Recurrent Supraventricular Tachycardia Research Articles

The impact of His bundle location and direction on the efficacy and safety of ablation.

The impact of the His bundle location and distance from the ablation site on ablation efficacy and complication risk remains unexplored. We determined the correlation between age, height, body mass index (BMI), and the His bundle location, and whether the distance between the His bundle and ablation target (DHIS-ABL) affects ablation safety and efficacy. Overall, 346 patients with atrioventricular nodal re-entrant tachycardia (AVNRT) and 96 with atrioventricular re-entrant tachycardia (AVRT) were retrospectively analyzed. The distance between the His bundle and the coronary sinus ostium (DHis-CS), the height of the His bundle (HHIS), and DHIS-ABL were measured. Electrocardiograms were obtained 3 months post-ablation to assess recurrence and complications. Multiple linear regression showed that HHIS was negatively correlated with age in both groups. In AVNRT patients, DHIS-ABL was associated with age, height, and BMI; DHIS-CS was only negatively correlated with age. In AVRT patients, there was no significant correlation between the DHIS-ABL and age, height, or BMI. The recurrence rates in the AVNRT and AVRT groups were 0.9% and 8.7%, respectively. Subgroup analysis showed that patients with DHIS-ABL≤10mm had a higher recurrence rate than those with DHIS-ABL>10mm (p=.013). The incidence of third-degree atrioventricular block (AVB) complications was 0.2%. HHIS was negatively correlated with age but not with height and BMI. The DHIS-ABL correlated with age, height, and BMI in AVNRT patients. A short DHIS-ABL led to a higher rate of supraventricular tachycardia recurrence; whether this affects AVB risk warrants further studies with larger sample sizes.

Longitudinal reduction in fluoroscopy with continued use of 3-dimensional electroanatomic mapping systems in catheter ablation of supraventricular tachycardia – then and now

BackgroundCatheter ablation is a first-line treatment for symptomatic, recurrent supraventricular tachycardia (SVT). This study aims to demonstrate if 3D-electroanatomic mapping (EAM) during SVT ablation reduces fluoroscopy time (FT) and determine if further reductions in FT are observed longitudinally. MethodsAll cases of SVT ablation between May 2011–May 2022 at a single tertiary centre were prospectively recruited. FT between the cohorts with and without EAM were compared. Within the EAM subset, the trend of FT across the years was analysed. ResultsThere were 1758 cases included, 563 without EAM, 1195 with EAM. EAM was associated with a longer procedure time (mean + 8.8 min, p = 0.001), but with mean reductions in FT and dose area product (DAP) by 19.6 min and 18 621 mGy*cm2 respectively (p < 0.001). There was comparable efficacy without any increase in complication rates. Over time (2011–2022), further reduction in FT of 0.9 min year on year was observed (p = 0.001). Between 2011 and 2017, there was a significant reduction in FT of 1.1 min year on year (p = 0.019), which was not observed from 2017 onwards (p = 0.061). The greatest reduction in FT was after the first year of adoption. ConclusionEAM in SVT ablation reduces fluoroscopy use. FT was initially observed to reduce further over time before plateauing, likely due to increased operator experience. While there is increased interest in zero fluoroscopy SVT ablation, complementary use of fluoroscopy may still be necessary in complex cases.

Tachyarrhythmias burden in hospitalized patients with cancer: A nationwide propensity matched analysis.

