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13,800 | Mitraclip therapy and surgical mitral repair in patients with moderate to severe left ventricular failure causing functional mitral regurgitation: a single-centre experience. | Surgical mitral repair is the conventional treatment for severe symptomatic functional mitral regurgitation (FMR). Mitraclip therapy is an emerging option for selected high-risk patients with FMR. The aim of this study was to report the outcomes of patients who underwent a surgical mitral repair and Mitraclip therapy for FMR in our experience.</AbstractText>From March 2000 and April 2011, 143 patients with FMR were treated in our institution: 91 patients (63.6%) underwent surgical mitral repair (49% ischaemic; 51% idiopathic) and 52 (36.4%) underwent Mitraclip implantation (71% ischaemic; 29% idiopathic). Associated procedures in the surgical group were myocardial revascularization in 35%, tricuspid repair in 25% and atrial fibrillation ablation in 26%. Follow-up was 100% complete (median 18; 6.4-45 months for surgery and 8.5; 4-12 months for Mitraclip).</AbstractText>Mitraclip patients were older (P = 0.04), had higher log EuroSCORE (P < 0.0001), lower LVEF (P = 0.006) and higher left ventricular diameter (P = 0.01 for left ventricular end-diastolic diameter and P = 0.05 for left ventricular end-systolic diameter). Major postoperative infection or sepsis occurrence was higher in the surgical group (16.3 vs. 3.8%; P = 0.01), while no differences were observed in terms of acute renal failure, cardiogenic shock, cerebrovascular accident and acute myocardial infarction. Length-of-stay was 11 days (IQR: 7-19 days) for surgery and 5 days (IQR: 4-9 days) for MitraClip (P < 0.0001). In-hospital mortality was 6.6% for surgery (6/91) and 0% for Mitraclip (P = 0.01). Surgery was identified as a predictor of in-hospital death (OR: 2.61; P = 0.01). Residual MR ≥ 3+ at discharge was 0% for surgery and 9.6% for Mitraclip (P = 0.002). At follow-up, actuarial survival at 1 year was 88.9 ± 3.5% for surgery and 87.5 ± 7% for Mitraclip (P = 0.6). Actuarial freedom from MR ≥ 3+ at 1 year was 79.1 ± 8% for MitraClip and 94 ± 2% for surgery (P = 0.01). At last follow-up, most of the survivors were in NYHA class I-II.</AbstractText>Mitraclip therapy is a safe therapeutic option in selected high-risk patients with FMR, and it is associated with a lower hospital mortality and shorter length-of-stay compared with surgery, in spite of worse preoperative conditions. Early and 1-year rates of recurrent MR are higher with Mitraclip. Further studies are needed to determine the long-term clinical impact.</AbstractText> |
13,801 | Reliable porcine coronary model of chronic total occlusion using copper wire stents and bioabsorbable levo-polylactic acid polymer. | Chronic total occlusion (CTO) remains a challenge in interventional cardiology. We investigated the feasibility and reliability of copper wire stents and levo-polylactic acid (l-PLA) as a means of CTO induction in a porcine model.</AbstractText>In one group of 20 swine, copper stents were crimped on a 3.0mm angioplasty balloon and inserted into the mid-left anterior descending coronary artery (LAD). In the other group of 20 swine, l-PLA was wrapped on a guidewire and pushed into the distal LAD with a 3.0mm balloon catheter to induce embolization. Of 20 swine which underwent copper stent implantation, 13 died of stent thrombosis. In the remaining 7 swine, total or near total occlusion with collateral circulation was observed at 5 weeks. Of 20 swine which underwent l-PLA embolization, 4 died of ventricular fibrillation during or shortly after the procedure. Serial histopathologic studies showed complete absorption of the polymer with replacement by fibrotic tissue approximately 4 weeks following the polymer implantation.</AbstractText>CTO could be reliably induced in porcine coronary arteries by copper stents and l-PLA. These models may support investigation of new percutaneous devices to facilitate CTO interventions.</AbstractText>Copyright © 2012 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.</CopyrightInformation> |
13,802 | Sudden death. | Sudden death is probably the greatest challenge in modern cardiology. After reviewing its history, we describe the epidemiology of sudden death and its associated diseases. We highlight its physiopathologic aspects, including the factors that act on vulnerable myocardium triggering the final arrhythmia, mainly ventricular fibrillation and, to a lesser extent, bradycardia and sudden death. We emphasize the relevance of acute ischemia, ventricular dysfunction and genetic factors, not only in genetic heart disease, but also as triggers of sudden death in acute and chronic ischemic heart disease. Finally, we describe the best way to identify candidates at risk, discuss how to prevent sudden death, and outline the best approach to managing a patient resuscitated from cardiac arrest. Full English text available from:www.revespcardiol.org. |
13,803 | Heart rate control in patients with chronic atrial fibrillation and heart failure. | The goal of this study was to determine whether aggressive heart rate (HR) control in patients with both chronic atrial fibrillation (AF) and heart failure (HF) is associated with improved outcomes. HR control is one of the mainstays in management of patients with AF. However, rate control can be challenging in patients with HF. This study was designed as an interventional clinical trial, using patients with chronic AF and left ventricular systolic dysfunction with left ventricular ejection fraction ≤40% (n=20) as their own controls. Intervention consisted of increasing doses of metoprolol succinate to achieve target resting HR <70 beats per minute. Clinical data were collected at baseline and after intervention, with paired t test used to evaluate statistically significant change. After 3 months of intervention, average resting HR decreased from 94±14 beats per minute to 85±12 beats per minute. Average metoprolol succinate dose at the end of the study was 121 mg. None of the outcomes improved significantly after the intervention, including exercise tolerance (meters walked on 6-minute walk test 326±83 vs 330±86), quality of life (Minnesota Living With Heart Failure Questionnaire score of 42.5±19 vs 38±21), and brain natriuretic peptide (242±306 pg/mL vs 279±395 pg/mL). Aggressive HR control was difficult in this group of patients with chronic AF and HF due to patient intolerance of increasing doses of β-blockade, and not associated with improved outcomes. Further studies are needed to establish guidelines for target HR in patients with chronic AF who also have significant HF. |
13,804 | Atrial arrhythmia, triggering events and conduction abnormalities in isolated murine RyR2-P2328S hearts. | RyR2 mutations are associated with catecholaminergic polymorphic tachycardia, a condition characterized by ventricular and atrial arrhythmias. The present experiments investigate the atrial electrophysiology of homozygotic murine RyR2-P2328S (RyR2(S/S)) hearts for ectopic triggering events and for conduction abnormalities that might provide a re-entrant substrate.</AbstractText>Electrocardiograph recordings were made from regularly stimulated RyR2(S/S) and wild type (WT) hearts, perfused using a novel modified Langendorff preparation. This permitted the simultaneous use of either floating intracellular microelectrodes to measure action potential (AP) parameters, or a multielectrode array to measure epicardial conduction velocity (CV).</AbstractText>RyR2(S/S) showed frequent sustained tachyarrhythmias, delayed afterdepolarizations and ectopic APs, increased interatrial conduction delays, reduced epicardial CVs and reduced maximum rates of AP depolarization ((dV/dt)(max)), despite similar effective refractory periods, AP durations and AP amplitudes. Effective interatrial CVs and (dV/dt)(max) values of APs following ectopic (S2) stimulation were lower than those of APs following regular stimulation and decreased with shortening S1S2 intervals. However, although RyR2(S/S) atria showed arrhythmias over a wider range of S1S2 intervals, the interatrial CV and (dV/dt)(max) of S2 APs provoking such arrhythmias were similar in RyR2(S/S) and WT.</AbstractText>These results suggest that abnormal intracellular Ca(2+) homoeostasis produces both arrhythmic triggers and a slow-conducting arrhythmic substrate in RyR2(S/S) atria. A similar mechanism might also contribute to arrhythmogenesis in other conditions, associated with diastolic Ca(2+) release, such as atrial fibrillation.</AbstractText>© 2012 The Authors Acta Physiologica © 2012 Scandinavian Physiological Society.</CopyrightInformation> |
13,805 | Hypertrophic cardiomyopathy mimicking acute anterior myocardial infarction associated with sudden cardiac death. | Hypertrophic cardiomyopathy is the most common genetic disease of the heart. We report a rare case of hypertrophic obstructive cardiomyopathy mimicking an acute anterior myocardial infarction associated with sudden cardiac death. The patient presented with acute ST elevation myocardial infarction and significant elevation of cardiac enzymes. Cardiac catheterization showed some atherosclerotic coronary artery disease, without significant stenosis. Echocardiography showed left ventricular hypertrophy with a left ventricular outflow tract obstruction; the pressure gradient at rest was 20 mmHg and became severe with the Valsalva maneuver (100 mmHg). There was no family history of sudden cardiac death. Six days later, the patient suffered a syncope on his way to magnetic resonance imaging. He was successfully resuscitated by ventricular fibrillation. |
13,806 | Ventricular tachycardia in coronary artery disease. | Ventricular arrhythmias are important contributors to morbidity and mortality in patients with coronary artery disease. Ventricular fibrillation accounts for the majority of deaths occurring in the acute phase of ischemia, whereas sustained, monomorphic ventricular tachycardia due to reentry generated in the scar tissue develops most often in the setting of healed myocardial infarction, especially in patients with lower left ventricular ejection fraction. Despite determinant advances in population education and myocardial infarction management, the ventricular tachycardia risk in the overall population with coronary artery disease continues to be a major problem in clinical practice. The initial evaluation of a patient presenting with ventricular tachycardia requires a 12-lead electrocardiogram, which can be helpful to confirm the diagnosis, suggest the presence of potential underlying heart disease, and identify the location of the ventricular tachycardia circuit. An invasive electrophysiologic study is usually crucial to determine the mechanism of the arrhythmia once induced and to provide guidance for ablation. The approach for ventricular tachycardia ablation depends on several factors, including inducibility, sustainability, and clinical tolerance of ventricular tachycardia. The paper also reviews other therapeutic options for patients with ventricular tachycardia associated with coronary artery disease, including antiarrhythmic drug therapy, surgical ablation, and current implantable cardioverter-defibrillator indications. |
13,807 | A rare case of isolated congenital right ventricular inflow obstruction due to the presence of an intraventricular muscular shelf. | A 56-year-old man presented with anasarca and a 40-lb weight gain that had occurred over the course of 3 to 4 weeks. He had a history of permanent atrial fibrillation and a congenital anomaly of the right ventricular inflow tract. This defect consisted of a muscular shelf in the right ventricular inflow tract, which encased the tricuspid subvalvular apparatus in such a manner that it created tricuspid stenosis. The clinical consequences of this anatomic and hemodynamic situation were a massively dilated right atrium, permanent atrial fibrillation, and clinical evidence of right-sided heart failure, including fluid retention and ascites. The patient underwent surgical resection of the muscular shelf, which was followed by progressive resolution of the ascites and fluid retention. |
13,808 | Multiple left ventricular thrombi in a patient with left ventricular noncompaction. | The major clinical features of myocardial noncompaction are heart failure, arrhythmias, and thromboembolic events. Prominent myocardial trabeculae and deep recesses characteristic of myocardial noncompaction can cause stagnant blood flow and the formation of left ventricular clots. We describe the case of a 62-year-old woman who presented with symptoms of heart failure secondary to left ventricular noncompaction. Transthoracic and transesophageal echocardiography revealed multiple left ventricular thrombi, which had formed despite the patient's long-term therapy with aspirin. Anticoagulative therapy should be considered for patients with myocardial noncompaction who also have risk factors for thromboembolism, such as atrial fibrillation, a history of systemic embolism, or severe left ventricular systolic dysfunction. However, chronic antiplatelet therapy may not sufficiently prevent clot formation in patients who have myocardial noncompaction and severe left ventricular systolic dysfunction. |
13,809 | The causes, treatment, and outcome of acute heart failure in 1006 Africans from 9 countries. | Acute heart failure (AHF) in sub-Saharan Africa has not been well characterized. Therefore, we sought to describe the characteristics, treatment, and outcomes of patients admitted with AHF in sub-Saharan Africa.</AbstractText>The Sub-Saharan Africa Survey of Heart Failure (THESUS-HF) was a prospective, multicenter, observational survey of patients with AHF admitted to 12 university hospitals in 9 countries. Among patients presenting with AHF, we determined the causes, treatment, and outcomes during 6 months of follow-up.</AbstractText>From July 1, 2007, to June 30, 2010, we enrolled 1006 patients presenting with AHF. Mean (SD) age was 52.3 (18.3) years, 511 (50.8%) were women, and the predominant race was black African (984 of 999 [98.5%]). Mean (SD) left ventricular ejection fraction was 39.5% (16.5%). Heart failure was most commonly due to hypertension (n = 453 [45.4%]) and rheumatic heart disease (n = 143 [14.3%]). Ischemic heart disease (n = 77 [7.7%]) was not a common cause of AHF. Concurrent renal dysfunction (estimated glomerular filtration rate, <30 mL/min/173 m(2)), diabetes mellitus, anemia (hemoglobin level, <10 g/dL), and atrial fibrillation were found in 73 (7.7%), 114 (11.4%), 147 (15.2%), and 184 cases (18.3%), respectively; 65 of 500 patients undergoing testing (13.0%) were seropositive for the human immunodeficiency virus. The median hospital stay was 7 days (interquartile range, 5-10), with an in-hospital mortality of 4.2%. Estimated 180-day mortality was 17.8% (95% CI, 15.4%-20.6%). Most patients were treated with renin-angiotensin system blockers but not β-blockers at discharge. Hydralazine hydrochloride and nitrates were rarely used.</AbstractText>In African patients, AHF has a predominantly nonischemic cause, most commonly hypertension. The condition occurs in middle-aged adults, equally in men and women, and is associated with high mortality. The outcome is similar to that observed in non-African AHF registries, suggesting that AHF has a dire prognosis globally, regardless of the cause.</AbstractText> |
13,810 | The effects of 3 different compression methods on intrathoracic pressure in a swine model of ventricular fibrillation. | The aim of this study was to provide a realistic comparison of 3 different extracorporeal compression methods during cardiopulmonary resuscitation on intrathoracic pressure (ITP), hemodynamics, and oxygen metabolism in a swine model of ventricular fibrillation (VF).</AbstractText>Eight minutes after the development of VF, pigs were subjected to 3 different extracorporeal compression methods: traditional artificial manual compression, mechanical compression using an AutoPulse apparatus, or manual sucker. Heart rhythm was assessed by electrocardiography after 5 cycles of extracorporeal compression. If VF still occurred, electrical defibrillation was performed. After defibrillation, an additional 5 cycles of extracorporeal compression were performed. Resuscitation was considered to have failed if the above procedure was continued for 30 minutes without return of spontaneous circulation. Hemodynamics and ITP waveforms were monitored continuously. Oxygen metabolism indices were measured, and success rates were compared among the groups.</AbstractText>Manual compression showed advantages over both of the other methods in terms of maximal ITP and fluctuation amplitude, hemodynamic and oxygen dynamic changes, convenience of administration, and duration of treatment. Survival rates and cerebral performance category scores for the manual compression group were significantly higher than that for the other groups.</AbstractText>Mechanical compression cannot replace traditional artificial manual compression, which remains the preferred method for cardiopulmonary resuscitation.</AbstractText>Copyright © 2013 Elsevier Inc. All rights reserved.</CopyrightInformation> |
13,811 | Mild-to-moderate functional tricuspid regurgitation in patients undergoing mitral valve surgery. | The decision to repair mild-to-moderate functional tricuspid regurgitation (TR) during mitral valve surgery remains controversial. We evaluated the effects of tricuspid valve (TV) repair for functional mild-to-moderate TR during mitral valve surgery.</AbstractText>We enrolled 959 patients with mild-to-moderate functional TR who underwent mitral valve surgery with (repair group n = 431) or without (control group n = 528) concomitant TV repair from January 1994 to September 2010.</AbstractText>There were no significant differences in early mortality or major morbidity rates. Median follow-up was 64.8 months (range, 0.03-203.6 months). After adjustment for baseline characteristics using a propensity score adjustment model, the repair group had similar risks for TV reoperation (hazard ratio [HR], 0.46; 95% confidence interval [CI], 0.10-2.07; P = .31); congestive heart failure (HR, 1.12; 95% CI, 0.37-3.36; P = .84); death (HR, 1.41; 95% CI, 0.82-2.42; P = .22); and the composite of death, TV reoperation, and congestive heart failure (HR, 1.24; 95% CI, 0.76-2.03; P = .39) compared with the control group. On multivariate Cox-regression analysis, old age, atrial fibrillation without a Maze procedure, diabetes mellitus, chronic renal failure, poor left ventricular ejection fraction, and redo surgery emerged as significant independent risk factors for the composite outcome of death, TV reoperation, and congestive heart failure.</AbstractText>Early or late clinical benefits of concomitant TV repair for mild-to-moderate TR during mitral valve surgery were uncertain through a long-term follow-up of 959 patients. Several preoperative factors and the performance of Maze procedure for AF seem to be more important than TV repair in overall clinical outcomes.</AbstractText>Copyright © 2013 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.</CopyrightInformation> |
13,812 | [Action potential duration restitution and the potential association with ventricular arrhythmia in Langendorff-perfused chronic heart failure rabbit hearts]. | To observe the action potential duration restitution (APDR) change and potential association with ventricular arrhythmia (VA) in Langendorff-perfused chronic heart failure rabbit hearts.</AbstractText>Male rabbits were randomly divided into two groups: control (CTL, n=15) group and chronic heart failure (CHF, n=15) group. CHF was induced by injecting isoproterenol (300 µg×kg(-1) ×d(-1)) for 14 days. Four weeks later, cardiac function and structure change of both groups were assessed by echocardiography. In the whole Langendorff-perfused hearts, the monophasic action potential (MAP) and the effective refractory period (ERP) were recorded from left anterior basal ventricle, left anterior free wall, left anterior apex and left posterior basal ventricle, left posterior free wall and left posterior apex, the APD curves were also constructed in both groups; at the six sites of every isolated heart, the programmed electrical stimulation and burst pacing were used to induce action potential duration (APD) alternans and VA, respectively.</AbstractText>Left ventricular ejection was reduced and end-dimension was enlarged in rabbits of CHF group. Compared with the same sites of CTL group, the 90% of MAP duration (MAPD90), the ERP, the max slope (Smax) of APDR curves, the pacing cycle length of inducing the APD alternans and the VAs were significantly increased (all P<0.05) in CHF group; the spatial dispersions of MAPD90, ERP and Smax of APDR curves in CHF group were also greater than in CTL group (all P<0.05).</AbstractText>The ventricular APD alternans might be linked with occurrence of the VA in CHF rabbits. Increase of the Smax from APDR curves and the spatial dispersions of Smax in this CHF model might facilitate the development of ventricular arrhythmia.</AbstractText> |
