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12,700 | Prediction of midterm performance of active-fixation leads using current of injury. | There are only limited prospective data on the clinical relevance of current of injury (COI) as a predictor of the midterm performance of active-fixation leads. This study sought to investigate whether it is possible to predict the midterm performance of active-fixation leads using COI recorded at the time of implantation.</AbstractText>One hundred fifty patients (78 men; mean age, 63 ± 19 years) who received active-fixation pacing (n = 201) and defibrillator (n = 51) leads were studied. COI was measured from the intracardiac bipolar electrogram recorded at the time of lead implantation. The study outcome was good lead performance at 6 months, defined as P wave ≥ 1.5 mV, threshold <1.5 V for atrial lead, R-wave ≥ 5 mV, and threshold <1 V for ventricular lead. A total of 102 active-fixation atrial and 150 ventricular leads were implanted. During a 6-month follow-up, invasive intervention was required for seven atrial and seven ventricular leads. In multivariate analysis, COI was the only independent predictor of good outcome for the active-fixation atrial (odds ratio [OR]: 5.67, 95% confidence interval [CI]: 2.18-14.76, P = 0.001) and ventricular leads (OR: 3.99, 95% CI: 1.08-21.26, P = 0.002). Receiver-operating characteristic analysis identified ST-segment elevation ≥2.0 mV for the atrial leads (sensitivity, 75%; specificity, 89%) and ≥10.0 mV for the ventricular leads (sensitivity, 70%; specificity, 87%) as optimal cutoffs for good midterm performance.</AbstractText>Midterm performance of active-fixation leads is predictable using COI recorded at the time of lead implantation. A ST-segment elevation ≥2.0 mV in the atrial leads and ≥10.0 mV in the ventricular leads are recommended to improve the lead performance at 6 months.</AbstractText>©2013, The Authors. Journal compilation ©2013 Wiley Periodicals, Inc.</CopyrightInformation> |
12,701 | Ventricular cycle length characteristics estimative of prolonged RR interval during atrial fibrillation. | When atrial fibrillation (AF) is incessant, imaging during a prolonged ventricular RR interval may improve image quality. It was hypothesized that long RR intervals could be predicted from preceding RR values.</AbstractText>From the PhysioNet database, electrocardiogram RR intervals were obtained from 74 persistent AF patients. An RR interval lengthened by at least 250 ms beyond the immediately preceding RR interval (termed T0 and T1, respectively) was considered prolonged. A two-parameter scatterplot was used to predict the occurrence of a prolonged interval T0. The scatterplot parameters were: (1) RR variability (RRv) estimated as the average second derivative from 10 previous pairs of RR differences, T13-T2, and (2) Tm-T1, the difference between Tm, the mean from T13 to T2, and T1. For each patient, scatterplots were constructed using preliminary data from the first hour. The ranges of parameters 1 and 2 were adjusted to maximize the proportion of prolonged RR intervals within range. These constraints were used for prediction of prolonged RR in test data collected during the second hour.</AbstractText>The mean prolonged event was 1.0 seconds in duration. Actual prolonged events were identified with a mean positive predictive value (PPV) of 80% in the test set. PPV was >80% in 36 of 74 patients. An average of 10.8 prolonged RR intervals per 60 minutes was correctly identified.</AbstractText>A method was developed to predict prolonged RR intervals using two parameters and prior statistical sampling for each patient. This or similar methodology may help improve cardiac imaging in many longstanding persistent AF patients.</AbstractText>©2013, The Authors. Journal compilation ©2013 Wiley Periodicals, Inc.</CopyrightInformation> |
12,702 | Cardiac transplant in a family pedigree of hypertrophic cardiomyopathy secondary to a mutation in the AMP gene. | The phenotype of this unique condition comprises left ventricular hypertrophy (LVH), accessory pathways, atrial arrhythmia and premature failure of the atrioventricular node. At age 11, his ECG showed marked voltage criteria for LVH but his echocardiography was negative. He declined further screening but was reassessed at 21 years of age. By this time he had developed significant LVH. He had an implantable cardioventer defibrillator (ICD) in 2001. He developed atrial flutter and fibrillation which was initially treated with medical therapy and then radiofrequency ablation.Unfortunately, his condition deteriorated. He was New York Heart Association (NYHA) class 3-4 for most of 2011 and spent the latter part of the year and most of 2012 as an in-patient. An attempt to upgrade his ICD to a cardiac resynchronisation therapy-defibrillator was unsuccessful.In March 2012 he was placed on the transplant waiting list. He received an organ in June. He is now NHYA class 1 and has returned to work part-time. |
12,703 | Conductor externalization of the RIATA implantable cardioverter defibrillator lead: a challenging lead extraction requiring laser-powered sheath. | We report the case of a 27-year-old man who received a single chamber implantable cardioverter defibrillator with a St Jude Medical Riata double coil passive lead for secondary prevention of sudden cardiac death due to idiopathic ventricular fibrillation. Subsequently, he was readmitted for lead extraction because of device infection. Fluoroscopy showed externalization of the conductors proximally to the distal coil in the absence of any signs of electrical lead failure. Successful lead extraction was achieved using a laser sheath without any complications after unsuccessful mechanical sheath because of the tenacious fibrotic adherences proximal to the distal coil and extrusion of the conductors that hindered the advancement of the sheath over the lead. Our report highlights that Riata ICD leads are prone to externalization of the conductor wires, which may render an indicated lead extraction procedure of these leads more challenging. A laser powered sheath may facilitate the procedure, especially in the presence of extensive adhesions and fibrosis. |
12,704 | Outcome after implantation of a cardioverter-defibrillator in patients with Brugada syndrome: a multicenter study-part 2. | Implantable cardioverter-defibrillator indications in Brugada syndrome remain controversial, especially in asymptomatic patients. Previous outcome data are limited by relatively small numbers of patients or short follow-up durations. We report the outcome of patients with Brugada syndrome implanted with an implantable cardioverter-defibrillator in a large multicenter registry.</AbstractText>A total of 378 patients (310 male; age, 46±13 years) with a type 1 Brugada ECG pattern implanted with an implantable cardioverter-defibrillator (31 for aborted sudden cardiac arrest, 181 for syncope, and 166 asymptomatic) were included. Fifteen patients (4%) were lost to follow-up. During a mean follow-up of 77±42 months, 7 patients (2%) died (1 as a result of an inappropriate shock), and 46 patients (12%) had appropriate device therapy (5±5 shocks per patient). Appropriate device therapy rates at 10 years were 48% for patients whose implantable cardioverter-defibrillator indication was aborted sudden cardiac arrest, 19% for those whose indication was syncope, and 12% for the patients who were asymptomatic at implantation. At 10 years, rates of inappropriate shock and lead failure were 37% and 29%, respectively. Inappropriate shock occurred in 91 patients (24%; 4±4 shocks per patient) because of lead failure (n=38), supraventricular tachycardia (n=20), T-wave oversensing (n=14), or sinus tachycardia (n=12). Importantly, introduction of remote monitoring, programming a high single ventricular fibrillation zone (>210-220 bpm), and a long detection time were associated with a reduced risk of inappropriate shock.</AbstractText>Appropriate therapies are more prevalent in symptomatic Brugada syndrome patients but are not insignificant in asymptomatic patients (1%/y). Optimal implantable cardioverter-defibrillator programming and follow-up dramatically reduce inappropriate shock. However, lead failure remains a major problem in this population.</AbstractText> |
12,705 | Preoperative cardiac evaluation by dipyridamole thallium-201 myocardial perfusion scan provides no benefit in patients with abdominal aortic aneurysm. | The purpose of the present study was to evaluate the benefits of a preoperative dipyridamole thallium-201 myocardial perfusion scan in patients undergoing abdominal aortic aneurysm (AAA) repair.</AbstractText>We retrospectively reviewed findings in a prospectively collected database of patients undergoing open or endovascular repair of AAA at the Asan Medical Center, Seoul, Korea, from January 2001 to May 2011.</AbstractText>Of 373 patients, 11 (2.9 %) had postoperative myocardial infarction (MI), whereas 24 (6.4 %), 17 (4.6 %), 24 (6.4 %), and 8 (2.1 %) were diagnosed with myocardial ischemia, atrial fibrillation, ventricular arrhythmia, and congestive heart failure, respectively. The incidence of 30-day cardiac-related mortality was 1.6 % (6 of 373 patients). The preoperative variables significantly associated with postoperative cardiac events in multivariate analysis were preoperative congestive heart failure (odds ratio [OR] 8.8, 95 % confidence interval [CI] 1.36-56.73, p = 0.022), long-acting nitrates (OR 8.1, 95 % CI 1.22-54.26, p = 0.03), and body mass index (BMI) higher than 26 (OR 3.6, 95 % CI 1.49-8.48, p = 0.004). The variables obtained from dipyridamole thallium-201 myocardial perfusion scan were not correlates of postoperative cardiac events. The sensitivity of reversible defects for postoperative cardiac events was 14 % and the specificity was 90 %. Subgroup analyses revealed that thallium defects were not significant variables in predicting postoperative cardiac events in patients with coronary artery disease (CAD) or in no-CAD patients.</AbstractText>Preoperative dipyridamole thallium-201 myocardial perfusion scans were ineffective in predicting postoperative cardiac complications in AAA patients. These results suggest that the routine use of these tests for preoperative screening of patients undergoing AAA repair may not be warranted.</AbstractText> |
12,706 | Trapped platelets activated in ischemia initiate ventricular fibrillation. | We tested the hypothesis that ischemia-induced ventricular fibrillation (VF) is facilitated by platelets, trapped regionally in the ischemic zone and activated to release arrhythmogenic secretome.</AbstractText>In a randomized study in blood-free, buffer-perfused isolated rat hearts, ischemic zone territory (34±1% of left ventricle) was selected so that ischemia evoked VF in only 42% of controls. VF incidence was increased to 91% (P<0.05) by coronary ligation-induced trapping of freshly prepared autologous platelets (infused before and during coronary ligation, with trapping confirmed by 111In-labeled platelet autoradiographic imaging). Trapping of platelet secretome prepared ex vivo, or platelet-sized fluorospheres, did not increase ischemia-induced VF incidence. Secretome alone did, however, evoke VF in 2 sham coronary-ligated hearts. Perfusion did not activate infused platelets in sham coronary-ligated hearts, whereas ligation activated trapped platelets (assessed by thromboxane release). In a separate study, trapping whole-heparinized blood mimicked the ability of trapped platelets to increase VF incidence. This effect was not prevented by >5 days oral pretreatment in vivo with clopidogrel (10 mg/kg per day) or indomethacin (2.4 mg/kg per day).</AbstractText>Platelets facilitate VF during acute ischemia independently of their ability to participate in occlusive thrombosis. Moreover, the effect is unresponsive to antiplatelet drugs commonly used. Labile secretome constituents appear to be responsible. This opens a novel avenue for antiarrhythmic drug research.</AbstractText> |
12,707 | Significance of inducible very fast ventricular tachycardia (cycle length 200-230 ms) after early reperfusion for ST-segment-elevation myocardial infarction. | Electrophysiological study (EPS) after myocardial infarction may have a role in identifying patients at risk of sudden cardiac death. It has been shown previously that inducible very fast ventricular tachycardia (VT; cycle length [CL], 200-230 ms) is predictive of arrhythmia recurrence; however, its significance early after reperfusion in ST-segment-elevation myocardial infarction is unknown.</AbstractText>Consecutive patients with ST-segment-elevation myocardial infarction treated with primary percutaneous coronary intervention with a left ventricular ejection fraction ≤40% underwent early EPS with an implantable-cardioverter defibrillator implanted for inducible VT, but not for a negative EPS. The end point was the cumulative incidence of death or first arrhythmic event (defined as resuscitated cardiac arrest or spontaneous ventricular tachyarrhythmia). A total of 1721 patients with ST-segment-elevation myocardial infarction underwent early left ventricular ejection fraction assessment (median, 4 days after myocardial infarction) with a left ventricular ejection fraction≤40% in 24%. EPS was performed in 290 eligible patients with no arrhythmia or ventricular fibrillation/flutter (CL<200 ms) induced in 203 patients (EPS negative, group 1), monomorphic VT induced in 87 patients, consisting of very fast VT in 67% (group 2; n=58), and standard VT (CL>230 ms) in 33% (group 3; n=29). Kaplan-Meier 4-year cumulative incidence of death or arrhythmia was 8.2±2.3%, 33.1±7.1%, and 37.0±10.2% in groups 1, 2, and 3, respectively (P<0.001).</AbstractText>The majority of inducible VT in patients who have been reperfused early after ST-segment-elevation myocardial infarction is very fast VT (CL, 200-230 ms). This very fast VT incurs at least a similar risk of arrhythmia or death as inducible standard VT (CL>230 ms) and a significantly higher risk than patients with a negative EPS.</AbstractText> |
12,708 | Prevalence of atrial arrhythmias in arrhythmogenic right ventricular dysplasia/cardiomyopathy. | Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) is an inherited cardiomyopathy, characterized by right ventricular dysfunction and ventricular arrhythmias. Limited information is available concerning atrial arrhythmias in ARVD/C.</AbstractText>The purpose of this study was to characterize spontaneous atrial arrhythmias in a large registry population of ARVD/C patients.</AbstractText>Patients (n = 248) from the Johns Hopkins ARVD/C registry who met the diagnostic criteria and had undertaken genotype analysis were included. Medical records of each were reviewed to ascertain incidence and characteristics of atrial arrhythmia episodes. Detailed demographic, phenotypic, and structural information was obtained from registry data.</AbstractText>Thirty-five patients with ARVD/C (14%) experienced one or more types of atrial arrhythmia during median follow-up of 5.78 (interquartile range 8.52) years. Atrial fibrillation was the most common atrial arrhythmia, occurring in 80% of ARVD/C patients with atrial arrhythmias. Patients developed atrial arrhythmias at a mean age of 43.0 ± 14.0 years. Atrial arrhythmia patients obtained a total of 22 inappropriate implantable cardioverter-defibrillator shocks during follow-up. Older age at last follow-up (P <.001) and male gender (P = .044) were associated with atrial arrhythmia development. Patients with atrial arrhythmias had a higher occurrence of death (P = .028), heart failure (P <.001), and left atrial enlargement on echocardiography (P = .004).</AbstractText>Atrial arrhythmias are common in ARVD/C and present at a younger age than in the general population. They are associated with male gender, increasing age, and left atrial enlargement. Atrial arrhythmias are clinically important as they are associated with inappropriate implantable cardioverter-defibrillator shocks and increased risk of both death and heart failure.</AbstractText>© 2013 Heart Rhythm Society. All rights reserved.</CopyrightInformation> |
12,709 | The incidence, pattern, and prognostic value of left ventricular myocardial scar by late gadolinium enhancement in patients with atrial fibrillation . | This study sought to identify the frequency, pattern, and prognostic significance of left ventricular (LV) late gadolinium enhancement (LGE) in patients with atrial fibrillation (AF).</AbstractText>There are limited data on the presence, pattern, and prognostic significance of LV myocardial fibrosis in patients with AF. LGE during cardiac magnetic resonance imaging is a marker for myocardial fibrosis.</AbstractText>A group of 664 consecutive patients without known prior myocardial infarction who were referred for radiofrequency ablation of AF were studied. Cardiac magnetic resonance imaging was requested to assess pulmonary venous anatomy.</AbstractText>Overall, 73% were men, with a mean age of 56 years and a mean LV ejection fraction of 56 ± 10%. LV LGE was found in 88 patients (13%). The endpoint was all-cause mortality, and in this cohort, 68 deaths were observed over a median follow-up period of 42 months. On univariate analysis, age (hazard ratio [HR]: 1.05; 95% confidence interval [CI]: 1.03 to 1.08; chi-square likelihood ratio [LRχ(2)]: 15.2; p = 0.0001), diabetes (HR: 2.39; 95% CI: 1.41 to 4.09; LRχ(2): 10.3; p = 0.001), a history of heart failure (HR: 1.78; 95% CI: 1.09 to 2.91; LRχ(2): 5.37; p = 0.02), left atrial dimension (HR: 1.04; 95% CI: 1.01 to 1.08; LRχ(2): 6.47; p = 0.01), presence of LGE (HR: 5.08; 95% CI: 3.08 to 8.36; LRχ(2): 28.8; p < 0.0001), and LGE extent (HR: 1.15; 95% CI: 1.10 to 1.21; LRχ(2): 35.6; p < 0.0001) provided the strongest associations with mortality. The mortality rate was 8.1% per patient-year in patients with LGE compared with 2.3% patients without LGE. In the best overall multivariate model for mortality, age and the extent of LGE were independent predictors of mortality. Indeed, each 1% increase in the extent of LGE was associated with a 15% increased risk for death.</AbstractText>In patients with AF, LV LGE is a frequent finding and is a powerful predictor of mortality.</AbstractText>Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
12,710 | Treatment of monitored out-of-hospital ventricular fibrillation and pulseless ventricular tachycardia utilising the precordial thump. | Few studies have described the value of the precordial thump (PT) as first-line treatment of monitored out-of-hospital cardiac arrest (OHCA) from ventricular fibrillation and pulseless ventricular tachycardia (VF/VT).</AbstractText>Patient data was extracted from the Victorian Ambulance Cardiac Arrest Registry (VACAR) for all OHCA witnessed by paramedics between 2003 and 2011. Adult patients who suffered a monitored VF/VT of presumed cardiac aetiology were included. Cases were excluded if the arrest occurred after arrival at hospital, or a 'do not resuscitate' directive was documented. Patients were assigned into two groups according to the use of the PT or defibrillation as first-line treatment. The study outcomes were: impact of first shock/thump on return of spontaneous circulation (ROSC), overall ROSC, and survival to hospital discharge.</AbstractText>A total of 434 cases met the eligibility criteria, of which first-line treatment involved a PT in 103 (23.7%) and immediate defibrillation in 325 (74.8%) cases. Patient characteristics did not differ significantly between groups. Seventeen patients (16.5%) observed a PT-induced rhythm change, including five cases of ROSC and 10 rhythm deteriorations. Immediate defibrillation resulted in significantly higher levels of immediate ROSC (57.8% vs. 4.9%, p<0.0001), without excess rhythm deteriorations (12.3% vs. 9.7%, p=0.48). Of the five successful PT attempts, three required defibrillation following re-arrest. Overall ROSC and survival to hospital discharge did not differ significantly between groups.</AbstractText>The PT used as first-line treatment of monitored VF/VT rarely results in ROSC, and is more often associated with rhythm deterioration.</AbstractText>Crown Copyright © 2013. Published by Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
12,711 | Three-dimensional color Doppler echocardiographic quantification of tricuspid regurgitation orifice area: comparison with conventional two-dimensional measures. | Three-dimensional (3D) color Doppler echocardiography (CDE) provides directly measured vena contracta area (VCA). However, a large comprehensive 3D color Doppler echocardiographic study with sufficiently severe tricuspid regurgitation (TR) to verify its value in determining TR severity in comparison with conventional quantitative and semiquantitative two-dimensional (2D) parameters has not been previously conducted. The aim of this study was to examine the utility and feasibility of directly measured VCA by 3D transthoracic CDE, its correlation with 2D echocardiographic measurements of TR, and its ability to determine severe TR.</AbstractText>Ninety-two patients with mild or greater TR prospectively underwent 2D and 3D transthoracic echocardiography. Two-dimensional evaluation of TR severity included the ratio of jet area to right atrial area, vena contracta width, and quantification of effective regurgitant orifice area using the flow convergence method. Full-volume breath-hold 3D color data sets of TR were obtained using a real-time 3D echocardiography system. VCA was directly measured by 3D-guided direct planimetry of the color jet. Subgroup analysis included the presence of a pacemaker, eccentricity of the TR jet, ellipticity of the orifice shape, underlying TR mechanism, and baseline rhythm.</AbstractText>Three-dimensional VCA correlated well with effective regurgitant orifice area (r = 0.62, P < .0001), moderately with vena contracta width (r = 0.42, P < .0001), and weakly with jet area/right atrial area ratio. Subgroup analysis comparing 3D VCA with 2D effective regurgitant orifice area demonstrated excellent correlation for organic TR (r = 0.86, P < .0001), regular rhythm (r = 0.78, P < .0001), and circular orifice (r = 0.72, P < .0001) but poor correlation in atrial fibrillation rhythm (r = 0.23, P = .0033). Receiver operating characteristic curve analysis for 3D VCA demonstrated good accuracy for severe TR determination.</AbstractText>Three-dimensional VCA measurement is feasible and obtainable in the majority of patients with mild or greater TR. Three-dimensional VCA measurement is also feasible in patients with atrial fibrillation but performed poorly even with <20% cycle length variation. Three-dimensional VCA has good cutoff accuracy in determining severe TR. This simple, straightforward 3D color Doppler measurement shows promise as an alternative for the quantification of TR.</AbstractText>Copyright © 2013 American Society of Echocardiography. Published by Mosby, Inc. All rights reserved.</CopyrightInformation> |
