Management of acute supraventricular tachycardia in children

QUESTION

Recently, a 3-year-old patient in my practice urgently needed to go to the emergency department. The patient was found to have supraventricular tachycardia (SVT) and needed immediate treatment with adenosine. What evidence is currently available for management of SVT in children?

ANSWER

Supraventricular tachycardia is a common cardiac condition in the pediatric population that manifests as a narrow QRS complex tachycardia on electrocardiography. Symptoms may range from palpitations, poor feeding, and irritability to more substantial hemodynamic instability. Patients who are hemodynamically stable can benefit from interventions such as vagal maneuvers, which can be done in the office. Such maneuvers include the Valsalva maneuver, stimulation of the diving reflex (for infants), and unilateral carotid sinus massage. Other children may need pharmacologic therapies to restore normal heart rhythm, which usually consists of a rapid intravenous injection of adenosine under monitoring. For patients who are hemodynamically unstable, emergency cardioversion may be needed.

An unmet need: arrhythmia detection by implantable loop recorder in the systemic right ventricle

AIMS

Patients with systemic right ventricles are at high risk of sudden cardiac death. Arrhythmia is a significant risk factor. Routine Holter monitoring is opportunistic with poor adherence. The aim of this study was to determine if continuous rhythm monitoring with an implantable loop recorder (ILR) could allow early detection of clinically important arrhythmias.

METHODS AND RESULTS

Implantable loop recorder implantation was offered to patients with atrial switch repair for transposition of the great arteries. Recordings were made with symptoms or, automatically for pauses, significant bradycardia or tachycardia and reviewed by the multi-disciplinary team. Twenty-four out of 36 eligible patients underwent ILR implantation with no complication. Forty-two per cent had preserved ventricular function, 75% were NYHA functional class I, 88% had low sudden cardiac death risk, 33% had previous intra-atrial re-entrant tachycardia (IART), and none had known conduction disease. Eighteen out of 24 (75%) patients made 52 recordings (52% automated) over 39.5 months (1.6-72.5). Thirty-two out of 52 (62%) recordings in 15/24 (63%) of the cohort were clinically significant and included sinus node disease (two patients), atrioventricular block (two patients), IART (seven patients), and IART with sinus node disease or atrioventricular block (four patients). Implantable loop recorder recordings prompted medication change in 11 patients [beta-blockers (n = 9), anti-coagulation (n = 5), and stopping anti-coagulation (n = 1)] and device therapy recommendation in seven patients [five pacemakers (three: atrioventricular block) and two defibrillators]. Two patients declined intervention; one suffered an arrhythmic death. Intra-atrial re-entrant tachycardia and clinically relevant conduction disease were detected in patients irrespective of sudden cardiac death risk.

CONCLUSION

Continuous monitoring with an ILR in patients with systemic right ventricle following atrial switch detects clinically relevant arrhythmias that impact decision-making. In this cohort, clinically relevant arrhythmias did not correlate with sudden cardiac death risk.

Supraventricular Tachycardia in the Setting of Neonatal COVID-19 Infection: A Case Report

BACKGROUND

COVID-19 infection, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), may present with a wide range of clinical presentations and a variety of symptoms in neonates. The cardiovascular manifestations that have been described in the setting of COVID-19 infection in neonates are tachycardia and hypotension, but information regarding cardiac arrhythmias is scarce, while the effect of SARS-CoV-2 on myocardial function is still not well established.

CLINICAL FINDINGS

We present a case of a neonate admitted with fever and nasal congestion.

PRIMARY DIAGNOSIS

The neonate was tested positive for SARS-CoV-2. Supraventricular tachycardia (SVT) was diagnosed during his hospitalization in the neonatal intensive care unit.

INTERVENTIONS

The neonate was under treatment with intravenous fluid repletion, intravenous broad-spectrum antibiotics, and continuous hemodynamic monitoring. SVT resolved spontaneously, while the team was preparing application of further supportive measures with a bag of ice on the infant's face.

OUTCOMES

The neonate was discharged in good condition on day 14 post-admission, with no further recurrence of SVT. Follow-up visits were scheduled with the cardiologist.

PRACTICE RECOMMENDATIONS

SVT in full-term or premature neonates can be a clinical manifestation of COVID-19 infection. Both neonatologists and neonatal nurse practitioners should be prepared to deal with cardiological manifestations of COVID-19 infection in neonates.

Pathophysiology and treatment of adults with arrhythmias in the emergency department, part 1: Atrial arrhythmias

PURPOSE

This article, the first in a 2-part review, aims to reinforce current literature on the pathophysiology of cardiac arrhythmias and various evidence-based treatment approaches and clinical considerations in the acute care setting. Part 1 of this series focuses on atrial arrhythmias.

