Presence Of Sinus Rhythm Research Articles

Sex differences in long-term mortality among acute myocardial infarction patients: Results from the ISAR-RISK and ART studies.

BackgroundMortality rates in females who survived acute myocardial infarction (AMI) exceed those in males. Differences between sexes in age, cardiovascular risk factors and revascularization therapy have been proposed as possible reasons.ObjectiveTo select sets of female and male patients comparable in respect of relevant risk factors in order to compare the sex-specific risk in a systematic manner.MethodsData of the ISAR-RISK and ART studies were investigated. Patients were enrolled between 1996 and 2005 and suffered from AMI within 4 weeks prior to enrolment. Patients of each sex were selected with 1:1 equivalent age, previous AMI history, sinus-rhythm presence, hypertension, diabetes mellitus, smoking status, left ventricular ejection fraction (LVEF), and revascularization therapy. Survival times were compared between sex groups in the whole study cohort and in the matched cohort.ResultsOf 3840 consecutive AMI survivors, 994 (25.9%) were females and 2846 (74.1%) were males. Females were older and suffered more frequently from hypertension and diabetes mellitus. In the whole cohort, females showed an increased mortality with a hazard ratio (HR) of 1.54 compared to males (p<0.0001). The matched cohort comprised 802 patients of each sex and revealed a trend towards poorer survival in females (HR for female sex 1.14; p = 0.359). However, significant mortality differences with a higher risk in matched females was observed during the first year after AMI (HR = 1.61; p = 0.045) but not during the subsequent years.ConclusionMatched sub-groups of post-AMI patients showed a comparable long-term mortality. However, a female excess mortality remained during first year after AMI and cannot be explained by differences in age, cardiovascular risk factors, and modes of acute treatment. Other causal factors, including clinical as well as psychological and social aspects, need to be considered. Female post-AMI patients should be followed more actively particularly during the first year after AMI.

Predictors of Death in Contemporary Adult Patients With Eisenmenger Syndrome: A Multicenter Study.

Eisenmenger syndrome is associated with substantial morbidity and mortality. There is no consensus, however, on mortality risk stratification. We aimed to investigate survival and predictors of death in a large, contemporary cohort of Eisenmenger syndrome patients. In a multicenter approach, we identified adults with Eisenmenger syndrome under follow-up between 2000 and 2015. We examined survival and its association with clinical, electrocardiographic, echocardiographic, and laboratory parameters. We studied 1098 patients (median age, 34.4 years; range, 16.1-84.4 years; 65.1% female; 31.9% with Down syndrome). The majority had a posttricuspid defect (n=643, 58.6%), followed by patients with a complex (n=315, 28.7%) and pretricuspid lesion (n=140, 12.7%). Over a median follow-up of 3.1 years (interquartile range, 1.4-5.9), allowing for 4361.6 patient-years observation, 278 patients died and 6 underwent transplantation. Twelve parameters emerged as significant predictors of death on univariable analysis. On multivariable Cox regression analysis, only age (hazard ratio [HR], 1.41/10 years; 95% confidence interval [CI], 1.24-1.59; P<0.001), pretricuspid shunt (HR, 1.56; 95% CI, 1.02-2.39; P=0.041), oxygen saturation at rest (HR, 0.53/10%; 95% CI, 0.43-0.65; P<0.001), presence of sinus rhythm (HR, 0.53; 95% CI, 0.32-0.88; P=0.013), and presence of pericardial effusion (HR, 2.41; 95% CI, 1.59-3.66; P<0.001) remained significant predictors of death. There is significant premature mortality among contemporary adults with Eisenmenger syndrome. We report, herewith, a multivariable mortality risk stratification model based on 5 simple, noninvasive predictors of death in this population.