13,813 | Potassium induced cardiac standstill during conventional cardiopulmonary resuscitation in a pig model of prolonged ventricular fibrillation cardiac arrest: a feasibility study. | Potassium-based cardioplegia has been the gold standard for cardioprotection during cardiac surgery. We sought to evaluate the feasibility and the effects of potassium-induced cardiac standstill during conventional cardiopulmonary resuscitation (CPR) in a pig model of prolonged ventricular fibrillation (VF).</AbstractText>VF was induced in 20 pigs, and circulatory arrest was maintained for 14 min. Animals were then resuscitated by standard CPR. Coincident with the start of CPR, 20 ml of saline (control group) or 0.9 mequiv.kg(-1) of potassium chloride diluted to 20 ml (potassium group) was administered into right atrium.</AbstractText>Administration of potassium resulted in asystole lasting for 1.0 min (0.2) in the potassium group animals. VF reappeared in all but one animal, in which wide QRS complex bradycardia followed. Restoration of spontaneous circulation (ROSC) was attained in two animals (20%) in the control group and in seven animals (70%) in the potassium group (p=0.070). Resuscitated animals in the potassium group required fewer countershocks (3, 4 vs. 2 (1-2)), smaller doses of adrenaline (1.84, 1.84 vs. 0.94 (0.90-1.00)mg), and shorter duration of CPR (8, 10 vs. 4.0 (4.0-4.0)min) than did the control group. Potassium concentrations normalised rapidly after ROSC in both groups, and the potassium concentrations at 5 min (5.5, 6.6 vs. 6.8 (6.5-7.8)mequiv.l(-1)) and 4h (4.9, 5.4 vs. 5.9 (5.1-6.4)mequiv.l(-1)) after ROSC were similar in the both groups.</AbstractText>In a pig model of untreated VF cardiac arrest for 14 min, resuscitation with potassium-induced cardiac standstill during conventional CPR was found to be feasible.</AbstractText>Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
13,814 | Ivabradine but not propranolol delays the time to onset of ischaemia-induced ventricular fibrillation by preserving myocardial metabolic energy status. | Heart rate reduction (HRR) has shown a beneficial impact on the prevention of ventricular fibrillation, which could be explained by increased myocardial blood flow and preservation of mitochondrial structure. Here, we assessed the HRR impact on time to onset of ventricular fibrillation (TOVF) and myocardial metabolic energy status.</AbstractText>An acute myocardial ischaemia was induced in pigs until ventricular fibrillation onset and TOVF was then measured. High-energy phosphates were measured in ventricular samples from the ischaemic region by nuclear magnetic resonance. Saline, ivabradine (IVA, a selective heart rate-lowering agent) and propranolol (PROPRA, a β-blocker) were administered intravenously, 30 and 60 min respectively prior to ischaemia to ensure stable HRR. To study specifically the HRR impact, another set of animals received IVA and was submitted to rapid atrial pacing (200 bpm) to abolish HRR. IVA and PROPRA induced a similar HRR (IVA: 22-26%, PRORA: 20-21%, p<0.01 vs. control), which was associated with a significant increase in TOVF with IVA (2325s) compared to PROPRA (682s) and saline (401s). This effect was abolished by atrial pacing performed during ischaemia and throughout the entire experimental session. Only IVA partially prevented the decrease in phosphocreatine-to-ATP ratio (CrP/ATP) ratio and the ADP accumulation at the onset of ventricular fibrillation. Finally, CrP/ATP ratio levels were correlated with TOVF (r=0.74, p<0.001).</AbstractText>Unlike PROPRA, IVA delayed the time to onset of ischaemia-induced ventricular fibrillation by preserving myocardial energy status, supporting the pertinence of IVA in the management of patients with coronary artery disease.</AbstractText>Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
13,815 | Falsely pessimistic prognosis by EEG in post-anoxic coma after cardiac arrest: the borderland of nonconvulsive status epilepticus. | Prognostication following anoxic coma relies on clinical assessment and is assisted by neurophysiology. A non-evolving EEG spike burst/isoelectric suppression pattern after the first 24 hours almost invariably indicates poor outcome, while an evolving pattern implies nonconvulsive status epilepticus (NCSE) that may "hide" surviving brain activity and is amenable to treatment.</AbstractText>We present the case of a 53-year-old woman who had a witnessed out-of-hospital ventricular fibrillation cardiac arrest, was resuscitated by paramedics, but remained comatose. An EEG, performed 36 hours post-insult, showed an unremitting, non-evolving, unresponsive 2-6 Hz high-voltage spike burst/isoelectric suppression pattern, which remained unchanged at 96 hours post-insult, following therapeutic hypothermia. During this period, she was completely off sedation and taking triple antiepileptic treatment, without systemic confounding disorders. Although the initial pattern was indicative of poor neurological outcome, she eventually made meaningful functional recovery; the last EEG showed satisfactory background rhythms and stimulus-induced epileptiform discharges without seizures.</AbstractText>In post-anoxic coma, non-evolving >2 Hz spike burst/isoelectric suppression pattern may still reflect NCSE and therefore should be considered in the diagnostic EEG criteria for NCSE. Such borderline patterns should not dissuade physicians from intensifying treatment until more confident prognostication can be made.</AbstractText> |
13,816 | Load-distributing band improves ventilation and hemodynamics during resuscitation in a porcine model of prolonged cardiac arrest. | The use of mechanical cardiopulmonary resuscitation (CPR) has great potential for the clinical setting. The purpose of present study is to compare the hemodynamics and ventilation during and after the load-distributing band CPR, versus the manual CPR in a porcine model of prolonged cardiac arrest, and to investigate the influence of rescue breathing in different CPR protocols.</AbstractText>Sixty-four male pigs (n = 16/group), weighing 30 ± 2 kg, were induced ventricular fibrillation and randomized into four resuscitation groups: continuous load-distributing band CPR without rescue ventilation (C-CPR), load-distributing band 30:2 CPR (A-CPR), load-distributing band CPR with continuous rescue breathing (10/min) (V-CPR) or manual 30:2 CPR (M-CPR). Respiratory variables and hemodynamics were recorded continuously; blood gas was analyzed.</AbstractText>Tidal volume produced by compressions in the A-, C- and V-CPR groups were significantly higher compared with the M-CPR group (all p < 0.05). Coronary perfusion pressure of the V-CPR group was significantly lower than the C-CPR group (p < 0.01), but higher than the M-CPR group. The increasing of lung dead space after restoration of spontaneous circulation was significantly greater in the M-CPR group compared with the A-, C- and V-CPR groups (p < 0.01). Blood pH gradually decreased and was lower in the M-CPR group than that in the A-, C- and V-CPR groups (p < 0.01). PaO2 of the A-, C- and V-CPR groups were significantly higher and PaCO2 were significantly lower compared with the M-CPR (both p < 0.05). Cerebral performance categories were better in the A-, C- and V-CPR groups compared with the M-CPR group (p < 0.0001).</AbstractText>The load-distributing band CPR significantly improved respiratory parameters during resuscitation by augmenting passive ventilation, and significantly improved coronary perfusion pressure. The volume of ventilation produced by the load-distributing band CPR was adequate to maintain sufficient gas exchange independent of rescue breathing.</AbstractText> |
13,817 | Single-beat determination of global longitudinal speckle strain in patients with atrial fibrillation. | Although global left ventricular (LV) systolic function is an important determinant of outcome, the assessment of global longitudinal speckle strain (GLS) in patients with atrial fibrillation (AF) is unreliable because of beat-to-beat variation. Previous studies have confirmed that LV contractility of each irregular beat is predicted from the ratio of preceding R-R (RR1) to pre-preceding R-R (RR2) intervals, and the value when the intervals are equal (RR1/RR2 = 1) estimates the average value of LV contractility. The aim of this study was to assess the clinical feasibility of an index that is obtained on the basis of the RR1/RR2 ratio for the estimation of GLS in patients with AF.</AbstractText>We evaluated the RR1/RR2 ratio for the measurement of GLS with apical 4-chamber views in 20 patients with AF. We obtained the GLS for ≥13 cardiac cycles, and the relationship between each GLS at a given cardiac beat and the RR1/RR2 ratio was evaluated by linear regression analysis. The value of GLS at RR1/RR2 = 1 was compared with the measured average value.</AbstractText>The GLS showed a significant correlation with the RR1/RR2 ratio (r = -0.80). The calculated value of GLS at RR1/RR2 = 1 was quite similar to the average value (-10.17 ± 2.1 % vs. -10.06 ± 2.1 %). The GLS of a single beat with identical RR1 and RR2 intervals showed a significant correlation compared with the measured average value over all cardiac cycles (r = 0.94, y = 0.90x - 0.97).</AbstractText>The GLS at RR1/RR2 = 1 allows the LV systolic parameter to be accurately evaluated during AF and obviates the less reliable process of averaging multiple irregular beats.</AbstractText> |
13,818 | Defibrillation Testing During Defibrillator Implantation. | Implantable cardioverter defibrillators (ICDs) terminate ventricular tachycardia (VT) and ventricular fibrillation (VF) with high efficacy. ICDs improve mortality in patients after survived sudden cardiac death (SCD) and in patients at high risk of dying suddenly. All trials which show a benefit of ICD therapy, have performed some kind of defibrillation testing in order to prove correct system function, sensing of VF and effective defibrillation. Current devices show a shock efficacy of 80-90 % for singular shocks and devices provide up to seven rescue shocks. The probability that a device does not terminate an episode of VT or VF should therefore be very low. However, it is difficult to abandon defibrillation testing because prospective data is lacking that demonstrate non-inferiority, if ICDs are implanted without some kind of test. Two prospective trials are on the way and will be finish by 2013/14: the SIMPLE and NORDIC trial, which will answer the question if defibrillation testing can be abandoned without any effect on the benefit of ICD therapy or if testing may even be harmful. |
13,819 | Risk Stratification in Atrial Fibrillation Patients - A Review Focused on Mortality. | Atrial fibrillation (AF) is associated with increased mortality that is largely due to the severe co-morbidities of patients with this rhythm disturbance rather than to its electrocardiographic features. Available evidence indicated that ageing, heart failure and stroke are the most important predictors of all-cause mortality. Additional clinical parameters such as smoking, renal impairment, chronic obstructive pulmonary disease may also identify patients at risk. The prevention of thromboembolic events is based on oral anticoagulant therapy, which reduces the severity and mortality of ischaemic strokes but slightly increase the rate of haemorrhagic events. Most of the traditional risk stratifiers commonly used in patients in sinus rhythm such as New York Heart Association (NYHA) functional class, left ventricular ejection fraction (LVEF) and resting heart rate seem to be less effective in AF patients thus leaving to the physician judgment the main responsibility of identifying patients with an increased mortality risk. |
13,820 | The implementation of therapeutic hypothermia in the emergency department: a multi-institution case review. | The use of therapeutic hypothermia (TH) is a burgeoning treatment modality for post-cardiac arrest patients.</AbstractText>We performed a retrospective chart review of patients who underwent post-cardiac arrest TH at eight different institutions across the United States. Our objectives were to assess how TH is currently being implemented in emergency departments and to examine the feasibility of conducting TH research using multi-institution prospective data.</AbstractText>A total of 94 cases were identified in a 3-year period and submitted for review by participating institutions of the Peri-Resuscitation Consortium. Of those, seven charts were excluded for missing data. Two independent reviewers performed the data abstraction. Results were subsequently compared, and discrepancies were resolved by a third reviewer. We assessed patient demographics, initial presenting rhythm, time until TH initiation, duration of TH, cooling methods and temperature reached, survival to hospital discharge, and neurological status on discharged.</AbstractText>The majority of cases had initial cardiac rhythms of asystole or pulseless electrical activity (55.2%), followed by ventricular tachycardia or fibrillation (34.5%). The inciting cardiac rhythm was unknown in 10.3% of cases. Time to initiation of TH ranged from 0 to 783 minutes with a mean time of 99 minutes (SD=132). Length of TH ranged from 25 to 2,171 minutes with a mean time of 1,191 minutes (SD=536). The average minimum temperature achieved was 32.5°C, with a range from 27.6°C to 36.7°C (SD=1.5°C). Of the 87 charts reviewed, 29 (33.3%) of the patients survived to hospital discharge.</AbstractText>The implementation of TH across the country is extremely varied with no universally accepted treatment. While our study is limited by sample size, it illustrates some compelling trends. A large, prospective, multicenter trial or registry is necessary to elucidate further the optimal parameters for TH and its benefit in various population subsets.</AbstractText> |
13,821 | Effect of lesional differences in prolapsed leaflets on clinical outcomes in patients with mitral valve prolapse. | Mitral valve prolapse (MVP) is usually benign, although serious complications may occur. It remains unclear whether the region of prolapsed mitral leaflets might affect prognosis. The aim of this study was to investigate lesional differences of clinical courses of MVP.</AbstractText>We retrospectively investigated 128 MVP patients who had been followed up for for a mean of 56.4 months. They were classified into prolapse of the anterior mitral leaflet (AML, n = 59), posterior mitral leaflet (PML, n = 47), or both leaflets (AML & PML, n = 22). Echocardiographic and clinical data were examined from medical records. Average time to clinical events; MV surgery, new onset of atrial fibrillation (AF), echocardiographic evidence of new chordal rupture, and worsening of mitral regurgitation severity were all significantly shorter in PML prolapse than in those with AML or AML & PML prolapses. Increases in the left ventricular dimensions and estimated pulmonary arterial systolic pressures were significantly larger in PML prolapse, compared with AML or AML & PML prolapses. A subanalysis of PML prolapse revealed that new chordal rupture tended to be more frequent in middle scallop prolapse (48%) compared with lateral and medial scallops (18%). In contrast, new onset of AF tended to occur in lateral and medial scallop prolapses (44%) compared with middle scallop prolapse (20%).</AbstractText>PML prolapse patients had a poor outcome, compared with AML or AML & PML prolapse patients. Precise regional evaluation of the prolapsed leaflets may predict cardiac complications in MVP.</AbstractText> |
13,822 | Activation of εPKC reduces reperfusion arrhythmias and improves recovery from ischemia: optical mapping of activation patterns in the isolated guinea-pig heart. | Pervious biochemical and hemodynamic studies have highlighted the important role of εPKC in cardioprotection during ischemic preconditioning. However, little is known about the electrophysiological consequences of εPKC modulation in ischemic hearts. Membrane permeable peptide εPKC selective activator and inhibitor were used to investigate the role of εPKC modulation in reperfusion arrhythmias.</AbstractText>Protein transduction domain from HIV-TAT was used as a carrier for peptide delivery into intact Langendorff perfused guinea pig hearts. Action potentials were imaged and mapped (124 sites) using optical techniques and surface ECG was continuously recorded. Hearts were exposed to 30 min stabilization period, 15 min of no-flow ischemia, followed by 20 min reperfusion. Peptides (0.5 μM) were infused as follows: (a) control (vehicle-TAT peptide; TAT-scrambled ψεRACK peptide); (b) εPKC agonist (TAT-ψεRACK); (c) εPKC antagonist (TAT-εV1).</AbstractText>Hearts treated with εPKC agonist ψεRACK had reduced incidence of ventricular tachycardia (VT, 64%) and fibrillation (VF, 50%) compared to control (VT, 80%, P<0.05) and (VF, 70%, P < 0.05). However, the highest incidence of VT (100%, P < 0.05) and VF (80%) occurred in hearts treated with εPKC antagonist peptide εV1 compared to control and to εPKC agonist ψεRACK. Interestingly, at 20 min reperfusion, 100% of hearts treated with εPKC agonist ψεRACK exhibited complete recovery of action potentials compared to 40% (P < 0.05) of hearts treated with εPKC antagonist peptide, εV1 and 65% (P < 0.5) of hearts in control. At 20 min reperfusion, maps of action potential duration from εPKC agonist ψεRACK showed minimal dispersion (48.2 ± 9 ms) compared to exacerbated dispersion (115.4 ± 42 ms, P < 0.05) in εPKC antagonist and control (67 ± 20 ms, P<0.05). VT/VF and dispersion from hearts treated with scrambled agonist or antagonist peptides were similar to control.</AbstractText>The results demonstrate that εPKC activation by ψεRACK peptide protects intact hearts from reperfusion arrhythmias and affords better recovery. On the other hand, inhibition of εPKC increased the incidence of arrhythmias and worsened recovery compared to controls. The results carry significant therapeutic implications for the treatment of acute ischemic heart disease by preconditioning-mimicking agents.</AbstractText>Published by Elsevier Inc.</CopyrightInformation> |
13,823 | Effects of n-3 Polyunsaturated Fatty Acids on Cardiac Ion Channels. | Dietary n-3 polyunsaturated fatty acids (PUFAs) have been reported to exhibit antiarrhythmic properties, and these effects have been attributed to their capability to modulate ion channels. In the present review, we will focus on the effects of PUFAs on a cardiac sodium channel (Na(v)1.5) and two potassium channels involved in cardiac atrial and ventricular repolarization (K(v)) (K(v)1.5 and K(v)11.1). n-3 PUFAs of marine (docosahexaenoic, DHA and eicosapentaenoic acid, EPA) and plant origin (alpha-linolenic acid, ALA) block K(v)1.5 and K(v)11.1 channels at physiological concentrations. Moreover, DHA and EPA decrease the expression levels of K(v)1.5, whereas ALA does not. DHA and EPA also decrease the magnitude of the currents elicited by the activation of Na(v)1.5 and calcium channels. These effects on sodium and calcium channels should theoretically shorten the cardiac action potential duration (APD), whereas the blocking actions of n-3 PUFAs on K(v) channels would be expected to produce a lengthening of cardiac action potential. Indeed, the effects of n-3 PUFAs on the cardiac APD and, therefore, on cardiac arrhythmias vary depending on the method of application, the animal model, and the underlying cardiac pathology. |