SUMMARY

Arrhythmias are prevalent throughout the world and a common presenting condition in the emergency department (ED) setting. Atrial fibrillation (AF) is the most common arrhythmia worldwide and expected to increase in prevalence. Treatment approaches have evolved over time with advances in catheter-directed ablation. Based on historic trials, heart rate control has been the long-standing accepted outpatient treatment modality for AF, but the use of antiarrhythmics is often still indicated for AF in the acute setting, and ED pharmacists should be prepared and poised to help in AF management. Other atrial arrhythmias include atrial flutter (AFL), atrioventricular nodal reentry tachycardia (AVNRT), and atrioventricular reentrant tachycardia (AVRT), which warrant distinction due to their unique pathophysiology and because each requires a different approach to utilization of antiarrhythmics. Atrial arrhythmias are typically associated with greater hemodynamic stability than ventricular arrhythmias but still require nuanced management according to patient subset and risk factors. Since antiarrhythmics can also be proarrhythmic, they may destabilize the patient due to adverse effects, many of which are the focus of black-box label warnings that can be overreaching and limit treatment options. Electrical cardioversion for atrial arrhythmias is generally successful and, depending on the setting and/or hemodynamics, often indicated.

CONCLUSION

Atrial arrhythmias arise from a variety of mechanisms, and appropriate treatment depends on various factors. A firm understanding of physiological and pharmacological concepts serves as a foundation for exploring evidence supporting agents, indications, and adverse effects in order to provide appropriate care for patients.

Evaluation of the prehospital use of a Valsalva assist device in the emergency treatment of supraventricular tachycardia (EVADE SVT): study protocol for a stepped wedge cluster randomised controlled trial

INTRODUCTION

Patients with episodes of supraventricular tachycardia (SVT), a common heart arrhythmia, are often attended by ambulance services. International guidelines advocate treatment with the Valsalva manoeuvre (VM), but this simple physical treatment has a low success rate, with most patients requiring conveyance to hospital. The Valsalva Assist Device (VAD) is a simple device that might help practitioners and patients perform a more effective VM and reduce the need for patients to be taken to hospital.

METHODS AND ANALYSIS

This stepped wedge cluster randomised controlled trial, conducted within a UK ambulance service, compares the current standard VM with a VAD-delivered VM in stable adult patients presenting to the ambulance service with SVT. The primary outcome is conveyance to hospital; secondary outcomes measures include cardioversion rates, duration of ambulance care and number of subsequent episodes of SVT requiring ambulance service care. We plan to recruit approximately 800 patients, to have 90% power to detect an absolute reduction in conveyance rate of 10% (from 90% to 80%) between the standard VM (control) and VAD-delivered VM (intervention). Such a reduction in conveyance would benefit patients, the ambulance service and receiving emergency departments. It is estimated potential savings would pay for devices for the entire ambulance trust within 7 months.

ETHICS AND DISSEMINATION

The study has been approved by the Oxford Research Ethics Committee (reference 22/SC/0032). Dissemination will be through peer-reviewed journal publication, presentation at national and international conferences and by the Arrhythmia Alliance, a patient support charity.

TRIAL REGISTRATION NUMBER

ISRCTN16145266.

Common Types of Supraventricular Tachycardia: Diagnosis and Management

Supraventricular tachycardia (SVT) is an abnormal rapid cardiac rhythm that involves atrial or atrioventricular node tissue from the His bundle or above. Paroxysmal SVT, a subset of supraventricular dysrhythmias, has three common types: atrioventricular nodal reentrant tachycardia, atrioventricular reentrant tachycardia, and atrial tachycardia. Presenting symptoms may include altered consciousness, chest pressure or discomfort, dyspnea, fatigue, lightheadedness, or palpitations. Diagnostic evaluation may be performed in the outpatient setting and includes a comprehensive history and physical examination, electrocardiography, and laboratory workup. Extended cardiac monitoring with a Holter monitor or event recorder may be needed to confirm the diagnosis. Acute management of paroxysmal SVT is similar across the various types and is best completed in the emergency department or hospital setting. In patients who are hemodynamically unstable, synchronized cardioversion is first-line management. In those who are hemodynamically stable, vagal maneuvers are first-line management, followed by stepwise medication management if ineffective. Beta blockers and/or calcium channel blockers may be used acutely or for long-term suppressive therapy. When evaluating patients for paroxysmal SVTs, clinicians should have a low threshold for referral to a cardiologist for electrophysiologic study and appropriate intervention such as ablation. Clinicians should use a patient-centered approach when formulating a long-term management plan for atrioventricular nodal reentrant tachycardia. Catheter ablation has a high success rate and is recommended as the first-line method for long-term management of recurrent, symptomatic paroxysmal SVT, including Wolff-Parkinson-White syndrome.

[Therapeutic effect of a nasal swab: an accidental vagal manoeuvre in a patient with supraventricular tachycardia]

BACKGROUND

The case gives the reader a valuable insight in pathophysiology and treatment in atrioventricular nodal re-entry tachycardia (AVNRT) and vagal manoeuvres available to treat this phenomenon.

CASE DESCRIPTION

A 85-year-old woman with a medical history of heart failure and aortic valve stenosis presents herself on the Emergency Department with cardiac shock and cardiac asthma. The ECG showed an AVNRT with 170 beats per minute (bpm) and a left bundle branch block (LBBB). After nasal swab for COVID-19 cardiac rhythm converted to a sinus or atrial tachycardia with 116bpm. The patients circulatory status improved and could then be treated with diuretics. Nasal swabs can lead to stimulation of the glossopharyngeal nerve with increase parasympathetic activity leading to a remission of atrioventricular re-entry tachycardia.

CONCLUSION

Nasal swabs can lead to increased parasympathetic activity in the atrioventricular node and cause conversion of supraventricular tachycardia to sinus rhythm.

