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Objectives: Patients suffering from supraventricular tachycardia (SVT) require diagnostic or therapeutic intervention in a cardiac electrophysiology (EP) laboratory. Some anesthetic medications may adversely affect cardiac EP and conduction, altering the ability to induce the arrhythmia, and may have a negative impact on the ablation treatment. This prospective, randomized, pilot study was conducted in the cardiac EP laboratory of a tertiary care hospital with the aim to identify the ideal anesthetic agent for cardiac EP study and catheter ablation of SVT. The primary objective was to compare the effects of anesthetic agents on cardiac electrophysiological parameters and arrhythmia inducibility. The secondary objective was to compare the patient, anesthesiologist, and cardiologist satisfaction scores with respect to the anesthetic agent used. Materials and Methods: Thirty adult patients with SVT for EP study and radiofrequency catheter ablation were administered either of the anesthetic agents: midazolam, fentanyl, propofol, ketamine, or sevoflurane titrated to produce conscious sedation corresponding to bispectral index (BIS) values between 71 and 90. Electrophysiological parameters were recorded before and after administering the anesthetic agent. Results: Arrhythmia could be induced in all patients. Although electrophysiological parameters remained stable with ketamine administration; higher values of the Richmond Agitation Sedation Scale score and BIS were recorded. Propofol and sevoflurane administration was associated with deviation in electrophysiological parameters more than fentanyl and midazolam. The highest values of patient, anesthesiologist, and cardiologist satisfaction scores were obtained in the fentanyl group and the lowest in the ketamine group (P < 0.002). Conclusion: In doses used to provide conscious sedation, fentanyl provided ideal conditions, and midazolam, propofol, sevoflurane, and ketamine provided satisfactory conditions for conducting EP study and catheter ablation for supraventricular tachyarrhythmias. The potential of propofol to impede cardiac conduction needs to be explored further. [ABSTRACT FROM AUTHOR]

Objective: Ventricular extrasystole is one of the most common rhythm disorders in children, and almost all of them are characterized by normal cardiac functions without structural cardiac abnormalities. The aim of this study was to assess the clinical course of ventricular extrasystole in children who did not have cardiac structural abnormalities. Materials and Methods: This retrospective study analyzed 24-hour rhythm Holter recordings performed in our clinic in children. Patients diagnosed with isolated ventricular extrasystole in Holter records and without structural heart disease on echocardiography were included in the evaluation. Results: A total of 20 160 Holter results were evaluated in the study, and 226 patients (male; 66%) met the criteria. The mean follow-up time was 8.7 ± 3.2 years. While 81.8% of the patients were asymptomatic, the most common symptom was palpitation and 5 patients had syncope. Of the patients, 72 (31.8%) received medical therapy. Beta-blockers were the most often prescribed medication. Cardiomyopathy did not develop in any of the patients during the followup period. A partial reduction in the frequency of ventricular extrasystole was observed in 42% of the patients, while complete recovery was observed in 22%. Conclusion: Ventricular extrasystole in children generally has a good prognosis; most of them are asymptomatic, and the rates of spontaneous regression over time are quite high, regardless of the origin. [ABSTRACT FROM AUTHOR]

Background: Poor sleep quality is highly prevalent in atrial fibrillation (AF) with reported links between worse sleep quality and higher AF severity. Little research has examined whether sleep quality changes after AF ablation despite it being a routinely performed procedure. Objective: The aim of this study was to evaluate self-reported sleep quality before and after AF ablation and to examine whether sleep quality differs by AF severity or sex. Methods: This longitudinal pilot study assessed sleep using the Pittsburgh Sleep Quality Index at preablation and at 1, 3, and 6 months after ablation. Atrial fibrillation disease severity was assessed by the Canadian Cardiology Society Severity of AF scale. Outcomes were analyzed using descriptive statistics, Spearman ρ correlations, and multilevel longitudinal models. Results: The sample (N = 20) was 55% female with a mean age of 65 (±7) years. Poor sleep quality (mean Pittsburgh Sleep Quality Index scores > 5) was evident at all time points. Improvement was noted at 3 months (moderate effect size d = 0.49); and negligible further improvement, from 3 to 6 months post ablation. Improvement was seen primarily in male subjects (large effect size d = 0.89 at 3 months), with smaller improvements for female subjects. Although Severity of AF scale scores were not correlated with sleep quality, Severity of AF scale severity scores did significantly improve over time. Conclusions: Patients with AF have poor sleep quality that improves for the first 3 months after AF ablation, with men showing more improvement than women. A more accurate understanding of the sleep challenges after AF ablation could lead to development of more realistic patient education and improve patient self-management. [ABSTRACT FROM AUTHOR]

Introduction: Before ablation, predicting the site of origin (SOO) of outflow tract ventricular arrhythmia (OTVA), can inform patient consent and facilitate appropriate procedural planning. We set out to determine if OTVA variability can accurately predict SOO. Methods: Consecutive patients with a clear SOO identified at OTVA ablation had their prior 24‐h ambulatory ECGs retrospectively analysed (derivation cohort). Percentage ventricular ectopic (VE) burden, hourly VE values, episodes of trigeminy/bigeminy, and the variability in these parameters were evaluated for their ability to distinguish right from left‐sided SOO. Effective parameters were then prospectively tested on a validation cohort of consecutive patients undergoing their first OTVA ablation. Results: High VE variability (coefficient of variation ≥0.7) and the presence of any hour with <50 VE, were found to accurately predict RVOT SOO in a derivation cohort of 40 patients. In a validation cohort of 29 patients, the correct SOO was prospectively identified in 23/29 patients (79.3%) using CoV, and 26/29 patients (89.7%) using VE < 50. Including current ECG algorithms, VE < 50 had the highest Youden Index (78), the highest positive predictive value (95.0%) and the highest negative predictive value (77.8%). Conclusion: VE variability and the presence of a single hour where VE < 50 can be used to accurately predict SOO in patients with OTVA. Accuracy of these parameters compares favorably to existing ECG algorithms. [ABSTRACT FROM AUTHOR]