Large Left Atrial Appendage Thrombus in Sinus Rhythm Diagnosed with Transthoracic Echocardiogram

A 69-year-old gentleman with history of obstructive sleep apnoea, asthma, hypertension and chronic kidney disease presented with several-week history of symptoms consistent with NYHA class III heart failure. His ECG showed sinus rhythm with no ischaemic changes and blood tests showed Hs-TnT 32 ng/L, NT-proBNP 210 pmol/L and a normal coagulation screen. Transthoracic echocardiogram revealed a large mobile thrombus measuring 35 mm x 11 mm in the left atrial appendage (LAA) prolapsing into the left ventricle during diastole and a moderate size thrombus at the apex of the left ventricle. His left ventricular systolic function was moderately impaired with multiple regional wall abnormalities. Coronary angiogram showed severe triple vessel disease. Warfarin was commenced in addition to evidence based heart failure medications. Sinus rhythm was recorded throughout his inpatient stay. Repeat transthoracic echocardiography a week later showed complete resolution of the two thrombi. The plan for him was to complete a period of anticoagulation, continue anti-failure medications and to go forward for surgical revascularisation. LAA is the source of thrombus formation in up to 90% of cardioembolic stroke cases in non-valvular AF. In valvular AF, more than half of the thrombi are located in the atrial cavity rather than the LAA. Detecting a thrombus in the LAA in the presence of sinus rhythm is rare. To detect a thrombus in the LAA with transthoracic echocardiogram in a patient with sinus rhythm and only moderately impaired LV function to our knowledge hasn’t been reported in literature previously.

Acute cardioversion vs a wait-and-see approach for recent-onset symptomatic atrial fibrillation in the emergency department: Rationale and design of the randomized ACWAS trial

Current standard of care for patients with recent-onset atrial fibrillation (AF) in the emergency department aims at urgent restoration of sinus rhythm, although paroxysmal AF is a condition that resolves spontaneously within 24 hours in more than 70% of the cases. A wait-and-see approach with rate-control medication only and when needed cardioversion within 48 hours of onset of symptoms is hypothesized to be noninferior, safe, and cost-effective as compared with current standard of care and to lead to a higher quality of life. The ACWAS trial (NCT02248753) is an investigator-initiated, randomized, controlled, 2-arm noninferiority trial that compares a wait-and-see approach to the standard of care. Consenting adults with recent-onset symptomatic AF in the emergency department without urgent need for cardioversion are eligible for participation. A total of 437 patients will be randomized to either standard care (pharmacologic or electrical cardioversion) or the wait-and-see approach, consisting of symptom reduction through rate control medication until spontaneous conversion is achieved, with the possibility of cardioversion within 48 hours after onset of symptoms. Primary end point is the presence of sinus rhythm on 12-lead electrocardiogram at 4 weeks; main secondary outcomes are adverse events, total medical and societal costs, quality of life, and cost-effectiveness for 1 year. The ACWAS trial aims at providing evidence for the use of a wait-and-see approach for patients with recent-onset symptomatic AF in the emergency department.

A rare pathology on the anterior mitral valve leaflet

Cardiac myxomas are most common tumors encountered in the left atrium and the transesophageal echo (TEE) appearance of myxomas may mimic a thrombus. Left atrial thrombi are more common than myxomas especially in patients with ventricular dysfunction, atrial fibrillation, mitral valve disease and they are classically found in the left atrial appendage. The incidence of left atrial thrombi in the presence of sinus rhythm is detected in only 0.1 % patients, in more than 20,000 TEE exams conducted over an 11-year period. In this encounter, patient had multiple pedunculated thrombi arising from an isolated point source on the A2 segment of the mitral valve leaflet. There was no prior history of any organic heart disease. In addition, there was no evidence of stasis in the left atrium.

Preexcitation Syndromes

The classic electrocardiogram in Wolff-Parkinson-White (WPW) syndrome is characterized by a short PR interval and prolonged QRS duration in the presence of sinus rhythm with initial slurring. The clinical syndrome associated with above electrocardiogram finding and the history of paroxysmal supraventricular tachycardia is referred to as Wolff-Parkinson-White syndrome. Various eponyms describing accessory or anomalous conduction pathways in addition to the normal pathway are collectively referred to as preexcitation syndromes. The latter form and associated eponyms are frequently used in literature despite controversy and disagreements over their actual anatomical existence and electrophysiological significance. This communication highlights inherent deficiencies in the knowledge that has existed since the use of such eponyms began. With the advent of curative ablation, initially surgical, and then catheter based, the knowledge gaps have been mostly filled with better delineation of the anatomic and electrophysiological properties of anomalous atrioventricular pathways. It seems reasonable, therefore, to revisit the clinical and electrophysiologic role of preexcitation syndromes in current practice.