The use of vagal manoeuvres in narrow complex tachyarrhythmias in primary care

Supraventricular tachydysrhythmias (SVTs) are a common presenting complaint, with a national prevalence of 3/1000 persons. While most commonly stable, prolonged paroxysms can deteriorate into haemodynamically unstable subtypes or ventricular dysrhythmias. Early recognition with appropriate management is critical to reducing the morbidity associated with this condition. The American Heart Association holds that vagal manoeuvres are a first-line therapy in the management algorithm of stable SVTs. However, they state that no clear recommendations can be made around which manoeuvre to use, highlighting that future research should examine the efficacy and safety profiles of the various manoeuvres. In the South African primary care setting, clinicians must be at the forefront of pragmatic management strategies in the face of resource limitations, such as the unavailability of adenosine – a second-line therapy when vagal manoeuvres fail. In this article, we begin with a case study and review the literature around vagal manoeuvres.

Arrhythmic manifestation in β-thalassemia cardiomyopathy: a complex management

A young male with β-thalassemia major was implanted with a single-chamber Implantable cardioverter-defibrillator (ICD) for a cardiac arrest due to ventricular fibrillation. He received multiple inappropriate shocks due to atrioventricular nodal re-entrant tachycardia (AVNRT) treated with radiofrequency catheter ablation and then to high-rate atrial tachycardia refractory to amiodarone and not inducible during electrophysiological study. He refused empirical pulmonary vein isolation. Upgrading to biventricular ICD and performing atrioventricular node ablation avoided further inappropriate shocks.

Effectiveness of the modified Valsalva manoeuvre in adults with supraventricular tachycardia: a systematic review and meta-analysis

BACKGROUND AND IMPORTANCE

Cardiac arrhythmia, specifically paroxysmal supraventricular tachycardia (SVT), accounts for a substantial proportion of emergency medical services resources utilisation. Reconversion requires increasing the atrioventricular node's refractoriness, which can be achieved by vagal manoeuvres, pharmacological agents or electrical cardioversion. There are multiple variants of vagal manoeuvres, including the Valsalva manoeuvre (VM). While the effectiveness of the standard VM has already been systematically reviewed, there has been no such analysis for the modified VM.

OBJECTIVES

Compare the effectiveness of the modified VM versus the standard VM in restoring the normal sinus rhythm in adult patients with supraventricular tachycardia.

DESIGN

Systematic review with meta-analysis of published randomised controlled trials.

OUTCOME MEASURES

The primary outcome was the reconversion to a sinus rhythm. Secondary outcomes included: medication use, adverse events, length of stay in the emergency department and hospital admission.

MAIN RESULTS

Five randomised controlled trials were included, with a combined total of 1181 participants. The meta-analysis demonstrated a significantly higher success rate for reconversion to sinus rhythm when using the modified VM compared to the standard VM in patients with an SVT (odds ratio = 4.36; 95% confidence interval, 3.30-5.76; P < 0.001). More adverse events were reported in the modified VM group, although this difference is NS (risk ratio = 1.48; 95% confidence interval, 0.91-2.42; P = 0.11). The available evidence suggests that medication use was lower in the modified VM group than the standard VM group. However, medication use could not be generalised across the different studies. None of the included studies showed a significant difference in length of stay in the emergency department. Only one study reported on hospital admission, with no significant difference between the two groups.

CONCLUSIONS

The available evidence is highly suggestive to support the use of the modified VM compared to the standard VM in the treatment of adult patients with SVT. Meta-analysis showed a higher success rate, required less medication use, and resulted in an equal number of adverse events. However, these results cannot be regarded as definitive in the absence of higher-quality studies.

Essentials of Paroxysmal Supraventricular Tachycardia for the Pediatrician

Paroxysmal supraventricular tachycardia (SVT) is the most common clinical arrhythmia in young patients. With an estimated prevalence of roughly 1 in 500 children, a pediatrician may knowingly or unknowingly see several patients who are affected each year. SVT symptoms can sometimes be vague or conflated with common pediatric complaints. Different forms of SVT are predominant at different ages, sometimes complicating timely recognition and referral. Differing pathophysiology and age distribution impact risk of complications such as heart failure, or rarely, sudden death. Treatment choices continue to evolve as new medications, monitoring devices, and ablation technologies continue to mature. This review focuses on the most common types of paroxysmal SVT: atrioventricular nodal reentrant tachycardia, atrioventricular reciprocating tachycardia, and Wolff-Parkinson White syndrome. Atrial arrhythmia mechanisms are also briefly outlined. It is meant to provide practical guidelines for the diagnosis and management of patients with SVT from infancy through adolescence. [Pediatr Ann. 2021;50(3):e113-e120.].

The prevalence and clinical outcome of supraventricular tachycardia in different etiologies of pulmonary hypertension

Purpose

Patients with pulmonary hypertension (PH) frequently suffer from supraventricular tachycardias (SVT). The main purpose of our study was to identify the cumulative incidence of SVT in patients with different etiologies of PH. The secondary objective was to analyse the clinical impact of SVT.

Methods

We retrospectively studied the prevalence of SVT and the clinical outcome in 755 patients (41% males; 60 ± 15 years; mean follow-up 3.8 ± 2.8 years) with PH of different etiologies. The prevalence of SVT was analysed separately in isolated pre-capillary PH (Ipc-PH) and in patients with combined post- and pre-capillary PH (Cpc-PH).