e24032 Background: Remarkable progress has been made in the management of cancer with the advent of new therapies. However, significant concern exists over the cardiotoxic effects of chemotherapy and radiation therapy. We aim to evaluate the different cardiac tachyarrhythmias in hospitalized cancer patients. Methods: The national readmission database (2016-2020) was queried to identify all-cause admissions for patients with active malignancy of any origin. Multivariate regression model was used to obtain adjusted odds ratio (aOR). Univariate screening was utilized for regression building model. Multicollinearity among different variables were determined by variation inflation factor (VIF). VIF &gt; 5 was taken as cut off for significant collinearity. Cohorts were stratified based on the presence of tachyarrhythmias. A propensity score matching (PSM) model, implementing complete Mahalanobis Distance Matching within the Propensity Score caliper (set at 0.2), matched cancer patients with and without tachyarrhythmias. Inverse Probability weighting(IPW) was utilized, and Pearson's x2 test was applied to the PSM matched cohorts to compare outcomes. Results: Among 10.6 million all-cause hospitalizations of cancer patients, about 1.7 million (16%) developed tachyarrhythmia. On a propensity-matched cohort, patients with active malignancy had the highest rates of atrial fibrillation (AF) (14.1%), followed by supraventricular tachycardia (SVT) (1.1%), ventricular tachycardia (VT) (0.8%) and atrial flutter (AFL) (0.4%) [p &lt; 0.001]. Cancer patients with tachyarrhythmias had increased in-hospital mortality. The mortality was highest for VT (aOR 3.9, CI 3.7 - 4.01, P &lt; 0.001), followed by SVT (aOR 2.6,CI 2.51 - 2.67, p &lt; 0.001), AFL (aOR 2.5, CI 2.38 - 2.59, p &lt; 0.001 ) and AF (aOR 1.54, CI 1.52 -1.56, p &lt; 0.001). Readmissions among patients who developed tachyarrhythmias during index hospitalization showed that 18.7% and 34.3 % had recurrent AF, 17.4% and 33% had recurrent SVT, 17.3% and 32.1% had recurrent AFL, and 15.4% and 31.1% developed recurrent VT at 30 and 90- day readmissions respectively. Resource utilization was also higher in the cohort complicated by tachyarrhythmias, with the highest length of stay (LOS)(7 vs 4 days) and total cost ($31,718 vs $17,659) in hospitalization complicated by VT (p &lt; 0.001). A similar increase in LOS and total inpatient cost was also seen in cancer patients whose hospitalization was complicated with SVT, AFT and AF compared to patients without arrhythmias (p &lt; 0.01). Conclusions: Hospitalizations in cancer patients complicated by tachyarrhythmias were associated with higher in-hospital mortality, LOS, and adjusted cost. VT is associated with the highest mortality; however, AF appears to be most prevalent during index admission and readmissions. This study signifies the importance of close cardiac monitoring in hospitalized cancer patients to prevent adverse outcomes.

Multiple recurrent supraventricular tachycardia in infantile tuberous sclerosis complex: management requiring triple-drug therapy.

We report the case of a female neonate admitted to the neonatal ICU with a rapid, narrow-complex tachyarrhythmia determined to be supraventricular tachycardia. Multimodality imaging and genetic testing confirmed a diagnosis of tuberous sclerosis complex with multiple cardiac rhabdomyomas. At 13 days of age, the patient was readmitted, exhibiting recurrent supraventricular tachycardia non-responsive to first-line treatment. Management required triple-drug therapy, whereafter the patient remained stable without recurrences. This is a rare report of supraventricular tachycardia in a functionally normal heart with the occurrence of supraventricular tachycardia due to structural abnormalities, with the possibility of multiple concealed accessory pathways.

History of surgical treatment of cardiac arrhythmias in Germany : Surgical treatment of ventricular tachycardia and supraventricular tachycardia, especially pre-excitation syndromes (WPW)

