Cases Of Supraventricular Tachycardia Research Articles

Implementation of near zero fluoroscopy in supraventricular tachycardia ablation procedures: a single center experience

Abstract Background Supraventricular tachycardia (SVT) are common cardiac arrhythmias, and catheter ablation has proven to be a very effective treatment, but exposes patients and healthcare providers to radiation. "Near Zero Fluoroscopy" (NZF) techniques, utilizing advanced imaging, aim to reduce radiation exposure while maintaining efficacy. Purpose To present an analysis of near-zero fluoroscopy in SVT ablation procedures, in a tertiary center, since its implementation. Methods We prospectively enrolled 446 SVT-diagnosed patients for this study. All of them underwent NZF procedures using the same specific 3D mapping system, between January/19 and December/22. Patients with atrial fibrillation or macroreentrant atrial tachycardias or when a different mapping system was used, were excluded. All patients provided informed consent. Results Our population had 266 (60%) females and a median age of 39 (IQR 24-51) years. AVNRT was the most frequent arrhythmia documented (229 cases, 51%), followed by Accessory Pathways (AP) (201 cases, 45%) and focal atrial tachycardia (AT) (16 cases, 4%). The ablation success rate was high (405/418, 97%). There was no ablation attempt in 12 patients (9 APs and 3 ATs) and the unsuccessful ablations (7/418 cases, 1,67%) were APs. Overall, fluoroscopy time was 1.1 minutes (IQR 0-2.6). There was no statistically significant difference in the distribution of fluoroscopy time among the types of SVT based on the Kruskal-Wallis test (p 0.14). Observing trends of fluoroscopy use through time, we acknowledge the presence of a learning curve, leading towards shorter times of X-ray during procedures along the first 3 years of implementation of a near-zero strategy. Median times (IQR) of fluoroscopy were as follows: 2019 – 2.25 (0.45-3.4) min; 2020 – 1 (0-2.5) min; 2021 – 0 (0-1.9) min; 2022 – 0.55 (03.05) min. (see BoxPlot) Pairwise comparisons using the Wilcoxon rank-sum test with continuity correction revealed statistically significant differences in medians between all pairs of years, with p-values adjusted for multiple comparisons using the Bonferroni method (p<0.01). In 2022, fluoroscopy time increased, when compared to 2021. We believe this finding can be explained by the fact that in 2022, our department received a new fellow and a young EP consultant (coming from a center where NZF was not the standard for SVT ablation), both being in the lab on a daily basis, explaining this upward trend in fluoroscopy time. There were no acute complications requiring hospital admission or active treatment. Conclusion Our results emphasize the potential of near-zero fluoroscopy techniques to enhance safety and reduce radiation exposure while maintaining a high level of procedural efficacy in the treatment of SVT cases. Absence of acute complications highlighted the safety of these approaches.

Coronary sinus ablations in pediatric patients with supraventricular arrhythmias.

Intracoronary sinus ablations have been performed for various arrhythmical substrates. The aim of this study is to report our experience on pediatric patients of the safety and efficacy of ablations in the coronary sinus. This is a retrospective study of all patients who underwent ablations in the coronary sinus from October 2013 to October 2021 at a single center. Clinical presentation, type of arrhythmia causing tachycardia, ablation procedure, and outcome were recorded. A total of 27 patients were included in the study. Nineteen (69%) of those followed up received a diagnosis of Wolff-Parkinson-White syndrome (WPW), 4 (15%) were cases of supraventricular tachycardia with concealed accessory pathway (AP), 2 (8%) were cases of focal atrial tachycardia, and 2 (8%) were cases of permanent junctional reciprocating tachycardia. Negative delta wave was noteworthy especially in lead II in 11/19 (58%) cases and coronary sinus diverticulum was detected in the WPW cases. Of those with manifest AP (19 cases), 15 (79%) had a high-risk AP and the AP in all WPW cases was adenosine unresponsive. Radiofrequency (RF) catheter ablation was performed in 25/27 (93%) cases during the procedure, and 16/25 (64%) of these were irrigated RF catheters. No complications were observed in the follow-up, including coronary artery injury. Catheter ablation of supraventricular tachyarrhythmias can be accomplished effectively and potentially safely within the coronary sinus. Coronary sinus diverticula should be suspected in patients with manifest posteroseptal APs who have a previous failed ablation and typical electrocardiographic signs.

