology.</CopyrightInformation> |
10,382 | ACE Inhibitor Delapril Prevents Ca(2+)-Dependent Blunting of IK1 and Ventricular Arrhythmia in Ischemic Heart Disease. | Angiotensin-converting enzyme inhibitors (ACE-I) improve clinical outcome in patients with myocardial infarction (MI) and chronic heart failure. We investigated potential anti-arrhythmic (AA) benefits in a mouse model of ischemic HF. We hypothesized that normalization of diastolic calcium (Ca(2+)) by ACE-I may prevent Ca(2+)-dependent reduction of inward rectifying K(+) current (IK1) and occurrence of arrhythmias after MI. Mice were randomly assigned to three groups: Sham, MI, and MI-D (6 weeks of treatment with ACE-I delapril started 24h after MI). Electrophysiological analyses showed that delapril attenuates MI-induced prolongations of electrocardiogram parameters (QRS complex, QT, QTc intervals) and conduction time from His bundle to ventricular activation. Delapril improved the sympatho-vagal balance (LF/HF) and reduced atrio-ventricular blocks and ventricular arrhythmia. Investigations in cardiomyocytes showed that delapril prevented the decrease of IK1 measured by patch-clamp technique. IK1 reduction was related to intracellular Ca(2+) overload. This reduction was not observed when intracellular free-Ca(2+) was maintained low. Conversely, increasing intracellular free-Ca(2+) in Sham following application of SERCA2a inhibitor thapsigargin reduced IK1. Thapsigargin had no effect in MI animals and abolished the benefits of delapril on IK1 in MI-D mice. Delapril prevented both the prolongation of action potential late repolarization and the depolarization of resting membrane potential, two phenomena known to trigger abnormal electrical activities, promoted by MI. In conclusion, early chronic therapy with delapril after MI prevented Ca(2+)-dependent reduction of IK1. This mechanism may significantly contribute to the antiarrhythmic benefits of ACE-I in patients at risk for sudden cardiac death. |
10,383 | Safety of American Heart Association-recommended minimum exercise for desmosomal mutation carriers. | Endurance exercise is associated with adverse outcomes in patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C). Exercise recommendations for family members remain undetermined.</AbstractText>The purposes of this study were to determine if (1) endurance exercise (Bethesda class C) and exercise intensity (metabolic equivalent hours per year [MET-Hr/year]) increase the likelihood of fulfilling 2010 Task Force Criteria and ventricular arrhythmias/implantable cardioverter-defibrillator shock (ventricular tachycardia/ventricular fibrillation [VT/VF]), and (2) exercise restriction to the American Heart Association (AHA)-recommended minimum for healthy adults is associated with favorable outcomes of at-risk family members.</AbstractText>Twenty-eight family members of 10 probands inheriting a PKP2 mutation were interviewed about exercise from age 10. Exercise threshold to maintain overall health was based on the 2007 AHA guidelines of a minimum 390 to 650 MET-Hr/year.</AbstractText>After adjustment for age, sex, and family membership, both participation in endurance athletics (odds ratio [OR] 7.4, P = .03) and higher-intensity exercise (OR = 4.2, P = .004) were associated with diagnosis (n = 13). Endurance athletes were also significantly more likely to develop VT/VF (n = 6, P = .02). Family members who restricted exercise at or below the upper bound of the AHA goal (≤650 MET-Hr/year) were significantly less likely to be diagnosed (OR = 0.07, P = .002) and had no VT/VF. At diagnosis and first VT/VF, family members had accumulated 2.8-fold (P = .002) and 3.5-fold (P = .03), respectively, greater MET-Hr exercise than the AHA-recommended minimum. Those who developed VT/VF had performed particularly high-intensity exercise in adolescence compared to unaffected family members (age 10-14: P = .04; age 14-19: P = .02).</AbstractText>The results of this study suggest restricting unaffected desmosomal mutation carriers from endurance and high-intensity athletics but potentially not from AHA-recommended minimum levels of exercise for healthy adults.</AbstractText>Copyright © 2016 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
