Pulsed-Field Ablation in Management of Ventricular Tachycardia: A Systematic Review of Case Reports and Clinical Outcomes.

BACKGROUND: Pulsed-field ablation (PFA) is a cutting-edge technique that employs non-thermal energy to cause cell death by inducing irreversible electroporation of cell membranes. This systematic review evaluates the PFA effectiveness as a potential alternative to radiofrequency and cryo-ablation for treating ventricular tachycardia. METHODS: PubMed, Embase, Scopus, and Web of Science were systematically searched using keywords related to ventricular tachycardia and pulsed-field ablation. Eligible Studies evaluating this therapeutic approach for ventricular tachycardia were included in the final analysis. RESULTS: We included six studies (five case reports and one case series) in our systematic review. Eight (88.8%) of procedures were successful with 100% long-term efficacy. No procedural complications or ventricular tachycardia (VT) recurrence were observed in the cases. CONCLUSION: The absence of complications, high effectiveness, and long-term success rate make PFAs a good VT treatment option. However, PFA safety and efficacy studies for VT treatment are scarce. Thus, larger investigations on this topic are urgently needed.

Efficacy of Balloon Expandable Extreme-Low Temperature Ventricular Epicardial Cryoablation: A Preclinical Proof of Concept Evaluation.

BACKGROUND: Current epicardial ablation technologies are limited by the inability to create adequate depth lesions and risk of collateral injury to extracardiac structures. OBJECTIVE: To evaluate the feasibility and efficacy of ventricular epicardial ablation with a novel balloon-expandable extreme-low temperature (XLT) cryoablation catheter with an embedded insulation pontoon for protection of extracardiac structures which has been specifically designed for epicardial ablation. METHODS: 10 healthy swine underwent surgical (6) and subxiphoid percutaneous (4) epicardial access respectively. A total of 3-6 sites were targeted in the right and left ventricular wall for different exposure durations. Ablation was performed with a large footprint (surgical) and smaller footprint (percutaneous) version of the HeartPad® (Corfigo Inc., Montclair, NJ) XLT system. The system consists of the balloon-expandable cryoablation catheter and a console. The console vaporizes liquid helium (-269˚C) and controls continuous delivery of extremely cold helium gas at high flow rates through a high-efficiency ablation element mounted on an expandable insulation pontoon to protect extracardiac structures. Ablation lesions were assessed by gross pathology and histological examination. RESULTS: A total of 42 epicardial lesions were created. The mean lesion depth increased progressively with the ablation time (surgical catheter: 11±2 mm at ≤30 seconds, 13±4 mm at 60 seconds, 15±3 mm at ≥120 seconds, P =0.001; percutaneous catheter: 10±2 mm at 30 seconds, 14±2 mm at 60 seconds, 16±2 mm at 120 seconds], P =0.001). Lesion geometry appeared unaffected by presence and thickness of epicardial fat. One episode of ventricular fibrillation occurred following ablation over the atrioventricular groove and 2 adjacent obtuse marginal arteries. CONCLUSION: Surgical or percutaneous epicardial ablation using the HeartPad® XLT cryoablation system is feasible and can efficiently produce deep ventricular lesions in different epicardial locations.

Extended Ambulatory ECG Monitoring Enhances Identification of Higher-Risk Ventricular Tachyarrhythmias in Patients with Hypertrophic Cardiomyopathy.

BACKGROUND: In hypertrophic cardiomyopathy (HCM), 48-hour ambulatory monitoring has been standard practice to detect nonsustained ventricular tachycardia (NSVT), a sudden death risk marker. Extended wear ambulatory ECG devices have more recently utilized for monitoring HCM patients. OBJECTIVE: Evaluate NSVT burden identified with continuous ambulatory monitoring for up to 2 weeks compared to initial 48 hours. METHODS: 236 consecutive HCM patients (49 ± 12 years) underwent 14-day continuous ambulatory monitoring (Zio XT, iRhythm Technologies); diagnostic yield of NSVT compared for initial 48 hours vs. extended for 14 days. RESULTS: Of 236 patients, 114 (48%) had ≥1 runs of NSVT (median 2) over 14 days. Median length of NSVT was 7 beats (range: 3 to 67) at rates of 120 to 240 bpm (median, 167 bpm). In 42 of the 114 patients (37%), initial NSVT occurred ≤ 48 hours and in 72 (63%) only during the extended monitoring period (3 to 14 days). Diagnostic yield for detecting NSVT over 14 days was 2.7-fold greater than ≤ 48 hours (p<0.001). NSVT judged at higher risk (≥8 beats, >200 bpm, ≥2 runs in consecutive 2-day period) was identified more frequently during extended monitoring, diagnostic yield 3.0-fold greater than ≤ 48 hours (p<0.001). CONCLUSION: In HCM, NSVT episodes are frequent, however, in most patients, both NSVT and higher risk NSVT were not detected during initial 48-hours and confined solely to extended monitoring period. These data support additional clinical studies to evaluate the significance of NSVT on extended monitoring on sudden death risk in HCM.