Supraventricular Tachycardia, Types and Immediate Management; Experience at a Tertiary Care Hospital of South Punjab

Objectives: The objective of this study was to determine efficacy of different optimal adenosine doses in children presenting with supraventricular tachycardia (SVT) at a tertiary care hospital. Methods: A descriptive case series design was undertaken at the Department of Cardiology at the Chaudhry Pervez Elahi Institute of Cardiology in Multan between June 2021 and June 2022. Both genders, age groups less than 14 years, and patients with SVT. The data collection procedure involved the use of a specialized proforma to record the findings of the study. Adenosine was quickly dispensed in escalating doses of 100, 200, and 300 μg/kg. The reaction was captured using a 12-lead ECG, and instances of pre-excitation were noted. The success of the therapy was assessed by identifying a sustained sinus rhythm for a period exceeding three minutes as a positive outcome. Results: A total of 71 participants were included in the study. Out of these, 55 (77.5%) were males. 33.8% presented with a predisposing factor. The most common predisposing factor was LRTI and diarrhea in 47 (66.2%) patients. As per our findings, out of 71 patients who were administered 100 ug per kg of adenosine for SVT, 27 (38.0%) while the remaining refractory 42 patients were administered 200 ug per kg of adenosine. Out of these 42, 26 (61.9%) reverted back to sinus rhythm i.e. 200 ug per kg dose of adenosine was effective in 61.9% cases of SVT. The remaining patients reverted back at 300 ug per kg dose of adenosine. Conclusion: A higher dose of 200 ug per kg was effective in 61.9% of cases. This indicates that a higher dose of adenosine is more effective in treating SVT in children. Additionally, the study found that LRTI and diarrhea were the most common predisposing factors for SVT in children. These findings can be useful in improving the management of SVT in children, especially when considering the optimal dose of adenosine for treatment. Keywords: Adenosine, Supraventricular tachycardia, Pediatric cardiology, Dose optimization, Predisposing factors Sinus rhythm

Prevalence and clinical significance of arrhythmias during labour in women with structurally normal hearts

ObjectivesExamine the association between arrhythmias and adverse maternal outcomes in women with structurally normal hearts.MethodsThis was a case–control study of women admitted in labour to one of eight hospitals of...

Wolff parkinson white syndrome in third trimester of pregnancy: A case report

Arrhythmias are the one of the most common forms of cardiac disease during pregnancy. Supraventricular tachycardia is the most common type of sustained arrhythmia presenting in pregnancy. During pregnancy, this can be difficult to diagnose as common symptoms like palpitation, shortness of breath and syncope. We presented our cases of supraventricular tachycardia in pregnancy during antenatal period. Risk factors for the development of supraventricular tachycardia and use of antiarrhythmic drugs management, during pregnancy and at Caesarean section are discussed. We recommend the use of adenosine as first line therapy.

Incidence of supraventricular tachycardia after inhaled short-acting beta agonist treatment in children

Introduction Albuterol can trigger supraventricular tachycardia (SVT). The clinical characteristics, incidence, and risk factors of SVT after inhaled SABA treatment in children are currently unknown. Through review of regional care delivery, we will describe cases of SVT during asthma treatment in hospital-based settings, define the incidence of SVT in our population, and evaluate risk factors of SABA-induced SVT. Methods We identified hospital-based care episodes of children 0-18 years old between 2006 and 2015 recorded in the Intermountain Healthcare EDW with either 1) diagnosis codes for both asthma and SVT or 2) both SABA and adenosine listed as billed medications. Controls were matched with cases by age and sex to determine risk factors for SVT after SABA using conditional logistic regression. Results Of 93 care episodes meeting criteria, we found 7 cases of SVT after SABA treatment in 6 patients over 10 years. In our population, the incidence of SVT is 3.9 per 10,000 episodes of SABA treatment, and 5.1 per 10,000 children with asthma receiving hospital-based asthma care. Two episodes of SVT followed treatment with only levalbuterol, three after only albuterol, and two after both albuterol and levalbuterol treatment. Five cases of SVT were converted to sinus rhythm with adenosine, one converted with synchronized electrical cardioversion, and one resolved spontaneously. No cases of SVT led to death. No examined variables were associated with SABA-induced SVT. Conclusions SVT is rare during hospital-based treatment for acute asthma using inhaled SABAs and has low morbidity and mortality.

