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19,800 | β-Blocker Therapy Prior to Admission for Acute Coronary Syndrome in Patients Without Heart Failure or Left Ventricular Dysfunction Improves In-Hospital and 12-Month Outcome: Results From the GULF-RACE 2 (Gulf Registry of Acute Coronary Events-2). | The prognostic impact of β-blockers (BB) in acute coronary syndrome (ACS) patients without heart failure (HF) or left ventricular dysfunction is controversial, especially in the postreperfusion era. We sought to determine whether a BB therapy before admission for ACS has a favorable in-hospital outcome in patients without HF, and whether they also reduce 12-month mortality if still prescribed on discharge.</AbstractText>The GULF-RACE 2 (Gulf Registry of Acute Coronary Events-2) is a prospective multicenter study of ACS in 6 Middle Eastern countries. We studied in-hospital cardiovascular events in patients hospitalized for ACS without HF in relation to BB on admission, and 1-year mortality in relation to BB on discharge. Among the 7903 participants, 7407 did not have HF, of whom 5937 (80.15%) patients were on BB. Patients on BB tended to be older and have more comorbidities. However, they had a lower risk of in-hospital mortality, mitral regurgitation, HF, cardiogenic shock, and ventricular tachycardia/ventricular fibrillation. Furthermore, 4208 patients were discharged alive and had an ejection fraction ≥40%. Among those, 84.1% had a BB prescription. At 12 months, they also had a reduced risk of mortality as compared with the non-BB group. Even after correcting for confounding factors in 2 different models, in-hospital and 12-month mortality risk was still lower in the BB group.</AbstractText>In this cohort of ACS, BB therapy before admission for ACS is associated with decreased in-hospital mortality and major cardiovascular events, and 1-year mortality in patients without HF or left ventricular dysfunction if still prescribed on discharge.</AbstractText>© 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.</CopyrightInformation> |
19,801 | The limited prognostic role of echocardiograms in short-term follow-up after acute decompensated heart failure: An analysis of the Korean Heart Failure (KorHF) Registry. | The prognostic values of the left ventricular ejection fraction (LVEF) and end-diastolic dimension (LVEDD) have primarily been shown among patients with chronic heart failure (HF), with little representation of patients with acute HF (AHF). Therefore, we investigated the value of these echocardiographic parameters in predicting clinical outcomes among patients in the Korean Heart Failure (KorHF) Registry.</AbstractText>The KorHF Registry consists of 3,200 patients who were hospitalized with AHF from 2005 to 2009. The Kaplan-Meier method was used to estimate survival and readmission, and differences were assessed using the log-rank test. Predictors of survival were identified using univariate and multivariate Cox proportional hazards regression analyses.</AbstractText>Echocardiograms from 2,910 of the 3,200 patients (90.9%) were evaluated. The median LVEF and LVEDD (37% and 56 mm, respectively) were used as cut-offs for the binary transformation of each parameter. The cumulative death-free survival rates for all patients did not significantly differ based on LVEF or LVEDD quartiles; however, an LVEF greater than the median was associated with a better prognosis in ischemic HF patients (log-rank test; p = 0.039). Among ischemic HF patients, LVEF (dichotomized) was a significant predictor of death in a Cox model after adjusting for a history of HF, age, systolic blood pressure (SBP), serum sodium, sex, diabetes mellitus (DM), chronic obstructive pulmonary disease (COPD), chronic kidney disease (CKD), acute myocardial infarction (AMI), atrial fibrillation (Af) and anemia (hazard ratio (HR) 1.475, 95% confidence interval (CI) 1.099-1.979, p = 0.010). The cumulative readmission-free survival rates significantly differed among ischemic HF patients only when based on LVEDD quartiles (log-rank test; p = 0.001). In multivariate Cox proportional hazards regression analyses, LVEDD (dichotomized) remained a significant variable only among patients with ischemic HF after adjusting for sex, age, AMI, DM, COPD, serum sodium, SBP, blood urea nitrogen (BUN) and anemia (HR 1.401, 95% CI 1.067-1.841, p = 0.015).</AbstractText>Among ischemic AHF patients in the KorHF Registry, LVEF is associated with mortality, whereas LVEDD is only associated with readmission in a binary transformed form.</AbstractText> |
19,802 | Necessity to evaluate PI3K/Akt signalling pathway in proarrhythmia. | The incidence of QT prolongation and torsades de pointes is on the rise due to the use of cardiovascular and non-cardiovascular drugs. Robust efforts have been made and are still ongoing to understand the underlying mechanisms that can enhance or prevent the development of drug-induced proarrhythmia. A caveat in the use of antiarrhythmic drugs is the ability to obtain safe action potential prolongation therapeutic effects, through IKr blockade. This remains as yet completely unachievable, as blockers of the potassium channel have not provided complete safe measures. Because of this, efforts at understanding the mechanisms of proarrhythmia have continued. PI3K/Akt signalling pathway appears to possess some potential advantage in this regard because cardiomyocytes intracellular dialysis with phosphatidylinositol (3,4,5)-trisphosphate (PIP3) normalises ion channel alterations and eliminates proarrhythmic features. However, there is a conundrum. Increased activities of PIP3 signalling can enhance cell proliferation and survival, and reduced activities of PIP3 signalling can lead to proarrhythmia. PI3K inhibitors used in cancer treatment have been found to cause proarrhythmia, and represent a potential avenue for the research and evaluation of potential effectiveness of a battery of antiarrhythmic and cancer drugs that are either currently in use or in development. Despite this knowledge, limited information is available on PI3K/Akt signalling and arrhythmogenesis. This highlights the need to search for new ways to improve testing of antiarrhythmic drugs and increase our understanding in PI3K/Akt signalling and arrhythmogenesis. |
19,803 | Tolerance of Sustained Ventricular Fibrillation During Continuous-Flow Left Ventricular Assist Device Support. | The widespread use of continuous-flow left ventricular assist devices for mechanical circulatory support has shown that long-term hemodynamic support is possible, even when a clinical "pulse" cannot be detected. We present the incidental discovery of ventricular fibrillation in 6 alert, hemodynamically stable patients supported only by a continuous-flow device (HeartMate II, n=5; Jarvik 2000, n=1). Ventricular fibrillation was found in 3 patients during routine outpatient follow-up visits and in 3 awaiting discharge from the hospital after device placement. Diagnosis was confirmed by electrocardiographic and echocardiographic studies. The average duration of mechanical circulatory support before ventricular fibrillation occurred was 221 ± 362 days (range, 5-864 d). All patients were conscious and ambulatory at the time of the arrhythmia. Three patients reported symptoms-primarily fatigue, nausea, and exertional dyspnea-that prompted evaluation. Serum chemistry analysis of blood drawn immediately after diagnosis showed no changes that suggested end-organ dysfunction. Three patients died of unrelated complications an average of 3.9 yr (range, 360-2,270 d) after the event. Two of the remaining 3 patients eventually underwent successful pump explantation, and one is on ongoing support. Our experience shows that it is possible for patients with continuous-flow left ventricular assist devices to remain hemodynamically stable while in ventricular fibrillation. Additional investigation is needed to determine whether defibrillator settings for these patients should be adjusted to limit delivery of shock therapy. |
19,804 | Refractory ventricular fibrillations after surgical repair of atrial septal defects in a patient with CACNA1C gene mutation - case report. | Congenital long QT syndrome (LQTS) can cause ventricular arrhythmic events with syncope and sudden death resulting from malignant torsades de pointes (TdP) followed by ventricular fibrillations (VFs). However, the syndrome is often overlooked prior to the development of arrhythmic events in patients with congenital heart diseases demonstrating right bundle branch block on electrocardiogram (ECG). We present a case of an adult patient with congenital heart disease who developed VFs postoperatively, potentially due to his mutation in a LQTS related gene, which was not identified on preoperative assessment due to incomplete evaluation of his family history.</AbstractText>A 64-year-old man was diagnosed as having multiple atrial septal defects. He presented with no symptoms of heart failure. His preoperative ECG showed complete right bundle branch block (CRBBB) with a corrected QT interval time of 478 ms. He underwent open-heart surgery to close the defects through median sternotomy access. Three hours after the operation, he developed multiple events of TdP and VFs in the intensive care unit. Cardiopulmonary resuscitation and multiple cardioversions were attempted for his repetitive TdP and VFs. He eventually reverted to sinus rhythm, and intravenous beta-blocker was administered to maintain the sinus rhythm. After this event, his family history was reviewed, and it was confirmed that his daughter and grandson had a medical history of arrhythmia. A genetic test confirmed that he had a missense mutation in CACNA1C, p.K1580 T, which is the cause for type 8.</AbstractText>This case highlights the importance of paying attention to other ECG findings in patients with CRBBB, which can mask prolonged QT intervals.</AbstractText> |
19,805 | Impact of long-term glycemic variability on development of atrial fibrillation in type 2 diabetic patients. | It is well known that patients with type 2 diabetes mellitus (T2DM) have a high risk of atrial fibrillation (AF). The current study was designed to determine the relationship between long-term glycemic variability and incidence of new-onset AF in T2DM patients.</AbstractText>Between January 2008 and December 2009, we conducted a retrospective cohort study in patients with T2DM referred to our hospital. In 505 consecutive patients without any medical history of AF at baseline, the relationship between hemoglobin A1c (HbA1c) variability and future AF incidence was evaluated, with adjustments for other possible confounding factors. HbA1c variability was determined by standard deviation (SD) and coefficient of variation (CV).</AbstractText>Over a median of 6.9-year follow-up period, 48 patients (9.5%) developed incident AF. Multiple cox regression revealed that higher HbA1c-SD (HR: 1.726, 95% CI: 1.104-1.830, p=0.001) or HbA1c-CV (HR: 1.241, 95% CI: 1.029-1.497, p=0.024) remained the remarkable predictor of new-onset AF after adjusting for age, body mass index, left ventricular mass index, and left atrium diameter. Receiver operating curve analysis identified thresholds for HbA1c-SD (0.665%, sensitivity 71.4%, specificity 54.9%) and HbA1c-CV (8.970%, sensitivity 73.8%, specificity 47.1%) to detect new-onset AF development.</AbstractText>In patients with T2DM, higher HbA1c variability is significantly associated with future AF development.</AbstractText> |
19,806 | Correlation between plasma brain natriuretic peptide levels and left atrial appendage flow velocity in patients with non-valvular atrial fibrillation and normal left ventricular systolic function. | The left atrial appendage (LAA) flow velocity is an important factor for thrombus formation in patients with non-valvular atrial fibrillation (NV-AF). Recently, the relation of plasma brain natriuretic peptide (BNP) levels and thromboembolism has been reported in patients with NV-AF. The aim of this study was to determine whether the plasma BNP is predictive of lower LAA flow velocity in patients with NV-AF and normal left ventricular (LV) systolic function.</AbstractText>A total of 184 patients with NV-AF (132 men; 65 ± 12 years, LV ejection fraction; 65 ± 10%) underwent transthoracic echocardiography, transesophageal echocardiography (TEE), and measurement of plasma BNP. The LAA flow velocity was obtained by pulsed Doppler TEE. Multivariate logistic regression analysis demonstrated that plasma BNP levels, left atrial volume index (LAVI), LV mass index (LVMI), and the CHADS2</sub> score were independent predictors of lower LAA flow velocity (< 20 cm/s). Plasma BNP levels (r = - 0.58, p < 0.001) were correlated with LAA flow velocity. The area under the curve (AUC) for BNP (AUC 0.803) was larger than that for the CHADS2</sub> score (AUC 0.712), LAVI (AUC 0.664) and LVMI (AUC 0.608) with an optimal BNP cut-off value of 164 pg/ml (sensitivity 75.7%, specificity 71.1%).</AbstractText>This study showed that a higher plasma BNP was associated with a lower LAA flow velocity in patients with NV-AF and normal LV systolic function. The plasma BNP may complement the role of the CHADS2</sub> score in predicting lower LAA flow velocity.</AbstractText> |
19,807 | Clinical implications of serum adiponectin on progression of atrial fibrillation. | The association between circulating adiponectin levels and atrial fibrillation (AF) is uncertain. We, therefore, investigated whether an increased serum adiponectin level is implicated in the long-term recurrence of AF after ablation therapy.</AbstractText>Our study included 100 consecutive patients (88 men; median age, 57.9±10.9 years) who underwent catheter ablation for AF at our hospital between 2011 and 2013. The adiponectin and N-terminal pro-brain natriuretic peptide (NT-proBNP) levels were measured before ablation and compared between those in whom AF recurred and those in whom AF did not recur.</AbstractText>Elevation in adiponectin levels was significantly associated with female sex, non-paroxysmal AF, heart failure, higher NT-proBNP and matrix metallo-proteinase-2 levels, and lower body mass index. After a stepwise adjustment for any potential confounding variables, the adiponectin levels remained significantly associated with female sex (beta=0.2601, P</i>=0.0041), non-paroxysmal AF (beta=0.2708, P</i>=0.0080), and higher NT-proBNP levels (beta=0.2536, P</i>= 0.0138). During the median follow-up period of 26.2 months, AF recurred in 48 of the 100 patients. Stepwise multivariate adjustment showed that an increased log-transformed NT-proBNP (Hazard ratio [HR], 2.18; 95% confidence interval [CI] 1.25-4.00; P</i>=0.0055), longer duration of AF (HR, 1.87; 95%CI 1.01-3.76; P</i>=0.0465), and decreased left ventricular ejection fraction (HR, 0.96; 95%CI 0.93-0.99; P</i>=0.0391) were independent predictors of recurrent AF after catheter ablation, but adiponectin was not.</AbstractText>Our data indicated that adiponectin was partially responsible for progression of AF, but the correlation between adiponectin levels and AF recurrence was not significant.</AbstractText> |
19,808 | Life-threatening arrhythmias leading to syncope in patients with vasospastic angina. | The coronary artery diseases (CAD) that can lead to the occurrence of a syncopal attack include acute coronary syndrome, vasospastic angina, effort angina, and prior myocardial infarction. The possible mechanisms considered to lead to syncope in patients with CAD are pump failure, tachyarrhythmia, bradycardia, and vagal stimulation. Coronary artery spasm, in particular, is occasionally observed in patients with unexplained syncope in Japan. Life-threatening arrhythmias are among the most serious complications of an ischemic attack caused by coronary spasm, and are associated with an increased risk of syncope and/or sudden cardiac death (SCD). Therefore, during the initial evaluation of unexplained syncope, the diagnosis of vasospastic angina (VSA) needs to be made promptly, to avert the risk of SCD as a consequence of syncope triggered by the lethal arrhythmia. The inducibility of polymorphic ventricular tachycardia or ventricular fibrillation, increased QT dispersion, T-wave alternans, and early repolarization during the asymptomatic period are considered risk markers for ventricular arrhythmias during coronary spasm. In view of the conclusions from several studies, implantable cardioverter/defibrillator therapy should be considered in patients who are at high risk for recurrence of syncope due to a fatal ventricular arrhythmia triggered by coronary spasm, despite appropriate medical therapy. |
19,809 | Ventricular Tachycardia Ablation in the Elderly: An International Ventricular Tachycardia Center Collaborative Group Analysis. | Successful ventricular tachycardia (VT) ablation is associated with improved survival in patients with heart failure. However, the safety and efficacy of VT ablation in the elderly, a population with higher competing nonsudden death risk and comorbidities, have not been well defined.</AbstractText>The International Ventricular Tachycardia Center Collaborative Study Group registry of 2061 patients who underwent VT ablation at 12 international centers was analyzed. Kaplan-Meier analysis was used to estimate survival of patients ≥70 years with and without VT recurrence. Of the 2049 patients who met inclusion criteria, 681 (33%) patients were ≥70 years of age (mean age, 75±4 years). Among these, 92% were men, 71% had ischemic VT, and 42% had VT storm at presentation. Mean (±SD) left ventricular ejection fraction was 30±11%. Compared with patients <70 years, patients ≥70 years had higher in-hospital (4.4% versus 2.3%; P</i>=0.01) and 1-year mortality (15% versus 11%; P</i>=0.002) but a similar incidence of VT recurrence at 1 year (26% versus 25%; P</i>=0.74) and time to VT recurrence (280 versus 289 days; P</i>=0.20). Absence of VT recurrence during follow-up was strongly associated with improved survival in patients ≥70 years.</AbstractText>VT ablation in the elderly is feasible and reasonably safe with a modestly higher in-hospital and 1-year mortality, with similar rates of VT recurrence at 1 year compared with younger patients. Successful VT ablation, that is, lack of VT recurrence, is strongly associated with improved survival even in this elderly subgroup.</AbstractText>© 2017 American Heart Association, Inc.</CopyrightInformation> |
19,810 | Idiopathic malignant premature ventricular contractions. | The presence of premature ventricular contractions (PVCs) in patients with structurally normal hearts was once considered a benign phenomenon. However, in susceptible patients, these "benign" or idiopathic PVCs may develop malignant potential and trigger ventricular fibrillation and result in sudden cardiac death. Alternatively, idiopathic PVCs can also induce cardiomyopathy. Clinical recognition of these entities can lead to effective targeted therapy. In the first instance, treatment consists of ablating the PVC source and implanting a defibrillator, whereas in the second scenario, ablating the PVC origin can normalize left ventricular function. |
19,811 | Atrioventricular junction ablation in patients with atrial fibrillation treated with cardiac resynchronization therapy: positive impact on ventricular arrhythmias, implantable cardioverter-defibrillator therapies and hospitalizations. | We sought to determine whether atrioventricular junction ablation (AVJA) in patients with cardiac resynchronization therapy (CRT) implantable cardioverter-defibrillator (ICD) and with permanent atrial fibrillation (AF) has a positive impact on ICD shocks and hospitalizations compared with rate-slowing drugs.</AbstractText>This is a pooled analysis of data from 179 international centres participating in two randomized trials and one prospective observational research. The co-primary endpoints were all-cause ICD shocks and all-cause hospitalizations. Out of 3358 CRT-ICD patients (2720 male, 66.6 years), 2694 (80%) were in sinus rhythm (SR) and 664 (20%) had permanent AF-262 (8%) treated with AVJA (AF + AVJA) and 402 (12%) treated with rate-slowing drugs (AF + Drugs). Median follow-up was 18 months. The mean (95% confidence intervals) annual rate of all-cause ICD shocks per 100 patient years was 8.0 (5.3-11.9) in AF + AVJA, 43.6 (37.7-50.4) in AF + Drugs, and 34.4 (32.5-36.5) in SR patients, resulting in incidence rate ratio (IRR) reductions of 0.18 (0.10-0.32) for AF + AVJA vs. AF + Drugs (P < 0.001) and 0.48 (0.35-0.66) for AF + AVJA vs. SR (P < 0.001). These reductions were driven by significant reductions in both appropriate ICD shocks [IRR 0.23 (0.13-0.40), P < 0.001, vs. AF + Drugs] and inappropriate ICD shocks [IRR 0.09 (0.04-0.21), P < 0.001, vs. AF + Drugs]. Annual rate of all-cause hospitalizations was significantly lower in AF + AVJA vs. AF + Drugs [IRR 0.57 (0.41-0.79), P < 0.001] and SR [IRR 0.85 (073-0.98), P = 0.027].</AbstractText>In AF patients treated with CRT, AVJA results in a lower incidence and burden of all-cause, appropriate and inappropriate ICD shocks, as well as to fewer all-cause and heart failure hospitalizations.</AbstractText>NCT00147290, NCT00617175, NCT01007474.</AbstractText>© 2017 The Authors. European Journal of Heart Failure © 2017 European Society of Cardiology.</CopyrightInformation> |