Background: In Italy, a nationwide full lockdown was declared between March and May 2020 to hinder the novel coronavirus disease 2019 (COVID‐19) pandemic. The potential individual health effects of long‐term isolation are largely unknown. The current study investigated the arrhythmic consequences of the COVID‐19 lockdown in patients with defibrillators (ICDs) living in the province of Ferrara, Italy. Methods: Both the arrhythmias and the delivered ICD therapies as notified by the devices were prospectively collected during the lockdown period (P1) and compared to those occurred during the 10 weeks before the lockdown began (P2) and during the same period in 2019 (P3). Changes in outcome over the three study periods were evaluated for significance using McNemar's test. Results: A total of 413 patients were included in the analysis. No differences were found concerning either arrhythmias or shocks or anti‐tachycardia pacing. Only the number of patients experiencing non‐sustained ventricular tachycardias (NSVTs) during P1 significantly decreased as compared to P2 (p = 0.026) and P3 (p = 0.009). The subgroup analysis showed a significant decrease in NSVTs during P1 for men (vs. P2, p = 0.014; vs. P3, p = 0.040) and younger patients (vs. P2, p = 0.002; vs. P3, p = 0.040) and for ischemic etiology (vs. P2, p = 0.003). No arrhythmic deaths occurred during P1. Conclusions: The complete nationwide lockdown, as declared by the Italian government during the first COVID‐19 pandemic peak, did not impact on the incidence of arrhythmias in an urban cohort of patients with ICDs. [ABSTRACT FROM AUTHOR]

Background: Patients with both true and false arrhythmia alarms pose a challenge because true alarms might be buried among a large number of false alarms, leading to missed true events. Objective: To determine (1) the frequency of patients with both true and false arrhythmia alarms; (2) patient, clinical, and electrocardiographic characteristics associated with both true and false alarms; and (3) the frequency and types of true and false arrhythmia alarms. Methods: This was a secondary analysis using data from an alarm study conducted at a tertiary academic medical center. Results: Of 461 intensive care unit patients, 211 (46%) had no arrhythmia alarms, 12 (3%) had only true alarms, 167 (36%) had only false alarms, and 71 (15%) had both true and false alarms. Ventricular pacemaker, altered mental status, mechanical ventilation, and cardiac intensive care unit admission were present more often in patients with both true and false alarms than among other patients (P <.001). Intensive care unit stays were longer in patients with only false alarms (mean [SD], 106 [162] hours) and those with both true and false alarms (mean [SD], 208 [333] hours) than in other patients. Accelerated ventricular rhythm was the most common alarm type (37%). Conclusions: An awareness of factors associated with arrhythmia alarms might aid in developing solutions to decrease alarm fatigue. To improve detection of true alarms, further research is needed to build and test electrocardiographic algorithms that adjust for clinical and electrocardiographic characteristics associated with false alarms. [ABSTRACT FROM AUTHOR]

The purpose of this study was to monitor heart rate (HR) and rhythm during open water SCUBA dives. Nine children performed 25-min open water SCUBA dives to 8 m depth. Before, during and after these dives, ECG was recorded. Comparedwith predive heart rate, heart rate declined by -24 ± 8% (range -36%; -15%) during the dive. In some children a further decline in HR was observed within the last minutes of the dive. Older and taller subjects and those with a high initial HR showed a more pronounced decline in HR. Furthermore singular supraventricular and ventricular extrasystoles were observed in some children. Immersion as well as facial and skin cooling presumably account for the initial decline in heart rate. A further drop in HR within the last minutes of the dive might be related to mild hypothermia. Single supraventricular and ventricular extrasystoles might occur in healthy children during dives. [ABSTRACT FROM AUTHOR]

Statistical analysis of count data typically starts with a Poisson regression. However, in many real-life applications, it is observed that the variation in the counts is larger than the mean, and one needs to deal with the problem of overdispersion in the counts. Several factors may contribute to overdispersion: (1) unobserved heterogeneity due to missing covariates, (2) correlation between observations (such as in longitudinal studies), and (3) the occurrence of many zeros (more than expected from the Poisson distribution). In this paper, we discuss a model that allows one to explicitly take each of these factors into consideration. The aim of this paper is twofold: (1) investigate whether we can identify the cause of overdispersion via model selection, and (2) investigate the impact of a misspecification of the model on the power of a covariate. The paper is motivated by a study of the occurrence of drug-induced arrhythmia in beagle dogs based on electrocardiogram recordings, with the objective to evaluate the effect of potential drugs on the heartbeat irregularities. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Background Variations in syncope management exist. Our objective was to identify the reasons for consultations and hospitalizations and outcomes among emergency department ( ED) syncope patients. Methods We conducted a prospective cohort study to enroll adult syncope patients at five EDs. We collected baseline characteristics, reasons for consultation and hospitalization, and hospital length of stay. Adjudicated 30-day serious adverse events ( SAEs) including death, myocardial infarction, arrhythmia, structural heart disease, pulmonary embolism, significant hemorrhage, and procedural intervention. We used descriptive analysis. Results From 4,064 enrolled patients (mean ± SD age = 53.1 ± 23.2 years; 55.9% female), 3,255 (80.1%) were discharged directly by the ED physician. Of those with no SAEs identified in the ED ( n = 600), 42.8% of referrals and 46.5% of hospitalizations were for suspected arrhythmias, and 71.2% of patients hospitalized for arrhythmias had no cause identified. SAEs among groups were 9.7% in total, 2.5% discharged by ED physician, 3.4% discharged by consultant, 21.7% as inpatient, and 4.8% following discharge from hospital. The median hospital length of stay for suspected arrhythmias was 5 days (interquartile range = 3 to 8 days). Conclusion Cardiac syncope, particularly suspected arrhythmia, was the major reason for ED referrals and hospitalization. The majority of patients hospitalized for cardiac monitoring had no identified cause. An important number of patients suffered SAEs, particularly arrhythmias, outside the hospital. Development of a risk-stratification tool and out-of-hospital cardiac monitoring strategy should improve patient safety and save substantial resources. [ABSTRACT FROM AUTHOR]