Results

The prevalence of SVT in the Ipc-PH group (n = 641) was 25% (n = 162). The most prevalent arrhythmias were atrial fibrillation followed by a typical atrial flutter (17% and 4.4% of all Icp-PH patients). An excessive prevalence of SVT was found in patients with pulmonary arterial hypertension associated with congenital heart disease (35%, p = 0.01). Out of the overall study population, Cpc-PH was present in 114 (15%) patients. Patients with Cpc-PH manifested a higher prevalence of SVT than subjects with Ipc-PH (58; 51% vs. 162; 25%; p <0.0001) and were more likely to have persistent or permanent atrial fibrillation (38; 29% vs. 61; 10%; p <0.0001). Parameters significantly associated with mortality in a multivariate analysis included age, male gender, functional exercise capacity and right atrial diameter (p < 0.05). Neither diagnosis of SVT nor type of arrhythmia predicted mortality.

Conclusions

The study detected a significant prevalence of SVT in the population of PH of different origins. Different spectrum and prevalence of arrhythmia might be expected in different etiologies of PH. Patients with an elevated post-capillary pressure showed a higher arrhythmia prevalence, predominantly due to an excessive number of atrial fibrillations. The diagnosis of SVT was not associated with mortality.

The reverse vagal manoeuvre: A new tool for treatment of supraventricular tachycardia?

Supraventricular tachycardia is a common cardiac arrhytmia with recurrent episodes. The rapid resolution of supraventricular tachycardia remains a challenge. Vagal manoeuvres are simple and non-invasive but yield positive results in less than half the cases. Currently, the modified Valsalva manoeuvre appears to be the most effective technique. We have tested the effectiveness of the reverse Valsalva manoeuvre without swallowing as new vagal manoeuvre for the treatment of supraventricular tachycardia. This new technique is easy to perform and can be carried out alone by the patient. We report in this series 11 cases of supraventricular tachycardia, 10 of which were effectively reduced after the completion of the reverse Valsava manoeuvre. The very encouraging results of this series of cases will have to be quickly evaluated by a randomised controlled trial. This new technique, which is simple to learn and carry out, could be easily taught throughout the world, including in regions with few health-care resources.

Neonatal supraventricular tachycardia and necrotizing enterocolitis: case report and literature review

BACKGROUND

Necrotizing enterocolitis (NEC) and supraventricular tachycardia (SVT) are serious emergencies in the neonatal period. Although these conditions are recognized as distinct pathologies, literature reports suggest that recurrent episodes of SVT may predispose patients to NEC via disturbances in mesenteric blood flow and a decrease in tissue perfusion.

CASE PRESENTATION

We present a case of a preterm infant affected by recurrent episodes of SVT who developed the initial stage of NEC on the 17th day of life. Moreover, a detailed description of all the cases described in the literature is reported.

MATERIALS AND METHODS

An integrative review of the updated literature in the Medline database and PubMed and scientific books and articles was conducted. The research from October 2019 to December 2019 was searched for with MeSH and free terms (necrotizing enterocolitis, supraventricular tachycardia) and was linked by Boolean operators.

CONCLUSIONS

SVT can be considered a risk factor for the development of NEC. Therefore, clinicians should have a high level of suspicion for NEC in infants affected by SVT. This article is the first structured literature review analysing the association between SVT and NEC.

Supraventricular tachydysrhythmias in the emergency department

Diagnosing and treating supraventricular tachycardias is routine in emergency medicine, and new strategies can improve efficiency and outcomes. This review provides an overview of supraventricular tachycardias, their pathophysiology, differential diagnosis, and electrocardiographic features. Clinical evidence guiding contemporary practice is determined largely by multiple observational studies, with few randomized controlled trials. Current prehospital and emergency department management strategies beyond the use of adenosine and calcium channel blockers are addressed. Diagnostic and therapeutic recommendations are provided, based on the best available evidence.

Transesophageal Overdrive Pacing in a Patient with Atrial Tachycardia and beta -Thalassemia Major. A Challenging Simplicity

Introduction:

Transesophageal overdrive pacing is an accepted method for the diagnosis and treatment of supraventricular tachycardias, although is not used frequently in clinical practice.

Case report:

A 47 years old woman is reported with a medical history of β -Thalassemia Major admitted to our hospital with atrial tachycardia of recent onset and successfully converted using a transesophageal overdrive atrial pacing.

Conclusion:

Transesophageal overdrive atrial pacing is a low cost, simple and safe procedure that can be performed at the bedside, especially in patients, as those with β -Thalassemia Major, whose health status makes difficult the usage of medicines that could possibly aggravate their general health status.

Supraventricular tachycardia: An overview of diagnosis and management

Supraventricular tachycardia (SVT) is a common cause of hospital admissions and can cause significant patient discomfort and distress. The most common SVTs include atrioventricular nodal re-entrant tachycardia, atrioventricular re-entrant tachycardia and atrial tachycardia. In many cases, the underlying mechanism can be deduced from electrocardiography during tachycardia, comparing it with sinus rhythm, and assessing the onset and offset of tachycardia. Recent European Society of Cardiology guidelines continue to advocate the use of vagal manoeuvres and adenosine as first-line therapies in the acute diagnosis and management of SVT. Alternative therapies include the use of beta-blockers and calcium channel blockers. All patients treated for SVT should be referred for a heart rhythm specialist opinion. Long-term treatment is dependent on several factors including frequency of symptoms, risk stratification, and patient preference. Management can range from conservative, if symptoms are rare and the patient is low risk, to catheter ablation which is curative in the majority of patients.