19,812 | Arterial hypertension and atrial fibrillation: standard and advanced echocardiography from diagnosis to prognostication. | : Structural changes in left and right cardiac chambers that occur in arterial hypertension (AH) may lead to an increased risk of atrial fibrillation. Considering that AH is currently the most common cardiovascular disease in the general population, it represents a major risk factor for atrial fibrillation development. This review explores the complex relationship between atrial fibrillation and AH, starting from its pathophysiological basis. It focuses on the role of echocardiography in the management of hypertensive and atrial fibrillation patients, with emphasis on what should be evaluated about left ventricular remodeling, diastolic and systolic function, left atrial (LA) size and function and right ventricular deformation in patients with AH. |
19,813 | Hypothetical "anatomy" of Brugada phenomenon: "Long QT sine Long QT" syndrome implicating morphologically undefined specific "Brugada's myocells". | The Brugada syndrome (BrS) is associated with increased risk of ventricular arrhythmias and sudden cardiac death. It generates genetically mediated arrhythmias posing a true pathophysiological challenge. In search of the similarities between BrS and long QT syndrome some novel insights are suggested. In patients with BrS the duration of QT interval is usually normal. Some investigators have found prolonged QT interval in the syndrome's natural course or the duration of QT segment have been extended by provocative tests unmasking BrS. Thus, BrS might be characterized as "long QT sine long QT" syndrome. The existence of two functional types of myocites is suspected. Regarding structure and function the majority of ventricular myocardium is probably mostly healthy. The rest of myocardium (preferably the subepicardium of right ventricular outflow tract) due to its genotypic peculiarities demonstrates no negative influence on ventricular performance until early adulthood is reached and/or other unstable preconditions are fulfilled (nocturnal time, fever, specific drugs, etc.). Based on published findings of positive outcomes, following the epicardial ablation of the right ventricular outflow tract region, a new hypothetical concept suggesting the presence of specific, genetically affected "Brugada's myocells" is proposed. These cells as a suitable arrhythmogenic substrate reside intramurally within the subepicardial region of the outflow tract of right ventricle. In the daytime these cells likely are dormant but at rest their nocturnal proarrhythmic behavior is activated occasionally. Presumptions regarding the pathophysiology of BrS might be the focus of further discussion. |
19,814 | Valproic Acid as a Cause of Transient Atrio-Ventricular Conduction Block Episodes. | Herein we share, to our knowledge for the first time, a a case of valproic acid use complicated by symptomatic atrio-ventricular conduction block episodes on Holter monitoring. Symptomatic atrio-ventricular block episodes should be considered as an unusual side effect of valproic acid despite normal blood therapeutic level. Before consideration of pacemaker implantation in such cases, valproic acid usage should be investigated, and dose reduction should be attempted. |
19,815 | Defibrillation Testing During ICD Implantation - Should we or Should we Not? | The implantable cardioverter defibrillator (ICD) is an established therapy for improving mortality for primary and secondary prevention of sudden cardiac death. Whether to perform defibrillation threshold testing (DFT) either intraoperatively or post-operatively remains a controversial issue. The DFT is defined as the minimum energy required at which two shocks can successfully terminate ventricular fibrillation and dates from the era of surgically implanted devices with epicardial patches. Typically, a safety margin of at least 10J is employed for device programming, though some trial data suggest that a margin of 5J could be just as effective. Various methods have been utilized to perform DFT testing, and no particular method has been shown to be superior to another [Figure 1]. Previously, guideline recommendations addressed the indications for ICD implantation but did not comment on DFT testing. Recent consensus statements now provide some guidance as to when it is appropriate to perform or not perform DFT testing in light of new trial data. This review will address some of the risk factors for having a higher DFT, impact of DFT testing on patient outcomes, and some of the risks and contraindications of DFT testing. |
19,816 | Intravenous Sotalol - Reintroducing a Forgotten Agent to the Electrophysiology Therapeutic Arsenal. | Sotalol is a racemic mixture possessing beta-blocker and class III anti arrhythmic properties. Approved by US food and drug administration (FDA) since 2009 based on its bioequivalence with oral sotalol, clinicians are less familiar with the potential uses of the intravenous form despite its re-launch in United States in 2015. Available literature suggests that intravenous sotalol in recommended doses can be safely administered in adult and pediatric population achieving rapid reliable therapeutic plasma concentration and without additional proarrhythmic effects when compared to its oral form as well as other antiarrhythmic medications. Intravenous sotalol may have potential uses as an alternative agent for highly symptomatic atrial fibrillation post cardiac surgery as well as in life threatening ventricular arrhythmias. As with its oral form, judicious use with close attention to QTc and renal function is warranted. Further studies are needed to better understand the safety, efficacy and different dosing regimens of parenteral sotalol in adults and children. |
19,817 | His Bundle Pacing Or Biventricular Pacing For Cardiac Resynchronization Therapy In Heart Failure: Discovering New Methods For An Old Problem. | Heart failure (HF) is one of the biggest epidemics of modern cardiovascular medicine. Cardiac resynchronization therapy (CRT) with biventricular (BiV) pacing has proven to have an integral role in the management of patients with reduced left ventricular (LV) function and left bundle branch blocks (LBBB). However, CRT with BiV pacing is not always feasible and even when it is, the percentage of non-responders remains high. Limitations in LV lead implantation due to anatomical or other constraints; non response to BiV pacing due to lead position or patient related factors and lack of benefit in patients with RBBB and patients with AV block and low normal LV function limit the use of BiV pacing. Permanent His Bundle pacing (HBP) is now a feasible alternative to BiV pacing for CRT therapy. This allows for recruitment of BBB disease and ventricular activation in a more physiological fashion. In this paper we review the physiology of HBP, available data on HBP for CRT and highlight how HBP can be a potential alternative in patients in whom BiV pacing did not provide clinical response or was unsuccessful. |
19,818 | Dilated cardiomyopathy with severe arrhythmias in Emery-Dreifuss muscular dystrophy: from ablation to heart transplantation. | We present 38-years male patient. He has suffered from muscle weakness since 5 years. Arrhythmias appeared at the age of 32. In 37 years he had sick sinus syndrome, transient AV block II degree, paroxysmal atrial fibrillation, atrial flutter, ventricular arrhythmias. At this time, dilated cardiomyopathy was also detected. The evaluation revealed knees and elbows contractures, increased level of creatine kinase. The genetic testing revealed a frame shift deletion c.del619C in the emerin (EMD) gene and c.IVS4-13T> A in the lamin (LMNA) gene, and c.del619C deletion in the heterozygous state in a patient`s mother. Radiofrequency ablation of cavotricuspid isthmus, implantable cardioverter-defibrillator (ICD) implantation were performed. Heart transplantation was performed nine months later, due to severe heart failure and electrical storm. A morphological evaluation revealed sclerosis, atrophy and hypertrophy of cardiomyocytes. He underwent an induction therapy with (basiliximab) methylprednisolone, tacrolimus, mycophenolate after heart transplantation. During 40 months after transplantation, patient`s condition is satisfactory.</AbstractText>heart failure in Emery-Dreifuss muscular dystrophy can progress quickly unless the previously stable condition. The use of correct regimens of immunosuppression therapy provides good long-term results of the heart transplantation.</AbstractText> |
19,819 | Basic Properties And Clinical Applications Of The Intracardiac. | The electric signals detected by intracardiac electrodes provide information on the occurrence and timing of myocardial depolarization, but are not generally helpful to characterize the nature and origin of the sensed event. A novel recording technique referred to as intracardiac ECG (iECG) has overcome this limitation. The iECG is a multipolar signal, which combines the input from both atrial and ventricular electrodes of a dual-chamber pacing system in order to assess the global electric activity of the heart. The tracing resembles a surface ECG lead, featuring P, QRS and T waves. The time-course of the waveform representing ventricular depolarization (iQRS) does correspond to the time-course of the surface QRS with any ventricular activation modality. Morphological variants of the iQRS waveform are specifically associated with each activity pattern, which can therefore be diagnosed by evaluation of the iECG tracing. In the event of tachycardia, SVTs with narrow QRS can be distinguished from other arrhythmia forms based upon the preservation of the same iQRS waveform recorded in sinus rhythm. In ventricular capture surveillance, real pacing failure can be reliably discriminated from fusion beats by the analysis of the area delimited by the iQRS signal. Assessing the iQRS waveform correspondence with a reference template could be a way to check the effectiveness of biventricular pacing, and to discriminate myocardial capture alone from additional His bundle recruitment in para-Hisian stimulation. The iECG is not intended as an alternative to conventional intracavitary sensing, which remains the only tool suitable to drive the sensing function of a pacing device. Nevertheless, this new electric signal can add the benefits of morphological data processing, which might have important implications on the quality of the pacing therapy. |
19,820 | Arrhythmia-Induced Cardiomyopathy: Prevalent, Under-recognized, Reversible. | Arrhythmia-induced cardiomyopathy (AIC) is a clinical condition in which a persistent tachyarrhythmia or frequent ectopy contribute to ventricular dysfunction leading to systolic heart failure. AIC can be partially or completely corrected with adequate treatment of the culprit arrhythmia. Several molecular and cellular alterations by which tachyarrhythmias lead to cardiomyopathy have been identified. AIC can affect children and adults, can be clinically silent in the form of asymptomatic tachycardia with cardiomyopathy, or can present with manifest heart failure. A high index of suspicion for AIC and aggressive treatment of the culprit arrhythmia can result in resolution of heart failure symptoms and improvement in cardiac function. Recurrent arrhythmia, following recovery from the index episode, can hasten the left ventricular dysfunction and result in HF, suggesting persistent adverse remodeling despite recovery of left ventricular function. Several aspects of AIC, such as predisposing factors, early diagnosis, preventive measures to avoid adverse remodeling, and long-term prognosis, remain unclear, and need further research. |
19,821 | Frequent Premature Ventricular Contractions and Cardiomyopathy, Chicken and Egg situation. | Premature ventricular contractions (PVCs) are usually regarded as benign in the absence of structural heart disease. However, frequent PVCs can lead to depressed LV function, called PVC-induced cardiomyopathy and can be reversible after suppression of PVCs. On the other hand, PVCs can be a part of underlying structural heart disease and may be linked to increased risk of sudden death. In this work, we reviewed the current literature on PVC-induced cardiomyopathy based on a case presentation. |
19,822 | Post-Ictal Transient Atrial Fibrillation As A Rare Manifestation Of Grand Mal Seizure. | Atrial fibrillation (AF) most frequently occurs as a consequence of multiple etiologies including valvular disease, coronary artery disease, hyperthyroidism, alcohol ingestion, and pulmonary embolism. However, on rare occasion transient AF may be a result of generalized tonic-clonic seizures (GTCS). A 33-year-old-man presented to the emergency department following GTCS in AF with rapid ventricular response. He had no previous documented history. Diagnostic evaluation including electrolytes, thyroid function, cardiac enzymes, serum and urine drug screen, and two-dimensional echocardiogram were unremarkable. Diltiazem was initiated for rate control with spontaneous conversion to sinus rhythm with no recurrence. AF post-seizure is a rare phenomenon but should be considered in epileptic patients. Anticoagulation must be considered in AF due to the risk of cardioembolic stroke but should be weighed against the potential risk of head injury and subsequent intracranial bleed in patients with grand mal seizures. |
19,823 | Postpacing Interval During Right Ventricular Overdrive Pacing to Discriminate Supraventricular from Ventricular tachycardia. | Failure to differentiate supraventricular from ventricular arrhythmias is the most frequent cause of inappropriate implantable cardioverter-defibrillator (ICD) therapies. We hypothesized that the postpacing interval (PPI) after overdrive right ventricular pacing may differentiate ventricular (VT) from supraventricular tachycardia (SVT) such as sinus tachycardia, atrial flutter and atrial tachycardia. This hypothesis is based on the entrainment maneuver. Reentrant tachycardia circuit for VTs would haveshorter distance to RV apex than SVTs have, and the conduction time between a ventricular pacing site and the tachycardia origin is expected to be shorter in VTs than in SVTs.</AbstractText>220episodes from 38 patients with single chamber ICDs that RV overdrive pacing could not terminate or change the tachycardia cycle length (TCL) were retrospectively reviewed. Episodes were classified as VTs (n=115) and SVTs (n=105). TCLs, PPIs and PPI-TCL were compared between groups.</AbstractText>The cycle length of VTs was shorter than SVTs (320.6±30.3 vs 366.5±40 ms, p=0.001). PPI and PPI-TCL of VTs were shorter than SVTs (504.7±128.3 vs 689.2±121.8 ms, p=0.001, 184±103 vs 322.6±106.6 ms, p=0.001; respectively). ROC curve analysis demonstrated a 525 ms cut-off value for PPI has 89% sensitivity and 57.4% specificity to predict inappropriate ICD therapies due to SVTs (AUC:0.852). Similarly, A PPI-TCL <195 ms favored VT as a diagnosis rather than SVT with a 90% sensitivity, and 51% specificity (AUC:0.838).</AbstractText>Analyzing of PPI during overdrive pacing from RV apex may discriminate supraventricular from ventricular tachycardia. This criterion may have a potential role in implantable devices that use a single ventricular lead.</AbstractText> |
19,824 | California study of Ablation (CAABL):early utilization after index hospitalization for non-valvular atrial fibrillation. | Catheter ablation (ABL) for non-valvular AF (NVAF) is recommended for symptomatic patients refractory to medical therapy and its success is related to the duration of the arrhythmia prior to intervention.Our aim was to assess the early utilization and the factors that prompted ABL in patients hospitalized for new onset NVAF.</AbstractText>Using de-identified administrative discharge records for hospitalizations and emergency department (ED) visits, we determined the patients who had a first-time (since 1991) health record diagnosis of AF between2005 - 2011. We linked ambulatory surgery encounters for ABL based on ICD 9 code occurring within two years of initial hospitalization. After excluding other cardiac arrhythmias, atrio-ventricular nodal ablation or pacemaker/defibrillator placement and cardiac valve disease, bivariate comparisons were made with those who did not undergo ABL.</AbstractText>During the study period,3,440 of 424,592 patients (0.81%) hospitalized for new onset NVAF underwent ABL. Parameters significantly (p<0.001) associated with ABL compared tonon-ABL patientsincluded: principal diagnosis of AF (55% vs 25%), age 35-64 yrs (46.1% vs. 22.4%), male (58.9% vs. 48.2%), private insurance (46.6% vs. 21.1%), Caucasian (81.0% vs.71.6%), lower frequency of ED visit < 6 months before index AF hospitalization (10.7% vs. 15.9%), lower severityofillness at time of AF diagnosis (16.5% vs. 35.6%) anda lower prevalence ofmajor comorbidities (p< 0.001).</AbstractText>Ablation has low utilization for treatment of new onset NVAF within two years of diagnosis. Earlier utilization of ABL may reduce health care burden related to NVAF and requires further evaluation.</AbstractText> |
19,825 | Use of acoustic cardiography immediately following electrical cardioversion to predict relapse of atrial fibrillation. | Predicting atrial fibrillation (AF) recurrence after successful electrical cardioversion (ECV) is difficult. The main aim of this study was to investigate whether acoustic cardiography (AUDICOR® 200) immediately post-ECV might provide indices for AF relapse following cardioversion. Acoustic cardiography parameters included Electromechanical Activation Time (EMAT), Left Ventricular Systolic Time (LVST), QRS duration, heart rate and third heart sound intensity (S3 Strength). We analysed data from 140 patients who underwent successful cardioversion and in whom AUDICOR results and echocardiographic measurements immediately after (baseline) ECV were available. Patients were prospectively followed-up at 4-6 weeks, 3 and 12 months post-ECV, and sinus rhythm maintenance was evaluated using acoustic cardiography and Holter electrocardiography. The effect of each baseline AUDICOR parameter on the hazard of AF relapse was investigated using Cox proportional hazards (PH) models. Fifty patients (35.7%) had AF relapse. Of all the AUDICOR parameters, only S3 Strength exhibited consistent predictive value. Increasing S3 Strength increased the hazard of relapse in a univariable Cox PH model (HR=2.52, p=0.003), and in two multivariable Cox PH model constructions (Model 1 excluded heart rate and Model II excluded EMAT/RR, LVST and LVST/RR) both of which included the parameters as continuous variables (Model I: HR=1.15, p=0.042; Model II: HR=1.14, p=0.045) or the parameters dichotomized according to suggested cut-points (Model I: HR=2.5, p=0.007; Model II: HR=2.09, p=0.031). In conclusion, this study suggests that acoustic cardiography may be a simple inexpensive and quantitative bedside method to assist in prediction of AF recurrence after ECV. |
19,826 | Heart rate as a prognostic marker and therapeutic target in acute and chronic heart failure. | Since increased heart rate (HR) is associated with higher mortality in several cardiac disorders, HR is considered not only a physiological indicator but also a prognostic and biological marker. In heart failure (HF), it represents a therapeutic target in chronic phase. The use or up-titration of beta-blockers, a milestone in HF with reduced left ventricular ejection fraction (LVEF) treatment, is at times limited by patients' hemodynamic profile or intolerance. Ivabradine, a HR-lowering drug inhibiting the f-current in pacemaker cells, has been shown to improve outcome in patients with chronic HF, in sinus rhythm with increased HR beyond beta-blocker therapy. The rationale for this review is to update the role of HR as a prognostic biomarker and a potential therapeutic target in other scenarios than chronic HF; namely, in patients with coexisting atrial fibrillation (AF), in HF with preserved LVEF (HFpEF), in acute HF, and in patients discharged after an episode of acute HF. Preliminary studies and case reports that evaluated the use of ivabradine in the setting of acute HF will be summarized. Recent results of HR reduction in the setting of HFpEF with ivabradine will be presented. Finally, data from large registries and trials that evaluated the prognostic impact of HR in patients with acute HF and sinus rhythm or AF will be reviewed, showing that only patients in sinus rhythm may benefit from HR reduction. |