13,824 | J-waves in patients with an acute ST-elevation myocardial infarction who underwent successful percutaneous coronary intervention: prevalence, pathogenesis, and clinical implication. | The prevalence, clinical significance, and pathogenesis of J-waves were studied in the patients with an ST-elevation myocardial infarction (MI) after percutaneous coronary intervention (PCI).</AbstractText>One hundred and fifty-two consecutive patients with an acute ST-elevation MI were included. The mean age was 68.6 ± 13.5 years, and 78.3% of the patients were male. Following successful PCI, 12-lead electrocardiograms (ECGs) were monitored, and J-waves were measured 1 week after the MI and analysed in relation to the location of the MI and arrhythmias. Clinical and ECG parameters were compared between the groups with and without J-waves. The rate dependency of the J-wave amplitude was analysed in the conducted atrial premature beats (APBs). J-waves were present in 60.5% (≥0.1 mV) or 48.9% (≥0.2 mV) of the 152 patients. The J-waves were more often located in the inferior leads and more frequently in an inferior MI. The presence of J-waves was associated with ventricular arrhythmias, including ventricular fibrillation. The J-wave amplitude increased in the conducted APB, mechanistically suggesting a phase 3 block.</AbstractText>Many patients in the early recovery phase after an acute MI had J-waves. This ECG phenomenon was associated with an increased incidence of ventricular arrhythmias. The tachycardia-dependent augmentation of the J-wave amplitude suggested a mechanistic role of conduction delay.</AbstractText> |
13,825 | Mitral valve surgery: wait and see vs. early operation. | Mitral valve repair represents the optimal surgical treatment for severe degenerative mitral regurgitation. According to the current guidelines, mitral repair is indicated in the presence of symptoms and/or signs of left ventricular (LV) dysfunction. In asymptomatic patients with preserved LV function, surgery should be considered in the presence of atrial fibrillation (AF) and/or pulmonary hypertension. In asymptomatic patients with preserved LV function, normal pulmonary artery pressure, and no episodes of AF, surgical timing is still an object of debate. The controversial issue is whether, in those circumstances, a 'wait and see (watchful waiting)' approach should be followed or an 'early repair' policy should be preferred. Indeed, a randomized trial comparing the two strategies has never been performed. In the absence of evidence-based arguments definitely supporting any particular course of action, advantages, drawbacks, and requirements for both strategies will be discussed in this review on the basis of the most significant observational studies which have focused on this issue. |
13,826 | Effect of plant polyphenols on ischemia-reperfusion injury of the isolated rat heart and vessels. | In the present study, we investigated the potential protective effect of selected natural substances in a rat model of heart and mesenteric ischemia-reperfusion (I/R). Experiments were performed on isolated Langendorff-perfused rat hearts, subjected to 30-min global ischemia, followed by 30-min reperfusion. Arbutin, curcumin, rosmarinic acid and extract of Mentha x villosa were applied in the concentration of 1 × 10⁻⁵ mol/l 10 min before the onset of ischemia and during reperfusion, through the perfusion medium. Mesenteric ischemia was induced by clamping the superior mesenteric artery (SMA) for 60 min, subsequent reperfusion lasted 30 min. Production of reactive oxygen species (ROS) by SMA ex vivo was determined by luminol-enhanced chemiluminiscence (CL). The effect of the substances was tested after their incubation with tissue. Curcumin and extract of Mentha x villosa were found to be the most effective in reducing reperfusion-induced dysrhythmias--ventricular tachycardia and fibrillation. This effect was accompanied by bradycardic effect. The mesenteric I/R induced an increase in CL in vascular tissue which was dampened by substances tested. All substances tested were found to have antioxidant properties, as demonstrated by a reduction in ROS production in mesenteric vessels. This effect was confirmed in curcumin and extract of Mentha x villosa which reduced reperfusion dyshythmias. |
13,827 | Minimally invasive hybrid ablation procedure for the treatment of persistent atrial fibrillation: one year results. | The concept of a hybrid approach, combining the most effective techniques of surgical and endocardial catheter ablation has resulted in the creation of the convergent ablation procedure. This novel, pericardioscopic, hybrid approach can be an effective option for highly symptomatic patients with persistent atrial fibrillation (PSAF) and longstanding persistent atrial fibrillation (LSPAF) for whom standalone surgical or endocardial ablation procedures offer sometimes unsatisfactory outcomes.</AbstractText>To assess the safety, efficacy and effectiveness of a hybrid epicardial and endocardial radiofrequency ablation for the treatment of PSAF and LSPAF.</AbstractText>Single-centre, prospective, non-randomised clinical study. Between August 2009 and December 2011, 27 patients with PSAF (n = 5) and LSPAF (n = 22) underwent hybrid ablation (HABL). Mean age was 52.52 ± 11.27 years, and the mean EHRA class was 2.5; 14 (51.8%) patients had a history of electrical cardioversion (n = 6) or catheter ablation (n = 8). Five patients had left ventricular ejection fraction (LVEF) of less than 35%. Mean AF duration for all patients was 3.46 ± 2.5 years. All patients were on antiarrhythmic drugs (AAD) and oral anticoagulation. Patients were scheduled for three, six and 12 month follow-up with seven day Holters, REVEAL® XT and ECHO measurements.</AbstractText>The HABL procedure was feasible in all patients. At six months post procedure, 72.2% (13/18) of patients were in SR, and 66.5% (12/18) were off class I/III AADs. Four patients were in AF and one patient developed right atrial flutter. At one year post procedure, 80% (8/10) of patients were in SR and off class I/III AADs. At two year post procedure, 100% (6/6) of patients were in SR and off class I/III AADs. Rapid change in left ventricular function was noted in patients with low LVEF (≤ 35%) prior to the procedure. Patients with LVEF +40% had less apparent improvement.</AbstractText>Hybrid, epicardial and endocardial, radiofrequency ablation is feasible and safe, effectively restoring sinus rhythm in the vast majority of patients with PSAF and LSPAF.</AbstractText> |
13,828 | The problem of indeterminate microvolt T-wave alternans results in patients with left ventricular dysfunction referred for implantable cardioverter-defibrillator implantation in the primary prevention of sudden cardiac death. | Microvolt T-wave alternans (MTWA) is a recommended noninvasive diagnostic test for predicting the risk of sudden cardiac death (SCD). However, about 6% to 41% of MTWA results are indeterminate. The causes, interpretation and clinical significance of these results have not been not clearly established.</AbstractText>To assess frequency, causes, and prognostic significance of indeterminate MTWA results in a group of patients with left ventricular dysfunction referred for implantable cardioverter-defibrillator (ICD) placement in the primary prevention of SCD.</AbstractText>Patients with left ventricular ejection fraction (LVEF) ≤ 35% underwent MTWA evaluation during a treadmill exercise test (CH2000 system, Cambridge Heart Inc. Bedford MA, USA). MTWA results (spectral analysis) were categorised as positive, negative, or indeterminate (MTWApos, MTWAneg, and MTWAnd, respectively). Patients were followed up for the occurrence of SCD, ventricular tachycardia (VT), and ventricular fibrillation (VF).</AbstractText>Mean age of participants (n = 93) was 63 ± 13 years, an ischaemic cause of left ventricular dysfunction was present in 70 (75%) patients, and average LVEF was 30 ± 7%. MTWApos was found in 27 (29%) patients, MTWAneg in 41 (44%) patients, and MTWAnd in 25 (27%) patients. Causes of MTWAnd included inability to achieve a diagnostic HR in 12 (48%) patients, ventricular ectopy in 5 (20%) patients, nonsustained alternans in 3 (12%) patients, and technical factors (artifacts due to a high noise level) in 5 patients (20% of indeterminate results, 5.4% of the whole study group). During follow-up, 8 SCD/VT/VF events were noted (4 patients with MTWApos and 4 patients with MTWAnd due to patient-related factors). The rate of SCD/VT/VF was 35% in patients with MTWApos and 34.6% in MTWAnd due to patients-related factors, significantly higher compared to those with MTWAneg or MTWAnd due to technical factors (p 〈 0.05).</AbstractText>Although the proportion of indeterminate MTWA results in patients with left ventricular dysfunction referred for ICD implantation in the primary prevention of SCD was high, the proportion of indeterminate MTWA results due to technical factors, probably of no prognostic significance, was small.</AbstractText> |
13,829 | Ibutilide decreases defibrillation threshold by the reduction of activation pattern complexity during ventricular fibrillation in canine hearts. | Ibutilide has been commonly used for pharmacologic cardioversion of atrial fibrillation and flutter in clinical settings. The objective of this study was to investigate the effects of ibutilide on the defibrillation threshold (DFT), restitution properties, dispersion of refractoriness and activation patterns during ventricular fibrillation (VF).</AbstractText>Ibutilide was administrated intravenously in six open-chest beagles. Before and after the drug administration, 20-second episodes of VF were electrically induced and recorded with a 10×10 unipolar electrode plaque sutured on the lateral epicardium of the left ventricle. DFT and VF activation patterns, including type of epicardial activation maps, VF cycle length (VF-CL), conduction velocity, wavelength (WL) and reentry incidence, were measured. Restitution properties and dispersion of refractoriness were estimated from activation recovery intervals (ARI) during pacing.</AbstractText>Compared to baseline, ibutilide markedly decreased the DFT by 31% ((491 ± 14) V vs. (337 ± 59) V, P < 0.01). The drug significantly reduced the maximal slope of the restitution curve (1.34 ± 0.08 vs. 0.76 ± 0.06, P < 0.01) and its epicardial dispersion (0.36 ± 0.09 vs. 0.21 ± 0.06, coefficient of variation, P = 0.03). The dispersion of refractoriness was enhanced at the pacing cycle length of 300 ms to 160 ms by ibutilide. The drug significantly increased the VF-CL ((96 ± 19) ms vs. (112 ± 20) ms, P < 0.01) and the WL ((41 ± 9) mm vs. (52 ± 14) mm, P = 0.02) during VF, and reduced the reentry incidence by 25% (0.08 ± 0.02 vs. 0.06 ± 0.02, P < 0.01). In the epicardial activation maps, ibutilide significantly reduced the percentage of more complex activation maps during VF.</AbstractText>Intravenous ibutilide significantly decreased the DFT. It might be due to reduction of activation pattern complexity during VF.</AbstractText> |
13,830 | Thrombolysis of ischemic stroke from noncompaction in metabolic myopathy. | Ischemic stroke has not been reported together with left ventricular hypertrabeculation/noncompaction (LVHT) and metabolic myopathy.</AbstractText>In a 32-year-old woman with suspected metabolic myopathy, congenital AV-block, pacemaker implantation at the age of 20, and reduced systolic function, LVHT was detected on echocardiography. Shortly afterward, the patient had a left-sided ischemic stroke and underwent systemic thrombolysis with rTPA 3.5 hours after the onset. After the exclusion of potential causes of stroke, cerebral thromboembolism was attributed to LVHT. Oral anticoagulation was initiated and a cardiac resynchronization system was implanted.</AbstractText>LVHT patients with systolic dysfunction or atrial fibrillation experiencing an ischemic stroke may benefit from oral anticoagulation.</AbstractText> |
13,831 | Effect of matrix metalloproteinase and their inhibitors on atrial myocardial structural remodeling. | To explore the expression of matrix metalloproteinase and tissue inhibitor of metalloproteinase of atrial myocardial structure of rheumatic and coronary heart disease.</AbstractText>Fifty patients with rheumatic heart disease (RHD) undergoing artificial mitral valve replacement surgery were selected: 20 with sinus rhythm and 30 with atrial fibrillation. Another 40 patients with coronary artery disease (CAD) undergoing coronary artery bypass surgery were selected: 22 with myocardial infarction (MI) and 18 with unstable angina. During thoractomy, samples of the right auricle were taken and immunohistochemical staining and fluorescence quantitative PCR were performed to test matrix metalloproteinase (MMP) 1, MMP-3, MMP-7, MMP-9, tissue inhibitor of metalloproteinase (TIMP) 1, TIMP-2, TIMP-3 and TIMP-4 expression of the samples.</AbstractText>In RHD, the left and right atrial diameters of the atrial fibrillation group were significantly larger than those of the sinus rhythm group (P < 0.01), but there was no significant difference between the left ventricular diastolic diameter and the left ventricular ejection. The immunohistochemical staining and real-time (RT)-PCR show that the expression of MMP-3, MMP-7, MMP-9, TIMP-1, TIMP-2, TIMP-3 and TIMP-4 were significantly increased in the atrial fibrillation group compared with the sinus rhythm group (all P < 0.01). The difference in MMP-1 of the two groups was not statistically significant. In CAD patients, the left and right atrial diameters and left ventricular diameter of the MI group were significantly larger than those of the unstable angina group (P < 0.01), but the left ventricular ejection fraction was obviously lower than that of the unstable angina group (P < 0.05). Immunohistochemical staining and RT-PCR show that the expression of MMP-3, MMP-9, TIMP-1 TIMP-2, TIMP-3, TIMP-4 were significantly increased in MI group compared with the unstable angina (P < 0.01, P < 0.01, P < 0.05, P < 0.05, P < 0.01 and P < 0.01, respectively).</AbstractText>The expression of MMPs and TIMPs increased in RHD patients and MI patients. Regulating the expression and activity of MMPs and TIMPs may be an important clinical treatment and method to prevent, and even reverse, atrial remodeling.</AbstractText> |
13,832 | An echo state neural network for QRST cancellation during atrial fibrillation. | A novel method for QRST cancellation during atrial fibrillation (AF) is introduced for use in recordings with two or more leads. The method is based on an echo state neural network which estimates the time-varying, nonlinear transfer function between two leads, one lead with atrial activity and another lead without, for the purpose of canceling ventricular activity. The network has different sets of weights that define the input, hidden, and output layers, of which only the output set is adapted for every new sample to be processed. The performance is evaluated on ECG signals, with simulated f-waves added, by determining the root mean square error between the true f-wave signal and the estimated signal, as well as by evaluating the dominant AF frequency. When compared to average beat subtraction (ABS), being the most widely used method for QRST cancellation, the performance is found to be significantly better with an error reduction factor of 0.24-0.43, depending on f-wave amplitude. The estimates of dominant AF frequency are considerably more accurate for all f-wave amplitudes than the AF estimates based on ABS. The novel method is particularly well suited for implementation in mobile health systems where monitoring of AF during extended time periods is of interest. |
13,833 | Very long-term results (up to 17 years) with the double-orifice mitral valve repair combined with ring annuloplasty for degenerative mitral regurgitation. | The very long-term results of the double-orifice mitral valve repair are unknown. The aim of this study was to assess the late clinical and echocardiographic outcomes of this technique in patients with degenerative mitral regurgitation.</AbstractText>From 1993 to 2000, 174 patients with severe degenerative mitral regurgitation were treated with the double-orifice technique combined with ring annuloplasty. Mean age of patients was 52 ± 12.8 years, New York Heart Association class I or II was present in 71% of the patients, atrial fibrillation in 17.2%, and preoperative left ventricular ejection fraction was 59.5% ± 7.5%. Mitral regurgitation was due to anterior leaflet prolapse in 36 patients (20.6%), bileaflet prolapse in 128 (73.5%), and posterior leaflet prolapse in 10 patients (5.7%).</AbstractText>There were no hospital deaths. At hospital discharge, mitral regurgitation was absent or mild in 169 patients (97.1%) and moderate (2+/4+) in 5 patients (2.8%). Mitral stenosis requiring reoperation was detected in 1 patient (0.6%). Clinical and echocardiographic follow-up was 97.1% complete (mean length, 11.5 ± 2.53 years; median, 11.6 years; longest duration, 17.6 years). At 14 years, actuarial survival was 86.9% ± 3.37%, freedom from cardiac death was 95.8% ± 1.54%, and freedom from reoperation was 89.6 ± 2.51%. At the last echocardiographic examination, recurrence of mitral regurgitation ≥3+ was documented in 23 patients (23/169, 13.6%). Freedom from mitral regurgitation ≥3+ at 14 years was 83.8% ± 3.39%. The only predictor of recurrence of mitral regurgitation ≥3+ was residual mitral regurgitation greater than mild at hospital discharge (hazard ratio, 5.7; 95% confidence interval, 1.6-20.6; P = .007).</AbstractText>The double-orifice repair combined with ring annuloplasty provides very satisfactory long-term results in patients with degenerative mitral regurgitation in the setting of bileaflet and anterior leaflet prolapse.</AbstractText>Copyright © 2012 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.</CopyrightInformation> |
13,834 | Pediatric prehospital evaluation of NYC cardiac arrest survival (PHENYCS). | The objective of this study was to describe the demographics of out-of-hospital cardiac arrests (OOHCAs) in children younger than 18 years and characteristics associated with survival among these children in New York City (NYC).</AbstractText>A prospective observational cohort of all children younger than 18 years with OOHCA in NYC between April 1, 2002, and March 31, 2003. Data were collected from prehospital providers by trained paramedics utilizing a previously validated telephone interview process. Data included Pediatric Utstein core measures and critical prehospital time intervals. Analyses utilized descriptive statistics and bivariate association with survival.</AbstractText>Resuscitation was attempted on 147 pediatric OOHCA patients in NYC during the study period; outcome data were collected on these patients. The median age was 2 years; most (58%) were male. The majority of arrests occurred at home (69%). Lay bystanders witnessed 33% of all OOHCA; 68% of witnesses were family members. Bystander cardiopulmonary resuscitation (CPR) was performed on 30% of children. Median emergency medical services response time was 3.6 minutes (range, 0.4-14.4 minutes). Initial rhythm was as follows: ventricular fibrillation, 2%; asystole, 50%; pulseless electrical activity, 9.5%; other rhythms, 11.6%; no rhythm recorded, 26%. Survival was 4% to hospital discharge and was present only among witnessed arrests (6/58 witnessed vs 0/70 unwitnessed, P < 0.05).</AbstractText>Pediatric OOHCA survival rate is low. Witnessed arrest was the most important determinant of survival. Ventricular fibrillation was an uncommon rhythm measured by emergency medical services. The majority of arrests occurred at home. The rate of bystander CPR was low. Strategies to increase the rate of bystander CPR for children, especially by family members, are needed.</AbstractText> |
13,835 | Slow ventricular response atrial fibrillation related to mad honey poisoning. | Mad honey poisoning which is induced by Grayanotoxin (Andromedotoxin), is also known to have adverse effects in the cardiovascular system leading to different clinical entities. This toxin is produced by a member of the Rhododendron genus of plants of two R. Luteum and R. Panticum. In this article, we presented a case of slow ventricular response atrial fibrillation complaints with nausea, vomiting, dizziness and chest pain about an hour after eating honey produced in the Black Sea Region. |