Approach to the Treatment of Atrial Fibrillation in Patients with Cardiovascular Risk Profile: Multicentric International Study

Atrial fibrillation (AF), the most common arrhythmia that requires treatment, does not come out of the focus of researchers. Monitoring its prevalence and effects of therapy is a good guideline approach to the growing population of patients in which this arrhythmia occurs. The aim of the study was to evaluate the efficacy of treatment of AF and cardiovascular profiles in the observed population. In this observational, cross-sectional, multicenter, international study, 584 patients in 30 centers in Serbia and Slovenia, older than 18 years and with AF or in sinus rhythm with a history of AF, were included. The assessment of the efficacy of treatment of AF was performed by analyzing the frequency of adequate therapeutic effect of medication in rhythm or frequency control in patients with AF. The results confirmed that the highest incidence of AF duration is more than seven days, and is accompanied by symptoms. Inadequate frequency regulation was registered at 8.9% of patients. Hypertension was registered in two-thirds of all patients, while other cardiovascular risk factors were registered in about one-third of patients. An echocardiographic finding in the group of patients with AF confirms generally adequate left ventricular function with a slightly enlarged left atrium (4.6±0.8 cm). Increasing age and time from the first episode of AF decreases the probability of maintaining sinus rhythm, while symptomatic AF had a positive impact on the presence of sinus rhythm. Propafenone, sotalol and amiodarone showed a statistically significant connection with a positive therapeutic response, while 3-blockers had a negative impact on the probability of establishing and maintaining sinus rhythm. Characteristics of therapeutic approaches, risks, comorbidity of patient populations in Slovenia and Serbia correspond to the fullest extent with the recommendations for good clinical practice, which further stresses the need for extensive measures in these regions.

Efficacy of β blockers in patients with heart failure plus atrial fibrillation: an individual-patient data meta-analysis

Atrial fibrillation and heart failure often coexist, causing substantial cardiovascular morbidity and mortality. β blockers are indicated in patients with symptomatic heart failure with reduced ejection fraction; however, the efficacy of these drugs in patients with concomitant atrial fibrillation is uncertain. We therefore meta-analysed individual-patient data to assess the efficacy of β blockers in patients with heart failure and sinus rhythm compared with atrial fibrillation. We extracted individual-patient data from ten randomised controlled trials of the comparison of β blockers versus placebo in heart failure. The presence of sinus rhythm or atrial fibrillation was ascertained from the baseline electrocardiograph. The primary outcome was all-cause mortality. Analysis was by intention to treat. Outcome data were meta-analysed with an adjusted Cox proportional hazards regression. The study is registered with Clinicaltrials.gov, number NCT0083244, and PROSPERO, number CRD42014010012. 18,254 patients were assessed, and of these 13,946 (76%) had sinus rhythm and 3066 (17%) had atrial fibrillation at baseline. Crude death rates over a mean follow-up of 1·5 years (SD 1·1) were 16% (2237 of 13,945) in patients with sinus rhythm and 21% (633 of 3064) in patients with atrial fibrillation. β-blocker therapy led to a significant reduction in all-cause mortality in patients with sinus rhythm (hazard ratio 0·73, 0·67-0·80; p<0·001), but not in patients with atrial fibrillation (0·97, 0·83-1·14; p=0·73), with a significant p value for interaction of baseline rhythm (p=0·002). The lack of efficacy for the primary outcome was noted in all subgroups of atrial fibrillation, including age, sex, left ventricular ejection fraction, New York Heart Association class, heart rate, and baseline medical therapy. Based on our findings, β blockers should not be used preferentially over other rate-control medications and not regarded as standard therapy to improve prognosis in patients with concomitant heart failure and atrial fibrillation. Menarini Farmaceutica Internazionale (administrative support grant).

A survey on the treatment of atrial fibrillation in South Africa.