12,712 | Valve replacement surgery for older individuals with preoperative atrial fibrillation: the effect of prosthetic valve choice and surgical ablation. | Prosthetic valve type selection combined with surgical ablation during left-sided heart valve replacement in older individuals with atrial fibrillation remains controversial.</AbstractText>A total of 573 patients aged 60 years or older (median, 65; range, 60-84) who underwent left-sided valve replacement surgery in the presence of atrial fibrillation from 1990 to 2010 were evaluated for all-cause mortality during a median follow-up period of 58.0 months (interquartile range, 33.1-84.1).</AbstractText>Mechanical and bioprosthetic valves were implanted in 356 (62.1%) and 217 (37.9%) patients, respectively, and 203 patients (35.4%) underwent surgical ablation concomitantly. During the follow-up period, 166 patients died. The 5- and 10- year survival rate was 76.3% ± 2.1% and 58.4% ± 3.2%, respectively. On Cox regression analysis, age (P < .001), diabetes (P = .014), left ventricular ejection fraction (P = .010), left atrial size (P = .038), the requirement for coronary bypass (P = .015), and cardiopulmonary bypass time (P < .001) emerged as significant and independent predictors of death. In addition, surgical ablation was protective against all-cause mortality (hazard ratio, 0.63; P = .033). The improved survival observed with surgical ablation was verified by propensity score adjustment models (hazard ratio, 0.64; 95% confidence interval, 0.30-0.99; P = .046). The choice of prosthetic type, however, affected neither survival (P = .79) nor event-free survival (P = .48).</AbstractText>Long-term survival after valve replacement in older individuals with atrial fibrillation was affected by several preoperative characteristics and the performance of surgical ablation but not by the choice of prosthesis. These findings suggest that surgical atrial fibrillation ablation should always be considered for these patients, regardless of the prosthesis type used.</AbstractText>Copyright © 2014 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.</CopyrightInformation> |
12,713 | Targeted ablation at stable atrial fibrillation sources improves success over conventional ablation in high-risk patients: a substudy of the CONFIRM Trial. | Pulmonary vein (PV) isolation has disappointing results in patients with obesity, heart failure, obstructive sleep apnea (OSA) and enlarged left atria (LA), for unclear reasons. We hypothesized that these comorbidities may cause higher numbers or non-PV locations of atrial fibrillation (AF) sources, where targeted source ablation (focal impulse and rotor modulation [FIRM]) should improve the single-procedure success of ablation.</AbstractText>The Conventional Ablation of AF With or Without Focal Impulse and Rotor Modulation (CONFIRM) trial prospectively enrolled 92 patients at 107 AF ablation procedures, in whom computational mapping identified AF rotors or focal sources. Patients underwent FIRM plus conventional ablation (FIRM-guided), or conventional ablation only, and were evaluated for recurrent AF quarterly with rigourous, often implanted, monitoring. We report the n = 73 patients undergoing first ablation in whom demographic information was available (n = 52 conventional, n = 21 FIRM-guided).</AbstractText>Stable sources for AF were found in 97.1% of patients. The numbers of concurrent sources per patient (2.1 ± 1.1) rose with LA diameter (P = 0.021), lower left ventricular ejection fraction (P = 0.039), and the presence of OSA (P = 0.002) or hypomagnesemia (P = 0.017). Right atrial sources were associated with obesity (body mass index ≥ 30; P = 0.015). In patients with obesity, hypertension, OSA, and LA diameter > 40 mm, single-procedure freedom from AF was > 80% when FIRM-guided was used vs. < 50% when conventional ablation was used (all; P < 0.05).</AbstractText>Patients with "difficult to treat" AF exhibit more concurrent AF sources in more widespread biatrial distributions than other patients. These mechanisms explain the disappointing results of PV isolation, and how FIRM can identify patient-specific AF sources to enable successful ablation in this population.</AbstractText>Copyright © 2013 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
12,714 | Near-fatal myocarditis complicating typhoid fever in a traveler returning from Nepal. | We report a 27-year-old traveler who returned from Nepal suffering from typhoid fever. His disease was complicated by life-threatening myocarditis and ventricular fibrillation, a rare manifestation in travelers. |
12,715 | Drug-induced Brugada syndrome by noncardiac agents. | Drug-induced Brugada syndrome (BrS) represents a great challenge for the prescribing clinicians as well as for those involved in the development of novel pharmaceuticals and in the regulatory bodies responsible with monitoring drug safety. Apart from well-known cardiac agents (mainly Class I antiarrhythmics), an increasing number of noncardiac agents, including psychotropic and anesthetic drugs, have been shown to induce the characteristic Brugada electrocardiogram pattern predisposing to fatal ventricular arrhythmias. Up to now, both repolarization and depolarization abnormalities are thought to be related to the development of ventricular fibrillation in BrS patients. This review highlights the mechanisms and the noncardiac medical agents that unmask a genetic predisposition to BrS. |
12,716 | Late sodium current inhibition: the most promising antiarrhythmic principle in the near future? | Ranolazine has primarily been developed and so far approved as an antianginal drug. However, it also has potentially interesting and relevant antiarrhythmic properties. Its antiarrhythmic effects are mainly based on the blockade of sodium currents, in particular of the late sodium current. Experimental and clinical studies have revealed an antiarrhythmic effect of ranolazine in atrial fibrillation as chronic or "pill in the pocket" therapy. Of note, this effect was preserved in the setting of chronic heart failure. Furthermore, an antiarrhythmic effect has also been shown in experimental models of ventricular tachyarrhythmias. In addition, prevention of ventricular tachyarrhythmias has been demonstrated in patients with structural heart disease. A few late sodium current inhibitors are evaluated for antiarrhythmic properties in experimental studies. However, randomized clinical data is not yet available for these recently developed agents and larger controlled trials are necessary before recommending ranozaline as a novel antiarrhythmic drug. |
12,717 | Bispectral index as a possible early marker of cerebral hypoperfusion. | We report a case of unexplained transient ventricular fibrillation in a child with ventricular septal defect (VSD) scheduled for VSD closure. The bispectral index (BIS) values dropped within 15s of transient cardiac arrest and it showed recovery within 15 s of restoration of circulation. Monitoring BIS during surgery, especially cardiac surgeries may help identify periods of cerebral ischemia early. |
12,718 | An autopsy case of tako-tsubo cardiomyopathy presenting ventricular tachycardia after pacemaker implantation. | We herein report a rare autopsy case of tako-tsubo cardiomyopathy (TTC) presenting ventricular tachycardia after pacemaker implantation. A 69-year-old male received a dual-chamber pacemaker implantation for complete atrioventricular block. He had no chest symptoms after the operation. Three days later, he developed severe chest pain, followed by syncope. Electrocardiogram showed sustained monomorphic ventricular tachycardia. Despite the use of amiodarone and frequent electrical defibrillation, ventricular tachycardia and ventricular fibrillation were repeated incessantly. He died 24 h after the syncope. The autopsy revealed no hemopericardial effusion, or perforation of leads. There were also no obstructive lesions in the coronary arteries. Myocardial necrosis was observed in the entire circumference and the all layers of the left ventricle. Microscopically, myocardial necrosis was plurifocal and contraction band necrosis. We speculate that catecholamine cardiotoxicity caused ventricular tachycardia in this case. Further studies are needed to clarify the heterogeneity of this disease. <<b>Learning objective:</b> Tako-tsubo cardiomyopathy should be considered a potential complication of pacemaker implantation. Physicians should recognize that this disorder can occur unexpectedly during medical examination or treatment.>. |
12,719 | Combination of asystole and sinus arrest with junctional escape rhythm seen in Takotsubo cardiomyopathy: A case report. | Takotsubo cardiomyopathy (TCM) is characterized by a transient depression of contractile function of mid and/or apical segments of the left ventricle with compensatory hyperkinesis of the basal segment. It leads to ballooning of the apex in systole, resembling an octopus trap, hence the name. There have been many different arrhythmias associated with TCM. These occurrences are not benign, with atrial fibrillation, atrio-ventricular block, and ventricular fibrillation most commonly associated with inpatient mortality in that order. Here we present a unique case of TCM with respect to arrhythmia. After a literature review, this is the only case to our knowledge with the rare combination of asystole and sinus arrest with junctional escape rhythm during the patient's initial presentation. <<b>Learning objective:</b> (i) Observe a case with a unique combination of arrhythmias in Takotsubo cardiomyopathy (TCM) never previously documented in the literature. (ii) Review the incidence of TCM and associated arrhythmia with inpatient mortality. (iii) Review the incidence of junctional escape rhythm associated with TCM.>. |
12,720 | Cognitive impairment after appropriate implantable cardioverter-defibrillator therapy for ventricular fibrillation. | Short periods of cerebral ischaemia during ventricular defibrillation testing may be associated with neuropsychological impairment. However, the impact of out-of-hospital ventricular fibrillation (VF) converted by implantable cardioverter-defibrillator (ICD) shock on cognitive functioning is unknown.</AbstractText>To assess the impact of out-of-hospital VF converted by ICD shock on cognitive functioning.</AbstractText>The study included 52 primary prevention ICD recipients. Patients with a history of stroke or other neurological impairment, previous head injury and individuals unable to see or speak to complete neuropsychological tests were not included.Initially, a Mini-Mental State Examination was performed in all patients and one patient with a result below 24 points was excluded from the study. The cognitive battery consisted of four tests (six measurements): 1) the Digit Span subtest of Wechsler Adult Intelligence Scale-Revised; 2) the Digit Symbol subtest of Wechsler Adult Intelligence Scale-Revised; 3) the Halstead-Reitan Trail-Making Test A and B; and 4) the Ruff Figural Fluency Test.</AbstractText>The mean time from ICD implantation to cognitive assessment was 26 months. During this period, 15 appropriate shocks for VF were observed in seven (14%) patients. The patients with appropriate ICD therapy were significantly worse in two out of the six neuropsychological measurements and had a significantly lower aggregate result. In multivariate linear regression analysis, defibrillation therapy was an independent factor of poor cognitive functioning, along with age and education.</AbstractText>Short periods of out-of-hospital VF converted by ICD are associated with cognitive impairment in the recipients of primary prevention ICD.</AbstractText> |
12,721 | Impact of pulmonary vein isolation on obstructive sleep apnea in patients with atrial fibrillation. | Obstructive sleep apnea (OSA) has been identified as associated with the onset and propagation of atrial fibrillation (AF) and predicts recurrences of AF after pulmonary vein isolation (PVI). Vice versa, it has never been investigated whether PVI influences OSA. However, it has been controversial whether a restored atrial function can affect the course of OSA. There-fore, we have assessed whether PVI procedure modulates the prevalence and severity of OSA.</AbstractText>We included 23 individuals with AF that were assigned to undergo PVI into this study. Patients were 65 ± 7 years old, obese (BMI 29.9 ± 5.4 kg/m²), white (100%) and had a normal left ventricular function (LVEF 64 ± 9%). Polygraphic assessment was carried out before and 6 months after PVI. The prevalence of OSA, defined as an apnea-hypopnea index (AHI) ≥ 5 per hour of sleep, was 74% before PVI compared to 70% 6 months after the procedure (p > 0.05). Severity of OSA did not differ (AHI before vs. after: 18 ± 18/h vs. 15 ± 17/h, p > 0.05) as well as further polygraphic parameters did not differ before and after the procedure.</AbstractText>Prevalence and severity of OSA are not affected by PVI in patients suffering from AF.</AbstractText> |
12,722 | Electromechanical delay detected by tissue Doppler echocardiography is associated with the frequency of attacks in patients with lone atrial fibrillation. | Our main purpose in this study is to compare atrial (inter-atrial, intra-left atrial, intra-right atrial) electromechanical delays of patients with lone atrial fibrillation (LAF) with healthy individuals and examine the relationship of annual LAF attack frequency.</AbstractText>32 entirely healthy individuals and 32 patients who have presented with tachycardia and complying with LAF criteria have been included in the study. The time passing from the beginning of the P wave on electrocardiography to the A' wave on tissue Doppler trace was accepted as the atrial conduction time (PA'). The PA' time difference between the mitral annulus of left ventricle (ML) and the tricuspid annulus of right ventricle (TL) was defined as inter-atrial electromechanical delay (IA-EMD), the PA' time difference between the ML and septal mitral annulus (MS) as intra-left electromechanical delay (ILeft-EMD), the PA' time difference between MS and the TL as intra-right electromechanical delay (IRight-EMD).</AbstractText>ILeft-EMD (21.8 ± 9.1 vs. 14.1 ± 4.9, p < 0.001), IRight-EMD (9.3 ± 6.8 vs. 5.9 ± 4.9, p = 0.03) and IA-EMD times (24.7 ± 11.2 vs. 11.9 ± 7.1, p < 0.001) were significantly longer in LAF patients. In multivariate regression analysis, using a model including age, gender and left atrium (LA) volumes, ILeft-EMD times (OR 1.14, 95% CI 1.03-1.27,p = 0.012), IA-EMD times (OR 1.12, 95% CI 1.03-1.23, p = 0.007) and LA volumes (OR 1.18, 95% CI 1.05-1.32, p = 0.005) were independent predictors of LAF. In LAF group, the frequency of AF episodes was significantly correlated with ILeft-EMD (r = 0.90, p < 0.001) and IA-EMD times (r = 0.36, p < 0.004), whereas, IRight-EMD times and LA volumes were not correlated with recurrence rates.</AbstractText>ILeft-EMD and IA-EMD may increase in the early stages of atrial fibrillation even without the left atrial dilation and may be more valuable than left atrial area and volume in predicting atrial fibrillation.</AbstractText> |
12,723 | Beta-blockade and A1-adenosine receptor agonist effects on atrial fibrillatory rate and atrioventricular conduction in patients with atrial fibrillation. | Reduced irregularity of RR intervals in permanent atrial fibrillation (AF) has been associated with poor outcome. It is not fully understood, however, whether modification of atrioventricular (AV) conduction using rate-control drugs affects RR variability and irregularity measures. We aimed at assessing whether atrial fibrillatory rate (AFR) and variability and irregularity of the ventricular rate are modified by a selective A1-adenosine receptor agonist tecadenoson, beta-blocker esmolol, and their combination.</AbstractText>Twenty-one patients (age 58 ± 7 years, 13 men) with AF were randomly assigned to either 75, 150, or 300 μg intravenous tecadenoson. Tecadenoson was administered alone (Dose Period 1) and in combination (Dose Period 2) with esmolol (100 μg/kg/min for 10 min then 50 μg/kg/min for 50 min). Heart rate (HR) and AFR were estimated for every 10 min long recording segment. Similarly, for every 10 min segment, the variability of RR intervals was assessed, as standard deviation, pNN20, pNN50, pNN80, and the root of the mean squared differences of successive RR intervals, and irregularity was assessed by non-linear measures such as regularity index (R) and approximate entropy. A marked decrease in HR was observed after both tecadenoson injections, whereas almost no changes could be seen in the AFR. The variability parameters were increased after the first tecadenoson bolus injection. In contrast, the irregularity parameters did not change after tecadenoson. When esmolol was infused, all the variability parameters further increased.</AbstractText>Modification of AV node conduction can increase RR variability but does not affect regularity of RR intervals or AFR.</AbstractText> |
12,724 | Ablation of atrial fibrillation in Brugada syndrome patients with an implantable cardioverter defibrillator to prevent inappropriate shocks resulting from rapid atrial fibrillation. | Inappropriate shocks resulting from atrial tachyarrhythmias are highly problematic for patients with an implantable cardioverter defibrillator (ICD). We aimed to determine the effectiveness of catheter ablation of atrial fibrillation (AF) in preventing inappropriate shocks due to rapid AF in patients diagnosed with Brugada syndrome (BS) who were implanted with an ICD.</AbstractText>We performed AF ablation in 5 BS patients with ICDs who experienced inappropriate shocks caused by rapid paroxysmal AF and in a BS patient scheduled to determine an indication of an ICD implantation who frequently experienced rapid AF.</AbstractText>Although 2 patients underwent a 2nd ablation procedure because of AF recurrences, 5 of the 6 patients were finally free from AF after their last procedure during a median follow-up period of 43.2 months. No further inappropriate shocks caused by rapid AF occurred after the 1st ablation session in any of the patients. A patient developed a ventricular fibrillation storm during his electrophysiological study following the ablation procedure, and then was implanted with an ICD.</AbstractText>AF ablation in BS patients may be reasonable to prevent inappropriate ICD shocks resulting from rapid AF. However, ventricular extrastimuli just after the ablation had better be avoided in them.</AbstractText>© 2013.</CopyrightInformation> |
12,725 | Temporary resolution of chronic atrial fibrillation after cardiac surgery and the prolongation of ventricular repolarization. | Chronic atrial fibrillation may temporarily resolve after cardiac surgery. Prolongation of the ventricular repolarization period may be the electrophysiological background for this phenomenon.</AbstractText>The aim of the study was to assess the association between resolution of atrial fibrillation and changes in the duration of the ventricular repolarization period in patients with pre-operative chronic atrial fibrillation who underwent cardiac surgery.</AbstractText>A retrospective analysis of the medical recordings of patients with chronic atrial fibrillation who underwent cardiac surgery was performed. After exclusions the study group comprised 51 patients with chronic atrial fibrillation who underwent surgery in the Cardiac Surgery Department of Wrocław Medical University in 2008 and 2009. The 12-lead EKGs performed before and after the surgery were assessed and the QT and R-R intervals were measured. The patients were divided into Group 1, in whom atrial fibrillation persisted after the cardiac surgery, and Group 2, whose atrial fibrillation resolved after the surgery.</AbstractText>In 31 patients (60.8%) atrial fibrillation disappeared during the first 24 hours after cardiac surgery. A significant prolongation of the QT interval after the surgery was found in Group 2 that was not observed in Group 1. Multiple regression analysis revealed that QT interval duration after surgery is related to the resolution of atrial fibrillation independently from the duration of the R-R interval duration and the need for cardiac pacing.</AbstractText>Spontaneous temporary resolution of atrial fibrillation is a common finding after cardiac surgery in patients with chronic atrial fibrillation. This phenomenon is related to a prolonged QT interval, therefore it may have an electrophysiological basis rather than a hemodynamic background. Further studies are required to assess the clinical importance of the prolongation of the QT interval after cardiac surgery.</AbstractText> |