The history of surgical treatment of ventricular tachycardias (VT) is short, lasting from 1978 until 1993. "Indirect procedures" with infarct scar resection were performed without electrophysiologic studies, whereas "direct procedures" consisted of either complete endocardial incisions ("encircling endocardial ventriculotomy") or large endocardial resections ("endocardial peel-off" technique) after precise epicardial and endocardial mapping procedures. In Germany, the first to report on intra-operative electrophysiologic mapping for VT treatment were Ostermeyer, Breithardt and Seipel in 1979. In 1981, the Hannover group (Frank, Klein) published their first results of surgical treatment of VT. In 1984, Ostermeyer et al. demonstrated that apartial endocardial incision resulted in more beneficial results with less myocardial damage (8% versus 46%) than applying acomplete encircling incision. In 1987, the Düsseldorf group reported treatment results of 93patients. After 5years, 77% had no VT recurrence, while total mortality after 1year was 11% and after 5years 30%. In 1992, the Hannover group reported results of 147patients after endocardial resection for VT. Total mortality after 3years was 27%; recurrence of VT events occurred in 18% of the surviving cohort.The history of surgical procedures for supraventricular tachycardia (SVT), in particular Wolff-Parkinson-White (WPW) syndrome, is even shorter than that of surgery for VT. As early as 1969, Sealy, Gallagher and Cox reported the first cases of surgical intervention for WPW syndrome via endocardial access in cardioplegic arrest. In 1984, Guiraudon and Klein reported on anew procedure with epicardial access to the accessory bundle without cardioplegia in laterally localised conduction pathways. In Germany, too, the groups in Düsseldorf (Ostermeyer, Seipel, Breithardt, Borggrefe) from 1980 and the Hannover group (Frank, Klein and Kallfelz) from 1981 performed surgical procedures for WPW syndrome. In 1987, Borggrefe reported on 18patients with WPW syndrome and atrial fibrillation who had undergone surgery. After 2years, 14 of 18patients had no recurrences of tachycardia; in 1989, Frank, Klein and Kallfelz (Hannover) reported on 10children (2-14 years) operated on using the cryoablation technique. Between 1984 and 1992, atotal of 120 patients with SVT, mostly WPW syndrome, were operated on in Hannover; after 42months, 12patients had a recurrence of SVT. Two patients died during the reoperation.

Outcomes of Infant Supraventricular Tachycardia Management Without Medication.

Most infants presenting with supraventricular tachycardia (SVT) are treated with an antiarrhythmic, primarily to prevent unrecognized future episodes that could lead to tachycardia-induced cardiomyopathy. A common practice at our institution is to not treat after the first presentation of infant SVT and instead educate parents on heart rate monitoring and reasons to present to care. The goal of this study was to evaluate the outcomes of non-pharmacologic treatment of infant SVT at first presentation and compare to outcomes of infants treated with an antiarrhythmic. This was a retrospective single center study of all infants presenting with a first episode of SVT from 2014 to 2021. Excluded were patients with a non-reentry type tachyarrhythmia, atrial flutter, long-RP tachycardia, congenital heart disease, or abnormal ventricular function. Sixty-four infants were included in the study. Thirty-six were managed without an antiarrhythmic. SVT recurred in 28% of the non-treatment group vs 50% in those treated with antiarrhythmics, p = 0.12. Of the patients admitted to the hospital, those in the non-treatment group had a shorter length of stay, 1(IQR 1-1) vs 3(IQR 2-4) days, p < 0.01. Non-treated patients were less likely to present to the emergency department for recurrent SVT, 6% vs 32%, p < 0.01. Neither group had a patient develop tachycardia-induced cardiomyopathy. For infants with structurally and functionally normal hearts, non-treatment combined with parental education after the first episode of SVT does not lead to worse outcomes. This approach avoids the burden of medication administration in an infant and may have the added benefit of empowering parents to feel comfortable managing clinically insignificant tachycardia at home.

Long-Term Follow-Up In Paroxysmal Atrial Fibrillation Patients With Documented Isolated Trigger.

Supraventricular tachycardias may trigger atrial fibrillation (AF). The aim of the study was to evaluate the prevalence of supraventricular tachycardia (SVT) inducibility in patients referred for AF ablation and to evaluate the effects of SVT ablation on AF recurrences. 249 patients (mean age: 54 ± 14 years) referred for paroxysmal AF ablation were studied. In all patients, only AF relapses had been documented in the clinical history. 47 patients (19%; mean age: 42 ± 11 years) had inducible SVT during the electrophysiological study and underwent an ablation targeted only at SVT suppression. Ablation was successful in all 47 patients. The ablative procedures were: 11 slow-pathway ablations for atrioventricular nodal re-entrant tachycardia; 6 concealed accessory pathway ablations for atrioventricular re-entrant tachycardia; 17 focal ectopic atrial tachycardia ablations; 13 with only one arrhythmogenic pulmonary vein. No recurrences of SVT were observed during the follow-up (32 ± 18 months). 4 patients (8.5%) showed recurrence of at least one episode of AF. Patients with inducible SVT had less structural heart disease and were younger than those without inducible SVT. A significant proportion of candidates for AF ablation are inducible for an SVT. SVT ablation showed a preventive effect on AF recurrences. Those patients should be selected for simpler ablation procedures tailored only to the triggering arrhythmia suppression.

