ACC/AHA/ESC Guidelines for the Management of Patients With Supraventricular Arrhythmias—Executive Summary

Cryoablation Versus Radiofrequency Ablation in the Management of Pediatric Supraventricular Tachyarrhythmia: A Systematic Review and Meta-Analysis

Supraventricular tachycardia (SVT) is a common arrhythmia in pediatric patients, often requiring catheter ablation for effective treatment. Two primary techniques, radiofrequency ablation (RFA) and cryoablation (CA), are widely used; however, their comparative safety and efficacy remain subjects of debate, with no clear consensus on the preferred approach. This systematic review and meta-analysis aimed to evaluate and compare the efficacy and safety of RFA and CA in pediatric patients with SVT, focusing on the primary outcomes of acute success and recurrence rates. The study was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Eligible studies included comparative analyses such as randomized controlled trials, non-randomized trials, and observational studies that specifically evaluated RFA and CA in pediatric populations with SVT. Exclusion criteria included studies involving adult populations, those without comparative groups, case reports, case series, and conference abstracts. Data extracted from the included studies encompassed acute success rates, recurrence rates, and complication rates, providing a comprehensive overview of the performance and safety profiles of RFA and CA in this patient group. Acute success rates were high for both techniques (RFA: 96.3%, CA: 94.9%; p = 0.137). However, RFA demonstrated a significantly lower recurrence rate (7.9% vs. 14.4%; odds ratio (OR): 0.408, 95% CI: 0.242-0.689, p < 0.001). CA was associated with longer procedure durations (mean difference: 9.684 minutes, p = 0.437) and significantly reduced fluoroscopy times (mean difference: 6.566 minutes, p = 0.032). Complication rates were comparable, with a non-significant trend favoring RFA (OR: 0.363, p = 0.112). Overall, both RFA and CA were found to be effective and safe for pediatric SVT. RFA offers durable results with lower recurrence rates, while CA minimizes fluoroscopy time, thereby reducing radiation exposure. Treatment selection should be individualized, considering factors such as the type and location of the arrhythmia as well as specific procedural risks.

What an anesthesiologist should know about pediatric arrhythmias

Identifying and treating pediatric arrhythmias is essential for pediatric anesthesiologists. Pediatric patients can present with narrow or wide complex tachycardias, though the former is more common. Patients with inherited channelopathies or cardiomyopathies are at increased risk. Since most pediatric patients present for anesthesia without a baseline electrocardiogram, the first identification of an arrhythmia may occur under general anesthesia. Supraventricular tachycardia, the most common pediatric tachyarrhythmia, represents a broad category of predominately narrow complex tachycardias. Stimulating events including intubation, vascular guidewire manipulation, and surgical stimulation can trigger episodes. Valsalva maneuvers are unreliable as treatment, making adenosine or other intravenous antiarrhythmics the preferred acute therapy. Reentrant tachycardias are the most common supraventricular tachycardia in pediatric patients, including atrioventricular reciprocating tachycardia (due to a distinct accessory pathway) and atrioventricular nodal reentrant tachycardia (due to an accessory pathway within the atrioventricular node). Patients with ventricular preexcitation, often referred to as Wolff-Parkinson-White syndrome, have a wide QRS with short PR interval, indicating antegrade conduction through the accessory pathway. These patients are at risk for sudden death if atrial fibrillation degenerates into ventricular fibrillation over a high-risk accessory pathway. Automatic tachycardias, such as atrial tachycardia and junctional ectopic tachycardia, are causes of supraventricular tachycardia in pediatric patients, the latter most typically noted after cardiac surgery. Patients with inherited arrhythmia syndromes, such as congenital long QT syndrome, are at risk of developing ventricular arrhythmias such as polymorphic ventricular tachycardia (Torsades de Pointes) which can be exacerbated by QT prolonging medications. Patients with catecholaminergic polymorphic ventricular tachycardia are at particular risk for developing bidirectional ventricular tachycardia or ventricular fibrillation during exogenous or endogenous catecholamine surges. Non-selective beta blockers are first line for most forms of long QT syndrome as well as catecholaminergic polymorphic ventricular tachycardia. Anesthesiologists should review the impact of medications on the QT interval and transmural dispersion of repolarization, to limit increasing the risk of Torsades de Pointes in patients with long QT syndrome. This review explores the key anesthetic considerations for these arrhythmias.

Atrial tachycardia originating from a right atrial free wall diverticulum: case report

Background

Atrial tachycardia (AT) is an arrhythmic disorder originating from the atrium, independent of the atrioventricular node, and includes various types based on different mechanisms such as abnormal automaticity, triggered activity, and re-entry. These mechanisms are often related to specific anatomical structures. Focal AT, though relatively rare, typically arises from well-known locations in the left and right atria, such as the pulmonary veins, mitral valve annulus, crista terminalis, and coronary sinus ostium.

Case summary

We report a rare case of AT originating from a diverticulum in the right atrial free wall. The patient experienced recurrent AT episodes resistant to standard treatments. Detailed electrophysiological mapping identified the unusual origin of the tachycardia from a right atrial free wall diverticulum. Catheter ablation was successfully performed, leading to the resolution of the arrhythmia, with the patient remaining symptom-free during follow-up.

Discussion

This case expands the understanding of AT origins, highlighting the right atrial free wall diverticulum as a potential, though rare, source of tachycardia. The case emphasizes the importance of comprehensive electrophysiological mapping, especially in atypical presentations of AT. Successful ablation in this instance underscores the potential for targeted interventions even in uncommon anatomical sites. Further studies are needed to assess the prevalence and clinical significance of AT arising from such rare locations.

Cardiovascular complications during pregnancy: Advancing cardio-obstetrics

As the incidence of cardiovascular diseases (CVDs) continues to rise among women of childbearing age, the pregnant population with pre-existing heart conditions presents a complex and heterogeneous profile. These women face varying degrees of risk concerning maternal cardiovascular, obstetric, and fetal complications. Effectively managing adverse cardiovascular events during pregnancy presents substantial clinical challenges. The uncertainties surrounding diagnostic and therapeutic approaches create a dynamic landscape with potential implications for maternal and fetal health. Cardio-obstetrics has become increasingly recognized as a vital multidisciplinary field necessitating a collaborative approach to managing cardiovascular conditions during pregnancy. In this review, we aim to provide a thorough and up-to-date examination of the existing evidence, offering a comprehensive overview of strategies and considerations in the management of cardiovascular complications during pregnancy. Special emphasis is placed on the safety assessment of diagnostic procedures and the exploration of treatment options designed to prioritize the well-being of the mother and fetus. We also explore the significance of a multidisciplinary cardio-obstetrics team in providing comprehensive care for women of childbearing age with or at risk for CVD.

Two decades of SVT ablation in Denmark: a trend towards higher age, more comorbidity, and less prior use of antiarrhythmic and rate-limiting pharmacotherapy-a nationwide registry-based Danish study

BACKGROUND AND AIMS

Trends in patient selection and use of pharmacotherapy prior to catheter ablation (CA) for supraventricular tachycardia (SVT) are not well described. This study examined temporal trends in patients undergoing first-time CA for regular SVT, including atrioventricular nodal re-entry tachycardia (AVNRT), accessory pathways (APs), and ectopic atrial tachycardia (EAT) on a nationwide scale in Denmark in the period 2001-2018.