Spontaneous termination of ventricular tachycardia in the human heart.

INTRODUCTION: Understanding the spatiotemporal location of the spontaneous termination of ventricular tachycardia (VT) may provide new insights for ablation. To test the hypothesis that spontaneous VT termination most frequently occurs at the VT exit due to source-sink mismatch and to characterize electrophysiological properties of the sites termination during VT and with extra-stimulus technique. METHODS: Retrospective analysis of intraoperative mapping studies of nine patients with ischemic cardiopathy or repaired tetralogy of Fallot. Simultaneous endocardial and epicardial mapping was performed in both ventricles using a custom mapping array during VT. Electrogram (EGM) characteristics before and at the moment of termination were analyzed including: cycle length oscillations, EGM heterogeneity and a variation in the systolic/diastolic path. The decrements to extra stimulus were analysed for termination sites and other diastolic sites. RESULTS: Nine VTs in seven patients demonstrated spontaneous VT termination. Seven VTs (77.8%) spontaneously terminated in the final third of the systolic interval, one (11.1%) in early diastole and one (11.1%) in mid diastole. Cycle length oscillations (prolongation, shortening, and no change) were seen in equal frequency. Four VTs (44.4%) showed alternans in the local EGM at the site of termination and this was more prevalent than alternans at other sites in the diastolic pathway (p < .001). Only one-third of VTs showed a change in activation pattern before termination. There was no difference based on etiology. During substrate characterization with extra-stimulus pacing, sites of spontaneous termination showed greater decrement than other sites of the VT circuit during pacing (43.5 ± 14.5 ms vs. 31.2 ± 31.2 ms; p = .003). CONCLUSION: The entrance zone rather than the exit is the commonest site for the spontaneous termination of VT in the human heart. These sites tend to demonstrate EGM alternans during VT and greater decrement during extrastimulus pacing. These findings may help guide future studies into improving the success of VT ablation.

Implementing stereotactic arrhythmia radioablation with STOPSTORM.eu consortium support: intermediate results of a prospective Israeli single-institutional trial.

BACKGROUND: Ventricular tachycardia (VT) is a life-threatening arrhythmia originating from the heart's ventricles. Traditional treatments include antiarrhythmic medications, implantable cardioverter-defibrillators (ICDs), and catheter ablation. Stereotactic body radiation therapy (SBRT) targeting the arrhythmogenic focus in the left ventricle-stereotactic arrhythmia radioablation (STAR)-is an emerging treatment and may offer a potential solution for patients with refractory VT. OBJECTIVE: We designed an interventional prospective clinical trial in Israel aligned with the STOPSTORM.eu consortium's benchmarks, recommendations, and directives to assess the safety and efficacy of STAR in patients with refractory VT. METHODS: Our phase I/II single-institutional trial was approved by the Ministry of Health of Israel for 10 patients, initially assessing safety in the first 3 patients. We included patients with ICDs experiencing symptomatic monomorphic VT after an inadequate response to previous therapies. The primary endpoints were treatment-related serious adverse events and a reduction in VT burden as assessed by ICD interrogation. Secondary outcomes included a reduction in antiarrhythmic medications and changes in quality of life. RESULTS: From August 2023 to August 2024, 3 patients underwent STAR treatment. The prescription dose was a single fraction of 25 Gy. Planning target volumes were 47.8, 49.7, and 91.8 cc, and treatment was successfully delivered with no grade 3 or higher adverse events reported. Over a follow-up period of 12 months for the first patient and 8 months for the second one, no VT events were recorded after treatment. The third patient died from progressive heart failure 3 months after treatment. Left ventricular ejection fraction remained stable, and no significant radiation-induced inflammatory changes were noted. CONCLUSION: The initial results of this trial suggest that STAR can reduce VT episodes in patients with refractory VT without severe adverse effects. The study highlights the importance of international collaboration and standardization in pioneering new treatments. Further follow-up and additional patient data will be necessary to confirm these findings and evaluate long-term outcomes, including potential adjustments to antiarrhythmic medication regimens.