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

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. We present a case of a neonate admitted with fever and nasal congestion. The neonate was tested positive for SARS-CoV-2. Supraventricular tachycardia (SVT) was diagnosed during his hospitalization in the neonatal intensive care unit. 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. 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. 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.

Impact of 3-dimensional electroanatomic mapping systems on fluoroscopy reduction in catheter ablation of supraventricular tachycardia - then and now

Abstract Funding Acknowledgements Type of funding sources: None. Background Catheter ablation is an effective first-line treatment for symptomatic and recurrent supraventricular tachycardia (SVT). The advent of 3D electroanatomic mapping (EAM) has led to a reduction in fluoroscopy use and consequently lower radiation exposure for patients and staff during SVT ablation. Purpose The aims of this study are to demonstrate if the use of EAM during SVT ablation reduces fluoroscopy time (FT), and determine if further reductions in FT are observed longitudinally. We hypothesise that over time, with continued use and wider adoption of EAM, greater operator experience, and technological advancements in EAM, there will be further reductions in radiation exposure as estimated by FT. Methods All cases of atrioventricular nodal re-entry tachycardia (AVNRT), atrioventricular re-entry tachycardia (AVRT), and/or atrial tachycardia (AT) ablation between May 2011 to May 2022 at a tertiary centre were prospectively recruited. FT between the groups with and without EAM were compared. Within the EAM subset, the trend of FT across the years was also analysed. Results Over this 11-year period, there were 1758 cases of SVT ablation (565 without EAM; 1193 with EAM). Between the two groups, there were no significant differences (p &amp;gt; 0.05) in age, sex, history of structural heart disease and/or ischaemic heart disease, stereotaxis use, and diagnosis (AVNRT, AVRT, AT). Cases using EAM were more likely to have &amp;gt;1 SVT ablated during the procedure (0.04) and require intracardiac echocardiography (ICE) (p &amp;lt; 0.001). The use of EAM was associated with mean reductions in FT and dose area product (DAP) by 19.6 minutes and 18 581 mGy*cm2 respectively (both p &amp;lt; 0.001). EAM was also associated with a longer procedure time (mean +8.8 minutes, p &amp;lt; 0.001). There was no difference in radiofrequency application time between the two groups (p = 0.143). After controlling for potential confounding factors including age, sex, use of stereotaxis, use of ICE, type and number of SVT, history of prior ablation, and structural heart disease and/or ischaemic heart disease, we found over time (2011-2022), further reduction in FT was observed, with a mean reduction of 0.9 minutes year on year (p &amp;lt; 0.001). EAM was gradually adopted through the years with the number of cases per year plateauing after 2017. Between 2011-2017, there was a significant reduction in FT (mean of -1.1 minute year on year, p = 0.020), which was not observed from 2017 onwards (p = 0.088). The greatest reduction in FT was observed after the first year of adoption, with a mean reduction of 6.9 minutes between 2012-2013. Conclusion This demonstrates that use of EAM in SVT ablation reduces FT and fluoroscopy DAP. There was no incremental benefit observed after 6 years of EAM adoption likely related to operator experience. While there is increased interest in zero fluoroscopy SVT ablation, complementary use of fluoroscopy may still be necessary in select complex cases.