Clinical Trial Registration URL: . Unique Identifier: NCT00697359. Objectives To evaluate rhythm control up to two years after atrial fibrillation (AF) ablation and its relation to reported symptoms. Background The implantable loop recorder (ILR) continuously records the electrocardiogram (ECG), has an automatic AF detection algorithm, and has a possibility for patients to activate an ECG recording during symptoms. Methods Fifty-seven patients (mean age 57 ± 9 years, 60% male, 88% paroxysmal AF) underwent AF ablation following ILR implantation. Device data were downloaded at the ablation and three, six, 12, 18, and 24 months after ablation. Results Fifty-four patients completed the two-year follow-up. Thirteen (24%) patients had no AF episodes detected by ILR during follow-up. Ten of 41 patients (24%) with AF recurrence were only detected by ILR and AF recurrences were detected earlier by ILR (P < 0.001). The median AF burden in patients with AF recurrence was 5.7% (interquartile range 0.4-14.4) and was even lower in patients with AF only detected by ILR (P = 0.001). Forty-eight % of the patients indicated symptoms via the patient activator but 33% of those recordings were not due to AF. Early AF recurrence (within 3 months) was highly associated with later AF recurrence (P < 0.001). AF burden >0.5% and longest AF episode >6 hours before the ablation were independent predictors of AF recurrence during intermittent but not continuous monitoring. Conclusions After AF ablation, the AF burden was low throughout the 24 months follow-up. Nevertheless, symptoms were commonly indicated but one-third of patient-activated recordings did not show AF. Continuous monitoring was superior to intermittent follow-up in detecting AF episodes and assessing the AF burden. [ABSTRACT FROM AUTHOR]

Conserved Rotors in Recurrent AF Introduction Recurrent atrial fibrillation (AF) after ablation is associated with reconnection of initially isolated pulmonary vein (PV) trigger sites. Substrates are often targeted in addition to PVI, but it is unclear how substrates progress over time. We studied if substrates in recurrent AF are conserved or have developed de novo from pre-ablation AF. Methods and Results Of 137 patients undergoing Focal Impulse and Rotor Mapping (FIRM) at their index procedure for AF, 29 consecutive patients (60 ± 8 years, 79% persistent) recurred and were also mapped at repeat procedure (21 ± 20 months later) using carefully placed 64-pole baskets and RhythmViewTM (Topera, Menlo Park, CA, USA) to identify AF sources and disorganized zones. Compared to index AF, recurrent AF had a longer cycle length (177 ± 21 vs. 167 ± 19 milliseconds, P = 0.01). All patients (100%) had 1 or more conserved AF rotors between procedures with surrounding disorganization. The number of sources was similar for recurrent AF post-PVI versus index AF (3.2 ± 1.4 vs. 3.1 ± 1.0, P = 0.79), but was lower for recurrent AF after FIRM+PVI versus index AF (4.4 ± 1.4 vs. 2.9 ± 1.7, P = 0.03). Overall, 81% (61/75) of AF sources lay in conserved regions, while 19% (14/75) were detected de novo. Conclusion Electrical propagation patterns for recurrent AF after unsuccessful ablation are similar in individual patients to their index AF. These data support temporospatial stability of AF substrates over 1-2 years. Trials should determine the relative benefit of adding substrate mapping and ablation to PVI for recurrent AF. [ABSTRACT FROM AUTHOR]

Background: The aim of this study was to examine the effects of atomoxetine on heart rhythm using 12-lead electrocardiography (ECG) and 24 h Holter monitoring. Methods: Children and adolescents who were diagnosed with attention deficit-hyperactivity disorder according to DSM-IV-TR were referred to a pediatric cardiology clinic for cardiologic examination before and after 4 or 5 weeks of atomoxetine treatment. Cardiac examination, complete blood count, biochemistry, thyroid function tests, 12-lead ECG and 24 h Holter monitoring were performed routinely in all patients. Each subject underwent 24 h Holter ECG monitoring before atomoxetine was started and after 4 or 5 weeks of effective dose atomoxetine treatment. Results: Forty-one patients were included in this prospective study. No statistically significant change was found in QT, QTc or QT interval dispersion or blood pressure before and after 4 or 5 weeks of atomoxetine treatment. There was a statistically significant increase in heart rate (both during the day and at night) and QRS duration, and a statistically significant decrease in P wave dispersion. Three patients had rhythm disturbances. All of these three patients were asymptomatic and none of these arrhythmias reached clinical significance. Conclusion: Atomoxetine did not cause significant changes in ECG or Holter variables. In two patients, who had undiagnosed subclinical extrasystoles, extra beats were increased after 4th week of treatment, but still remained clinically insignificant. Before and after atomoxetine treatment, listening to the heart sounds for a longer time, may help clinicians to notice an extra beat. If an extra beat is identified then 24 Holter monitoring is recommended. [ABSTRACT FROM AUTHOR]