METHODS AND RESULTS

Using Danish Nationwide registers, 9959 patients treated with first-time CA for SVT between 2001 and 2018 were identified, of which 6023 (61%) received CA for AVNRT, 2829 (28%) for AP, and 1107 (11%) for EAT. Median age was 55, 42, and 55 in the AVNRT, APs, and EAT group, respectively. The number of patients receiving CA increased from 1195 between 2001 and 2003 to 1914 between 2016 and 2018. The percentage of patients with a CHA2DS2-VASc score ≥ 2 increased in all patient groups. The number of patients who underwent CA with no prior use of antiarrhythmic- or rate limiting medicine increased significantly, though prior use of beta-blockers increased for AVNRT patients. Use of verapamil decreased in all three SVT groups (P < 0.05). Use of amiodarone and class 1C antiarrhythmics remained low, with the highest usage among EAT patients.

CONCLUSION

Between 2001 and 2018, CA was increasingly performed in patients with SVT, primarily AVNRT- and EAT patients. The burden of comorbidities increased. Patients undergoing CA without prior antiarrhythmic- or rate-limiting drug therapy increased significantly. Use of beta-blockers increased and remained the most widely used drug.

Simple Criteria, Yet the Dearth Utilization-Antithrombotic Management Practice among Atrial Fibrillation Patients at Hawassa University Comprehensive Specialized Hospital, Hawassa, Sidama, Ethiopia

Background

Atrial fibrillation (AF) is associated with significant mortality and morbidity from stroke and thromboembolism. Despite the availability of effective oral anticoagulation medication, AF patients remain at a high risk of stroke if not treated properly. The purpose of this study was to evaluate antithrombotic therapy practices in patients with AF in the adult cardiac clinic at Hawassa University Comprehensive Specialized Hospital (HUCSH).

Methods

It was a retrospective document review study. Total charts of 119 patients who had follow-up at the adult cardiac clinic with a history of documented AF from January 1 to December 30, 2018, were included. Indicators for antithrombotic therapy based on the congestive heart failure, hypertension, age ≥75 (doubled), diabetes, stroke (doubled), vascular disease, age 65 to 74, and sex category (female) (CHA2DS2-VASc) score were recorded. A p value of 0.05 was considered statistically significant. Data analysis was done using SPSS 23 software.

Results

In this study, about 55% of patients with AF were receiving the appropriate antithrombotic treatment. The patients were 48 ± 18.2 years old. Of these, 70% were women. The most frequent underlying cardiac etiology was chronic rheumatic valvular heart disease (50%), followed by cardiomyopathy (14%). In nonvalvular AF, the mean CHA2DS2VASc score was 4.0 ± 1.07. In valvular AF compared to nonvalvular AF, the need for appropriate antithrombotic therapy was substantially greater (p 0.0001). Only 8 (13.6%) of the warfarin-using patients had adequate anticoagulation.

Conclusion

The study's findings in regard to antithrombotic usage and maintenance of appropriate antithrombotics for stroke prevention in our patients revealed a discrepancy between recommendations and practice. Therefore, we demand that patients with AF who meet the criteria utilize antithrombotics properly to prevent stroke. Warfarin-taking patients' subpar optimum anticoagulation has to be addressed. Lastly, we advocate proper CHA2DS2-VASc score utilization for nonvalvular heart disease. A regular INR follow-up is also advised for patients who have started taking warfarin.

A Twenty-Year Follow-Up of Adults with Ebstein Anomaly with Special Focus on Supraventricular Arrhythmias, Supraventricular Arrhythmias and Effectiveness of Catheter Ablation in 20-Year Follow-Up of Adults with Ebstein Anomaly

Background: Ebstein anomaly (EA) is a rare congenital heart disease characterized by the apical displacement of the tricuspid leaflets, creating an enlarged functional right atrium. Supraventricular arrhythmias (SVA) are common, and catheter ablation remains challenging. SVA is considered a risk factor for sudden cardiac death in this population. Still, there are very few real-life data on the impact of SVA treated invasively or conservatively on a patient's prognosis. We aimed to analyze the incidence of SVA in adults with EA, evaluate the effectiveness of catheter ablation, and analyze the impact of SVA and catheter ablation on survival in this population. Methods and results: 71 pts (median age 53 years; range 24-84 years) with EA were evaluated retrospectively from 1988 to 2020. Forty patients (56.3%) had SVA, and eighteen of them (45.0%) required at least one catheter ablation (35 procedures in total). Indications for ablation were mostly intra-atrial reentrant tachycardia (IART) and atrioventricular reentrant tachycardia (AVRT) (14 pts [77.8% and 9 pts [50.0%], respectively. IART and AVRT coexisted in nine pts. One patient suffered from persistent atrial fibrillation. Procedural effectiveness was reported in 28 (80%) cases; over a longer follow-up (mean 12.6 ± 5.4 years), only eight (44.4%) patients were completely free from SVA after the first ablation. In total, 10 patients (14%) died due to cardiovascular events. There was no difference in survival between patients with or without SVA (p = 0.9) and between ablated and non-ablated EA individuals (p = 0.89). Conclusions: Supraventricular arrhythmia is frequent in adults with Ebstein anomaly. Patients often require more than one catheter ablation but eventually become free from arrhythmias. The imaging parameters assessed by echocardiography or cardiac magnetic resonance do not seem to be associated with ablation outcomes. The impact of supraventricular arrhythmia itself or treatment with radiofrequency ablation is questionable and should be thoroughly investigated in this population.

Wolf-Parkinson-White Syndrome: Diagnosis, Risk Assessment, and Therapy-An Update

Wolf-Parkinson-White (WPW) syndrome is a disorder characterized by the presence of at least one accessory pathway (AP) that can predispose people to atrial/ventricular tachyarrhythmias and even sudden cardiac death. It is the second most common cause of paroxysmal supraventricular tachycardia in most parts of the world, affecting about 0.1-0.3% of the general population. Most patients with WPW syndrome have normal anatomy, but it may be associated with concomitant congenital heart disease or systemic diseases. Although many individuals are asymptomatic, during supraventricular arrhythmia episodes, they may experience severe symptoms, including syncope or even sudden cardiac death (mainly due to pre-excited atrial fibrillation over rapidly conducting AP). In addition to arrhythmia-related symptoms, for some specific locations of the APs with overt anterograde conduction, there might be a reduction in exercise capacity mediated by a reduction in LV systolic performance due to anomalous LV depolarization. Although it is typically diagnosed through electrocardiography (ECG), additional tests are necessary for risk assessment. Management of WPW syndrome may be quite challenging and can vary from only acknowledging the presence of the accessory pathway to pharmacological treatment or radiofrequency ablation. Early diagnosis, risk assessment, and appropriate treatment are critical steps in the management of WPW syndrome, aiming to improve the quality of life and reduce the risk of life-threatening arrhythmias.

Acute Effects of Coffee Consumption on Health among Ambulatory Adults

BACKGROUND

Coffee is one of the most commonly consumed beverages in the world, but the acute health effects of coffee consumption remain uncertain.