Prognostic value of cardiac troponin in elderly patients with paroxysmal supraventricular tachycardia: A multicenter study

BackgroundAn elevated level of cardiac troponin I (cTnI) frequently accompanies an episode of supraventricular tachycardia (SVT). However, the predictive value of cTnI in elderly SVT patients has not been examined. MethodsWe collected the electronic medical records of elderly SVT patients (over 65 years old) who visited four Taiwanese emergency departments over a 2-year period. The patients who underwent cTnI testing were included in the cohort and further categorized based on their cTnI results (positive or negative). The study's primary outcomes were the 5-year risks of major adverse cardiovascular events (MACE) and SVT recurrence. ResultsOne hundred and twenty-four patients met the inclusion criteria. Of these patients, 39 (31.5%) had a positive cTnI result, and 85 (68.5%) had a negative cTnI result. Patients with a positive cTnI result were older (p = 0.029) and had a longer hospital stay (p = 0.023) than those with a negative cTnI result. Multivariate analysis showed that age > 75 years (OR = 2.41; 95% CI 1.07–5.45; p = 0.034) was an independent predictor for cTnI elevation. In the survival analysis, no difference in the incidence of five-year MACE (p = 0.656) was observed between the cTnI-positive and cTnI-negative groups. Multivariate analysis revealed that a history of coronary artery disease was the only significant independent risk factor for MACE (HR = 4.30; 95% 95% CI 1.41–13.05; p = 0.010). For SVT recurrence, the multivariate analysis revealed that previous SVT (HR = 3.37; 95% CI 1.53–7.39; p = 0.002), smoking history (HR = 2.32; 95% CI 1.03–5.24; p = 0.043), and RFA treatment (HR = 0.20; 95% CI 0.06–0.65; p = 0.008) were significant independent predictors. ConclusionsAn increased cardiac troponin level may not effectively indicate the risk of MACE in elderly SVT patients. Physicians might want to be cautious when interpreting troponin test results for this specific patient group.

A rare focal atrial tachycardia arising from the proximal middle cardiac vein: a case report

BackgroundFocal atrial tachycardia (FAT) always originates from atrium specific sites and can be successfully cured by radiofrequency (RF) ablation. However, the middle cardiac vein (MCV) is a rare site of focal atrial tachycardia. Herein, we present a case of a 20-year-old young woman with FAT. Electrophysiological examination showed FAT arising from the proximal middle cardiac vein (pMCV), and successful RF ablation was applied with a low power and short-ablation.Case presentationA 20-year-old woman with no structural heart disease suffered recurrent supraventricular tachycardia for 1 year. Physical examination, laboratory studies and the echocardiography results of this patient were normal. A 12-lead electrocardiogram (ECG) showed a narrow QRS and long RP tachycardia which was always triggered by a sinus rhythm. The patient underwent an electrophysiological study and found the earliest activation was in the proximal MCV (pMCV). After a low power and short-ablation, AT was terminated and noninducible by programmed pacing with or without isoproterenol infusion.ConclusionThis case presented a rare case of FAT arising from the pMCV. We demonstrate that low power and short-ablation are effective in AT arising from specific areas such as the coronary sinus ostium and pMCV.

Cost-utility analysis of radiofrequency ablation versus optimal medical therapy in managing supraventricular tachycardia among Filipinos.

Radiofrequency ablation (RFA) is the standard of care in the management of supraventricular tachycardia (SVT). Its cost-effectiveness in an emerging Asian country has not been studied. A cost-utility analysis of RFA versus optimal medical therapy (OMT) among Filipinos with SVT was conducted using the public healthcare provider's perspective. A simulation cohort using a lifetime Markov model was constructed using patient interviews, a review of literature, and expert consensus. Three basic health states were defined: stable, SVT recurrence, and death. The incremental cost per quality-adjusted life year (ICER) was determined for both arms. Utilities for the entry states were derived from patient interviews using the EQ5D-5L tool; utilities for other health states were taken from publications. Costs were assessed from the healthcare payer perspective. A sensitivity analysis was done. Base case analysis showed that RFA versus OMT is both highly cost-effective at 5 years and over a lifetime. RFA at 5 years costs about PhP276,913.58 (USD5,446) versus OMT of PhP151,550.95 (USD2,981) per patient. Discounted lifetime costs were PhP280,770.32 (USD5,522) for RFA, versus PhP259,549.74 (USD5,105) for OMT. There was improved quality of life with RFA (8.1 vs. 5.7 QALYs per patient). The 5-year and lifetime incremental cost-effectiveness ratios were PhP148,741.40 (USD2,926) and Php15,000 (USD295), respectively. Sensitivity analysis showed 56.7% of simulations for RFA fell below a GDP-benchmarked willingness-to-pay (WTP) threshold. Despite the initial higher cost, RFA versus OMT for SVT is highly cost-effective from the Philippine public health payer's perspective.