La tachycardie atriale mal tolérée du nouveau-né: à propos d’un cas

Les troubles du rythme cardiaque mal tolérés du nouveau-né sont une véritable urgence nécessitant une prise en charge rapide et adéquate. Nous rapportons le cas d'un nouveau-né de 15 jours présentant une tachycardie atriale en défaillance cardiaque aiguë ayant nécessité une cardioversion électrique.

Supraventricular Tachycardia

The term paroxysmal supraventricular tachycardia encompasses a heterogeneous group of arrhythmias with different electrophysiologic characteristics. Knowledge of the mechanism of each supraventricular tachycardia is important in determining management in the office, at the bedside, and in the electrophysiology laboratory. Paroxysmal supraventricular tachycardias have an abrupt onset and offset, typically initiating and terminating with premature atrial ectopic beats. In the acute setting, both vagal maneuvers and pharmacologic therapy can be effective in arrhythmia termination. Catheter ablation has revolutionized therapy for many supraventricular tachycardias, and newer techniques have significantly improved ablation efficacy and decreased periprocedural complications and procedure times.

Inappropriately Firing Defibrillator: A Simulation Case for Emergency Medicine Residents

INTRODUCTION

Emergency physicians must be able to manage inappropriately firing defibrillators. Many physicians may not experience this high-risk, low-frequency patient presentation during residency. We created this simulation to increase residents' knowledge of basic defibrillator function and confidence in managing patients with malfunctioning defibrillators.

METHODS

Sixteen emergency medicine residents of all levels of training participated in this curriculum. The educational experience began with a lecture. Residents then managed the simulated patient encounter in groups of four. The patient was a 63-year-old male presenting after feeling his defibrillator fire. He was found to have a supraventricular tachycardia with an inappropriately firing defibrillator. Learners needed to recognize the inappropriately firing defibrillator, inactivate it with a magnet, and treat the arrhythmia. Implementation of this scenario required audiovisual equipment and a simulation room equipped with high-fidelity simulator, patient monitor, code cart, defibrillator, and pacemaker magnet. Learners completed pre- and postcourse surveys to assess changes in baseline knowledge of defibrillator function and self-reported confidence in managing these complicated patients.

RESULTS

After participating in this educational intervention, residents improved their performance on a 10-question quiz from a class mean of 60% to 84% (p < .001). Residents also exhibited an increase in self-reported confidence in managing patients with inappropriately firing defibrillators (p < .001) and in knowing when to place a magnet over a patient's defibrillator (p < .001).

DISCUSSION

Residents demonstrated increased knowledge of defibrillator function as well as increased confidence in managing patients with malfunctioning defibrillators after participating in this simulation experience.

Cardiac electrophysiologic procedures - A ten years' experience at National Institute of Cardiovascular Diseases, Karachi

OBJECTIVE

To review 10 years of clinical practice of cardiac electrophysiology study and radiofrequency catheter ablation in the treatment of supraventricular tachycardia.

METHODS

The retrospective chart review was conducted at the National Institute of Cardiovascular Diseases, Karachi, and comprised records of all patients who underwent electrophysiological study and / or radiofrequency catheter ablation from January2007 to December 2016. SPSS 21 was used for data analysis.

RESULTS

Of the 627 patients, 335(53.4%) were females. The overall mean age was 40.99}13.59 years. The major indication for procedure was supraventricular tachycardia 376(59.97%). Final electrophysiological study diagnosis was typical slow fast atrioventricular nodal re-entrant tachycardia in 303(48.3%) patients. The overall success rate was 472(75.3%). Procedure-related complications were reported in 25(4%) patients, and there was 1(0.15%) mortality.

CONCLUSIONS

Cardiac electrophysiology studies and radiofrequency catheter ablation were found to be an effective and safe method for diagnosis and treatment of supraventricular tachycardia.

Supraventricular Arrhythmias: Clinical Framework and Common Scenarios for the Internist

Supraventricular arrhythmias can cause uncomfortable symptoms for patients. Often, the first point of contact is in the primary care setting, and thus, it is imperative for the general internist to have a clinical framework in place to recognize this cluster of cardiac arrhythmias, be familiar with immediate and long-term management of supraventricular tachycardias, and understand when cardiac electrophysiologic consultation is necessary. The electrocardiographic characteristics can have subtle but important clues to the diagnosis and initial management. An understanding of the mechanisms of these arrhythmias is essential to provide proper therapy to the patient. In addition, there are common practice strategies that should be emphasized to avoid common misperceptions that could pose risk to the patient. In this review, we provide a framework to more easily recognize and classify these arrhythmias. We also illustrate the mechanism for these arrhythmias to provide an understanding of the interventions generally used.

Pacemaker implantation for treating migraine-like headache secondary to cardiac arrhythmia: A case report

RATIONALE

Co-occurrence of headache and arrhythmia is not rare. However, their causal relationship remains unclear. Here, we described a case of migraine-like headache relieving with pacemaker implantation. Our case study indicates that arrhythmia is causal for migraine-like headache, which, to our knowledge, has never been reported.

