Refractory svt

BACKGROUND: Atrioventricular (AV) reentrant tachycardia is a common type of supraventricular tachycardia (SVT) that occurs in the fetus and neonate. Although many tachycardias resolve within several weeks of birth or respond to medical management, disruptions in the cardiac annulus fibrosus and development of additional accessory pathways may lead to refractory dysrhythmia resulting in fetal hydrops and ultimately, fetal death. OBJECTIVES: While accessory pathways have been well documented anatomically in adult and childhood tachyarrhythmias, there are no reports of the histology of these pathways in human fetuses with SVT...

Background : Focal atrial tachycardia (AT) originating from the right atrial appendage (RAA), often persistent and refractory, is clinically rare in pregnant woman, and the therapy is much more challenging. We report that a pregnant woman presented with hypotension due to persistent and refractory atrial tachycardia and was successfully cured by a multidisciplinary treatment (MDT) approach, consisting of a combination of zero-fluoroscopy mapping and thoracoscopic atrial appendectomy. We also carried out a literature review of this topic...

The well-defined concept of aberrant ventricular conduction was introduced over 100 years ago and, despite advances in cardiac physiology and electrophysiologic testing, it is still widely misunderstood. Aberrant ventricular conduction is due to physiologic refractoriness of the His-Purkinje system and in most cases does not reflect underlying conduction system disease. Electrophysiologically, aberrant ventricular conduction can manifest with premature atrial ectopics, the Ashman phenomenon with atrial tachyarrhythmias, concealed conduction, echo beats and with the sinus mechanism including rate dependent bundle branch block, bradycardia dependent bundle branch block and early sinus beats...

BACKGROUND: Supraventricular tachycardia poses a clinical challenge during pregnancy, particularly if refractory to antiarrhythmic medications. Performing catheter ablation during pregnancy necessitates careful risk benefit analysis for both the mother and foetus, especially with left-sided ablations that may require post-procedural systemic anticoagulation. CASE SUMMARY: We describe a case of a 31-year-old pregnant woman with refractory atrial tachycardia which failed a multi-antiarrhythmic drug regimen and ultimately developed abruptio placentae, requiring a carefully staged ablation approach for definitive treatment...

BACKGROUND: Alpha lipoic acid (ALA) is an anti-oxidant found in many over-the-counter supplements and is used in treatments for diabetes, hypertension, and obesity. Although it is a safe oral molecule, there have been eight cases of ALA toxicity reported. Three reported cases were among adult patients and five were among pediatric patients. A 14-year-old girl died after ingestion of 6 g of ALA leading to multi-organ failure. CASE REPORT: A 42-year-old woman presented to the emergency department 4 h after an intentional overdose of 10 tablets of ALA 600 mg each (6 g, 92...

INTRODUCTION: Refractory arrhythmias during pregnancy pose challenges to physicians. AIM: To give an overview of catheter ablation for tachyarrhythmias during pregnancy, and to discuss the indications of the procedure and the outcomes of both mother and fetus. MATERIAL AND METHODS: The study materials were based on comprehensive literature retrieval of the pertinent articles published since 2000. RESULTS: The indications for catheter ablation were refractory arrhythmias unresponsive to drug therapy in most of the cases followed by requirement of cardioversion...

BACKGROUND: Long-term data helps assess the consistency of efficacy, tolerability, and safety of acute treatment over repeated use for different attacks. Real-world studies help assess tolerability, safety, and efficacy in patients with possibly refractory chronic migraine, more comorbidities, other diseases such as cardiovascular diseases, and polypharmacy. METHODS: This is a narrative review of the long-term open-label and real-world studies of lasmiditan, ubrogepant, and rimegepant for the acute treatment of migraine...

Tachycardia-induced cardiomyopathy (T-CMP) related to supraventricular arrhythmia is a rare and often unrecognized cause of refractory cardiogenic shock. When rhythm control interventions are ineffective or no longer pursued, atrioventricular node ablation (AVNA) with pacemaker implantation is indicated. Conduction system pacing provides normal synchronous activation of the ventricles after AVNA. However, there is a lack of data on pace and ablate strategy in hemodynamically unstable patients. We report on 2 patients with T-CMP presenting with refractory cardiogenic shock who were successfully treated with His bundle pacing in conjunction with AVNA...

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...

We present a case of adult-onset Still's disease, a rare disease that presented with a rare complication, myocarditis. After initial therapy with prednisolone 1 mg/kg/day, the patient experienced dyspnea due to severe pleural effusion and palpitations on account of new-onset supraventricular tachycardia. Therapy with three consecutive pulses of 1000 mg of methylprednisolone and anakinra 100 mg/day proved to be effective, with a progressive resolution of all symptoms. However, at three months follow-up, oligoarthritis recurred along with high serum ferritin...