19,827 | Mitral Valve Adaptation to Isolated Annular Dilation: Insights Into the Mechanism of Atrial Functional Mitral Regurgitation. | This study hypothesized that compensatory mitral leaflet area (MLA) adaptation occurs in patients with persistent atrial fibrillation (AF) without left ventricular (LV) dysfunction but has limitations that augment mitral regurgitation (MR). The study also explored whether asymmetrical annular dilation is matched by relative leaflet enlargement.</AbstractText>Functional MR occurs in patients with AF and isolated annular dilation, but the relationship of MLA adaptation with annular area (AA) is unknown.</AbstractText>Three-dimensional echocardiographic images were acquired from 86 patients with quantified MR: 53 with nonvalvular persistent AF (23 MR+ with moderate or greater MR, 30 MR-) without LV dysfunction or dilation and 33 normal controls. Comprehensive 3-dimensional analysis included total diastolic MLA, adaptation ratios of MLA to annular area and MLA to leaflet closure area, and annular and tenting geometry.</AbstractText>Total MLA was 22% larger in patients with AF than in controls, thus paralleling the increased AA. However, as AA increased, adaptive indices (MLA/AA ratio and ratio of MLA to closure area) plateaued, becoming lowest in MR+ patients (ratio of MLA to closure area = 1.63 ± 0.17 controls, 1.60 ± 0.11 MR-, 1.32 ± 0.10 MR+; p < 0.001). MR increased as the ratio of MLA to closure area decreased (R2</sup> = 0.68; p < 0.001). The posterior-to-anterior MLA ratio remained constant, whereas the posterior-to-anterior mitral annulus perimeter increased (1.21 ± 0.16 controls, 1.32 ± 0.20 MR-, 1.46 ± 0.19 MR+; p < 0.001). Multivariate MR determinants were annular area, total MLA to closure area, and posterior-to-anterior perimeter ratios.</AbstractText>MLA adaptively increases in AF with isolated annular dilation and normal LV function. This compensatory enlargement becomes insufficient with greater annular dilation, and the leaflets fail to match asymmetrical annular remodeling, thereby increasing MR. These findings can potentially help optimize therapeutic options and motivate basic studies of adaptive growth processes.</AbstractText>Copyright © 2019 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
19,828 | Acute myocardial infarction due to simultaneous spasm of 3 coronary arteries that worsened over time. | Coronary artery spasm (CAS) rarely worsens from single-vessel to simultaneous multivessel CAS naturally, and simultaneous multivessel CAS leads to serious conditions such as cardiopulmonary arrest (CPA). A 77-year-old Japanese man who took medications for CAS was transferred to our hospital due to persistent chest pain. On arrival, his vital signs were stable, but his electrocardiogram (ECG) showed ST-segment elevation in leads II, III and aVF. Ventricular fibrillation developed suddenly. Although routine cardiopulmonary resuscitation (CPR) including intravenous administration of epinephrine was performed immediately, he could not be resuscitated. After initiation of percutaneous cardiopulmonary support (PCPS), there was a return of spontaneous circulation. His ECG showed exacerbation of myocardial ischemia with ST-segment elevation in leads I, II, III, aVL, aVF and V3-V6. Emergency coronary angiography revealed severe CAS of the right and left coronary arteries, which was relieved completely by intracoronary administration of nitrates. He was diagnosed with acute myocardial infarction due to simultaneous 3-vessel CAS that progressed over time. About 6h after arrival, he developed hemodynamic instability and died. CAS worsened from single-vessel to simultaneous 3-vessel spasm, and intracoronary administration of nitrates was effective in relieving CAS, which was documented by the ECG and coronary angiogram. Since CAS can progress over time, nitrates must be administered immediately. When CAS leads to CPA, epinephrine may be ineffective in CPR because of its vasoconstrictive effect on coronary arteries; therefore, PCPS should be initiated, and intracoronary nitrates should be administered. |
19,829 | Real-world incidence of efficacy and safety outcomes in patients on direct oral anticoagulants with left ventricular systolic dysfunction at a tertiary referral center. | Patients with heart failure (HF) have increased risk for thromboembolic events. Real-world incidences of efficacy and safety outcomes of direct oral anticoagulants (DOACs) in patients with left ventricular systolic dysfunction (LVSD) are of growing clinical interest.</AbstractText>Real-world efficacy and safety outcomes of DOACs in patients with LVSD will be similar to those of LVSD or HF subgroups in the RE-LY, ROCKET-AF, and ARISTOTLE trials.</AbstractText>We performed a retrospective review of adult patients with LVSD (left ventricular ejection fraction ≤40%) on DOAC therapy between 2010 and 2016. Incidences of safety and efficacy outcomes of anticoagulation with DOACs were extracted from primary and secondary hospital discharge diagnoses.</AbstractText>DOACs were prescribed to 287 patients with LVSD over a mean follow-up of 313.3 ± 52.3 days. Many patients had moderate and severe chronic kidney disease (28.9% and 10.1%, respectively) and indications for anticoagulation therapy other than atrial fibrillation (19.9%). For efficacy outcomes, the calculated incidence rates of ischemic stroke and systemic embolism were 1.2 (95% confidence interval [CI]: 0.25-3.56) and 0.81 (95% CI: 0.10-2.94) events per 100 person-years, respectively. For the safety outcomes, incidence rates of GI bleeding and intracranial hemorrhage were 2.4 (95% CI: 0.8-5.3) and 0.41 (95% CI: 0.1-2.2) events per 100 patient-years, respectively.</AbstractText>Our findings are largely compatible with the results of LVSD or HF subgroups in RE-LY, ROCKET-AF, and ARISTOTLE trials and add to increasing confidence that DOACs can be safely used for stroke and systemic embolism prevention in patients with LVSD.</AbstractText>© 2017 Wiley Periodicals, Inc.</CopyrightInformation> |
19,830 | Endocardial Activation Drives Activation Patterns During Long-Duration Ventricular Fibrillation and Defibrillation. | Understanding the mechanisms that drive ventricular fibrillation is essential for developing improved defibrillation techniques to terminate ventricular fibrillation (VF). Distinct organization patterns of chaotic, regular, and synchronized activity were previously demonstrated in VF that persisted over 1 to 2 minutes (long-duration VF [LDVF]). We hypothesized that activity on the endocardium may be driving these activation patterns in LDVF and that unsuccessful defibrillation shocks may alter activation patterns.</AbstractText>The study was performed using a 64-electrode basket catheter on the left ventricle endocardium and 54 6-electrode plunge needles inserted into the left ventricles of 6 dogs. VF was induced electrically, and after short-duration VF (10 seconds) and LDVF (7 minutes), shocks of increasing strengths were delivered every 10 seconds until VF was terminated. Endocardial activation patterns were classified as chaotic (varying cycle lengths and nonsynchronous activations), regular (highly repeatable cycle lengths), and synchronized (activation that spreads rapidly over the endocardium with diastolic periods between activations).</AbstractText>The results showed that the chaotic pattern was predominant in early VF, but the regular pattern emerges as VF progressed. The synchronized pattern only emerged occasionally during late VF. Failed defibrillation shocks changed chaotic and regular activation patterns to synchronized patterns in LDVF but not in short-duration VF. The regular and synchronized patterns of activation were driven by rapid activations on the endocardial surface that blocked and broke up transmurally, leading to an endocardial to epicardial activation rate gradient as LDVF progressed.</AbstractText>© 2017 American Heart Association, Inc.</CopyrightInformation> |
19,831 | Relative timing of near-field and far-field electrograms can determine the tachyarrhythmia site of origin. | Despite improving algorithms, inappropriate shocks for supraventricular tachycardia (SVT) still occur in a significant number of patients with implantable cardioverter-defibrillators (ICDs). This makes the discovery of novel discriminators that use existing ICD hardware an attractive proposition.</AbstractText>We hypothesized that the delay of activation onset from the device-detected, far-field electrogram (EGM) to the near-field, bipole EGM would allow the differentiation of ventricular tachycardias (VTs) from SVTs.</AbstractText>Proof of principle was demonstrated by rapid pacing in the right atrium, right ventricle, and left ventricle in healthy patients undergoing atrial fibrillation ablation procedures (n = 17). Using real-life ICD recordings, the equivalent measurements were made in a derivation cohort (n = 26) and cutoff predictive values obtained. Finally, the selected values were validated in a separate group of recordings (n = 82).</AbstractText>In healthy patients, significant differences in the far-field to near-field EGM activation onsets were observed between right atrial (14.7 ± 2.7 ms), right ventricular (36.3 ± 8 ms), and left ventricular (57.8 ± 10.3 ms; P < .001) pacing. In the derivation ICD cohort, the median far-field to near-field onset delay was significantly shorter in SVT (24.5 ms; interquartile range, 15.3-47.5 ms) than in VT (118.5 ms; interquartile range, 102.5-131.5 ms) (P < .001). Using a cutoff of 100 ms in the validation cohort, SVT was successfully discriminated from VT with a sensitivity and specificity of 88% and a negative predictive value of 94.2%.</AbstractText>The delay between far-field and near-field EGMs offers a potential new discrimination tool to reduce inappropriate ICD therapies and aid interpretation of single-lead device tracings.</AbstractText>Copyright © 2017 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
19,832 | Catheter ablation versus rate control in patients with atrial fibrillation and heart failure: A multicenter study. | Many trials have shown improvements in left ventricular function, exercise capacity, and quality of life after catheter ablation (CA) of atrial fibrillation (AF) in patients with heart failure (HF). We sought to evaluate the impact of CA on hard outcomes in a retrospective cohort study. AF patients with symptomatic HF from 3 hospitals were included. Our primary endpoint was major adverse cardiac events (MACEs), a composite of all-cause mortality, stroke, and unplanned hospitalization. In total, 90 patients underwent CA and 304 ones received rate control (RaC) were included. After a mean follow-up of 13.5 ± 5.3 months, 82.2% of patients in CA group got freedom from AF; all patients in RaC group remained in AF. CA group had a significant decreased risk of MACEs compared with RaC group (13.3% vs 29.3%, hazard ratio [HR] 0.51, 95% confidence interval [CI]: 0.32-0.82, P = .005). After propensity score matched for confounding factors, difference in MACEs remained significant between groups (13.3% vs 25.6%, HR 0.50, 95% CI: 0.26-0.98, P = .044). Multivariate regression analysis also indicated that CA was significantly associated with a lower risk of MACEs in overall cohort (HR 0.486, 95% CI: 0.253-0.933, P = .030) and in propensity-matched cohort (HR 0.482, 95% CI: 0.235-0.985, P = .045). Besides, age and NYHA class were associated with an increased risk of MACEs. In conclusion, the present study demonstrated that CA for AF in HF patients could reduce the risk of MACEs in a mid-term follow-up. Thus, CA may be a reasonable option for this population. |
19,833 | Catheter Ablation of Focal Atrial Tachycardia Using Remote Magnetic Navigation. | The outcomes of catheter ablation in focal atrial tachycardia (AT) using remote magnetic navigation (RMN) are still controversial. The objectives of this study were to assess the acute and long-term outcomes of catheter ablation in focal AT using RMN.</AbstractText>A total of 53 patients with focal AT who underwent catheter ablation using RMN were included. Thirty-six patients had structural heart disease, including previous atrial fibrillation ablation and heart surgery (abnormal group), and the remaining 17 patients had no structural heart disease (normal group).</AbstractText>In 53 patients, a total of 56 atrial foci were found. Acute success of the primary ablation was obtained in 52 patients (98%). Mean procedure duration was 109 ± 35 min, ablation duration was 401 sec (interquartile range [IQR], 332 sec), and fluoroscopy time was 5.0 min (IQR, 3.0 min). After a mean follow-up of 31 ± 18 months, 47 patients (89%) were free from focal AT. No major complications were observed. In the abnormal group, age and target atrium volume were higher and the left ventricular ejection fraction was lower when compared to the normal group. However, there were no significant differences in procedure duration (normal group 106 ± 31 min vs abnormal group 111 ± 37 min); ablation duration (normal group 457 sec [IQR, 412 sec] vs abnormal group 378 sec [IQR, 217 sec]); fluoroscopy time (normal group 4.2 min [IQR, 3.0 min] vs abnormal group 5.4 min [IQR, 3.3 min]); acute success rate (normal group 100% vs abnormal group 97%); and long-term success rate (normal group 88% vs abnormal group 89%) between the two groups (P>.05).</AbstractText>Our study has demonstrated that catheter ablation of focal AT using RMN is safe and effective, with low fluoroscopy exposure.</AbstractText> |
19,834 | Pulmonary Vasodilator Therapy in Shock-associated Cardiac Arrest. | Many in-hospital cardiac arrests are precipitated by hypotension, often associated with systemic inflammation. These patients are less likely to be successfully resuscitated, and novel approaches to their treatment are needed.</AbstractText>To determine if the addition of inhaled nitric oxide (iNO) to hemodynamic-directed cardiopulmonary resuscitation (HD-CPR) would improve short-term survival from cardiac arrest associated with shock and systemic inflammation.</AbstractText>In 3-month-old swine (n = 21), LPS was intravenously infused, inducing systemic hypotension. Ventricular fibrillation was induced, and animals were randomized to blinded treatment with either: 1) HD-CPR with iNO, or 2) HD-CPR without iNO. During HD-CPR, chest compression depth was titrated to peak aortic compression pressure of 100 mm Hg, and vasopressor administration was titrated to coronary perfusion pressure greater than or equal to 20 mm Hg. Defibrillation attempts began after 10 minutes of resuscitation. The primary outcome was 45-minute survival.</AbstractText>The iNO group had higher rates of 45-minute survival (10 of 10 vs. 3 of 11; P = 0.001). During cardiopulmonary resuscitation, the iNO group had lower pulmonary artery relaxation pressure (mean ± SEM, 10.9 ± 2.4 vs. 18.4 ± 2.4 mm Hg; P = 0.03), higher coronary perfusion pressure (21.1 ± 1.5 vs. 16.9 ± 1.0 mm Hg; P = 0.005), and higher aortic relaxation pressure (36.6 ± 1.6 vs. 30.4 ± 1.1 mm Hg; P < 0.001) despite shallower chest compressions (5.88 ± 0.25 vs. 6.46 ± 0.40 cm; P = 0.02) and fewer vasopressor doses in the first 10 minutes (median, 4 [interquartile range, 3-4] vs. 5 [interquartile range, 5-6], P = 0.03).</AbstractText>The addition of iNO to HD-CPR in LPS-induced shock-associated cardiac arrest improved short-term survival and intraarrest hemodynamics.</AbstractText> |
19,835 | The athlete's heart is a proarrhythmic heart, and what that means for clinical decision making. | Recurring questions when dealing with arrhythmias in athletes are about the cause of the arrhythmia and, more importantly, about the eligibility of the athlete to continue sports activities. In essence, the relation between sports and arrhythmias can be understood along three lines: sports as arrhythmia trigger on top of an underlying problem, sports as arrhythmic substrate promotor, or sports as substrate inducer. Often, there is no sharp divider line between these entities. The athlete's heart, a heart that adapts so magically to cope with the demands of exercise, harbours many structural and functional changes that by themselves predispose to arrhythmia development, at the atrial, nodal and ventricular levels. In essence, the athlete's heart is a proarrhythmic heart. This review describes the changes in the athlete's heart that are related to arrhythmic expression and focuses on what this concept means for clinical decision making. The concept of the athlete's heart as a proarrhythmic heart creates a framework for evaluation and counselling of athletes, yet also highlights the difficulty in predicting the magnitude of associated risk. The management uncertainties are discussed for specific conditions like extreme bradycardic remodelling, atrioventricular nodal reentrant tachycardia, atrial fibrillation and flutter, and ventricular arrhythmias. |
19,836 | Shock Reduction With Antitachycardia Pacing Before and During Charging for Fast Ventricular Tachycardias in Patients With Implantable Defibrillators. | Fast ventricular tachycardias in the ventricular fibrillation zone in patients with an implantable cardioverter-defibrillator are susceptible to antitachycardia pacing (ATP) termination. Some manufacturers allow programming 2 ATP bursts: before charging (BC) and during (DC) charging. The aim of this study was to describe the safety and effectiveness of ATP BC and DC for fast ventricular tachycardias in the ventricular fibrillation zone in patients with an implantable cardioverter-defibrillator in daily clinical practice.</AbstractText>Data proceeded from the multicenter UMBRELLA trial, including implantable cardioverter-defibrillator patients followed up by the CareLink monitoring system. Fast ventricular tachycardias in the ventricular fibrillation zone until a cycle length of 200ms with ATP BC and/or ATP DC were included.</AbstractText>We reviewed 542 episodes in 240 patients. Two ATP bursts (BC/DC) were programmed in 291 episodes (53.7%, 87 patients), while 251 episodes (46.3%, 153 patients) had 1 ATP burst only DC. The number of episodes terminated by 1 ATP DC was 139, representing 55.4% effectiveness (generalized estimating equation-adjusted 60.4%). There were 256 episodes terminated by 1 or 2 ATP (BC/DC), representing 88% effectiveness (generalized estimating equation-adjusted 79.3%); the OR for ATP effectiveness BC/DC vs DC was 2.5, 95%CI, 1.5-4.1; P <.001. Shocked episodes were 112 (45%) for ATP DC vs 35 (12%) for ATP BC/DC, representing an absolute reduction of 73%. The mean shocked episode duration was 16seconds for ATP DC vs 19seconds for ATP BC/DC (P=.07).</AbstractText>The ATP DC in the ventricular fibrillation zone for fast ventricular tachycardia is moderately effective. Adding an ATP burst BC increases the overall effectiveness, reduces the need for shocks, and does not prolong episode duration.</AbstractText>Copyright © 2017 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.</CopyrightInformation> |
19,837 | Hydroquinidine Prevents Life-Threatening Arrhythmic Events in Patients With Short QT Syndrome. | Short QT syndrome (SQTS) is a rare and life-threatening arrhythmogenic syndrome characterized by abbreviated repolarization. Hydroquinidine (HQ) prolongs the QT interval in SQTS patients, although whether it reduces cardiac events is currently unknown.</AbstractText>This study investigated whether long-term treatment with HQ reduces the occurrence of life-threatening arrhythmic events (LAE) (cardiac arrest or sudden cardiac death) in SQTS patients.</AbstractText>In this cohort study on consecutive SQTS patients, 2 analyses were performed: 1) a matched-period analysis for the occurrence of LAE in 17 SQTS patients who received long-term HQ; and 2) a comparison of the annual incidence of LAE off- and on-HQ in 16 SQTS patients who survived a cardiac arrest.</AbstractText>A total of 17 patients (82% male, age 29 ± 3 years, QTc before treatment 331 ± 3 ms) received HQ therapy (584 ± 53 mg/day). Therapy was stopped in 2 cases (12%) due to gastrointestinal intolerance, and 15 patients continued treatment for 6 ± 1 year. QTc prolongation was observed in all patients (by 60 ± 6 ms; p < 0.001). We compared the occurrence of LAE during 6 ± 1 years before and after HQ, observing that patients on HQ experienced a reduction in both the rate of LAE from 40% to 0% (p = 0.03) and the number of LAE per patient from 0.73 ± 0.3 to 0 (p = 0.026). Furthermore, the annual rate of LAE in the 16 patients with a previous cardiac arrest dropped from 12% before HQ to 0 on therapy (p = 0.028).</AbstractText>We demonstrated for the first time that treatment with HQ was associated with a lower incidence of LAE in SQTS patients. These data point to the importance that quinidine, that in several countries has been removed from the market, remains available worldwide for patients with SQTS. In the present study, therapy with HQ has been proven to be safe, with a relatively low rate of side effects.</AbstractText>Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
19,838 | Induction of Inflammation In Vivo by Electrocardiogram Sensor Operation Using Wireless Power Transmission. | Prolonged monitoring by cardiac electrocardiogram (ECG) sensors is useful for patients with emergency heart conditions. However, implant monitoring systems are limited by lack of tissue biocompatibility. Here, we developed an implantable ECG sensor for real-time monitoring of ventricular fibrillation and evaluated its biocompatibility using an animal model. The implantable sensor comprised transplant sensors with two electrodes, a wireless power transmission system, and a monitoring system. The sensor was inserted into the subcutaneous tissue of the abdominal area and operated for 1 h/day for 5 days using a wireless power system. Importantly, the sensor was encapsulated by subcutaneous tissue and induced angiogenesis, inflammation, and phagocytosis. In addition, we observed that the levels of inflammation-related markers increased with wireless-powered transmission via the ECG sensor; in particular, levels of the Th-1 cytokine interleukin-12 were significantly increased. The results showed that induced tissue damage was associated with the use of wireless-powered sensors. We also investigated research strategies for the prevention of adverse effects caused by lack of tissue biocompatibility of a wireless-powered ECG monitoring system and provided information on the clinical applications of inflammatory reactions in implant treatment using the wireless-powered transmission system. |