SVT and Gram Negative Sepsis in Neonates

Supraventricular tachycardia is the most common tachyarrhythmia seen in fetuses, neonates and infants. Sustained SVT may lead to congestive cardiac failure. Neonatal supraventricular tachycardia is more commonly associated with other cardiorespiratory and congenital problems and is uncommon in an otherwise healthy infant. Supraventricular tachycardia is also caused by neonatal sepsis but has rarely been reported. Here, we report two cases of SVT (Supraventricular tachycardia) induced by neonatal sepsis. Two neonates, one male and another female, both born to Indian mother had tachycardia with heart rate > 220 beats/minute along with poor perfusion, tachypnoea, fever and deranged coagulation profile. Both the babies had culture positive gram negative sepsis with normal echocardiography and supraventricular tachycardia on electrocardiograms which were treated with anti arrhythmic drugs and treatment of sepsis. This case report gives further insight into one more presentation and complication of neonatal sepsis.

A scoring algorithm for the accurate differential diagnosis of regular wide QRS complex tachycardia.

The differential diagnosis of regular wide QRS complex tachycardia (RWQRST) remains the subject of numerous publications, all of which aim at diagnosis during the acute phase. Although an accurate diagnosis is necessary to make long-term decisions, it often leads to invasive testing. Criteria with high positive predictive values (PPVs) for diagnosis can be obtained by analyzing the electrocardiogram (ECG) data during RWQRST and comparing them with these data at baseline. By assigning points to these criteria, a scoring algorithm to accurately diagnose numerous patients can be obtained. A total of 352 consecutive patients with RWQRST were included. Two electrophysiologists blind to patient condition analyzed the 16 criteria considered as having high PPVs. A total of 149 (42.3%) cases were supraventricular tachycardia (SVT), and 203 (57.7%) cases were ventricular tachycardia (VT). A higher percentage of patients with VT had structural heart disease (86.7%vs 16.1%). Seven of the 16 criteria analyzed had PPVs>95%, and each criterion was assigned a score. A final score of -1 was indicative of SVT (PPV 98%); a score of 1 was indicative of VT (PPV 98%); and a score of ≥2 was indicative of VT (PPV 100%). A score of ≠0 was obtained for 51.7% of all cases of tachycardia, making it possible to reach a highly accurate diagnosis in approximately half of all cases. No cases of VT scored -1, and no cases of SVT scored ≥2. The current scoring system stands out for its high PPV (98%) and specificity (98%), enabling an accurate diagnosis for more than half of the patients.

Effectiveness of the modified valsalva maneuver in the emergency management of supraventricular tachycardia

Background: The return rate of supraventricular tachycardia (SVT) to sinus rhythm by the standard Valsalva maneuver (SVM) is as low as 5%–20%. Despite the limited available data in the literature, the modified Valsalva maneuver (MVM) is promising. We tested the effectiveness of the MVM for the emergency treatment of patients with SVT. Materials and Methods: In this cohort prospective study, 93 confirmed SVT cases with mean age of 47.88 ± 15.66 years and female: male ratio (1.73) across multiple centers underwent MVM. The reversion to sinus rhythm after 1 min of the maneuver, in the first or second attempt, was considered to be a success, and other conditions were considered to be a failure. Alternative therapies were administered for nonresponders. Results: The overall success rate of the reversion of SVT to sinus rhythm by using MVM in this study is 47.3%. In addition, the rate was not affected by medical and drug histories, and the rate was not substantially different among the patients having different sociodemographics, blood pressures, and pulse rate statuses. MVM has a high cardioversion rate when used for patients with SVT. We recommend using it instead of the SVM as the first-line nonpharmacologic therapy for SVT. Conclusion: The MVM has a very reasonable cardioversion rate in the setting of emergency treatment of SVT regardless of the associated sociodemographic and medical histories of patients.