METHODS

We conducted a prospective, randomized, case-crossover trial to examine the effects of caffeinated coffee on cardiac ectopy and arrhythmias, daily step counts, sleep minutes, and serum glucose levels. A total of 100 adults were fitted with a continuously recording electrocardiogram device, a wrist-worn accelerometer, and a continuous glucose monitor. Participants downloaded a smartphone application to collect geolocation data. We used daily text messages, sent over a period of 14 days, to randomly instruct participants to consume caffeinated coffee or avoid caffeine. The primary outcome was the mean number of daily premature atrial contractions. Adherence to the randomization assignment was assessed with the use of real-time indicators recorded by the participants, daily surveys, reimbursements for date-stamped receipts for coffee purchases, and virtual monitoring (geofencing) of coffee-shop visits.

RESULTS

The mean (±SD) age of the participants was 39±13 years; 51% were women, and 51% were non-Hispanic White. Adherence to the random assignments was assessed to be high. The consumption of caffeinated coffee was associated with 58 daily premature atrial contractions as compared with 53 daily events on days when caffeine was avoided (rate ratio, 1.09; 95% confidence interval [CI], 0.98 to 1.20; P = 0.10). The consumption of caffeinated coffee as compared with no caffeine consumption was associated with 154 and 102 daily premature ventricular contractions, respectively (rate ratio, 1.51; 95% CI, 1.18 to 1.94); 10,646 and 9665 daily steps (mean difference, 1058; 95% CI, 441 to 1675); 397 and 432 minutes of nightly sleep (mean difference, 36; 95% CI, 25 to 47); and serum glucose levels of 95 mg per deciliter and 96 mg per deciliter (mean difference, -0.41; 95% CI, -5.42 to 4.60).

CONCLUSIONS

In this randomized trial, the consumption of caffeinated coffee did not result in significantly more daily premature atrial contractions than the avoidance of caffeine. (Funded by the University of California, San Francisco, and the National Institutes of Health; CRAVE ClinicalTrials.gov number, NCT03671759.).

Heart Disease and Stroke Statistics-2023 Update: A Report From the American Heart Association

BACKGROUND

The American Heart Association, in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The American Heart Association, through its Epidemiology and Prevention Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update with review of published literature through the year before writing. The 2023 Statistical Update is the product of a full year's worth of effort in 2022 by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. The American Heart Association strives to further understand and help heal health problems inflicted by structural racism, a public health crisis that can significantly damage physical and mental health and perpetuate disparities in access to health care, education, income, housing, and several other factors vital to healthy lives. This year's edition includes additional COVID-19 (coronavirus disease 2019) publications, as well as data on the monitoring and benefits of cardiovascular health in the population, with an enhanced focus on health equity across several key domains.

RESULTS

Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Association of Coffee Consumption With Atrial Fibrillation Risk: An Updated Dose-Response Meta-Analysis of Prospective Studies

BACKGROUND

Several published studies have examined the association of coffee consumption with atrial fibrillation (AF) risk, but their findings are still controversial. Therefore, we performed a systematic review and dose-response meta-analysis of prospective studies to determine the relationship between coffee consumption and the risk of incident AF.

METHODS

We systematically retrieved the PubMed and Embase databases until October 2021 for pertinent studies that reported the association of coffee consumption (caffeinated or decaffeinated coffee) with AF risk. A cubic spline random-effects model was used to fit the potential dose-response curve. The effect estimates were expressed as adjusted risk ratios (RRs) and 95% CIs.

RESULTS

A total of 10 prospective studies (11 cohorts) involving 30,169 AF events and 723,825 participants were included. In the dose-response analysis, there was a linear inverse association between coffee intake and risk of AF although not statistically significant (P non-linearity = 0.25). Compared with participants with no coffee consumption, the RRs (95% CI) of AF risk estimated directly from the dose-response curve were 1.01 (0.98-1.03), 1.00 (0.97-1.04), 0.99 (0.92-1.02), 0.95 (0.89-1.01), 0.94 (0.87-1.01), 0.89 (0.79-1.02), and 0.87 (0.76-1.02) for 1-7 cups of coffee per day, respectively. One cup per day increased in coffee consumption was associated with a 2% reduced risk of AF (RR = 0.98, 95% CI: 0.97-1.00, P = 0.02).

CONCLUSIONS

Our evidence from this meta-analysis suggested that coffee consumption had a trend toward reducing the risk of AF in a dose-response manner. Further studies could be conducted to reinforce our findings.

Deep Vein Thrombosis is Common After Cardiac Ablation and Pre-Procedural D-Dimer Could Predict Risk

PURPOSE

Cardiac catheter ablations are an established treatment for supraventricular tachycardia (SVT) involving prolonged cannulation of the common femoral vein with multiple catheters. This study aimed to identify the risk of deep vein thrombosis (DVT) by studying the frequency of this complication after catheter ablation.

METHODS

This was a prospective multi-centre cohort study of patients undergoing cardiac ablation for atrioventricular nodal re-entry tachycardia or right-sided accessory atrioventricular connection. Those taking anticoagulation or antiplatelet therapy prior to the procedure were excluded. Following the procedure, bilateral venous duplex ultrasonography from the popliteal vein to the inferior vena cava for DVT was undertaken at 24 hours and between 10 to 14 days.

RESULTS

Eighty (80) patients (mean age 47.6 yrs [SD 13.4] with 67% female) underwent cardiac ablation (median duration 70 mins). Seven (7) patients developed acute DVT in either the femoral or external iliac vein of the intervention leg, giving a frequency of 8.8% (95% CI 3.6-17.2%). No thrombus was seen in the contralateral leg (p=0.023). An elevated D-dimer prior to the procedure was significantly more frequent in patients developing DVT (42.9% vs 4.1%, p=0.0081; OR 17.0). No other patient or procedural characteristics significantly influenced the risk of DVT.

CONCLUSION

In patients without peri-procedural anticoagulation catheter ablation precipitated DVT in the catheterised femoral or iliac veins in 8.8% of patients. Peri-procedure prophylactic anticoagulation may be considered for all patients undergoing catheter ablation for SVT.

CLINICAL TRIAL REGISTRATION

https://clinicaltrials.gov/ct2/show/NCT03877770.

Heart Disease and Stroke Statistics-2022 Update: A Report From the American Heart Association

BACKGROUND

The American Heart Association, in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The American Heart Association, through its Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update. The 2022 Statistical Update is the product of a full year's worth of effort by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. This year's edition includes data on the monitoring and benefits of cardiovascular health in the population and an enhanced focus on social determinants of health, adverse pregnancy outcomes, vascular contributions to brain health, and the global burden of cardiovascular disease and healthy life expectancy.