19,839 | Spatiotemporal Progression of Early Human Ventricular Fibrillation. | The objective of this study was to evaluate the spatio-temporal organization and progression of human ventricular fibrillation (VF) in the left (LV) and right (RV) ventricles.</AbstractText>Studies suggest that localized sources contribute to VF maintenance, but the evolution of VF episodes has not been quantified.</AbstractText>Synchrony between electrograms recorded from 25 patients with induced VF is computed and used to define the Asynchronous Index (ASI), indicating regions which are out-of-step with surrounding tissue. Computer simulations show that ASI can identify the location of VF-maintaining sources, where larger values of ASImax</sub> correlate with more stable sources.</AbstractText>Automated synchrony analysis shows elevated values of ASI in a majority of self-terminating episodes (LV: 8/9, RV: 7/8) and sustained episodes (LV: 11/11, RV: 12/12). The locations of ASImax</sub> in sustained episodes co-localize with rotor cores when rotational activity is simultaneously present in phase maps (LV: 8/8, RV: 5/7, p<.05). The distribution of ASImax</sub> differentiates self-terminating from sustained episodes (mean ASImax</sub> = 0.60±0.14 and 0.70±0.16, respectively; p=0.01). Across sustained episodes the LV exhibits an increase in ASImax</sub> with time.</AbstractText>Quantitative analysis identifies localized asynchronous regions that correlate with sources in VF, with sustained episodes evolving to exhibit more stable activation in the LV. This successive increase in stability indicates a stabilizing agent may be responsible for perpetuating fibrillation in a "migrate-and-capture" mechanism in the LV.</AbstractText> |
19,840 | Gene-Based Risk Stratification for Cardiac Disorders in <i>LMNA</i> Mutation Carriers. | Mutations in LMNA</i> (lamin A/C</i>), which encodes lamin A and C, typically cause age-dependent cardiac phenotypes, including dilated cardiomyopathy, cardiac conduction disturbance, atrial fibrillation, and malignant ventricular arrhythmias. Although the type of LMNA</i> mutations have been reported to be associated with susceptibility to malignant ventricular arrhythmias, the gene-based risk stratification for cardiac complications remains unexplored.</AbstractText>The multicenter cohort included 77 LMNA</i> mutation carriers from 45 families; cardiac disorders were retrospectively analyzed. The mean age of patients when they underwent genetic testing was 45±17, and they were followed for a median 49 months. Of the 77 carriers, 71 (92%) were phenotypically affected and showed cardiac conduction disturbance (81%), low left ventricular ejection fraction (<50%; 45%), atrial arrhythmias (58%), and malignant ventricular arrhythmias (26%). During the follow-up period, 9 (12%) died, either from end-stage heart failure (n=7) or suddenly (n=2). Genetic analysis showed truncation mutations in 58 patients from 31 families and missense mutations in 19 patients from 14 families. The onset of cardiac disorders indicated that subjects with truncation mutations had an earlier occurrence of cardiac conduction disturbance and low left ventricular ejection fraction, than those with missense mutations. In addition, the truncation mutation was found to be a risk factor for the early onset of cardiac conduction disturbance and the occurrence of atrial arrhythmias and low left ventricular ejection fraction, as estimated using multivariable analyses.</AbstractText>The truncation mutations were associated with manifestation of cardiac phenotypes in LMNA</i>-related cardiomyopathy, suggesting that genetic analysis might be useful for diagnosis and risk stratification.</AbstractText>© 2017 American Heart Association, Inc.</CopyrightInformation> |
19,841 | EvaLuation Using Cardiac Insertable Devices And TelephonE in Hypertrophic Cardiomyopathy (ELUCIDATE HCM)-rationale and design: a prospective observational study on incidence of arrhythmias in Sweden. | Hypertrophic cardiomyopathy (HCM) is a heterogeneous disease associated with sudden cardiac death (SCD) mainly due to ventricular tachycardia (VT) or fibrillation even though life-threatening bradycardia occurs. Risk stratification takes several variables into consideration including non-sustained VT (NSVT). An implantable cardioverter defibrillator effectively prevents SCD.Atrial fibrillation (AF) is common among patients with HCM and warrants anticoagulation even without conventional risk factors according to European guidelines. Routinely, the evaluation of arrhythmias using a 48-hour ambulatory external monitor takes place every 6-24 months if patients do not report palpitations. The remaining time the potential burden arrhythmia is unknown. Therefore, the aim of the present study is to assess NSVT and AF incidence during 18 months by an insertable cardiac monitor (ICM).</AbstractText>Adult patients, aged 18-65 years, with a validated diagnosis of HCM are eligible for the study. The study sample is planned to include 30 patients. A Confirm Rx is implanted at the level of the fourth rib on the left side subcutaneously after local anaesthesia. The application for monitoring is installed in the patients' smartphone and symptoms registered by the patient activation and VT detection programmed as 160 bpm during ≥8 intervals. An AF episode is recorded based on ≥2 min duration. Bradycardia is recorded at ≤40 bpm or pause ≥3.0 s. The patients are followed during 18 months before explant.</AbstractText>The study was approved by The Regional Ethical Committee in Umeå (protocol number 2017/13-31). The study protocol, including variables and prespecified research questions, the study was registered at Clinical Trial Registration NCT03259113. Each patient is informed about the study in both oral and written form by a physician and included after written consent.</AbstractText>© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.</CopyrightInformation> |
19,842 | Significance of Inducible Nonsustained Ventricular Tachycardias After Catheter Ablation for Ventricular Tachycardia in Ischemic Cardiomyopathy. | Noninducibility of sustained monomorphic ventricular tachycardia (SMVT) postablation does not insure absence of later recurrence in patients with ischemic cardiomyopathy. This study aims to determine the relation between inducible nonsustained VT postablation and VT recurrences.</AbstractText>One hundred sixty-five consecutive patients (156 male; age 68±9 years) underwent ablation for SMVT because of ischemic cardiomyopathy; 44 patients who did not have induction testing or in whom only ventricular fibrillation was induced after ablation were excluded. In 38 patients (23%), SMVT was inducible (group C). Of the 83 patients without inducible SMVT after ablation, nonsustained VT defined as ≥5 beats lasting for <30 s, was induced in 34 patients (group B, 21%), whereas the remaining 49 patients had no VT induced by the induction test (group A, 30%). Over a median follow-up of 18.7 months, freedom from recurrent VT at 24 months was 60% in group A, 45% in group B (P</i>=0.017 versus group A), and 38% in group C (P</i>=0.005 versus group A). In patients without inducible SMVT, inducible nonsustained VT and left ventricular ejection fraction was independently associated with VT recurrence (hazard ratio, 3.66 and 1.07; 95% CI, 1.3-11.1 and 1.01-1.14).</AbstractText>Inducible nonsustained VT postablation suggests the continued presence of functional arrhythmia substrate. Further trials are needed to assess whether additional ablation would improve outcome in this group.</AbstractText>© 2017 American Heart Association, Inc.</CopyrightInformation> |
19,843 | Exercise-related severe cardiac events. | Physical activity has benefits on health. However, there is a small risk of effort-related adverse events. The aim of this study is to describe exercise-related severe cardiovascular events and to relate them with the type of sport performed. We performed a ten-year retrospective study in eight Spanish cardiac intensive care units. Adverse cardiac events were defined as acute myocardial infarction, cardiac arrest or syncope related to physical activity. From 117 patients included, 109 were male (93.2%), and mean age was 51.6 ± 12.3 years; 56 presented acute myocardial infarction without cardiac arrest (47.9%), 55 sudden cardiac death (47.0%) and six syncope (5.1%). The sports with higher number of events were cycling (33%-28.2%), marathon or similar running competitions (19%-16.2%), gymnastics (18%-15.3%) and soccer (17%-14.5%). Myocardial infarction was observed more frequently in cyclists compared to other sports (69.7% vs 39.3%, P = .001). The most common cause of sudden cardiac death was myocardial infarction in those >35 years (23%-63.9%) and idiopathic ventricular fibrillation in younger patients (5%-62.5%). Significant coronary artery disease was present in 85 (79.4%). Only one patient with cardiac arrest presented with a non-shockable rhythm (asystole). Eleven patients (9.4%) died during hospitalization; in all cases, they had presented cardiac arrest. All discharged patients were alive at the end of follow-up. Exercise-related severe cardiac events are mainly seen in men. Coronary heart disease is very frequent; about half present acute myocardial infarction and the other half cardiac arrest. In our cohort, prognosis was good in patients without cardiac arrest. |
19,844 | Long-Term Survival of Discharged Patients Admitted to Intensive Coronary Care Unit after Out-of-Hospital Cardiac Arrest. | Survival of patients who were discharged from the hospital following out-of-hospital cardiac arrest (OHCA) has not been well defined.</AbstractText>To verify predictor variables for prognosis of patients following OHCA who survived hospitalization.</AbstractText>We retrospectively reviewed clinical, demographic, and outcome data of consecutive patients who were hospitalized from January 1, 2009, through December 31, 2014, into the intensive coronary care unit (ICCU) after aborted OHCA and discharged alive. The patients were followed until December 31, 2015.</AbstractText>Of the 180 patients who were admitted into ICCU after OHCA, 64 were discharged alive (59.3%): 55 were male (85.9%), 14 died 16.5 ± 18 months after their discharge. During 1 year follow-up, nine patients (14.1%) died after a median period of 5.5 months and 55 patients (85.9 %) survived. Diabetes mellitus and chronic renal failure (CRF) were more frequent in patients who died within 1 year after their hospital discharge than those who survived. Ventricular fibrillation, such as initial arrhythmia, and opening of occluded infarct related artery were more frequent in survivors.</AbstractText>Most of the patients who were discharged after OHCA were alive at the 1 year follow-up. The risk of death of cardiac arrest survivors is greatest during the first year after discharge. CRF remains a poor long-term prognostic factor beyond the patients' discharge. Ventricular fibrillation, as initial arrhythmia, and opening of occluded infarct related artery have a positive impact on long-term survival.</AbstractText> |
19,845 | Left atrial enlargement and clinical considerations in patients with or without a residual interatrial shunt after closure of the left atrial appendage with the WATCHMAN™-device. | Interventional closure of the left atrial appendage (LAA) in patients with non-valvular atrial fibrillation, high thromboembolic and bleeding risk or bleeding history is an alternative therapeutic strategy to oral anticoagulation. It is not known if the exclusion of the LAA from the blood circulation affects the left atrial volume (LAV) and consequently its prognostic value or the circulatory performance of the heart in humans.</AbstractText>We aimed to prospectively assess potential changes in baseline LAV, left ventricular ejection fraction (LVEF), NT-proBNP-level and the covered distance in the 6-min walk-test 6 weeks and 6 months after LAA closure with the WATCHMAN™ device. We used serial 3-dimensional transthoracic and transesophageal echocardiography to assess LAV, residual interatrial shunt and device performance in 58 consecutive patients with successful LAA closure.</AbstractText>Accurate 3D-echocardiographic data for LAV measurements were evaluable for 51 (91%) patients. Maximum LAV (LAVmax) at baseline was 102.8 ± 30.8 ml and increased significantly to 107.7 ± 32.8 ml after 6 weeks (p < 0.01) and 113.5 ± 34.2 ml after 6 months (p < 0.01). Minimal LAV (LAVmin) increased from 76.9 ± 29.5 ml at baseline to 81.8 ± 30.2 ml after 45 days (p < 0.01) and 82.1 ± 33.3 ml after 6 months (p < 0.01). Similarly, their indexes to BSA (LAVImax and LAVImin) increased significantly, as well. Patients without a residual left-to-right interatrial shunt showed a significantly higher increase in LAVmax or LAVmin. Baseline LVEF, NT-proBNP-level or the distance covered at the 6-min walk test did not significantly change 6 weeks or 6 months after LAA closure.</AbstractText>LAVmax and LAVmin increase significantly after interventional LAA closure. LA enlargement does not correlate with clinical progression of heart failure. Persistent left-to-right interatrial shunt counteracts the LA enlargement. A reduced LA compliance after exclusion of the LAA from the blood circulation with consecutive increase in LA pressure may be a potential cause of LA enlargement and warrants further investigation.</AbstractText>German Clinical Trials Register ID: DRKS00010768 ; Registration Date 07.07.2016.</AbstractText> |
19,846 | Arrhythmogenic right ventricular cardiomyopathy and left atrial tachycardia: a case report. | Little is known about atrial arrhythmias in arrhythmogenic right ventricular cardiomyopathy (ARVC). A 46-year-old man with definite ARVC presented with palpitations and exertional dyspnoea. Electrocardiogram showed a supraventricular tachycardia. Despite no prior cardiac surgery or atrial fibrillation ablation, electrophysiological study revealed a left atrial (LA) re-entrant circuit characterized by a slow fractionated potential bounded by two areas of double potentials giving a figure-of-eight pattern on activation map. Located on the LA roof within a zone of low bipolar voltages, this unusual substrate can be associated with a primitive atrial myopathy in ARVC. |
19,847 | Isolated tricuspid regurgitation: outcomes and therapeutic interventions. | Isolated tricuspid regurgitation (TR) can be caused by primary valvular abnormalities such as flail leaflet or secondary annular dilation as is seen in atrial fibrillation, pulmonary hypertension and left heart disease. There is an increasing recognition of a subgroup of patients with isolated TR in the absence of other associated cardiac abnormalities. Left untreated isolated TR significantly worsens survival. Stand-alone surgery for isolated TR is rarely performed due to an average operative mortality of 8%-10% and a paucity of data demonstrating improved survival. When surgery is performed, valve repair may be preferred over replacement; however, there is a risk of significant recurrent regurgitation after repair. Existing society guidelines do not fully address the management of isolated TR. We propose that patients at low operative risk with symptomatic severe isolated TR and no reversible cause undergo surgery prior to the onset of right ventricular dysfunction and end-organ damage. For patients at increased surgical risk novel percutaneous interventions may offer an alternative treatment but further research is needed. Significant knowledge gaps remain and future research is needed to define operative outcomes and provide comparative data for medical and surgical therapy. |
19,848 | Postcardiotomy refractory ventricular fibrillation: rescue using veno-arterial extracorporeal membrane oxygenation. | We present a case of 7-hour ventricular fibrillation with successful use of veno-arterial extracorporeal membrane oxygenation as a bridge to recovery in a 30-year-old patient with grown-up congenital heart disease who underwent pulmonary valve replacement. |
19,849 | Treatment of ineffective endocardial defibrillation with subcutaneous array: a case report. | Defibrillation threshold (DFT) testing is an important part of ICD implantation. After placement of the ICD generator, a DFT test is performed to evaluate the integrity of the ICD system and to confirm a successful defibrillation safety margin. More than 6% of ICDs implanted are not within the DFT safety margin. Presently described is the case of a patient with a high DFT and some of the methods that can be used to manage this circumstance, including the use of a subcutaneous array. |
19,850 | Public access defibrillation in Hong Kong in 2017. | The concept of public access defibrillation was proposed more than 20 years ago. Since then, various programmes have been implemented in many major cities although not all have been successful. Fourteen years ago, the question of whether Hong Kong needed public access defibrillation was raised. This article aimed to answer this question based on the best available evidence. Over the years, the clinical effectiveness of public access defibrillation in out-of-hospital cardiac arrest has been proven. Nonetheless various studies have indicated that among others, cost-effectiveness, knowledge and attitudes of the public, and incidence of ventricular fibrillation are important factors that will affect the likelihood of success of such programmes. In Hong Kong, because of the long interval between recognition of arrest and first defibrillation, public access defibrillation is probably needed. To ensure the success of such a programme, careful planning in addition to the installation of more automated external defibrillators are essential. |
19,851 | Newly developed atrial fibrillation progresses to a more severe INTERMACS score in a patient with advanced heart failure due to dilated cardiomyopathy. | We have presented a case of advanced HF, in which newly developed AF hastened the timing of the implantation of mechanical support. Newly developed AF in advanced HF may be intractable by medical therapies and could be a key event that determines the timing of mechanical support. |
19,852 | Evaluation of QT dispersion and T-peak to T-end interval in patients with early-stage sarcoidosis. | Sarcoidosis increases inhomogeneity in ventricular repolarization due to the presence of sarcoid granuloma, which significantly correlates with ventricular fibrillation. Various studies have suggested that the interval from the peak to the end of the electrocardiographic T wave (T-peak to T-end [Tpe] interval) may correspond to the transmural dispersion of repolarization and that increased Tpe interval and Tpe/QT ratio are associated with malignant ventricular arrhythmias. The present study hypothesized that QT and Tpe intervals are significantly prolonged in sarcoidosis patients without apparent cardiac involvement.</AbstractText>The study population consisted of 54 patients (37 female; mean age 43.4±10.6 years) under follow-up for sarcoidosis and 56 healthy subjects (37 female; mean age 42.4±8.6 years).</AbstractText>There was no statistically significant difference between the groups in maximum QT interval, QT dispersion or corrected QT (QTc) interval, but QTc dispersion and Tpe interval were significantly prolonged in the sarcoidosis group compared to the control group (QTc dispersion 59.9±22.5 and 44.4±23.8, respectively, p=0.001; Tpe interval 79.4±9.3 and 70.7±7.03, respectively, p<0.001). We also found that the Tpe/QT ratio was significantly higher in sarcoidosis patients compared to the control group (0.21±0.02 and 0.18±0.23, respectively, p<0.001).</AbstractText>Our study revealed that QTc dispersion, Tpe and Tpe/QT ratio were greater in sarcoidosis patients compared to the control group. To our knowledge, the present study is the first to use Tpe interval analysis in patients without cardiac involvement in sarcoidosis. Tpe interval and Tpe/QT ratio may be promising markers for cardiovascular morbidity and mortality due to ventricular arrhythmias in patients with and without cardiac involvement in sarcoidosis.</AbstractText>Copyright © 2017 Sociedade Portuguesa de Cardiologia. Publicado por Elsevier España, S.L.U. All rights reserved.</CopyrightInformation> |
19,853 | Diagnostic accuracy of multi-lead ECGs obtained using a pocket-sized bipolar handheld event recorder. | Handheld ECG event recorders are useful for rhythm monitoring but only record a single lead, which may limit interpretation. We sought to investigate if a multi-lead ECG may be reconstituted using this device, and aimed to evaluate diagnostic accuracy.</AbstractText>A commercially-available handheld bipolar ECG event recorder was used to reconstruct a 9-lead ECG (leads I, II and III, V1-6). Tracings were analyzed independently by a cardiologist and a fellow.</AbstractText>A total of 52 patients were evaluated. Accuracy was excellent (85-98%) for identifying atrial fibrillation, atrioventricular block, bundle branch block and left ventricular hypertrophy, but lower (77-88%) for ST-segment changes and prolonged QTc.</AbstractText>A 9-lead ECG can be reconstituted using a handheld single-lead ECG event recorder, and provides good diagnostic accuracy for common findings.</AbstractText>Copyright © 2017 Elsevier Inc. All rights reserved.</CopyrightInformation> |