10,384 | Right Parasternal Electrode Configuration Converts a Failed Electrocardiographic Screening to a Pass for Subcutaneous Implantable Cardioverter-Defibrillator Implantation. | Pre-operative electrocardiographic (ECG) screening before subcutaneous implantable cardioverter-defibrillator (SICD) implantation is essential to prevent T-wave oversensing and inappropriate shocks. The failure rate of ECG screening was reported to be up to 8% when only two body positions were tested.</AbstractText>Three subcutaneous ECG vectors represented by lead I, II and III were obtained in standing, supine, sitting and squatting positions. A patient qualified if the ECG in any same lead passed in all four positions. We report a 31-year-old man with idiopathic ventricular fibrillation who failed ECG screening for SICD implantation with the conventional left parasternal electrode (LPS) configuration in all three subcutaneous ECG vectors. Right parasternal electrode (RPS) configuration with left arm and right arm ECG electrodes positioned 1cm lateral to right sternal border was attempted for screening.</AbstractText>The amplitude of the QRS complex was significantly larger in the RPS compared to the LPS configuration in lead III and the patient passed the ECG screening in four body positions. He underwent successful SICD implantation with RPS approach with appropriate sensing both during the procedure and exercise treadmill test four weeks later. Ventricular fibrillation was successfully converted with 65J standard polarity shock during the procedure and no ICD shock was experienced by the patient on six-month follow-up.</AbstractText>RPS configuration may be considered in patients who fail the ECG screening with the conventional LPS approach for SICD implantation.</AbstractText>Copyright © 2015 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.</CopyrightInformation> |
10,385 | Classification of cardiac rhythm using heart rate dynamical measures: validation in MIT-BIH databases. | Identification of atrial fibrillation (AF) is a clinical imperative. Heartbeat interval time series are increasingly available from personal monitors, allowing new opportunity for AF diagnosis.</AbstractText>Previously, we devised numerical algorithms for identification of normal sinus rhythm (NSR), AF, and SR with frequent ectopy using dynamical measures of heart rate. Here, we wished to validate them in the canonical MIT-BIH ECG databases.</AbstractText>We tested algorithms on the NSR, AF and arrhythmia databases.</AbstractText>When the databases were combined, the positive predictive value of the new algorithms exceeded 95% for NSR and AF, and was 40% for SR with ectopy. Further, dynamical measures did not distinguish atrial from ventricular ectopy. Inspection of individual 24hour records showed good correlation of observed and predicted rhythms.</AbstractText>Heart rate dynamical measures are effective ingredients in numerical algorithms to classify cardiac rhythm from the heartbeat intervals time series alone.</AbstractText>Copyright © 2015 Elsevier Inc. All rights reserved.</CopyrightInformation> |
10,386 | [Detection of Signs of Thrombus Formation in Patients With Typical Atrial flutter]. | to assess rate of detection of markers of thrombi formation and to determine whether transthoracic echocardiography data or clinical characteristics predict severe left atrial appendage [LAA] dysfunction (low LAA velocity, severe spontaneous echo contrast [SEC], LAA thrombus) in patients with typical atrial flutter (AFI).</AbstractText>Consecutive 406 patients (299 with atrial fibrillation [AFib] and 107 with AFI) underwent transesophageal echocardiography before cardioversion. Mean age was 59.3 years, mean CHA2DS2-VASc score--1.86, mean LAA velocity--37.02 cm/s.</AbstractText>Compared with patients with AF those with AFI had lower rate of detection of markers of thrombi formation (p < 0.05). Among patients with AFI 1.8% had SEC grade 4+, 7.4%--LAA velocity ≤ 25 cm/s. LAA thrombus was found in 2.8 and 8.1% of patients with AFI and AFib, respectively. Prevalence of thrombi in left ventricular (LV) cavity was significantly higher in patients with AFI (3.13 vs. 0.3% in patients with AFib, p = 0.02). In patients with AFI systolic LV dysfunction was the main and ost significant predictor of severe LAA dysfunction and presence LV thrombus.</AbstractText>AFI associated high risk of embolic events is primarily determined by its adverse effect on LV function.</AbstractText> |