The burden of cardiovascular disease is expected to escalate in developing countries. However, studies and guidelines concerning atrial fibrillation (AF) are restricted to the developed world. To assess the treatment modalities of AF in South Africa. A cross-sectional, observational, multicentre, national registry of the treatment of 302 patients with AF was conducted from February 2010 to March 2011. Specific drug use for rate or rhythm control, as well as drug use for stroke prevention, was surveyed. Events during the 12 months prior to the survey were also characterised, including non-drug treatments, resource utilisation and complications. The single most prevalent clinical characteristic was hypertension (65.9%). Rhythm control was being pursued in 109 patients (36.1%) with class Ic and class III antiarrhythmic agents, while rate control, mainly with beta-blockers, was pursued in the remainder of the patients. Concomitant use of other cardiovascular drugs was high, and 75.2% of patients were on warfarin for stroke prevention. There was a high burden of AF-related morbidity during the preceding year, with 32.5% reporting a history of heart failure, 8.3% a stroke and 5.3% a transient ischaemic attack. Therapeutic success, as defined by either the presence of sinus rhythm or rate-controlled AF, was achieved in 86.8% as judged clinically by the treating physician, but in only 70.2% according to the electrocardiogram criterion of heart rate ≤80 bpm. There were no striking differences from previously reported registries worldwide. The lack of application of strict rate control criteria is highlighted.

Prognostic Significance of ECG Abnormalities for Mortality Risk in Acute Heart Failure: Insight From the Sub-Saharan Africa Survey of Heart Failure (THESUS-HF)

ObjectiveThe aim of this study was to assess the predictive utility of 12-lead electrocardiogram (ECG) abnormalities among Africans with acute heart failure (HF). Methods and ResultsWe used the Sub-Saharan Africa Survey of Heart Failure, a multicenter prospective cohort study of 1,006 acute HF patients, and regression models to relate baseline ECG findings to all-cause mortality and readmission during a 6-month follow-up period. Of 814 ECGs available, 523 (49.0% male) were obtained within 15 days of admission, among which 97.7% showed abnormalities. Mean age was 52.0 years and median follow-up was 180 days, with 77 deaths (Kaplan-Meier 17.5%) through day 180 and 63 patients with death or readmission to day 60. QRS width, QT duration, bundle branch block, and ischemic changes were not associated with outcomes. Increasing ventricular rate was associated with increasing risk of both outcomes (hazard ratio [HR] 1.07 per 5 beats/min increase for 60-day death or readmission, 95% confidence interval [CI] 1.02–1.12; P = .0047), and the presence of sinus rhythm was associated with lower risk (HR 0.58, 95% CI 0.34–0.97; P = .0385). There was a strong association between survival and heart rate in patients in sinus rhythm, with heart rate >119 beats/min conveying the worst mortality risk. ConclusionsECG abnormalities are almost universal among Africans with acute HF, which may add to the immediate diagnosis of patients presenting with dyspnea. Although some ECG findings have prognostic value for risk of adverse outcomes, most of them are nonspecific and add little to the risk stratification of these patients.

A CMR study of left atrial mechanics in hypertrophic cardiomyopathy: left atrial function predicts paroxysmal atrial fibrillation

Background: Atrial fibrillation is a frequent complication in HCM, often precipitating heart failure or stroke. Identification of patients at risk of developing AF may have implications for management. While left atrial (LA) volumes have been shown to increase the risk of AF, we hypothesized that LA function is an important predictor of risk. Methods: 72 patients (36 without AF-HCM SR); 36 with PAF-HCM PAF) were compared. PAF and SR patients were matched on an individual basis for age, gender, and HCM morphology. Strain analysis with Velocity Vector Imaging software was performed on cine SSFP images obtained from CMR to assess LA volumes and function. All patients were in sinus rhythm at the time of CMR. Results: see Table. View this table: Conclusions: In HCM patients with PAF, LA function is impaired even in the presence of sinus rhythm. This difference is present even in patients with similar degrees of hypertrophy, LVOT obstruction, and mitral regurgitation, suggesting the likelihood of an underlying atrial myopathy. The presence of LA dysfunction in patients with HCM provides an incremental measure of risk of PAF over and above LA volume.