PATIENT CONCERNS

A 63-year-old woman patient suffered from paroxysmal headache with a visual aura presenting like migraine for 2 years. No ophthalmic or neurological disorder was found, but cardiac examination detected bradycardia, which was confirmed by 24-hour dynamic electrocardiogram (DCG) revealing sinus bradycardia mixed with ventricular premature beats and supraventricular tachycardia. Transcranial doppler (TCD) detected an equal echo flat plaque on the anterolateral wall of the common carotid artery (CA) bifurcation.

DIAGNOSIS

Migraine-like headaches secondary to arrhythmia.

INTERVENTIONS

The patient underwent pacemaker implantation.

OUTCOMES

Both visual aura and headache were resolved following pacemaker implantation.

LESSONS

To the best of the authors' knowledge, we are the first to report migraine-like headache as a secondary symptom of arrhythmia. Arrhythmia may aggravate insufficient blood supply to the brain due to CA lesion and induce a migraine-like headache. This case study indicated that pacemaker implantation could be a fundamental treatment for migraine-like headaches caused by cardiac arrhythmia.

In-Flight Management of a Supraventricular Tachycardia Using Telemedicine

BACKGROUND

Supraventricular tachycardia (SVT) is a common presenting arrhythmia in the general population. Cases of SVT presenting during commercial air travel are always challenging as they might be confused with other conditions requiring different treatment strategies. We present a case of an in-flight SVT that was successfully managed using telemedicine support.

CASE REPORT

A 33-yr-old woman developed chest pain and dizziness while on an international commercial flight. Vital signs obtained on an on-board telemedicine device recorded an initial heart rate and blood pressure of 220 bpm and 128/78 mmHg, respectively. An electrocardiogram (ECG) was also obtained and transmitted to the ground-based medical support (GBMS) center where an SVT was diagnosed. Vagal maneuvers were recommended which resulted in a return to sinus rhythm and stabilization of the patient.

DISCUSSION

In parallel to the global increase in commercial air travel, it is expected that the incidence of in-flight arrhythmias will also increase, including SVTs. Vagal maneuvers are a safe, first-line option. While treating patients with a symptomatic tachyarrhythmia it is essential to diagnose the underlying arrhythmia, especially when initial maneuvers fail. Telemedicine, with transmission of vital signs and ECGs to GBMS centers, can enable diagnosis and guide management of in-flight SVTs, distinguishing them from other forms of cardiac arrhythmia. Undifferentiated chest pain and dizziness are common causes for flight diversions and, as such, could potentially be prevented in some instances by using telemedicine.Voerman JJ, Hoffe ME, Surka S, Alves PM. In-flight management of a supraventricular tachycardia using telemedicine. Aerosp Med Hum Perform. 2018; 89(7):657-660.

Optogenetic termination of atrial fibrillation in mice

Aims

The primary goal in the treatment of symptomatic atrial fibrillation/flutter (AF) is to restore sinus rhythm by cardioversion. Electrical shocks are highly effective, but have to be applied under analgo-sedation and can further harm the heart. In order to develop a novel pain-free and less harmful approach, we explored herein the optogenetic cardioversion by light-induced depolarization.

Methods and results

Hearts from mice expressing Channelrhodopsin-2 (ChR2) and the AF-promoting loss-of-function Connexin 40 Ala96Ser mutation were explanted and perfused with low K+ Tyrode's solution and an atrial KATP-channel activator. This new protocol shortened atrial refractoriness as well as slowed atrial conduction and thereby enabled the induction of sustained AF. AF episodes could be terminated by epicardial illumination of the atria with focussed blue light (470 nm, 0.4 mW/mm2) with an efficacy of ∼97% (n = 17 hearts). In > 80% of cases, light directly terminated the AF episode with onset of illumination. Because similar illumination intensity was able to locally inhibit atrial activity, we propose that a light-induced block of electrical activity is responsible for reliable AF termination. The success rate was strongly depending on the illuminated area, applied light intensity and duration of illumination. Importantly, we were also able to demonstrate optogenetic termination of AF in vivo, using epicardial illumination through the open chest (n = 3 hearts). To point towards a translational potential, we systemically injected an adeno-associated virus to express ChR2 in wild type hearts. After 6-8 months, we found robust ChR2 expression in the atria, enabling light-mediated AF termination in six of seven mice tested.

Conclusion

We provide the first evidence for optogenetic termination of atrial tachyarrhythmia in intact hearts from transgenic as well as wild type mice ex and in vivo. Thus, this report could lay the foundation for the development of implantable devices for pain-free termination of AF.