Multicenter cohort study on duration of antiarrhythmic medication for supraventricular tachycardia in infants

Antiarrhythmic medication (AM) is commonly used to prevent supraventricular tachycardia (SVT) recurrence in infants. Our aim was to determine whether a shorter duration of AM is sufficient to prevent atrioventricular reentrant tachycardia (AVRT) recurrence and evaluate risk factors for recurrence of SVT after discontinued AM.This multicenter cohort study included all infants diagnosed with SVT in the five university hospitals in Finland between 2005 and 2017. Those diagnosed between 2005 and 2012 received AM for 12 months (group 1), and those diagnosed between 2013 and 2017 received AM for 6 months (group 2). A total of 278 infants presented with AVRT (group 1, n = 181; group 2, n = 97), and the median AM duration was 12.0 months (interquartile range [IQR] 11.4–13.4) and 7.0 months (IQR 6.0–10.2), respectively. Propranolol was the most frequently used first-line AM (92% and 95%). Recurrence-free survival rates were over 88% until 12 months after AM prophylaxis in both groups, without any statistically significant difference between them. Independent risk factors for recurrence of SVT after discontinuation of AM were need of combination AM (HR 2.2, 95% CI 1.14–4.20), Wolff-Parkinson-White (WPW) syndrome (HR 2.4, 95% CI 1.25–4.59), and age over 1 month at admission (HR 2.2, 95% CI 1.12–4.48). Conclusion: Shortening AM duration in infants from 12 to 6 months does not seem to lead to more frequent SVT recurrence. The risk factors for recurrence of SVT were WPW syndrome, need of combination AM, and age over 1 month.What is Known:• Despite the evidence of spontaneous resolution of supraventricular tachycardia episodes in infants, the antiarrhythmic medication is often continued for up to twelve months.• The optimal approach for duration of antiarrhythmic medication remains unknown..What is New:• Shortening the duration of antiarrhythmic medication in infants with supraventricular tachycardia does not seem to increase the risk of subsequent recurrence.• Infants whose arrhythmia was successfully controlled with monotherapy were the group least likely to have recurrence after discontinuation of antiarrhythmic medication.

Narrow QRS complex tachycardia with and without ventriculoatrial block: What is the mechanism?

A 39-year-old woman with no structural heart disease underwent an electrophysiology study (EPS) to assess recurrent supraventricular tachycardia (SVT). The electrocardiogram did not show any preexcitation. The baseline atrio-His and His-ventricular intervals were 108 and 43 ms. Ventricular pacing demonstrated concentric, decremental ventriculoatrial (VA) conduction, and the single jump changed the earliest atrial activation site (EAAS) from the His bundle region to the proximal coronary sinus (CS) region.

Three-dimensional activation maps of sinus rhythm and focal atrial tachycardia in a dog

A five-year-old, female-spayed boxer was referred for frequent and medically refractory paroxysmal supraventricular tachycardia. Diagnostic evaluation found no underlying structural heart or systemic diseases. Three-dimensional electroanatomical mapping and radiofrequency ablation were pursued. Activation mapping of normal sinus rhythm demonstrated the location of the sinus node in the posterolateral region of the right atrium. Activation mapping of the tachyarrhythmia identified a centrifugal activation pattern originating from the right atrium at the posterolateral aspect of the tricuspid valve orifice, suggestive of focal atrial tachycardia. A total of 10 ablation lesions were delivered to the earliest activation site. The dog recovered without complications and no recurrence of supraventricular tachycardia was noted on subsequent follow-ups.