RESULTS

Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Clinical Characteristics of Patients with Tetralogy of Fallot who Underwent an Invasive Procedure for Arrhythmias

Introduction: Tetralogy of Fallot (TOF) is a cyanotic congenital heart disease that has an incidence of sudden cardiac death of 0.2% per year, being arrhythmias the main cause of its occurrence. Objective: To compare characteristics of TOF patients referred for electrophysiological study (EPS) against those that were not (No-EPS). Method: Retrospective cohort with 215 patients (57.2% men; age = 29 ± 4) with corrected TOF (median of three years, ranging from 0.33 to 51) that underwent EPS between 2009-2020. The primary outcome was composed of death, implantable cardiac defibrillator (ICD) requirement and hospitalization. Results: Pre-syncope (EPS = 4.7%, No-EPS = 0%; p = 0.004), syncope (EPS = 7.1%, No-EPS = 1.7%; p = 0.056) and palpitations (EPS = 31%, No-EPS = 5.8%; p < 0.001) were symptoms that justified electrophysiological investigation. ICD was implanted in 24% of EPS and 0.6% of No-EPS (p=0.001). Twenty-six percent of the EPS group presented non-sustained ventricular tachycardia, while 0% in No-EPS (p = 0.012). The EPS group had more atrial fibrillation or atrial Flutter (35.7% vs. 6.9%; p < 0.001). The EPS patients had a wider QRS duration than the no-EPS group (171.12 ± 29.52 ms vs. 147 ± 29.77 ms; p < 0.001). Also, 26.2% of EPS performed ablation to correct macroreentrant atrial tachycardias. The incidence of primary outcome (death + ICD requirement + hospitalization) was higher in patients in the EPS group compared to the No-EPS group (p = 0.001). However, the total of seven deaths occurred during the clinical follow-up, but without differences between the groups (EPS = 4.7% vs. No-EPS = 2.8%; p = 0.480). Conclusion: EPS group had a profile of greater risk, more complex heart disease, and a greater occurrence of the primary outcome when compared to the No-EPS group.

Coffee Consumption and Incident Tachyarrhythmias: Reported Behavior, Mendelian Randomization, and Their Interactions

Importance

The notion that caffeine increases the risk of cardiac arrhythmias is common. However, evidence that the consumption of caffeinated products increases the risk of arrhythmias remains poorly substantiated.

Objective

To assess the association between consumption of common caffeinated products and the risk of arrhythmias.

Design, Setting, and Participants

This prospective cohort study analyzed longitudinal data from the UK Biobank between January 1, 2006, and December 31, 2018. After exclusion criteria were applied, 386 258 individuals were available for analyses.

Exposures

Daily coffee intake and genetic polymorphisms that affect caffeine metabolism.

Main Outcomes and Measures

Any cardiac arrhythmia, including atrial fibrillation or flutter, supraventricular tachycardia, ventricular tachycardia, premature atrial complexes, and premature ventricular complexes.

Results

A total of 386 258 individuals (mean [SD] age, 56 [8] years; 52.3% female) were assessed. During a mean (SD) follow-up of 4.5 (3.1) years, 16 979 participants developed an incident arrhythmia. After adjustment for demographic characteristics, comorbid conditions, and lifestyle habits, each additional cup of habitual coffee consumed was associated with a 3% lower risk of incident arrhythmia (hazard ratio [HR], 0.97; 95% CI, 0.96-0.98; P < .001). In analyses of each arrhythmia alone, statistically significant associations exhibiting a similar magnitude were observed for atrial fibrillation and/or flutter (HR, 0.97; 95% CI, 0.96-0.98; P < .001) and supraventricular tachycardia (HR, 0.96; 95% CI, 0.94-0.99; P = .002). Two distinct interaction analyses, one using a caffeine metabolism-related polygenic score of 7 genetic polymorphisms and another restricted to CYP1A2 rs762551 alone, did not reveal any evidence of effect modification. A mendelian randomization study that used these same genetic variants revealed no significant association between underlying propensities to differing caffeine metabolism and the risk of incident arrhythmia.

Conclusions and Relevance

In this prospective cohort study, greater amounts of habitual coffee consumption were associated with a lower risk of arrhythmia, with no evidence that genetically mediated caffeine metabolism affected that association. Mendelian randomization failed to provide evidence that caffeine consumption was associated with arrhythmias.

Successful risk stratification of a patient with ventricular preexcitation by improved transesophageal electrophysiological study

The patient is a 19 years‐old man who often wakes up in dreams with palpitations and fatigue. The ECG shows: 1. Sinus rhythm; 2. Preexcitation syndrome. Transesophageal electrophysiological study (TEEPS) diagnosis:High‐risk accessory pathway. During radiofrequency catheter ablation, the patient suddenly developed atrial fibrillation and quickly converted to ventricular fibrillation. After defibrillation, ventricular fibrillation is transformed into sinus rhythm. Subsequently, the patient's high‐risk accessory pathway was successfully ablated. Studies have shown that about 25% of patients with WPW syndrome have a refractory period of less than 250 ms, which is one of the risk factors for the conversion of atrial fibrillation to ventricular fibrillation. Therefore, risk stratification is recommended for these symptomatic patients. From 1980 to 1990, there were literature reports on risk stratification of patients with preexcitation syndrome by TEEPS. But it has not become a routine examination of risk stratification in patients with preexcitation syndrome.The reason may be related to the hardware conditions and risk stratification methods used at that time. The TEEPS equipment currently used in our hospital can control the pacing voltage at about 12 mv on average. The voltage in this case report is 9 mv only. In addition, we successfully stratified the risk of patient with preexcitation syndrome without inducing atrial fibrillation. All the electrophysiological records of the patient during the examination were recorded simultaneously with the 12‐lead ECG and the esophageal lead ECG. These improvements makes TEEPS a simple, safe and reliable non‐invasive cardiac electrophysiological detection technology, which is worth popularizing in hospitals.

Cross-ethnic comparison of the association between central sleep apnea and atrial fibrillation/flutter: The Kuakini Honolulu-Asia Aging Study and the Osteoporotic Fractures in Men (Mr.OS) study

Introduction

Few studies indicated the impact of ethnicity on an association between central sleep apnea (CSA) and atrial fibrillation/flutter (AF) in older populations. We assessed possible ethnic differences in the association among elderly Japanese-American and White-American men.

Methods

We performed a cross-sectional analysis using two population studies of Japanese-American and White-American men. The Kuakini Honolulu-Asia Aging Study is a longitudinal cohort study of Japanese-American men living in Hawaii. Sleep data were collected between 1999 and 2000. The Osteoporotic Fractures in Men (Mr.OS) Sleep Study was conducted between 2003 and 2005 on the continental U.S. The majority of Mr.OS participants were White-American. We selected 79-90 year old males, who had overnight polysomnography from both studies. Total participants were 690 Japanese-American and 871 White-American men. The central apnea index (CAI) was the measure of the number of central apneas. CSA was defined by CAI>=5. Cheyne-Stokes breathing (CSB) was defined as a minimum consecutive 5-10 min period of a crescendo-decrescendo respiratory pattern associated with CSA.

Results

The prevalence of AF was 5.7% in Japanese-American men and 9.0% in White-American men. The prevalence of CSA and CSB in White-Americans were higher than in Japanese-Americans (11.5% vs 6.5% and 5.7% vs 3.3%, respectively). In multivariable-adjusted logistic regression models, CSA was associated with higher odds of AF, and the association was stronger in Japanese-Americans [Odds Ratio (OR) = 4.77, 95% confidence interval (CI): 1.95-11.67] than in White-Americans (OR = 2.09, 95 %CI: 1.09-4.01). CSB showed similar trends as CSA.

Conclusions

After adjustment, CSA and CSB were significantly associated with AF in both Japanese-American and White-American men.