Fetal supraventricular tachycardia can be difficult to manage and offers a challenging treatment course, particularly in refractory cases. The treatment course must balance maternal well-being with the health status of the fetus, all while racing against possible progression to hydrops fetalis or permanent cardiac dysfunction. We describe a case of fetal supraventricular tachycardia that demonstrates many of these concepts, as well as the importance of utilizing several treatment pathways in refractory cases...

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The delivery of ventricular extra-stimulus when the His bundle is refractory is the most important maneuver in the diagnosis of an accessory pathway conduction.The "reset" indicates that the extra-stimulus has penetrated the circuit to alter the "subsequent cycle'. The advanced atrial activation time is expected to affect (reset or terminate) the tachycardia to the next cycle. However, some pitfalls should be kept in mind in the evaluation of the resetting response. This article is protected by copyright. All rights reserved...

We present the case of a healthy 12-year-old boy without structural heart disease who was followed for several years for an arrhythmia with diverse and incorrect initial diagnoses, refractory to flecainide, metoprolol and verapamil. Thorough reevaluation of the electrocardiographic recordings led to a presumptive diagnosis of a non-reentrant atrioventricular nodal tachycardia, subsequently confirmed with electrophysiology study. Radiofrequency ablation was performed during the procedure and the arrhythmia resolved...

Atrial fibrillation (AF) is an irregular heart rhythm, characterised by chaotic atrial activation, which is promoted by remodelling. Once initiated, AF can also propagate the progression of itself in the so-called ''AF begets AF''. Several lines of investigation have shown that signalling molecules, including reactive oxygen species, angiotensin II, and phosphoinositide 3-kinases (PI3Ks), in presence or absence of cardiovascular disease risk factors, stabilise and promote AF maintenance. In particular, reduced cardiac-specific PI3K activity that is not associated with oncology is cardiotoxic and increases susceptibility to AF...

BACKGROUND: Specific pacing methods to unmask the existence of the dual atrioventricular (AV) nodal pathway in patients with dual AV nodal non-reentrant tachycardia remain to be established. OBJECTIVE: This study aimed to determine the electrophysiological characteristics of dual AV nodal non-reentrant tachycardia by its responses to specific pacing methods. METHODS: Five patients diagnosed as having dual AV nodal non-reentrant tachycardia were retrospectively investigated...

BACKGROUND: His-refractory premature ventricular complexes perturbing a supraventricular tachycardia (SVT) establish the presence of an accessory pathway (AP). Earlier premature ventricular complexes (ErPVCs) may perturb SVTs but are considered nondiagnostic. OBJECTIVE: The purpose of this study was to test the hypothesis that an ErPVC will always show a difference >35 ms in its advancement of the next atrial activation during atrioventricular nodal reentrant tachycardia (AVNRT)...

BACKGROUND: Although orthodromic atrioventricular reentrant tachycardia (AVRT) using retrograde conduction through an accessory pathway (AP) is a common manifestation of Wolff-Parkinson-White (WPW) syndrome, a rare yet critical consequence is sudden cardiac arrest in a few patients. This fatal event used to be reported as a result of rapid atrioventricular conduction of atrial fibrillation via an AP. CASE SUMMARY: A 3-month-old infant with WPW syndrome had AVRT accompanied by global cardiac ischaemia, apparently caused by a rapid ventricular rate itself that degenerated into ventricular fibrillation during the AVRT...

BACKGROUND: Phase I KAT301 trial investigated the use of intramyocardial adenoviral vascular endothelial growth factor -DΔNΔC (AdVEGF-D) gene therapy (GT) to alleviate symptoms in refractory angina (RA) patients. In KAT301, 30 patients with RA were randomized to AdVEGF-D or control group in 4:1 ratio. The treatment was found feasible, increased myocardial perfusion, and reduced angina symptoms at 1-year follow-up. However, there is some evidence suggesting that intramyocardial delivery route and overexpression of VEGFs might induce ventricular arrhythmias...

Tachyarrhythmias are common complications of critically ill patients treated on intensive care units. Landiolol is an ultra-short acting beta-blocker with a very high beta1-selectivity. Therefore, landiolol effectively reduces heart rate with only minimal negative effects on blood pressure and inotropy. This article describes two cases of successful treatment of supraventricular and ventricular tachycardias with landiolol in critically ill patients.