12,726 | [Effectiveness of simultaneous cardiac resynchronization therapy in surgical valvular patients with severe heart failure]. | Cardiac resynchronization therapy (CRT)has been accepted broadly as an alternative to medical treatment in managing severe heart failure patients. Despite advance in CRT, the presence of a significant valvular heart disease was currently specific exclusion criteria and a response to this therapy remains unclear. The purpose of this study was to determine the effectiveness of CRT in heart failure patients undergoing valvular operation simultaneously.</AbstractText>Between July 2010 and May 2012, 8 heart failure patients who underwent CRT in conjunction with valvular surgery were experienced. Right and left ventricular and atrial epicardial leads were implanted after completion of valvular procedures. In patients with chronic atrial fibrillation(Af),maze procedure was performed in order to eliminate Af. To evaluate the improvement of ventricular mechanical dyssynchrony, the echocardiographic assessment was repeated on admission and 1 month after the CRT implantation.</AbstractText>There was no operative death. One patient of ischemic cardiomyopathy died of sustained ventricular tachycardia 2 months after the operation. Postoperative course of severe heart failure patients was uneventful and all patients except 1 discharged on foot with improved New York Heart Association (NYHA) class. Echocardiographic parameters of dyssynchrony did not reach to statistical significance, but several parameters, left ventricular( LV)-pre-ejectionperiod( PEP) and interventricular mechanical delay (IVMD) showing time delay of cardiac contraction, tended to be improve, suggesting contribution to satisfactory postoperative course.</AbstractText>The acceptable outcome was demonstrated with our concept to recover the intraventricular and atrioventricular synchrony. Although it might be difficult to establish the patient selection criteria for concomitant CRT and valvular surgery, our strategy is considered to be a feasible procedure to improve the morbidity and mortality in patients with severe heart failure due to valvular disease.</AbstractText> |
12,727 | Complex atrial arrhythmias as first manifestation of catecholaminergic polymorphic ventricular tachycardia: an unusual course in a patient with a new mutation in ryanodine receptor type 2 gene. | Catecholaminergic polymorphic ventricular tachycardia is a rare life-threatening arrhythmogenic disorder. An association with paroxysmal atrial fibrillation and other atrial arrhythmias has been described, but in all published cases the initial manifestation of the disease was ventricular arrhythmia. This is the first report about a patient who presented with complex atrial tachycardia and sinus node dysfunction about 1 year before the typical ventricular arrhythmias were observed, leading to the diagnosis of catecholaminergic polymorphic ventricular tachycardia. In this girl, a mutation of the ryanodine receptor type 2 gene, which has not been described so far, was discovered. |
12,728 | Echocardiography in newly diagnosed atrial fibrillation patients: a systematic review and economic evaluation. | To investigate the clinical effectiveness and cost-effectiveness of transthoracic echocardiography (TTE) in all patients who are newly diagnosed with atrial fibrillation (AF).</AbstractText>Narrative synthesis reviews were conducted on the prognostic and diagnostic accuracy of TTE for, and prevalence of, pathologies in patients with AF. Databases were searched from inception. MEDLINE searches were conducted from March to August 2010, and reference lists of articles checked. There were 44 diagnostic accuracy studies, five prognostic studies, and 16 prevalence studies accepted into the review. Given the complexity of the many pathologies identified by TTE, the variety of potential changes to clinical management, and paucity of data, the model focused on changes to oral anticoagulation (OAC). The mathematical model assessed the cost-effectiveness of TTE for patients with AF who were not routinely given OAC, assuming, if left atrial abnormality was detected, that the higher risk of stroke warranted OAC; this meant that patients with a CHADS2 (cardiac failure, hypertension, age, diabetes, stroke doubled) score of 0 [dabigatran etexilate (Pradaxa, Boehringer Ingelheim)/rivaroxaban (Xarelto, Bayer Schering)] or 0/1 (warfarin) were included. A simplified approach evaluated the additional quality-adjusted life-years (QALYs) required in order for TTE to be perceived as cost-effective at a threshold of £20,000 per QALY.</AbstractText>Transthoracic echocardiography is usually performed in cardiology clinics but may be used in primary or non-specialist secondary care.</AbstractText>Patients with newly diagnosed AF.</AbstractText>Transthoracic echocardiography.</AbstractText>Prognosis, diagnostic sensitivity or specificity of TTE, prevalence of pathologies in patients with AF, cost-effectiveness and QALYs.</AbstractText>Prognostic studies indicated that TTE-diagnosed left ventricular dysfunction, increased left atrial diameter and valvular abnormality were significantly associated with an increased risk of stroke, mortality or thromboembolism. There was a high prevalence (around 25-30%) of ischaemic heart disease, valvular heart disease and heart failure in patients with AF. Diagnostic accuracy of TTE was high, with most pathologies having specificity of ≥ 0.8 and sensitivity of ≥ 0.6. The mathematical model predicted that when the CHADS2 tool is used the addition of TTE in identifying patients with left atrial abnormality appears to be cost-effective for informing some OAC decisions. In the simplified approach a threshold of 0.0033 was required for a TTE to be cost-effective.</AbstractText>When CHADS2 was used, the addition of TTE in identifying patients with left atrial abnormality was cost-effective for informing some OAC decisions. A simple analysis indicates that the number of QALYs required for TTE to be cost-effective is small, and that if benefits beyond those associated with a reduction in stroke are believed probable then TTE is likely to be cost-effective in all scenarios. Our findings suggest that further research would be useful, following up newly diagnosed patients with AF who have undergone TTE, to study treatments given as a result of TTE diagnoses and subsequent cardiovascular events. This could identify additional benefits of routine testing, beyond stroke prevention. Studies assessing the proportion of people with a CHADS2 score of 0 or 1 that have left atrial abnormality would provide better estimates of the cost-effectiveness of TTE, and allow more accurate estimates of the sensitivity and specificity of TTE for identifying left atrial abnormality in AF to be obtained.</AbstractText>PROSPERO CRD42011001354.</AbstractText>The National Institute for Health Research Health Technology Assessment programme.</AbstractText> |
12,729 | [A case of large tracheoesophageal fistula after repair of the right discending aortic arch]. | A 77-year-old woman with right aortic arch was diagnosed as aortic dissection (De Bakey IIIb) and hospitalized for conservative treatment. But, her respiratory condition deteriorated due to tracheal stenosis with aortic dissection. Surgical graft replacement of the descending aorta was performed to release tracheal stenosis. Six days after surgery, tracheoesophageal fistula (TEF) was noticed. The size of the fistula was 3 cm in diameter, located 3cm to the oral side from the carina and 23 cm from the incisors. Nineteen days after surgery, an esophageal stent was placed leading to temporary improvement of the respiratory status, but it aggravated again. Unfortunately, she died due to ventricular fibrillation 26 days after surgery. The case is extremely rare with dissection of the right aortic arch. Such a case is considered to be a high risk of TEF, and it is necessary to perform early preventive measures. |
12,730 | Caring for patients receiving therapeutic hypothermia post cardiac arrest in the intensive care unit. | Survivors of ventricular fibrillation cardiac arrest have poor and often devastating neurological outcomes despite advances in resuscitation techniques and services (Bernard et al., 2002; Collins & Samworth, 2008). In an effort to increase survival rates, improve neurological outcomes and reduce mortality for surviving patients, clinical trials have shown that a mild state of therapeutic hypothermia (32 degrees C to 34 degrees C) has been linked to improved patient outcomes post cardiac arrest (Koran, 2008; Lee & Asare, 2010). Many hospitals in Canada currently use therapeutic hypothermia (TH), but the nursing care requires advanced nursing knowledge and skills. In an effort to prepare registered nurses to care for patients receiving TH, a specially designed education program was implemented at the Rouge Valley Health System Hospital (RVHS) in Ontario. Busy nurses need flexibility in the delivery of programs in the clinical setting, and this program was designed to meet that need with a combination of self-paced modules, lectures, discussions and a return demonstration. In this article, the authors discuss the nursing care of post cardiac arrest patients receiving TH, and the design and implementation of the education program. |
12,731 | Waveform analysis-guided treatment versus a standard shock-first protocol for the treatment of out-of-hospital cardiac arrest presenting in ventricular fibrillation: results of an international randomized, controlled trial. | Ventricular fibrillation (VF) waveform properties have been shown to predict defibrillation success and outcomes among patients treated with immediate defibrillation. We postulated that a waveform analysis algorithm could be used to identify VF unlikely to respond to immediate defibrillation, allowing selective initial treatment with cardiopulmonary resuscitation in an effort to improve overall survival.</AbstractText>In a multicenter, double-blind, randomized study, out-of-hospital cardiac arrest patients in 2 urban emergency medical services systems were treated with automated external defibrillators using either a VF waveform analysis algorithm or the standard shock-first protocol. The VF waveform analysis used a predefined threshold value below which return of spontaneous circulation (ROSC) was unlikely with immediate defibrillation, allowing selective treatment with a 2-minute interval of cardiopulmonary resuscitation before initial defibrillation. The primary end point was survival to hospital discharge. Secondary end points included ROSC, sustained ROSC, and survival to hospital admission. Of 6738 patients enrolled, 987 patients with VF of primary cardiac origin were included in the primary analysis. No immediate or long-term survival benefit was noted for either treatment algorithm (ROSC, 42.5% versus 41.2%, P=0.70; sustained ROSC, 32.4% versus 33.4%, P=0.79; survival to admission, 34.1% versus 36.4%, P=0.46; survival to hospital discharge, 15.6% versus 17.2%, P=0.55, respectively).</AbstractText>Use of a waveform analysis algorithm to guide the initial treatment of out-of-hospital cardiac arrest patients presenting in VF did not improve overall survival compared with a standard shock-first protocol. Further study is recommended to examine the role of waveform analysis for the guided management of VF.</AbstractText> |
12,732 | Safety and efficacy of a totally subcutaneous implantable-cardioverter defibrillator. | The most frequent complications associated with implantable cardioverter-defibrillators (ICDs) involve the transvenous leads. A subcutaneous implantable cardioverter-defibrillator (S-ICD) has been developed as an alternative system. This study evaluated the safety and effectiveness of the S-ICD System (Cameron Health/Boston Scientific) for the treatment of life-threatening ventricular arrhythmias (ventricular tachycardia/ventricular fibrillation).</AbstractText>This prospective, nonrandomized, multicenter trial included adult patients with a standard indication for an ICD, who neither required pacing nor had documented pace-terminable ventricular tachycardia. The primary safety end point was the 180-day S-ICD System complication-free rate compared with a prespecified performance goal of 79%. The primary effectiveness end point was the induced ventricular fibrillation conversion rate compared with a prespecified performance goal of 88%, with success defined as 2 consecutive ventricular fibrillation conversions of 4 attempts. Detection and conversion of spontaneous episodes were also evaluated. Device implantation was attempted in 321 of 330 enrolled patients, and 314 patients underwent successful implantation. The cohort was followed for a mean duration of 11 months. The study population was 74% male with a mean age of 52±16 years and mean left ventricular ejection fraction of 36±16%. A previous transvenous ICD had been implanted in 13%. Both primary end points were met: The 180-day system complication-free rate was 99%, and sensitivity analysis of the acute ventricular fibrillation conversion rate was >90% in the entire cohort. There were 38 discrete spontaneous episodes of ventricular tachycardia/ventricular fibrillation recorded in 21 patients (6.7%), all of which successfully converted. Forty-one patients (13.1%) received an inappropriate shock.</AbstractText>The findings support the efficacy and safety of the S-ICD System for the treatment of life-threatening ventricular arrhythmias.</AbstractText> |
12,733 | Association between renal function, diastolic dysfunction, and postoperative atrial fibrillation following cardiac surgery. | Renal dysfunction is associated with a higher rate of atrial fibrillation in clinical practice. This study investigated the associations between renal function, left ventricular (LV) diastolic dysfunction, and postoperative atrial fibrillation (POAF).</AbstractText>A total of 265 consecutive patients who underwent cardiac surgery were prospectively enrolled in the study. Echocardiography was performed before cardiac surgery. The patients were divided into 3 groups based on estimated glomerular filtration rate (eGFR) (group 1, ≥90ml·min(-1)·1.73m(-2); group 2, 60-90ml·min(-1)·1.73m(-2); and group 3, <60ml·min(-1)·1.73m(-2)). POAF occurred in 83 of 265 patients (31.3%). The rate of new-onset POAF increased from 15.2% (12/79) in group 1 to 27.8% (27/97) in group 2 and 49.4% (44/89) in group 3 (P<0.001). Further, with increasing renal dysfunction from groups 1 to 3, the rate of LV diastolic dysfunction - defined as E/e' >15 - also increased (group 1, 19.0%; group 2, 38.1%; and group 3, 48.3%; P<0.001). Absolute eGFR was significantly correlated with E/e' ratio (r=-0.39, P<0.001). Renal function remained as the independent predictor of POAF on multivariate analysis (odds ratio, 1.90; 95% confidence interval: 1.26-2.87; P=0.002).</AbstractText>In patients undergoing cardiac surgery, decreased eGFR was associated with an increased rate of LV diastolic dysfunction with a subsequent increase in the rate of POAF.</AbstractText> |
12,734 | Imaging techniques in electrophysiology and implantable device procedures: results of the European Heart Rhythm Association survey. | The purpose of this European Heart Rhythm Association (EHRA) survey is to assess the implementation and use of imaging techniques in cardiac electrophysiology (EP) and device procedures across European cardiovascular centres. Forty European centres, all members of the EHRA EP research network, responded to this survey. Thirty-one centres (88%) use transthoracic echocardiography (TTE) to evaluate left atrial size and/or volume before atrial fibrillation (AF) ablation. Sixteen centres (46%) perform delayed-enhancement cardiac magnetic resonance imaging (MRI) to guide ventricular tachycardia ablation. Electroanatomical mapping (EAM) systems are available in >65% of responding centres and the use of robotic catheter and remote magnetic navigation systems is limited to <10%. Fusion of EAM data with cardiac computed tomography (CT) and/or MRI is performed in up to 43% of AF ablation procedures. Seventeen out of 35 (49%) responding centres also perform TTE to predict a favourable response to cardiac resynchronization therapy (CRT). Imaging of the cardiac venous system with CT and identification of myocardial scar using CT or MRI, is not routinely performed in the majority of centres [32 (91%) and 26 (75%) centres, respectively) prior to CRT. This EHRA survey shows that several imaging techniques are used to guide catheter ablation and CRT procedures in European centres. Echocardiographic imaging, EAM techniques, and cardiac CT/MRI are commonly used. |
12,735 | Bisoprolol reversed small conductance calcium-activated potassium channel (SK) remodeling in a volume-overload rat model. | A recent study indicated that apamin-sensitive current (I KAS, mediated by apamin-sensitive small conductance calcium-activated potassium channels subunits) density significantly increased in heart failure and led to recurrent spontaneous ventricular fibrillation. While the underlying molecular correlation with SK channels is still undetermined, we hypothesized that they are remodeled in HF and that bisoprolol could reverse the remodeling. Volume-overload models were created on male Sprague-Dawley rats by producing an abdominal arteriovenous fistula. Confocal microscopy, quantitative real-time PCR, and western blot were performed to investigate the expression of SK channels and observe the influence of β-blocker bisoprolol on the expression of SK channels I KAS, and the effect of bisoprolol on I KAS and the sensitivity of I KAS to [Ca(2+)]i at single isolated cells were also explored using whole-cell patch clamp techniques. SK channels were remodeled in HF rats, displaying the significant increase of SK1 and SK3 channel expression. After the treatment of HF rats with bisoprolol, the expression of SK1 and SK3 channels was significantly downregulated, and bisoprolol effectively downregulated I KAS density as well as the sensitivity of I KAS to [Ca(2+)]i. Our data indicated that the expression of SK1 and SK3 increased in HF. Bisoprolol effectively attenuated the change and downregulated I KAS density as well as the sensitivity of I KAS to [Ca(2+)]i. |
12,736 | Impact of the right ventricular lead position on clinical outcome and on the incidence of ventricular tachyarrhythmias in patients with CRT-D. | Data on the impact of right ventricular (RV) lead location on clinical outcome and ventricular tachyarrhythmias in cardiac resynchronization therapy with defibrillator (CRT-D) patients are limited.</AbstractText>To evaluate the impact of different RV lead locations on clinical outcome in CRT-D patients enrolled in the Multicenter Automatic Defibrillator Implantation Trial-Cardiac Resynchronization Therapy trial.</AbstractText>We investigated 742 of 1089 CRT-D patients (68%) with adjudicated RV lead location enrolled in the Multicenter Automatic Defibrillator Implantation Trial-Cardiac Resynchronization Therapy trial to evaluate the impact of RV lead location on cardiac events. The primary end point was heart failure or death; secondary end points included ventricular tachycardia (VT), ventricular fibrillation (VF), or death and VT or VF alone.</AbstractText>Eighty-six patients had the RV lead positioned at the RV septal or right ventricular outflow tract region, combined as nonapical RV group, and 656 patients had apical RV lead location. There was no difference in the primary end point in patients with nonapical RV lead location versus those with apical RV lead location (hazard ratio [HR] 0.98; 95% confidence interval [CI] 0.54-1.80; P = .983). Echocardiographic response to CRT-D was comparable across RV lead location groups (P > .05 for left ventricular end-diastolic volume, left ventricular end-systolic volume, and left atrial volume percent change). However, nonapical RV lead location was associated with significantly higher risk of VT/VF/death (HR 2.45; 95% CI 1.36-4.41; P = .003) and VT/VF alone (HR 2.52; 95% CI 1.36-4.65; P = .002), predominantly in the first year after device implantation. Results were consistent in patients with left bundle branch block.</AbstractText>In CRT-D patients, there is no benefit of nonapical RV lead location in clinical outcome or echocardiographic response. Moreover, nonapical RV lead location is associated with an increased risk of ventricular tachyarrhythmias, particularly in the first year after device implantation.</AbstractText>Published by Elsevier Inc.</CopyrightInformation> |