INFLUENCE OF CATHETER ABLATION OF PAROXYSMAL SUPRAVENTRICULAR TACHYCARDIA ON PATIENTS' ANXIETY

The aim of the study was to investigate the influence of catheter ablation of paroxysmal supraventricular tachycardia on patients' anxiety levels. We investigated 70 consecutive patients with paroxysmal supraventricular tachycardia (AV Nodal Reentrant Tachycardia (AVNRT), AV Reentrant Tachycardia (AVRT) or Atrial Tachycardia (AT)) who underwent a catheter ablation. The patients filled out the State and Trait Anxiety Inventory (STAI) before the ablation on the day of the procedure and after 3 months of a successful catheter ablation. State and trait anxiety scores were compared before and after 3 months of ablation. The results were analyzed between different age (<50 vs ≥50 y), gender and the type of paroxysmal supraventricular tachycardia (AVNRT vs AVRT/AT). Both state and trait anxiety scores improved significantly after catheter ablation. State anxiety score improved from mean 42.21±9.53 to 31.43±8.02 (p<0.001). Trait anxiety score improved from mean 45.76±7.80 to 39.80±7.33 (p<0.001). Present study demonstrates that the radiofrequency catheter ablation of paroxysmal supraventricular tachycardia by providing cure and eliminating the arrhythmia episodes significantly reduces both situational and general anxiety levels.

IMPACT OF RADIOFREQUENCY CATHETER ABLATION ON HEALTH-RELATED QUALITY OF LIFE ASSESSED BY THE SF-36 QUESTIONNAIRE IN PATIENTS WITH PAROXYSMAL SUPRAVENTRICULAR TACHYCARDIA

The aim of the study was to investigate the effect of catheter ablation on different aspects of health-related quality of life in association with patients' age, gender and the type of paroxysmal supraventricular tachycardia. We investigated 70 consecutive patients with paroxysmal supraventricular tachycardia (AV Nodal Reentrant Tachycardia (AVNRT), AV Reentrant Tachycardia (AVRT) or Atrial Tachycardia (AT)) who underwent a catheter ablation. The patients were asked to fill out the short form (SF-36) health questionnaire before the ablation on the day of the procedure and after 3 months of a successful catheter ablation and eight health concept scores (1. Physical functioning; 2. Role limitations due to physical health; 3. Role limitations due to emotional problems; 4. Energy/fatigue; 5. Emotional wellbeing; 6. Social functioning; 7. Bodily pain; and 8. General health) were assessed before and after ablation. All health concept scores improved significantly after successful catheter ablation procedure. The result for the whole group were as follows: 1. physical functioning improved from mean 61.42±24.82 to 77.15±18.80 (p<0.001). 2. Score for the role limitations due to physical health improved from 41.78±39.17 to 75.35±33.91 (p<0.001). 3. Score for the role limitations due to emotional problems improved from 48.07±42.32 to 80.46±33.81 (p<0.001). 4. Energy/Fatigue score improved from 56.71±19.97 to 68.78±16.40 (p<0.001). 5. Emotional wellbeing score improved from 58.22±17.31 to 71.88±14.33 (p<0.001). 6. Social functioning score improved from 68.39±24.51 to 81.00±19.12 (p<0.001). 7. Pain score improved from 59.82±28.65 to 80.57±20.58 (p<0.001) and 8. General health score improved from 48.42±15.26 to 62.57±15.43 (p<0.001). This study shows that catheter ablation which can effectively cure the patients from the paroxysmal supraventricular tachycardia significantly improves physical, emotional and social health scores by eliminating the arrhythmia episodes and associated symptoms and anxiety in patients with paroxysmal supraventricular tachycardia irrespective of patient demographics and the type of the SVT.

Influence of advancing age on clinical presentation, treatment efficacy and safety, and long-term outcome of inducible paroxysmal supraventricular tachycardia without pre-excitation syndromes: A cohort study of 1960 patients included over 25 years

AIM

To investigate the influence of increasing age on clinical presentation, treatment and long-term outcome in patients with inducible paroxysmal supraventricular tachycardia (SVT) without pre-excitation syndromes.

METHODS

Clinical and electrophysiological study (EPS) data, as well as long-term clinical outcome (mean follow-up 2.4±4.0 years) were collected in patients referred for regular tachycardia with inducible SVT during EPS without pre-excitation.

RESULTS

Among 1960 referred patients, 301 patients (15.4%) were aged ≥70 (70-97). In this subset, anticoagulants were prescribed in 49 patients following an erroneous diagnosis of atrial tachycardia and 14 were previously erroneously diagnosed with ventricular tachycardia because of wide QRS. Ablation was performed more frequently in patients ≥70 despite more frequent failure and complications. During follow-up, higher risks of AF, stroke, pacemaker implantation and death were observed in patients ≥70 whereas SVT recurrences were similar in both age groups. In multivariable analysis, age ≥70 was independently associated with higher risks of SVT-related adverse events prior to ablation (OR = 1.93, 1.41-2.62, p<0.001), conduction disturbances (OR = 11.27, 5.89-21.50, p<0.001), history of AF (OR = 2.18, 1.22-3.90, p = 0.009) and erroneous diagnosis at baseline (OR = 9.14, 5.93-14.09, p<0.001) as well as high rates of procedural complications (OR = 2.13, 1.19-3.81, p = 0.01) and ablation failure (OR = 1.68, 1.08-2.62, p = 0.02). In contrast, age ≥70 was not significantly associated with a higher risk of AF in multivariable analysis.

CONCLUSIONS

A sizeable proportion of patients with inducible SVT without pre-excitation syndromes are elderly. These patients exhibit higher risks of erroneous tachycardia diagnosis prior to EPS as well as failure and/or complication of ablation, but similar risk of SVT recurrence. These results support performing transesophageal EPS in most patients and intracardiac EPS in selected patients. EPS may furthermore prove useful in elderly patients with regular tachycardia, mainly by avoiding treatment based on an erroneous diagnosis.