[The challenging patient-recommendations and solutions]. / Der schwierige Patient − Tipps und Tricks.

BACKGROUND: The continuous technical development of cardiac computed tomography (CT) over the last decades has led to an improvement in image quality and diagnostic accuracy, while simultaneously reducing radiation exposure. Despite these advancements, certain patient-related factors remain a challenge to conduct a high-quality diagnostic examination. QUESTION: What factors can negatively affect the image quality of cardiac CT and how can these be addressed? MATERIALS AND METHODS: Analysis of the available literature on cardiac CT and identification of the quality-limiting factors, discussion, and possible solutions. RESULTS: Tachycardia, arrhythmias, high coronary calcification, the presence of stents and coronary artery bypasses, as well as obesity and anxiety were identified as primary factors that limit image quality and diagnostic accuracy. These issues primarily arise from a lack of response or the presence of contraindications to premedication, blooming artifacts, variations in postoperative anatomy, as well as other personal factors. Suggested solutions include optimizing premedication, scanner modifications, the selection of the most suitable acquisition mode, new scanner technologies, and innovative image reconstruction methods including artificial intelligence. CONCLUSIONS: Certain factors continue to pose a major challenge for cardiac CT. Knowledge of alternative premedication, scanner modifications, as well as the use of postprocessing software and new technologies can help overcome these limitations, enabling successful and safe cardiac CTs even in challenging patients.

Enhancing risk assessment in Chagas cardiomyopathy: Electrophysiology study stratified by Rassi score.

BACKGROUND: Chagas cardiomyopathy (CCM) is increasingly prevalent in developed countries due to migration from endemic areas. Accurate risk stratification is crucial due to the variable clinical course of CCM. OBJECTIVE: To analyze the association between Rassi score progression and electrophysiology study (EPS) changes in CCM patients. METHODS: This prospective, observational cohort study involved CCM patients from two tertiary hospitals. Patients were classified as low, intermediate, or high risk based on the Rassi score. Data collected included demographics, clinical history, and diagnostic tests. EPS assessed AH, HH, and HV intervals, and inducibility of ventricular arrhythmias. Follow-ups were at 30 days and six-month intervals, with individualized discussions for cardiac implantable electric devices (CIED) based on EPS results. RESULTS: Of 67 screened CCM patients, 59 underwent EPS. The mean Rassi score was 8.7 ± 4.5 points, with 33.8 % low, 38.9 % intermediate, and 27.1 % high risk. EPS abnormalities were found in 57.6 % of patients, mainly VT/VF (52.5 %). Most induced ventricular arrhythmias were monomorphic VT (80.7 %). A significant association was found between Rassi score risk classification and EPS changes (OR = 1.88 95 %CI: 1.15-3.06 p = 0.02). Higher Rassi scores correlated with VT presence on EPS (p = 0.0036). Syncope/pre-syncope had an OR 2.45 95 %CI:1.21-4.94; p = 0.012, independent of Rassi risk. Decreased ejection fraction was linked to EPS changes (p = 0.04). CONCLUSION: EPS changes among CCM was associated with progression of the Rassi score, indicating its utility as a stratification tool. Factors such as the presence of syncope/pre-syncope, decreased LVEF and wall motion abnormalities emerged as independent predictors within Rassi scores for changes in EPS.

Landiolol for heart rate control in patients with septic shock and persistent tachycardia. A multicenter randomized clinical trial (Landi-SEP).

PURPOSE: Excessive tachycardia in resuscitated septic shock patients can impair hemodynamics and worsen patient outcome. We investigated whether heart rate (HR) control can be achieved without increased vasopressor requirements using the titratable highly selective, ultra-short-acting ß1-blocker landiolol. METHODS: This randomized, open-label, controlled trial was conducted at 20 sites in 7 European countries from 2018 to 2022 and investigated the efficacy and safety of landiolol in adult patients with septic shock and persistent tachycardia. Patients were randomly assigned to receive either landiolol along with standard treatment (n = 99) or standard treatment alone (n = 101). The combined primary endpoint was HR response (i.e., HR within the range of 80-94 beats per minute) and its maintenance without increasing vasopressor requirements during the first 24 h after treatment start. Key secondary endpoints were 28-day mortality and adverse events. RESULTS: Out of 196 included septic shock patients, 98 received standard treatment combined with landiolol and 98 standard treatment alone. A significantly larger proportion of patients met the combined primary endpoint in the landiolol group than in the control group (39.8% [39/98] vs. 23.5% [23/98]), with a between-group difference of 16.5% (95% confidence interval [CI]: 3.4-28.8%; p = 0.013). There were no statistically significant differences between study groups in tested secondary outcomes and adverse events. CONCLUSION: The ultra-short-acting beta-blocker landiolol was effective in reducing and maintaining HR without increasing vasopressor requirements after 24 h in patients with septic shock and persistent tachycardia. There were no differences in adverse events and clinical outcomes such as 28-day mortality vs. standard of care. The results of this study, in the context of previous trials, do not support a treatment strategy of stringent HR reduction (< 95 bpm) in an unselected septic shock population with persistent tachycardia. Further investigations are needed to identify septic shock patient phenotypes that benefit clinically from HR control.