Introduction: Serum uric acid (SUA) may contribute to the increased cardiovascular damage through direct injury to the endothelium and alteration of cardiovascular function. Aim: To evaluate the association of SUA with the presence of the most recurrent electrographic alterations and with the length of the main ECG intervals in a large sample of general population. Methods: For this study, on the database of the Brisighella Heart Study, we evaluated the available data of 790 men and 849 women, excluding subjects affected by gout or taking antihyperuricemic agents, those taking drug increasing the QT interval and those using beta-blockers or non-dihydropyridine calcium channel blockers at the moment of the ECG registration. Multiple ascending stepwise regression analyses were carried out to determine the independent predictors of the predefined ECG alterations. Results: The prevalence of predefined ECG alterations was comparable between genders, with the exception of sinus bradicardia, left-anterior fascicular block, atrio-ventricular blocks and left ventricular hypertrophy (LVH), which appeared to be more frequent in men. The multivariate analysis revealed that SUA was associated to ischaemic alterations, LVH, sinus tachycardia and tachyarrhytmias. Age was associated to all evaluated ECG alterations beyond sinus tachycardia and LVH. Male sex was associated to sinus bradicardia, atrio-ventricular blocks, anterior-left fascicular block and LVH. Blood pressure was associated to different ECG alterations, but with clinically relevant OR with ischaemic alterations and LVH. Conclusion: SUA level is related the prevalence of both organic and rhythm ECG alterations in a wide sample of general population. [ABSTRACT FROM AUTHOR]

Background Epicardial adipose tissue (EAT) is a local source of various hormones, cytokines, and vasoactive substances affecting the myocardium. EAT contains abundant ganglionic plexi that interact with the autonomic nervous system. Evidence of the association between EAT and arrhythmia is limited, with the exception of atrial fibrillation. This study aimed to investigate the relation between EAT and cardiac autonomic function using heart rate variability (HRV) and heart rate turbulence (HRT) parameters. Methods All subjects underwent a 24-hour Holter recording to assess HRV and HRT parameters and a transthoracic echocardiography to measure EAT thickness. Patients were divided into two groups according to the median EAT thickness (3.9 mm). The higher EAT group consisted of 111 patients with a >3.9-mm thickness and the lower EAT group 113 patients with a ≤3.9-mm EAT thickness. Results HRV and HRT parameters were significantly influenced in the higher EAT group. Moreover, we observed significant correlations between EAT thickness and Holter findings (standard deviation of all NN intervals [SDNN]: r = -0.462, P < 0.001; SDNN index: r = -0.349, P < 0.001; standard deviation of the average NN intervals: r = -0.465, P < 0.001; root mean square of successive differences: r = -0.251, P < 0.001; pNN50: r = -0.354, P < 0.001; turbulence onset: r = 0.172, P = 0.010; turbulence slope: r = -0.279, P < 0.001, HRT category: r = 0.169, P = 0.011). In multivariate regression analysis, EAT thickness was independently associated with all measures of HRV and HRT, with the exception of turbulence onset. Conclusions Sympathovagal imbalance, detected by HRV and HRT parameters, is related to EAT thickness. As sympathovagal imbalance is a predictor of arrhythmic events, EAT may play an important arrhythmogenic role not limited to atrial fibrillation. [ABSTRACT FROM AUTHOR]

Bac kground: Few studies evaluated left ventricular (LV) involvement in arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C). The aim of this study is to determine the frequency, clinical presentation, and pattern of LV involvement in ARVD/C (LV-ARVD/C). Methods: We retrospectively evaluated the cardiac magnetic resonance (CMR) in 202 patients referred between 2008 and 2012 to our institution, and we determined the presence or the absence of CMR criteria in the revised task force criteria 2010 for the diagnosis of ARVD/C. A total of 21 patients were diagnosed with ARVD/C according to the revised task force criteria 2010. All included patients had no previous history of myocarditis, acute coronary syndrome, or any other cardiac disease that could interfere with the interpretations of structural abnormalities. The LV involvement in ARVD/C was defined by the presence of one or more of the following criteria: LV end-diastolic volume (LVEDV; .95 mL/m2), LV ejection fraction (LVEF; ,55%), LV late enhancement of gadolinium (LVLE) in a non-ischemic pattern, and LV wall motion abnormalities (WMAs). In the follow-up for the occurrence of cardiac death, ventricular tachycardia (VT) was obtained at a mean of 31 20.6 months. Results : A total of 21 patients had ARVD/C. The median age was 48 (33-63) years. In all, 11 patients (52.4%) had LV-ARVD/C. The demographic characteristics of patients with or without LV were similar. There was a higher frequency of left bundle-branch block (LBBB) VT morphology in ARVD/C (P 0.04). In CMR, regional WMAs of right ventricle (RV) and RV ejection fraction (RVEF; ,45%) were strongly correlated with LV-WMAs (r 0.72, P 0.02, r 0.75, P 0.02, respectively). RV late enhancement of gadolinium (RVLE) was associated with LV-WMs and LVLE (r 0.7, P 0.03; r 0.8, P 0.006). LVLE was associated with LV-WMAs, LVEF, and LVEDV (r 0.9, P 0.001; r 0.8, P 0.001; r 0.8, P 0.01). Conclusion: LV involvement in ARVD/C is common and frequently associated with moderate to severe right ventricular (RV) abnormalities. The impact of LV involvement in ARVD/C on the prognosis needs further investigations. [ABSTRACT FROM AUTHOR]