13,836 | Role for MicroRNA-21 in atrial profibrillatory fibrotic remodeling associated with experimental postinfarction heart failure. | Atrial tissue fibrosis is often an important component of the atrial fibrillation (AF) substrate. Small noncoding microRNAs are important mediators in many cardiac remodeling paradigms. MicroRNA-21 (miR-21) has been suggested to be important in ventricular fibrotic remodeling by downregulating Sprouty-1, a protein that suppresses fibroblast proliferation. The present study examined the potential role of miR-21 in the atrial AF substrate resulting from experimental heart failure after myocardial infarction (MI).</AbstractText>Large MIs (based on echocardiographic left ventricular wall motion score index) were created by left anterior descending coronary artery ligation in rats. Changes induced by MI versus sham controls were first characterized with echocardiography, histology, biochemistry, and in vivo electrophysiology. Additional MI rats were then randomized to receive anti-miR-21 (KD21) or scrambled control sequence (Scr21) injections into the left atrial myocardium. Progressive left ventricular enlargement, hypocontractility, left atrial dilation, fibrosis, refractoriness prolongation, and AF promotion occurred in MI rats versus sham controls. Atrial tissues of MI rats showed upregulation of miR-21, along with dysregulation of the target genes Sprouty-1, collagen-1, and collagen-3. KD21 treatment reduced atrial miR-21 expression levels in MI rats to values in sham rats, decreased AF duration from 417 (69-1595; median [Q1-Q3]) seconds to 3 (2-16) seconds (8 weeks after MI; P<0.05), and reduced atrial fibrous tissue content from 14.4 ± 1.8% (mean ± SEM) to 4.9 ± 1.2% (8 weeks after MI; P<0.05) versus Scr21 controls.</AbstractText>MI-induced heart failure leads to AF-promoting atrial remodeling in rats. Atrial miR-21 knockdown suppresses atrial fibrosis and AF promotion, implicating miR-21 as an important signaling molecule for the AF substrate and pointing to miR-21 as a potential target for molecular interventions designed to prevent AF.</AbstractText> |
13,837 | Reasons for loss of cardiac resynchronization therapy pacing: insights from 32 844 patients. | The efficacy of cardiac resynchronization therapy (CRT) is associated with the amount of CRT pacing delivered. The specific causes of CRT pacing loss and their relative frequencies remain poorly defined.</AbstractText>CRT patients who transmitted device data from 2006 to 2011 were screened for inclusion. Device diagnostics were analyzed using an automated algorithm to categorize CRT loss into 10 different causes. The algorithm was validated against manual adjudications using a portion of the entire cohort. There were 80 768 patients analyzed with a median time of 594 (interquartile range, 294-1003) days from implant to time of analysis. In this cohort, 40.7% of patients had <98% pacing, and 11.5% of patients had <90% pacing. For patients with <98% pacing, device diagnostics explained 55.8% of pacing loss: 30.6% atrial tachycardia/atrial fibrillation; 16.6% premature ventricular contractions; and 8.6% captured as episodes with at least 10 consecutive beats of CRT loss (ventricular sensing episodes). Inappropriately programmed sensed and paced atrioventricular (AV) intervals (SAV/PAV) accounted for 34.5% of all ventricular sensing episodes. As the severity of CRT loss increased, the contribution of atrial tachycardia/atrial fibrillation and SAV/PAV to the loss increased. Atrial tachycardia/atrial fibrillation accounted for >50% and premature ventricular contractions accounted for <10% of CRT loss in those with <90% CRT pacing.</AbstractText>CRT pacing <98% was observed in 40.7% of patients. Among those with suboptimal pacing, atrial tachycardia/atrial fibrillation was the most common reason for CRT pacing loss. Inappropriately programmed SAV/PAV intervals was the most common reason for episodes of sustained loss of CRT pacing. This information can help in defining more effective treatments to improve CRT delivery.</AbstractText> |
13,838 | Docosahexaenoic acid, but not eicosapentaenoic acid, supplementation reduces vulnerability to atrial fibrillation. | The potential health benefits of ω-3 polyunsaturated fatty acids (PUFAs) usually are studied using a combination of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). This combination reduces vulnerability to experimentally induced atrial fibrillation (AF). It is unknown whether EPA and DHA have differential effects when taken alone. Using a model of pacing-induced atrial hemodynamic overload, we investigated the individual effects of EPA and DHA on vulnerability to AF and atrial remodeling.</AbstractText>Thirty-four dogs were randomized into 3 groups, all of which underwent simultaneous atrial and ventricular pacing at 220 beats per minute for 14 days. One group received purified DHA (≈1 g/d) orally for 21 days beginning 7 days before pacing began. Similarly, 1 group received ≈1 g/d purified EPA. In a third (control) group (No-PUFAs), 8 dogs received ≈1 g/d olive oil, and 12 were unsupplemented. Electrophysiological and echocardiographic measurements were taken at baseline and 21 days. Atrial tissue samples were collected at 21 days for histological and molecular analyses. Persistent AF inducibility was significantly reduced by DHA compared with No-PUFAs median [25-75 percentiles], 0% [0%-3%] for DHA versus 3.1% [2.2%-11%] for No-PUFAs; P=0.007) but not by EPA (3.4% [1.9%-8.9%]). DHA also reduced atrial fibrosis compared with No-PUFAs (11 ± 6% versus 20 ± 4%, respectively; P<0.05), whereas EPA did not (15 ± 5%; P>0.05).</AbstractText>DHA is more effective than EPA in attenuating AF vulnerability and atrial remodeling in structural remodeling-induced AF.</AbstractText> |
13,839 | Treatment of obstructive sleep apnea in patients with cardiac arrhythmias. | Obstructive sleep apnea (OSA) is the most common form of sleep-disordered breathing that is prevalent in the population and frequently under diagnosed. Usually presenting with respiratory symptoms, the most significant consequences of OSA are cardiovascular, including arrhythmias. The pathophysiology of OSA through multiple mechanisms may promote bradyarrhythmias, atrial fibrillation, premature ventricular complexes, ventricular arrhythmias, and sudden death. These mechanisms may acutely trigger nocturnal arrhythmias and may chronically affect electrical and structural myocardial changes, causing arrhythmias. Numerous epidemiological data have identified an increased risk for atrial fibrillation, ventricular fibrillation and sudden death in subjects with OSA. Diagnosis of OSA should be considered in patients with arrhythmias. However, not all patients with arrhythmias need to undergo formal testing for sleep apnea. Patients who are observed to have nocturnal arrhythmias should be considered for evaluation for possible OSA. Also, if the arrhythmia is refractory to standard therapy and if other clinical indicators of OSA are also present, there should be a low threshold for pursuing the diagnosis of sleep apnea. The principal therapy for OSA is continuous positive airway pressure (CPAP). Currently, there are limited data to support the efficacy of CPAP for arrhythmia prevention or treatment. Randomized trials are necessary to determine the efficacy of OSA treatment on arrhythmia prevention. |
13,840 | Multivisceral sarcoidosis: an unexpected finding in a water-related death. | Upon encountering a body submerged within or in close association with a watery environment, the temptation by the first responder may be to surmise that the death is probably an accidental drowning of some sort. The challenge, however, is to quickly move beyond such temptation, maintaining an open mind to other possibilities. Unearthing the circumstances surrounding a water-related death requires the collaborative efforts of groups of trained professionals including law enforcement officers, medicolegal death scene investigators, forensic scientists, and forensic pathologists. The forensic pathologist has the ultimate responsibility for the interpretation of all results arising from comprehensive autopsy and toxicological and other ancillary examinations within the context of all available investigative information, for the most accurate determination of cause and manner of death.A water-related death is presented in which investigation into the circumstances surrounding the death and ultimately comprehensive postmortem analysis lead to the discovery of multiorgan sarcoidosis and lack of supportive evidence of drowning. This in turn facilitated the proper classification of the manner of death as natural. |
13,841 | Factors influencing the decision to ICD implantation in survivors of OHCA and its influence on long term survival. | Knowledge is insufficient of the long-term benefit of an implantable cardioverter defibrillator (ICD) after out of hospital cardiac arrest (OHCA).</AbstractText>To describe the use and factors of importance for outcome in relation to ICD use among survivors of ventricular fibrillation (VF).</AbstractText>In consecutive patients discharged alive after OHCA in Gothenburg between 1988 and 2008 the long-term prognosis was followed.</AbstractText>In all, there were 5443 OHCAs of which 1489 (27%) were hospitalized alive. Of those, 495 (33%) were discharged alive, of which 390 (79%) had shockable rhythm. The use of ICDs increased, but only 58 of 390 (15%) had an ICD. Among patients who received an ICD, the 2-year mortality was 2%, versus 25% of those who did not (p<0.0001). In follow-up (mean 5.5 years; maximum 10 years), the use of an ICD showed a borderline association with mortality (adjusted hazard ratio 0.49; 95% confidence interval, 024-1.01; p=0.052). Patients who had ICD were younger and had better cerebral function compared with patients without. Predictors for mortality were cerebral function at discharge, age, history of heart failure and myocardial infarction and no coronary angiography during hospitalization.</AbstractText>Among survivors of OHCA caused by VT/VF who had ICD during hospitalization only 2% died during the subsequent 2 years. The use of ICDs was low but increasing. Factors of importance for mortality were cerebral function at the time of discharge, age, history of heart failure and myocardial infarction and no coronary angiography during hospitalization.</AbstractText>Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
13,842 | Interatrial blocks. A separate entity from left atrial enlargement: a consensus report. | Impaired interatrial conduction or interatrial block is well documented but is not described as an individual electrocardiographic (ECG) pattern in most of ECG books, although the term atrial abnormalities to encompass both concepts, left atrial enlargement (LAE) and interatrial block, has been coined. In fact, LAE and interatrial block are often associated, similarly to what happens with ventricular enlargement and ventricular block. The interatrial blocks, that is, the presence of delay of conduction between the right and left atria, are the most frequent atrial blocks. These may be of first degree (P-wave duration >120 milliseconds), third degree (longer P wave with biphasic [±] morphology in inferior leads), and second degree when these patterns appear transiently in the same ECG recording (atrial aberrancy). There are evidences that these electrocardiographic P-wave patterns are due to a block because they may (a) appear transiently, (b) be without associated atrial enlargement, and (c) may be reproduced experimentally. The presence of interatrial blocks may be seen in the absence of atrial enlargement but often are present in case of LAE. The most important clinical implications of interatrial block are the following: (a) the first degree interatrial blocks are very common, and their relation with atrial fibrillation and an increased risk for global and cardiovascular mortality has been demonstrated; (b) the third degree interatrial blocks are less frequent but are strong markers of LAE and paroxysmal supraventricular tachyarrhythmias. Their presence has been considered a true arrhythmological syndrome. |
13,843 | Current electrocardiographic criteria for diagnosis of Brugada pattern: a consensus report. | Brugada syndrome is an inherited heart disease without structural abnormalities that is thought to arise as a result of accelerated inactivation of Na channels and predominance of transient outward K current (I(to)) to generate a voltage gradient in the right ventricular layers. This gradient triggers ventricular tachycardia/ventricular fibrillation possibly through a phase 2 reentrant mechanism. The Brugada electrocardiographic (ECG) pattern, which can be dynamic and is sometimes concealed, being only recorded in upper precordial leads, is the hallmark of Brugada syndrome. Because of limitations of previous consensus documents describing the Brugada ECG pattern, especially in relation to the differences between types 2 and 3, a new consensus report to establish a set of new ECG criteria with higher accuracy has been considered necessary. In the new ECG criteria, only 2 ECG patterns are considered: pattern 1 identical to classic type 1 of other consensus (coved pattern) and pattern 2 that joins patterns 2 and 3 of previous consensus (saddle-back pattern). This consensus document describes the most important characteristics of 2 patterns and also the key points of differential diagnosis with different conditions that lead to Brugada-like pattern in the right precordial leads, especially right bundle-branch block, athletes, pectus excavatum, and arrhythmogenic right ventricular dysplasia/cardiomyopathy. Also discussed is the concept of Brugada phenocopies that are ECG patterns characteristic of Brugada pattern that may appear and disappear in relation with multiple causes but are not related with Brugada syndrome. |
13,844 | Novel anti-arrhythmic medications in the treatment of atrial fibrillation. | Atrial fibrillation (AF) is a prevalent condition particularly amongst the elderly, which contributes to both morbidity and mortality. The burden of disease has lead to significant increases in health care utilization and cost in recent years. Treatment of Atrial fibrillation consists of either a rate or rhythm control strategy. Rhythm control is achieved using medical management and/or catheter ablation. In spite of major strides in catheter ablation, this procedure remains a second line treatment of AF. Anti-arrhythmic medications represent the main treatment modality for the maintenance of sinus rhythm. Amiodarone has been used for decades because of its efficacy and lack of pro-arrhythmia despite numerous extracardiac side effects. Novel agents such as Dronedarone were designed to emulate Amiodarone without the extra-cardiac side effects. Unfortunately recent trials have raised concerns for the safety of this medication in certain patients. Other agents such as Vernakalant and Ranolazine are in development that promise to be more atrial selective in their action, thereby potentially avoiding pro-arrhythmia and heart failure side effects. It remains to be seen however if one or more of these agents achieves the required high efficacy and safety threshold. This review summarizes the main anti-arrhythmic clinical trials, early phase trials involving novel agents and examines the conflicting data relating to Dronedarone. |
13,845 | Obesity, diabetes and atrial fibrillation; epidemiology, mechanisms and interventions. | The last few decades have witnessed a global rise in adult obesity of epidemic proportions. The potential impact of this is emphasized when one considers that body mass index (BMI) is a powerful predictor of death, type 2 diabetes (T2DM) and cardiovascular (CV) morbidity and mortality [1, 2]. Similarly we have witnessed a parallel rise in the incidence of atrial fibrillation (AF), the commonest sustained cardiac arrhythmia, which is also a significant cause of cardiovascular morbidity and mortality. Part of this increase is attributable to advances in the treatment of coronary heart disease (CHD) and heart failure (HF) improving life expectancy and consequently the prevalence of AF. However, epidemiological studies have demonstrated an independent association between obesity and AF, possibly reflecting common pathophysiology and risk factors for both conditions. Indeed, weight gain and obesity are associated with structural and functional changes of the cardiovascular system including left atrial and ventricular remodeling, haemodynamic alterations, autonomic dysfunction, and diastolic dysfunction. Moreover, diabetic cardiomyopathy is characterized by an adverse structural and functional cardiac phenotype which may predispose to the development of AF [3]. In this review, we discuss the pathophysiological and mechanistic relationships between obesity, diabetes and AF, and the challenges posed in the management of this high-risk group of individuals. |
13,846 | Safety and efficacy of an ultrashort-acting β1-blocker on left ventricular dysfunction. | Landiolol hydrochloride, an ultrashort-acting β1-selective blocker, is a highly regulated drug. This study evaluated the safety and efficacy of this drug for cases of coronary artery bypass grafting (CABG) with left ventricular dysfunction. Between September 2006 and August 2009, 32 patients with a left ventricular ejection fraction of <40% underwent CABG. Two groups of patients, a group administered landiolol hydrochloride and a control group not administered this drug, were compared. The administration of landiolol hydrochloride was initiated at 1 μg/kg per minute (γ) after cardiopulmonary bypass in on-pump cases and after completion of all the distal anastomoses in off-pump cases. We observed no significant differences between the groups with respect to preoperative patient background or incidences of complications, except for postoperative atrial fibrillation. The heart rate decreased significantly 30 minutes after landiolol hydrochloride administration, but no change was observed in arterial pressure. No change was observed in other parameters; the hemodynamics were stable. The occurrence of atrial fibrillation during the intensive care unit stay (during landiolol hydrochloride administration) was significantly lower in the administration group. The difference remained significant after multiple logistic regression analysis; landiolol hydrochloride was the sole inhibitory factor. |
13,847 | Fibrosis, myocardial crossings, disconnections, abrupt turns, and epicardial reflections: do they play an actual role in human permanent atrial fibrillation? A controlled necropsy study. | Atrial myocardium fibrosis and other alterations of fiber continuity and potential circuit reentrancy (disconnections, abrupt turns, crossings, and epicardial reflections) are thought to play an important role in permanent atrial fibrillation. However, few studies have been performed in human beings. Some of them are only descriptive, and controls were usually normal hearts; thus, differences between cases and controls could be related to the underlying disease rather than the arrhythmia. We quantified by histomorphometry the above characteristics in nine samples (three from the left atrium, three from around fat pads, one from the right atrium, one from the cavum-tricuspid isthmus, and one from the ventricular septum) from 13 necropsy hearts of patients with permanent atrial fibrillation and compared the findings with those from 13 control cases with the same diseases but without any atrial arrhythmia. Statistical analysis was performed using generalized estimating equations and a normal linear mixed model for repeated measures, with significance defined as P ≤.05. No differences were found in fibrosis (estimated as collagen/(collagen+myocardium) ratio-0.26 vs. 0.23, P=.35), the presence of disconnections (70.1 vs. 61.5, P=.09), abrupt turns (43.6 vs. 45.3, P=.84), or epicardial reflections (9.4 vs. 14.5, P=.12). The only difference identified was that cases with permanent atrial fibrillation exhibited fewer crossings than those without (79.5 vs. 91.5, P=.02). In conclusion, alterations in myocardial fiber continuity, including fibrosis, seem to reflect a generalized myocardial disorganization of the atria in cardiac disease but are not specifically related to permanent atrial fibrillation. |