19,854 | Acute and Long-term Results After Contemporary Subcutaneous Implantable Cardioverter-defibrillator Implantation: A Single-center Experience. | The subcutaneous implantable cardioverter-defibrillator (S-ICD) has emerged as an alternative to the transvenous defibrillator. The incidence of complications is similar, with inappropriate shocks (IS) being more frequent than those occurring with contemporary programming of transvenous defibrillators. Several improvements have been implemented after the S-ICD was approved for use in Europe in 2009. This study reports the results of S-ICD use in a single center, whose experience began late, at the end of 2013.</AbstractText>Prospective observational study including consecutive patients with defibrillator indication and no indication for either permanent pacing or cardiac resynchronization who underwent S-ICD implantation. Implant data and long-term follow-up were analyzed.</AbstractText>An S-ICD was implanted in 50 patients who were deemed suitable after electrocardiographic screening. The mean age was 46.9±15 (range, 15-78) years and 72% were male. Thirty eight percent had left ventricular ejection fraction ≤ 35%. The most frequent heart disease was ischemic heart disease (34%), followed by hypertrophic cardiomyopathy (18%). The intermuscular technique was used, with 3 incisions in 10% and 2 incisions in the remaining 90%. Ventricular fibrillation was induced in 49 patients, with 100% effectiveness in their conversion. After a mean follow-up of 18.1 (range, 2.3-44.8) months, there were no late complications requiring surgical revision, the rate of IS was 0%, and 1 patient (2%) experienced appropriate shocks.</AbstractText>Improvements in technology, implant technique and device programming, along with appropriate patient selection, have led to outstanding acute and long-term results, especially regarding the absence of both IS and complications requiring surgical revision.</AbstractText>Copyright © 2017 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.</CopyrightInformation> |
19,855 | Comparison of continuous compression with regular ventilations versus 30:2 compressions-ventilations strategy during mechanical cardiopulmonary resuscitation in a porcine model of cardiac arrest. | A compression-ventilation (C:V) ratio of 30:2 is recommended for adult cardiopulmonary resuscitation (CPR) by the current American Heart Association (AHA) guidelines. However, continuous chest compression (CCC) is an alternative strategy for CPR that minimizes interruption especially when an advanced airway exists. In this study, we investigated the effects of 30:2 mechanical CPR when compared with CCC in combination with regular ventilation in a porcine model.</AbstractText>Sixteen male domestic pigs weighing 39±2 kg were utilized. Ventricular fibrillation was induced and untreated for 7 min. The animals were then randomly assigned to receive CCC combined with regular ventilation (CCC group) or 30:2 CPR (VC group). Mechanical chest compression was implemented with a miniaturized mechanical chest compressor. At the same time of beginning of precordial compression, the animals were mechanically ventilated at a rate of 10 breaths-per-minute in the CCC group or with a 30:2 C:V ratio in the VC group. Defibrillation was delivered by a single 150 J shock after 5 min of CPR. If failed to resuscitation, CPR was resumed for 2 min before the next shock. The protocol was stopped if successful resuscitation or at a total of 15 min. The resuscitated animals were observed for 72 h.</AbstractText>Coronary perfusion pressure, end-tidal carbon dioxide and carotid blood flow in the VC group were similar to those achieved in the CCC group during CPR. No significant differences were observed in arterial blood gas parameters between two groups at baseline, VF 6 min, CPR 4 min and 30, 120 and 360 min post-resuscitation. Although extravascular lung water index of both groups significantly increased after resuscitation, no distinct difference was found between CCC and VC groups. All animals were successfully resuscitated and survived for 72 h with favorable neurologic outcomes in both groups. However, obviously more numbers of rib fracture were observed in CCC animals in comparison with VC animals.</AbstractText>There was no difference in hemodynamic efficacy and gas exchange during and after resuscitation, therefore identical 72 h survival with intact neurologic function was observed in both VC and CCC groups. However, the incidence of rib fracture increases during the mechanical CPR strategy of CCC combined with regular ventilations.</AbstractText> |
19,856 | Tpeak-Tend interval during therapeutic hypothermia can predict upcoming ventricular fibrillation in subjects with aborted arrhythmic sudden cardiac death: 3-years follow-up results. | Prolonged Tpeak-Tend interval has been shown to be markers of arrhythmogenesis in various cardiac disorders. However, its dynamicity is one of the obstacles to predict fatal ventricular arrhythmia. This study investigated whether Tpeak-Tend interval during therapeutic hypothermia (TH) is associated with ventricular fibrillation (VF) inducibility and clinical arrhythmia in subjects with aborted arrhythmic sudden cardiac death (SCD).</AbstractText>The study group included 31 patients (24 males, age 39.1 ± 17.6 years) presenting with arrhythmic SCD in whom Tpeak-Tend interval and J-wave amplitude were measured in electrocardiogram (ECG) of the earliest medical contact and during TH; these patients underwent programmed ventricular stimulation. The summation of J-wave amplitude and QTc interval increased during TH. However, it was not associated with VF inducibility. Patients with inducible VF showed a small Tpeak-Tend interval dispersion in the baseline 12-lead ECG (68.8 ± 24.7 vs. 94.0 ± 55.6 ms, P = 0.044) and a marked increase of the dispersion during the TH (36.2 ± 51.2 vs. -6.1 ± 45.5 ms, P = 0.039). Twenty-four patients underwent implantable cardioverter defibrillator (ICD) implantation. Among them, the patients with long QTc, Tpeak-Tend, and precordial Tpeak-Tend during the TH developed VF more frequently (QTc, 511.9 ± 53.71 ms vs. 566.5 ± 56.08 ms, P = 0.038; Tpeak-Tend interval, 145.6 ± 38.4 ms vs. 185.7 ± 49.95 ms, P = 0.048; precordial Tpeak-Tend interval, 139.3 ± 35.11 ms vs. 185.7 ± 49.95 ms, P = 0.018). The initial VF inducibility was not related with the VF development in follow-up.</AbstractText>In patients with aborted arrhythmic SCD, long Tpeak-Tend interval and QTc interval during TH could predict VF development in their follow-up.</AbstractText>Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For permissions, please email: journals.permissions@oup.com.</CopyrightInformation> |
19,857 | Atrioventricular node ablation and His bundle pacing. | Atrioventricular node ablation (AVNA) and right ventricular pacing (RVP) are effective therapies for patients with atrial fibrillation (AF) and rapid ventricular rates. His bundle pacing (HBP) is a physiologic alternative to RVP. The aim of our study is to assess the feasibility and safety of HBP in patients undergoing AVNA and its effect on left ventricular (LV) function.</AbstractText>Permanent HBP is the preferred form of ventricular pacing at our institute. Atrioventricular node ablation and HBP were performed in patients with AF and difficulty in rate control. His bundle pacing implant characteristics and thresholds were recorded. Fluoroscopic relationship of AVNA site to HBP lead electrodes was documented. Left ventricular ejection fraction (LVEF) and New York Heart Association (NYHA) functional class at baseline and during follow-up were assessed. Forty-two patients underwent HBP and AVNA: age 74 ± 11 years; men 45%; HTN 64%; DM 19%; CAD 36%; permanent AF 40%; cardiomyopathy 55%. His bundle pacing was successful in 40 of 42 patients (95%). Successful AVNA site was at or below the ring electrode in 22 (no acute change in HBP threshold); above the ring electrode in 13 and left side in 2 pts (acute increase in HBP threshold in 7 of 15 pts). Final HBP threshold at implant was 1 ± 0.8 V@1 ms and increased to 1.6 ± 1.2 V@1 ms during a mean follow-up of 19 ± 14 months. Left ventricular ejection fraction increased from 43 ± 13% to 50 ± 11% (P = 0.01). New York Heart Association functional status improved from 2.5 ± 0.5 to 1.9 ± 0.5 (P = 0.04).</AbstractText>Atrioventricular node ablation and HBP were successful in 95% of patients. His bundle pacing lead characteristics remained relatively stable. Left ventricular ejection fraction improved significantly during follow-up. His bundle pacing is feasible, safe and effective in pts undergoing AVNA.</AbstractText>Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For permissions, please email: journals.permissions@oup.com.</CopyrightInformation> |
19,858 | Synergistic Anti-arrhythmic Effects in Human Atria with Combined Use of Sodium Blockers and Acacetin. | Atrial fibrillation (AF) is the most common cardiac arrhythmia. Developing effective and safe anti-AF drugs remains an unmet challenge. Simultaneous block of both atrial-specific ultra-rapid delayed rectifier potassium (K<sup>+</sup>) current (I<sub>Kur</sub>) and the Na<sup>+</sup> current (I<sub>Na</sub>) has been hypothesized to be anti-AF, without inducing significant QT prolongation and ventricular side effects. However, the antiarrhythmic advantage of simultaneously blocking these two channels vs. individual block in the setting of AF-induced electrical remodeling remains to be documented. Furthermore, many I<sub>Kur</sub> blockers such as acacetin and AVE0118, partially inhibit other K<sup>+</sup> currents in the atria. Whether this multi-K<sup>+</sup>-block produces greater anti-AF effects compared with selective I<sub>Kur</sub>-block has not been fully understood. The aim of this study was to use computer models to (i) assess the impact of multi-K<sup>+</sup>-block as exhibited by many I<sub>Kur</sub> blokers, and (ii) evaluate the antiarrhythmic effect of blocking I<sub>Kur</sub> and I<sub>Na</sub>, either alone or in combination, on atrial and ventricular electrical excitation and recovery in the setting of AF-induced electrical-remodeling. Contemporary mathematical models of human atrial and ventricular cells were modified to incorporate dose-dependent actions of acacetin (a multichannel blocker primarily inhibiting I<sub>Kur</sub> while less potently blocking I<sub>to</sub>, I<sub>Kr</sub>, and I<sub>Ks</sub>). Rate- and atrial-selective inhibition of I<sub>Na</sub> was also incorporated into the models. These single myocyte models were then incorporated into multicellular two-dimensional (2D) and three-dimensional (3D) anatomical models of the human atria. As expected, application of I<sub>Kur</sub> blocker produced pronounced action potential duration (APD) prolongation in atrial myocytes. Furthermore, combined multiple K<sup>+</sup>-channel block that mimicked the effects of acacetin exhibited synergistic APD prolongations. Synergistically anti-AF effects following inhibition of I<sub>Na</sub> and combined I<sub>Kur</sub>/K<sup>+</sup>-channels were also observed. The attainable maximal AF-selectivity of I<sub>Na</sub> inhibition was greatly augmented by blocking I<sub>Kur</sub> or multiple K<sup>+</sup>-currents in the atrial myocytes. This enhanced anti-arrhythmic effects of combined block of Na<sup>+</sup>- and K<sup>+</sup>-channels were also seen in 2D and 3D simulations; specially, there was an enhanced efficacy in terminating re-entrant excitation waves, exerting improved antiarrhythmic effects in the human atria as compared to a single-channel block. However, in the human ventricular myocytes and tissue, cellular repolarization and computed QT intervals were modestly affected in the presence of actions of acacetin and I<sub>Na</sub> blockers (either alone or in combination). In conclusion, this study demonstrates synergistic antiarrhythmic benefits of combined block of I<sub>Kur</sub> and I<sub>Na</sub>, as well as those of I<sub>Na</sub> and combined multi K<sup>+</sup>-current block of acacetin, without significant alterations of ventricular repolarization and QT intervals. This approach may be a valuable strategy for the treatment of AF. |
19,859 | Catheter Ablation of Ventricular Tachycardia in Structural Heart Disease: Indications, Strategies, and Outcomes-Part II. | In contrast to ventricular tachycardia (VT) that occurs in the setting of a structurally normal heart, VT that occurs in patients with structural heart disease carries an elevated risk for sudden cardiac death (SCD), and implantable cardioverter-defibrillators (ICDs) are the mainstay of therapy. In these individuals, catheter ablation may be used as adjunctive therapy to treat or prevent repetitive ICD therapies when antiarrhythmic drugs are ineffective or not desired. However, certain patients with frequent premature ventricular contractions (PVCs) or VT and tachycardiomyopathy should be considered for ablation before ICD implantation because left ventricular function may improve, consequently decreasing the risk of SCD and obviating the need for an ICD. The goal of this paper is to review the pathophysiology, mechanism, and management of VT in the setting of structural heart disease and discuss the evolving role of catheter ablation in decreasing ventricular arrhythmia recurrence. |
19,860 | Catheter Ablation of Ventricular Tachycardia in Structurally Normal Hearts: Indications, Strategies, and Outcomes-Part I. | Catheter ablation of ventricular tachycardia (VT) is being increasingly performed; yet, there is often confusion regarding indications, outcomes, and how to identify those patient populations most likely to benefit. The management strategy differs between those with structural heart disease and those without. For the former, an implantable cardioverter-defibrillator (ICD) is typically required due to an elevated risk for sudden cardiac death, and catheter ablation can be used as adjunctive therapy to treat or prevent repetitive ICD therapies. In contrast, VT or premature ventricular contractions in the setting of a structurally normal heart carries a low risk for sudden cardiac death; accordingly, there is typically no indication for an ICD. In these patients, catheter ablation is considered for symptom management or to treat tachycardiomyopathy and is potentially curative. Here, the authors discuss the pathophysiology, mechanism, and management of VT that occurs in the setting of a structurally normal heart and the role of catheter ablation. |
19,861 | [Tea polyphenols down-regulate JNK phosphorylation to inhibit neuron apoptosis in rats with cardiac arrest]. | To study the effect of tea polyphenols (TP) on c-Jun N-terminal kinase 1/2 (JNK1/2) phosphorylation and cell apoptosis in brain tissues in rats with cardiac arrest (CA) following cardiopulmonary resuscitation (CPR).</AbstractText>Healthy male Sprague-Dawley (SD) rats were randomly divided into sham group (n = 6), CA group (n = 12), and TP group (n = 12). The rats in CA and TP groups were induced ventricular fibrillation (VF) via esophagus stimulation with alternating current. Five minutes after CA, CPR was performed. Once restoration of spontaneous circulation (ROSC) was gained, normal saline (NS) and TP were injected intravenously in CA and TP groups with 10 mg/kg, respectively. Cortex of 6 rats in each group was harvested at 12 hours and 72 hours after ROSC. Cortex of sham group was harvested at 72 hours after operation without VF induction. The expressions of phosphorylated JNK1/2 (p-JNK1/2), JNK1/2, caspase-3, Bax and Bcl-2 were measured by Western Blot. Cell apoptosis was detected by TdT-mediated dUTP nick end labeling (TUNEL), and p-JNK/TUNEL double positive cells were detected by fluorescence double staining.</AbstractText>Compared with sham group, the expressions of p-JNK, caspase-3 and Bax were increased, the expression of Bcl-2 was declined, and the apoptotic cells were significantly increased at 72 hours after ROSC in CA group. Compared with CA group, the phosphorylation of JNK was significantly declined at 12 hours and 72 hours after ROSC in TP group (the ratio of p-JNK1/2 and JNK1/2: 3.200±0.060 vs. 5.700±0.210, 1.400±0.060 vs. 5.400±0.090, both P < 0.05), the expressions of caspase-3 and Bax were decreased [caspase-3 (gray value): 42.00±5.23 vs. 54.00±7.84, 38.74±4.60 vs. 58.68±7.19; Bax (gray value): 38.04±6.21 vs. 68.76±6.08, 58.84±7.99 vs. 70.03±7.36, all P < 0.05], the expression of Bcl-2 was increased (gray value: 37.36±3.11 vs. 28.47±7.46, 48.78±6.55 vs. 29.54±3.13, both P < 0.05); the cell apoptosis rate was reduced at 72 hours [(31.14±4.51)% vs. (45.87±3.95)%, P < 0.01], and p-JNK/TUNEL double positive cells/TUNEL cells ratio was significantly decreased (10.00±0.85 vs. 52.70±3.05, P < 0.01).</AbstractText>The inhibition of neuron apoptosis caused by TP after CPR in rats with CA is related to the inhibition of JNK1/2 phosphorylation.</AbstractText> |
19,862 | Effects of early afterdepolarizations on excitation patterns in an accurate model of the human ventricles. | Early Afterdepolarizations, EADs, are defined as the reversal of the action potential before completion of the repolarization phase, which can result in ectopic beats. However, the series of mechanisms of EADs leading to these ectopic beats and related cardiac arrhythmias are not well understood. Therefore, we aimed to investigate the influence of this single cell behavior on the whole heart level. For this study we used a modified version of the Ten Tusscher-Panfilov model of human ventricular cells (TP06) which we implemented in a 3D ventricle model including realistic fiber orientations. To increase the likelihood of EAD formation at the single cell level, we reduced the repolarization reserve (RR) by reducing the rapid delayed rectifier Potassium current and raising the L-type Calcium current. Varying these parameters defined a 2D parametric space where different excitation patterns could be classified. Depending on the initial conditions, by either exciting the ventricles with a spiral formation or burst pacing protocol, we found multiple different spatio-temporal excitation patterns. The spiral formation protocol resulted in the categorization of a stable spiral (S), a meandering spiral (MS), a spiral break-up regime (SB), spiral fibrillation type B (B), spiral fibrillation type A (A) and an oscillatory excitation type (O). The last three patterns are a 3D generalization of previously found patterns in 2D. First, the spiral fibrillation type B showed waves determined by a chaotic bi-excitable regime, i.e. mediated by both Sodium and Calcium waves at the same time and in same tissue settings. In the parameter region governed by the B pattern, single cells were able to repolarize completely and different (spiral) waves chaotically burst into each other without finishing a 360 degree rotation. Second, spiral fibrillation type A patterns consisted of multiple small rotating spirals. Single cells failed to repolarize to the resting membrane potential hence prohibiting the Sodium channel gates to recover. Accordingly, we found that Calcium waves mediated these patterns. Third, a further reduction of the RR resulted in a more exotic parameter regime whereby the individual cells behaved independently as oscillators. The patterns arose due to a phase-shift of different oscillators as disconnection of the cells resulted in continuation of the patterns. For all patterns, we computed realistic 9 lead ECGs by including a torso model. The B and A type pattern exposed the behavior of Ventricular Tachycardia (VT). We conclude that EADs at the single cell level can result in different types of cardiac fibrillation at the tissue and 3D ventricle level. |
19,863 | Novel Mutation in <i>FLNC</i> (Filamin C) Causes Familial Restrictive Cardiomyopathy. | Restrictive cardiomyopathy (RCM) is a rare cardiomyopathy characterized by impaired diastolic ventricular function resulting in a poor clinical prognosis. Rarely, heritable forms of RCM have been reported, and mutations underlying RCM have been identified in genes that govern the contractile function of the cardiomyocytes.</AbstractText>We evaluated 8 family members across 4 generations by history, physical examination, electrocardiography, and echocardiography. Affected individuals presented with a pleitropic syndrome of progressive RCM, atrioventricular septal defects, and a high prevalence of atrial fibrillation. Exome sequencing of 5 affected members identified a single novel missense variant in a highly conserved residue of FLNC (filamin C; p.V2297M). FLNC</i> encodes filamin C-a protein that acts as both a scaffold for the assembly and organization of the central contractile unit of striated muscle and also as a mechanosensitive signaling molecule during cell migration and shear stress. Immunohistochemical analysis of FLNC localization in cardiac tissue from an affected family member revealed a diminished localization at the z disk, whereas traditional localization at the intercalated disk was preserved. Stem cell-derived cardiomyocytes mutated to carry the effect allele had diminished contractile activity when compared with controls.</AbstractText>We have identified a novel variant in FLNC</i> as pathogenic variant for familial RCM-a finding that further expands on the genetic basis of this rare and morbid cardiomyopathy.</AbstractText>© 2017 American Heart Association, Inc.</CopyrightInformation> |