Hypertrophic cardiomyopathy caused by mutations in the &lt;I&gt;PRKAG2&lt;/I&gt; gene

Clinical observations of three cases of hypertrophic cardiomyopathy caused by mutations in the PRKAG2 gene with a debut in early childhood are presented. The sisters whose father suffered from a severe form of hypertrophic cardiomyopathy in combination with Wolf—Parkinson—White syndrome and died at a young age from progressive heart failure are described. Early manifestation of the disease is characteristic, while there was a combination of ventricular preexitation syndrome and myocardial hypertrophy with rapid progression to extreme values. Hypertrophy was concentric symmetrical and biventricular. The main clinical symptom in the first observation was frequent paroxysms of supraventricular tachycardia. New atrioventricular fenestrations were detected during dynamic observation, insufficient effectiveness of radiofrequency ablation, recurrence of supraventricular tachycardia, and a good response to propafenone were noted. The third clinical case is sporadic, a long-term follow-up for 15 years is presented and clearly reflects the progression of the increase in myocardial hypertrophy and cardiac arrhythmias. The disease debuted from an early age in the form of hypertrophy in combination with severe bradycardia, which made drug therapy difficult. Due to the high risk of sudden cardiac death against the background of extreme myocardial hypertrophy, a cardioverter defibrillator was implanted. Signs of mitochondrial insufficiency according to skeletal muscle biopsy are described.

Clinical Predictors of Recurrent Supraventricular Tachycardia in Infancy

BackgroundData regarding recurrence risk among infants with supraventricular tachycardia (SVT) are limited. ObjectivesThe purpose of this study was to determine incidence and factors associated with SVT recurrence. MethodsThis was a retrospective single-center study (1984-2020) with prospective phone follow-up of infants with structurally normal hearts diagnosed at age ≤1 year with re-entrant SVT. Primary outcome was first SVT recurrence after hospital discharge. Classification and regression tree analysis was performed to determine a risk algorithm. ResultsAmong 460 infants (62% male), 87% were diagnosed at ≤60 days of age (median 13 days; IQR: 1-31 days). During a median follow-up of 5.2 years (IQR: 1.8-11.2 years), 33% had recurrence. On multivariable analysis, factors associated with recurrence included: fetal or late (>60 days) diagnosis (HR: 1.90; 95% CI: 1.26-2.86; and HR: 1.73; 95% CI: 1.07-2.77, respectively), Wolff-Parkinson-White (WPW) syndrome (HR: 2.46; 95% CI: 1.75-3.45), and need for multi-antiarrhythmic or second-line therapy (HR: 2.08; 95% CI: 1.45-2.99). Based on the classification and regression tree analysis, WPW incurred the highest risk. Among those without WPW, age at diagnosis was the most important factor predicting risk. Fetal or late diagnosis incurred higher risk, and if multi-antiarrhythmic or second-line therapy was also required, risk nearly doubled. Infants without WPW, who were diagnosed early (0-60 days), and who were discharged on propranolol were at lowest recurrence risk. ConclusionsInfants with SVT are most likely to be diagnosed at ≤60 days and be male. Risk factors for recurrence (occurred in 33%), present at time of diagnosis, include WPW, fetal or late diagnosis, and multi-antiarrhythmic or second-line therapy. Infants with early diagnosis, without WPW, and discharged on first-line monotherapy are at lowest recurrence risk.

Impact of transesophageal electrophysiological study on midterm management of pediatric tachyarrhythmias.

Transesophageal electrophysiological study (TEEPS) is a minimally invasive procedure that helps in evaluating the risk of recurrence of supraventricular tachycardia based on the inducibility of the tachycardia. The purpose of this study was to evaluate the diagnostic capability, negative predictive value of noninducibility of tachycardia and safety of TEEPS among the Indian pediatric population. It is a retrospective single-center observational study of all patients who underwent TEEPS from January 01, 2014, to December 31, 2020. Twenty-two TEEPS procedures were done in eighteen children with three children undergoing more than one procedure. The median duration of follow-up was 42.97 months (8.52-82.12 months). Out of the 22 procedures, four were conducted for acute tachycardia termination, two for tachycardia suppression assessment, and sixteen to assess tachycardia inducibility off medications. Tachycardia was noninducible in nine children and inducible in six children. Two children had clinical recurrence of tachycardia on follow-up. Out of these two children, one had noninducibility of tachycardia on TEEPS. The negative predictive value of TEEPS was 88.89% in this study. None of the children had any postprocedure complication. TEEPS is a safe procedure. It is used to assess the efficacy of medication in the suppression of arrhythmia. The noninducibility of tachycardia has a high negative predictive value and is a good indicator of nonrecurrence of clinical tachycardia on midterm follow-up.