13,848 | Antiarrhythmic properties of ranolazine--from bench to bedside. | Pharmacological management of cardiac arrhythmias is limited by the reduced availability of safe and effective antiarrhythmic agents.</AbstractText>Ranolazine is an agent currently used for the treatment of angina, which inhibits transmembrane ionic currents involved in several phases of the action potential in both the atrial and the ventricular cells. Due to its mechanism of action, ranolazine has been shown to exhibit antiarrhythmic properties that have been validated in the experimental models. This article recapitulates the mechanism of antiarrhythmic action of ranolazine, the existing clinical data, and the ongoing relevant clinical trials.</AbstractText>The combination of the antiischemic properties of ranolazine with its antiarrhythmic potency and minimal proarrhythmia provides a promising background that could expand its therapeutic role in the management of atrial fibrillation and ventricular tachyarrhythmias. Data derived from adequately powered randomized clinical trials will determine whether the door to a new indication will open for ranolazine in the near future.</AbstractText> |
13,849 | Epilepsy is a risk factor for sudden cardiac arrest in the general population. | People with epilepsy are at increased risk for sudden death. The most prevalent cause of sudden death in the general population is sudden cardiac arrest (SCA) due to ventricular fibrillation (VF). SCA may contribute to the increased incidence of sudden death in people with epilepsy. We assessed whether the risk for SCA is increased in epilepsy by determining the risk for SCA among people with active epilepsy in a community-based study.</AbstractText>This investigation was part of the Amsterdam Resuscitation Studies (ARREST) in the Netherlands. It was designed to assess SCA risk in the general population. All SCA cases in the study area were identified and matched to controls (by age, sex, and SCA date). A diagnosis of active epilepsy was ascertained in all cases and controls. Relative risk for SCA was estimated by calculating the adjusted odds ratios using conditional logistic regression (adjustment was made for known risk factors for SCA). We identified 1019 cases of SCA with ECG-documented VF, and matched them to 2834 controls. There were 12 people with active epilepsy among cases and 12 among controls. Epilepsy was associated with a three-fold increased risk for SCA (adjusted OR 2.9 [95%CI 1.1-8.0.], p=0.034). The risk for SCA in epilepsy was particularly increased in young and females.</AbstractText>Epilepsy in the general population seems to be associated with an increased risk for SCA.</AbstractText> |
13,850 | Idiopathic ventricular fibrillation with fragmented QRS complex and J wave in resting electrocardiogram. | To describe the clinical characteristics of idiopathic ventricular fibrillation (IVF) with fragmented QRS complex (f-QRS) and J wave in resting electrocardiogram.</AbstractText>We reviewed data from 21 case subjects in our hospital who were resuscitated after cardiac arrest due to IVF and assessed the prevalence of f-QRS and J wave in resting electrocardiogram (ECG). All the case subjects were classified among three groups based on the electrocardiographic morphology: group I, both f-QRS and J wave were observed (n = 6), group II, only J wave was observed (n = 9), group III, neither f-QRS nor J wave was observed (n = 6). Population characteristics, history of syncope or sudden cardiac arrest, incidence of ventricular fibrillation (VF), and circumstance of VF were evaluated among the three groups.</AbstractText>The incidence of index events (syncope, survived cardiac arrest and VF episodes recorded in implantable cardioverter defibrillator (ICD) or pacemakers) was 13.4 ± 5.6 per-year in group I, 10.8 ± 3.9 per-year in group II, and 9.8 ± 4.2 per-year in group III. There were significant differences in incidences among the three groups, the most frequent index events were observed in group I. The hazard ratio for incidence was 3.2 (95%CI, 1.1-7.9; P = 0.01). The history and circumstance of the index events were different among the groups. In group I, all the index events occurred during sleep in early morning. In group II, four subjects suffered VF during strenuous physical activities or agitation state, two during sleep in early morning, three in usual activity. In group III, one subject suffered VF during sleep in early morning, one in agitation state, four in usual activity.</AbstractText>This study suggests that the IVF patients with the combined appearance of f-QRS and J wave in the resting ECG suffer an increased risk of VF, this subgroup of IVF patients has a unique clinical feature.</AbstractText> |
13,851 | Target-organ damage and cardiovascular complications in hypertensive Nigerian Yoruba adults: a cross-sectional study. | Hypertension is a major challenge to public health as it is frequently associated with sudden death due to the silent nature of the condition. By the time of diagnosis, some patients would have developed target-organ damage (TOD) and associated clinical conditions (ACC) due to low levels of detection, treatment and control. TOD and ACC are easy to evaluate in a primary healthcare (PHC) setting and offer valuable information for stratifying cardiovascular risks in the patient. The aim of this study was to evaluate the prevalence and correlates of TOD and established cardiovascular disease (CVD) in hypertensive Nigerian adults.</AbstractText>A cross-sectional study was conducted on 2 000 healthy Yoruba adults between 18 and 64 years who lived in a rural community in south-western Nigeria. Participants diagnosed to have hypertension were examined for TOD and ACC by the presence of electrocardiographically determined left ventricular hypertrophy (LVH), microalbuminuria or proteinuria, retinopathy, or history of myocardial infarction and stroke.</AbstractText>A total of 415 hypertensive participants were examined and of these, 179 (43.1%) had evidence of TOD and 45 (10.8%) had established CVD. TOD was associated with significantly higher systolic (SBP) and diastolic blood pressure (DBP). The prevalence of LVH was 27.9%, atrial fibrillation 16.4%, microalbuminuria 12.3%, proteinuria 15.2%, hypertensive retinopathy 2.2%, stroke 6.3%, congestive heart failure (CHF) 4.6%, ischaemic heart disease 1.7%, and peripheral vascular disease 3.6%. Compared with those with normal blood pressure (BP), the multivariate adjusted odds ratios (95% confidence interval) of developing TOD was 3.61 (0.59-8.73) for those with newly diagnosed hypertension; 4.76 (1.30-13.06) for those with BP ≥ 180/110 mmHg; and 1.85 (0.74-8.59) for those with diabetes mellitus.</AbstractText>This study provides new data on TOD and its correlates in a nationally representative sample of hypertensive adults in Nigeria. In this low-resource setting, attempts should be made to detect hypertensive patients early within the community and manage them appropriately before irreversible organ damage and complications set in. The methods used in this study are simple and adaptable at the primary healthcare level for planning prevention and intervention programmes.</AbstractText> |
13,852 | Therapeutic effects of selective atrioventricular node vagal stimulation in atrial fibrillation and heart failure. | Atrial fibrillation (AF) and heart failure (HF) frequently coexist. We have previously demonstrated that selective atrioventricular node (AVN) vagal stimulation (AVN-VS) can be used to control ventricular rate during AF. Due to withdrawal of vagal activity in HF, the therapeutic effects of AVN-VS may be compromised in the combined condition of AF and HF. Accordingly, this study was designed to evaluate the therapeutic effects of AVN-VS to control ventricular rate in AF and HF.</AbstractText>A combined model of AF and HF was created by implanting a dual chamber pacemaker in 24 dogs. A newly designed bipolar electrode was inserted into the ganglionic AVN fat pad and connected to a nerve stimulator for delivering AVN-VS. In all dogs, HF was induced by high rate ventricular pacing at 220 bpm for 4 weeks. AF was then induced and maintained by rapid atrial pacing at 600 bpm after discontinuation of ventricular pacing. These HF + AF dogs were randomized into control (n = 9) and AVN-VS (n = 15) groups. In the latter group, vagal stimulation (310 μs, 20 Hz, 3-7 mA) was delivered continuously for 6 months. Compared with the control, AVN-VS had a consistent effect on ventricular rate slowing (by >50 bpm, all P < 0.001) during the entire 6-month observation period that was associated with left ventricular functional improvement. Moreover, AVN-VS was well tolerated by the treated animals.</AbstractText>AVN-VS achieved consistent rate slowing, which was associated with improved ventricular function in a canine AF and HF model. Thus, AVN-VS may be a novel, effective therapeutic option in the combined condition of AF and HF.</AbstractText>© 2012 Wiley Periodicals, Inc.</CopyrightInformation> |
13,853 | [Cardiopulmonary resuscitation should continue as long as shockable cardiac rhythms persist]. | Initiation of cardiopulmonary resuscitation or termination of a resuscitation attempt may be challenging. We report a case with a 41-year-old man who was successfully resuscitated without significant neurological deficits despite more than 45 minutes of cardiac arrest with shockable cardiac rhythms. This case demonstrates that treatment should continue as long as shockable cardiac rhythms persist. |
13,854 | Up-regulation of myocardial connexin-43 in spontaneously hypertensive rats fed red palm oil is most likely implicated in its anti-arrhythmic effects. | The purpose of this study was to test our hypothesis that red palm oil (RPO) intake may affect abnormalities of myocardial connexin-43 (Cx43) and protein kinase Cε (PKCε) signaling, and consequently the propensity of the spontaneously hypertensive rat heart (SHR) heart to arrhythmias. SHR and Wistar-Kyoto (WKY) rats fed a standard rat chow plus red palm oil (200 µL/day) for 5 weeks were compared with untreated rats. Cytosolic but not particulate PKCε expression as well as Cx43-mRNA, total Cx43 proteins, and its phoshorylated forms were increased, and disordered localization of Cx43 was attenuated in the left ventricle of RPO-fed SHR compared with untreated rats. These alterations were associated with suppression of early post-ischemic-reperfusion-related ventricular tachycardia and electrically inducible ventricular fibrillation. However, the treatment dose of RPO caused down-regulation of myocardial Cx43, but did not alter its cell membrane distribution or overall PKCε expression in WKY rats. It was, however, associated with poor arrhythmia protection, suggesting overdosing. Results indicate that SHR benefit from RPO intake, particularly because of its apparent anti-arrhythmic effects. This protection can be, in part, attributed to the preservation of cell-to-cell communication via up-regulation of myocardial Cx43, but not with PKCε activation. |
13,855 | Echocardiography-guided biventricular pacemaker optimization: role of echo Doppler in hemodynamic assessment and improvement. | In spite of improvements in heart failure management and increasing utilization of cardiac resynchronization therapy (CRT), approximately 30-40% of CRT patients remain nonresponders and 50% or more are echocardiographic nonresponders (defined as less than 15% reduction in left ventricular end systolic volume post-CRT). Optimization guided by echocardiography has been studied as one of the methods to improve the nonresponder rate to CRT. Echo-guided biventricular (Biv) pacemaker optimization has been associated with improvement in acute cardiac hemodynamics and improvement in functional class. In this review, the authors discuss various methods to optimize Biv pacemaker by echocardiography, recent advances in pacemaker optimization and the limitations of echocardiography. The authors also demonstrate complex hemodynamic derangements in heart failure via multiple case examples highlighting the role of comprehensive echo Doppler in elucidating cardiac hemodynamics encountered in CRT nonresponders, as well as tailoring of Biv pacemaker optimization to the underlying physiologic derangement. |
13,856 | Pacing in sinus node disease to prevent atrial fibrillation. | Cardiac pacing is the only effective treatment for patients with symptomatic sinus node disease (SND). The majority of patients with SND have several risk factors associated with development of atrial fibrillation (AF) at the time of pacemaker implantation and are therefore considered a high-risk population. Patients with SND can be treated with any kind of commercially available pacemaker pacing in the atrium, the ventricle or both. Pacing in SND can therefore alter atrial and ventricular conduction and atrioventricular coupling. These mechanisms can prevent or contribute to initiation and maintenance of AF during pacing. Different pacemaker modalities and algorithms have been tested to reduce AF in patients with SND in recent decades. To prevent AF in this population, it seems to be important to mimic the optimal electromechanical function of the heart, especially to preserve an optimal atrioventricular coupling. |
13,857 | Pathological changes long after liver transplantation in a familial amyloidotic polyneuropathy patient. | Liver transplantation (LT) reportedly prolongs the survival of patients with familial amyloidotic polyneuropathy (FAP), a fatal hereditary systemic amyloidosis caused by mutant transthyretin (TTR). However, what happens in systemic tissue sites long after LT is poorly understood. In the present study, we report pathological and biochemical findings for an FAP patient who underwent LT and died from refractory ventricular fibrillation more than 16&emsp14;years after FAP onset. Our autopsy study revealed that the distributions of amyloid deposits after LT were quite different from those in FAP amyloidogenic TTR V30M patients not having had LT and seemed to be similar to those observed in senile systemic amyloidosis (SSA), a sporadic systemic amyloidosis derived from wild-type (WT) TTR. Our biochemical examination also revealed that this patient's cardiac and tongue amyloid deposits derived mostly from WT TTR. We propose that FAP patients after LT may suffer from SSA-like WT TTR amyloidosis in systemic organs. |
13,858 | Efficacy of tuned waveforms based on different membrane time constants on defibrillation thresholds: primary results from the POWER trial. | The efficacy of tuned defibrillation waveforms versus the nominal fixed-tilt waveform has been previously studied. However, the optimal membrane time constant for tuning was not known. The POWER (Pulsewidth Optimized Waveform Evaluation tRial) trial was designed to determine the optimal membrane time constant for programming "tuned" biphasic waveforms.</AbstractText>This acute, multicenter study included 121 implantable cardioverter-defibrillator/cardiac resynchronization therapy defibrillator patients who were randomized at implant to any two of the three membrane time constant waveforms (2.5, 3.5, and 4.5 ms). Fixed pulse widths were programmed using the measured high voltage shock impedance. The defibrillation threshold (DFT) estimates were obtained using a hybrid protocol starting with an upper limit of vulnerability estimate followed by a step-up/step-down ventricular fibrillation induction process.</AbstractText>DFT voltage was significantly lower using 3.5- and 4.5-ms waveforms as compared to the 2.5-ms waveform (P = 0.004 and 0.035, respectively). DFT voltage with both 3.5- and 4.5-ms waveforms was ≤ that obtained with the 2.5-ms waveform in 78.5% of the cases. The mean difference in DFT voltage using the 3.5-ms waveform and the 4.5-ms waveform was not significant (P = 0.4). However, the 3.5-ms waveform gave a lower DFT than the 4.5-ms waveform in 19 patients although the reverse was true in only nine (P = 0.02 not significant for multiple comparisons).</AbstractText>The use of a 3.5- or 4.5-ms time constant-based waveforms had lower DFTs when compared to the 2.5-ms waveform. This study suggests that the first defibrillation attempt at implantation should be with 3.5- or 4.5-ms time constant-based waveforms. The 3.5-ms-based waveform trended toward the best choice.</AbstractText>©2012, The Authors. Journal compilation ©2012 Wiley Periodicals, Inc.</CopyrightInformation> |
13,859 | Ventricular arrhythmias in patients with implanted cardioverter defibrillators. | Implantable cardioverter-defibrillators (ICDs) are highly effective in reducing mortality related to ventricular arrhythmias. However, there is considerable morbidity associated with their use, mostly related to ICD shocks. In addition, the occurrence of arrhythmias and ICD shocks in patients with heart failure is associated with an adverse prognosis. Strategies to reduce or prevent ventricular arrhythmias and shocks are a prime area of focus and development in patients with ICDs. |
13,860 | Spanish Catheter Ablation Registry. 11th official report of the Spanish Society of Cardiology Working Group on electrophysiology and arrhythmias (2011). | The findings of the 2011 Spanish Catheter Ablation Registry are presented.</AbstractText>Data were collected in two ways: retrospectively using a standardized questionnaire, and prospectively from a central database. Each participating center selected its own preferred method of data collection.</AbstractText>Sixty-six Spanish centers voluntarily contributed data to the survey. Some 9662 ablation procedures were analyzed, averaging 146 (104) per center. The three main conditions treated were atrioventricular nodal reentrant tachycardia (n=2537; 26%), typical atrial flutter (n=2205; 23%) and accessory pathways (n=1813; 19%). Atrial fibrillation was the fourth most common substrate treated (n=1535; 16%) and showed a slight increase over figures for 2010. Ventricular arrhythmia ablation has increased considerably. The overall success rate was 94%; major complications occurred in 2.2% and overall mortality was 0.04%.</AbstractText>Data from the 2011 registry show a continued increase in the number of ablations performed with a generally high success rate and few complications. The use of complex substrate ablation continues to grow.</AbstractText>Copyright © 2012 Sociedad Española de Cardiología. Published by Elsevier Espana. All rights reserved.</CopyrightInformation> |
13,861 | Echocardiography In the Prediction of Atrial Fibrillation Recurrence: A Review. | Atrial fibrillation (AF) is a very common sustained arrhythmia. Co-morbidities and age signifi cantly accelerate the progression of AF to persistent and permanent forms and the development of complications. The rate of AF recurrence is 10% in the first year after the initial diagnosis (25-50% in the first month after restoration of sinus rhythm) and about 5% per annum thereafter. Left ventricular (LV) diastolic dysfunction degree has been associated with new-onset AF and in the last few years many new parameters to evaluate diastolic function were introduced and validated, even in patients with AF. Aim of this review was to summarize echocardiographic parameters, focusing on new tools, to evaluate patients with AF and to explore the role of echocardiographic evaluation to predict recurrence of the arrhythmia. |