368. Current practices in maternal monitoring during antiarrhythmic treatment for fetal SVT: A scoping review

Background In pharmacologic management of fetal supraventricular tachycardia (SVT), antiarrhythmic agents are administered to the pregnant patient serving as a vehicle of transplacental delivery to the fetus. Given that antiarrhythmic therapy can have profound maternal adverse effects, administration of initial loading and dose adjustments should involve deliberate attention to pharmacologic principles with close maternal monitoring for adverse effects. We reviewed current monitoring practices and maternal complications of transplacental antiarrhythmic therapy for fetal SVT. Methods A query of the Embase database for search terms ”Fetal” or ”Foetal” and ”Supraventricular Tachycardia” or ”SVT” yielded 93 titles, of which 19 articles detailing the modalities of therapy for Fetal SVT were reviewed. Results The 19 articles represented 565 cases of fetal SVT, 111 of which had developed hydrops fetalis. Of these cases, 184 received a course of digoxin alone and 33, 56, and 5 cases received a combination therapy of digoxin with flecainide, sotalol, or amiodarone. Flecainide, Sotalol, and amiodarone were given as monotherapy in 89, 77, and 6 cases, respectively. Maternal monitoring information was available in 15 studies. Investigators performed electrocardiograms (EKGs) at baseline and during follow-up in 12 studies, and monitored electrolytes in five. Two studies reported a mandatory cardiologist consultation for all mothers and two studies considered performing echocardiography in select mothers. Digoxin and flecainide levels were measured in eight and four studies, respectively. Toxicity was reported in 5 patients: two on digoxin monotherapy, two on flecainide monotherapy, and one on combination of digoxin and flecainide. Conclusion Pharmacologic management of fetal SVT is generally safe for mothers with normal baseline cardiac assessments and close monitoring of symptoms, EKG, electrolytes, and/or drug levels. Future prospective studies on the treatment of fetal SVT should also include a systematic monitoring strategy for mothers, with consistent reporting of adverse reactions.

Age makes a difference: Symptoms in pediatric supraventricular tachycardia.

BackgroundSupraventricular tachycardia is a group of rhythm disturbances that affect 1 in 300‐1200 Australian children annually. The differentiation of supraventricular tachycardia (SVT) symptoms and age of onset according to their subtype is not well understood in the pediatric population. Most studies rely on ECG criteria only to characterize the subtype of the SVT, which is not applicable to all subtypes. The purpose of this study was to identify the symptoms and ages of onset of SVT subtypes, and to analyze whether ethnicity or severity correlated with the SVT subtype confirmed in an invasive Electrophysiology (EP) study.MethodsA retrospective analysis and prospective survey evaluated 364 patients who underwent an EP study at The Royal Children's Hospital, Melbourne between 2009 and 2015. Age of onset, symptoms, and ethnicity were collected by phone survey or medical records in addition to EP study diagnostic data, medication status, and follow‐up information about their symptom status following EP procedure. Patients were grouped according to their SVT subtype. Data analysis was performed using chi‐squared, Fisher's exact, and ANOVA statistical tests to determine associations between SVT substrates.ResultsTwo hundred and thirty‐three suitable cases of SVT were identified (131 men, 102 women) aged between 0 and 18 years. Atrioventricular Reentrant Tachycardia (AVRT) (n = 153) was the most common SVT subtype, followed by Atrioventricular Nodal Reentrant Tachycardia (AVNRT) (n = 55), Atrial Tachycardia (AT) (n = 17), and other SVT subtypes (n = 8) which included Atrial Fibrillation, Atrial Flutter, and Junctional Tachycardia. There was a male predominance in all subtypes, except for AVNRT. AVNRT patients had palpitations, dyspnoea, dizziness, and anxiety more than any other group, AVRT patients complained of vomiting most and patients with AT had the most fatigue. The mean age of symptom onset varied among groups, being earlier in AVRT, later in AVNRT with a significant difference between AVRT with unidirectional retrograde accessory pathway (URAP) and AVNRT subtypes (P < 0.01).ConclusionSome specific symptoms were strong discriminators between different SVT subtypes. Ethnicity did not have strong correlations with SVT subtype incidence. This study was able to show clinical differences among children with SVT due to AVRT (URAP) compared to AVNRT, allowing the prognosis and intended management of pediatric SVT to be anticipated by less invasive means.