19,864 | Novel Desmin Mutation p.Glu401Asp Impairs Filament Formation, Disrupts Cell Membrane Integrity, and Causes Severe Arrhythmogenic Left Ventricular Cardiomyopathy/Dysplasia. | Desmin (DES</i>) mutations cause severe skeletal and cardiac muscle disease with heterogeneous phenotypes. Recently, DES</i> mutations were described in patients with inherited arrhythmogenic right ventricular cardiomyopathy/dysplasia, although their cellular and molecular pathomechanisms are not precisely known. Our aim is to describe clinically and functionally the novel DES</i>-p.Glu401Asp mutation as a cause of inherited left ventricular arrhythmogenic cardiomyopathy/dysplasia.</AbstractText>We identified the novel DES</i> mutation p.Glu401Asp in a large Spanish family with inherited left ventricular arrhythmogenic cardiomyopathy/dysplasia and a high incidence of adverse cardiac events. A full clinical evaluation was performed on all mutation carriers and noncarriers to establish clinical and genetic cosegregation. In addition, desmin, and intercalar disc-related proteins expression were histologically analyzed in explanted cardiac tissue affected by the DES</i> mutation. Furthermore, mesenchymal stem cells were isolated and cultured from 2 family members with the DES</i> mutation (1 with mild and 1 with severe symptomatology) and a member without the mutation (control) and differentiated ex vivo to cardiomyocytes. Then, important genes related to cardiac differentiation and function were analyzed by real-time quantitative polymerase chain reaction. Finally, the p.Glu401Asp mutated DES</i> gene was transfected into cell lines and analyzed by confocal microscopy.</AbstractText>Of the 66 family members screened for the DES</i>-p.Glu401Asp mutation, 23 of them were positive, 6 were obligate carriers, and 2 were likely carriers. One hundred percent of genotype-positive patients presented data consistent with inherited arrhythmogenic cardiomyopathy/dysplasia phenotype with variable disease severity expression, high-incidence of sudden cardiac death, and absence of skeletal myopathy or conduction system disorders. Immunohistochemistry was compatible with inherited arrhythmogenic cardiomyopathy/dysplasia, and the functional study showed an abnormal growth pattern and cellular adhesion, reduced desmin RNA expression, and some other membrane proteins, as well, and desmin aggregates in transfected cells expressing the mutant desmin.</AbstractText>The DES</i>-p.Glu401Asp mutation causes predominant inherited left ventricular arrhythmogenic cardiomyopathy/dysplasia with a high incidence of adverse clinical events in the absence of skeletal myopathy or conduction system disorders. The pathogenic mechanism probably corresponds to an alteration in desmin dimer and oligomer assembly and its connection with membrane proteins within the intercalated disc.</AbstractText>© 2017 American Heart Association, Inc.</CopyrightInformation> |
19,865 | Mayo registry for telemetry efficacy in arrest study: An evaluation of the feasibility of the do not intubate code status. | <b>Introduction:</b> Guidelines recommend discussing code status with patients on hospital admission. No study has evaluated the feasibility of a full code with do not intubate (DNI) status. <b>Methods:</b> A retrospective analysis of patients who experienced a cardiopulmonary arrest was performed between May 1, 2008 and June 20, 2014. A descriptive analysis was created based on whether patients required mechanical ventilatory support during the hospitalization and comparisons were made between both patient subsets. <b>Results:</b> A total of 239 patients were included. Almost all (n = 218, 91.2%) required intubation during the hospitalization. Over half (n = 117, 53.7%) were intubated on the same day as the cardiopulmonary arrest and 91 patients (41.7%) were intubated at the time of arrest. Comparisons between intubated and non-intubated patients showed little differences in clinical characteristics, except for a higher proportion of medical cardiac etiology for admission in patients who did not require intubation (n = 10, 47.6% versus n = 55, 25.2%; <i>p</i> = 0.18) and initial arrest rhythm of ventricular tachycardia/fibrillation (n = 8, 38.1% versus n = 50, 22.9%; <i>p </i>= 0.37). No differences in 24-hour and posthospital survivals were present. <b>Conclusion:</b> Mechanical ventilatory support is commonly utilized in patients who experience a cardiopulmonary arrest. The DNI status may not be a feasible code status option for most patients. |
19,866 | Fatal butane toxicity and delayed onset of refractory ventricular fibrillation. | A 30-year-old male was presented to the Emergency Department (ED) by the Emergency Medical Services (EMS). He was found unconscious but breathing normally, and had a seizure for more than 30 minutes. He was no previous history of systemic disease, previous operation, medication and any known allergy. According to the witnesses, he was alone in the coffee shop, and besides him was a lighter refill canister containing 250 ml extra purified butane gas, and he suddenly collapsed and had seizure. Six hours later, he developed ventricular fibrillation and he was not responding to amiodarone infusion, and 4 times defibrillation and cardioversion. He died after 45 minutes of resuscitation. |
19,867 | Right ventricular exercise contractile reserve and outcomes after early surgery for primary mitral regurgitation. | To assess if the lack of development of right ventricular (RV) contractile reserve during exercise echocardiography (ex-echo) might be a predictor of postoperative major adverse cardiovascular events (MACEs) in patients with primary mitral regurgitation (pMR) undergoing early surgery.</AbstractText>Comprehensive resting and ex-echo were performed in 142 asymptomatic patients (58±21 years, 68% men, New York Heart Association functional class ≤2) with isolated severe pMR and preserved left ventricular (LV) function (LV ejection >60%, LV end-systolic diameter <45 mm) undergoing mitral valve replacement (n=20) or repair. Postoperative MACEs were defined as occurrence of atrial fibrillation, stroke, cardiac-related hospitalisation or death. RV function was evaluated at rest in every patient during ex-echo by measuring their tricuspid annular plane systolic excursion (TAPSE) value.</AbstractText>After median follow-up of 30 months (IQR 16-60 months), MACEs occurred in 48 (34%) patients. Using Bayesian model averaging, among all the characteristics including the type of surgery, exercise TAPSE (ex-TAPSE) emerged as the most likely predictor of prognosis (HR 0.91, 95% CI 0.86 to 0.96). Other probable predictors were exercise fractional area change (HR 0.02, 95% CI 0.00 to 0.80), male gender (HR 0.40, 95% CI 0.21 to 0.75) and RV basal diameter (HR 1.06, 95% CI 0.98 to 1.14). In the receiver operating characteristic curve analysis, an ex-TAPSE value of <26 mm (sensitivity 73% (95% CI 61 to 84) and specificity of 86% (95% CI 77% to 93%)) defined RV dysfunction. Event-free survival at 5 years was significantly lower in the patient group that exhibited no development of RV contractile reserve during exercise: 43.9% (95% CI 31.3 to 61.4) vs 75.8% (95% CI 64.8 to 88.7).</AbstractText>Lack of development of exercise-induced RV contractile reserve is a prognostic predictor in patients with severe pMR undergoing early mitral valve surgery.</AbstractText>© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.</CopyrightInformation> |
19,868 | Differences in Approaches and Outcomes of Defibrillator Lead Implants Between High-Volume and Low-Volume Operators: Results From the Pacemaker and Implantable Defibrillator Leads Survival Study ("PAIDLESS"). | The purpose of this study was to investigate the relationship between operator volume and implantable defibrillator lead failure and patient mortality at a single large implanting center.</AbstractText>This study analyzed the differences between high-volume and low-volume defibrillator implanters in the Pacemaker and Implantable Defibrillator Lead Survival Study ("PAIDLESS") between February 1, 1996 and December 31, 2011 at NYU Winthrop Hospital. "High-volume" was defined as performing ≥500 implants over the study period, while "low-volume" was defined as performing <500 implants. Comparisons between the procedure volume groups were performed using Fisher's Exact test, Wilcoxon rank-sum test, and Kaplan-Meier analysis as appropriate.</AbstractText>Eight operators participated in the study, four of whom were high-volume operators. Of 3801 patients, a total of 3149 (83%) were operated upon by high-volume operators. Low-volume operators implanted fewer recalled leads (12% vs 42%; P<.001) and more often obtained venous access through the cephalic vein cutdown approach (63% vs 38%; P<.001) than high-volume operators. Kaplan-Meier analysis revealed shorter time to lead failure in the low-volume group (P=.02). Time to mortality was not significantly different between the high-volume and low-volume groups (P=.18). When adjusted for lead recall status, patients of high-volume operators were 43% less likely to experience lead failure compared to patients of low-volume operators.</AbstractText>High-volume defibrillator implanters selected a higher percentage of recalled leads, but their patients were less likely to encounter lead failure when adjusted for lead recall status compared to low-volume operators.</AbstractText> |
19,869 | Repetitive-incessant electrical storm triggered by early repolarization. | Early repolarization syndrome (ERS) was originally considered a normal variant with benign outcome. However, recent studies have demonstrated that it can be linked to a considerable risk of life-threatening arrhythmias and sudden cardiac death. We report a case with an extraordinary, extremely malignant clinical expression of ERS refractory to all antiarrhythmic drugs including quinidine. This case demonstrates real-time changes of dynamic electrocardiogram (ECG) preceding a polymorphic ventricular tachycardia (VT)-ventricular fibrillation (VF) and possible external factors triggering arrhythmia onset. Implantable cardioverter-defibrillator (ICD) function was terminated 6 months after implantation due to multiple-incessant electrical storm (ES). Catheter ablation was the definite treatment of this malignant entity. |
19,870 | Retrospective Evaluation of the Effect of Heart Rate on Survival in Dogs with Atrial Fibrillation. | Atrial fibrillation (AF) usually is associated with a rapid ventricular rate. The optimal heart rate (HR) during AF is unknown.</AbstractText><AbstractText Label="HYPOTHESIS/OBJECTIVES" NlmCategory="OBJECTIVE">Heart rate affects survival in dogs with chronic AF.</AbstractText>Forty-six dogs with AF and 24-hour ambulatory recordings were evaluated.</AbstractText>Retrospective study. Holter-derived HR variables were analyzed as follows: mean HR (meanHR, 24-hour average), minimum HR (minHR, 1-minute average), maximum HR (maxHR, 1-minute average). Survival times were recorded from the time of presumed adequate rate control. The primary endpoint was all-cause mortality. Cox proportional hazards analysis identified variables independently associated with survival; Kaplan-Meier survival analysis estimated the median survival time of dogs with meanHR <125 bpm versus ≥125 bpm.</AbstractText>All 46 dogs had structural heart disease; 31 of 46 had congestive heart failure (CHF), 44 of 46 received antiarrhythmic drugs. Of 15 dogs with cardiac death, 14 had CHF. Median time to all-cause death was 524 days (Interquartile range (IQR), 76-1,037 days). MeanHR was 125 bpm (range, 62-203 bpm), minHR was 82 bpm (range, 37-163 bpm), maxHR was 217 bpm (range, 126-307 bpm). These were significantly correlated with all-cause and cardiac-related mortality. For every 10 bpm increase in meanHR, the risk of all-cause mortality increased by 35% (hazard ratio, 1.35; 95% CI, 1.17-1.55; P < 0.001). Median survival time of dogs with meanHR<125 bpm (n = 23) was significantly longer (1,037 days; range, 524-open) than meanHR ≥125 bpm (n = 23; 105 days; range, 67-267 days; P = 0.0012). Mean HR was independently associated with all-cause and cardiovascular mortality (P < 0.003).</AbstractText>Holter-derived meanHR affects survival in dogs with AF. Dogs with meanHR <125 bpm lived longer than those with meanHR ≥ 125 bpm.</AbstractText>Copyright © 2017 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.</CopyrightInformation> |
19,871 | Efficacy of amiodarone and lidocaine for preventing ventricular fibrillation after aortic cross-clamp release in open heart surgery: a meta-analysis of randomized controlled trials. | The relative preventative efficacy of amiodarone and lidocaine for ventricular fibrillation (VF) after release of an aortic cross-clamp (ACC) during open heart surgery has not been determined. This meta-analysis was designed to systematically evaluate the influence of amiodarone, lidocaine, or placebo on the incidence of VF after ACC.</AbstractText>Prospective randomized controlled trials (RCTs) that compared the VF-preventative effects of amiodarone with lidocaine, or amiodarone or lidocaine with placebo were included. PubMed, EMBASE, and the Cochrane Library were searched for relevant RCTs. Fixed or randomized effect models were applied according to the heterogeneity of the data from the selected studies.</AbstractText>We included eight RCTs in the analysis. Pooled results suggested that the preventative effects of amiodarone and lidocaine were comparable (relative risk (RR)=1.12, 95% confidence interval (CI): 0.70 to 1.80, P=0.63), but both were superior to the placebo (amiodarone, RR=0.71, 95% CI: 0.51 to 1.00, P=0.05; lidocaine, RR=0.63, 95% CI: 0.46 to 0.88, P=0.006). The percentage of patients requiring electric defibrillation counter shocks (DCSs) did not differ significantly among patients administered amiodarone (RR=0.21, 95% CI: 0.04 to 1.19, P=0.08), lidocaine (RR=2.44, 95% CI: 0.13 to 44.02, P=0.55), or the placebo (RR=0.56, 95% CI: 0.25 to 1.25, P=0.16).</AbstractText>Amiodarone and lidocaine are comparably effective in preventing VF after ACC, but the percentage of patients who subsequently require DCSs does not differ among those administered amiodarone, lidocaine, or placebo.</AbstractText> |
19,872 | Comparison of blood pressure monitoring by applanation tonometry and invasively assessed blood pressure in cardiological patients. | The aim of this study was to evaluate the accuracy and precision of non-invasive continuous blood pressure measurement by applanation tonometry (AT) in awake or anaesthetised cardiological intensive care patients. Patients suffering from highly impaired left ventricular function atrial fibrillation or severe aortic valve stenosis were included into the study. Arterial blood pressure was recorded by applanation tonometry (T-Line 400, Tensys Medical<sup>®</sup>, USA) and an arterial line in awake or anaesthetised patients. Discrepancies in mean (MAP), systolic (SAP), and diastolic (DAP) arterial pressure between the two methods were assessed as bias, limits of agreement and percentage error respectively. In 31 patients a total of 27,900 measurements were analyzed. The concordance correlation coefficient was 0.23, 0.45 and 0.06 for MAP, SAP and DAP, respectively. For all patients bias for MAP<sub>AT</sub> compared to MAP<sub>AL</sub> was 14.96 mmHg (SAP<sub>AT</sub> 4.51 mmHg; DAP<sub>AT</sub> 19.12 mmHg) with limits of agreement for MAP<sub>AT</sub> of 46.25 and - 16.33 mm Hg (SAP<sub>AT</sub> 48.00 and - 38.98 mmHg; DAP<sub>AT</sub> 50.12 and - 11.89 mmHg). Percentage error for MAP<sub>AT</sub> was 56.8% (42.7% for SAP<sub>AT</sub>; 75.2% for DAP<sub>AT</sub>). We conclude that the AT method is not reliable in ICU patients with severe cardiac comorbidities. |
19,873 | Echocardiography and cardiac arrhythmias. | Cardiac arrhythmias refer to any abnormality or disturbance in the normal activation sequence of the myocardium and may be indicative of structural heart disease and the cause of significant cardiovascular complications and sudden cardiac death. The following review summarizes the current state-of-the-art knowledge on the role of echocardiography in the management of cardiac arrhythmias and focuses on atrial fibrillation and ventricular arrhythmias where echocardiography presents a particular diagnostic and prognostic interest. Moreover, a brief reference is made to the effect of cardiac arrhythmias and conduction abnormalities on echocardiographic examination. |
19,874 | Rhythm and rate control of atrial fibrillation in the emergency department - A large community-based observational study. | Atrial fibrillation (AF) is the most common arrhythmia presentation to the emergency department (ED) and frequently results in admission to the hospital. Although rarely life-threatening and not usually an emergent condition, AF places a large burden on our health-care system. The objective of this study was to describe the practices of ED physicians in the management of AF in a large urban Canadian city.</AbstractText>From January 1, 2010 to December 31, 2010, patients with a primary diagnosis of AF were identified across 10 EDs in Toronto, Canada (N=2,609). Fifty patients were selected at random from each hospital for a detailed chart review (n=500).</AbstractText>Two hundred thirty-two patients (46%) received rate control, and 129 (26%) received rhythm control with the remainder (28%) receiving neither therapy. Sixty-seven percent of patients were discharged home. Most patients (79%) were symptomatic on arrival; however, only a minority of these (31%) received rhythm control. Factors that were associated with rhythm control included younger age, duration of palpitations ≤ 48 hours, a lower CHADS2 score, and the absence of left ventricular dysfunction.</AbstractText>Our data suggest a wide range of practice amongst ED physicians treating patients presenting to the ED with a primary diagnosis of AF. A randomized trial is needed to better understand the optimal management strategy in this patient population and setting.</AbstractText> |
19,875 | H558R, a common SCN5A polymorphism, modifies the clinical phenotype of Brugada syndrome by modulating DNA methylation of SCN5A promoters. | A common SCN5A polymorphism H558R (c.1673 A > G, rs1805124) improves sodium channel activity in mutated channels and known to be a genetic modifier of Brugada syndrome patients (BrS). We investigated clinical manifestations and underlying mechanisms of H558R in BrS.</AbstractText>We genotyped H558R in 100 BrS (mean age 45 ± 14 years; 91 men) and 1875 controls (mean age 54 ± 18 years; 1546 men). We compared clinical parameters in BrS with and without H558R (H558R+ vs. H558R- group, N = 9 vs. 91). We also obtained right atrial sections from 30 patients during aortic aneurysm operations and compared SCN5A expression and methylation with or without H558R. H558R was less frequent in BrS than controls (9.0% vs. 19.2%, P = 0.028). The VF occurrence ratio was significantly lower (0% vs. 29.7%, P = 0.03) and spontaneous type 1 ECG was less observed in H558R+ than H558R- group (33.3% vs. 74.7%, P = 0.01). The SCN5A expression level was significantly higher and the methylation rate was significantly lower in sections with H558R (N = 10) than those without (0.98 ± 0.14 vs. 0.83 ± 0.19, P = 0.04; 0.7 ± 0.2% vs. 1.6 ± 0.1%, P = 0.004, respectively). In BrS with heterozygous H558R, the A allele mRNA expression was 1.38 fold higher than G allele expression.</AbstractText>The SCN5A polymorphism H558R may be a modifier that protects against VF occurrence in BrS. The H558R decreased the SCN5A promoter methylation and increased the expression level in cardiac tissue. An allelic expression imbalance in BrS with a heterozygous H558R may also contribute to the protective effects in heterozygous mutations.</AbstractText> |
19,876 | Proinflammatory Cytokines Are Soluble Mediators Linked with Ventricular Arrhythmias and Contractile Dysfunction in a Rat Model of Metabolic Syndrome. | Metabolic syndrome (MS) increases cardiovascular risk and is associated with cardiac dysfunction and arrhythmias, although the precise mechanisms are still under study. Chronic inflammation in MS has emerged as a possible cause of adverse cardiac events. Male Wistar rats fed with 30% sucrose in drinking water and standard chow for 25-27 weeks were compared to a control group. The MS group showed increased weight, visceral fat, blood pressure, and serum triglycerides. The most important increases in serum cytokines included IL-1<i>β</i> (7-fold), TNF-<i>α</i> (84%), IL-6 (41%), and leptin (2-fold), the latter also showing increased gene expression in heart tissue (35-fold). Heart function ex vivo in MS group showed a decreased mechanical performance response to isoproterenol challenge (ISO). Importantly, MS hearts under ISO showed nearly twofold the incidence of ventricular fibrillation. Healthy rat cardiomyocytes exposed to MS group serum displayed impaired contractile function and Ca<sup>2+</sup> handling during ISO treatment, showing slightly decreased cell shortening and Ca<sup>2+</sup> transient amplitude (23%), slower cytosolic calcium removal (17%), and more frequent spontaneous Ca<sup>2+</sup> release events (7.5-fold). As spontaneous Ca<sup>2+</sup> releases provide a substrate for ventricular arrhythmias, our study highlights the possible role of serum proinflammatory mediators in the development of arrhythmic events during MS. |