Long COVID and hypermobility spectrum disorders have shared pathophysiology.

Hypermobility spectrum disorders (HSD) and hypermobile Ehlers-Danlos syndrome (hEDS) are the most common joint hypermobility conditions encountered by physicians, with hypermobile and classical EDS accounting for >90% of all cases. Hypermobility has been detected in up to 30-57% of patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), fibromyalgia, postural orthostatic tachycardia syndrome (POTS), and long COVID (LC) compared to the general population. Extrapulmonary symptoms, including musculoskeletal pain, dysautonomia disorders, cognitive disorders, and fatigue, are seen in both LC and HSD. Additionally, ME/CFS has overlapping symptoms with those seen in HSD. Mast cell activation and degranulation occurring in both LC and ME/CFS may result in hyperinflammation and damage to connective tissue in these patients, thereby inducing hypermobility. Persistent inflammation may result in the development or worsening of HSD. Hence, screening for hypermobility and other related conditions including fibromyalgia, POTS, ME/CFS, chronic pain conditions, joint pain, and myalgia is essential for individuals experiencing LC. Pharmacological treatments should be symptom-focused and geared to a patient's presentation. Paced exercise, massage, yoga, and meditation may also provide benefits.

Doxophylline With Paroxysmal Supraventricular Tachycardia: A Case Report.

Purpose: We report a case of a patient experiencing paroxysmal supraventricular tachycardia after infusing doxophylline. Methods: Clinical evaluations and the electrocardiogram were performed by specialists. Findings: Our patient felt palpitations and chest distress after intravenous Doxophylline. The electrocardiogram showed paroxysmal supraventricular tachycardia. There was no evidence to prove that there was any problem with his heart, liver, and kidney. According to the Naranjo Adverse Drug Reaction probability scale, paroxysmal supraventricular tachycardia has a probable relationship with Doxophylline. Implications: The paroxysmal supraventricular tachycardia is a rare but reasonable adverse reaction of Doxophylline, which should be paid more attention.

Rare electrocardiographic findings in a young woman with acute barium poisoning: A case report.

Background: Barium, as a heavy divalent alkaline earth metal, can be found in various products such as rodenticides, insecticides, depilatories, and fireworks. Barium can be highly toxic upon both acute and chronic exposure. The toxicity of barium compounds is dependent on their solubility. Both suicidal and accidental exposures to soluble barium can cause toxicity. Case summary: We report a case characterized by two different wide QRS complex tachycardia in a patient with acute barium poisoning, one due to barium-induced ventricular tachycardia (VT) under hypokalemia and, subsequently, sino-ventricular conduction with intraventricular conduction delay due to hyperkalemia after aggressive potassium supplementation. The latter may be misdiagnosed as VT for the history of acute barium poisoning and the absence of peaked T wave in hyperkalemia. Of note, another hemodynamically unstable VT and profound hypokalemia occurred during the potassium-lowering therapy, which, in addition to barium poisoning, may also be due to the iatrogenic hypokalemia. We also observed the prominent T-U waves at serum potassium of 4.6 mM 12 hours after admission, which may indicate that barium had not been completely cleared from the plasma at that moment. There are some parallels to the Andersen-Tawil syndrome with prominent T-U waves and risk of ventricular tachycardias. To our knowledge, this is the first case report of conversion from hypokalemia to hyperkalemia, and in a short moment, from hyperkalemia to hypokalemia, in acute barium poisoning. Conclusion: In addition to profound hypokalemia secondary to acute barium poisoning, hyperkalemia may also occur after aggressive potassium supplementation. A more careful rather than too aggressive potassium supplementation may be suitable in these cases of hypokalemia due to an intracellular shift of potassium. And a iatrogenic hypokalemia risk in the treatment of rebound hyperkalemia in barium poisoning must be considered.