Stroke volume ratio derived from magnetic resonance imaging as an indicator of interventricular dyssynchrony predicts future cardiac event in patients with biventricular Fontan circulation.

The prognostic factors in patients with biventricular heart who underwent Fontan surgery remain unclear. This study wanted to assess the hypothesis that interventricular dyssynchrony evaluated by cardiac magnetic resonance imaging (MRI) can predict future cardiac events in patients with biventricular heart who have undergone Fontan surgery. We prospectively enrolled consecutive patients with biventricular Fontan circulation from 2003 to 2016, and performed protocolized cardiac MRI. We determined the stroke volume ratio (SVr) using the following formula to assess interventricular dyssynchrony: (stroke volume (SV) of the two whole ventricles)/(SV of the right ventricle + SV of the left ventricle), by tracing cine MRI data. If interventricular dyssynchrony existed, blood flowed and returned to each ventricle through the ventricular septal defect; therefore, the SVr in this instance should be less than 1.0. We enrolled 40 patients. SVr ranged from 0.81 to 1.0 (median 0.95). Low SVr (< 0.95) was associated with worse New York Heart Association functional class, longer QRS duration, right bundle branch block, low biventricular indexed stroke volume, and low biventricular ejection fraction. During the follow-up period (median 53.5months), 10 cardiac events occurred (six cases of acute exacerbation of heart failure, three cases of supraventricular tachycardia, and one case of exacerbation of protein-losing enteropathy). Univariate analysis showed four clinical predictors: SVr < 0.95 [hazard ratio (HR) 9.3, 95% confidential interval (CI) 1.7-171.5]; biventricular ejection fraction < 0.45 (HR 9.4, 95% CI 2.2-65.3); left ventricular indexed end-diastolic volume > 73mL/m2 (HR 4.5, 95% CI 1.1-15.7); and the presence of the aorta directly arising from the right ventricular conus (HR 5.8, 95% CI 1.1-106). SVr derived from MRI can predict future cardiac events in Fontan patients with biventricular hearts.

Flecainide as first-line treatment for fetal supraventricular tachycardia

Objective: The aim of this study was to evaluate utilization, efficacy, and side effects of flecainide treatment as first-line agent in patients with fetal supraventricular tachycardia (SVT).Method: This retrospective review was conducted on 23 consecutive fetal tachyarrhythmia cases that met inclusion criteria. If the treatment was necessary, then flecainide was used as first-line treatment in all cases.Result: Among the study group, there were 21 (91.3%) cases of SVT and 2 (8.6%) cases of Atrial Flutter (AF). Sixteen fetuses had persistent SVT and five fetuses had intermittent SVT. We treated 17 fetuses with flecainide monotherapy and 15 of them converted to sinus rhythm and remaining two fetuses were refractory to monotherapy. The median time to conversion to sinus rhythm was 3.8 ± 1.6 days. Only one fetus (20%) among the intermittent SVT cases required anti-arrhythmic treatment.Conclusion: Our study has demonstrated that flecainide is an effective first-line treatment for fetal SVT with high success rate (88.2%), low side effect profile and relatively easy utilization. Based on the current study and recently published article results, flecainide can be recommended as the drug of first choice for treatment of fetal SVT cases.