Predictors of LV Dysfunction with Idiopathic PVC Introduction Patients with frequent premature ventricular complexes (PVCs) might be at risk for the developing or exacerbation of left ventricular (LV) dysfunction. However, some patients with a high-PVC burden do not develop cardiomyopathy, while other patients with low-PVC burden can develop cardiomyopathy. The purpose of this study was to evaluate the positive predictors of idiopathic PVCs-induced cardiomyopathy. Methods and Results We investigated 214 patients undergoing successful ablation of PVCs who had no other causes of cardiomyopathy. We divided the study cohort into 2 groups: ejection fraction (EF) ≥ 50% (normal LV) and EF < 50% (LV dysfunction). We analyzed the clinical characteristics, including the electrocardiogram and findings at electrophysiology study. Among these patients, 51 (24%) had reduced LVEF and 163 (76%) had normal LV function. Patients with LV dysfunction had significantly longer coupling interval (CI) dispersion (maximum-CI-minimum-CI) and had significantly higher PVC burden compared to those with normal LV function (CI-dispersion: 115 ± 25 milliseconds vs. 94 ± 19 milliseconds; P < 0.001; PVC burden: 19% vs. 15%; P = 0.04). Furthermore, patients with LV dysfunction had significantly higher body mass index (BMI) compared to those with normal LV function (BMI > 30 kg/m2; 37% vs. 13%; P = 0.001). Logistic regression analysis showed that CI-dispersion, PVC burden, and BMI (>30 kg/m2) are independent predictors of PVC-induced cardiomyopathy. Conclusions In addition to the PVC burden, the CI-dispersion and BMI are associated with PVC-induced cardiomyopathy. [ABSTRACT FROM AUTHOR]

Objective. RA associates with an increased rate of sudden cardiac death (SCD). A prolonged QTc interval has been associated with arrhythmogenic and SCD in patients with long QT syndrome. Despite the previously reported contemporary association of CRP with SCD, thus far no studies have examined the association of QTc with mortality in RA, a condition characterized by high inflammatory burden. The aim of this study was to examine the role of electrocardiography (QT corrected interval) in predicting all-cause mortality in patients with RA who have an increased rate of SCD and a high inflammatory burden.Methods. Three hundred and fifty-seven RA patients with detailed baseline clinical characterization and 12-lead ECGs were followed up for a mean of 73.0 (s.d. 18.3) months. Linear and Cox regression analyses were used to identify variables that associate with QTc and examine its association with all-cause mortality.Results. The patients’ mean age was 60.6 (s.d. 12.0) years, 267 (74.8%) were females and 54 (15.1%) died during the follow-up period. Age (β = 0.231, P < 0.001), gender (β = 0.137, P = 0.008) and CRP (β = 0.144, P = 0.006) associated independently with QTc in RA patients. The crude hazard ratio (HR) for total mortality per 50-ms increase in QTc was 2.17 (95% CI 1.21, 3.90). This association remained significant [HR = 2.18 (95% CI 1.09, 4.35)] after adjustment for identified confounders (cardiovascular and RA specific), but was lost [HR = 1.73 (95% CI 0.83, 3.62)] when CRP was included in the model.Conclusion. A 50-ms increase in QTc interval associates with a doubling of the hazard for all-cause mortality in patients with RA. The observed contemporary association of QTc with CRP levels indicates a potentially hazardous interplay between inflammation and arrhythmogenesis. Future studies are needed to confirm the above findings and explore underlying mechanisms. [ABSTRACT FROM PUBLISHER]

Aims and objectives To determine the relationship between quality of life and perceived self-reported symptoms in an older, ambulatory, urban population living with heart failure. Background While arrhythmias in older individuals with heart failure are well documented, the association between perceived arrhythmia symptoms and quality of life is not well-defined. Design Prospective, cross-sectional single-centre study. Methods A single-centre, prospective study was conducted with heart failure patients recruited from an urban outpatient cardiology clinic in the United States. Fifty-seven patients completed a baseline quality of life survey with 42 of these completing the six-month follow-up survey. Quality of life was evaluated with the SF-36v2™ and frequency of symptoms with the Atrial Fibrillation Severity Scale. Subjects wore an auto triggered cardiac loop monitor (LifeStar AF Express®) for two weeks to document arrhythmias. Data analysis utilised Spearman's rank correlation and logistic regression. Results Baseline and six-month quality of life measures did not correlate with recorded arrhythmias. However, perceptions of diminished general health correlated significantly with symptoms of exercise intolerance, lightheadedness/dizziness, palpitations and chest pain/pressure. By multivariable logistic regression, more severe perceived episodes, symptoms of exercise intolerance and lightheadedness/dizziness were independently associated with diminished quality of life. Conclusion Quality of life was significantly worse in patients with perceptions of severe arrhythmic episodes and in those with symptoms of dizziness and exercise intolerance. Relevance to clinical practice The findings of this study indicate that symptomatic heart failure patients suffer from poor quality of life and that interventions are needed to improve quality of life and decrease symptom severity. Nurses who care for heart failure patients play an essential role in symptom evaluation and management and could significantly improve overall quality of life in these patients by carefully evaluating symptomatology and testing interventions and educational programmes aimed at improving quality of life. [ABSTRACT FROM AUTHOR]