10,387 | Pinocembrin reduces cardiac arrhythmia and infarct size in rats subjected to acute myocardial ischemia/reperfusion. | Oxidative stress plays an important role in the pathogenesis of ischemia/reperfusion (I/R) injury induced by cardiac dysfunction. Pinocembrin (5,7-dihydroxyflavanone) is a flavonoid found in propolis and in rhizomes of fingerroot (Boesenbergia pandurata) that is reported to have pharmacological properties including antimicrobial, antioxidant, and anti-inflammatory activities. The cardioprotective effects of pinocembrin in an I/R model were investigated in this study. Male Wistar rats (n = 20) were randomly divided into 2 groups to receive either pinocembrin (30 mg/kg body weight) or the vehicle intravenously. Thirty minutes later, the left anterior descending coronary artery of each rat was ligated for 30 min, and then reperfusion was allowed for 120 min. Cardiac function improved in the pinocembrin-treated group: the time to first ventricular fibrillation (VF) was significantly longer in the treated group (550 ± 54 s) than in the vehicle-only control group (330 ± 27 s) (p < 0.05). VF incidence and arrhythmia score were lower and infarcts were 49% smaller in the pinocembrin-treated group than in the control group (p < 0.05). In the pinocembrin-treated group, malondialdehyde levels and Bax/Bcl-2 ratios decreased, and the ratio of phosphorylated connexin 43 (phospho-Cx43) to total Cx43 increased in infarcted tissues compared with the non-infarcted area (p < 0.05). Pinocembrin exhibited cardioprotective effects during I/R, evidenced by improved cardiac function, fewer arrhythmias, and smaller infarcts in treated hearts than in controls. These benefits may be due to pinocembrin's antiapoptotic and anti-oxidative stress effects and its ability to increase the phosphorylation of Cx43 in ischemic myocardium. |
10,388 | [Factors predisposing to the reprogramming of implantable cardioverter-defibrillators and the causes of changes in pharmacotherapy in patients with dilated cardiomyopathy for primary prevention of sudden cardiac death]. | Ambulatory care of patients with implantable cardioverter-defibrillator (ICD) involves regular follow-up visit, where a decision on reprogramming of the device and modification of pharmacotherapy is made.</AbstractText>The aim of the study was the assessment of frequency and reasons of reprogramming and pharmacotherapy changes in patients with dilated cardiomyopathy with an ICD implanted due to primary prevention of sudden cardiac death (SCD).</AbstractText>The study included 143 consecutive patients with an ICD implanted in 2010-2011. The inclusion criteria were: left ventricle ejection fraction (LVEF)≤35%, New York Heart Association (NYHA) Class≥II, implantation due to primary prevention of SCD. All ambulatory visits in outpatient department were investigated retrospectively. The following variables were analyzed: age, gender, presence of coronary artery disease (CAD) and atrial fibrillation (AF), LVEF, NYHA class, presence of interventions, reprogramming and pharmacotherapy changes.</AbstractText>The most common changes in ICD parameters were modification of detection and therapy of ventricular arrhythmias. Modification of pharmacotherapy were most often referred to B-blocker and cardiac glycosides. Patients with AF had more often parameters of bradycardia pacing changed (p=0,016). There was a significant correlation between number of interventions and total number of reprogramming (r=0,3 p<0,05). A negative correlation was found between LVEF and number of reprogramming of detection of ventricular tachyarrhythmia (r=-0,18 p<0,05) and between LVEF and number of interventions (r=-0,2, p<0,05). Patients with interventions and patients AF had more pharmacotherapy changes (82 vs 29, p<0,001 and 59 vs 52, p<0,01 respectively). A significant correlation was found between number of interventions and total number of pharmacotherapy changes (r=0,5 p<0,05) and between number of interventions and modification of pharmacotherapy with B-blocker, cardiac glycosides and introduction of amiodarone therapy (r=0,47; r=0,30; r=0,32 respectively, p<0,05).</AbstractText>Patients with AF had more changes in ICD parameters, pacing parameters and pharmacotherapy. Patients with lower LVEF had more interventions and more changes in detection of ventricular tachyarrhythmia.</AbstractText>© 2015 MEDPRESS.</CopyrightInformation> |