19,877 | Reduced Left Ventricular Global Longitudinal Strain Predicts Prolonged Hospitalization: A Cohort Analysis of Patients Having Aortic Valve Replacement Surgery. | Left ventricular ejection fraction (LVEF) is often preserved in patients with aortic stenosis and thus cannot distinguish between normal myocardial contractile function and subclinical dysfunction. Global longitudinal strain and strain rate (SR), which measure myocardial deformation, are robust indicators of myocardial function and can detect subtle myocardial dysfunction that is not apparent with conventional echocardiographic measures. Strain and SR may better predict postoperative outcomes than LVEF. The primary aim of our investigation was to assess the association between global longitudinal strain and serious postoperative outcomes in patients with aortic stenosis having aortic valve replacement. Secondarily, we also assessed the associations between global longitudinal SR and LVEF and the outcomes.</AbstractText>In this post hoc analysis of data from a randomized clinical trial (NCT01187329), we examined the association between measures of myocardial function and the following outcomes: (1) need for postoperative inotropic/vasopressor support; (2) prolonged hospitalization (>7 days); and (3) postoperative atrial fibrillation. Standardized transesophageal echocardiographic examinations were performed after anesthetic induction. Myocardial deformation was measured using speckle-tracking echocardiography. Multivariable logistic regression was used to assess associations between measures of myocardial function and outcomes, adjusted for potential confounding factors. The predictive ability of global longitudinal strain, SR, and LVEF was assessed as area under receiver operating characteristics curves (AUCs).</AbstractText>Of 100 patients enrolled in the clinical trial, 86 patients with aortic stenosis had acceptable images for global longitudinal strain analysis. Primarily, worse intraoperative global longitudinal strain was associated with prolonged hospitalization (odds ratio [98.3% confidence interval], 1.22 [1.01-1.47] per 1% decrease [absolute value] in strain; P = .012), but not with other outcomes. Secondarily, worse global longitudinal SR was associated with prolonged hospitalization (odds ratio [99.7% confidence interval], 1.68 [1.01-2.79] per 0.1 second(-1) decrease [absolute value] in SR; P = .003), but not other outcomes. LVEF was not associated with any outcomes. Global longitudinal SR was the best predictor for prolonged hospitalization (AUC, 0.72), followed by global longitudinal strain (AUC, 0.67) and LVEF (AUC, 0.62).</AbstractText>Global longitudinal strain and SR are useful predictors of prolonged hospitalization in patients with aortic stenosis having an aortic valve replacement.</AbstractText> |
19,878 | Prehospital intravenous access for survival from out-of-hospital cardiac arrest: propensity score matched analyses from a population-based cohort study in Osaka, Japan. | Prehospital intravenous access is a common intervention for patients with out-of-hospital cardiac arrest (OHCA). We aimed to assess the effectiveness of prehospital intravenous access and subsequent epinephrine administration on outcomes among OHCA patients.</AbstractText>We conducted a prospective cohort study of patients with OHCA from non-traumatic causes aged ≥18 years in Osaka, Japan from January 2005 through December 2012. The primary outcome was 1-month survival with favourable neurological outcome defined as a cerebral performance category of 1 or 2. The association between intravenous line placement and survival with favourable neurological outcome was evaluated by logistic regression, after propensity score matching for the intravenous access attempt stratified by initial documented rhythm of ventricular fibrillation (VF) or non-VF. The contribution of epinephrine administration to the outcome was also explored.</AbstractText>Among OHCA patients during the study period, 3208 VF patients and 38 175 non-VF patients were included in our analysis. Intravenous access attempt was negatively associated with 1-month survival with a favourable neurological outcome in VF group (OR 0.76, 95% CI 0.59 to 0.98), while no association was observed in the non-VF group (OR 1.06, 95% CI 0.84 to 1.34). Epinephrine administration had no positive association in the VF patients (OR 0.75, 95% CI 0.51 to 1.07) and positively associated in the non-VF patients (OR 1.52, 95% CI 1.08 to 2.08) with the favourable neurological outcome.</AbstractText>Intravenous access attempt could be negatively associated with survival with a favourable neurological outcome after OHCA. Subsequent epinephrine administration might be effective for non-VF OHCAs.</AbstractText>© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.</CopyrightInformation> |
19,879 | Right Heart Dysfunction in Heart Failure With Preserved Ejection Fraction: The Impact of Atrial Fibrillation. | Right ventricular (RV) dysfunction and atrial fibrillation (AF) frequently coexist in heart failure with preserved ejection fraction (HFpEF). The mechanisms underlying the association between AF and RV dysfunction are incompletely understood.</AbstractText>We identified 102 patients. RV function was assessed with the use of multiple echocardiographic parameters, and dysfunction was present if ≥2 parameters were below the recommended cutoffs. RV function, right atrial (RA) reservoir strain, and RA emptying fraction were compared between AF and sinus rhythm. We included 91 patients with sufficient echocardiographic quality: 45 (50%) had no history of AF, 14 (15%) had earlier AF while in sinus rhythm, and 32 (35%) had current AF. The prevalence of RV dysfunction varied across subgroups (never AF, earlier AF, and current AF: 20%, 43% and 63%, respectively; P = .001). AF was associated with RV dysfunction (odds ratio [OR] 4.70 [95% confidence interval [CI] 1.82-12.1]; P = .001) independently from pulmonary pressures. In patients in sinus rhythm with earlier AF, RA emptying fraction was lower compared with patients without AF history (41 vs 60%; P = .002). Earlier AF was also associated with reduced RA reservoir strain (OR 4.57 [95% CI 1.05-19.9]; P = .04) independently from RV end-diastolic pressure.</AbstractText>Atrial fibrillation is strongly related to reduced RV and RA function in HFpEF independently from pulmonary pressures.</AbstractText>Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
19,880 | A 68-year-old with cranial nerve neuropathies and a troponin rise. | In this case study, we summarise the inpatient investigations and management of a 68-year-old woman with Takotsubo cardiomyopathy secondary to a Varicella zoster encephalitis and the difficulties inherent with making this diagnosis. She presented with evolving cranial nerve neuropathies, which started with a vagal nerve mononeuritis and eventually included left-sided sensorineural hearing loss and a facial nerve palsy. These symptoms were concomitant with a variety of cardiac abnormalities, including fast atrial fibrillation and electrocardiographic changes. We summarise some of the current understanding of Takotsubo cardiomyopathy and the criteria for its diagnosis. Although left ventricular apical ballooning has been described in association with severe infections and states of high stress, we have not seen it reported in association with a Varicella zoster encephalitis. |
19,881 | Control of electrical turbulence by periodic excitation of cardiac tissue. | Electrical turbulence in cardiac tissue is associated with arrhythmias such as life-threatening ventricular fibrillation. Recent experimental studies have shown that a sequence of low-energy electrical far-field pulses is able to terminate fibrillation more gently than a single high-energy pulse which causes severe side effects. During this low-energy antifibrillation pacing (LEAP), only tissue near sufficiently large conduction heterogeneities, such as large coronary arteries, is activated. In order to optimize LEAP, we performed extensive simulations of cardiac tissue perforated by blood vessels, employing two alternative cellular models that exhibit electrical turbulence at a similar length scale. Moreover, the scale of blood vessels in our two-dimensional simulations was chosen such that the threshold for single pulse defibrillation matches experimental values. For each of the 100 initial conditions, we tested different electrical field strengths, pulse shapes, numbers of pulses, and periods between the pulses. LEAP is successful for both models, albeit with substantial differences. One model exhibits a spectrum of chaotic activity featuring a narrow peak around a dominant frequency. In this case, the optimal period between low-energy pulses matches this frequency and LEAP greatly reduces the required energy for successful defibrillation. For pulses with larger energies, the system is perturbed such that underdrive pacing becomes advantageous. The spectrum of the second model features a broader peak, resulting in a less pronounced optimal pacing period and a decreased energy reduction. In both cases, pacing with five or six pulses which are separated by the dominant period maximizes the energy reduction. |
19,882 | Association of initial recorded rhythm and underlying cardiac disease in sudden cardiac arrest. | Asystole (ASY) and pulseless electrical activity (PEA) are increasing and ventricular fibrillation (VF) or ventricular tachycardia (VT) declining as presenting rhythms of sudden cardiac arrest (SCA). Since there is limited information on possible differences in the etiology of underlying structural heart disease, we analyzed the clinical and/or autopsy findings of victims with ASY, PEA or VT/VF.</AbstractText>All SCA cases with recorded ASY, PEA or VT/VF occurring after onset of witnessed collapse were analyzed by the emergency personnel between the years 2007-2012 within the Oulu University Hospital area. Underlying structural heart disease was diagnosed by medico-legal autopsy or by clinical investigation (echocardiography, angiography). Of a total number of 659 subjects with a documented rhythm at the time of SCA, 300 were determined to be due to cardiac disease at autopsy or as a result of clinical investigation. Delay was less than 30min from collapse to rhythm recording in 274 subjects (mean age 65±14 yrs; 214 males, 78.1%).</AbstractText>The presenting rhythm was ASY in 87 (31.8%) PEA in 38 (13.9%) and VT/VF in 149 subjects (54.4%). There was no significant difference in the delay from the onset of collapse to the rhythm recording between ASY (11±8min) and VT/VF (9±6min, p=0.06) or PEA (6±8min) and VT/VF (p=0.334). The majority of SCA subjects had an ischemic cause for the event (n=216, 78.8%). Non-ischemic cause for SCA was associated with non-shockable rhythm (Non-ischemic: ASY 46.6% PEA 17.2% VT/VF 36.2% v. Ischemic: ASY 27.8% PEA 13.0% VT/VF 59.3%) even when adjusted for gender, age and delay from collapse to rhythm recording (ASY/PEA v. VT/VF, OR 3.2 95%CI: 1.67-6.50, p=0.001).</AbstractText>Asystole and PEA are a more common presenting rhythm than VT/VF at the time of SCA in non-ischemic cardiac disease. The decreasing trend of ischemic heart disease as a cause of SCA may partly explain the increasing trend of ASY/PEA.</AbstractText>Copyright © 2017 Elsevier B.V. All rights reserved.</CopyrightInformation> |
19,883 | Monocentric experience of leadless pacing with focus on challenging cases for conventional pacemaker. | Leadless cardiac pacemaker has been developed to reduce complications related to cardiac pacing and is considered as an alternative to conventional pacemaker although safety and efficacy data in clinical practice are limited. The purpose of this study was to investigate the safety and efficacy profile of Micra Transcatheter Pacing System (TPS) used in daily clinical activity with a focus on challenging cases for conventional pacing.</AbstractText>A total of 66 patients (46 men, 79.1 ± 9.7 years) having a Class I or II indication for ventricular pacing underwent a Micra TPS implant procedure. All patients were enrolled in a prospective registry. Follow-up visits were scheduled at discharge and after 1, 3, 6 and 12 months.</AbstractText>Primary indication for pacing was third degree atrioventricular block (30.3%), sinus node dysfunction (21.2%) or permanent atrial fibrillation with bradycardia (45.5%). The device was successfully implanted in 65 patients (98.5%). During follow-up of 10.4 ± 6.1 months (range 1-23 months), electrical measurements remained stable. Mean pacing capture threshold, pacing impedance and R-wave sensing were respectively 0.57 ± 0.32 V, 580 ± 103 Ohms, 10.62 ± 4.36 mV at the last follow-up. One major (loss of function) and three minor adverse events occurred. Pericardial effusion, dislodgement, device related infection or pacemaker syndrome were not observed. Micra TPS implantation was straightforward for patients with congenital or acquired cardiac and/or vascular abnormalities, previous tricuspid surgery and after heart transplantation.</AbstractText>Our experience confirms that implantation of Micra is safe and efficient in a real world population including patients who present a challenging condition for conventional pacing.</AbstractText> |
19,884 | Phenotyping of Sleep-Disordered Breathing in Patients With Chronic Heart Failure With Reduced Ejection Fraction-the SchlaHF Registry. | Different sleep-disordered breathing (SDB) phenotypes, including coexisting obstructive and central sleep apnea (OSA-CSA), have not yet been characterized in a large sample of patients with heart failure and reduced ejection fraction (HFrEF) receiving guideline-based therapies. Therefore, the aim of the present study was to determine the proportion of OSA, CSA, and OSA-CSA, as well as periodic breathing, in HFrEF patients with SDB.</AbstractText>The German SchlaHF registry enrolled patients with HFrEF receiving guideline-based therapies, who underwent portable SDB monitoring. Polysomnography (n=2365) was performed in patients with suspected SDB. Type of SDB (OSA, CSA, or OSA-CSA), the occurrence of periodic breathing (proportion of Cheyne-Stokes respiration ≥20%), and blood gases were determined in 1557 HFrEF patients with confirmed SDB. OSA, OSA-CSA, and CSA were found in 29%, 40%, and 31% of patients, respectively; 41% showed periodic breathing. Characteristics differed significantly among SDB groups and in those with versus without periodic breathing. There was a relationship between greater proportions of CSA and the presence of periodic breathing. Risk factors for having CSA rather than OSA were male sex, older age, presence of atrial fibrillation, lower ejection fraction, and lower awake carbon dioxide pressure (pco2</sub>). Periodic breathing was more likely in men, patients with atrial fibrillation, older patients, and as left ventricular ejection fraction and awake pco2</sub> decreased, and less likely as body mass index increased and minimum oxygen saturation decreased.</AbstractText>SchlaHF data show that there is wide interindividual variability in the SDB phenotype of HFrEF patients, suggesting that individualized management is appropriate.</AbstractText>URL: https://www.clinicaltrials.gov/. Unique identifier: NCT01500759.</AbstractText>© 2017 The Authors and ResMed Germany Inc. Published on behalf of the American Heart Association, Inc., by Wiley.</CopyrightInformation> |
19,885 | Multi-modality imaging evaluation of recurrent Tako-tsubo syndrome in a patient with coronary artery fibromuscular dysplasia. | Integrated bedside and sophisticated cardiac imaging techniques help characterize the discrepancy between myocardial injury and mechanic dysfunction in acute myocardial infarction.</AbstractText>A 57 year-old woman presented with sudden onset chest pain and ventricular fibrillation after hearing of her brother's death. The electrocardiography indicated "anterior wall ST segment elevation myocardial infarction". Coronary angiography ruled out obstructive lesion in the major coronary arteries, but revealed fibromuscular dysplasia of the distal left anterior descending artery. The ventriculography showed remarkable ventricular dilation, which affected much broader myocardium than the culprit vessel supplied. In a subsequent cardiac magnetic resonance study, delayed contrast (gadolinium) image revealed a focal left ventricular (LV) apical infarction. Her LV systolic function normalized within 1 week, except for a residual apical hypokinesis. She developed recurrent chest pain and LV dilation when she was laid off 9 months later. After supportive therapy, her symptoms improved and LV dysfunction normalized again.</AbstractText>"Tako-tsubo" syndrome can occur recurrently in the heart with pre-existing localized myocardial infarction. Its molecular mechanism and clinical significance warrants further investigation.</AbstractText> |
19,886 | Atrioventricular dromotropathy: evidence for a distinctive entity in heart failure with prolonged PR interval? | Heart failure (HF) is often accompanied by atrioventricular (AV) conduction disturbance, represented by prolongation of the PR interval on the electrocardiogram. Studies suggest that PR prolongation exists in at least 10% of HF patients, and it seems more prevalent in the presence of prolonged QRS duration. A prolonged PR interval may result in elevated left ventricular (LV) end-diastolic pressure, diastolic mitral regurgitation, and reduced LV pump function. This seems especially the case in patients with heart disease, in whom it is associated with an increased risk for atrial fibrillation, advanced AV heart block, HF, and death. These findings point towards the importance of proper AV coupling in HF patients. A few studies, strongly differing in design, suggest that restoration of AV coupling in patients with PR prolongation by pacing improves cardiac function and clinical outcomes. These observations argue for AV-dromotropathy as a potential target for pacing therapy, but other studies show inconsistent results. Given its potential clinical implications, restoration of AV coupling by pacing warrants further investigation. Additional possible future research goals include assessing different techniques to measure compromised AV coupling, determine the best site(s) of ventricular pacing, and assess a potential influence of diastolic mitral regurgitation in the efficacy of such therapy. |
19,887 | Appropriate implantable cardioverter-defibrillator interventions in cardiac resynchronization therapy-defibrillator (CRT-D) patients undergoing device replacement: time to downgrade from CRT-D to CRT-pacemaker? Insights from real-world clinical practice in the DECODE CRT-D analysis. | Ventricular tachycardia (VT)/ventricular fibrillation (VF) occurrence after cardiac resynchronization therapy-defibrillator (CRT-D) replacement is unknown; hence, there is no practical guideline to recommend either CRT-D or CRT-pacemaker at the time of device replacement. We observed the 1-year VT/VF occurrence after CRT-D replacement in a subanalysis of the Detect Long-term Complications after ICD Replacement (DECODE) registry.</AbstractText>A total of 332 consecutive patients who had undergone CRT-D replacement from 2013 to 2015 were enrolled in 36 Italian centres. The primary endpoint was the number of patients with any appropriate implantable cardioverter-defibrillator (ICD) interventions during 12-month follow-up. The secondary endpoint comprised death from any cause and appropriate ICD interventions. At replacement, 214 (64.5%) patients had a left ventricular ejection fraction ≤ 35% and 138 (41.6%) patients had a secondary prevention indication for ICD. Seventy (21.1%) patients had no longer indication to ICD therapy. During a median follow-up period of 406.5 (362-533) days, VT/VF requiring therapy delivery occurred in 57 (17%) patients, specifically in 7% of those who no longer had an ICD indication. On multivariate analysis, number of criteria for ICD replacement independently predicted appropriate ICD intervention during follow-up [hazard ratio (HR) = 1.62, 95% confidence interval (CI) 1.07-2.46; log-rank P = 0.02]. The combined endpoint of death from any cause or appropriate ICD therapy occurred in 76 (23%) patients. Only NYHA class remained associated with this combined endpoint (HR = 1.97, 95% CI 1.23-3.14; P = 0.005).</AbstractText>The DECODE registry showed the 'real-world' experience of CRT-D recipients approaching device replacement, in which 7% of patients who no longer had an indication for ICD therapy experienced appropriate ICD interventions.</AbstractText> |
19,888 | Metabolomics profiling reveals different patterns in an animal model of asphyxial and dysrhythmic cardiac arrest. | Cardiac arrest (CA) is not a uniform condition and its pathophysiology strongly depends on its cause. In this work we have used a metabolomics approach to study the dynamic metabolic changes occurring in the plasma samples of a swine model following two different causes of CA, namely asphyxia (ACA) and ventricular fibrillation (VFCA). Plasma samples were collected at baseline and every minute during the experimental phases. In order to identify the metabolomics profiles characterizing the two pathological entities, all samples were analysed by <sup>1</sup>H NMR spectroscopy and LC-MS/MS spectrometry.The metabolomics fingerprints of ACA and VFCA significantly differed during the peri-arrest period and the resuscitation phase. Major alterations were observed in plasma concentrations of metabolites related to tricarboxylic acid (TCA) cycle, urea cycle, and anaplerotic replenishing of TCA. ACA animals showed significant metabolic disturbances during the asphyxial and CA phases, while for VFCA animals this phenomenon resulted shifted at the resuscitation phase. Interestingly, starting from the asphyxial phase, the ACA animals were stratified in two groups based on their metabolomics profiles that resulted to be correlated with the clinical outcome. Succinate overproduction was observed in the animals with the worse outcome, suggesting a potential prognostic role for this metabolite. |