12,737 | New image processing and noise reduction technology allows reduction of radiation exposure in complex electrophysiologic interventions while maintaining optimal image quality: a randomized clinical trial. | Despite their carcinogenic potential, X-rays remain indispensable for electrophysiologic (EP) procedures.</AbstractText>The purpose of this study was to evaluate the dose reduction and image quality of a novel X-ray technology using advanced image processing and dose reduction technology in an EP laboratory.</AbstractText>In this single-center, randomized, unblinded, parallel controlled trial, consecutive patients undergoing catheter ablation for complex arrhythmias were eligible. The Philips Allura FD20 system allows switching between the reference (Allura Xper) and the novel X-ray imaging technology (Allura Clarity). Primary end-point was overall procedural patient dose, expressed in dose area product (DAP) and air kerma (AK). Operator dose, procedural success, and necessity to switch to higher dose settings were secondary end-points.</AbstractText>A total of 136 patients were randomly assigned to the novel imaging group (n = 68) or the reference group (n = 68). Baseline characteristics were similar, except patients in the novel imaging group were younger (58 vs 65 years, P < .01). Median DAP and AK were 43% and 40% lower in the novel imaging group, respectively (P < .0001). A 50% operator dose reduction was achieved in the novel imaging group (P < .001). Fluoroscopy time, number of exposure frames, and procedure duration were equivalent between the two groups, indicating that the image quality was similarly adequate in both groups. Procedural success was achieved in 91% of patients in both groups; one pericardial tamponade occurred in the novel imaging group.</AbstractText>The novel imaging technology, Allura Clarity, significantly reduces patient and operator dose in complex EP procedures while maintaining image quality.</AbstractText>© 2013 Heart Rhythm Society. All rights reserved.</CopyrightInformation> |
12,738 | Arrhythmias in patients with acute coronary syndrome in the first 24 hours of hospitalization. | In patients with acute coronary syndrome (ACS), we sought to: 1) describe arrhythmias during hospitalization, 2) explore the association between arrhythmias and patient outcomes, and 3) explore predictors of the occurrence of arrhythmias.</AbstractText>In a prospective sub-study of the IMMEDIATE AIM study, we analyzed electrocardiographic (ECG) data from 278 patients with ACS. On emergency department admission, a Holter recorder was attached for continuous 12-lead ECG monitoring.</AbstractText>Approximately 22% of patients had more than 50 premature ventricular contractions (PVCs) per hour. Non-sustained ventricular tachycardia (VT) occurred in 15% of patients. Very few patients (≤ 1%) had a malignant arrhythmia (sustained VT, asystole, torsade de pointes, or ventricular fibrillation). Only more than 50 PVCs/hour independently predicted an increased length of stay (p < .0001). No arrhythmias predicted mortality. Age greater than 65 years and a final diagnosis of acute myocardial infarction independently predicted more than 50 PVCs per hour (p = .0004).</AbstractText>Patients with ACS seem to have fewer serious arrhythmias today, which may have implications for the appropriate use of continuous ECG monitoring.</AbstractText>Copyright © 2013 Elsevier Inc. All rights reserved.</CopyrightInformation> |
12,739 | Signal integral for optimizing the timing of defibrillation. | The possibility of successful defibrillation decreases with an increased duration of ventricular fibrillation (VF). Futile electrical shocks are inversely correlated with myocardial contractile function and long-term survival. Previous studies have demonstrated that various ECG waveform analyses predict the success of defibrillation. This study investigated whether the absolute amplitude of pre-shock VF waveform is likely to predict the success of defibrillation.</AbstractText>ECG recordings of 350 out-of-hospital cardiac arrest (OOHCA) patients were obtained from the automated external defibrillator (AED) and analyzed by the method of signal integral. Successful defibrillation was defined as organized rhythm with heart rate ≥40beat/min commencing within one min of post-shock period and persisting for a minimum of 30s.</AbstractText>Signal integral was significantly greater in successful defibrillation than unsuccessful defibrillation (81.76±32.3mV vs. 34.9±15.33mV, p<0.001). The intersection of the sensitivity and specificity curve provided a threshold value of 51mV. The corresponding values of sensitivity, specificity, positive predictive and negative predictive values for successful defibrillation were 90%, 86%, 80% and 93%, respectively. The receiver operator curve further revealed that signal integral predicted the likelihood of successful defibrillation (area under the curve=0.949).</AbstractText>Signal integral predicted successful electrical shocks on patients with ventricular fibrillation and have potential to optimize the timing of defibrillation and reduce the number of electrical shocks.</AbstractText>Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
12,740 | Comparative analysis of clinical, electrocardiographic, angiographic and echocardiographic data of indigenous and non-indigenous residents of Yakutia with coronary artery atherosclerosis. | The aim of the study is to compare clinical, angiographic, electrocardiographic, echocardiographic data between indigenous and non-indigenous residents of Yakutia.</AbstractText>We performed cross-sectional analysis of the Registry of Selective Coronary Angiography (SCAG) of the Yakutsk Republican Hospital for the period from 2004 to 2007. All patients (n = 1,233) were admitted to hospital from all 35 regions of the Sakha Republic (Yakutia). Initially, 12 (1%) patients, who had abnormal coronary arteries and 259 (21%) patients with normal coronary arteries were excluded from this study. From the remaining 962 (78%) patients with detected coronary artery atherosclerosis 394 (41%) patients were excluded for having congenital heart malformations due to possible influence on the outcomes of examination for myocardial hypertrophy. Finally, only 568 patients were selected for further examinations.</AbstractText>We analyzed clinical data, and the findings of selective angiography, multi-detector computed tomography (CT), electrocardiography (ECG), 24-hour Holter ECG monitoring and echocardiography.</AbstractText>(a) In the Sakha Republic (Yakutia) single-vessel coronary disease, coronary stenosis with 50-75% and 75-90% of constriction were detected more often among indigenous males, while multiple-vessel coronary stenosis was detected more often among non-indigenous males as well as stenosis with more than 90% of constriction. Lower calcium score mean (349.1 ± 129.8 vs. 621.8 ± 115.2) was observed among indigenous patients compared to non-indigenous patients; (b) Painless myocardial infarction, painless ischaemia, arterial hypertension and atrial fibrillation were detected more often among indigenous male compared to non-indigenous participants; (c) Based on the results of ECG and echocardiographic examinations, left ventricular (LV) hypertrophy, particular eccentric type of hypertrophy, was found more commonly among indigenous than non-indigenous males; and (d) By laboratory findings, indigenous males had significantly lower triglyceride levels, while platelet counts were higher compared to non-indigenous patients. Obesity was observed less frequently among indigenous men compared to non-indigenous men.</AbstractText>The differences observed in this study are disputable and call for further studies. Collection of reliable data for women should be the aim of future studies.</AbstractText> |
12,741 | Relationship between seizure episode and sudden cardiac arrest in patients with epilepsy: a community-based study. | Among patients with epilepsy, sudden cardiac arrest (SCA) is a major cause of death. It is commonly thought that SCA in epilepsy occurs after a seizure, though the strength of evidence supporting this is limited. We sought to evaluate the relationship between seizures and SCA in patients with epilepsy.</AbstractText>From the ongoing Oregon Sudden Unexpected Death Study, cases of SCA identified using prospective, multisource ascertainment (Portland metropolitan area, Oregon; population≈1 million; February 1, 2002, to March 1, 2012) were evaluated for history of epilepsy. In the subset with witnessed SCA, clinical presentations were analyzed for evidence of seizure activity immediately before the event as well as lifetime clinical history, including nature of seizures before SCA. Only 34% of patients with history of epilepsy and a witnessed arrest had evidence of seizure activity before the arrest. Rates of survival to hospital discharge after attempted resuscitation were 2.7% in patients with history of epilepsy versus 11.9% for patients without epilepsy (P=0.014). Patients with epilepsy had a significantly lower rate of presentation with ventricular tachycardia/ventricular fibrillation as opposed to pulseless electrical activity/asystole (epilepsy, 26%; no epilepsy, 44%; P=0.002), despite nearly identical response times.</AbstractText>In the majority (66%) of epilepsy patients, there was no relationship between seizure and SCA, implying that SCA in epilepsy patients often may not involve seizure as a trigger. The significantly worse rate of survival from SCA in epilepsy patients warrants urgent investigation.</AbstractText> |
12,742 | Inadvertently Developed Ventricular Fibrillation during Electrophysiologic Study and Catheter Ablation: Incidence, Cause, and Prognosis. | Ventricular fibrillation (VF) can inadvertently occur during electrophysiologic study (EPS) or catheter ablation. We investigated the incidence, cause, and progress of inadvertently developed VF during EPS and catheter ablation.</AbstractText>We reviewed patients who had developed inadvertent VF during EPS or catheter ablation. Patients who developed VF during programmed ventricular stimulation to induce ventricular tachycardia or VF were excluded.</AbstractText>Inadvertent VF developed in 11 patients (46.7±9.3 years old) among 2624 patients (0.42%); during catheter ablation for atrial fibrillation (AF) in nine patients, frequent ventricular premature beats (VPBs) in one, and Wolff-Parkinson-White (WPW) syndrome were observed in one. VF was induced after internal cardioversion in six AF patients due to incorrect R-wave synchronization of a direct current shock. Two AF patients showed spontaneous VF induction during isoproterenol infusion while looking for AF triggering foci. The remaining AF patient developed VF after rapid atrial pacing to induce AF, but the catheter was accidentally moved to the right ventricular (RV) apex. A patient with VPB ablation spontaneously developed VF during isoproterenol infusion. The focus of VPB was in the RV outflow tract and successfully ablated. A patient with WPW syndrome developed VF after rapid RV pacing with a cycle length of 240 ms. Single high energy (biphasic 150-200 J) external defibrillation was successful in all patients, except in two, who spontaneously terminated VF. The procedure was uneventfully completed in all patients. At a mean follow-up period of 17.4±15.5 months, no patient presented with ventricular arrhythmia.</AbstractText>Although rare, inadvertent VF can develop during EPS or catheter ablation. Special caution is required to avoid incidental VF during internal cardioversion, especially under isoproterenol infusion.</AbstractText> |
12,743 | Longitudinal changes in intracardiac repolarization lability in patients with implantable cardioverter-defibrillator. | While it is known that elevated baseline intracardiac repolarization lability is associated with the risk of fast ventricular tachycardia (FVT)/ventricular fibrillation (VF), the effect of its longitudinal changes on the risk of FVT/VF is unknown.</AbstractText>Near-field (NF) right ventricular (RV) intracardiac electrograms (EGMs) were recorded every 3-6 months at rest in 248 patients with structural heart disease [mean age 61.2 ± 13.3; 185(75%) male; 162(65.3%) ischemic cardiomyopathy] and implanted cardioverter-defibrillator (ICD) or cardiac resynchronization therapy defibrillator (CRT-D) [201 (81%) primary prevention]. Intracardiac beat-to-beat QT variability index (QTVINF) was measured on NF RV EGM. During the first study phase (median 18 months), participants made on average 2.4 visits. Then remote follow-up was continued for an additional median period of 3 years. Average QTVINF did not change during the first year after ICD implantation (-0.342 ± 0.603 at baseline vs. -0.262 ± 0.552 at 6 months vs. -0.334 ± 0.603 at 12 months); however, it decreased thereafter (-0.510 ± 0.603 at 18 months; P = 0.042). Adjusted population-averaged GEE model showed that the odds of developing FVT/VF increased by 75% for each 1 unit increase in QTVINF. (OR 1.75 [95%CI 1.05-2.92]; P = 0.031). However, individual patient-specific QTVINF trends (increasing, decreasing, flat) varied from patient to patient. For a given patient, the odds of developing FVT/VF were not associated with increasing or decreasing QTVINF over time [OR 1.27; (95%CI 0.05-30.10); P = 0.881].</AbstractText>While on average the odds of FVT/VF increased with an increase in QTVINF, patient-specific longitudinal trends in QTVINF did not affect the odds of FVT/VF.</AbstractText> |
12,744 | The SCN5A mutation A1180V is associated with electrocardiographic features of LQT3. | Mutations of the SCN5A gene are associated with several arrhythmic syndromes including the Brugada syndrome, conduction disease, long QT syndrome type 3 (LQT3), atrial fibrillation, and dilated cardiomyopathy. We report LQT3 associated with an A1180V cardiac sodium channel mutation, previously associated with cardiac conduction block, and dilated cardiomyopathy in three generations of a Chinese family. Clinical, electrocardiographic (ECG), and echocardiographic examination was followed by direct sequencing of SCN5A and HERG to screen genomic DNA from blood samples. The proband presented with multiple syncopes from the age of 7 years and was found to share a mutation with two other members of his family. Continuous ECG monitoring after presentation showed prolonged QTc and biphasic T waves, multiple episodes of ventricular tachycardia and torsades de pointes. The other two mutation carriers showed ECG features of LQT3 without clinical symptoms. Transthoracic echocardiography showed normal cardiac structure in all three mutation carriers. This study shows LQT3 features associated with an A1180V cardiac sodium channel mutation, expanding the spectrum of phenotypes resulting from this mutation in which biophysical study has shown a persistent late Na(+) current. |
12,745 | Ventricular activity cancellation in electrograms during atrial fibrillation with constraints on residuals' power. | During atrial fibrillation (AF), cancellation of ventricular activity from atrial electrograms (AEG) is commonly performed by template matching and subtraction (TMS): a running template, built in correspondence of QRSs, is subtracted from the AEG to uncover atrial activity (AA). However, TMS can produce poor cancellation, leaving high-power residues. In this study, we propose to modulate the templates before subtraction, in order to make the residuals as similar as possible to the nearby atrial activity, avoiding high-power ones. The coefficients used to modulate the template are estimated by maximizing, via Multi-swarm Particle Swarm Optimization, a fitness function. The modulated TMS method (mTMS) was tested on synthetic and real AEGs. Cancellation performances were assessed using: normalized mean squared error (NMSE, computed on simulated data only), reduction of ventricular activity (VDR), and percentage of segments (PP) whose power was outside the standard range of the atrial power. All testings suggested that mTMS is an improvement over TMS alone, being, on simulated data, NMSE and PP significantly decreased while VDR significantly increased. Similar results were obtained on real electrograms (median values of CS1 recordings PP: 2.44 vs. 0.38 p < 0.001; VDR: 6.71 vs. 8.15 p < 0.001). |
12,746 | Characteristics of patients that experience cardiopulmonary arrest following aortic dissection and aneurysm. | The aim of this study is to investigate the characteristics of patients experience cardiopulmonary arrest (CPA) in the acute phase following aortic dissection and aneurysm (AD).</AbstractText>Patients who were transported to this department from January 2005 to December 2010 and subsequently diagnosed with AD were included in this study. Patients with asymptomatic AD or those with AD that did not develop CPA were excluded. The AD was classified into four categories: Stanford A (SA), Stanford B (SB), thoracic aortic aneurysm (TAA) and abdominal aortic aneurysm (AAA). The frequency of witnessed collapse, gender, average age, past history including hypertension, vascular complications and diabetes mellitus, the initial complaint at the timed of dissection, initial electrocardiogram at scene, classification of CPA and survival ratio were compared among the patient groups.</AbstractText>There were 24 cases of SA, 1 case of the SB, 8 cases of ruptured TAA and 9 cases of ruptured AAA. The frequency of males among all subjects was 69%, the average age was 72.3 years old and the frequency of hypertension was 47.6%. There was no ventricular fibrillation (VF) when the patients with AD collapsed. A loss of consciousness was the most common complaint. The outcome of the subjects was poor; however, three patients with SA achieved social rehabilitation. Two out of the three had cardiac tamponade and underwent open heart massage.</AbstractText>The current study revealed that mortality of cardiac arrest caused by the AD remains very high, even when return of spontaneous circulation was obtained. VF was rare when the patients with AD collapsed. While some cases with CPA of SA may achieve a favorable outcome following immediate appropriate treatment.</AbstractText> |
12,747 | Functional mitral regurgitation after a first non-ST segment elevation acute coronary syndrome: very-long-term follow-up, prognosis and contribution to left ventricular enlargement and atrial fibrillation development. | To assess the relationship between functional mitral regurgitation (MR) after a non-ST segment elevation acute coronary syndrome (NSTSEACS) and long-term prognosis, ventricular remodelling and further development of atrial fibrillation (AF), since functional MR is common after myocardial infarction.</AbstractText>Prospective cohort study conducted in a tertiary referral centre.</AbstractText>We prospectively studied 237 patients consecutively discharged in New York Heart Association class I-II (74% men; mean age 66.1 years) after a first NSTSEACS. All underwent an ECG the first week after admission and were echocardiographically and clinically followed-up (median 6.95 years).</AbstractText>MR was detected in 95 cases (40.1%) and became an independent risk factor for the development of heart failure (HF) and major adverse cardiovascular events (MACE) (per MR degree, HRHF 1.71, 95% CI 1.138 to 2.588, p=0.01; HRMACE 1.49, 95% CI 1.158 to 1.921, p=0.002). Left ventricular diastolic (grade I 12.7±40.7; grade II 26.8±12.4; grade III 46.3±50.9 mL, p=0.01) and systolic (grade I 10.4±37.3; grade II 10.12±12.7; grade III 36.8±46.0 mL, p=0.02) mean volumes were higher after follow-up in patients with MR, in proportion to the initial degree of MR. In the rhythm analysis (126 patients; previously excluding those with any history of AF) during follow-up, 11.4% of patients with degree I MR, 14.3% with degree II MR and 75% with degree III MR developed AF, while only 5.1% of those with degree 0 developed AF, p<0.001.</AbstractText>MR is common after an NSTSEACS. The presence and greater degree of MR confers a worse long-term prognosis after a first NSTSEACS. This can in part be explained by increased negative ventricular remodelling and increased occurrence of AF.</AbstractText> |
12,748 | Ringless alfieri mitral valve repair for significant ischemic mitral regurgitation with coronary artery bypass grafting. | Ischemic mitral regurgitation (IMR) is associated with diminished survival prospects. Ringless edge-to-edge mitral valve repair is usually performed in association with coronary artery bypass grafting (CABG). In this report, we present our early results for ringless edge-to-edge repair and concomitant CABG.</AbstractText>Between January 2011 and June 2012, 17 patients underwent ringless edge-to-edge mitral valve repair. The cause was ischemic in all patients. A double-orifice repair was done in all patients. Complete coronary revascularization was routinely added in all cases.</AbstractText>There were no hospital and late deaths. Low cardiac output developed in 5 patients (29.41%) and was treated with inotropic agents. Two of these patients required intraaortic balloon pump support. Atrial fibrillation and ventricular arrhythmia developed in 5 (29.41%) of the patients, and all of them converted to sinus rhythm with antiarrhythmic agents. The mean (SD) stays in the intensive care unit and the hospital were 2.83 ± 1.29 days and 7.74 ± 2.14 days, respectively. As of the latest follow-up, all patients were in New York Heart Association class I or II. There was no recurrent mitral valve regurgitation or valve-related complications.</AbstractText>Alfieri mitral valve repair is associated with lower risks of mortality, postoperative stroke, and prolonged intensive care unit and hospital stays. Alfieri mitral valve repair and concomitant CABG surgery can be performed in patients with IMR.</AbstractText> |