10,389 | Symptom assessment and exercise impairment in surgical decision making in hypertrophic obstructive cardiomyopathy: Relationship to outcomes. | We sought to assess the long-term outcomes in patients with hypertrophic cardiomyopathy and severe left ventricular outflow tract obstruction, in whom the decision regarding surgery (vs conservative management) was based on assessment of symptoms or exercise capacity.</AbstractText>This was an observational study of 1530 patients with hypertrophic cardiomyopathy (aged 50 ± 13 years, 63% were men) with severe left ventricular outflow tract obstruction (excluding those aged <18 years, with left ventricular ejection fraction <50%, and with left ventricular outflow tract gradient <30 mm Hg). A composite end point of death (excluding noncardiac causes) and/or implantable defibrillator discharge was assessed.</AbstractText>Coronary artery disease, family history of hypertrophic cardiomyopathy, and syncope were present in 15%, 17%, and 18% of patients, respectively, whereas 73% patients were in New York Heart Association class II or greater. Mean left ventricular ejection fraction, basal septal thickness, and left ventricular outflow tract gradient (resting or provocable) were 62% ± 5%, 2.2 ± 1 cm, and 101 ± 39 mm Hg, respectively. A total of 858 patients (56%) underwent exercise echocardiography, of whom 503 (59%) had exercise capacity impairment. At 8.1 ± 6 years, 990 patients (65%) underwent surgical relief of left ventricular outflow tract obstruction, and 540 patients (35%) did not. There were 156 events (10%) (134 deaths), with 0% 30-day mortality in the surgical group. On multivariable Cox proportional hazard analysis, increasing age (hazard ratio [HR], 1.20), coronary artery disease (HR, 1.68), worse New York Heart Association class (HR, 1.46), and atrial fibrillation (HR, 1.90) predicted higher events, whereas surgery (time-dependent covariate HR, 0.57) was associated with improved event-free survival (all P < .01).</AbstractText>In patients with hypertrophic cardiomyopathy and severe left ventricular outflow tract obstruction, in whom the decision regarding surgery was based on the presence of intractable symptoms and impaired exercise capacity, surgery was associated with significant improvement in long-term composite outcomes.</AbstractText>Copyright © 2015 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
10,390 | Gender Differences in Patients with Takotsubo Cardiomyopathy: Multi-Center Registry from Tokyo CCU Network. | The clinical features of gender differences in takotsubo cardiomyopathy (TC) remain to be determined. The aim of this study was to evaluate the differences in clinical characteristics of male and female patients with TC.</AbstractText>We obtained the clinical information of 368 patients diagnosed with TC (84 male, 284 female) from the Tokyo CCU Network database collected from 1 January 2010 to 31 December 2012; the Network is comprised of 71 cardiovascular centers in the Tokyo (Japan) metropolitan area. We attempted to characterize clinical differences during hospitalization, comparing male and female patients with TC.</AbstractText>There were no significant differences in apical ballooning type, median echocardiography ejection fraction, serious ventricular arrhythmias (such as ventricular tachycardia or fibrillation), or cardiovascular death between male and female patients. Male patients were younger than female patients (median age at hospitalization for male patients was 72 years vs. 76 years for female patients; p = 0.040). Prior physical stress was more common in male than female patients (50.0% vs.31.3%; p = 0.002), while emotional stress was more common in female patients (19.0% vs. 31.0%; p = 0.039). Severe pump failure (defined as Killip Class > III) (20.2% vs. 10.6%; p = 0.020) and cardiopulmonary supportive therapies (28.6% vs. 12.7%, p < 0.001) were more common in male than female patients. Multivariate analysis revealed that male gender (odds ratio = 4.32, 95% CI = 1.41-13.6, p = 0.011) was an independent predictor of adverse composite cardiac events, including cardiovascular death, severe pump failure, and serious ventricular arrhythmia.</AbstractText>Cardiac complications in our dataset appeared to be more common in male than female patients with TC during their hospitalization. Further investigation is required to clarify the underlying mechanisms responsible for the observed gender differences.</AbstractText> |