Quality of life and heart rate according to the presence of sinus rhythm or atrial fibrillation in heart failure patients

Quality of life and heart rate according to the presence of sinus rhythm or atrial fibrillation in heart failure patients

Heart rate and long-term mortality according to the presence of sinus rhythm or atrial fibrillation in heart failure patients

Heart rate and long-term mortality according to the presence of sinus rhythm or atrial fibrillation in heart failure patients

A prospective evaluation of haemodynamics, functional status, and quality of life after radiofrequency catheter ablation of long-standing persistent atrial fibrillation

Clinical benefit from ablation for long-standing persistent atrial fibrillation has remained unknown. We hypothesized that successful ablation of long-standing persistent atrial fibrillation would improve haemodynamics, functional status, and quality of life. A total of 160 patients (aged 59 ± 9 years, 23% females) undergoing ablation of long-standing (median of 28 months) persistent atrial were enrolled in this prospective study. Morphological and functional echocardiographic parameters, N-terminal prohormone of brain natriuretic peptide (NT-proBNP), maximum oxygen consumption during exercise test (VO2 max), and quality of life were assessed at baseline and 1 year after the ablation. At the 1-year follow-up visit, 81% patients were examined in sinus rhythm (after repeat ablation in 38% patients). Left atrial appendage outflow velocity increased from 44 ± 20 to 58 ± 23 cm/s, left ventricular ejection fraction from 54 ± 9 to 59 ± 5%, and VO2 max from 20.4 ± 6.4 to 23.7 ± 8.1 mL/kg/min; NT-proBNP decreased from median 897 (interquartile range 603-1424) to 230 (interquartile range 120-420) pg/mL (all P < 0.0001). These beneficial effects of ablation were predominantly associated with the presence of sinus rhythm. Quality of life (range 0-100) increased significantly (EQ-5D index: from 68.8 ± 12.5 to 75.4 ± 14.4; EQ-VAS score: from 62.8 ± 13.2 to 70.6 ± 13.8; both P < 0.0001). Ablation of long-standing persistent atrial fibrillation was associated with significant recovery of haemodynamics and exercise capacity that projected onto the long-term improvement in quality of life.

Left Atrial Contractile Function Following a Successful Modified Maze Procedure at Surgery and the Risk for Subsequent Thromboembolic Stroke

The aim of this study was to evaluate whether certain post-Maze left atrial (LA) contractile profiles may pose a risk for ischemic stroke. The mechanical contraction of the left atrium may be modified after the Maze procedure. Whether this imposes a risk for stroke, even in the presence of sinus rhythm and after removal of the LA appendage, is not known. Clinical, surgery-related, and echocardiographic data from 150 patients who underwent radiofrequency and cryoablation Maze procedures without the use of atrial incisions between 2004 and 2009 and were in sustained sinus rhythm were collected and analyzed. The occurrence of stroke was evaluated by reviewing clinical records. All stroke events were adjudicated by a neurologist. At a mean follow-up time of 24.5 months, 15 patients (10%) had experienced ischemic strokes. Forty-seven patients (31%) had no evidence of LA mechanical contraction at 3 months after surgery (baseline assessment) and on follow-up echocardiography. Multivariate analysis showed that a lack of LA mechanical contraction at baseline was associated with a 5-fold increase in the risk for stroke (p = 0.02) during follow-up. Larger atria imposed a significant risk as well; LA volume index ≥33 ml/m(2) was associated with a 3-fold risk increase (p = 0.03). These effects were maintained regardless of the lack of mechanical valve implantation and anticoagulation treatment. Absence of LA contraction and LA volume index ≥33 ml/m(2) result in a significant increase in the risk for thromboembolic stroke after the Maze procedure for patients in sinus rhythm.

Maintenance of Sinus Rhythm and Survival in Patients With Heart Failure and Atrial Fibrillation

The goal of this study was to evaluate the relationship between the presence of sinus rhythm and outcomes in patients with a history of congestive heart failure (CHF) and atrial fibrillation (AF). The value of sinus rhythm maintenance in patients with AF and heart failure (HF) is uncertain. A total of 1,376 patients with AF, ejection fraction < or =35%, and heart failure symptoms were randomized to a rhythm- or rate-control strategy. Detailed efficacy analyses were used to evaluate the independent effects of treatment strategy and the presence of sinus rhythm on cardiovascular outcomes. Overall, 445 (32%) patients died and 402 (29%) experienced worsening HF. The rhythm-control strategy was not predictive of cardiovascular mortality (hazard ratio [HR]: 0.90, 95% confidence interval [CI]: 0.70 to 1.16; p = 0.41), all-cause death (HR: 0.86, 95% CI: 0.69 to 1.08; p = 0.19), or worsening HF (HR: 0.86, 95% CI: 0.68 to 1.10; p = 0.23). In analyses devised to isolate the effect of underlying rhythm, sinus rhythm was not associated with cardiovascular mortality [HR: 1.22, 95% CI: 0.80 to 1.87; p = 0.35), total mortality [HR: 1.11, 95% CI: 0.78 to 1.58; p = 0.57), or worsening HF [HR: 0.62, 95% CI: 0.37 to 1.02; p = 0.059). A rhythm-control strategy or the presence of sinus rhythm are not associated with better outcomes in patients with AF and CHF.