12,749 | A comparison of clinical characteristics and long-term prognosis in asymptomatic and symptomatic patients with first-diagnosed atrial fibrillation: the Belgrade Atrial Fibrillation Study. | To investigate baseline characteristics and long-term prognosis of carefully characterized asymptomatic and symptomatic patients with atrial fibrillation (AF) in a 'real-world' cohort of first-diagnosed non-valvular AF over a 10-year follow-up period.</AbstractText>We conducted an observational, non-interventional, and single-centre registry-based study of consecutive first-diagnosed AF patients. Of 1100 patients (mean age 52.7±12.2 years and mean follow-up 9.9±6.1 years), 146 (13.3%) had asymptomatic AF. Persistent or permanent AF, slower ventricular rate during AF (<100/min), CHA2DS2-VASc score of 0, history of diabetes mellitus and male gender were independent baseline risk factors for asymptomatic AF presentation (all p<0.01) with a good predictive ability of the multivariable model (c-statistic 0.86, p<0.001). Kaplan-Meier 10-year estimates of survival free of progression of AF (log-rank test=33.4, p<0.001) and ischemic stroke (log-rank test=6.2, p=0.013) were significantly worse for patients with asymptomatic AF compared to those with symptomatic arrhythmia. In the multivariable Cox regression analysis, intermittent asymptomatic AF was significantly associated with progression to permanent AF (Hazard Ratio 1.6; 95% CI, 1.1-2.2; p=0.009).</AbstractText>In a 'real-world' setting, patients with asymptomatic presentation of their first-diagnosed AF could have different risk profile and long-term outcomes compared to those with symptomatic AF. Whether more intensive monitoring and comprehensive AF management including AF ablation at early stage following the incident episode of AF and increased quality of oral anticoagulation could alter the long-term prognosis of these patients requires further investigation.</AbstractText>© 2013.</CopyrightInformation> |
12,750 | Acute myocardial infarction and massive pulmonary embolus presenting as cardiac arrest: initial rhythm as a diagnostic clue. | Myocardial infarction (MI) and massive pulmonary embolism (MPE) are common causes of cardiac arrest. We present two cases with similar clinical presentation and EKG findings but different initial rhythms. Case  1. A 55-year-old African American male (AAM) was brought to the emergency room (ER) with cardiac arrest and pulseless electrical activity (PEA). Twelve-lead electrocardiogram (EKG) was suggestive of ST segment elevations (STEs) in anterolateral leads. Coronary angiogram did not reveal any significant obstruction. An echocardiogram was suggestive of a pulmonary embolus (PE). Autopsy revealed a saddle PE. Case  2. A 45-year-old AAM with a history of coronary artery disease was brought to the ER after ventricular fibrillation (VF) arrest. Twelve-lead EKG was suggestive of STE in anterior leads. Coronary angiogram revealed in-stent thrombosis. In cardiac arrests, distinguishing the two major etiologies (MI and MPE) can be challenging. PEA is more commonly associated with MPE versus MI due to near complete obstruction of pulmonary blood flow with an intact electrical conduction system. MI is more commonly associated with VF as the electrical conduction system is affected more often by ischemia. In conclusion, the previous cases illustrate that initial rhythm may be a vital diagnostic clue. |
12,751 | Fragmented QRS predicts cardiovascular death of patients with structural heart disease and inducible ventricular tachyarrhythmia. | Fragmented QRS (fQRS) can predict cardiac events, and inducible ventricular tachycardia/fibrillation (VT/VF) is a known high-risk factor for arrhythmic death. However, whether fQRS is a predictor of cardiac events in patients with inducible VT/VF is unknown. We aimed to evaluate whether fQRS is a predictor of cardiac events in patients with structural heart disease and inducible VT/VF.</AbstractText>We retrospectively investigated 98 patients with structural heart disease who had a defibrillator device implanted. All patients underwent electrophysiological testing prior to or after device implantation and VT/VF was induced. fQRS was present in 30 patients. Appropriate defibrillator therapies were similar between the fQRS and non-fQRS groups (47% vs. 47%). In total, 25 patients (26%) died during a mean follow-up period of 87±43 months. All-cause mortality (12 [40%] vs. 13 [19%]) and cardiovascular deaths (9 [30%] vs. 4 [6%]) were significantly higher in the fQRS group than non-fQRS group, respectively; Kaplan-Meier analysis revealed significantly lower event-free survival for all-cause mortality (P=0.012) and cardiovascular deaths (P=0.001) for fQRS patients. A multivariable Cox regression model revealed that fQRS was an independent predictor of cardiovascular death (hazard ratio, 4.58; 95% confidence interval, 1.34-15.64; P=0.015).</AbstractText>fQRS is a predictor of cardiovascular death in patients with structural heart disease and inducible VT/VF.</AbstractText> |
12,752 | The prognostic impact of pre-implantation hyponatremia on morbidity and mortality among patients with left ventricular dysfunction and implantable cardioverter-defibrillators. | Hyponatremia is commonly observed among patients with left ventricular (LV) dysfunction and is a marker for adverse outcomes. We aimed to determine the prognostic significance of pre-implant hyponatremia on the outcomes of death, acute decompensated heart failure (ADHF) and appropriate implantable cardioverter-defibrillator (ICD) therapy for ventricular arrhythmias among patients with ICDs.</AbstractText>The study population consisted of patients with an ejection fraction ≤40% undergoing ICD implantation (n = 911) for the primary or secondary prevention of sudden cardiac death from 1997 to 2007. The predictive value of the severity of pre-implantation hyponatremia stratified into mild hyponatremia (n = 268, sodium 134-136 mmol/L), moderate hyponatremia (n = 105, sodium 131-133 mmol/L), and severe hyponatremia (n = 31, sodium ≤130 mmol/L) on the risk of death, ADHF, and appropriate ICD therapy for ventricular arrhythmias as compared with patients a normal serum sodium (n = 507, sodium ≥ 137 mmol/L), was calculated using multivariable Cox proportional hazards analyses. During a mean follow-up of 775 ± 750 days as the severity of hyponatremia (from a normal sodium to severe hyponatremia) increased an incremental incidence of death (25% to 61%, P < 0.001) and ADHF (11% to 26%, P = 0.004) was observed with a reduced incidence of ICD therapy for ventricular tachycardia/ventricular fibrillation (37-29%, P = 0.037). Compared with the normal sodium cohort, patients with severe hyponatremia demonstrated an increased risk of death [adjusted hazard ratio (AHR) 2.69 (95% confidence interval, CI 1.57-4.59), P = 0.004] and ADHF [AHR 2.98 (95% CI 1.41-6.30), P = 0.004], with a lower probability of appropriate ICD therapy [AHR 0.68 (95% CI 0.27-0.88), P = 0.031].</AbstractText>Hyponatremia is commonly observed among ICD recipients with LV dysfunction. Patients with an increasing severity of hyponatremia are at increased risk of death and HF related morbidity with a reduced incidence of appropriate ICD therapy particularly among patients with severe hyponatremia.</AbstractText> |
12,753 | Clinical examination for prognostication in comatose cardiac arrest patients. | To build new algorithms for prognostication of comatose cardiac arrest patients using clinical examination, and investigate whether therapeutic hypothermia influences the value of the clinical examination.</AbstractText>From 2000 to 2007, 500 consecutive patients in non-traumatic coma were prospectively enrolled, 200 of whom were post-cardiac arrest. Outcome was determined by modified Rankin Scale (mRS) score at 6 months, with mRS≤3 indicating good outcome. The clinical examination was performed on days 0, 1, 3 and 7 post-arrest, and clinical variables analyzed for importance in prognostication of outcome. A classification and regression tree analysis (CART) was used to develop a predictive algorithm.</AbstractText>Good outcome was achieved in 9.9% of patients. In CART analysis, motor response was often chosen as a root node, and spontaneous eye movements, pupillary reflexes, eye opening and corneal reflexes were often chosen as splitting nodes. Over 8% of patients with absent or extensor motor response on day 3 achieved a good outcome, as did 2 patients with myoclonic status epilepticus. The odds of achieving a good outcome were lower in patients who suffered asystole (OR 0.187, 95% CI: 0.039-0.875, p=0.033) compared with ventricular fibrillation or non-perfusing ventricular tachycardia, but some still achieved good outcome. The absence of pupillary and corneal reflexes on day 3 remained highly reliable for predicting poor outcome, regardless of therapeutic hypothermia utilization.</AbstractText>The clinical examination remains central to prognostication in comatose cardiac arrest patients in the modern area. Future studies should incorporate the clinical examination along with modern technology for accurate prognostication.</AbstractText>Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
12,754 | [Cardiac resynchronization therapy in patients with permanent atrial fibrillation]. | In our study we compared effect of cardiac resynchronization therapy (CRT) in chronic heart failure (CHF) patients with permanent atrial fibrillation (AF) and patients with sinus rhythm. Special feature of our work was that patients with permanent atrial fibrillation didnt have obligatory ablation of atrio-ventricular node but underwent aggressive rate control to achieve more than 90% of biventricular (BV) complexes. We used 24 hours Holter monitoring because there are data that this method is more accurate than CRT counters.</AbstractText>We included 30 patients: 21 patients with sinus rhythm and 9 patients with permanent AF with ejection fraction <35%, II-IV NYHA class and wide QRS (>120 ms). We examined patients before implantation of CRT and after 6 months.</AbstractText>mean NYHA class decreased from III to II. Distance at 6-min walk test increased by 107 m in AF group and by 105 in sinus rhythm group. EF increased by 7% in AF group and by 6% in sinus rhythm group. Mean time of further observation was 2 years (from 10 months to 5 years). There was 1 death (11.1%) in AF group and 3 deaths (15%) in sinus rhythm group (p>0,05).</AbstractText>CRT is effective in CHF patients with permanent AF and pharmacological rate control if percent of BV pacing is more than 90% on Holter monitoring.</AbstractText> |
12,755 | [Protective action of ethylglutathione at hypoxia-reoxygenation of the heart: role of glucose]. | Glutathione is the main redox buffer in cardiomyocytes. The action of ethylglutathione possessing antioxidant properties on functional disorders evoked by 30-minute hypoxia of the isolated rat heart with subsequent reoxygenation has been studied. In control experiments, the presence of glucose (11 mM) in hypoxic perfusate was associated with lesser hypoxic contracture of the myocardium but also with the development of arrhythmias in all experiments, including ventricular tachycardias and fibrillation that may be due to arisen myocardial heterogeneity. After reoxygenation, a half of hearts in this group demonstrated inability to reproduce high rate of stimulation. These alterations were almost completely prevented when ethylglutathione (0.2 mM) was added into hypoxic perfusate. Its presence in the solution also facilitated 1.5-fold improvement of cardiac function recovery after reoxygenation. The results suggest that the protective action of ethylglutathione may be due to a reduced oxidative modification of ionic transport proteins. At non-glucose hypoxic perfusion, myocardial contracture was higher but abovementioned functional disorders did not arise, and ethylglutathione addition was inefficient. |
12,756 | Effects of high-dose radiotherapy on implantable cardioverter defibrillators: an in vivo porcine study. | Although the effects of radiotherapy (RT) on implantable cardioverter defibrillators (ICDs) have been studied in vitro, and some information has been gathered from case reports and series, no in vivo experiments have previously been performed.</AbstractText>In vivo effects of photon RT applied directly to five modern ICD generators from different manufacturers implanted in pigs were studied. The devices were interrogated between and after increasing doses of ionizing radiation. Afterwards, the shock function was tested.</AbstractText>All ICDs withstood fractionated irradiations with a cumulative dose of 18.5 gray (Gy) of 6 megavolt (MV) photons and 18.5 Gy of 18 MV photons and were still fully functional. Especially, no oversense was recorded. Induced ventricular fibrillation was detected and treated properly by shock therapy in all cases. However, one of the ICDs converted to back-up mode later the same night.</AbstractText>The animal model is feasible for investigating RT effects on implanted cardiac devices. During irradiations with 37 Gy, one recoverable malfunction was present in the tested devices. Additional animal studies could provide supplementary evidence for treating ICD patients, including recommendations for reprogramming of the ICD during RT and avoidance of relocating the device.</AbstractText>©2013, The Authors. Journal compilation ©2013 Wiley Periodicals, Inc.</CopyrightInformation> |
12,757 | Electrophysiology of T-wave alternans: mechanisms and pharmacologic influences. | Extensive experimental evidence indicates a fundamental link between T-wave alternans (TWA) and arrhythmogenesis. Diverse physiologic and pathophysiologic influences alter TWA magnitude in parallel with their effects on vulnerability to ventricular tachyarrhythmias. Specifically, interventions that impede intracellular calcium handling, such as elevated heart rate, heightened adrenergic activity, myocardial ischemia, and heart failure, predispose to greater levels of TWA, reflecting heightened risk for arrhythmias. Conversely, vagus nerve stimulation, blockade of beta-adrenergic receptors and late sodium and L-type calcium channels, and sympathetic denervation decrease TWA magnitude, reflecting the potential of these interventions to reduce risk for ventricular tachycardia and fibrillation. TWA thus appears able to detect the influence of pathophysiologically relevant triggers as well as the efficacy of antiarrhythmic drugs without reducing the predictive capacity of the phenomenon. |
12,758 | Transmural IK(ATP) heterogeneity as a determinant of activation rate gradient during early ventricular fibrillation: mechanistic insights from rabbit ventricular models. | Activation rate (AR) gradients develop during ventricular fibrillation (VF), with the highest AR on the surface near Purkinje system (PS) terminals (endocardium in humans and rabbits and epicardium in pigs). The application of glibenclamide to block adenosine triphosphate (ATP)-sensitive potassium current (IK(ATP)) before VF induction eliminates transmural AR gradients and prevents the induction of sustained arrhythmia. It remains unclear whether the PS, which is resistant to ischemia, is also a factor in AR heterogeneity.</AbstractText>To dissect IK(ATP) and PS contributions to AR gradients during VF by using detailed computer simulations.</AbstractText>We constructed rabbit ventricular models with either subendocardial or subepicardial PS terminals. Physiologically relevant IK(ATP) gradients were implemented, and early VF was induced and observed.</AbstractText>Prominent AR gradients were observed only in models with large IK(ATP) gradients. The critical underlying factor of AR gradient maintenance was refractoriness in low-IK(ATP) regions, which blocked the propagation of action potentials from high-IK(ATP) regions. The PS played no role in transmural AR gradient maintenance, but did cause local spatial heterogeneity of AR on the surface adjacent to terminals. Simulated glibenclamide application during VF led to spontaneous arrhythmia termination within a few seconds in most cases, which builds on previous experimental findings of anti-VF properties of glibenclamide pretreatment.</AbstractText>Differential IK(ATP) across the ventricular wall is an important factor underlying AR gradients during VF; thus, higher epicardial AR in pigs is most likely due to an abundance of epicardial IK(ATP). For terminating early VF, our results suggest that IK(ATP) modulation is a stronger target than Purkinje ablation.</AbstractText>© 2013 Heart Rhythm Society. All rights reserved.</CopyrightInformation> |
12,759 | Impact of atrial fibrillation on early complications and one year-survival after cardioverter defibrillator implantation: results from the German DEVICE registry. | Outcome data of patients with implantable cardioverter defibrillators (ICD) and atrial fibrillation (AF) are conflicting. The German DEVICE registry aims to add further information on this particular cohort.</AbstractText>The German DEVICE registry is a nationwide prospective multicenter database of ICD implantations. 3261 patients are included (81% males, 2701 (82.8%) first ICD implantations, 560 (17.2%) ICD replacements). Cardiac resynchronization therapy (CRT-D) was performed in 882 patients (27.0%). Sinus rhythm (SR) was present in 2654 (81.4%) and atrial fibrillation (AF) in 607 (18.6%). Left ventricular ejection fraction (LVEF) did not differ between groups (SR 32.3%, AF 30.4%; p = 0.09). AF patients were older (AF 70.9 versus SR 63.9 years; p < 0.0001), presented with more co-morbidities (diabetes, hypertension, chronic kidney disease; all p < 0.001). In-hospital complications were not significantly different between groups (p = 0.58). Follow-up information after one year was available in 2967 patients (91%). One-year overall mortality after first ICD implantation was 4.9% for SR and 11.2% for AF patients (p < 0.0001); mortality one year after ICD replacement was 8.4% for SR and 12.0% for AF (p = 0.34). No statistically significant difference between SR and AF patients receiving a CRT device was observed (SR 6.9%, AF 10.7%, p = 0.16) in terms of one-year mortality.</AbstractText>The German DEVICE registry demonstrates that patients with AF who receive ICD devices are older, have more co-morbidity and more severe heart failure. AF carries an independent 1.39 fold risk (95% CI 1.02-1.89) of death after one year in patients only with first ICD implantation.</AbstractText>© 2013.</CopyrightInformation> |
12,760 | Clinical efficacy of dofetilide for the treatment of atrial tachyarrhythmias in adults with congenital heart disease. | Atrial tachyarrhythmias (AT) including atrial fibrillation (AF), atrial flutter (AFL), and atrial tachycardia represent a clinical challenge in the adult with congenital heart disease (CHD). Dofetilide (D) is a rapidly activating delayed rectifier potassium channel (IKr) blocker effective in pharmacological conversion and maintenance of normal sinus rhythm in patients with AF and AFL. There is limited knowledge regarding the role of D in adults with CHD.</AbstractText>Safety and efficacy of D was evaluated in a consecutive group of thirteen adult patients (age 40 ± 11; six women) with CHD and refractory AT.</AbstractText>Ten patients had persistent (four AFL, one AF, and five atrial tachycardia) and three paroxysmal (one AF and two atrial tachycardia) AT. All patients were symptomatic during tachycardia, 12 patients had previously failed 2 ± 1 antiarrhythmic drugs. Mean systemic ventricular ejection fraction was 55 ± 9%; baseline QRS complex duration was 129 ± 45 ms (>120 ms in six patients). Patients were followed on D for 33 ± 39 months (median 16). Among 10 patients with persistent AT, seven patients (70%) pharmacologically converted to sinus rhythm on D and three patients (30%) required direct current cardioversion. Two patients (15.4%) experienced complete arrhythmia suppression, and seven (53.8%) experienced significant clinical improvement with sporadic recurrences; average time to recurrence was 5.5 ± 3.5 months. One patient developed torsade de pointes during loading, and the drug was discontinued. D was discontinued in five (38.5%) other patients due to recurrence of AT (n = 4) and renal failure (n = 1). Corrected QT interval (QTc) increased from 452 ± 61 to 480 ± 49 ms (P = .04) and corrected JT interval (JTc) from 323 ± 39 to 341 ± 33 ms (P = .09).</AbstractText>D should be considered a pharmacologic alternative when adult patients with CHD develop AT. D does not depress conduction, sinus node, or ventricular function but needs close monitoring for potential ventricular pro-arrhythmia.</AbstractText>© 2013 Wiley Periodicals, Inc.</CopyrightInformation> |
12,761 | Prophylactic and therapeutic effects of garlic extract on Nerium oleander-induced arrhythmia: a new approach to antiarrhythmic therapy in an ovine model. | Oleander is a potent cardiotoxic plant and is a common cause of poisoning in human and animals. There is no affordable and cost-effective treatment for oleander poisoning. Objective. To evaluate the prophylactic and therapeutic effects of garlic extract (Allium sativum) on Nerium oleander (a potent cardiotoxic plant) intoxication in sheep.</AbstractText>Eight sheep were intravenously infused with an unsterilized hydro-ethanol extract of garlic (50 mg/kg) before or after receiving a lethal dose of dried leaves (as a powder) of oleander (100 mg/kg, orally). The cardiac rhythm was continuously monitored using biopotential wireless transmitters and telemetry system. For evaluation of therapeutic effects, six sheep received the lethal dose of oleander and were administered with garlic extract after development of cardiac arrhythmias. Subsequently, the survived animals from the therapeutic study (four sheep) were administered with oleander without receiving any medication. Some blood constituents, including total antioxidant capacity, malondialdehyde, and troponin I, were compared between treated and untreated animals.</AbstractText>Pretreatment with garlic extract reversed the arrhythmia caused by oleander to its previous normal rhythm in seven sheep, but, one sheep died of ventricular fibrillation. On therapeutic treatment, four sheep survived while two died of ventricular fibrillation. Dosing with oleander without receiving garlic extract resulted in death of all sheep due to ventricular fibrillation. Blood constituents did not show any significant changes between treated and untreated sheep, and before and after intoxication.</AbstractText>Garlic extract reduced the case fatality from 100% to 12.5% and 33.3% as a prophylactic or therapeutic agent, respectively. Additionally, garlic extract delayed the time of onset of arrhythmias and prolonged the interval between intoxication and death of the animals. Garlic extract could be considered to be a potential and affordable antidote in oleander poisoning. However additional studies with a larger sample size and in other species need to be performed to confirm the results in this study.</AbstractText> |