Sudden Cardiac Death. Introduction: Sudden cardiac death (SCD) is a large public health problem that warrants on-going evaluation in the general population. While single-year community-based studies have been performed there is a lack of studies that have extended evaluation to multiple years in the same community. Methods and Results: From the on-going Oregon Sudden Unexpected Death Study, we analyzed prospectively identified SCD cases in Multnomah County, Ore, (population ≈700,000) from February 1, 2002 to January 31, 2005. Detailed information ascertained from multiple sources (first responders, clinical records, and medical examiner) was analyzed. A total of 1,175 SCD cases were identified (61% male) with a mean age of 65 ± 18 years for men versus 70 ± 20 for women (P < 0.001). The overall incidence rate for the period was 58/100,000 residents/year. One-quarter (24.6%) was ≤55 years of age. The most common initial rhythm was ventricular tachycardia or fibrillation (39% of cases, survival 27%) followed by asystole (36%, survival 0.7%) and pulseless electrical activity (23%, survival 6%). Among subjects that underwent resuscitation, the rate of survival to hospital discharge was 12% and overall survival to hospital discharge irrespective of resuscitation was 8%. Of the 68 survivors, 16 (24%) received a secondary prevention ICD. Conclusion: We report annualized SCD incidence from a multiple-year, multiple-source community-based study, with higher than expected rates of women and subjects age ≤55 years. The low implantation rate of secondary prevention ICDs is likely to be multifactorial, but there are potential implications for recalibration of the projected need for ICD implantation; larger and more detailed studies are warranted. (J Cardiovasc Electrophysiol, Vol. 24, pp. 60-65, January 2013) [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate HRV in children requiring intensive care unit stays due to TCA poisoning between March 2009 and July 2010. In the time-domain nonspectral evaluation, the SDNN(P < 0.001), SDNNi (P < 0.05), RMSDD(P < 0.01), and pNN50 (P < 0.01) were found to be significantly lower in the TCA intoxication group. The spectral analysis of the data recorded during the first 5 minutes after intensive care unit admission showed that the values of the nLF (P < 0.05) and the LF/HF ratio (P = 0.001) were significantly higher in the TCA intoxication group, while the nHF (P = 0.001) values were significantly lower. The frequency-domain spectral analysis of the data recorded during the last 5 minutes showed a lower nHF (P = 0.001) in the TCA intoxication group than in the controls, and the LF/HF ratio was significantly higher (P < 0.05) in the intoxication group. The LF/HF ratio was higher in the seven children with seizures (P < 0.001). These findings provided us with a starting point for the value of HRV analysis in determining the risk of arrhythmia and convulsion in TCA poisoning patients. HRV can be used as a noninvasive testing method in determining the treatment and prognosis of TCA poisoning patients. [ABSTRACT FROM AUTHOR]

Objective To assess the frequency of rhythm disturbances (RDs) obtained following placement of a Holter monitor or an event loop recorder (ERT) in patients referred to cardiologists. Study Design Ninety-six gravidas were referred to the cardiology clinic for palpitations, syncope, or dizziness and had Holter monitoring or ERT after a baseline electroencephalogram. Arrhythmias were classified by severity. Results Gestational age at referral was 22.6 weeks ± 8.3 days. Sixty-five patients had ERTs performed, and 19 had Holter monitors. Seventy-six percent had benign arrhythmias. In our ERT cohort, history of arrhythmias showed a fourfold increase in serious RD during gestation (odds ratio [OR] 4.7, 95% confidence interval [CI] 1.1 to 20.3, p = 0.01); obesity (body mass index >30) had a fourfold increased risk (OR 4.0, 95% CI 1.0 to 1, p = 0.03). Serious RD did not result in greater chance of cesarean delivery or induction of labor, or a newborn with arrhythmias. Conclusion Most pregnant women with palpitations have benign arrhythmias. ERT appears to be a better method of diagnosis in pregnant women. [ABSTRACT FROM AUTHOR]

Objective: Eating disorders, in particular anorexia nervosa (AN), are associated with cardiovascular complications and risk of arrhythmias. In a recent published study, it was found that patients with eating disorders, especially those affected by bulimia nervosa (BN) and a history of AN have abnormal late ventricular potentials (LPs). LPs are electrocardiographic markers used in detecting abnormal depolarization and increased risk of arrhythmias. Given the paucity of knowledge regarding the affects of eating disorders on cardiac depolarization, our aim was to further explore LPs in patients with eating disorders. Method: The study group included 30 hospitalized patients with eating disorders (14 with AN, 10 with BN with no history of AN, and 6 with BN and history of AN). Signal averaged electrocardiography was conducted on all patients usingthe Frank corrected orthogonal lead system. Results: No patient with either eating disorder tested positive for LPs. Discussion: Hospitalized patients with eating disorders, medically monitored and treated for several weeks, had normal serum electrolytes, started to normalize their weight, and did not appear to be prone to arrhythmias associated with abnormal depolarization. The prognostic significance of LPs in risk stratification of patients with eating disorders should be further evaluated by large cohort studies and longer follow-up studies. © 2011 by Wiley Periodicals, Inc. (Int J Eat Disord 2011;45:900-904) [ABSTRACT FROM AUTHOR]

The article reports on research which was conducted to investigate the impact that extreme exercise had on cardiac repolarization and other electrophysiological factors. Researchers evaluated the electrocardiograms of 198 healthy men who participated in a marathon. They found that cardiac repolarization was significantly altered immediately after a marathon, coincident with hypomagnesemia and hypokalemia, and that runners' inflammatory and electrolyte statuses returned to baseline values within 72 hours of running the marathon.