How safe is the antiarrhythmic drug therapy in atrial fibrillation?

While the predominant symptom(s) related to atrial fibrillation (AF) are due to either a poorly controlled—or irregular— ventricular rate, still there is some debate with regard to the optimal strategy (that is, rate or rhythm control) to treat individual patients. Indeed, recent large, randomized, controlled trials have shown that neither rate nor rhythm control was superior in reducing mortality in AF patients, although achieving rhythm control appears to improve functional class, 1 at least in the short term. Interestingly, a post hoc analysis from the AFFIRM trial found that sinus rhythm (and warfarin use) was related to improved survival but this was offset by a greater mortality from antiarrhythmic drugs (AADs). 2 Anderson et al., 3 from a large retrospective (n ¼ 40 823) Swedish nationwide study (conducted between 1995 and 2004), reported that AAD therapy was not associated with an increased mortality in AF patients. As expected, various AADs (mainly flecainide, propafenone, sotalol, and amiodarone) were used in the treatment of AF, but in this unselected, non-randomized cohort, considerably more patients were on sotalol (16%) when compared with the rest of the AADs (flecainide 2.4%, propafenone 2.6%, or amiodarone 7.3%). However, in patients with previous myocardial infarction (MI) or ischaemic heart disease, the preferred choice of AAD was amiodarone (24.3%) compared with sotalol (15%) or class-Ic drugs (8.6%). Similarly, more patients with heart failure were on amiodarone (21.5%) when compared with other AADs (sotalol 9.5%, class-Ic drugs 6.1%). The authors quoted annual mortality rates (per year/100 patient-years) of 7.4 vs. 5.3% vs. 4.3% vs. 2.5% with amiodarone, sotalol, propafenone and flecainide, respectively. Approximately a third of these unselected patients were noted to be on digoxin, whilst a fifth were on betablockers or calcium blockers—on top of prescribed AAD therapy for AF. In a Cox-regression analysis, treatment with AAD was generally associated with a lower mortality (flecainide HR 0.38, 95% CI 0.32‐0.44; propafenone HR 0.65, 95% CI 0.58‐0.71; sotalol HR 0.65, 95% CI 0.63‐0.67) but the effect of amiodarone was borderline (HR 0.94, 95% CI 0.89‐1.00). Perhaps AADs may be safe in AF after all? The quoted mortality in the paper by Anderson et l. 3 with individual AADs may well be related to disease progression rather than effect of antiarrhythmic therapy per se, and cause(s) of death in these patients is not that clear. But also, the choice of AADs were carefully selected in individual patients which also might account for the observed low mortality. These observations are contrary to the post hoc analysis of AFFIRM trial data 2,4 that there was a non-significant trend towards a higher mortality in patients assigned to rhythm when compared with rate control, predominantly due to noncardiovascular causes. The significant predictors of higher noncardiovascular mortality on multivariate analysis were rhythm control, male gender, heart failure, age, and coronary artery disease. Nevertheless, this increased mortality seen in rhythm control group may well be related to adverse effects of the various AADs used (amiodarone, sotalol, disopyramide, flecainide, moricizine, procainamide, propafenone, and quinidine) in these AF patients without heart failure, although the precise mechanism(s) was not well elucidated. In a subsequent analysis using time-dependent variables towards in these patients, there was a 1.5-fold increased risk of death noted with AAD therapy after adjusting to co-variables in the presence of sinus rhythm (HR 1.49, 99% CI 1.11‐2.01). 4 The use of digoxin for rate control also appears to increase the risk of death (HR 1.42, 99% CI 1.18‐1.89) in these patients with persistent AF. 2,4 Notably, neither beta-blockers nor calcium-channel blockers had any effect on improving survival of these AF patients. Broadly similar results were noted in the Stroke Prevention in Atrial Fibrillation (SPAF) 5 trial, where there was a 2.5-fold increase in cardiac mortality (HR 2.5, 95%CI 1.3‐4.9) and a 2.6-fold increase in arrhythmic deaths (HR 2.6, 95% CI 1.2‐5.6) in AF patients on AAD therapy, even after adjusting for cardiovascular risk factors. However, AF patients with history of congestive heart failure