19,889 | Association between left atrial phasic conduit function and early atrial fibrillation recurrence in patients undergoing electrical cardioversion. | Diastolic dysfunction promotes atrial fibrillation (AF) inducing left atrial (LA) remodeling, with chamber dilation and fibrosis. Predominance of LA phasic conduit (LAC) function should reflect not only chamber alterations but also underlying left ventricular (LV) filling impairment. Thus, LAC was tested as possible predictor of early AF relapse after electrical cardioversion (EC).</AbstractText>96 consecutive patients, who underwent EC for persistent non-valvular AF, were prospectively enrolled. Immediately after successful EC (3 h ± 15 min), an echocardiographic apical four-chamber view was acquired with transmitral velocities, annular tissue Doppler and simultaneous LV and LA three-dimensional full-volume datasets. Then, from LA-LV volumetric curves we computed LAC as: [(LV maximum - LV minimum) - (LA maximum - LA minimum) volume], expressed as % LV stroke volume. LA pump, immediately post-EC, was assumed and verified as being negligible. Sinus rhythm persistence at 1 month was checked with ECG-Holter monitoring.</AbstractText>At 1 month 62 patients were in sinus rhythm and 34 in AF. AF patients presented pre-EC higher E/é values (p = 0.012), no major LA volume differences (p = NS), but a stiffer LV cavity (p = 0.012) for a comparable LV capacitance (p = 0.461). Conduit contributed more (p < 0.001) to LV stroke volume in AF subpopulation. Multiple regression revealed LAC as the most significant AF predictor (p = 0.013), even after correction for biometric characteristics and pharmacotherapy (p = 0.008).</AbstractText>Our data suggest that LAC larger contribution to LV filling soon after EC reflects LA-LV stiffening, which skews atrioventricular interaction leading to AF perpetuation and makes conduit dominance a powerful predictor of early AF recurrence.</AbstractText> |
19,890 | A New Class III Antiarrhythmic Drug Niferidil Prolongs Action Potentials in Guinea Pig Atrial Myocardium via Inhibition of Rapid Delayed Rectifier. | A new class III antiarrhythmic drug niferidil (RG-2) has been introduced as a highly effective therapy for cases of persistent atrial fibrillation, but ionic mechanisms of its action are poorly understood. In the present study, the effects of niferidil on action potential (AP) waveform and potassium currents responsible for AP repolarization were investigated in guinea pig atrial myocardium.</AbstractText>APs were recorded with sharp glass microelectrodes in multicellular atrial preparations. Whole-cell patch-clamp technique was used to measure K+</sup> currents in isolated myocytes.</AbstractText>In multicellular atrial preparations, 10-8</sup> M niferidil effectively prolonged APs by 15.2 ± 2.8% at 90% repolarization level. However, even the highest tested concentrations, 10-6</sup> M and 10-5</sup> M failed to prolong APs more than 32.5% of control duration. The estimated concentration of niferedil for half-maximal AP prolongation was 1.13 × 10-8</sup> M. Among the potassium currents responsible for AP repolarization phase, I K1</sub> was found to be almost insensitive to niferidil. However, another inward rectifier, I KACh</sub>, was effectively suppressed by micromolar concentrations of niferidil with IC50</sub> = 9.2 × 10-6</sup> M. I KATP</sub> was much less sensitive to the drug with IC50</sub> = 2.26 × 10-4</sup> M. The slow component of delayed rectifier, I Ks</sub>, also demonstrated low sensitivity to niferidil-the highest used concentration, 10-4</sup> M, decreased peak I Ks</sub> density to 46.2 ± 5.5% of control. Unlike I Ks</sub>, the rapid component of delayed rectifier, I Kr</sub>, appeared to be extremely sensitive to niferidil. The IC50</sub> was 1.26 × 10-9</sup> M. I Kr</sub> measured in ventricular myocytes was found to be less sensitive to niferidil with IC50</sub> = 3.82 × 10-8</sup> M.</AbstractText>Niferidil prolongs APs in guinea pig atrial myocardium via inhibition of I Kr</sub>.</AbstractText> |
19,891 | Off label use of direct oral anticoagulants for left ventricular thrombus. Is it appropriate? | A 57 year old gentleman with a history of non-ischemic cardiomyopathy and paroxysmal atrial fibrillation presented with worsening lower extremity edema and dyspnea on exertion. He had been compliant with his medications including rivaroxaban (Xarelto) for atrial fibrillation that he takes with the evening meal daily. His echocardiogram showed an ejection fraction of 10-15% and a new left ventricle (LV) apical thrombus. During his hospital stay, he developed right sided weakness. Magnetic Resonance Imaging showed a subacute infarct involving the left parietal lobe. The decision was made to discontinue rivaroxaban and initiate heparin infusion instead. Meanwhile, the patient's neurological symptoms were closely monitored. The patient was then transitioned to warfarin. He was eventually transferred to the rehabilitation floor with minimal residual neurologic weakness. Left ventricular thrombus is an important complication in the setting of systolic dysfunction. The combination of blood stasis, endothelial injury and hypercoagulability, is a prerequisite for in-vivo thrombus formation. The slow onset of action and reversal, need for frequent monitoring, narrow therapeutic range, dietary restrictions, and multiple drug interactions limit the use of vitamin K antagonists. Direct-acting oral anticoagulants (DOACs) do not have these limitations and may also reduce the risk of hemorrhagic stroke. Our patient developed an LV thrombus while on uninterrupted DOAC therapy. |
19,892 | Wearable cardioverter defibrillators for the prevention of sudden cardiac arrest: a health technology assessment and patient focus group study. | To summarize the evidence on clinical effectiveness and safety of wearable cardioverter defibrillator (WCD) therapy for primary and secondary prevention of sudden cardiac arrest in patients at risk.</AbstractText>We performed a systematic literature search in databases including MEDLINE via OVID, Embase, the Cochrane Library, and CRD (DARE, NHS-EED, HTA). The evidence obtained was summarized according to GRADE methodology. A health technology assessment (HTA) was conducted using the HTA Core Model®</sup> for rapid relative effectiveness assessment. Primary outcomes for the clinical effectiveness domain were all-cause and disease-specific mortality. Outcomes for the safety domain were adverse events (AEs) and serious adverse events (SAEs). A focus group with cardiac disease patients was conducted to evaluate ethical, organizational, patient, social, and legal aspects of the WCD use.</AbstractText>No randomized- or non-randomized controlled trials were identified. Non-comparative studies (n=5) reported AEs including skin rash/itching (6%), false alarms (14%), and palpitations/light-headedness/fainting (9%) and discontinuation due to comfort/lifestyle issues (16-22%), and SAEs including inappropriate shocks (0-2%), unsuccessful shocks (0-0.7%), and death (0-0.3%). The focus group results reported that experiencing a sense of security is crucial to patients and that the WCD is not considered an option for weeks or even months due to expected restrictions in living a "normal" life.</AbstractText>The WCD appears to be relatively safe for short-to-medium term, but the quality of existing evidence is very low. AEs and SAEs need to be more appropriately reported in order to further evaluate the safety of the device. High-quality comparative evidence and well-described disease groups are required to assess the effectiveness of the WCD and to determine which patient groups may benefit most from the intervention.</AbstractText> |
19,893 | Clinical Outcomes After Ablation of the AV Junction in Patients With Atrial Fibrillation: Impact of Cardiac Resynchronization Therapy. | Patients with atrial fibrillation (AF) often undergo AV junction ablation (AVJA) and pacemaker implantation. Right ventricular (RV) pacing contributes to increased risk of heart failure (HF), which may be mitigated by biventricular pacing. We sought to determine the impact of AVJA concurrent with RV versus biventricular pacemaker implantation on AF and HF hospitalizations.</AbstractText>The MarketScan Commercial and Medicare Supplemental claims database was used to select 18- to 100-year-old patients with AF with pacemaker implantation. Patients were divided into those with an RV and a biventricular pacemaker and further into those who did (AVJA+</sup>) or did not undergo concurrent ablation. Separately, the AVJA+</sup> group was divided into those receiving RV versus biventricular pacemakers. AF and HF hospitalization rates were compared between groups after matching on demographics, comorbidities, and baseline hospitalization rates. The study included 24 361 patients, with RV (n=23 377) or biventricular (n=984) pacemakers; 1611 patients underwent AVJA. AVJA+</sup> was associated with reduced AF hospitalization risk (RV hazard ratio [HR], 0.31; P</i><0.001; biventricular HR, 0.20; P</i>=0.003) compared with no AVJA. However, HF hospitalization risk was increased for RV (HR, 1.63; P</i>=0.001), but not biventricular (HR, 0.98; P</i>=0.942), pacemakers. In AVJA+</sup> patients, biventricular pacing was associated with reduced risk of HF hospitalization versus RV pacing (HR, 0.62; P</i>=0.017).</AbstractText>In a large cohort of patients with AF, AVJA+</sup> significantly reduced AF hospitalizations, irrespective of whether an RV or a biventricular pacemaker was implanted. However, AVJA was associated with a marked HF hospitalization increase in patients with an RV pacemaker, which was ameliorated with biventricular pacing.</AbstractText>© 2017 The Authors and Abbott. Published on behalf of the American Heart Association, Inc., by Wiley.</CopyrightInformation> |
19,894 | Antihypertensive Treatment With β-Blockade in Patients With Asymptomatic Aortic Stenosis and Association With Cardiovascular Events. | Patients with aortic stenosis (AS) often have concomitant hypertension. Antihypertensive treatment with a β-blocker (Bbl) is frequently avoided because of fear of depression of left ventricular function. However, it remains unclear whether antihypertensive treatment with a Bbl is associated with increased risk of cardiovascular events in patients with asymptomatic mild to moderate AS.</AbstractText>We did a post hoc analysis of 1873 asymptomatic patients with mild to moderate AS and preserved left ventricular ejection fraction in the SEAS (Simvastatin and Ezetimibe in Aortic Stenosis) study. Propensity-matched Cox regression and competing risk analyses were used to assess risk ratios for all-cause mortality, sudden cardiac death, and cardiovascular death. A total of 932 (50%) patients received Bbl at baseline. During a median follow-up of 4.3±0.9 years, 545 underwent aortic valve replacement, and 205 died; of those, 101 were cardiovascular deaths, including 40 sudden cardiovascular deaths. In adjusted analyses, Bbl use was associated with lower risk of all-cause mortality (hazard ratio 0.5, 95% confidence interval 0.3-0.7, P</i><0.001), cardiovascular death (hazard ratio 0.4, 95% confidence interval 0.2-0.7, P</i><0.001), and sudden cardiac death (hazard ratio 0.2, 95% confidence interval 0.1-0.6, P</i>=0.004). This was confirmed in competing risk analyses (all P</i><0.004). No interaction was detected with AS severity (all P</i>>0.1).</AbstractText>In post hoc analyses Bbl therapy did not increase the risk of all-cause mortality, sudden cardiac death, or cardiovascular death in patients with asymptomatic mild to moderate AS. A prospective study may be warranted to determine if Bbl therapy is in fact beneficial.</AbstractText>URL: http://www.clinicaltrials.gov. Unique identifier: NCT00092677.</AbstractText>© 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.</CopyrightInformation> |
19,895 | Unique genetic background and outcome of non-Caucasian Japanese probands with arrhythmogenic right ventricular dysplasia/cardiomyopathy. | Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) is an inherited cardiomyopathy mainly caused by desmosomal gene mutation. More than half of Caucasian probands have desmosomal mutations, which lead to earlier onset of ventricular arrhythmias. Among non-Caucasians, the genetic background of ARVD/C probands and its prognostic impact remain unclear.</AbstractText>We genotyped 99 unrelated Japanese ARVD/C probands for plakophilin 2 (PKP2), desmoglein 2 (DSG2), desmoplakin (DSP), and desmocollin 2 (DSC2) between 2005 and 2014. Seventy-five probands who fulfilled "definite" category according to the 2010 Task Force Criteria (TFC) were enrolled and followed up for 6.4 years. Sixty-four percent of probands had desmosomal mutations; DSG2 was predominant (48% of mutations) followed by PKP2 (38%). DSG2 mutations were almost missense, whereas over 90% of PKP2 mutations were truncating mutations. Lethal ventricular arrhythmias (VAs, sustained ventricular tachycardia/fibrillation) occurred in 57% of probands as the first manifestation and 71% at the end of follow-up. Five died during follow-up. Truncating mutation carriers exhibited earlier lethal VAs onset compared to missense mutation carriers or mutation negatives (age at onset 35 ± 12, 49 ± 16, and 50 ± 19 years, respectively, P < 0.05 in each). Cox proportional hazard analysis revealed for the first time that, compared to mutation negatives, truncating mutation carriers had higher risk for lethal VAs, and especially for onset by their 40s, in an age-dependent manner (RR = 4.6, P < 0.01 by their 40s; RR = 2.9, P = 0.01 by their 50s).</AbstractText>The genetic background of Japanese ARVD/C probands is distinct from that of Caucasian probands, leading to distinct prognosis. The most affected gene mutations in Japanese probands were missense mutations in DSG2 leading to modest outcome, whereas PKP2 truncating mutations were the second most and might be a strong marker for lethal VAs in non-Caucasian Japanese ARVD/C probands.</AbstractText>© 2017 The Authors. Molecular Genetics & Genomic Medicine published by Wiley Periodicals, Inc.</CopyrightInformation> |
19,896 | Compound heterozygous CASQ2 mutations and long-term course of catecholaminergic polymorphic ventricular tachycardia. | Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a potentially lethal inherited cardiac disorder characterized by episodic ventricular tachycardia during adrenergic stimulation. It is associated with significant morbidity and mortality. Knowledge of the underlying genetic cause, pathogenesis, and the natural history of the disease remains incomplete. Approximately 50% of CPVT cases are caused by dominant mutations in the cardiac ryanodine receptor (RYR2) gene, <5% of cases are accounted for by recessive mutations in cardiac calsequestrin (CASQ2) or Triadin (TRDN).</AbstractText>We report a family with two CASQ2 gene mutations. A research-based next-generation sequencing (NGS) initiative was used in a patient with a severe CPVT phenotype and her clinically unaffected son. Reverse transcription polymerase chain reaction (RT-PCR) from platelet RNA was used to assess the consequences of predicted splice variants.</AbstractText>NGS revealed that the proband carried a novel c.199C>T (p.Gln67*) mutation and a previously reported splice site mutation c.532+1G>A in CASQ2. Her son is a heterozygous carrier of the c.199C>T (p.Gln67*) mutation alone and the proband was compound heterozygous at CASQ2. RNA analysis demonstrated that the splice site mutation results in the retention of intron 3 with no full-length CASQ2 mRNA.</AbstractText>This study describes a novel CPVT genotype and further characterizes the effect of a previously reported CASQ2 splice site mutation. The long-term follow-up of 23 years since first symptom provides additional insight into the natural history of CASQ2-associated CPVT.</AbstractText>© 2017 The Authors. Molecular Genetics & Genomic Medicine published by Wiley Periodicals, Inc.</CopyrightInformation> |
19,897 | Predicting Survival in Patients With Heart Failure With an Implantable Cardioverter Defibrillator: The Heart Failure Meta-Score. | Prognostic evaluation in heart failure (HF) is important to predict future events and decide timely management. Many HF patients are treated with the use of an implantable cardioverter-defibrillator (ICD). This study aimed to validate a meta-analytically derived prognostic score to predict survival in ICD-HF patients.</AbstractText>The HF Meta-score includes 14 independent mortality predictors identified in a meta-analysis, including age, sex, ethnicity, diabetes, chronic obstructive pulmonary disease, peripheral vascular disease, atrial fibrillation, ischemic cardiomyopathy, history of HF admission, New York Heart Association functional class, left ventricular ejection fraction, renal function, QRS duration, secondary prevention indication, and ICD shocks. The HF Meta-score performance was evaluated in comparison with the Seattle Heart Failure Model (SHFM) and the SHOCKED predictors in a cohort of 9860 ambulatory ICD patients from the Ontario provincial database for 2007-2011. During 3-year follow-up, 1816 patients died. The HF Meta-score showed excellent calibration, very good discrimination (c-statistic 0.74) and enhanced risk classification compared with the SHOCKED predictors, with better reclassifying in 19% and 56% of patients for 1- and 3-year survival, respectively. HF Meta-score performance was similar to the SHFM.</AbstractText>The HF Meta-score is an evidence-based derived model that provides an accurate prognosis assessment in HF patients with ICDs. Its development strategy permits further incorporation of new predictors when evidence becomes available.</AbstractText>Copyright © 2017 Elsevier Inc. All rights reserved.</CopyrightInformation> |
19,898 | Risk of Cardiac Events Associated With Antidepressant Therapy in Patients With Long QT Syndrome. | Patients with long QT syndrome (LQTS) are at a high risk of cardiac events. Many patients with LQTS are treated with antidepressant drugs (ADs). We investigated the LQTS genotype-specific risk of recurrent cardiac arrhythmic events (CAEs) associated with AD therapy. The study included 59 LQT1 and 72 LQT2 patients from the Rochester-based LQTS Registry with corrected QT (QT<sub>c</sub>) prolongation and a history of AD therapy. Using multivariate Anderson-Gill models, we estimated the LQTS genotype-specific risk of recurrent CAEs (ventricular tachyarrhythmias, aborted cardiac arrest, or sudden cardiac death) associated with time-dependent ADs. Specifically, we examined the risk associated with all ADs, selective serotonin reuptake inhibitor (SSRI), and ADs classified on the CredibleMeds list (www.CredibleMeds.org) as "Conditional" or "Known risk of Torsades de pointes (TdP)." After adjusting for baseline QT<sub>c</sub> duration, sex, and time-dependent beta-blocker usage, there was an increased risk of recurrent CAEs associated with ADs in LQT1 patients (hazard ratio = 3.67, 95% confidence interval 1.98-6.82, p < 0.001) but not in LQT2 patients (hazard ratio = 0.89, 95% confidence interval 0.49-1.64, p = 0.716; LQT1 vs LQT2 interaction, p < 0.001). Similarly, LQT1 patients who were on SSRIs or ADs with "Known risk of TdP" had a higher risk of recurrent CAEs than those patients off all ADs, whereas there was no association in LQT2 patients. ADs with "Conditional risk of TdP" were not associated with the risk of recurrent CAEs in any of the groups. In conclusion, the risk of recurrent CAEs associated with time-dependent ADs is higher in LQT1 patients but not in LQT2 patients. Results suggest a LQTS genotype-specific effect of ADs on the risk of arrhythmic events. |
19,899 | Atrial electrical abnormality in patients with Brugada syndrome assessed by signal-averaged electrocardiography. | Ventricular fibrillation and atrial fibrillation are well-known arrhythmias in patients with Brugada syndrome. This study evaluated the characteristics of the atrial arrhythmogenic substrate using the signal-averaged electrogram (SAECG) in patients with Brugada syndrome.</AbstractText>SAECGs were performed during normal sinus rhythm in 23 normal volunteers (control group), 21 patients with paroxysmal atrial fibrillation (PAF; PAF group), and 21 with Brugada syndrome (Brugada group).</AbstractText>The filtered P wave duration (fPd) in the control, Brugada, and PAF groups was 113.9±12.9ms, 125.3±15.0ms, and 137.1±16.3ms, respectively. The fPd in the PAF group was significantly longer compared to that in the control and Brugada groups (p<0.05). The fPd in the Brugada group was significantly longer than that in the control group (p<0.05) and significantly shorter than that in the PAF group (p<0.05).</AbstractText>Patients with Brugada syndrome had abnormal P waves on the SAECG. The abnormal P waves on the SAECG in Brugada syndrome patients may have intermediate characteristics between control and PAF patients.</AbstractText>Copyright © 2017 Cardiological Society of India. Published by Elsevier B.V. All rights reserved.</CopyrightInformation> |
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