12,762 | A comparison of survival following out-of-hospital cardiac arrest in Sydney, Australia, between 2004-2005 and 2009-2010. | To determine whether survival following out-of- hospital cardiac arrest (OHCA) in Sydney, Australia, improved between 2004-2005 and 2009-2010, and whether there was a change in incidence of OHCA.</AbstractText>Retrospective study using the Ambulance Service of New South Wales and NSW Registry of Births, Deaths and Marriages databases.</AbstractText>All patients who had an OHCA in the Sydney metropolitan area and who used the Ambulance Service of NSW between June 2009 and May 2010 (2009-2010), and between June 2004 and May 2005 (2004-2005).</AbstractText>Survival to 90 days. Other outcome measures included the incidence of OHCA and survival to the day following OHCA, 28 days and 1 year following OHCA. Survival and incidence were also calculated according to initial electrocardiograph rhythm.</AbstractText>Survival to 90 days was 12.3% in 2004-2005 and 10.2% in 2009-2010 (P = 0.015). In 2004-2005, the age standardised incidence of OHCA was 52.6 events per 100 000 person-years (95% CI, 51.6-53.6 events per 100 000 person-years), and in 2009-2010 it was 48.4 events per 100 000 person-years (95% CI, 46.3-50.4 events per 100 000 person-years). In 2004-2005, the incidence of ventricular fibrillation (VF) was 31.3% (95% CI, 28.4%- 33.9%) and in 2009-2010 it was 22.1% (95% CI, 20.0%- 24.3%).</AbstractText>There was no improvement in survival following OHCA in Sydney between 2004-2005 and 2009- 2010. There has been a decrease in overall survival from OHCA and a decrease in the overall age-standardised incidence of OHCA. The decrease in overall survival may be due to a decline in the incidence of VF.</AbstractText> |
12,763 | Hyperoxia in the intensive care unit and outcome after out-of-hospital ventricular fibrillation cardiac arrest. | Laboratory and clinical studies have suggested that hyperoxia early after resuscitation from cardiac arrest may increase neurological injury and worsen outcome. Previous clinical studies have been small or have not included relevant prehospital data. We aimed to determine in a larger cohort of patients whether hyperoxia in the intensive care unit in patients admitted after out-of-hospital cardiac arrest (OHCA) was associated with increased mortality rate after correction for prehospital variables.</AbstractText>Data from the Victorian Ambulance Cardiac Arrest Registry (VACAR) of patients transported to hospital after resuscitation from OHCA and an initial cardiac rhythm of ventricular fibrillation between January 2007 and December 2011 were linked to the Australian and New Zealand Intensive Care Society Adult Patient Database (ANZICS-APD). Patients were allocated into three groups (hypoxia [PaO2<60mmHg], normoxia [PaO2,60-299mmHg] or hyperoxia [PaO2≥300mmHg]) according to their most abnormal PaO2 level in the first 24 hours of ICU stay. The relationship between PaO2 and hospital mortality was investigated using multivariate logistic regression analysis to adjust for confounding prehospital and ICU factors.</AbstractText>There were 957 patients identified on the VACAR database who met inclusion criteria. Of these, 584 (61%) were matched to the ANZICS-APD and had hospital mortality and oxygen data available. The unadjusted hospital mortality was 51% in the hypoxia patients, 41% in the normoxia patients and 47% in the hyperoxia patients (P=0.28). After adjustment for cardiopulmonary resuscitation by a bystander, patient age and cardiac arrest duration, hyperoxia in the ICU was not associated with increased hospital mortality (OR, 1.2; 95% CI, 0.51-2.82; P=0.83).</AbstractText>Hyperoxia within the first 24 hours was not associated with increased hospital mortality in patients admitted to ICU following out-of-hospital ventricular fibrillation cardiac arrest.</AbstractText> |
12,764 | Association between early surgical intervention vs watchful waiting and outcomes for mitral regurgitation due to flail mitral valve leaflets. | The optimal management of severe mitral valve regurgitation in patients without class I triggers (heart failure symptoms or left ventricular dysfunction) remains controversial in part due to the poorly defined long-term consequences of current management strategies. In the absence of clinical trial data, analysis of large multicenter registries is critical.</AbstractText>To ascertain the comparative effectiveness of initial medical management (nonsurgical observation) vs early mitral valve surgery following the diagnosis of mitral regurgitation due to flail leaflets.</AbstractText><AbstractText Label="DESIGN, SETTING, AND PARTICIPANTS" NlmCategory="METHODS">The Mitral Regurgitation International Database (MIDA) registry includes 2097 consecutive patients with flail mitral valve regurgitation (1980-2004) receiving routine cardiac care from 6 tertiary centers (France, Italy, Belgium, and the United States). Mean follow-up was 10.3 years and was 98% complete. Of 1021 patients with mitral regurgitation without the American College of Cardiology (ACC) and the American Heart Association (AHA) guideline class I triggers, 575 patients were initially medically managed and 446 underwent mitral valve surgery within 3 months following detection.</AbstractText>Association between treatment strategy and survival, heart failure, and new-onset atrial fibrillation.</AbstractText>There was no significant difference in early mortality (1.1% for early surgery vs 0.5% for medical management, P=.28) and new-onset heart failure rates (0.9% for early surgery vs 0.9% for medical management, P=.96) between treatment strategies at 3 months. In contrast, long-term survival rates were higher for patients with early surgery (86% vs 69% at 10 years, P < .001), which was confirmed in adjusted models (hazard ratio [HR], 0.55 [95% CI, 0.41-0.72], P < .001), a propensity-matched cohort (32 variables; HR, 0.52 [95% CI, 0.35-0.79], P = .002), and an inverse probability-weighted analysis (HR, 0.66 [95% CI, 0.52-0.83], P < .001), associated with a 5-year reduction in mortality of 52.6% (P < .001). Similar results were observed in relative reduction in mortality following early surgery in the subset with class II triggers (59.3 after 5 years, P = .002). Long-term heart failure risk was also lower with early surgery (7% vs 23% at 10 years, P < .001), which was confirmed in risk-adjusted models (HR, 0.29 [95% CI, 0.19-0.43], P < .001), a propensity-matched cohort (HR, 0.44 [95% CI, 0.26-0.76], P = .003), and in the inverse probability-weighted analysis (HR, 0.51 [95% CI, 0.36-0.72], P < .001). Reduction in late-onset atrial fibrillation was not observed (HR, 0.85 [95% CI, 0.64-1.13], P = .26).</AbstractText>Among registry patients with mitral valve regurgitation due to flail mitral leaflets, performance of early mitral surgery compared with initial medical management was associated with greater long-term survival and a lower risk of heart failure, with no difference in new-onset atrial fibrillation.</AbstractText> |
12,765 | Effect of engineered anisotropy on the susceptibility of human pluripotent stem cell-derived ventricular cardiomyocytes to arrhythmias. | Human (h) pluripotent stem cells (PSC) such as embryonic stem cells (ESC) can be directed into cardiomyocytes (CMs), representing a potential unlimited cell source for disease modeling, cardiotoxicity screening and myocardial repair. Although the electrophysiology of single hESC-CMs is now better defined, their multi-cellular arrhythmogenicity has not been thoroughly assessed due to the lack of a suitable experimental platform. Indeed, the generation of ventricular (V) fibrillation requires single-cell triggers as well as sustained multi-cellular reentrant events. Although native VCMs are aligned in a highly organized fashion such that electrical conduction is anisotropic for coordinated contractions, hESC-derived CM (hESC-CM) clusters are heterogenous and randomly organized, and therefore not representative of native conditions. Here, we reported that engineered alignment of hESC-VCMs on biomimetic grooves uniquely led to physiologically relevant responses. Aligned but not isotropic control preparations showed distinct longitudinal (L) and transverse (T) conduction velocities (CV), resembling the native human V anisotropic ratio (AR = LCV/TCV = 1.8-2.0). Importantly, the total incidence of spontaneous and inducible arrhythmias significantly reduced from 57% in controls to 17-23% of aligned preparations, thereby providing a physiological baseline for assessing arrhythmogenicity. As such, promotion of pro-arrhythmic effect (e.g., spatial dispersion by β adrenergic stimulation) could be better predicted. Mechanistically, such anisotropy-induced electrical stability was not due to maturation of the cellular properties of hESC-VCMs but their physical arrangement. In conclusion, not only do functional anisotropic hESC-VCMs engineered by multi-scale topography represent a more accurate model for efficacious drug discovery and development as well as arrhythmogenicity screening (of pharmacological and genetic factors), but our approach may also lead to future transplantable prototypes with improved efficacy and safety against arrhythmias. |
12,766 | The relationship between atrial septal aneurysm and autonomic dysfunction. | Systemic thromboembolism is a serious, major complication in patients with an atrial septal aneurysm (ASA). Atrial dysfunction resulting from paroxysmal atrial fibrillation is more common in patients with ASA than in the general population. The autonomic nervous system plays an important role in the initiation of atrial fibrillation.</AbstractText>To investigate autonomic function and its impact on ventricular and atrial arrhythmia in a group of ASA patients compared with a control group of healthy volunteers.</AbstractText>The study group consisted of 40 patients with ASA; the control group consisted of 30 age-, sex- and body mass index-matched healthy volunteers. All patients and control subjects underwent echocardiographic examination. Autonomic function was assessed by determining heart rate variability (HRV) indexes.</AbstractText>HRV time and frequency domain indexes were lower in patients with ASA compared with healthy controls (188±32 ms(2) and 323±42 ms(2) for low-frequency HRV; 195±39 ms(2) and 377±43 ms(2) for high-frequency HRV; P<0.001 for all). Statistically significant differences with respect to other HRV indexes were also found between the two groups.</AbstractText>ASA appears to be associated with cardiac autonomic dysfunction; however, the mechanisms of this association are not known in detail.</AbstractText> |
12,767 | Electrocardiogram as a screening tool in the general population: a strategic review. | Sudden cardiac death (SCD) is a major public health concern, accounting for 400,000 deaths in the US each year. Clinical and autopsy studies have consistently demonstrated a predominant, common pathophysiology in Western populations, showing that the most common electrophysiological mechanism of SCD is ventricular fibrillation, and the most common pathologic substrate is coronary heart disease (CHD). In about half of SCD cases, death is the first clinical manifestation of CHD. Yet risk factors of SCD early in the natural history of conditions predisposing SCD have not been fully identified, and SCD risk stratification strategy in the general population has not been developed. ECG is an easily available, non-expensive and non-invasive tool, which carries valuable information on electrophysiological properties of the heart. However, traditional analysis of ECG includes very limited assessment of the arrhythmogenic substrate. In this review rationale for development of ECG SCD risk score for screening in the general population is discussed. |
12,768 | Atrial fibrillation with rapid ventricular response resulting from low-voltage electrical injury. | Cardiac dysrhythmias after electrical injury have been reported previously, however, atrial fibrillation after low-voltage electrical injury is extremely rare. We present a case of atrial fibrillation with rapid ventricular response resulting from a low-voltage electrical injury.</AbstractText>A 24-year-old active duty Navy sailor presented to the emergency department after an electrical shock from a 440-V furnace. He experienced severe pain in both hands and a racing sensation in his chest. He denied other symptoms. An electrocardiogram was performed demonstrating atrial fibrillation with a rapid ventricular response (132 beats/min). After analgesia and sedation, synchronized cardioversion (100 J) was performed with complete resolution of cardiac symptoms and restoration of normal sinus rhythm (75 beats/min). Cutaneous wounds were bandaged and the patient was discharged with cardiology follow-up. At follow-up, the patient reported no symptoms and an echocardiogram revealed no structural abnormalities.</AbstractText>Atrial fibrillation in the setting of electrical injury is rarely reported in the published medical literature. In patients without history suggestive of cardiac structural abnormalities, synchronized cardioversion is a potential option for restoration of normal sinus rhythm and resolution of symptoms after electrical injury-induced atrial fibrillation with rapid ventricular response.</AbstractText>Published by Elsevier Inc.</CopyrightInformation> |
12,769 | "Rescue" ablation of electrical storm in arrhythmogenic right ventricular cardiomyopathy in pregnancy. | Radiofrequency ablation (RFCA) became a treatment of choice in patients with recurrent ventricular tachycardia, ventricular fibrillation, and appropriate interventions of implanted cardioverter-defibrillator (ICD), however, electrical storm (ES) ablation in a pregnant woman has not yet been reported.</AbstractText>We describe a case of a successful rescue ablation of recurrent ES in a 26-year-old Caucasian woman during her first pregnancy (23rd week). The arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) was diagnosed 3 years earlier and several drugs as well as 2 ablations failed to control recurrences of ventricular tachycardia. RFCA was performed on the day of the third electric storm. The use of electroanatomic mapping allowed very low X-ray exposure, and after applications in the right ventricular outflow tract, arrhythmia disappeared. Three months after ablation, a healthy girl was delivered without any complications. During twelve-month follow-up there was no recurrence of ventricular tachycardia or ICD interventions.</AbstractText>This case documents the first successful RFCA during ES due to recurrent unstable ventricular arrhythmias in a patient with ARVD/C in pregnancy. Current guidelines recommend metoprolol, sotalol and intravenous amiodarone for prevention of recurrent ventricular tachycardia in pregnancy, however, RFCA should be considered as a therapeutic option in selected cases. The use of 3D navigating system and near zero X-ray approach is associated with minimal radiation exposure for mother and fetus as well as low risk of procedural complication.</AbstractText> |
12,770 | Exercise training and implantable cardioverter-defibrillator shocks in patients with heart failure: results from HF-ACTION (Heart Failure and A Controlled Trial Investigating Outcomes of Exercise TraiNing). | The purpose of this study was to determine whether exercise training is associated with an increased risk of implantable cardioverter-defibrillator (ICD) therapy in patients with heart failure (HF).</AbstractText>Few data are available regarding the safety of exercise training in patients with ICDs and HF.</AbstractText>HF-ACTION (Heart Failure and A Controlled Trial Investigating Outcomes of Exercise TraiNing) randomized 2,331 outpatients with HF and an ejection fraction (EF) ≤35% to exercise training or usual care. Cox proportional hazards modeling was used to examine the relationship between exercise training and ICD shocks.</AbstractText>We identified 1,053 patients (45%) with an ICD at baseline who were randomized to exercise training (n = 546) or usual care (n = 507). Median age was 61 years old, and median EF was 24%. Over a median of 2.2 years of follow-up, 20% (n = 108) of the exercise patients had a shock versus 22% (n = 113) of the control patients. A history of sustained ventricular tachycardia/fibrillation (hazard ratio [HR]: 1.93 [95% confidence interval (CI): 1.47 to 2.54]), previous atrial fibrillation/flutter (HR: 1.63 [95% CI: 1.22 to 2.18]), exercise-induced dysrhythmia (HR: 1.67 [95% CI: 1.23 to 2.26]), lower diastolic blood pressure (HR for 5-mm Hg decrease <60: 1.35 [95% CI: 1.12 to 1.61]), and nonwhite race (HR: 1.50 [95% CI: 1.13 to 2.00]) were associated with an increased risk of ICD shocks. Exercise training was not associated with the occurrence of ICD shocks (HR: 0.90 [95% CI: 0.69 to 1.18], p = 0.45). The presence of an ICD was not associated with the primary efficacy composite endpoint of death or hospitalization (HR: 0.99 [95% CI: 0.86 to 1.14], p = 0.90).</AbstractText>We found no evidence of increased ICD shocks in patients with HF and reduced left ventricular function who underwent exercise training. Exercise therapy should not be prohibited in ICD recipients with HF. (Exercise Training Program to Improve Clinical Outcomes in Individuals With Congestive Heart Failure; NCT00047437)</AbstractText> |
12,771 | Cardiac arrest at exercise facilities: implications for placement of automated external defibrillators. | This study sought to characterize the relative frequency, care, and survival of sudden cardiac arrest in traditional indoor exercise facilities, alternative indoor exercise sites, and other indoor sites.</AbstractText>Little is known about the relative frequency of sudden cardiac arrest at traditional indoor exercise facilities versus other indoor locations where people engage in exercise or about the survival at these sites in comparison with other indoor locations.</AbstractText>We examined every public indoor sudden cardiac arrest in Seattle and King County from 1996 to 2008 and categorized each event as occurring at a traditional exercise center, an alternative exercise site, or a public indoor location not used for exercise. Arrests were further defined by the classification of the site, activity performed, demographics, characteristics of treatment, and survival. For some location types, annualized site incident rates of cardiac arrests were calculated.</AbstractText>We analyzed 849 arrests, with 52 at traditional centers, 84 at alternative exercise sites, and 713 at sites not associated with exercise. The site incident rates of arrests at indoor tennis facilities, indoor ice arenas, and bowling alleys were higher than at traditional fitness centers. Survival to hospital discharge was greater at exercise sites (56% at traditional and 45% at alternative) than at other public indoor locations (34%; p = 0.001).</AbstractText>We observed a higher rate of cardiac arrests at some alternative exercise facilities than at traditional exercise sites. Survival was higher at exercise sites than at nonexercise indoor sites. These data have important implications for automated external defibrillator placement.</AbstractText>Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
12,772 | Inhibition of I(f) in the atrioventricular node as a mechanism for dronedarone's reduction in ventricular rate during atrial fibrillation. | In clinical trials, dronedarone lowers ventricular rate during atrial fibrillation (AF). This agent was recently demonstrated to inhibit If in the sinoatrial node.</AbstractText>The purpose of this study was to examine whether dronedarone inhibits If at the atrioventricular (AV) node to reduce ventricular rate during AF by slowing conduction at the AV node.</AbstractText>We studied the effects of dronedarone (1.0 mg/kg IV bolus) before and after administration of the If inhibitor ivabradine (0.5 mg/kg IV). Ventricular rate, mean arterial pressure, dominant frequency of AF, PR and QT intervals, and atrial (AERP) and ventricular effective refractory periods (VERP) were measured during atrial pacing at 150 bpm in an anesthetized pig model of AF induced by intrapericardial acetylcholine and burst pacing.</AbstractText>Dronedarone reduced ventricular rate during AF by 22.1% (from 213 ± 11.1 bpm to 166 ± 8.3 bpm, P = .01) and increased PR interval by 8.7% (from 173 ± 5.6 ms to 188 ± 5.2 ms, P = .001), QT interval by 3.3% (from 272 ± 6.2 ms to 281 ± 4.9 ms, P = .05), and AERP and VERP by 6.2% and 11.7%, respectively. All other parameters remained unchanged. Dronedarone plasma levels were low (29 ± 4 nM), and concentration in tissue was 15- to 21-fold higher than in plasma. Ivabradine reduced ventricular rate during AF by 39.5% (from 200 ± 14.6 bpm to 121 ± 20.1 bpm, P = .005) and increased PR interval by 20.4% (from 157 ± 9.5 ms to 189 ± 7.4 ms, P <.05). Administration of dronedarone after ivabradine did not further alter these endpoints.</AbstractText>Dronedarone, which is concentrated in myocardial tissue, reduces ventricular rate during AF by slowing AV conduction. Absence of this effect after ivabradine administration implicates If inhibition as a mechanism.</AbstractText>© 2013 Heart Rhythm Society. All rights reserved.</CopyrightInformation> |