Complication Avoidance in Chiari Malformation Surgery.

Posterior fossa decompression for symptomatic Chiari malformation is an effective and frequently performed procedure, but it does carry risks of significant complications including cerebrospinal fluid leak and craniocervical instability. Patients sometimes do not improve or worsen after decompression, which may discourage neurosurgeons from performing Chiari decompression surgery. In this chapter, management strategies and surgical approaches are discussed that minimize the risks of complications and maximize favorable outcomes in Chiari malformation surgery.

Assessing the Risks and Benefits of Hypotensive Anesthesia and Piezosurgical Instruments in Bimaxillary Surgery.

The challenge in bimaxillary surgery lies in significant intraoperative bleeding, prompting various strategies to minimize blood loss. Among the methods considered for controlling intraoperative bleeding, hypotensive anesthesia and the use of piezosurgical instruments (Osada, Tokyo, Japan) have been explored. However, hypotensive anesthesia may have adverse effects on cardiac function, and surgical time is likely to be prolonged when using piezosurgical instruments. This study retrospectively examined whether the combined use of hypotensive anesthesia and piezosurgical instruments reduces intraoperative bleeding and whether the combination impacts cardiac function. The combination of hypotensive anesthesia and piezosurgical instruments significantly reduced intraoperative bleeding. Furthermore, the combination was associated with a significantly higher incidence of tachycardia, particularly with the use of nicardipine. Additionally, the combination significantly lengthened the duration of the surgery and may have increased the burden on cardiac function. Landiolol was effectively employed to manage tachycardia. When selecting hypotensive anesthesia as a means to limit bleeding, proactive preparation and preventive small-dose administration of landiolol could be beneficial in managing the potential occurrence of tachycardia.

Calcium channel blockers and beta blockers in pediatric supraventricular tachycardia.

INTRODUCTION: Supraventricular tachycardia (SVT) is a common pediatric arrhythmia. Beta blockers (BBs) and calcium channel blockers (CCBs) are used for treatment despite little data examining their use. We describe the prescriptive tendencies, efficacy, and tolerability of BBs and CCBs used in the treatment of pediatric SVT. METHODS AND RESULTS: This is a multicenter retrospective cohort study from three academic children's hospitals. Individuals aged 1-21 years at time of SVT diagnosis initiated on a BB or a CCB between 01/01/2010 and 12/31/2020 were included. Exclusion criteria were pre-excitation, ectopic atrial tachycardia, and hemodynamically significant heart disease. Demographic, comorbidity, symptomatology, and medication data were collected. Treatment success was defined using a composite data abstraction tool. Of 164 patients, 151 received a BB and 13 received a CCB. The success rate on the initial dosage was 46% for both BB and CCB; the success rate following dosage adjustments was also comparable for BBs (98/151, 65%) and CCBs (9/13, 69%). While 27 (18%) BB patients experienced intolerable side effects, no CCB patient did. CONCLUSION: Treatment with a BB or CCB was successful in half of patients. BBs were prescribed more frequently than CCBs but were associated with more side effects.

Ketamine Terminating Persistent Ventricular Tachycardia.

Ventricular tachycardia (VT) is an arrhythmia associated with sudden cardiac death. VT storm is a complication of persistent VT requiring immediate antiarrhythmic therapy. In refractory cases, adjunctive therapy includes sedation/mechanical ventilation or catheter ablation. This case highlights a patient with ischemic cardiomyopathy in refractory VT storm terminated by administration of ketamine.

Incessant Ventricular Tachycardia: An Atypical Presentation of Chronic Eosinophilic Leukemia.

Hypereosinophilic syndrome comprises a diverse and intricate array of rare disorders, exhibiting clinical manifestations that extend across various medical subspecialties. Within its myeloid form, chronic eosinophilic leukemia represents a rare myeloid malignancy characterized by severe hematological complications and distinctive organ dysfunction, notably affecting the cardiovascular system. This report presents a rare case of chronic eosinophilic leukemia and Loeffler syndrome with an initial presentation of ventricular tachycardia.

Bipolar Ablation From the Anterior Interventricular Vein to the Left Ventricle.

Ventricular tachycardia from the left ventricular summit can be challenging for catheter ablation due to difficult accessibility and proximity to coronary arteries. This paper presents a case of premature ventricular contraction-induced ventricular tachycardia from the left ventricular summit that was ablated using bipolar radiofrequency ablation from the anterior interventricular vein and adjacent left ventricular endocardium.