Patients with heart failure (HF) are at increased risk for drug-induced torsades de pointes (TdP) due to unknown mechanisms. Our objective was to determine if sensitivity to drug-induced QT interval lengthening is enhanced in patients with HF. In this multicenter, prospective study, 15 patients with atrial fibrillation or flutter requiring conversion to sinus rhythm were enrolled: 6 patients with New York Heart Association class II to III HF (mean ejection fraction [EF], 30% ± 9%), and 9 controls (mean EF, 53% ± 6%). Patients received ibutilide 1 mg intravenously. Blood samples and 12-lead electrocardiograms were obtained prior to and during 48 hours postinfusion. Serum ibutilide concentrations at 50% maximum effect on Fridericia-corrected QT (QTF) intervals (EC50) were determined, and areas under the effect (QTF interval vs time) curves (AUECs) were calculated. Ibutilide concentration–QTF relationships were best described by a sigmoidal Emax model with a hypothetical effect compartment. Median [interquartile range] AUEC from 0 to 4 hours was larger in the HF group than in controls (1.86 [1.86-1.93] vs 1.82 [1.81-1.84] s·h; P = .04). Median EC50 was lower in the HF group (0.48 [0.46-0.49] vs 1.85 [1.10-3.23] μg/L; P = .008). Sensitivity to drug-induced QT interval lengthening is enhanced in patients with systolic HF, which may contribute to the increased risk of drug-induced TdP. [ABSTRACT FROM PUBLISHER]

Aim: To determine the frequency of occurrence, risk factors, clinical spectrum and drugs associated with adverse drug reactions (ADRs) occurring in the coronary care unit (CCU) of a tertiary care hospital. Methods: This was a retrospective cohort study based on evaluation of the medical records of consecutive patients admitted to the CCU between January 2008 and December 2008. Each prescription was monitored for ADRs, and each ADR was assessed for causality, severity, predictability and preventability by two physicians using relevant scales. The chi-square test and independent t test were used to compare the ADR and non-ADR groups. Multiple binary logistic regression was used to identify risk factors for developing ADRs in the CCU. Results: Of 595 patients, 152 (25.5%) developed ADRs, of which 45% were potentially preventable. Severe ADRs constituted 28.6% of the total ADRs. Patients who developed an ADR had a longer duration of stay in the hospital (2.8 extra days) ( p < 0.05). Hypokalemia/hyperkalemia (22%), bleeding (11%) and cardiac arrhythmias (11%) were the commonest ADRs. The highest rates of ADRs were seen with streptokinase (59.4%). The predictors for developing an ADR in the CCU included renal dysfunction [odds ratio (OR) 1.66, 95% confidence interval (CI) 1.007-2.72], arrhythmias (OR 1.74, 95% CI 1.052-2.87) and polypharmacy with more than ten drugs (OR 11.3, 95% CI 1.45-87.44). Conclusion: A high frequency of ADR occurrence was identified, with many of the ADRs being potentially preventable. Patients with renal dysfunction or cardiac arrhythmias and those receiving polypharmacy were at an increased risk for developing an ADR in the CCU. [ABSTRACT FROM AUTHOR]

Objective: To determine the prevalence and the prognostic value of exercise-induced ventricular arrhythmia (EIVA) in chronic Chagas' heart disease. Study Design and Setting: An open prospective cohort of 130 clinically stable patients at a University Hospital outpatient unit in Rio de Janeiro, Brazil, was followed up at scheduled clinical visits from 1990 through 2007. The endpoint was total cardiovascular mortality. Survival curves (Kaplan-Meier) and a multivariate Cox proportional hazard model were adjusted to determine the association between EIVA and mortality. Results: The median duration of follow-up was 9.9 years (range, 132 days to 17 years). EIVA prevalence was 43.1% (95% CI: 34.5-51.7). Thirty-three cardiovascular deaths (25.4%) occurred. The hazard ratio of EIVA for cardiovascular death, after adjustment for age, was 1.84 (P = 0.09). An interaction was found between EIVA and cardiomegaly on x-ray. In the group with cardiomegaly, the hazard of dying was four times greater in the presence of EIVA (P for interaction = 0.05). Conclusion: In clinically stable chagasic subjects with cardiomegaly, EIVA is a clinically significant marker of total cardiovascular mortality and may be a useful risk stratification tool in this population. (PACE 2011; 34:1492-1497) [ABSTRACT FROM AUTHOR]

. (J Cardiovasc Electrophysiol, Vol. 22, pp. 669-676, June 2011) [ABSTRACT FROM AUTHOR]

OBJECTIVE: The objective of this study was to compare the rate of severe cardiovascular events and death in children who use attention-deficit/hyperactivity disorder (ADHD) medications versus nonusers. PATIENTS AND METHODS: We performed a large cohort study using data from 2 administrative databases. All children aged 3 to 17 years with a prescription for an amphetamine, atomoxetine, or methylphenidate were included and matched with up to 4 nonusers on the basis of data source, gender, state, and age. Cardiovascular events were validated using medical records. Proportional hazards regression was used to calculated hazard ratios. RESULTS: We identified 241 417 incident users (primary cohort). No statistically significant difference between incident users and nonusers was observed in the rate of validated sudden death or ventricular arrhythmia (hazard ratio: 1.60 [95% confidence interval (CD: 0.19-13.60]) or all-cause death (hazard ratio: 0.76 [95% CI: 0.52-1.12]). None of the strokes identified during exposed time to ADHD medications were validated. No myocardial infarctions were identified in ADHD medication users. No statistically significant difference between prevalent users and nonusers (secondary cohort) was observed (hazard ratios for validated sudden death or ventricular arrhythmia: 1.43 [95% CI: 0.31-6.61]; stroke: 0.89 [95% CI: 0.11-7.11]; stroke/myocardial infarction: 0.72 [95% CI: 0.09-5.57]; and all-cause death: 0.77 [95% CI: 0.56- 1.07). CONCLUSIONS: The rate of cardiovascular events in exposed children was very low and in general no higher than that in unexposed control subjects. Because of the low number of events, we have limited ability to rule out relative increases in rate. [ABSTRACT FROM AUTHOR]

The article presents a study regarding the measurement of employer-sponsored postablation costs for cardiac arrhythmias (CA) specifically atrial fibrillation (AF) in the U.S. Health System. The method conducted in the study was the relative pre/postindex comparison between ablation and nonablation cohorts were calculated. It concludes that the ablation use in employer-sponsored health plans may improved health care and absence costs over time.