Current controversies in using electrical devices

Current controversies in using electrical devices

Reproducibility of Electrocardiographic Findings in Patients With Suspected Reflex Neurally-Mediated Syncope

The reproducibility of electrocardiographic (ECG) recordings in syncopal recurrences and the diagnostic role of nonsyncopal arrhythmias are not well known. The objective of this study was to analyse the reproducibility of the ECG findings recorded with implantable loop recorders in 41 patients with suspected neurally-mediated syncope who were included in the International Study on Syncope of Uncertain Origin-2 study and that had > or =2 events recorded by implantable loop recorders. In these patients, the electrocardiogram obtained with the first documented syncope (index syncope) was compared with other recorded events. Twenty-two patients had > or =2 syncopes, and their electrocardiograms were reproducible in 21 (95%): 15 with sinus rhythm, 5 with asystole, and 1 with ventricular tachycardia; 1 had asystole at first syncope and sinus rhythm at recurrent syncope. In 32 patients with nonsyncopal episodes, an arrhythmia was documented in 9, and all of them had the same arrhythmia during the index syncope (100% reproducibility); conversely, when sinus rhythm was documented (23 patients) during nonsyncopal episodes, an arrhythmia was still documented in 6 during the index syncope (70% reproducibility; p = 0.0004). In conclusion, the ECG findings during the first syncope are highly reproducible in subsequent syncopes. The presence of an arrhythmia during nonsyncopal episodes is also highly predictive of the mechanism of syncope, but the presence of sinus rhythm does not rule out the possibility of arrhythmia during syncope. Therefore the finding of an arrhythmia during a nonsyncopal episode allows the etiologic diagnosis of syncope, and eventually to anticipate treatment, without waiting for syncope.

Echocardiographic Evaluation of a TASER‐X26 Application in the Ideal Human Cardiac Axis

TASER electronic control devices (ECDs) are used by law enforcement to subdue aggressive persons. Some deaths temporally proximate to their use have occurred. There is speculation that these devices can cause dangerous cardiac rhythms. Swine research supports this hypothesis and has reported significant tachyarrhythmias. It is not known if this occurs in humans. The objective of this study was to determine the occurrence of tachyarrhythmias in human subjects subjected to an ECD application. This was a prospective, nonblinded study. Human volunteers underwent limited echocardiography before, during, and after a 10-second TASER X26 ECD application with preplaced thoracic electrodes positioned in the upper right sternal border and the cardiac apex. Images were analyzed using M-mode through the anterior leaflet of the mitral valve for evidence of arrhythmia. Heart rate (HR) and the presence of sinus rhythm were determined. Data were analyzed using descriptive statistics. A total of 34 subjects were enrolled. There were no adverse events reported. The mean HR prior to starting the event was 108.7 beats/min (range 65 to 146 beats/min, 95% CI = 101.0 to 116.4 beats/min). During the ECD exposure, the mean HR was 120.1 beats/min (range 70 to 158 beats/min, 95% CI = 112.2 to 128.0 beats/min) and a mean of 94.1 beats/min (range 55 to 121 beats/min, 95% CI = 88.4 to 99.7 beats/min) at 1 minute after ECD exposure. Sinus rhythm was clearly demonstrated in 21 (61.7%) subjects during ECD exposure (mean HR 121.4 beats/min; range 75 to 158 beats/min, 95% CI = 111.5 to 131.4). Sinus rhythm was not clearly demonstrated in 12 subjects due to movement artifact (mean HR 117.8 beats/min, range 70 to 152 beats/min, 95% CI = 102.8 to 132.8 beats/min). A 10-second ECD exposure in an ideal cardiac axis application did not demonstrate concerning tachyarrhythmias using human models. The swine model may have limitations when evaluating ECD technology.