13,862 | Effect of Omega-3 Polyunsaturated Fatty Acid Supplementation in Patients with Atrial Fibrillation. | Atrial fibrillation (AF) is the most common sustained atrial arrhythmia conferring a higher morbidity and mortality. Despite the increasing incidence of AF; available therapies are far from perfect. Dietary fish oils, containing omega 3 fatty acids, also called polyunsaturated fatty acid [PUFA] have demonstrated beneficial electrophysiological, autonomic and anti-inflammatory effects on both atrial and ventricular tissue. Multiple clinical trials, focusing on various subsets of patients with AF, have studied the role of PUFA and their potential role in reducing the incidence of this common arrhythmia. While PUFA appears to have a beneficial effect in the primary prevention of AF in the elderly with structural heart disease, this benefit has not been universally observed. In the secondary prevention of AF, PUFA seems to have a greater impact in the reducing AF in patients with paroxysmal or persistent AF, stages of AF associated with less atrial fibrosis and negative structural remodeling. However, AF suppression has not been consistently demonstrated in clinical trials. In patients undergoing heart surgery, increasing PUFA intake has yielded mixed results in terms of AF prevention post-operatively; however, increased PUFA has been associated with a reduction in hospital stay. Therefore recommending the use of PUFA for the purpose of AF reduction remains controversial. This is in part attributable to the complexity of AF. Other conflicting variables include: heterogeneous patient populations studied; variable dosing; duration of follow-up; comorbidities; and, concomitant pharmacotherapy. This review article reviews in detail available basic and clinical research studies of fish oil in the treatment of AF, and its role in the treatment of this common disorder.</AbstractText>AF=Atrial fibrillation, CHS=Cardiovascular Health Study,CABG=Coronary artery bypass surgery, d=Day, DHA=Docosahexaenoic acid, EPA=Eicosapentaenoic acid, ERP= Effective refractory period, g=Gram, PAF= Paroxysmal atrial fibrillation, PeAF= Persistent atrial fibrillation PUFA= Polyunsaturated fatty acid.</AbstractText> |
13,863 | Microvolt T-wave alternans in short QT syndrome. | T-wave alternans (TWA) is an accepted marker of risk for malignant ventricular arrhythmias, for which prognosis value has been established in different populations. Short QT syndrome (SQTS) is a very rare primary electrical disease carrying the risk of ventricular fibrillation. TWA in SQTS has not been evaluated yet.</AbstractText>Thirteen patients with SQTS (QT = 308 ± 16 ms, QTc = 329 ± 10 ms, heart rate = 69 ± 8 beats/min) underwent microvolt TWA measurement using spectral analysis. TWA testing was performed using Heartwave II (Cambridge Heart™, Inc., Bedford, MA, USA) during bicycle exercice and classified as negative, positive, or indeterminate according to the published standards for clinical interpretation.</AbstractText>Twelve patients were male (mean age 23 ± 5 years). Five were asymptomatic, three presented with aborted sudden cardiac death, and five with unexplained syncope. Six patients belonged to two unrelated families, while familial cases of SQTS were present for two other patients. A familial history of sudden death (SD) was present for seven patients. Ventricular fibrillation was inducible in three patients. Four patients were implanted with an implantable cardioverter-defibrillator and one presented with polymorphic ventricular tachycardia during follow-up. TWA was negative in each but one patient (indeterminate). Maximal negative heart rate was 118 ± 12 beats/min. Patients with previous SD displayed significant shorter QT and higher resting heart rate compared to the remaining cases.</AbstractText>TWA testing is negative in 12 of 13 SQTS patients, even in the symptomatic or inducible ones. Measurement of TWA using conventional protocol and criteria for risk stratification in SQTS seems therefore useless.</AbstractText>©2012, The Authors. Journal compilation ©2012 Wiley Periodicals, Inc.</CopyrightInformation> |
13,864 | Impact of the preprocedural frequency of paroxysmal atrial fibrillation on the clinical outcome after catheter ablation. | Pulmonary vein antral isolation (PVAI) is a recommended treatment for symptomatic drug-refractory paroxysmal atrial fibrillation (PAF). PAF naturally progresses toward persistent AF with an increase in the frequency and duration of AF. The objective of this study was to evaluate whether the preprocedural AF frequency had an impact on the AF recurrence after PVAI in patients with symptomatic PAF.</AbstractText>A total of 362 consecutive patients (61.0 ± 9.8 years; 274 males) with drug-refractory PAF who underwent PVAI were included. The preprocedural frequency of PAF was daily, weekly, monthly, and yearly in 145 (40.1%), 112 (30.9%), 90 (24.9%), and 15 (4.1%) patients, respectively. There were no significant differences in any of the preprocedural variables between the four groups, except for the number of ineffective antiarrhythmic drugs (AADs). PVAI was successfully performed in all patients. At 12 months after the initial procedure, 63.5% of the entire group of patients were free of AF recurrences without any AADs, respectively. A Cox regression multivariate analysis of the variables including the AF frequency, age, gender, duration of AF, presence of hypertension or structural heart disease, left atrial size, left ventricular ejection fraction, and body mass index demonstrated that the AF frequency was not an independent predictor of AF recurrence after a single ablation procedure (P = 0.194).</AbstractText>This study demonstrated that the preprocedural AF frequency did not predict AF recurrence after PVAI in patients with PAF. From the clinical point of view, an additional AF classification based on the preprocedural AF frequency might not be valuable in patients undergoing PVAI.</AbstractText>©2012, The Authors. Journal compilation ©2012 Wiley Periodicals, Inc.</CopyrightInformation> |
13,865 | Cardiac resynchronization therapy in patients with permanent atrial fibrillation: results from the Resynchronization for Ambulatory Heart Failure Trial (RAFT). | Cardiac resynchronization (CRT) prolongs survival in patients with systolic heart failure and QRS prolongation. However, most trials excluded patients with permanent atrial fibrillation.</AbstractText>The Resynchronization for Ambulatory Heart Failure Trial (RAFT) randomized patients to an implantable cardioverter defibrillator (ICD) or ICD+CRT, stratified by the presence of permanent atrial fibrillation. Patients with permanent atrial fibrillation were randomized to CRT-ICD (n=114) or ICD (n=115). Patients receiving a CRT-ICD were similar to those receiving an ICD: age (71.6±7.3 versus 70.4±7.7 years), left ventricular ejection fraction (22.9±5.3% versus 22.3±5.1%), and QRS duration (151.0±23.6 versus 153.4±24.7 ms). There was no difference in the primary outcome of death or heart failure hospitalization between those assigned to CRT-ICD versus ICD (hazard ratio, 0.96; 95% CI, 0.65-1.41; P=0.82). Cardiovascular death was similar between treatment arms (hazard ratio, 0.97; 95% CI, 0.55-1.71; P=0.91); however, there was a trend for fewer heart failure hospitalizations with CRT-ICD (hazard ratio, 0.58; 95% CI, 0.38-1.01; P=0.052). The change in 6-minute hall walk duration between baseline and 12 months was not different between treatment arms (CRT-ICD: 19±84 m versus ICD: 16±76 m; P=0.88). Patients treated with CRT-ICD showed a trend for a greater improvement in Minnesota Living with Heart Failure score between baseline and 6 months (CRT-ICD: 41±21 to 31±21; ICD: 33±20 to 28±20; P=0.057).</AbstractText>Patients with permanent atrial fibrillation who are otherwise CRT candidates appear to gain minimal benefit from CRT-ICD compared with a standard ICD.</AbstractText> |
13,866 | Severe generalised rhabdomyolysis with fatal outcome associated with isotretinoin. | Isotretinoin is considered to be a safe and effective therapy in otherwise therapy-resistant acne. Elevated serum creatine phosphokinase values with or without muscle-related symptoms in isotretinoin-treated patients have been reported and interpreted as benign phenomena, lethal cases have not been described yet. We present the case of a 20-year-old male who died from severe generalised rhabdomyolysis associated with isotretinoin treatment. |
13,867 | Autonomic boundary conditions for ventricular fibrillation and their implications for a novel defibrillation technique. | The sympathetic and parasympathetic divisions of the autonomic nervous system modulate cardiac rhythm and the probability of arrhythmia occurrence. Both increased sympathetic drive and hypoxia increase the likelihood for ventricular fibrillation (VF). Vagus nerve stimulation (VNS) can protect from fatal arrhythmias via cholinergic and nitrergic action. We sought to determine boundary conditions for VF and defibrillation by autonomic manipulations accompanied or not by hypoxic changes in urethane-anesthetized rats. VF was induced with (1) vagotomy, (2) systemic high-dose (>15 mg/kg) isoproterenol, and (3) hypoxemia. When VNS (50 Hz) produced cardiac standstill, it converted every VF episode (59/59). A nitric oxide synthase inhibitor did not reduce VNS efficacy (13/14 episodes converted), but addition of atropine reduced VNS efficacy (11/27 episodes converted). VF can be induced by autonomic derangements only under constrained conditions, including sympathetic over-activation, reduced parasympathetic input, and hypoxemia. VNS can provide an alternative method to defibrillate via its cholinergic action. |
13,868 | [Antitachyarrhythmic interventions of implantable cardioverter-defibrillator in primary and secondary sudden cardiac death prevention patients]. | Antitachycardia pacing (ATP) and high voltage interventions (CV) are methods of interrupting dangerous ventricular arrhythmias. The aim of the study was to determine the frequency of ventricular tachyarrhythmias and form of ICD interventions in patients in the primary and secondary sudden cardiac death (SCD) prevention groups.</AbstractText>The study involved 399 patients (334 male, 65 female), mean age was 65.2 +/- 12.1 years (21-89 years), who had an ICD implanted in years 2008-2010. The analysis comprised age, gender, indications for ICD implantation, intracardiac electrograms derived from ICD during the follow-up.</AbstractText>The patients were divided in 2 groups depending on the SCD prevention type: group A - primary prevention, group B - secondary prevention. In the A group, the peak death rate was in the 7th decade of life, while in the B group it was 10 years later. In the A group the main condition was coronary arteries disease (CAD) (76%) and dilating non-ischemic cardiomiopathy (18%), whilst in the B group, only CAD (100%). In the A group different forms of ventricular tachyarrhythmias were registered more often in the dead (57%), than living patients (38%). The difference was statistically significant (p < 0.025) and considered mainly ventricular fibrillation observed in 21% of dead patients and only in 4,2% living. Despite the fact, that in the B group the percentage of dangerous ventricular tachyarrhythmias (VT and especially VF) was higher, there were fewer deaths than in A group (7.8 vs 12.8%). In living patients in the B group, there were registered twice as many ICD interventions as in the A group. In the A group, in patients over 70 years old, in contrary to the younger, more frequently ventricular tachyarrhythmias and antiarrhythmic interventions (ATP, CV) were observed. In the B group, the relation was reversed. Inadequate and ineffective interventions occurred mainly in the A group.</AbstractText>There were twice as many ICD interventions in patients implanted in secondary SCD prevention than in patients implanted in primary prevention. In secondary prevention, in contrary to the primary, the frequency of ventricular tachyarrhythmias and ICD interventions in patients younger than 70 years old is higher than in older patients. The most frequent reason for inadequate ICD interventions are sinus tachycardia and atrial fibrillation.</AbstractText> |
13,869 | Implantable cardioverter defibrillator with and without defibrillation threshold testing. | Defibrillation threshold (DFT) testing at the time of implantable cardioverter defibrillator (ICD) insertion is performed routinely. This practice is being reconsidered due to doubts about its ability to improve ICD efficacy and evidence that survival may not be affected by the test.</AbstractText>To compare the outcome of ICD recipients who underwent DFT testing and those who did not.</AbstractText>A total of 213 eligible patients were implanted with an ICD between 2004 and 2009. DFT testing was performed in 80 of them. We compared total mortality, appropriate and inappropriate ICD shocks, and anti-tachycardia pacing (ATP) events between DFT and non-DFT patients during a follow-up of 2 years.</AbstractText>On comparing the DFT and non-DFT groups, we found a 2 year mortality rate of 7.5% versus 8.3%, respectively (P = 0.8). Furthermore, 20.7% of patients in the DFT group and 12.4% in the non-DFT group had at least one episode of ICD shock (P = 0.15). With regard to ICD treatment (ICD shocks or ATP events), 57.7% in the DFT group and 64.2% in the non-DFT group received appropriate treatments (P = 0.78).</AbstractText>No significant differences in the incidence of 2 year mortality or percentage of ICD treatment emerged between the DFT and non-DFT groups.</AbstractText> |
13,870 | Isoprenaline and quinidine to calm Brugada VF storm. | A 3-year-old man with an implanted cardioverter-defibrillator (ICD) for type 2 Brugada syndrome was admitted to coronary care unit with ventricular fibrillation electrical storm and consequent appropriate recurrent ICD shocks. The rhythm did not settle with conventional antiarrhythmics such as β-blockers and amiodarone. An isoprenaline infusion was set up with immediate stabilisation of rhythm. After a period of monitoring, the infusion was stopped and oral quinidine was started. He has remained free of problems for 1 year. This case-report summarises these novel treatments for electrical storm in Brugada syndrome and the mechanism behind them. |
13,871 | Feasibility and efficacy of electrical cardioversion after cardiac resynchronization implantation in patients with permanent atrial fibrillation. | Patients with permanent atrial fibrillation (AF) who undergo cardiac resynchronization therapy (CRT) may spontaneously recover sinus rhythm during follow-up. We tested the feasibility and efficacy of electrical cardioversion attempted after 3 months of CRT in patients with permanent AF and measured the long-term maintenance of sinus rhythm.</AbstractText>Twenty-eight consecutive patients with permanent AF in whom CRT defibrillators had been implanted were scheduled for internal electrical cardioversion after 3 months (group A) and were compared with a control group of 27 patients (group B).</AbstractText>In group A, 22 patients (79 %) were eligible for cardioversion; sinus rhythm was restored in 18 (82 %) of these, with no procedural complications. After 12 months, 16 patients (58 %) in group A were in sinus rhythm, compared with one group B patient who spontaneously recovered sinus rhythm (4 %, p < 0.001). On 12-month evaluation, ejection fraction had improved in both groups, but a reduction in left ventricular end-systolic volume was recorded only in group A patients (p = 0.018 versus baseline).</AbstractText>In patients with permanent AF, the rhythm control strategy consisting of internal cardioversion, performed by means of the implanted cardioverter-defibrillator after 3 months of CRT, was associated with a high rate of sinus rhythm resumption on long-term follow-up and with a better echocardiographic response to CRT than that seen in patients treated according to a rate control strategy.</AbstractText> |
13,872 | Sex differences in clinical characteristics and outcomes in elderly patients with heart failure and preserved ejection fraction: the Irbesartan in Heart Failure with Preserved Ejection Fraction (I-PRESERVE) trial. | There are few sex-specific outcome data in heart failure with preserved ejection fraction.</AbstractText>We assessed sex differences in baseline characteristics and outcomes among 4128 patients with heart failure with preserved ejection fraction in the Irbesartan in Heart Failure with Preserved Ejection Fraction (I-PRESERVE) trial. Women (n=2491) with heart failure with preserved ejection fraction were ≈1 year older (72±7 years versus 71±7 years) and more likely to be obese (46% versus 35%) and have chronic kidney disease (34% versus 26%) and hypertension (91% versus 85%) than men but less likely to have an ischemic cause (19% versus 34%), atrial fibrillation (27% versus 33%), or chronic obstructive pulmonary disease (8% versus 13%) (all P<0.001). During a mean of 49.5 months, there were 881 deaths (447 in women, 434 in men; risk ratio, 0.64; 95% CI, 0.56-0.74) and 5776 hospitalizations (3239 in women, 2537 in men; risk ratio, 0.80; 95% CI, 0.76-0.84). Women had lower risk of all-cause events (deaths and hospitalizations), even after adjusting for baseline characteristics (adjusted hazards ratio, 0.81; 95% CI, 0.73-0.89). However, the sex-related difference in risk of all-cause events was modified in the presence or absence of atrial fibrillation, renal dysfunction, stable angina pectoris, or advanced New York Heart Association class symptoms.</AbstractText>In patients with typical heart failure with preserved ejection fraction, there were prominent sex differences in baseline characteristics and outcomes. Women had better overall prognosis, although the presence of 4 common baseline characteristics seemed to moderate this finding.</AbstractText> |
13,873 | Arrhythmias in Fabry cardiomyopathy. | Prior studies suggest that the incidence of ventricular arrhythmias is high in patients with Fabry cardiomyopathy. This study evaluated the incidence of significant arrhythmias in a series of patients with Fabry cardiomyopathy.</AbstractText>Arrhythmias are important causes of morbidity and mortality in Fabry Cardiomyopathy.</AbstractText>This study was a retrospective chart review of 19 patients with known Fabry cardiomyopathy. Device interrogation reports were reviewed for those who had implantable devices. Electrocardiogram, Holter monitor, and event monitors were reviewed in those who did not have implantable devices.</AbstractText>Eighteen of nineteen patients were on enzyme replacement therapy (ERT). Nine (47%) out of 19 patients had implantable devices. Implant indications included symptomatic bradycardia, nonsustained ventricular tachycardia, conduction abnormalities, palpitations, and syncope. Mean follow-up in the patients with devices was 50 ± 23 months. Two patients received implantable cardioverter-defibrillator (ICD) shocks, 1 of which was inappropriate for atrial fibrillation. Patients were paced in the atrium 71% ± 37% of the time and paced in the ventricle 49% ± 52% of the time. Four patients with devices were paced more than 95% of the time. Patients with an ICD had lower heart rates prior to ICD implant than the group that did not have devices (60 ± 10 vs 78 ± 16, P = 0.03). Of the patients without devices, only 1 had sudden cardiac death. Patients with implanted devices had higher left ventricular (LV) mass indices compared to patients without implanted devices (136 ± 40 g/m(2) vs 93 ± 19 g/m(2), P = 0.008).</AbstractText>Significant ventricular arrhythmias are uncommon in patients with Fabry cardiomyopathy on ERT, but utilization of pacing is high. Sudden cardiac death in Fabry cardiomyopathy may be related to bradycardia.</AbstractText>© 2012 Wiley Periodicals, Inc.</CopyrightInformation> |
13,874 | Atrial fibrillation ablation and heart failure. | Atrial fibrillation (AF) worsens outcome in patients with systolic heart failure and the presence of heart failure (HF) predicts a 5- to 6-fold increase in risk of AF. In addition to loss of atrial systole, AF may contribute to left ventricular (LV) systolic dysfunction due a rapid ventricular rate, irregularity of rhythm and exacerbation of mitral regurgitation due to atrial dilatation. Elimination of atrial fibrillation with catheter ablation can improve ejection fraction and reduce heart failure symptoms and appears superior to AV node ablation and bi-ventricular pacing. AF ablation can restore sinus rhythm in most patients with heart failure. Additional study is warranted to identify which patients will receive maximum benefit from aggressive rhythm control and to determine efficacy in patients with diastolic heart failure. |