Most clinical studies of the clinical profile of Brugada syndrome (BS) have been conducted in either Asia, Europe, or America and their applicability to North African populations is largely unknown. The aim of the study was to analyze the clinical profile of BS in Tunisian patients. The clinical and follow-up data of 24 patients (22 men, mean age: 40.8 ± 13.7 years) were collected since 2002. Baseline characteristics, morbidity, and mortality data were obtained from medical records. One patient (4.16%) survived sudden cardiac death (SCD), four patients (16.3%) had syncope, and 19 patients (79.1%) were asymptomatic. Eleven patients (45.8%) had a family history of SCD. Twenty patients showed a spontaneous coved-type ST-segment elevation on electrocardiogram and after medical challenge on the four remnants. An electrophysiological study was performed in 15 of 24 patients (62.5%), during which ventricular fibrillation was induced in six patients (40%); three of the six patients were previously asymptomatic. An implantable cardioverter defibrillator (ICD) was implanted in 14 patients (58.3%). After a mean follow-up of 26 ± 21 months, one patient died from a noncardiac cause and one patient (with a history of aborted SCD) received an appropriate shock from his ICD. None of the asymptomatic and noninducible patients experienced a cardiac event. BS is present in the North African population and is probably under-recognized. Tunisian patients with BS share with their western and Asiatic counterparts similar clinical profile. (PACE 2011; 47-53) [ABSTRACT FROM AUTHOR]

Whether acute and direct percutaneous transluminal coronary angioplasty improves the incidence of nonsustained ventricular tachycardia in patients surviving acute myocardial infarction is not known. In 400 consecutively studied patients, Lown classification IVb on Holter monitoring was only associated with arrhythmia morbidity, whereas reduced ejection fraction was related to total and cardiac mortality and arrhythmia morbidity. [ABSTRACT FROM AUTHOR]

Background Potential interference between implanted cardiac devices and other medical instruments is an important concern. Therefore, we aimed to investigate the possible device interaction between implantable cardioverter defibrillators (ICDs) and external enhanced counterpulsation (EECP) treatment. Methods Twenty-one patients with an implanted ICD or cardiac resynchronization therapy with defibrillator (CRT-D) were enrolled into the study. EECP had applied as two sessions of 5 minutes. Data from device interrogations before and after the first EECP session and during second EECP session were recorded and analyzed for signs of possible device interaction. Results There was no sign of inappropriate sensing or noise during EECP session. There was no difference regarding electrode impedance, pacing, and sensing values before and after EECP. There was a statistically significant difference regarding heart rates during EECP therapy between rate response off and on modes (68.69 ± 5.92 beats/min and 90.32 ± 11.05 beats/min, respectively P = 0,001). In four patients with CRT-D and unipolar left ventricular pacing, counterpulsation could not be done because of QRS sensing problems. Conclusions EECP seems to be a safe treatment modality in patients with implanted ICD and CRT-D devices. It should be kept in mind that in those patients with CRT-D, rate responsive mode is on; inappropriate sinus tachycardia can be seen during EECP therapy. Also in patients with CRT-D using a unipolar sensing mode, problems of QRS complex sensing by the EECP may occur and, therefore, this effects synchronization and success of EECP therapy. [ABSTRACT FROM AUTHOR]

Question Is oral fluoroquinolone treatment associated with serious arrhythmia? Methods Design Matched cohort study with linkage of national prescription, patient, and death registries. Setting Denmark and Sweden. Patients 1 819 312 treatment courses in adults 40 to 79 years of age (mean age 61 y, 54% men) who had filled prescriptions for oral fluoroquinolones (n = 909 656) or penicillin V (n = 909 656) between 1997 to 2011 in Denmark and 2006 to 2013 in Sweden; patients could contribute = 1 treatment course. Exclusion criteria included hospital admission, antibiotic prescription filled within 45 days of the index prescription date, end-stage noncardiovascular (CV) disease, or substance misuse. Patients who received fluoroquinolones were matched with patients who received penicillin V using propensity scores based on country of residence, age, sex, country of birth, region of residence, calendar period, calendar year, medical history (cardiac, cerebrovascular, venous thromboembolism, renal, respiratory, or rheumatic disease), alcohol misuse, psychiatric conditions, hospital admissions, emergency department visits, CV disease-related visits, concomitant drugs, and prescriptions in the past year. Risk factors Current (0 to 7 d from index date), indeterminate (8 to 14 d), and past use (15 to 44 d) of oral fluoroquinolones or penicillin V. Outcome Serious arrhythmia (fatal and nonfatal). Main results Fluoroquinolones included ciprofloxacin (83%), norfloxacin (12%), ofloxacin (3%), moxifloxacin (1%), and other fluoroquinolones (1%). 144 incidences of arrhythmia occurred during the current use period; rates of arrhythmia did not differ for fluoroquinolones and penicillin V for any period of use (Table). Conclusion Oral fluoroquinolone treatment was not associated with serious arrhythmia compared with penicillin V. [ABSTRACT FROM AUTHOR]