Efficacy and safety of the application of extensive ablation in patients with atrioventricular re-entrant tachycardia (a retrospective study)

Radiofrequency catheter ablation (RFCA) has become the standard effective therapy for supraventricular tachycardia, but the reported success rates of ablation have differed across a large number of single-center studies. The main reason for tachycardia recurrence is accessory pathway (Ap)-mediated tachycardia, and the use of the RFCA strategy may be related to recurrence. This study compared the efficacy and safety of two different RFCA strategies for Ap-mediated tachycardia. We compared patients (group M) who underwent RFCA at multiple sites to patients (group S) who underwent RFCA at a single site during the index procedure for Ap-mediated tachycardia. The efficacy and safety were assessed in the two groups. Follow-up was conducted, and the main complications and the incidence of recurrence after RFCA procedures were recorded. Eight hundred eighty-two patients with 898 Aps were enrolled in group S, and 830 patients with 843 Aps were enrolled in group M. The cumulative number of recurrences (rates) in group M and group S at the 1st, 3rd, 6th, 12th, and 24th months after ablation were 4 (0.5%) and 17 (1.9%), p < 0.05; 5 (0.6%) and 27 (3.0%), p < 0.05; 6 (0.7%) and 34 (3.8%), p < 0.05; 6 (0.7%) and 43 (4.8%), p < 0.05; and 7 (0.8%) and 45 (5.0%), p < 0.05, respectively. Complications of chest pain, overactive vasovagal reaction, steam pop, and angina pectoris were rare in both groups. One patient in group M suffered from myocardial infarction before extensive ablation. No valve damage, cardiac tamponade, or other serious adverse events occurred in either group. The extensive ablation strategy reduced the recurrence rate and the need for subsequent ablation of the Ap without increasing the risk of complications.

Long-term outcomes of self-expanding versus balloon-expandable transcatheter aortic valves: Insights from the OBSERVANT study

OBJECTIVES

To compare clinical outcomes of balloon-expandable (BE) and self-expanding (SE) transcatheter aortic valves (TAVs) up to 5 years.

BACKGROUND

To date, no robust, comparative data of BE and SE TAVs at long-term are available.

METHODS

We considered a total of 1,440 patients enrolled in the multicenter OBSERVANT study and undergoing transfemoral transcatheter aortic valve implantation (TF-TAVI) with either supra-annular SE (n = 830, 57.6%) and intra-annular BE (n = 610, 42.4%) valves. Clinical outcomes of the two groups were compared after adjustment using inverse probability of treatment weighting (IPTW) and confirmed by sensitivity analysis with propensity score matching.

RESULTS

Patients receiving SE valve showed a higher all-cause mortality at 5 years (Kaplan-Meier estimates 52.3% vs. 47.7%; Hazard ratio [HR] 1.18, 95% confidence interval [CI] 1.01-1.38, p = .04). Landmark analyses showed that there was a not statistically significant reversal of risk excess against the BE group starting from 3 years after TAVI (3-5 years HR 0.97, 95% CI 0.76-1.25, p = .86). Post-procedural, moderate/severe paravalvular regurgitation (PVR)(HR 1.46, 95% CI 1.14-1.87; p < .01) and acute kidney injury (AKI)(HR 3.89, 95% CI 2.47-6.38; p < .01) showed to be independent predictors of 5-year all-cause mortality in multivariable analysis.

CONCLUSIONS

Considering the intrinsic limitations of the OBSERVANT study, we found that patients undergoing TF-TAVI with a supra-annular SE valve had a higher all-cause mortality compared to those receiving an intra-annular BE valve at 5 years. A late catch up phenomenon of patients receiving the BE valve was observed beyond 3 years. Post-procedural moderate/severe PVR seems to play a crucial role in determining this finding. Comparative studies of new generation devices with longer follow-up are needed to evaluate the benefit of each specific TAV type.

Heart Disease and Stroke Statistics-2021 Update: A Report From the American Heart Association

BACKGROUND

The American Heart Association, in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The American Heart Association, through its Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update. The 2021 Statistical Update is the product of a full year's worth of effort by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. This year's edition includes data on the monitoring and benefits of cardiovascular health in the population, an enhanced focus on social determinants of health, adverse pregnancy outcomes, vascular contributions to brain health, the global burden of cardiovascular disease, and further evidence-based approaches to changing behaviors related to cardiovascular disease.

RESULTS

Each of the 27 chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policy makers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Safety of mapping in the sinus of valsalva region under intracardiac echocardiography guidance without angiography

Background

Radiofrequency ablation at the region of the sinus of Valsalva carries a risk to the ostia of the coronary arteries. Coronary angiography is usually utilized to document a safe distance for mapping and ablation.

Objective

To show that catheter ablation in the aortic root could be guided by phased-array intra cardiac echocardiography (ICE) and electro anatomic mapping without the need for coronary angiography.

Methods

We reviewed all patients referred to our lab that underwent mapping and/or ablation in the sinus of Valsalva region. Procedures were carried out by operators that are skilled in the use of ICE. The need for angiography was documented, also the rate of success along with the immediate and 30-day complications rate.

Results

Seventy patients (average age 48.7 ± 13.8 years; 64.3% males) were referred for ablation of ventricular and atrial arrhythmias. PVC constituted 95.7% of the cases. All patients underwent mapping and/or ablation at the sinus of Valsalva region without the need for coronary angiography to visualize the coronary ostia. Acute and effective ablation was achieved in 57 out of 70 (81.4%) patients partially effective ablation was achieved in 10 (14.3%) patients, and failure to ablate in the remaining 3 patients (4.3%). There was no occurrence of any adverse events, neither immediately or at day 30 after the procedure.

Conclusion

In the hands of experienced operators, mapping and radiofrequency ablation in the sinus of Valsalva can be safely and reliably performed using intracardiac echocardiography alone without the need for supplementary catheter coronary angiography.

The Effect of Accessory Pathway Location on Cardiac Function in Adult Patients with Wolff-Parkinson-White Syndrome

Introduction

The relationship between ventricular pre-excitation and left ventricular dysfunction has been described in the absence of sustained supraventricular tachycardia in a series of case reports. However, there have been no systematic studies about the effect of ventricular pre-excitation on cardiac function in adult patients with different accessory pathway locations.

Methods and Results

Patients were divided into four groups based on the type and location of their accessory pathway: septal, right free wall, left free wall, and concealed. N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels, electrocardiogram recordings, electrophysiological properties, and transthoracic echocardiographic data (septal-to-posterior wall motion delay (SPWMD) and interventricular mechanical delay (IVMD) indicating intraventricular and interventricular dyssynchrony) were compared before and after successful ablation. Before radiofrequency catheter ablation, left ventricular ejection fraction (LVEF) was significantly lower in patients with septal and right free wall accessory pathways. Within three months after radiofrequency catheter ablation, NT-proBNP levels decreased, left ventricular function improved, and intraventricular left ventricular dyssynchrony disappeared. There was a negative correlation between initial LVEF with initial QRS duration and initial SPWMD. Notably, SPWMD had a stronger correlation with LVEF than initial QRS duration.

Conclusions

Anterograde conduction with a septal or right free wall accessory pathway may cause left ventricular dyssynchrony and impair left ventricular function. Intraventricular left ventricular dyssynchrony seems to be responsible for the pathogenesis of left ventricular dysfunction. Radiofrequency catheter ablation results in decreased NT-proBNP levels, normalized QRS duration, mechanical resynchronization, and improved left ventricular function.