Clinical analysis of 19 cases of pregnant women with rapid arrhythmia in the treatment of radiofrequency catheter ablation

paroxysmal palpitation, chest tightness, dizziness, and blurred vision. Arrhythmia types: 1 case of atrial flutter and atrial tachycardia, 1 case of atrial flutter and atrial fibrillation, 1 case of atrial fibrillation, 3 cases of supraventricular tachycardia, 1 case of atrial tachycardia and supraventricular tachycardia, 4 cases of ventricular tachycardia, 3 cases of ventricular premature beats and ventricular tachycardia, and 5 cases of atrial tachycardia. All cases were treated by drugs, but all failed 2 cases of them were performed esophageal pacing and cardioversion and also failed.(2)Treatment plan: 19 cases after treatment of arrhythmia, completely terminated, the first 7 patients(from 2002 to 2014)were operated in a small amount of radiation under the guidance, the other 12 patients(after 2015)were carried out in the Ensite NavX mapping system, whichwere operated with zero radiation. Complications and adverse reactions: 1 case of uterine contraction end operation and was gived magnesium sulfate 3 days intravenous inhibition of uterine contractions, 1 case occurred vagal reflex caused by reduced blood pressure and was gived fluid infusion utill normal blood pressure.(3)Maternal and neonatal outcomes: in addition 1 case of pregnancy to give up, the remaining 18 cases were full-term pregnant women, including 4 cases of vaginal delivery and 14 cases of cesarean section. The survival neonates were followed up for 1 to 14 years, average(2.0 ± 2.9)years. The infants were well developed during the follow-up period. Conclution: Radiofrequency catheter ablation is a safe and effective method for the treatment of pregnancy complicated with rapid arrhythmia.

GW26-e0685 Identification of accessory pathways connecting the right atrial appendage and right ventricle

To summarize the experience and outcomes of radiofrequency catheter ablation (RFCA) of accessory pathways connecting the right atrial appendage (RAA) and right ventricle (RV) in our center. We reviewed all the adult (≥14 years) 489 cases of supraventricular tachycardia due to accessory pathways (

OUTCOMES OF EMPIRIC SLOW PATHWAY ABLATION IN DOCUMENTED BUT NON-INDUCIBLE SUPRAVENTRICULAR TACHYCARDIA

Empiric slow pathway ablation (ESPA) is a slow pathway ablation in patients with non-inducible supraventricular tachycardia (SVT) at electrophysiology study (EPS). We earlier documented that the practice of ESPA is common in Canada (5-10% of SVT cases); evidence to support this approach is limited. The aim of this study is to assess efficacy and safety of ESPA in adults. A multi center cohort study of patients who had ESPA between January 2008 and October 2013 was performed. Patients were identified by screening reports of consequent SVT ablation procedures. Forty-three (5%) out of 859 SVT ablation procedures were identified as ESPA. The median age was 53 (IQR: 24) years, 63% were female; none had structural heart disease. All patients had pre-EPS documentation of SVT (either strip or ECG). In 23 (53.5%) cases, pre-EPS ECG convincingly showed short RP tachycardia. Frequency of pre-procedural episodes ranged between daily to quarterly. During diagnostic EPS, none of the patients had inducible SVT or explicit signs of an accessory pathway. Thirty-two (74.4%) patients had DAVNP plus echo beats, 9 (20.9%) patients had DAVNP only, and 2 (4.7%) patients had no DAVNP. Junctional rhythm (JR) as procedural endpoint was noted in 39 (90.7%) patients. In 18 (41.9%) patients, abolishment of DAVNP was achieved. No complications were encountered. A median follow up of 17 months (6 to 31 months) revealed 83.7% (36 of 43) success rate, defined as absence of pre-procedural symptoms and any documented sustained arrhythmia during follow-up. All recurrences (n=7) occurred within 2 months after the procedure. As compared to patients with recurrence (n=7), patients with no recurrence (n=36) had significantly higher prevalence of clinical short RP tachycardia (61.1% vs. 14.3%, p=0.038), and EPS finding of DAVNP plus echo beats (80.6% vs. 42.9%, p=0.034). Groups were similar with respect to other baseline characteristics. In patients with DAVNP, presence of echo beats on EPS was associated with a higher 2-year probability of freedom from recurrence (90.6% vs. 55.6%, Long-rank P=0.023). Absence of DAVNP plus echo beats on EPS was the only predictor of recurrence in Cox proportional hazards model (p=0.048. HR: 4.53 95%CI 1.013 to 20.23). JR alone versus JR plus abolishment of DAVNP as procedural endpoints had no influence on long-term success (p=0.27). ESPA is a reasonable approach in patients with documented SVT, in particular short RP tachycardia, who are not inducible at EPS. Larger studies are required to assess this practice.