12,773 | Low-amplitude, left vagus nerve stimulation significantly attenuates ventricular dysfunction and infarct size through prevention of mitochondrial dysfunction during acute ischemia-reperfusion injury. | Right cervical vagus nerve stimulation (VNS) provides cardioprotective effects against acute ischemia-reperfusion injury in small animals. However, inconsistent findings have been reported.</AbstractText>To determine whether low-amplitude, left cervical VNS applied either intermittently or continuously imparts cardioprotection against acute ischemia-reperfusion injury.</AbstractText>Thirty-two isoflurane-anesthetized swine (25-30 kg) were randomized into 4 groups: control (sham operated, no VNS), continuous-VNS (C-VNS; 3.5 mA, 20 Hz), intermittent-VNS (I-VNS; continuously recurring cycles of 21-second ON, 30-second OFF), and I-VNS + atropine (1 mg/kg). Left cervical VNS was applied immediately after left anterior descending artery occlusion (60 minutes) and continued until the end of reperfusion (120 minutes). The ischemic and nonischemic myocardium was harvested for cardiac mitochondrial function assessment.</AbstractText>VNS significantly reduced infarct size, improved ventricular function, decreased ventricular fibrillation episodes, and attenuated cardiac mitochondrial reactive oxygen species production, depolarization, and swelling, compared with the control group. However, I-VNS produced the most profound cardioprotective effects, particularly infarct size reduction and decreased ventricular fibrillation episodes, compared to both I-VNS + atropine and C-VNS. These beneficial effects of VNS were abolished by atropine.</AbstractText>During ischemia-reperfusion injury, both C-VNS and I-VNS provide significant cardioprotective effects compared with I-VNS + atropine. These beneficial effects were abolished by muscarinic blockade, suggesting the importance of muscarinic receptor modulation during VNS. The protective effects of VNS could be due to its protection of mitochondrial function during ischemia-reperfusion.</AbstractText>© 2013 Heart Rhythm Society. All rights reserved.</CopyrightInformation> |
12,774 | Association between obesity and postoperative atrial fibrillation in patients undergoing cardiac operations: a systematic review and meta-analysis. | In a systematic review and random-effects meta-analysis, we evaluated whether obesity is associated with postoperative atrial fibrillation (POAF) in patients undergoing cardiac operations. We selected 18 observational studies until December 2011 that excluded patients with preoperative AF (n=36,147). Obese patients had a modest higher risk of POAF compared with nonobese (odds ratio, 1.12; 95% confidence interval, 1.04 to 1.21; p=0.002). The association between obesity and POAF did not vary substantially by type of cardiac operation, study design, or year of publication. POAF was significantly associated with a higher risk of stroke, respiratory failure, and operative death. |
12,775 | Severe sepsis and septic shock in patients with pre-existing non-cardiac pulmonary hypertension: contemporary management and outcomes. | To review treatment and outcomes of septic shock in patients with pulmonary hypertension (PH) managed at a tertiary care institution.</AbstractText><AbstractText Label="DESIGN, SETTING AND PATIENTS" NlmCategory="METHODS">We identified consecutive patients with non-cardiac PH (non-Group 2 in the World Health Organization classification) who were treated for septic shock in four intensive care units at a tertiary care institution between July 2004 and July 2007. Patients with a left ventricular ejection fraction < 50%, diastolic dysfunction, pericardial effusion or significant valve disease were excluded. Descriptive statistics were used to analyse the data.</AbstractText>Hospital mortality, duration of vasopressor and ventilatory support, length of hospital and ICU stay.</AbstractText>The final group for analysis comprised 82 patients. The major causes of PH were chronic obstructive pulmonary disease, interstitial lung disease and portopulmonary hypertension. PH was mild in 46 patients (56%), moderate in 21 (26%) and severe in 15 (18%). Vasopressor treatment was initiated in 69 patients (84%) within the first 48 hours: noradrenaline was most commonly used (53 patients, 65%), and 51 patients (62%) were treated with more than one agent. Sixty-seven patients (82%) were mechanically ventilated, and 33 (40%) required renal replacement therapy. Fortythree patients (52%) survived to hospital discharge; 23 (28%) remained alive at 1 year. Hospital mortality increased with severity of PH: 28% in mild, 67% in moderate and 80% in severe PH. Nonsurvivors were more likely to have plateau pressures beyond 30 cm H(2)O while mechanically ventilated within the first 48 hours in the ICU (56% v 29%, P = 0.03), to develop atrial fibrillation (AF) (46% v 12%, P < 0.001), and to require longer vasopressor support (mean, 5.3 v 2.6 days, P = 0.003). In a multivariate logistic regression analysis, severity of PH (odds ratio [OR], 1.55; 95% CI, 1.04-2.46; P = 0.04), new-onset AF (OR, 6.51; 95% CI, 2.24-22.07; P < 0.001) and longer duration of vasopressor support (OR, 1.15; 95% CI, 1.03-1.34; P = 0.04) were associated with increased hospital mortality.</AbstractText>The severity of PH, new-onset AF, and longer vasopressor support were associated with poor outcomes in patients with PH who developed severe sepsis and septic shock.</AbstractText> |
12,776 | Curvature analysis of cardiac excitation wavefronts. | We present the Spiral Classification Algorithm (SCA), a fast and accurate algorithm for classifying electrical spiral waves and their associated breakup in cardiac tissues. The classification performed by SCA is an essential component of the detection and analysis of various cardiac arrhythmic disorders, including ventricular tachycardia and fibrillation. Given a digitized frame of a propagating wave, SCA constructs a highly accurate representation of the front and the back of the wave, piecewise interpolates this representation with cubic splines, and subjects the result to an accurate curvature analysis. This analysis is more comprehensive than methods based on spiral-tip tracking, as it considers the entire wave front and back. To increase the smoothness of the resulting symbolic representation, the SCA uses weighted overlapping of adjacent segments which increases the smoothness at join points. SCA has been applied to a number of representative types of spiral waves, and, for each type, a distinct curvature evolution in time (signature) has been identified. Distinct signatures have also been identified for spiral breakup. These results represent a significant first step in automatically determining parameter ranges for which a computational cardiac-cell network accurately reproduces a particular kind of cardiac arrhythmia, such as ventricular fibrillation. |
12,777 | A review of the confirmation algorithm and related timing cycles of St. Jude ICDs. | The confirmation algorithm of implantable cardioverter-defibrillators (ICDs) functioning in the uncommitted mode verifies the presence of a continuing tachyarrhythmia during or following charging of the capacitor. Confirmation is usually applied in relation to the first shock. The details of the normal reconfirmation process of St. Jude ICDs and its role in delayed shock delivery or other abnormalities have received relatively little attention. This review describes the confirmation process of St. Jude ICDs and provides an illustrative clinical example of delayed shock as a result of a pacing or sensing lead fracture. The fundamental timing cycles of St. Jude ICDs are also reviewed to facilitate understanding of the problems related to the confirmation process. |
12,778 | Value of early cardiovascular magnetic resonance for the prediction of adverse arrhythmic cardiac events after a first noncomplicated ST-segment-elevation myocardial infarction. | Infarct size (IS) determined by cardiac magnetic resonance (CMR) has proven an additional value, on top of left ventricular ejection fraction (LVEF), in prediction of adverse arrhythmic cardiac events (AACEs) in chronic ischemic heart disease. Its value soon after an acute ST-segment-elevation myocardial infarction remains unknown. Our aim was to determine whether early CMR can improve AACE risk prediction after acute ST-segment-elevation myocardial infarction.</AbstractText>Patients admitted for a first noncomplicated ST-segment-elevation myocardial infarction were prospectively followed up. A total of 440 patients were included. All of them underwent CMR 1 week after admission. CMR-derived LVEF and IS (grams per meter squared) were quantified. AACEs included postdischarge sudden death, sustained ventricular tachycardia, and ventricular fibrillation either documented on ECG or recorded via an implantable cardioverter-defibrillator. Within a median follow-up of 2 years, 11 AACEs (2.5%) were detected: 5 sudden deaths (1.1%) and 6 spontaneous ventricular tachycardia/ventricular fibrillation. In the whole group, AACEs associated with more depressed LVEF (adjusted hazard ratio [95% confidence interval], 0.90 [0.83-0.97]; P<0.01) and larger IS (adjusted hazard ratio [95% confidence interval], 1.06 [1.01-1.12]; P=0.01). According to the corresponding area under the receiver operating characteristic curve, LVEF ≤36% and IS ≥23.5 g/m(2) best predicted AACEs. The vast majority of AACEs (10/11) occurred in patients with simultaneous depressed LVEF ≤36% and IS ≥23.5 g/m(2) (n=39).</AbstractText>In the era of reperfusion therapies, occurrence of AACEs in patients with an in-hospital noncomplicated first ST-segment-elevation myocardial infarction is low. In this setting, assessment of an early CMR-derived IS could be useful for further optimization of AACE risk prediction.</AbstractText> |
12,779 | Storms of ventricular fibrillation responsive to isoproterenol in an idiopathic ventricular fibrillation patient demonstrating complete right bundle branch block. | A 45-year-old male was admitted to our hospital after successful resuscitation of cardiac arrest. Ventricular fibrillation (VF) had occurred during breakfast and was defibrillated by an automated external defibrillator operated by emergency medical service staff. On admission, his ECG demonstrated complete right bundle branch block as the sole abnormality. Intensive examination could not detect any structural disease leading to a diagnosis of idiopathic VF and implantation of an ICD. VF storm occurred one month after hospital discharge and beta-blocker, amiodarone, and sedative administration had no effect on VF. Likewise, catheter ablation for triggering premature ventricular beats failed to control the VF storm. The VF storm then subsided in the following weeks and the patient was discharged on amiodarone. A half month later VF storm recurred and the patient was admitted again. This time, isoproterenol infusion was effective in suppressing VF, and thereafter the patient was administered bepridil and followed up without recurrence of VF for 1.5 years. From these beneficial effects, the VF of the patient was suggested to share common arrhythmogenic characteristics to those of Brugada syndrome or J-wave associated VF. |
12,780 | Methadone-induced Torsades de pointes. | Torsades de pointes is a polymorphic ventricular tachycardia that can quickly evolve into ventricular fibrillation and sudden death. This arrhythmia often occurs secondary to medication- induced cardiac repolarization dysfunction with resultant prolonged QTc interval on ECG. Numerous medications can predispose patients to this deadly tachycardia. We report a case of methadone-induced Torsades de pointes complicated by ventricular fibrillation and cardiac arrest. Through rapid taper of methadone, the patient's ECG normalized, allowing for safe discharge. This clinical vignette highlights the importance of close monitoring of patient medications. Performing periodic ECGs with prompt removal of offending agent when repolarization abnormalities are appreciated is ideal. Most importantly, as the vast array of medications continues to grow, it is imperative that clinicians are cognizant of side effects and tailor treatment accordingly. |
12,781 | Amiodarone inhibits apamin-sensitive potassium currents. | Apamin sensitive potassium current (I KAS), carried by the type 2 small conductance Ca(2+)-activated potassium (SK2) channels, plays an important role in post-shock action potential duration (APD) shortening and recurrent spontaneous ventricular fibrillation (VF) in failing ventricles.</AbstractText>To test the hypothesis that amiodarone inhibits I KAS in human embryonic kidney 293 (HEK-293) cells.</AbstractText>We used the patch-clamp technique to study I KAS in HEK-293 cells transiently expressing human SK2 before and after amiodarone administration.</AbstractText>Amiodarone inhibited IKAS in a dose-dependent manner (IC50, 2.67 ± 0.25 µM with 1 µM intrapipette Ca(2+)). Maximal inhibition was observed with 50 µM amiodarone which inhibited 85.6 ± 3.1% of IKAS induced with 1 µM intrapipette Ca(2+) (n = 3). IKAS inhibition by amiodarone was not voltage-dependent, but was Ca(2+)-dependent: 30 µM amiodarone inhibited 81.5±1.9% of I KAS induced with 1 µM Ca(2+) (n = 4), and 16.4±4.9% with 250 nM Ca(2+) (n = 5). Desethylamiodarone, a major metabolite of amiodarone, also exerts voltage-independent but Ca(2+) dependent inhibition of I KAS.</AbstractText>Both amiodarone and desethylamiodarone inhibit I KAS at therapeutic concentrations. The inhibition is independent of time and voltage, but is dependent on the intracellular Ca(2+) concentration. SK2 current inhibition may in part underlie amiodarone's effects in preventing electrical storm in failing ventricles.</AbstractText> |
12,782 | Early mortality in prophylactic implantable cardioverter-defibrillator recipients: development and validation of a clinical risk score. | To reduce sudden cardiac death, implantable cardioverter-defibrillators (ICDs) are indicated in patients with ischaemic and non-ischaemic dilated cardiomyopathy and a left ventricular ejection fraction (LVEF) ≤35%. Current guidelines do not recommend device therapy in patients with a life expectancy <1 year since benefit in these patients is low. In this study, we evaluated the incidence and predictors of early mortality (<1 year after implantation) in a consecutive primary prevention population.</AbstractText>Analysis was performed on a prediction and validation cohort. The primary endpoint was all-cause mortality at 1 year. The prediction cohort comprised 861 prophylactic ICD recipients with ischaemic cardiomyopathy or dilated cardiomyopathy from the Academic Medical Center (Amsterdam) and Thorax Center Twente (Enschede). Detailed clinical data were collected. After multivariate analysis, a risk score was developed based on age ≥75 years, LVEF ≤ 20%, history of atrial fibrillation, and estimated glomerular filtration rate (eGFR) ≤30 mL/min/1.73 m(2). Using these predictors, a low (≤1 factor), intermediate (2 factors), and high (≥3 factors) risk group could be identified with 1-year mortality of, respectively, 3.4, 10.9, and 38.9% (P< 0.01). Afterwards, the risk score was validated in 706 primary prevention patients from the Erasmus Medical Center (Rotterdam). One-year mortality was, respectively, 2.5, 13.2, and 46.3% (all P< 0.01).</AbstractText>A simple risk score based on age, LVEF, eGFR, and atrial fibrillation can identify patients at low, intermediate, and high risk for early mortality after ICD implantation. This may be helpful in the risk assessment of ICD candidates.</AbstractText> |
12,783 | The impact of haemodialysis on the outcomes of catheter ablation in patients with paroxysmal atrial fibrillation. | The outcomes of catheter ablation (CA) in patients with paroxysmal atrial fibrillation (PAF) who are undergoing haemodialysis (HD) have not been fully elucidated. This study aimed to determine the impact of HD on CA outcome in these patients.</AbstractText>We examined 1364 consecutive PAF patients (mean age, 61 ± 10 years) who underwent CA, including 32 (2.3%) patients undergoing HD. The patients undergoing HD had a significantly lower body mass index (P < 0.0001), higher CHADS2 score (P = 0.006), and higher prevalence of structural heart disease (P < 0.0001), hypertension (P = 0.002), and congestive heart failure (P = 0.02). Echocardiography indicated a larger left atrial diameter (P < 0.0001) and left ventricular diameter (P = 0.0002) in the HD patients. Haemodialysis was a significant predictor of AF recurrence (hazard ratio 2.56; 95% confidence interval 1.56-4.03; P = 0.0004) in the overall population. Sinus rhythm maintenance rates in the HD patients at 1, 3, and 5 years were 42.3, 37.6, and 19.7%, respectively, after the first procedure, and 64.7, 54.9, and 47.1%, respectively, after the final procedure (median, 2; range, 1-2 procedures); these rates were significantly lower than those in the non-HD patients (P < 0.0001). The 5-year survival rate was 78.1% in the HD patients.</AbstractText>Haemodialysis was significantly associated with AF recurrence after CA for PAF. However, an ∼50% success rate for sinus rhythm maintenance without antiarrhythmic drug therapy in HD patients suggested that CA could be an option for the treatment of AF.</AbstractText> |
12,784 | Surgical approach to intramyocardial administration of bone marrow stem cells in an animal model. | The aim of the study was to evaluate the surgical approach to intramyocardial (i.m.) injection of Bone Marrow Stem Cells (BMSCs) in a pre-clinical model and its complications.</AbstractText>In New Zealand rabbits an ischemia reperfusion injury lasting 20 min was induced by temporary ligation of anterior descending coronary artery during cardiac surgical procedure. Homologous BMSCs were isolated from the posterior iliac crest, cultured and re-suspended for injection. BMSC were injected at the peri-infarcted area and side effects were evaluated. A control group with myocardial infarction was treated with i.m. injections of saline, to evaluate possible side effects of injection. Comparison of ventricular premature contractions (VPC), ventricular tachycardia and ventricular fibrillation were recorded during surgery and after 7 and 21 days.</AbstractText>Seven rabbits developed intractable ventricular fibrillation during the experimental protocol, three during coronary ligation but before cell injections and four following i.m. injections. At day 7, hourly PVC were more frequent in the groups of animals that received i.m. injections of BMSCs (132 ± 19 beats) compared to saline injections. (54 ± 14).</AbstractText>Intramyocardial injections of BMSCs induced an electrical instability as shown by a high number of PVC as compared with intramyocardial injections of saline.</AbstractText> |
12,785 | [Clinical evaluation of intraoperative cardiac output measurement by a new arterial pressure waveform analysis method( FloTrac/Vigileo) in open heart surgery]. | We retrospectively evaluated the initial clinical experience of intraoperative cardiac output measurement by a new arterial pressure-based cardiac output (APCO:FloTrac/Vigileo) analysis in patients undergoing open heart surgery. Thirty-two patients (mean age 76.4, range 59 to 90)who underwent cardiac surgery under cardiopulmonary bypass( CPB) from July 2008 to September 2009 in our institute were enrolled in this study. There were 14 women and 18 men. The cardiac operations included 28 valve surgeries and 4 coronary artery bypass grafting. The APCO was introduced initially, then a continuous cardiac output (CCO:Swan-Ganz catheter) analysis system was established following the induction of anesthesia. The correlation of both cardiac output measurements was evaluated at 5 time points, T1:induction of anesthesia, T2:sternotomy, T3:after weaning from CPB, T4:closure of the chest, and T5:arrival at intensive care unit. There were no serious complications related to APCO and CCO. The correlation between APCO and CCO was evaluated by Bland-Altman plot analysis. The percentages of correlation between both groups were T1:81.2%, T2:78.1%, T3:59.4%, T4:62.5%, and T5:65.6%. A good correlation was shown in all 6 patients with atrial fibrillation at T1 and T2. No correlation was shown in the 3 patients with left ventricular( LV) dysfunction below LVEF 40%, 1 case at T3, all 3 cases at T4, and 2 cases at T5. Before the institution of CPB, 3 of the 6 at T1 and 3 of the 7 at T2 in whom no correlation was shown, had severe aortic valve insufficiency (AVI).From these results, APCO appears to be an acceptable device to evaluate the intraoperative cardiac output measurement compared with CCO, except in patients with LV dysfunction or AVI at some time points. Further studies will be necessary to elucidate the precise clinical evidence to assess the efficacy of this new analysis device. |