13,875 | Hypothermia-induced spatially discordant action potential duration alternans and arrhythmogenesis in nonhibernating versus hibernating mammals. | The heart of hibernating species is resistant to lethal ventricular fibrillation (VF) induced by hypothermia. Spatially discordant (SDA) cardiac alternans is a promising predictor of VF, yet its role in the mechanism of hypothermic arrhythmogenesis in both nonhibernating and hibernating mammals remains unclear. We optically mapped the posterior epicardial surface of Langendorff-perfused hearts of winter hibernating (WH, n = 13), interbout arousal (IBA; n = 4), and summer active (SA, n = 6) ground squirrels (GSs; Spermophilus undulatus) and rabbits (n = 10). Action potential duration (APD) and conduction velocity (CV) dynamic restitution and alternans were determined at 37 to 17°C. In all animals, hypothermia induced heterogeneous APD prolongation, enhanced APD dispersion, and slowed CV. In all groups, hypothermia promoted the formation of APD alternans, which was predominantly spatially concordant in GSs and SDA in rabbits (SD of APD dispersion: 4.2 ± 0.4% vs. 2.0 ± 0.3% at 37°C and 7.5 ± 1.1% vs. 3.4 ± 0.5% at 17°C, P < 0.001 for rabbits vs. the WH group, respectively). In rabbits, hypothermia significantly increased the magnitude of SDA, which enhanced the ventricular repolarization gradient, caused conduction delays (CV: 3.2 vs. 8.2 cm/s at 17°C in rabbits vs. the WH group), conduction block, and the onset of VF (0% at 37°C vs. 60% at 17°C, P < 0.01). In contrast, no arrhythmia was observed in GS hearts at any temperature. The amplitude of CV alternans was greater in rabbits (5.2 ± 0.4% versus 4.5 ± 0.3% at 37°C and 35.3 ± 4.2% vs. 14.9 ± 1.5% at 17°C in rabbits vs. the WH group, P < 0.001 at 17°C) and correlated with the amplitude of SDA. In conclusion, the mechanism underlying SDA formation during hypothermia is likely associated with CV alternans conditioned by an enhanced dispersion of repolarization. The factors of hibernating species resistance to SDA and VF seem to be the safe and dynamically stable conduction and the low dispersion of repolarization. |
13,876 | Risk stratification in hypertrophic cardiomyopathy: time for renewal? | Systematic clinical assessment and careful monitoring of patients with hypertrophic cardiomyopathy (HCM) can be used to identify a cohort of patients that benefit from medical intervention and almost certainly improve long-term outcomes. One of the major limitations of the current approach is a lack of predictive power of individual risk factors, which means that many patients receive therapy. The aim of this review is to highlight other aspects of the disease, assessed using old and new medical technologies, that appear to provide new prognostic information. The hope for the future is that their incorporation in new risk algorithms will improve treatment for all HCM patients with the disease, irrespective of their vulnerability to adverse complications. |
13,877 | [Analysis of risk factors of postoperative hemodialysis in patients undergoing off-pump coronary artery bypass grafting]. | To investigate the risk factors of postoperative hemodialysis in patients undergoing off-pump coronary artery bypass grafting (OPCAB).</AbstractText>The perioperative data of 2379 consecutive patients undergoing OPCAB from November 2007 to February 2009 were analyzed retrospectively. Patients were divided into dialysis group and non-dialysis group according to their use of hemodialysis therapy or not.</AbstractText>Fifty-four patients experienced hemodialysis postoperatively. The incidence of hemodialysis was 2.3%, the mortality rate of dialysis group and non-dialysis group was 18.5% and 0.9% respectively. Univariate analysis showed that these factors significantly related with the postoperative dialysis:intraoperative ventricular fibrillation, emergent cardiopulmonary bypass, preoperative atrial fibrillation, intraoperative atrial fibrillation, preoperative renal dysfunction, intraoperative high-dose adrenaline usage, ventricular aneurysm, combined valvular disease, hypertension, age and numbers of grafting vessels. Multivariate logistic regression showed that intraoperative ventricular fibrillation, intraoperative high-dose adrenaline usage, hypertension, age and the numbers of grafting vessel were the risk factors of postoperative hemodialysis for patients undergoing OPCAB surgery.</AbstractText>Intraoperative ventricular fibrillation, intraoperative high-dose adrenaline usage, hypertension, age and the numbers of grafting vessels were the independent predictors of postoperative hemodialysis in patients undergoing OPCAB surgery.</AbstractText> |
13,878 | Infiltrated cardiac lipids impair myofibroblast-induced healing of the myocardial scar post-myocardial infarction. | Lipids have been detected in the ischemic myocardium of patients' post-myocardial infarction (MI). However, their effect on the cardiac healing process remains unknown. We investigated whether intramyocardial lipids affect the signaling pathways involved in the fibrotic reparative response impairing cardiac healing post-MI.</AbstractText>Pigs, fed either a high-cholesterol diet (HC) or a regular-chow (NC), were subjected to experimentally-induced acute MI (90 min mid-LAD balloon occlusion) and then, upon reperfusion (R), maintained for 21 days with the same diet regime (HC/R(+) and NC/R(+), respectively). A group of hypercholesterolemic animals were sacrificed after ischemia without reperfusion (HC/R(-)). Cardiac tissue was obtained for molecular/cellular/histological analysis. Infarct size and echocardiography were assessed.</AbstractText>At the time of acute MI, hypercholesterolemic animals showed a higher incidence of ventricular dysrhythmias. At sacrifice, intramyocardial lipids were absent in HC/R(-). HC/R(+) showed higher lipid content (ApoB, cholesteryl-ester and triglycerides) and lower expression/activity of the TGFβ/TβRII/Smad2/3 pathway (involved in scar reparative fibrosis) than NC/R(+) in the forming scar. Collagen synthesis was accordingly reduced in the scar of HC/R(+). Infarct size was 44% larger in HC/R(+) which had higher apoptosis and lower Akt/eNOS activity in the jeopardized myocardium. Systolic function was similarly deteriorated post-MI in all animals whereas no changes were detected in diastolic-related parameters. No changes were detected in systolic parameters 21 days post-MI in NC/R(+) animals. In contrast, both systolic- and diastolic-related parameters were further deteriorated in HC/R(+) animals.</AbstractText>Intramyocardial lipid accumulation impairs TGFβ/TβRII/Smad2/3 signaling altering the fibrotic reparative process of the scar resulting in larger infarcts and cardiac dysfunction.</AbstractText>Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
13,879 | Idiopathic ventricular fibrillation originating from the moderator band. | We report a case of a 59-year-old man with idiopathic ventricular fibrillation storm. Ventricular fibrillation was pause-dependent and triggered by an early-coupled right ventricular premature complex. The characteristic premature beat was mapped and successfully ablated from Purkinje fibers of the moderator band. |
13,880 | Six-year prospective audit of 'scoop and run' for chest-reopening after cardiac arrest in a cardiac surgical ward setting. | The aim of the study was to identify which cardiac surgical ward patients benefit from 'scoop and run' to the operating room for chest reopening.</AbstractText>In-hospital arrests in a cardiothoracic hospital were prospectively audited over a 6-year period. The following pieces of information were collected for every patient who was scooped to the operating room following cardiac arrest on the postoperative cardiac surgical wards: type of arrest, time since surgery, patient physiology before arrest, time to chest reopening, location of chest opening, surgical findings on reopening, time to cardiopulmonary bypass (if used) and patient outcomes.</AbstractText>arrests in intensive care unit (ICU) and operating rooms. The primary outcome measure was survival to discharge from the hospital.</AbstractText>There were 99 confirmed ward arrests in 97 cardiac surgical patients. The overall survival rates to discharge and at 1 year were 53.6% (52 of 97 patients) and 44.3% (43 of 97 patients), respectively. Twenty-one of the 97 (21.6%) patients underwent scoop and run to the operating room or ICU. Five of 12 daytime 'scoop and runs' survived to discharge, whereas none of nine survived where scoop and run was undertaken at night (P < 0.05). There was a trend towards increased survival when 'scoop and run' was undertaken following ventricular fibrillation/pulseless ventricular tachycardia arrests (P = 0.06) and in younger patients (P = 0.12) but neither achieved statistical significance. The median time out from surgery of survivors was 4 days (range 2-14 days). The median time to chest opening in survivors was 22 min. Cardiopulmonary bypass was utilized in four of five survivors. The median ICU and hospital lengths of stay were 176 h (range 34-857) and 28 days (range 13-70), respectively.</AbstractText>The key determinant of a favourable 'scoop and run' outcome was whether the arrest occurred during daytime or night-time hours (P < 0.05). Despite a median time to chest opening of 22 min, all five survivors were discharged neurologically intact. The median time from surgery in these survivors was 4 days. Because of the risk of hypoxic brain damage, 'scoop and run' should be restricted to patients suffering witnessed arrests. The study has potential implications for resuscitation training and out-of-hours medical staffing in cardiothoracic hospitals.</AbstractText> |
13,881 | Effects of pitavastatin on cardiac structure and function and on prevention of atrial fibrillation in elderly hypertensive patients: a prospective study of 2-years' follow-up. | The aim of this prospective study was to determine whether statin therapy (pitavastatin) has a beneficial effect on the prevention of new-onset atrial fibrillation (AF) in elderly patients with hypertension (HTN) and to evaluate the relationships among statin treatment, the development of AF, and left atrial (LA) and ventricular (LV) structure and function.</AbstractText>We enrolled eligible elderly patients (≥65 years old) with HTN and LV hypertrophy until the number of patients reached 110 in both groups. The 110 patients with HTN who needed statin therapy (HTN with statin group) were started on pitavastatin (1-2 mg/day), and both groups continued with appropriate medication for HTN. LV and LA structure and function were examined by conventional and speckle-tracking echocardiography at baseline and after 1 year. LA volume and function in the HTN with statin group improved more than in the HTN without statin group. There was a significant difference in survival free of new-onset AF in the patients with and without statin therapy during the 2-year follow-up (hazard ratio: 0.32, P=0.027).</AbstractText>Pitavastatin had a beneficial effect on LV diastolic function and LA structure and function in elderly patients with HTN. Pitavastatin treatment may be associated with a lower incidence of new-onset AF.</AbstractText> |
13,882 | In-hospital mortality among patients with takotsubo cardiomyopathy: a study of the National Inpatient Sample 2008 to 2009. | Takotsubo cardiomyopathy is characterized by acute, reversible left ventricular apical ballooning. Little is known about the characteristics of patients with takotsubo cardiomyopathy who have in-hospital mortality. We sought to determine in-hospital mortality rate, complication rate, and characteristics of patients with in-hospital mortality related to takotsubo cardiomyopathy.</AbstractText>Patients diagnosed with takotsubo cardiomyopathy in the National Inpatient Database Samples 2008 to 2009 using International Classification of Diseases, Ninth Revision, code 42983 were included in this study. Our primary outcome was in-hospital mortality. In patients with takotsubo cardiomyopathy, we assessed demographic factors, the prevalence and associated mortality of underlying critical illnesses (acute ischemic stroke, sepsis, acute renal failure, respiratory insufficiency, and noncardiac surgery), and acute complications (acute congestive heart failure, respiratory insufficiency with congestive heart failure, cardiogenic shock, ventricular fibrillation/cardiac arrest, and intraaortic balloon pump placement).</AbstractText>A total of 24,701 patients with takotsubo cardiomyopathy were identified. In-hospital mortality rate was 4.2%. A total of 21,994 patients (89.0%) were female. Male patients had a higher mortality rate than females (8.4% vs 3.6%, P < .0001). Age and race were not associated with mortality. Of patients with in-hospital mortality, 81.4% had underlying critical illnesses. Male patients with takotsubo had higher incidence of underlying critical illnesses than their female counterparts (36.6% vs 26.8%, P < .0001).</AbstractText>The presence of underlying critical illness was the main driver of mortality, as these patients comprised >80% of patients with in-hospital mortality. Male patients, who were significantly more likely to have underlying critical illness, had significantly higher mortality rates than female patients. The presence of underlying critical illness likely explains the higher mortality rate among male patients.</AbstractText>Copyright © 2012 Mosby, Inc. All rights reserved.</CopyrightInformation> |
13,883 | Anatomy, mechanics, and pathophysiology of the mitral annulus. | The mitral annulus plays an important role in leaflet coaptation, in unloading mitral valve closing forces, and in promoting left atrial and left ventricular filling and emptying. Perturbations of annular mechanics figure prominently in a number of disorders including functional and ischemic mitral regurgitation, mitral valve prolapse, atrial fibrillation, mitral annular calcification, and annular submitral aneurysm. This review discusses the role of annular dysfunction in the pathogenesis of these disorders. |
13,884 | Hypertrophic cardiomyopathy. | Hypertrophic cardiomyopathy is a common inherited cardiovascular disease present in one in 500 of the general population. It is caused by more than 1400 mutations in 11 or more genes encoding proteins of the cardiac sarcomere. Although hypertrophic cardiomyopathy is the most frequent cause of sudden death in young people (including trained athletes), and can lead to functional disability from heart failure and stroke, the majority of affected individuals probably remain undiagnosed and many do not experience greatly reduced life expectancy or substantial symptoms. Clinical diagnosis is based on otherwise unexplained left-ventricular hypertrophy identified by echocardiography or cardiovascular MRI. While presenting with a heterogeneous clinical profile and complex pathophysiology, effective treatment strategies are available, including implantable defibrillators to prevent sudden death, drugs and surgical myectomy (or, alternatively, alcohol septal ablation) for relief of outflow obstruction and symptoms of heart failure, and pharmacological strategies (and possibly radiofrequency ablation) to control atrial fibrillation and prevent embolic stroke. A subgroup of patients with genetic mutations but without left-ventricular hypertrophy has emerged, with unresolved natural history. Now, after more than 50 years, hypertrophic cardiomyopathy has been transformed from a rare and largely untreatable disorder to a common genetic disease with management strategies that permit realistic aspirations for restored quality of life and advanced longevity. |
13,885 | [Mathematical modeling of ventricular disturbances following atrial fibrillation]. | The present study presents the results of mathematical and computer modeling of atrial fibrillation and ventricular disturbances following atrial fibrillation. The model is based on the assumption, that electric impulsation arriving on the atrioventricular node during atrial fibrillation is sum N of independent pulse streams with various amplitude-frequency and phase characteristics. With this model it becomes possible to investigate the dependence of nonlinear dynamics of PP and RR intervals on amplitude-frequency and phase characteristics pulse streams. Results of computer experiments are compared with real physiological experiments on rabbits. Identification of model was carried out by means of least-squares procedure. |
13,886 | Influence of acute stress on cardiac electrophysiological stability in male goats. | Stress plays an important role in the pathogenesis of ventricular arrhythmias. This study was designed to examine the effect of acute stress and metoprolol, a beta adrenergic receptor blocker, on cardiac electrophysiological stability of male goats.</AbstractText>Fifteen male goats were randomly divided into three groups: (i) control animals (n=5), (ii) a compound stimuli group including noise and red flash (n=5), (iii) and a compound stimuli group with metoprolol treatment (n=5). Plasma catecholamines were determined by using high performance chromatography with electrochemical detection. Heart rate turbulence (HRT) and heart rate variability (HRV) were analysed with the MGY-H12L analysis system. Also, the ventricular fibrillation threshold (VFT) and the ventricular vulnerable period (VVP) were determined by programmed S1S2 stimulus with bipolar electrodes at the apex of the goat hearts.</AbstractText>Compound stimuli increased plasma catecholamine levels progressively and decreased the negative value of turbulence onset (TO), turbulence slope (TS), SDNN, PNN50. Moreover, compound stimuli broadened VVP and decreased VFT significantly. Although metoprolol treatment failed to affect plasma catecholamine levels, TS and PNN50 value of the compound stimuli group, it significantly increased the negative value of TO, SDNN, VFT and narrowed VVP.</AbstractText>Our data demonstrates that compound stimuli can induce acute stressful reactions, and decrease the cardiac electrophysiological stability of male goats, which can be counteracted by metoprolol treatment.</AbstractText> |
13,887 | Implantable cardioverter-defibrillators have reduced the incidence of resuscitation for out-of-hospital cardiac arrest caused by lethal arrhythmias. | Over the last decades, a gradual decrease in ventricular fibrillation (VF) as initial recorded rhythm during resuscitation for out-of-hospital cardiac arrest (OHCA) has been noted. We sought to establish the contribution of implantable cardioverter-defibrillator (ICD) therapy to this decline.</AbstractText>Using a prospective database of all OHCA resuscitation in the province North Holland in the Netherlands (Amsterdam Resuscitation Studies [ARREST]), we collected data on all patients in whom resuscitation for OHCA was attempted in 2005-2008. VF OHCA incidence (per 100 000 inhabitants per year) was compared with VF OHCA incidence data during 1995-1997, collected in a similar way. We also collected ICD interrogations of all ICD patients from North Holland and identified all appropriate ICD shocks in 2005-2008; we calculated the number of prevented VF OHCA episodes, considering that only part of the appropriate shocks would result in avoided resuscitation. VF OHCA incidence decreased from 21.1/100 000 in 1995-1997 to 17.4/100 000 in 2005-2008 (P<0.001). Non-VF OHCA increased from 12.2/100 000 to 19.4/100 000 (P<0.001). VF as presenting rhythm declined from 63% to 47%. In 2005-2008, 1972 ICD patients received 977 shocks. Of these shocks, 339 were caused by a life-threatening arrhythmia. We estimate that these 339 shocks have prevented 81 (minimum, 39; maximum, 152) cases of VF OHCA, corresponding with 33% (minimum, 16%; maximum, 63%) of the observed decline in VF OHCA incidence.</AbstractText>The incidence of VF OHCA decreased over the last 10 years in North Holland. ICD therapy explained a decrease of 1.2/100 000 inhabitants per year, corresponding with 33% of the observed decline in VF OHCA.</AbstractText> |