Use of adenosine in the treatment of supraventricular tachycardia in a pediatric emergency department.

Supraventricular tachycardia (SVT) is the most frequent arrhythmia requiring treatment in childhood, with an estimated incidence of 1/100 to 1/250 children. The treatment of choice of the acute event is intravenous adenosine. This study aimed to determine if doses of adenosine higher than previously described are needed to successfully revert SVT in children. This is a retrospective study of SVT cases in a tertiary hospital from January 2007 to December 2011. A total of 44 episodes of SVT were recorded in 26 patients. Mean age was 3.1 years. In 39 patients (89%), adenosine was administered, reverting to stable sinus rhythm in 29 episodes, which represents an effectiveness of 75%. In relation to the number of doses administered, 12 patients (30%) received a single dose, with a mean (SD) response dose of 112 (35) µg/kg; 16 (41%) received 2 doses, with a mean (SD) response dose of 188 (55) µg/kg; and 9 (24%) received 3 doses, with a mean (SD) response dose of 249 (108) µg/kg. Finally, in 2 patients (4%), 4 doses of adenosine were administered, with only 1 of them responding to a dose of 300 µg/kg. The mean (SD) dose that reverted the SVT to normal sinus rhythm was 173 (84) µg/kg, and the mean (SD) number of doses administered was 1.7 (0.8) (range, 1-4). Sixty-six percent were discharged home, without the need to be transferred to pediatric intensive care unit or pediatric ward. Most of the patients with SVT episodes require treatment with more than 1 dose of adenosine. Doses higher than the usually described in the guidelines are necessary to revert SVT. Most patients can be discharged home from the emergency department, without the need of hospital admission.

Supraventricular tachycardia during pediatric anesthesia: a case series and qualitative analysis

Study ObjectiveTo perform a qualitative analysis of noncardiac patients who developed suspected intraoperative supraventricular tachycardia (SVT) during general anesthesia. DesignRetrospective database analysis and chart review. SettingOperating room of a university-affiliated children’s hospital. MeasurementsThe records of children without cardiac disease who received general anesthesia at The Children’s Hospital of Philadelphia from July 1998 through June 2011 were reviewed. Patients with heart rate values above 180 beats per minute were identified, as were specific medications or key words in the free-text fields of the anesthesia records that would be indicative of a tachyarrhythmia. Each case was reviewed by at least two authors; each patient was assigned a diagnosis classification of “highly suspicious” or “unlikely” SVT. The highly suspicious SVT cases were examined in detail to determine the specific aims. Main Results36 subjects out of a total of 285,353 anesthetics administered during the study period were suspected by the anesthesia care team to have had an episode of intraoperative SVT: 22 were “highly suspicious” events, and 14 were “unlikely” events. The highly suspicious SVT events occurred in all phases of anesthesia, and none led to any hemodynamic instability. Effective treatments included vagal maneuvers, pharmacologic antiarrhythmics, or no treatment if the event resolved spontaneously before treatment. Six patients had outpatient follow-up and three received antiarrhythmic medications to control ongoing SVT. ConclusionsSVT during the intraoperative period in noncardiac pediatric patients was uncommon. When it occurred, it was not associated with clinically significant patient morbidity. For some patients, the anesthesia unmasked a predisposition for re-entrant SVT and those patients remained on maintenance antiarrhythmic therapy following discharge home.