12,786 | Efficacy, safety, and outcomes of catheter ablation of atrial fibrillation in patients with heart failure with preserved ejection fraction. | This study sought to investigate the efficacy and safety of catheter ablation for atrial fibrillation (AF) in patients with heart failure with preserved ejection fraction (HFPEF).</AbstractText>AF is a precipitating factor for clinical deterioration of HFPEF.</AbstractText>Catheter ablation for AF was performed in a consecutive 74 patients with compensated HFPEF (left ventricular [LV] ejection fraction >50%). AF-free probability after catheter ablation and factors relating to maintenance of sinus rhythm were investigated. LV strain and strain rate were assessed by echocardiography at baseline and over 12 months after ablation.</AbstractText>During a 34 ± 16-month follow-up period, single- and multiple-procedure drug-free success rates were 27% (n = 20) and 45% (n = 33), respectively. Multiple procedures and pharmaceutically assisted success rate was 73% (n = 54). No major complications occurred during follow-up. Multivariate Cox regression analyses revealed that AF type (other than long-standing persistent AF) and lack of hypertension were independently associated with maintenance of sinus rhythm (hazard ratio [HR]: 1.81, 95% confidence interval [CI]: 1.03 to 3.17, p = 0.04; HR: 0.49, 95% CI: 0.24 to 0.96, p = 0.04, respectively). LV systolic indices (LV ejection fraction, LV strain/strain rate at systole) and diastolic indices (E/E', ratio of LV strain rate at diastole with early transmitral flow) were improved only in patients maintaining sinus rhythm at follow-up.</AbstractText>Our results suggest that AF can be effectively and safely treated with a composite of repeat procedures and pharmaceuticals in patients with HFPEF. However, the current study was a single-arm analysis; therefore, larger randomized control studies are needed to verify the benefit of AF ablation in this cohort.</AbstractText>Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
12,787 | Wearable cardioverter-defibrillator use in patients perceived to be at high risk early post-myocardial infarction. | The aim of this study was to describe usage of the wearable cardioverter-defibrillator (WCD) during mandated waiting periods following myocardial infarction (MI) for patients perceived to be at high risk for sudden cardiac arrest (SCA).</AbstractText>Current device guidelines and insurance coverage require waiting periods of either 40 days or 3 months before implanting a cardioverter-defibrillator post-myocardial infarction (MI), depending on whether or not acute revascularization was undertaken.</AbstractText>We assessed characteristics of and outcomes for patients who had a WCD prescribed in the first 3 months post-MI. The WCD medical order registry was searched for patients who were coded as having had a "recent MI with ejection fraction ≤35%" or given an International Classification of Diseases, Ninth Revision 410.xx diagnostic code (acute MI), and then matched to device-recorded data.</AbstractText>Between September 2005 and July 2011, 8,453 unique patients (age 62.7 ± 12.7 years, 73% male) matched study criteria. A total of 133 patients (1.6%) received 309 appropriate shocks. Of these patients, 91% were resuscitated from a ventricular arrhythmia. For shocked patients, the left ventricular ejection fraction (LVEF) was ≤30% in 106, 30% to 35% in 17, >36% in 8, and not reported in 2 patients. Of the 38% of patients not revascularized, 84% had a LVEF ≤30%; of the 62% of patients revascularized, 77% had a LVEF ≤30%. The median time from the index MI to WCD therapy was 16 days. Of the treated patients, 75% received treatment in the first month, and 96% within the first 3 months of use. Shock success resulting in survival was 84% in nonrevascularized and 95% in revascularized patients.</AbstractText>During the 40-day and 3-month waiting periods in patients post-MI, the WCD successfully treated SCA in 1.4%, and the risk was highest in the first month of WCD use. The WCD may benefit individual patients selected for high risk of SCA early post-MI.</AbstractText>Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
12,788 | Ventricular fibrillation associated with J-wave manifestation following pericarditis after catheter ablation for paroxysmal atrial fibrillation. | We present a patient with ventricular fibrillation (VF) associated with J-wave manifestation following pericarditis after catheter ablation of paroxysmal atrial fibrillation (AF). The premature ventricular contraction induced VF with J-waves in the inferior leads 2 days after the procedure. The patient's juvenile onset of AF and a family history of sudden cardiac death strongly suggested an underlying hereditable channelopathy. The late gadolinium enhancement in the posterior wall, viewed by cardiac magnetic resonance imaging, matched the leads of the J-waves. VF might develop in juvenile onset of AF especially in individuals with a family history of sudden cardiac death. |
12,789 | Idiopathic ventricular arrhythmias detected by an implantable loop recorder in a child with exercise-induced syncope. | Syncope is common in the general population. Despite extensive evaluation, including tilt-table testing and electrophysiologic studies, approximately 30% of cases of recurrent syncope remain unexplained. An implantable loop recorder can be used for diagnosis when recurrent syncope has an idiopathic cause. We present the case of a 9-year-old boy who had a history of recurrent, exercise-induced syncope. Results of physical examination and noninvasive diagnostic testing were inconclusive, and an electrophysiologic study revealed no inducible supraventricular or ventricular arrhythmias. Sixteen months after an implantable loop recorder was placed, the patient had a syncopal episode while swimming in a pool. Cardiopulmonary resuscitation was performed, and data from the loop recorder revealed polymorphic ventricular tachycardia and ventricular fibrillation. A cardioverter-defibrillator was subsequently implanted. Implantable loop recorders can play an important role in the diagnosis of life-threatening arrhythmias in children whose syncope is otherwise unexplained. |
12,790 | Coronary intervention on a moving target: a case report and procedural considerations. | Cardiac arrest carries a considerable mortality. Among survivors, the incidence of neurological dysfunction is considerable. Coronary disease is a major cause of cardiac arrest and early and effective resuscitation is related to outcome. We report for the first time a case of successful coronary angiography and primary percutaneous coronary intervention (PCI) during ongoing ventricular fibrillation (VF) supported by mechanical chest compressions following out-of-hospital ST-elevation myocardial infarction (STEMI) and VF cardiac arrest. It illustrates four novel findings permitted by the use of mechanical chest compressions: (1) that it provided a perfusion pressure that facilitated the act of coronary angiography during ongoing VF following out-of-hospital STEMI and VF arrest, which (2) in turn permitted successful primary PCI, with (3) maintained neurological function and survival despite 79 minutes between arrest and PCI, and (4) illustrates the practical considerations that one must consider for PCI during mechanical chest compressions. |
12,791 | Identification of clinical risk factors of atrial fibrillation in congestive heart failure. | Factors associated with the development of atrial fibrillation (AF) in general population have been described, but it is still unknown whether the same risk factors apply to heart failure (HF) patients. The aim of this study was to identify clinical factors related to various forms of AF in HF patients.</AbstractText>The clinical and echocardiographic characteristics were assessed in 155 HF patients: 50 with sinus rhythm, 52 with non-permanent AF, and 53 with permanent AF.</AbstractText>Multivariate logistic regression analysis showed that the increase in the NYHA class was an independent risk factor for both forms of AF. The occurrence of permanent AF in comparison to sinus rhythm group was independently associated with hs-C-reactive protein (CRP) elevation above 1 mg/dL (OR 1.87, 95% CI 1.05-3.35), left atrial dimension above 4 cm (OR 3.78, 95% CI 1.29-11.06) and tricuspid maximal pressure gradient elevation above 35 mm Hg (OR 5.01, 95% CI 1.38-18.27). The presence of coronary disease was independently associated with less frequent occurrence of permanent AF in comparison to sinus rhythm group (OR 0.21, 95% CI 0.06-0.67).</AbstractText>More advanced congestive HF was associated with presence of both types of AF. Non-ischemic etiology of HF and elevated CRP are independently associated with permanent AF compared to sinus rhythm. Left ventricular diastolic dysfunction indicators (increased tricuspid maximal pressure gradient and left artial dimension) are independently associated with permanent AF.</AbstractText> |
12,792 | An unusual intracardiac electrogram showing cause for false electrical discharge from an ICD. | We describe a rare case of inappropriate implantable cardioverter defibrillator (ICD) therapy due to false sensing of electromechanical interference from diathermy as 'ventricular fibrillation (VF)'. This occurred during surgical removal of sternal wires under general anaesthesia. Postsurgical interrogation of ICD revealed the intracardiac electrogram showing the mechanical interference sensed as 'VF' by ICD and subsequent shock delivery. |
12,793 | Cellular mechanisms underlying the effects of milrinone and cilostazol to suppress arrhythmogenesis associated with Brugada syndrome. | Brugada syndrome is an inherited disease associated with vulnerability to ventricular tachycardia and sudden cardiac death in young adults. Milrinone and cilostazol, oral phosphodiesterase (PDE) type III inhibitors, have been shown to increase L-type calcium channel current (ICa) and modestly increase heart rate by elevating the level of intracellular cyclic adenosine monophosphate.</AbstractText>To examine the effectiveness of these PDE inhibitors to suppress arrhythmogenesis in an experimental model of Brugada syndrome.</AbstractText>Action potential (AP) and electrocardiographic recordings were obtained from epicardial and endocardial sites of coronary-perfused canine right ventricular wedge preparations. The Ito agonist NS5806 (5 μM) and Ca(2+) channel blocker verapamil (2 μM) were used to pharmacologically mimic Brugada phenotype.</AbstractText>The combination induced all-or-none repolarization at some epicardial sites but not others, leading to ST-segment elevation as well as an increase in both epicardial and transmural dispersion of repolarization. Under these conditions, phase 2 reentry developed as the epicardial AP dome propagated from sites where it was maintained to sites at which it was lost, generating closely coupled extrasystoles and ventricular tachycardia. The addition of the PDE inhibitor milrinone (2.5 μM) or cilostazol (5-10 μM) to the coronary perfusate restored the epicardial AP dome, reduced dispersion, and abolished phase 2 reentry-induced extrasystoles and ventricular tachycardia.</AbstractText>Our study identifies milrinone as a more potent alternative to cilostazol for reversing the repolarization defects responsible for the electrocardiographic and arrhythmic manifestations of Brugada syndrome. Both drugs normalize ST-segment elevation and suppress arrhythmogenesis in experimental models of Brugada syndrome.</AbstractText>© 2013 Heart Rhythm Society. All rights reserved.</CopyrightInformation> |
12,794 | Robotics in cardiac surgery: past, present, and future. | Robotic cardiac operations evolved from minimally invasive operations and offer similar theoretical benefits, including less pain, shorter length of stay, improved cosmesis, and quicker return to preoperative level of functional activity. The additional benefits offered by robotic surgical systems include improved dexterity and degrees of freedom, tremor-free movements, ambidexterity, and the avoidance of the fulcrum effect that is intrinsic when using long-shaft endoscopic instruments. Also, optics and operative visualization are vastly improved compared with direct vision and traditional videoscopes. Robotic systems have been utilized successfully to perform complex mitral valve repairs, coronary revascularization, atrial fibrillation ablation, intracardiac tumor resections, atrial septal defect closures, and left ventricular lead implantation. The history and evolution of these procedures, as well as the present status and future directions of robotic cardiac surgery, are presented in this review. |
12,795 | Cardiogenic pulmonary oedema: alarmingly poor long term prognosis. Analysis of risk factors. | Acute heart failure (AHF) is a life-threatening condition associated with poor prognosis.</AbstractText>To investigate the long term prognosis and identify prognostic factors among patients who were discharged after an episode of cardiogenic pulmonary oedema.</AbstractText>We enrolled 84 patients (M: 56%, n = 47) who were discharged with cardiogenic pulmonary oedema as a diagnosis. Clinical, biochemical and echocardiographic variables were collected and analysed. The completeness of two- and five-year follow-up was 100% and 96%, respectively.</AbstractText>The median (IQR) age was 74 years (64-81), left ventricular ejection fraction was 35% (27-45), blood pressure on admission was 140/90 mm Hg (115-180/70-100), estimated glomerular filtration rate was 60 mL/min/1.73 m2 (45-73). Forty per cent (n = 34) of the patients had a history of atrial fibrillation (AF), however, AF was directly involved with pulmonary oedema only in 4% (n = 3) of the cases. Acute myocardial infarction (AMI) accounted for 34% (n = 29) of all the causes of pulmonary oedema and was associated with a better two-year prognosis compared to other causes of pulmonary oedema (p = 0.018). Two- and five-year mortality was 45% (n = 38) and 72% (n = 58), respectively. Co-morbidities were common. Ischaemic heart disease and arterial hypertension were present in 83% and 70% of the patients, respectively. Multivariable analysis identified increased left ventricular mass (RR 3.609, 95% CI 1.235-10.547, p = 0.017) and treatment with long-acting vasodilator drugs (LAVDs) (RR 4.881, 95% CI 1.618-14.727, p = 0.004) as independent negative prognostic factors, whereas in-hospital therapy with beta-blockers created a distinctly protective effect (RR 0.123, 95% CI 0.033-0.457, p = 0.002) in the two-year follow-up. Five-year mortality was independently associated with older age (RR 1.08, 95% CI 1.02-1.14, p = 0.005) and treatment with LAVDs (RR 6.4, 95% CI 1.47-28.14, p = 0.012), while percutaneous coronary intervention (RR 0.17, 95% CI 0.05-0.58, p = 0.004) significantly decreased the risk.</AbstractText>AHF is a heterogeneous syndrome with a very high remote mortality. LAVDs administered during the hospital stay as well as older age on admission correlate with higher long-term overall mortality. In the age of percutaneous coronary intervention, AMI aetiology of pulmonary oedema is no longer a negative prognostic factor for the long-term prognosis.</AbstractText> |
12,796 | Detection of a spontaneous pulse in photoplethysmograms during automated cardiopulmonary resuscitation in a porcine model. | Reliable, non-invasive detection of return of spontaneous circulation (ROSC) with minimal interruptions to chest compressions would be valuable for high-quality cardiopulmonary resuscitation (CPR). We investigated the potential of photoplethysmography (PPG) to detect the presence of a spontaneous pulse during automated CPR in an animal study.</AbstractText>Twelve anesthetized pigs were instrumented to monitor circulatory and respiratory parameters. Here we present the simultaneously recorded PPG and arterial blood pressure (ABP) signals. Ventricular fibrillation was induced, followed by 20 min of automated CPR and subsequent defibrillation. After defibrillation, pediatric-guidelines-style life support was given in cycles of 2 min. PPG and ABP waveforms were recorded during all stages of the protocol. Raw PPG waveforms were acquired with a custom-built photoplethysmograph controlling a commercial reflectance pulse oximetry probe attached to the nose. ABP was measured in the aorta.</AbstractText>In nine animals ROSC was achieved. Throughout the protocol, PPG and ABP frequency content showed strong resemblance. We demonstrate that (1) the PPG waveform allows for the detection of a spontaneous pulse during ventilation pauses, and that (2) frequency analysis of the PPG waveform allows for the detection of a spontaneous pulse and the determination of the pulse rate, even during ongoing chest compressions, if the pulse and compression rates are sufficiently distinct.</AbstractText>These results demonstrate the potential of PPG as a non-invasive means to detect pulse presence or absence, as well as pulse rate during CPR.</AbstractText>Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
12,797 | [Early cardiovascular complications post lung transplantation]. | To observe the early cardiovascular complications of patients underwent lung transplantation.</AbstractText>The clinical records of 73 patients who underwent lung transplantation in Wuxi People's Hospital from September 2002 to September of 2010 were retrospectively analyzed. All patients were transferred to intensive care unit (ICU) after lung transplantation, received invasive monitoring (PICCO), mechanical ventilation, immunosuppressive therapy and measures to prevent ischemic reperfusion injury. The early cardiovascular complications after lung transplantation up to discharge from hospital were observed.</AbstractText>The postoperative mortality was 20.5% (15/73) within 30 days after surgery. Five patients died of cardiovascular reasons including 2 cases of pulmonary embolism and 3 cases of ventricular fibrillation. Cardiovascular complications during the early post-operation period included: paroxysmal atrial fibrillation (19 cases, 26.0%) and persist atrial fibrillation (1 case, 1.4%); atrial fibrillation and atrial flutter in 3 cases and persistent atrial flutter in 1 patient; ventricular fibrillation (3 cases, 4.1%); paroxysmal supraventricular tachycardia (3 cases, 4.1%); ventricular tachycardia (2 cases, 2.7%); bundle branch block (8 cases, 11.0%); intraventricular block(4 cases, 5.5%); left ventricular heart failure(4 cases, 5.5%), right heart failure(6 cases, 8.2%); pulmonary embolism (2 cases, 2.7%), deep venous thrombosis (1 case, 1.4%).</AbstractText>Atrial fibrillation is the most common cardiovascular complication post lung transplantation. Pulmonary embolism and ventricular fibrillation are not common but related with high mortality rate post lung transplantation.</AbstractText> |
12,798 | Continuous monitoring of cardiac rhythms in left ventricular assist device patients. | Monitoring of cardiac rhythms is of major importance in the treatment of heart failure patients with left ventricular assist devices (LVADs) implanted. A continuous surveillance of these rhythms could improve out-of-hospital care in these patients. The aim of this study was to investigate cardiac rhythms using available pump data only. Datasets (n = 141) obtained in the normal ward, in the intensive care unit, and during bicycle ergometry were analyzed in 11 recipients of a continuous flow LVAD (59.1 ± 9.7 years; male 82%). Tachograms and arrhythmic patterns derived from the pump flow waveform, and a simultaneously recorded ECG were compared, as well as heart rate variability parameters such as: the average heart beat duration (RR interval), the standard deviation of the beat duration (SDNN), the root-mean-square of the difference of successive beat durations (RMSSD), and the number of pairs of adjacent beat duration differing by >50 ms divided by the number of all beats (pNN50). A very good agreement of cardiac rhythm parameters from the pump flow compared with ECG was found. Tachycardia, atrial fibrillation, and extrasystoles could be accurately identified from the tachograms derived from the pump flow. Also, Bland-Altman analysis comparing pump flow with ECG indicated a very small difference in average RR interval of 0.3 ± 1.0 ms, in SSDN of 0.5 ± 2.7 ms, in RMSSD of 1.0 ± 5.6 ms, and in pNN50 of 0.3 ± 1.0%. Continuous monitoring of cardiac rhythms from available pump data is possible. It has the potential to reduce the out-of-hospital diagnostic burden and to permit a more efficient adjustment of the level of mechanical support. |
12,799 | Impact of severe tricuspid regurgitation on long term survival. | Tricuspid regurgitation (TR) is a common echocardiographic finding, which often accompanies left sided valve disease. Data on mortality and morbidity in patients with severe TR are limited.</AbstractText>We sought to assess the outcome of patients with severe TR with the hypothesis that significant TR adversely impacts quality of life and survival, independent of pulmonary artery pressure (PAP) and left ventricular ejection fraction (LVEF).</AbstractText>Between 2002 and 2012, 358 consecutive patients (mean age of 54.67± 13.25years, 75.5% female) with severe TR based on history and transthoracic echocardiography (TTE) were enrolled. Patients with severe left sided valvular heart disease and congenital heart disease were excluded. The prevalence of heart failure symptoms, rehospitalization, and duration of hospitalization were evaluated. Survival was calculated according Kaplan Meier curve analysis.</AbstractText>Heart failure (50%) was the most cause of death. Mean years of survival from diagnosis of severe TR was 4.35±3.66, and mean years of survival from onset of symptom was 2.28±1.40. Ninety cases (25.1%) were admitted due to heart failure and through mean of 1.9±0.8 year- follow up (6-32month), 14% of all patients and 36.8% of patients with right heart failure rehospitalized. Atrial fibrillation was reported in 70.5% of patients.</AbstractText>There is a significant increased incidence of mortality, prolonged hospitalization, and rehospitalization in symptomatic patients with severe TR. Therefore, we recommend more aggressive approach toward TV repair or replacement in these patients regardless of PAP and systolic function.</AbstractText> |
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