10,391 | Nifekalant Hydrochloride and Amiodarone Hydrochloride Result in Similar Improvements for 24-Hour Survival in Cardiopulmonary Arrest Patients: The SOS-KANTO 2012 Study. | Amiodarone (AMD), nifekalant (NIF), and lidocaine (LID) hydrochlorides are widely used for ventricular tachycardia/fibrillation (VT/VF). This study retrospectively investigated the NIF potency and the differential effects of 2 initial AMD doses (≤150 mg or 300 mg) in the Japanese SOS-KANTO 2012 study population.</AbstractText>From 16,164 out-of-hospital cardiac arrest cases, 500 adult patients using a single antiarrhythmic drug for shock-resistant VT/VF were enrolled and categorized into 4 groups (73 LID, 47 NIF, 173 AMD-≤150, and 207 AMD-300). Multivariate analyses evaluated the outcomes of NIF, AMD-≤150, or AMD-300 groups versus LID group. Odds ratios (ORs) for survival to admission were 3.21 [95% confidence interval (CI): 1.38-7.44, P < 0.01] in NIF and 3.09 (95% CI: 1.55-6.16, P < 0.01) in AMD-≤150 groups and significantly higher than those of the LID group. However, the OR was 1.78 (95% CI: 0.90-3.51, P = 0.10) in AMD-300 group and was not significant than LID group. ORs for 24-hour survival were 6.68 in NIF, 4.86 in AMD-≤150, and 2.97 in AMD-300, being significantly higher in these groups.</AbstractText>NIF and AMD result in similar improvements for 24-hour survival in cardiopulmonary arrest patients, and this suggest the necessity of a randomized control study.</AbstractText> |
10,392 | Visually guided pulmonary vein isolation in patients with persistent atrial fibrillation. | The role of balloon catheters in patients with persistent forms of atrial fibrillation (AF) remains ill defined. We therefore sought to assess the safety and efficacy of a laser balloon (LB)-guided pulmonary vein isolation (PVI) in consecutive all-comers with persistent AF.</AbstractText>All patients undergoing an LB-guided PVI procedure for persistent AF between January 2011 and December 2012 were matched to patients undergoing circumferential PVI using irrigated radiofrequency (RF) current ablation for date of procedure, age, gender, AF duration, left atrial (LA) size, and left ventricular ejection fraction. The primary endpoint was freedom from AF between 90 and 365 days post-ablation after a single procedure. Eighty patients (mean age 66 ± 9; 71% male) with a median (Q1-Q3) AF episode duration of 2 (1-3) months underwent successful PVI in the two groups. The primary endpoint of 1-year single procedure AF/atrial tachycardia (AT) recurrences was reached by 11/40 (27.5%) patients in the LB group and in 9/40 (22.5%) patients in the RF group (P = 0.87). During a mean follow-up of 517 ± 170 days, 13 (32.5%) and 16 (40%) patients in the LB and RF groups, respectively, experienced AF/AT recurrences (P = 0.64). Procedural complications occurred in one patient in the LB group and in six patients in the RF group.</AbstractText>A subset of patients with drug-refractory persistent AF of short duration benefit from pure PVI without additional substrate modification. A LB-based strategy showed similar outcomes as an irrigated RF-guided circumferential PVI and may be considered an alternative option for the index ablation.</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> |
10,393 | Permanent pacemaker implantation after aortic valve replacement: Long-term dependency or rhythm recovery? | Conduction disturbances requiring permanent pacemaker (PM) implantation occur in 3-12% of patients after aortic valve replacement (AVR). Our aim was to assess long-term PM dependency and its predictors in these patients.</AbstractText>We conducted a retrospective study of all consecutive patients undergoing permanent PM implantation after AVR between January 2004 and December 2010. Absence of sinus rhythm or atrial fibrillation with appropriate ventricular response at a pacing rate of 30 bpm for 10 s was defined as pacemaker dependency.</AbstractText>Ninety-one patients underwent permanent PM implantation and during follow-up (1026.6 ± 732.0 days) 64% of them did not recover rhythm. Age, conduction disorders on the preoperative ECG, negative chronotropic medication before surgery, cardiopulmonary bypass and aortic cross-clamp times did not influence rhythm recovery. In multivariate analysis, valvular disease etiology related to endocarditis, prosthetic dysfunction and bicuspid valve were associated with long-term PM dependency (OR 5.05; CI: 1.43-17.75).</AbstractText>The majority of patients undergoing permanent PM implantation after AVR did not recover from conduction disorders during follow-up. The etiology of valvular disease was an independent predictor of late PM dependence.</AbstractText>Copyright © 2014 Sociedade Portuguesa de Cardiologia. Published by Elsevier España. All rights reserved.</CopyrightInformation> |