Comparison of the “Real-life” Diagnostic Value of Two Recently Published Electrocardiogram Methods for the Differential Diagnosis of Wide QRS Complex Tachycardias

The diagnostic values of the aVR lead or "Vereckei algorithm," and the lead II R-wave peak time (RWPT) criterion, recently devised for the differential diagnosis of wide QRS complex tachycardias (WCTs), were compared. A total of 212 WCTs (142 ventricular tachycardias [VTs], 62 supraventricular tachycardias [SVT], and eight preexcitation SVTs) from 145 patients with proven electrophysiologic diagnoses were retrospectively analyzed by seven examiners blinded to the electrophysiologic diagnoses. The overall test accuracy of the Vereckei algorithm was superior to that of the RWPT criterion (84.3% vs. 79.6%; p = 0.0003). The sensitivity of the Vereckei algorithm for VT diagnosis was greater than that of RWPT criterion (92.4% vs. 79.1%; p < 0.0001). The negative predictive value (NPV) for the Vereckei algorithm was also greater (77.8%; 95% confidence interval [CI] = 73.6% to 82.1%) than that of the RWPT criterion (61.6%; 95% CI = 57.6% to 65.6%). The specificity of the Vereckei algorithm was lower than that of the RWPT criterion (64.7% vs. 80.9%; p < 0.0001). The positive predictive value (PPV) was also lower for the Vereckei algorithm (86.4%; 95% CI = 84.4% to 88.4%) than for the RWPT criterion (90.9%; 95% CI = 89.1% to 92.8%). Incorrect diagnoses made by the Vereckei algorithm were mainly due to misdiagnosis of SVT as VT (65.7% of cases), and those made by the RWPT criterion were due to the more dangerous misdiagnosis of VT as SVT (72.5% of cases). The Vereckei algorithm was superior in overall test accuracy, sensitivity, and NPV for VT diagnosis and inferior in specificity and PPV to the RWPT criterion. All of these parameters were lower in "real life" than those reported by the original authors for each of the particular electrocardiographic methods.

MediGuide in supraventricular tachycardia: initial experience from a multicentre registry

Currently, fluoroscopy-based catheter visualization is the standard modality in invasive electrophysiological procedures. Recently a new technology for non-fluoroscopic visualization of diagnostic (since 2010) and ablation catheters (since May 2012) has been introduced. The MediGuide™-Technology (MediGuide) projects catheter tips on prerecorded cine loops in a high time resolution. We report on MediGuide-based supraventricular tachycardia (SVT) cases [atrioventricular nodal reentry tachycardia (AVNRT), atrioventricular reentry tachycardia (AVRT), Wolff-Parkinson-White syndrome (WPW), ectopic atrial tachycardia (EAT) and typical atrial flutter) from two European centres. In all patients, diagnostic and/or ablation catheters with a special sensor were used to perform the ablation procedures. All procedural data such as acute success, duration of the procedure, fluoroscopy time, and dose and patients' characteristics were analyzed and compared with conventionally ablated patients (n = 1865). Procedure-related complications during the hospital stay were recorded. A total of 24 consecutive patients were analyzed: no significant difference to the control group was seen in the baseline characteristics. The MediGuide patients were predominantly male (66%), aged 58 ± 14 years and were ablated for 6 AVNRT (25%), 4 AVRT/WPW (17%), 1 EAT (4%), and 13 typical atrial flutter (54%). The acute success rate was 100% (98% in the control group, n.s.). The median fluoroscopy time was 0.5 ± 1.4 min (10.2 ± 9.6 in the control group, P < 0.001), the median fluoroscopy dose was 187 ± 554 cGy cm(2) (996 ± 2593 cGy cm(2), P < 0.05). Mean procedure time was 70 ± 25 min (60 ± 36 min, n.s.). No complications during the hospital stay were recorded. In several different forms of supraventricular tachycardias the MediGuide-Technology contributed to a dramatic reduction in irradiation exposure. With a median fluoroscopy time of 30 s all SVT cases were effectively performed with no complications; the fluoroscopy burden can be significantly reduced not only for the patient but also for the nurses and the physicians performing the case. The overall procedure times are not prolonged due to the use of MediGuide Technology compared with a control group of >1800 patients undergoing conventional ablation procedures.