P2 Receptors in Cardiac Myocyte Pathophysiology and Mechanotransduction

ATP is a major energy source in the mammalian cells, but it is an extracellular chemical messenger acting on P2 purinergic receptors. A line of evidence has shown that ATP is released from many different types of cells including neurons, endothelial cells, and muscle cells. In this review, we described the distribution of P2 receptor subtypes in the cardiac cells and their physiological and pathological roles in the heart. So far, the effects of external application of ATP or its analogues, and those of UTP on cardiac contractility and rhythm have been reported. In addition, specific genetic alterations and pharmacological agonists and antagonists have been adopted to discover specific roles of P2 receptor subtypes including P2X4-, P2X7-, P2Y2- and P2Y6-receptors in cardiac cells under physiological and pathological conditions. Accumulated data suggest that P2X4 receptors may play a beneficial role in cardiac muscle function, and that P2Y2- and P2Y6-receptors can induce cardiac fibrosis. Recent evidence further demonstrates P2Y1 receptor and P2X4 receptor as important mechanical signaling molecules to alter membrane potential and Ca²⁺ signaling in atrial myocytes and their uneven expression profile between right and left atrium.

Electrophysiological Characteristics and Outcomes of Radiofrequency Catheter Ablation of Atrial Flutter in Children with or Without Congenital Heart Disease

There are scarce studies on radiofrequency catheter ablation (RFCA) of atrial flutter (AFL) in the pediatric population. This study therefore aimed to investigate the clinical features and RFCA of AFL in children with or without congenital heart disease. Data from 72 consecutive children (44 males; mean age, 6.1 ± 3.8 [0.9-15.0] years; and mean weight, 23.6 ± 13.9 [8.1-72.0] kg) undergoing RFCA for AFL from 2009 to 2019 were retrospectively reviewed. Thirty-three patients had normal cardiac structure and 39 had congenital heart disease (CHD) of whom 29 had undergone surgical repair and developed AFL at a mean of 3.1 ± 2.5 years later. Fifty-nine patients (84%) presented with persistent AFL. Five patients (7%) had cardiac dysfunction with LVEF of 30-48%, which normalized after ablation. Overall, acute success rate of ablation was 99% and recurrence rate was 18% at 0.5-10 years of follow-up. No procedure-related complications were identified. All 33 patients with normal cardiac structure had cavotricuspid isthmus (CTI)-dependent AFL. Among patients who had undergone corrective surgery for CHD, 15 (52%) had CTI-dependent AFL, 4 (14%) had surgical incisional scar reentrant AFL and the remaining 10 (34%) had both CTI-dependent and scar reentrant AFL. Success rate (100% vs. 97%, P = 1.0000) and recurrence rate (21% vs. 16%, P = 0.7008) were similar between patients with and without CHD. Overall, sick sinus syndrome (SSS) was found in 42% (30/72) of patients with AFL, with an incidence of 39% (13/33) among patients with normal cardiac structure and 59% (17/29) among those who underwent surgery for congenital defects. Permanent pacemakers (PM) were implanted in 53% (16/30) of patients with SSS after ablation. RFCA therefore appeared efficacious and safe for treatment of pediatric AFL. The mechanisms underlying AFL after corrective surgery for CHD are complex, including CTI-dependent macro-reentrant, scar reentrant, or a combination of both. SSS is not rare among pediatric AFL cases, with approximately half of patients needing PM implantation.

[Complete atrioventricular block revealed by an intermittent accessory pathway]

We report the case of syncope in a 75-year-old man with known coronary artery disease following complete atrioventricular block, which became symptomatic with the loss of anterograde conduction properties of his left postero-septal accessory pathway. A double chamber pacemaker implantation was decided. There is no indication for radiofrequency ablation in the absence of reentry tachycardia and intermittent conduction. Cardiac pacing offers him an electrophysiologically interesting excitation profile with a quasi-synchronous right and left ventricular activation.

Heart Disease and Stroke Statistics-2020 Update: A Report From the American Heart Association

BACKGROUND

The American Heart Association, in conjunction with the National Institutes of Health, annually reports on the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The American Heart Association, through its Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update. The 2020 Statistical Update is the product of a full year's worth of effort by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. This year's edition includes data on the monitoring and benefits of cardiovascular health in the population, metrics to assess and monitor healthy diets, an enhanced focus on social determinants of health, a focus on the global burden of cardiovascular disease, and further evidence-based approaches to changing behaviors, implementation strategies, and implications of the American Heart Association's 2020 Impact Goals.

RESULTS

Each of the 26 chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policy makers, media professionals, clinicians, healthcare administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Management of paroxysmal atrial flutter that occurred in an outpatient prior to dental surgery: a case report

Background

It is essential to accomplish the appropriate emergency care particularly in patients undergoing stressful dento-oral surgical procedures. Atrial flutter may be induced by sympathetic hypertonia due to excessive mental and physical stress. There is no report regarding dental care in patients with atrial flutter. Herein, we describe a rare case of the antiarrhythmic management in an outpatient who presented with an electrocardiographic finding of paroxysmal atrial flutter before the initiation of the dento-oral surgical procedure.

Case presentation

A 60-year-old male patient was scheduled for a dental extraction. He had a history of angina pectoris, diabetes mellitus, and paroxysmal atrial fibrillation with medication. The preoperative electrocardiogram (ECG) revealed left ventricular hypertrophy and ST-T segment abnormality. Immediately before the dental extraction, II-lead ECG revealed atrial flutter; however, he complained of few subjective symptoms, such as precordial discomfort or palpitation. Observing the vital signs, ECG findings, and the general condition of the patient, low dose diltiazem was immediately administered by continuous infusion in order to control the heart rate and prevent atrial flutter-induced supraventricular tachyarrhythmia. Special attention was paid to prevent any critical cardiovascular condition under a preparation of intravenous disopyramide and verapamil and a defibrillator. The intravenous administration of diltiazem progressively restored the sinus rhythm after converting atrial flutter into atrial fibrillation, resulting in the prevention of tachycardia, and then was found to be appropriate as a prophylactic therapy of tachyarrhythmia.

Conclusions

The present case suggests that it is possible to successfully manage some of such patients using our method during dento-oral surgery which is likely to be associated with mental and physical stress. Therefore, it is essential to accomplish an initial emergency care in parallel to the differential diagnosis of unforeseen serious medical conditions or paroxysmal arrhythmia such as atrial flutter.

Ablation of typical atrial flutter guided by the paced PR interval on the surface electrocardiogram: a proof of concept study

AIMS

We aimed to assess the novel concept of using the paced PR interval (PRI) on the surface electrocardiogram (ECG) to prove trans-isthmus block after cavotricuspid isthmus (CTI) ablation for typical atrial flutter (AFl).