10,394 | Pre-Implant Assessment For Optimal LV Lead Placement In CRT: ECG, ECHO, or MRI? | Cardiac resynchronization therapy (CRT) improves cardiac function in many patients with ventricular dyssynchrony. The optimal use of imaging for pre-implantation assessment remains a subject of debate. Here, we review the literature to date on the utility of echocardiography and cardiac MR, as well as conventional ECG, in choosing the best site for LV lead implantation. Prior to the use of imaging for pre-implantation evaluation, LV leads were placed empirically, based on average responses from population-level studies. Subsequently, patient-specific approaches have been used to maximize response. Both echocardiography and cardiac MR allow determination of areas of latest mechanical activation. Some studies have found improved response when pacing is applied at or near the site of latest mechanical activation. Similarly, both echocardiography and cardiac MR provide information about the location of any myocardial scar, which should be avoided when placing the LV lead due to variable conduction and high capture thresholds. Alternative approaches include targeting the region of latest electrical activation via measurement of the QLV interval and methods based on intraoperative hemodynamic measurements. Each of these modalities offers complementary insights into LV lead placement, so future directions include multimodality pre-implantation evaluation, studies of which are ongoing. Emerging technologies such as leadless implantable pacemakers may free implanting electrophysiologists from the constraints of the coronary sinus, making this information more useful and making non-response to CRT increasingly rare. |
10,395 | Atrial Flutter In A Tetralogy Of Fallot Operated Patient: Importance Of A Rapid And Curative Treatment. | A 51 male, affected by Tetralogy of Fallot, underwent a left Blalock-Taussig anastomosis at the age of two years and an aorto - right pulmonary artery tube graft when 8 years old. Complete surgical correction was performed at age 21 with closure of the ventricular septal defect and a large patch over the right outflow tract, shunts were discontinued. Then it was well up to 51 years old when he began to suffer shortness of breath with minimal exertion. with ECG evidence of supraventricular tachycardia. Suggestive signs of a typical atrial flutter led to early electrophysiological assesment and successful cavo-tricuspid isthmus ablation was successfully performed. . Echocardiographic and magnetic resonance imaging and ergospirometry provided complete informations on anatomic and hemodynamic conditions but no other interventional procedure was necessary. |
10,396 | Atrioventricular Junction Ablation In Atrial Fibrillation: Choosing The Right Patient And Pacing Device. | Atrial fibrillation (AF) is the most common cardiac arrhythmia and despite advancements in rhythm control through direct catheter ablation, maintaining sinus rhythm is not possible in a large proportion of AF patients, who therefore are subject to a rate control strategy only. Nonetheless, in some of these patients pharmacological rate control may be ineffective, often leaving the patient highly symptomatic and at risk of developing tachycardia-induced cardiomyopathy and heart failure (HF). Catheter ablation of the atrioventricular junction (AVJ) with subsequent permanent pacemaker implantation provides definite rate control and represents an attractive therapeutic option when pharmacological rate control is not achieved. In patients with reduced ventricular function, cardiac resynchronization therapy (CRT) should be considered over right ventricular apical (RVA) pacing in order to avoid the deleterious effects associated with a high amount of chronic RVA pacing. Another group of patients that may also benefit from AVJ ablation are HF patients with concomitant AF receiving CRT. In this patient cohort AVJ ablation ensures near 100% biventricular pacing, thus allowing optimization of the therapeutic effects of CRT. |