You're the Flight Surgeon

DeFlorio PT. You're the flight surgeon: supraventricular tachycardia. Aerosp Med Hum Perfom. 2016; 87(12):1051-1053.

In-silico pre-clinical trials for implantable cardioverter defibrillators

Regulatory authorities require that the safety and efficacy of a new high-risk medical device be proven in a Clinical Trial (CT), in which the effects of the device on a group of patients are compared to the effects of the current standard of care. Phase III trials can run for several years, cost millions of dollars, and expose patients to an unproven device. In this paper, we demonstrate how to use a large group of synthetic patients based on computer modeling to improve the planning of a CT so as to increase the chances of a successful trial for implantable cardioverter defibrillators (ICDs). We developed a computer model of the electrical generation and propagation in the heart. This model was used to generate a large group of heart instances capable of producing episodes of 19 different arrhythmias. We also implemented two arrhythmia detection algorithms from the literature: Rhythm ID from Boston Scientific and PR Logic + Wavelet from Medtronic. Using this setup, we conducted multiple in-silico trials to compare the ability of the two algorithms to appropriately discriminate between potentially fatal Ventricular Tachy-arrhythmias (VT) and nonfatal Supra-Ventricular Tachy-arrhythmias (SVTs). The results of our in-silico trial indicate that Rhythm ID was less able to discriminate between SVT and VT and so may lead to more cases of inappropriate therapy. This corroborates the findings of the Rhythm ID Going Head to Head Trial (RIGHT), a clinical trial that compared the two algorithms in patients. We further demonstrated that the result continues to hold if we vary the distribution of arrhythmias in the synthetic population. We also used the same in-silico cohort to explore the sensitivity of the outcome to different parameter settings of the device algorithms, which is not feasible in a real clinical trial. In-silico trials can provide early insight into the factors which affect the outcome of a CT at a fraction of the cost and duration and without the ethical issues.

Paroxysmal Supraventricular Tachycardia: Pathophysiology, Diagnosis, and Management

Paroxysmal supraventricular tachycardia (PSVT) is a well-known and thoroughly studied clinical syndrome, characterized by regular tachycardia rhythm with sudden onset and abrupt termination. Most patients present with palpitations and dizziness, and their electrocardiogram demonstrates a narrow QRS complex and regular tachycardia with hidden or inverted P waves. PSVT is caused by re-entry due to the presence of inhomogeneous, accessory, or concealed conducting pathways. Hemodynamically stable patients are treated by vagal maneuvers, intravenous adenosine, diltiazem, or verapamil, hemodynamically unstable patients are treated by cardioversion. Patients with symptomatic and recurrent PSVT can be treated with long-term drug treatment or catheter ablation.

[Congenital heart defects in adulthood : Supraventricular tachycardia]

Supraventricular tachycardia (SVT) based on congenital substrates, such as accessory pathways or dual atrioventricular nodal properties, occur with an increased probability linked to specific congenital heart defects (CHDs). In the literature, the association of Ebstein's anomaly with accessory pathways and with Mahaim fibers is most prominent. Compared with patients with otherwise normal hearts, the clinical relevance of SVT is typically more severe and therefore antiarrhythmia treatment is a necessity in many cases. Diagnostics, pharmaceutical treatment, and interventional therapy of SVT in patients with CHD are often demanding owing to anatomical, hemodynamic, and electro-anatomical peculiarities. The use of antiarrhythmic medication is often limited because of intolerable side effects and a lack of reliability in suppressing arrhythmia relapses in the long term. Within the last 15-20 years catheter ablation has thus become established as the first-choice treatment for SVT, even in patients with CHD. However, rates of success, recurrence, and risks are still inferior to those observed in patients with a normally functioning heart owing to the co-existence of vascular and cardiac anomalies, surgically created alterations, an unusual electro-anatomy, and lower tolerance to hemodynamic changes. Successful treatment in patients with CHDs and SVT requires a deep understanding and knowledge of all the disciplines discussed above and should only be practiced in dedicated centers, as patient numbers are small and therefore experience is limited.

[Successful treatment of supraventricular tachycardia with a modified Valsalva manoeuvre]

Supraventricular tachycardia (SVT) is a frequent challenge in medical emergency units. Adenosine, the drug of choice, may cause severe discomfort. The Danish Society of Cardiology's National Treatment Guidelines for SVT recommend first aid treatment with ''vagus stimulation such as carotid massage and Valsalva manoeuvre''. A disadvantage of the Valsalva manoeuvre is that only 5-20% of the patients convert to sinus rhythm. We describe a case story of a patient, who was successfully treated with ''modified Valsalva'' as described in a recently published study wherein 43% of the patients converted to sinus rhythm compared to 17% in the control group.

Supraventricular Tachycardia in a Patient with an Interrupted Inferior Vena Cava

The noncoronary cusp and aortomitral continuity should be evaluated for early atrial activation when atrial tachycardias are noted to arise near the His bundle region, especially when the activation is diffuse around the His and when the P-wave morphology predicts a left atrial focus. In patients with congenital anomalies, alternate routes for catheter position need to be explored, including retrograde access for left atrial tachycardias and positioning of intracardiac echocardiography in the azygous vein for visualization of intracardiac structures. Consideration of remote magnetic navigation, if available, is another approach.