METHODS AND RESULTS

Consecutive patients with AFl underwent linear radiofrequency ablation of the inferior CTI (6 o'clock). After AFl termination and/or presumed completion of the CTI line, CTI block was proven by atrial pacing by the ablation catheter medial (5 o'clock) and lateral to the line (7 and 9 o'clock). Corresponding PRIs were measured on the surface ECG. CTI block was assumed, if a sudden increase in the PRI was observed by moving the pacing site from 5 to 7 o'clock, and if the latter was longer than at 9 o'clock. Afterwards, bidirectional CTI block was confirmed by differential pacing. Thirty-one patients (mean age 67 ± 16 years, 81% male) underwent CTI ablation, and 18/31 (58%) were in AFl at the time of ablation (cycle length 249 ± 31 ms). Successful CTI block as defined by the PRI method was achieved in 31/31 (100%), and the mean PRIs during pacing at 5, 7, and 9 o'clock were 203 ± 56 ms, 329 ± 70 ms, and 296 ± 66 ms, respectively. Cavotricuspid isthmus block was confirmed in all patients (100%) by coronary sinus pacing with a reversal of the local activation sequence lateral to the isthmus line.

CONCLUSION

The method of PRI analysis on the surface ECG to guide CTI ablation is easy to apply and highly accurate in confirming CTI block. This simple technique enables the novel concept of CTI ablation and proof of block with a single catheter.

Feasibility and performance of catheter ablation with zero-fluoroscopy approach for regular supraventricular tachycardia in patients with structural and/or congenital heart disease

Patients with structural heart disease (SHD) are more difficult to ablate than those with a structurally healthy heart. The reason may be technical problems. We compared periprocedural data in unselected patients (including SHD group) recruited for zero-fluoroscopy catheter ablation (ZF-CA) of supraventricular arrhythmias (SVTs).Consecutive adult patients with atrioventricular nodal reentry tachycardia (AVNRT), accessory pathways (AP), atrial flutter (AFL), and atrial tachycardia (AT) were recruited. A 3-dimensional electroanatomical mapping system (Ensite Velocity, NavX, St Jude Medical, Lake Bluff, Illinois) was used to create electroanatomical maps and navigate catheters. Fluoroscopy was used on the decision of the first operator after 5 minutes of unresolved problems.Of the 1280 patients ablated with the intention to be treated with ZF approach, 174 (13.6%) patients with SHD (age: 58.2 ± 13.6; AVNRT: 23.9%; AP: 8.5%; AFL: 61.4%; and AT: 6.2%) were recruited. These patients were compared with the 1106 patients with nonstructural heart disease (NSHD) (age: 51.4 ± 16.4; AVNRT: 58.0%; AP: 17.6%; AFL: 20.7%; and AT: 3.7% P ≤ .001). Procedural time (49.9 ± 24.6 vs 49.1 ± 23.9 minutes, P = .55) and number of applications were similar between groups (P = 0.08). The rate of conversion from ZF-CA to fluoroscopy was slightly higher in SHD as compared to NSHD (13.2% vs 7.8%, P = .02) while the total time of fluoroscopy and radiation doses were comparable in the group of SHD and NSHD (P = .55; P = .48).ZF-CA is feasible and safe in majority of patients with SHD and should be incorporated into a standard approach for SHD; however, the procedure requires sufficient experience.

The Ionotropic P2X4 Receptor has Unique Properties in the Heart by Mediating the Negative Chronotropic Effect of ATP While Increasing the Ventricular Inotropy

Background: Mounting evidence indicate that reducing the sinoatrial node (SAN) activity may be a useful therapeutic strategy to control of heart failure. Purines, like ATP and its metabolite adenosine, consistently reduce the SAN spontaneous activity leading to negative cardiac chronotropy, with variable effects on the force of myocardial contraction (inotropy). Apart from adenosine A₁ receptors, the human SAN expresses high levels of ATP-sensitive ionotropic P2X4 receptors (P2X4R), yet their cardiac role is unexplored. Methods: Here, we investigated the activity of P2 purinoceptors on isolated spontaneously beating atria (chronotropy) and on 2 Hz-paced right ventricular (RV, inotropy) strips from Wistar rats. Results: ATP (pEC ₅₀ = 4.05) and its stable analogue ATPγS (pEC ₅₀ = 4.69) concentration-dependently reduced atrial chronotropy. Inhibition of ATP breakdown into adenosine by NTPDases with POM-1 failed to modify ATP-induced negative chronotropy. The effect of ATP on atrial rate was attenuated by a broad-spectrum P2 antagonist, PPADS, as well as by 5-BDBD, which selectively blocks the P2X4R subtype; however, no effect was observed upon blocking the A₁ receptor with DPCPX. The P2X4R positive allosteric modulator, ivermectin, increased the negative chronotropic response of ATP. Likewise, CTP, a P2X agonist that does not generate adenosine, replicated the P2X4R-mediated negative chronotropism of ATP. Inhibition of the Na⁺/Ca²⁺ exchanger (NCX) with KB-R7943 and ORM-10103, but not blockage of the HCN channel with ZD7288, mimicked the effect of the P2X4R blocker, 5-BDBD. In paced RV strips, ATP caused a mild negative inotropic effect, which magnitude was 2 to 3-fold increased by 5-BDBD and KB-R7943. Immunofluorescence confocal microscopy studies confirm that cardiomyocytes of the rat SAN and RV co-express P2X4R and NCX1 proteins. Conclusions: Data suggest that activation of ATP-sensitive P2X4R slows down heart rate by reducing the SAN activity while increasing the magnitude of ventricular contractions. The mechanism underlying the dual effect of ATP in the heart may involve inhibition of intracellular Ca²⁺-extrusion by bolstering NCX function in the reverse mode. Thus, targeting the P2X4R activation may create novel well-tolerated heart-rate lowering drugs with potential benefits in patients with deteriorated ventricular function.

Pharmacotherapeutic strategies for atrial fibrillation in pregnancy

Introduction: Atrial fibrillation (AF) is rare during pregnancy but its incidence is expected to rise in parallel to increasing age of women in pregnancy and fraction of pregnant women with structural heart disease. Areas covered: The authors provide a review of the contemporary evidence on diagnostic work-up and optimal pharmacotherapeutic management of AF in pregnancy. The authors have performed a systematic search for relevant articles using MEDLINE, the COCHRANE LIBRARY, and ClinicalTrials.gov. Expert opinion: New-onset AF during pregnancy is usually an indication of underlying heart disease and should lead to hospital admission. Patients should be evaluated by an experienced cardiologist or an electrophysiologist. Direct cardioversion is highly effective and safe in pregnant women and should be prioritized over pharmacologic cardioversion with intravenous ibutilide or flecainide. Amiodarone should be avoided if possible. Digoxin and beta-blockers are the rate-control pharmaceutic agents with the widest experience of use. Catheter ablation during pregnancy should be considered in selected cases of atrial flutter refractory to medication and only performed using fluoroless techniques, preferably during the second trimester. Vitamin K antagonists (VKAs) can be used after the first trimester, while low molecular weight heparin should be accompanied by periodic evaluation of anti-Xa factor. Non-VKA oral anticoagulants should be avoided because of limited experience in pregnancy.

Flecainide Toxicity Resulting in Pacemaker Latency and Intermittent Failure to Capture

Patient: Female, 91

Final Diagnosis: Flecainide toxicity

Symptoms: Bradycardia

Medication: Flecainide

Clinical Procedure: —

Specialty: Cardiology

A multicenter randomized controlled trial of a modified Valsalva maneuver for cardioversion of supraventricular tachycardias

CLINICAL QUESTION

Valsalva maneuver is a recognized treatment for supraventricular tachycardia, but in clinical setting it has a low chance to achieve successful cardioversion. Studies suggested that the postural modification of valsalva maneuver may improve the rate of cardioversion. We further modified the maneuver and conduct a multicenter randomized controlled trial to test its efficacy.