13,888 | Evaluation of injury criteria for the prediction of commotio cordis from lacrosse ball impacts. | Commotio Cordis (CC) is the second leading cause of mortality in youth sports. Impacts occurring directly over the left ventricle (LV) during a vulnerable period of the cardiac cycle can cause ventricular fibrillation (VF), which results in CC. In order to better understand the pathophysiology of CC, and develop a mechanical model for CC, appropriate injury criteria need to be developed. This effort consisted of impacts to seventeen juvenile porcine specimens (mass 21-45 kg). Impacts were delivered over the cardiac silhouette during the venerable period of the cardiac cycle. Four impact speeds were used: 13.4, 17.9, 22.4, and 26.8 m/s. The impactor was a lacrosse ball on an aluminum shaft instrumented with an accelerometer (mass 188 g-215 g). The impacts were recorded using high-speed video. LV pressure was measured with a catheter. Univariate binary logistic regression analyses were performed to evaluate the predictive ability of ten injury criteria. A total of 187 impacts were used in the analysis. The criteria were evaluated on their predictive ability based on Somers' D (D) and Goodman-Kruskal gamma (γ). Injury risk functions were created for all criteria using a 2-parameter Weibull distribution using survival analysis. The best criteria for predicting CC were impact force (D=0.52, and γ=0.52) force*compression (D=0.49, and γ=0.49), and impact power (D=0.49, and γ=0.49). All of these criteria proved significant in predicting the probability of CC from projectile impacts in youth sports (p<0.01). Force proved to be the most predictive of the ten criteria evaluated. |
13,889 | Coronary perivascular fibrosis is associated with impairment of coronary blood flow in patients with non-ischemic heart failure. | Although myocardial interstitial fibrosis has been considered to play a pathogenic role in chronic heart failure (HF), the role of perivascular fibrosis, another form of fibrosis, remains to be elucidated.</AbstractText>We examined 64 consecutive patients with non-ischemic HF caused by hypertrophic cardiomyopathy (HCM, n=16), hypertensive heart disease (HHD, n=11), or dilated cardiomyopathy (DCM, n=37), diagnosed by both cardiac catheterization and endomyocardial biopsy (right ventricular side of the interventricular septum) in the Tohoku University Hospital between January 2001 and April 2009. We calculated the collagen volume fraction (CVF) and perivascular fibrosis ratio (PFR) in biopsy samples and also examined Thrombolysis in Myocardial Infarction (TIMI) frame count to evaluate coronary blood flow.</AbstractText>There was no significant correlation between CVF and PFR (r(2)=0.0007). Although CVF was comparable among HCM, HHD, and DCM (1.11 ± 1.04, 1.89 ± 1.61, and 1.41 ± 1.48, respectively), PFR was significantly higher in HCM than in DCM (1.78 ± 1.09 vs. 1.23 ± 0.44, p<0.05). PFR was not correlated with cardiac function parameters, such as left ventricular (LV) ejection fraction, cardiac output, LV end-diastolic pressure, LV end-diastolic volume, aortic pressure, or pulmonary artery pressure. However, PFR was significantly correlated with coronary flow in the left anterior descending coronary artery (as evaluated by TIMI frame count) (r(2)=0.3351, p<0.0001, in all-cases combined population), but not with that in the left circumflex or right coronary artery. This correlation remained significant in a logistic regression model tested in 7 variables (body mass index, PVR, CVF, presence of hypertension, dyslipidemia, diabetes mellitus, and atrial fibrillation).</AbstractText>These results indicate that coronary perivascular fibrosis is associated with the impairment of coronary blood flow although not associated with interstitial fibrosis or cardiac function, suggesting that it can be a new therapeutic target to improve coronary microcirculation.</AbstractText>Copyright © 2012 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.</CopyrightInformation> |
13,890 | Health-related quality of life in different clinical subgroups with typical AFL who have undergone cavo-tricuspid isthmus ablation. | To evaluate changes in health-related quality of life (HRQOL) in different sub-groups of a cohort of patients with typical atrial flutter (AFL) treated with cavotricuspid isthmus (CTI) radiofrequency catheter ablation.</AbstractText>95 consecutive patients due to undergo CTI ablation were enrolled in a study involving their completion of two SF-36 HRQOL questionnaires, before ablation and at one-year follow-up.</AbstractText>88 of the initial 95 patients finished the study. Regardless of whether patients experienced atrial fibrillation (AF) during follow-up, a statistically significant improvement in HRQOL was observed, compared with pre-ablation scores and in all dimensions except Bodily Pain. However, patients without AF during follow-up had significantly higher absolute HRQOL scores in most dimensions. No differences were seen in most HRQOL dimensions, with respect to AFL type (paroxysmal, persistent) or duration, whether AFL was first-episode or recurrent, Class I-III drug dependent, sex, or presence of structural heart disease or tachycardiomyopathy. Patients with persistent AFL showed the greatest improvement in HRQOL when they also had a ventricular cycle length ≤500 ms. The combination of recurrent AFL, ventricular cycle length ≤500 ms and structural heart disease led to a significantly greater improvement in physical HRQOL dimensions than did first-episode AFL, no structural heart disease and ventricular cycle >500 ms. The only independent factor associated with a greater improvement was structural cardiopathy.</AbstractText>CTI-ablation treatment leads to a significant improvement in HRQOL in patients with typical AFL. Patients with AF during follow-up show a significantly lower HRQOL at one-year post-ablation. The only independent risk factor found to be associated with a greater improvement in the physical summary component was structural cardiopathy.</AbstractText> |
13,891 | [Anticoagulation in elderly patients with atrial fibrillation: from the guidelines to the daily medical practice]. | Atrial fibrillation (AF) is a common medical problem with increasing prevalence among the elderly. Warfarin is effective in the prevention of AF-related-stroke but is often underutilized, especially in high-risk populations, like the elderly.</AbstractText>To determine, in a group of elderly patients with AF, if those treated in-line with the clinical recommendations differ from patients who were not, regarding morbidity and mortality and also to determine independent predictors of mortality. A second objective was to verify if the CHADS2 score is a good predictor of thromboembolic risk in the elderly.</AbstractText>A total of 161 consecutive elderly patients with AF admitted in a single centre were evaluated. Clinical follow-up was available for 88.4%, with a mean duration of 9 months.</AbstractText>Mean age was 80.9 ± 6.6 years; 96.3% of the patients had permanent AF, with controlled ventricular rate in 56.4%. Previous stroke was verified in 30.4%. Only 37.3% had oral anticoagulation at hospital discharge, despite 87.6% had guideline recommendation. Cumulative mortality rate in follow-up was 48.4% and the thromboembolism rate was 8.1%. We verified that CHADS2 score was a good predictor of thromboembolic risk in this population (c-statistic=0.742). Clinical follow-up showed that patients treated according with the clinical recommendations were more likely to survive (33.33% vs 53.93%; p=0.048). Multivariate analysis showed that age >80 years, renal disease, neoplasm and neuropsychic disease as independent predictors of mortality (c-statistic=0.83).</AbstractText>A gap of 50% existed between the guideline recommendations and actual practice. The use of risk stratification scores can help guide the decision to use anticoagulation in older patients with AF. Elderly patients treated according with the clinical recommendations had a better prognosis.</AbstractText> |
13,892 | Ascending-ramp biphasic waveform has a lower defibrillation threshold and releases less troponin I than a truncated exponential biphasic waveform. | We tested the hypothesis that the shape of the shock waveform affects not only the defibrillation threshold but also the amount of cardiac damage.</AbstractText>Defibrillation thresholds were determined for 11 waveforms-3 ascending-ramp waveforms, 3 descending-ramp waveforms, 3 rectilinear first-phase biphasic waveforms, a Gurvich waveform, and a truncated exponential biphasic waveform-in 6 pigs with electrodes in the right ventricular apex and superior vena cava. The ascending, descending, and rectilinear waveforms had 4-, 8-, and 16-millisecond first phases and a 3.5-millisecond rectilinear second phase that was half the voltage of the first phase. The exponential biphasic waveform had a 60% first-phase and a 50% second-phase tilt. In a second study, we attempted to defibrillate after 10 seconds of ventricular fibrillation with a single ≈30-J shock (6 pigs successfully defibrillated with 8-millisecond ascending, 8-millisecond rectilinear, and truncated exponential biphasic waveforms). Troponin I blood levels were determined before and 2 to 10 hours after the shock. The lowest-energy defibrillation threshold was for the 8-milliseconds ascending ramp (14.6±7.3 J [mean±SD]), which was significantly less than for the truncated exponential (19.6±6.3 J). Six hours after shock, troponin I was significantly less for the ascending-ramp waveform (0.80±0.54 ng/mL) than for the truncated exponential (1.92±0.47 ng/mL) or the rectilinear waveform (1.17±0.45 ng/mL).</AbstractText>The ascending ramp has a significantly lower defibrillation threshold and at ≈30 J causes 58% less troponin I release than the truncated exponential biphasic shock. Therefore, the shock waveform affects both the defibrillation threshold and the amount of cardiac damage.</AbstractText> |
13,893 | Recommendations regarding dietary intake and caffeine and alcohol consumption in patients with cardiac arrhythmias: what do you tell your patients to do or not to do? | The etiology of arrhythmias including atrial fibrillation is multifactorial. Most arrhythmias are associated with comorbid illnesses like hypertension, diabetes, thyroid disease, or advanced age. Although it is tempting to blame a stimulant like caffeine as a trigger for arrhythmias, the literature does not support this idea. There is no real benefit to having patients with arrhythmias limit their caffeine intake. Caffeine is a vasoactive substance that also may promote the release of norepinephrine and epinephrine. However, acute ingestion of caffeine (as coffee or tea) does not cause atrial fibrillation. Even patients suffering a myocardial infarction do not have an increased incidence of ventricular or other arrhythmias after ingesting several cups of coffee. Large epidemiologic studies have also failed to find a connection between the amount of coffee/caffeine used and the development of arrhythmias. As such, it does not make sense to suggest that patients with palpitations, paroxysmal atrial fibrillation, or supraventricular tachycardia, abstain from caffeine use. Energy drinks are a new phenomenon on the beverage market, with 30-50 % of young adults and teens using them regularly. Energy drinks are loaded with caffeine, sugar, and other chemicals that can stimulate the cardiac system. There is an increasing body of mainly anecdotal case reports describing arrhythmias or even sudden death triggered by exercise plus using energy drinks. Clearly, there must be more study in this area, but it is wise to either limit or avoid their use in patients with arrhythmias. Moderate to heavy alcohol use seems to be associated with the development of atrial fibrillation. The term "holiday heart" was coined back in 1978, to describe patients who had atrial fibrillation following binge alcohol use. Thus, it is reasonable to recommend to patients with arrhythmias that they limit their alcohol use, although unfortunately this treatment will likely not completely resolve their arrhythmia. |
13,894 | Bipolar irrigated radiofrequency ablation: a therapeutic option for refractory intramural atrial and ventricular tachycardia circuits. | Irrigated radiofrequency (RF) ablation can be insufficient to eliminate intramurally located septal atrial flutter (AFL) and ventricular tachycardia (VT) circuits. Bipolar ablation between 2 ablation catheters may be considered for such circuits.</AbstractText>To evaluate the utility of bipolar irrigated ablation to terminate arrhythmias resistant to unipolar ablation.</AbstractText>In vitro: Bipolar and sequential unipolar RF ablation lesions were placed on porcine ventricular tissue in a saline bath to assess for lesion transmurality. Clinical: 3 patients with atypical septal flutter (AFL), 4 patients with septal VT, and 2 with left ventricle free-wall VT, all of whom failed sequential unipolar RF ablation, underwent bipolar RF ablation using irrigated catheters placed on either surface of the interatria/interventricular septum and left ventricle free-wall, respectively.</AbstractText>In vitro: Bipolar RF was found to be more likely to achieve transmural lesions (82% vs 33%; P = .001) and could do so in tissues with thicknesses of up to 25 mm. Clinical: All 5 AFLs (3 patients) were successfully terminated with bipolar RF. In follow-up, AFL recurred in 2 of the 3 patients and atrial fibrillation and AFL recurred in 1 of the 3. All 3 thereafter underwent repeat procedures with successful maintenance of sinus rhythm in 2 of the 3 patients (6-month follow-up). In the VT subgroup, 5 of 6 septal VTs and 2 of 3 free-wall VTs were terminated successfully during ablation. In follow-up (12 months), 2 of the 4 patients in the septal bipolar group and 1 of the 2 patients in the free-wall group remained free of VT.</AbstractText>Bipolar RF can be used to terminate arrhythmias in select patients with tachyarrhythmias.</AbstractText>Copyright © 2012 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
13,895 | Low rate of secondary prevention ICDs in the general population: multiple-year multiple-source surveillance of sudden cardiac death in the Oregon Sudden Unexpected Death Study. | Sudden cardiac death (SCD) is a large public health problem that warrants on-going evaluation in the general population. While single-year community-based studies have been performed there is a lack of studies that have extended evaluation to multiple years in the same community.</AbstractText>From the on-going Oregon Sudden Unexpected Death Study, we analyzed prospectively identified SCD cases in Multnomah County, Ore, (population ≈700,000) from February 1, 2002 to January 31, 2005. Detailed information ascertained from multiple sources (first responders, clinical records, and medical examiner) was analyzed. A total of 1,175 SCD cases were identified (61% male) with a mean age of 65 ± 18 years for men versus 70 ± 20 for women (P < 0.001). The overall incidence rate for the period was 58/100,000 residents/year. One-quarter (24.6%) was ≤ 55 years of age. The most common initial rhythm was ventricular tachycardia or fibrillation (39% of cases, survival 27%) followed by asystole (36%, survival 0.7%) and pulseless electrical activity (23%, survival 6%). Among subjects that underwent resuscitation, the rate of survival to hospital discharge was 12% and overall survival to hospital discharge irrespective of resuscitation was 8%. Of the 68 survivors, 16 (24%) received a secondary prevention ICD.</AbstractText>We report annualized SCD incidence from a multiple-year, multiple-source community-based study, with higher than expected rates of women and subjects age ≤ 55 years. The low implantation rate of secondary prevention ICDs is likely to be multifactorial, but there are potential implications for recalibration of the projected need for ICD implantation; larger and more detailed studies are warranted.</AbstractText>© 2012 Wiley Periodicals, Inc.</CopyrightInformation> |
13,896 | Use of hypothermia in the intensive care unit. | Used for over 3600 years, hypothermia, or targeted temperature management (TTM), remains an ill defined medical therapy. Currently, the strongest evidence for TTM in adults are for out-of-hospital ventricular tachycardia/ventricular fibrillation cardiac arrest, intracerebral pressure control, and normothermia in the neurocritical care population. Even in these disease processes, a number of questions exist. Data on disease specific therapeutic markers, therapeutic depth and duration, and prognostication are limited. Despite ample experimental data, clinical evidence for stroke, refractory status epilepticus, hepatic encephalopathy, and intensive care unit is only at the safety and proof-of-concept stage. This review explores the deleterious nature of fever, the theoretical role of TTM in the critically ill, and summarizes the clinical evidence for TTM in adults. |
13,897 | Wide variability in drug use in out-of-hospital cardiac arrest: a report from the resuscitation outcomes consortium. | Despite the publication and dissemination of the Advanced Cardiac Life Support guidelines, variability in the use of drugs during resuscitation from out-of-hospital cardiac arrest may exist between different Emergency Medical Services throughout North America. The purpose of this study was to characterize the use of such drugs and evaluate their relationship to cardiac arrest outcomes.</AbstractText>The Resuscitation Outcomes Consortium Registry-Cardiac Arrest collects out-of-hospital cardiac arrest data from 264 Emergency Medical Services agencies in 11 geographical locations in the U.S. and Canada. Multivariable logistic regression was used to assess the association between drug use, characteristics of the cardiac arrest and a pulse at emergency department arrival and survival to discharge. A total of 16,221 out-of-hospital cardiac arrests were attended by 74 Emergency Medical Services agencies. There was a considerable variability in the administration of amiodarone and lidocaine for the treatment of shock resistant ventricular tachycardia/ventricular fibrillation. For non-shockable rhythms, atropine use ranged from 29 to 95% and sodium bicarbonate use ranged from 0.2 to 73% across agencies in the 89% of agencies that used the drug. Epinephrine use ranged from 57 to 98% within agencies. Neither lidocaine nor amiodarone was associated with a survival benefit while there was an inverse relationship between the administration of epinephrine, atropine and sodium bicarbonate and survival to hospital discharge.</AbstractText>There is considerable variability among Emergency Medical Services agencies in their use of pharmacological therapy for out-of-hospital cardiac arrests which may be resolved by performing large randomized trials examining effects on survival.</AbstractText>Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
13,898 | Stable ventricular fibrillation in a heterotopic heart transplant recipient. | We present an unusual case of ventricular fibrillation in a conscious patient symptomatic for chest pain and shortness of breath. Almost 20 years ago he underwent heterotopic cardiac transplantation for the treatment of severe idiopathic cardiomyopathy. In the precyclosporine era, this technique was extremely useful because of the high rate of graft rejection in which the maintenance of the native heart could prevent patient death. To date, with the improvements in immunosuppressive therapy, it is generally reserved to a specific subset of conditions. A coronary angiography and a cardiac MRI confirmed the diagnosis. Six months follow-up ECG was unchanged suggesting the persistence of a double heart rhythm in the same body. |
13,899 | Incidence and severity of phlebitis in patients receiving peripherally infused amiodarone. | Nurses noted that the rate of phlebitis was high when intravenous amiodarone was infused via a peripheral site. Hospital policy recommends a central vascular catheter, but this method is often not feasible because the drug is administered in emergent situations for short periods.</AbstractText>To determine the rate and severity of phlebitis in patients given peripherally infused amiodarone.</AbstractText>The literature, policy, and procedures for administration of amiodarone were reviewed; the pharmacy was consulted; and a data collection tool was developed. The tool was pilot tested and revised, and face validation was established. Data were collected during a 6-month period. A convenience sample was used.</AbstractText>The study included a total of 12 patients. Each new infusion of intravenous amiodarone was considered a separate occurrence, for a total of 24 infusions. Various grades of phlebitis developed in 8 patients (67%). Phlebitis developed at 12 of the 24 infusion sites (50%).</AbstractText>Patients receiving peripherally infused amiodarone are at high risk for phlebitis. This complication may lead to infection, additional medical intervention, delay in treatment, and prolonged hospitalization.</AbstractText> |
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