Postnatal recurrence and transesophageal inducibility of prenatally treated fetal supraventricular tachycardia.

Antiarrhythmic treatment of fetal supraventricular tachycardia (SVT) is used to prevent morbidity and mortality. The postnatal management of survivors is often arbitrary and varied. The purpose of this study was to examine the utility of a risk-based postnatal management strategy. Sixty-six prenatally treated newborns with fetal long or short ventriculoatrial tachycardia were reviewed. Postnatal diagnoses included atrioventricular reentrant tachycardia, atrial ectopic tachycardia, and permanent junctional reciprocating tachycardia. Unless SVT persisted to birth, early neonatal observation without treatment was recommended. For newborns without spontaneous arrhythmia after ≥2 days of observation, inducibility was tested by transesophageal pacing study (TEPS). Postnatal therapy was advised for spontaneous or inducible SVT. Characteristics associated with these outcomes were analyzed. Twenty-eight patients (42%) experienced SVT at or early after birth, which was associated with fetal long ventriculoatrial tachycardia (odds ratio [OR] 6.8; 95% confidence interval [CI] 1.88-24.57; P = .0029); delayed in utero cardioversion with treatment (median 11 days vs 5.5 days; P < .0001); prenatal treatment with multiple antiarrhythmics (OR 4.42; 95% CI 1.56-12.55; P = .0059); and postnatal atrial ectopic tachycardia/permanent junctional reciprocating (OR 18.0; 95% CI 2.11-153.9; P = .0013). Of the 38 neonates undergoing TEPS, 19 (50%) had inducible tachyarrhythmias. Recurrence of SVT during infancy or childhood was documented in 4 of 6 patients with SVT at birth (66%), 8 of 22 patients with early neonatal SVT (36%), 4 of 19 patients with inducible SVT (21%), and 0 of 19 untreated patients without inducible SVT (0%) (P= .0032). The postnatal risk of SVT is related to the arrhythmia mechanism and prenatal treatment response. In newborns without spontaneous SVT, TEPS may be useful to guide the need for postnatal treatment on the basis of SVT inducibility.

PO-717-02 TRANS-HEPATIC ‘BODY-FLOSSING’ TO OBTAIN ACCESS IN A PATIENT WITH VENOUS OCCLUSIONS FOR SUPRAVENTRICULAR TACHYCARDIA ABLATION

Trans-hepatic access (THA) can be performed for ablations in patients with femoral venous occlusions. In the setting of additional superior vena cava (SVC) occlusion, obtaining a second access can be challenging. To describe retrograde crossing of a chronic total venous occlusion (CTVO) followed by superior snaring after THA. n/a A 45-year-old female with a history of end-stage renal disease presented with recurrent supraventricular tachycardia refractory to medications. She had dialysis performed at different times via all 4 extremities and had known inferior CTVO. THA was obtained to gain access into the heart (A, blue arrows). Right internal jugular vein (IJV) was occluded; the left IJV vein was accessed, however, there was evidence of SVC stenosis (B, yellow dotted line), and a wire could not be advanced antegradely. Using a Glidewire from the THA, the stenosis was crossed retrogradely (C, yellow arrows). From the left IJV sheath, the wire tip was snared (D, white arrow), and pulled out (Figure 1E, green arrows). Once through-and-through access was obtained, a long sheath was advanced over the wire into the right atrium (F, red arrows) through which another decapolar catheter (G-H, orange arrow) was placed and with the help of the THA decapolar coronary sinus catheter (G, asterisk), the diagnosis of typical atrioventricular node reentrant tachycardia was confirmed. Following this, the THA decapolar catheter was replaced by an ablation catheter (H, red arrow) for successful slow pathway modification. Obtaining venous access in addition to the THA can be challenging in patients with superior and inferior venous stenosis. Retrograde crossing of CTVO scan be performed after THA, and with the help of snaring, additional access can be obtained.