RESEARCH IN CONTEXT

Appelboam A, Reuben A, Mann C, et al. Postural modification of the standard Valsalva maneuver for emergency treatment for supraventricular tachycardias (REVERT): a randomized controlled trial. Lancet 2015; 386 (10005):1747-53 [1]. Allison Michaud, PhD, Eddy Lang. Leg lift Valsalva maneuver for treatment of supraventricular tachycardias. CJEM 2017; 19(3):235-237 [2].

OBJECTIVE

To verify the efficacy of the modified Valsalva maneuver in SVT in Chinese population and simplify the operation process further.

Efficacy of Nifekalant in Patients With Wolff-Parkinson-White Syndrome and Atrial Fibrillation: Electrophysiological and Clinical Findings

Background

The efficacy of nifekalant in preexcited atrial fibrillation (AF) has not been assessed.

Methods and Results

The study populations consisted of patients with sustained preexcited AF (n=51), paroxysmal supraventricular tachycardia (n=201), and persistent AF (n=87). Effects of intravenous infusion of nifekalant were assessed on electrophysiological and clinical parameters. Nifekalant prolonged the shortest preexcited R‐R, the average preexcited R‐R, and the average R‐R intervals from 290±35 to 333±44 ms, 353±49 to 443±64 ms, and 356±53 to 467±75 ms, respectively, in patients with preexcited AF (all P<0.001). Nifekalant also decreased the percentage of preexcited QRS complexes, heart rate, and increased systolic pressure (all P<0.001). Nifekalant terminated AF in 33 of 51 patients (65%). Similar effects were also observed in a subgroup of 12 patients with preexcited AF and impaired left ventricular function. In patients with paroxysmal supraventricular tachycardia, nifekalant significantly prolonged the effective refractory period, the block cycle length of the antegrade accessory pathway, and the atrial effective refractory period (all P<0.001). Nifekalant had no effect on the effective refractory period of the antegrade atrioventricular node. Finally, in patients with persistent AF without an accessory pathway, nifekalant did not significantly decrease the ventricular rate of AF. One patient developed Torsades de Pointes. No other adverse effects were observed.

Conclusions

Nifekalant prolongs the effective refractory period of the antegrade accessory pathway and atrium without blocking antegrade conduction through the atrioventricular node, leading to slowing and/or to termination of preexcited AF. Thus, nifekalant might be an effective and a relatively safe drug in patients with preexcited AF.

Late Outcomes of Surgical Ablation for Inappropriate Sinus Tachycardia

BACKGROUND

Inappropriate sinus tachycardia (IST) is a rare clinical disorder characterized by an elevated resting heart rate and an exaggerated rate response to exercise or autonomic stress. Pharmacologic therapy and catheter ablation are considered first-line treatments for IST but can yield suboptimal relief of symptoms. The results of surgical ablation at our center were reviewed for patients with refractory IST.

METHODS

Between 1987 and 2018, 18 patients underwent surgical sinoatrial (SA) node isolation for treatment-refractory IST. All 18 patients had previously failed pharmacologic therapy, and 15 patients had failed catheter ablation of the SA node.

RESULTS

Ten patients underwent a median sternotomy, and 8 patients underwent a minimally invasive right thoracotomy. The SA node was isolated with the use of surgical incisions, cryoablation, or bipolar radiofrequency ablations. Sinus tachycardia was eliminated in 100% of patients in the immediate postoperative period. Long-term follow-up data were available for 17 patients, with a mean follow-up of 11.4 ± 7.9 years. At last follow-up, 100% of patients were free from recurrent symptomatic IST. More than 80% of patients were completely asymptomatic, whereas 3 patients reported occasional palpitations. Four patients were on β-blockers, and 5 patients required subsequent pacemaker implantation. All 8 patients who underwent minimally invasive isolation were in normal sinus rhythm at last follow-up, and only 1 patient complained of palpitations.

CONCLUSIONS

Surgical isolation of the SA node is a feasible treatment for IST refractory to pharmacologic therapy and catheter ablation. A minimally invasive surgical approach offers a less morbid alternative to traditional median sternotomy.

Atrioventricular node reentrant tachycardia: Remote magnetic navigation ablation versus manual ablation - impact on operator fluoroscopy time

INTRODUCTION AND AIMS

Remote magnetic navigation systems have demonstrated benefits in the ablation of difficult substrates. Their role in the ablation of atrioventricular nodal reentrant tachycardia (AVNRT), however, has only been studied in small patient series. The aim of this study was to compare the results of AVNRT ablation using magnetic navigation, in a center where every procedure is performed with this system, with manual ablation.

METHODS

We selected 139 consecutive patients undergoing AVNRT ablation with magnetic navigation by a single operator between January 2009 and June 2016 and compared them to a group of 101 consecutive patients undergoing manual ablation in the same period by the same operator in another hospital. The methodology was the same in both groups. Success rates, complications, procedure time, radiofrequency time, total and operator fluoroscopy time, and recurrence rates were compared.

RESULTS

There were no differences in success and complication rates. Procedure and total fluoroscopy times were not significantly different, but operator fluoroscopy time was significantly shorter with the magnetic navigation system (2.4±1.5 min vs. 7.2±4 min; p<0.001). The recurrence rate was higher in the manual group, although without statistical significance.

CONCLUSIONS

The ablation of AVNRT with magnetic navigation is feasible using the same methodology as for manual ablation. Success and complication rates were similar. Operator fluoroscopy time was significantly less with the magnetic navigation system.

Revelation of early repolarization by eliminating accessory pathway in manifest Wolff-Parkinson-White syndrome: A case report

A 23-year-old male with manifest Wolff-Parkinson-White syndrome presented with a first occurrence of ventricular fibrillation (VF). Initially, we anticipated the occurrence of atrial fibrillation, causing rapid antegrade conduction over the accessory pathway and, thus, resulting in hemodynamic deterioration. Electrophysiological study revealed that the atrioventricular accessory pathway was located at the mid-septum. After eliminating the pathway, a J-point elevation was revealed in the inferior and lateral leads. In addition, program ventricular stimulation induced VF, and the administration of isoproterenol suppressed VF. In our case, VF occurrence can be attributed to early repolarization syndrome and ventricular preexcitation-modified J-point elevation.

Management of asymptomatic arrhythmias: a European Heart Rhythm Association (EHRA) consensus document, endorsed by the Heart Failure Association (HFA), Heart Rhythm Society (HRS), Asia Pacific Heart Rhythm Society (APHRS), Cardiac Arrhythmia Society of Southern Africa (CASSA), and Latin America Heart Rhythm Society (LAHRS)

Asymptomatic arrhythmias are frequently encountered in clinical practice. Although studies specifically dedicated to these asymptomatic arrhythmias are lacking, many arrhythmias still require proper diagnostic and prognostic evaluation and treatment to avoid severe consequences, such as stroke or systemic emboli, heart failure, or sudden cardiac death. The present document reviews the evidence, where available, and attempts to reach a consensus, where evidence is insufficient or conflicting.