10,397 | Very Long-Term Results Of Atrial Fibrillation Ablation Confirm That This Therapy Is Really Effective. | Catheter ablation -in general- is a highly effective and "curative" intervention for a broad spectrum of supraventricular and ventricular arrhythmias. After a successful procedure eliminating a simple arrhythmia substrate, the recurrence rate is low and the short term success correlates well with the long term freedom from the arrhythmia. |
10,398 | Biological significance of miR-126 expression in atrial fibrillation and heart failure. | We investigated the biological significance of microRNA-126 (miR-126) expression in patients with atrial fibrillation (AF) and/or heart failure (HF) to examine the possible mechanism of miR-126-dependent AF and development of HF. A total of 103 patients were divided into three groups: AF group (18 men and 17 women, mean age: 65.62±12.72 years), HF group (17 men and 15 women, mean age: 63.95±19.71 years), and HF-AF group (20 men and 16 women, mean age: 66.56±14.37 years). Quantitative real-time PCR was used to measure relative miR-126 expression as calculated by the 2-ΔΔCt method. miR-126 was frequently downregulated in the 3 patient groups compared with controls. This reduction was significantly lower in permanent and persistent AF patients than in those with paroxysmal AF (P<0.05, t-test). Moreover, miR-126 expression was markedly lower in the HF-AF group compared with the AF and HF groups. The 3 patient groups had higher N-terminal prohormone brain natriuretic peptide (NT-proBNP) levels, lower left ventricular ejection fraction (LVEF), larger left atrial diameter, and higher cardiothoracic ratio compared with controls. There were significant differences in NT-proBNP levels and LVEF among the AF, HF, and HF-AF groups. Pearson correlation analysis showed that relative miR-126 expression was positively associated with LVEF, logarithm of NT-proBNP, left atrial diameter, cardiothoracic ratio, and age in HF-AF patients. Multiple linear regression analysis showed that miR-126 expression was positively correlated with LVEF, but negatively correlated with the logarithm of NT-pro BNP and the cardiothoracic ratio (all P<0.05). Serum miR-126 levels could serve as a potential candidate biomarker for evaluating the severity of AF and HF. However, to confirm these results, future studies with a larger and diverse patient population are necessary. |
10,399 | Incidence and risk factors for symptomatic heart failure after catheter ablation of atrial fibrillation and atrial flutter. | To determine the incidence and risk factors for development of symptomatic heart failure (HF) following catheter ablation for atrial fibrillation (AF) and atrial flutter.</AbstractText>We prospectively enrolled consecutive patients undergoing pulmonary vein isolation (PVI) or cavotricuspid isthmus (CTI) ablation between November 2013 and June 2014. Post-discharge symptoms were assessed via telephone follow-up and clinic visits. The primary outcome was symptomatic HF requiring treatment with new/increased diuretic dosing. Secondary outcomes were prolonged index hospitalization and readmission for HF ≤30 days. Univariate and multivariable logistic regressions were used to assess the relationship between patient/procedural characteristic and post-ablation HF. Among 111 PVI patients [median age 62.0 years; left ventricular ejection fraction (LVEF) 55%], 29 patients (26.1%) developed symptomatic HF, 6 patients (5.4%) required prolonged index hospitalization, and 8 patients (7.2%) were readmitted for HF. In univariate analyses, persistent AF [odds ratio (OR) 2.97, P = 0.02], AF at start of the procedure (OR 2.99, P = 0.01), additional ablation lines (OR 11.07, P < 0.0001), and final left atrial pressure (OR 1.10 per 1 mmHg increase, P = 0.02) were associated with HF development. Peri-procedural diuresis, net fluid balance, and LVEF were not correlated. In multivariable analyses, only additional ablation lines (ORadj 9.17, P = 0.007) were independently associated with post-ablation HF. Six patients (16.7%) developed HF after CTI ablation.</AbstractText>A 26.1% of patients undergoing PVI and 16.7% of patients undergoing CTI ablation developed symptomatic HF when prospectively and uniformly assessed. 12.6% of patients experienced prolonged index hospitalizations or readmission for management of HF within 1 week after PVI. Improved understanding of risk factors for post-ablation HF may be critical in developing strategies to address during AF ablation.</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> |
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