Combined modified Valsalva maneuver with adenosine supraventricular tachycardia: A comparative study.

BACKGROUND AND IMPORTANCE: Paroxysmal supraventricular tachycardia (PSVT) is an arrhythmia commonly seen in the emergency department. Both modified Valsalva maneuver (MVM) and intravenous adenosine are the first line treatment, of which the former has e lower success rate while the latter has a higher success rate but some risks and adverse effects. Given both of these reverse rhythms quickly, combining them may achieve a better effect. OBJECTIVE: The objective of this study is to evaluate the success rate and potential risk of combining the use of intravenous adenosine while patients were doing MVM as a treatment for paroxysmal supraventricular tachycardia(pSVT). DESIGN, SETTINGS AND PARTICIPANTS: We recruited patients with pSVT from 2017 to 2022, and randomly assigned them into 3 groups, MVM group, intravenous adenosine group, and combination therapy group, in which MVM was allowed to be performed twice, while intravenous adenosine was given in a titration manner to repeat three times, recorded the success rate and side effects in each group. MAIN RESULTS: The success rate of the MVM group, adenosine group, and combination group are 42.11%, 75.00 and 86.11%, respectively. The success rate of the adenosine group and combination group is significantly higher than the n MVSM group (p < 0.01, p < 0.001), while the success rate of the combination group is higher than the adenosine group, it has no significant difference (p = 0.340). In terms of safety, the longest RR durations (asystole period) are 1.61 s, 1.60s, and 2.27 s, there is a statistical difference among the three groups (p < 0.01) and between the adenosine and combination group (0.018). CONCLUSION: Therefore, we can conclude that combination therapy has a relatively high success rate and good safety profile, but the current study failed to show its superiority to adenosine.

Sotalol in neonates for arrhythmias: Dosing, safety, and efficacy.

INTRODUCTION: Various agents may be utilized to manage supraventricular tachycardia (SVT) in neonates and infants. Recently, sotalol has piqued interest given its reported success in managing neonates and infants with SVTs, especially with the intravenous formulation. While the manufacturer recommends using an age-related nomogram in neonates and young infants to guide doses, clinical reports describe various dosing based on weight (mg/kg) or on body surface area (BSA) in mg/m2 . Given the reported variation in clinical practice with regard to dosing in neonates, there is a gap in the literature and translation into clinical practice regarding applicability of the nomogram into clinical practice. The purpose of this study was to describe sotalol doses based on body weight and BSA in neonates for SVT. METHODS: This is a single center retrospective study evaluating effective sotalol dosing from January 2011 and June 2021 (inclusive). Neonates who received intravenous (IV) or oral (PO) sotalol for SVT were eligible for inclusion. The primary outcome was to describe sotalol doses based on body weight and BSA. Secondary outcomes include comparison of doses to the manufacturer nomogram, description of dose titrations, reported adverse outcomes, and change in therapy. Two-sided Wilcoxon signed-rank tests were used to determine statistically significant differences. RESULTS: Thirty-one eligible patients were included in this study. The median (range) age and weight were 16.5 (1-28) days and 3.2 (1.8-4.9) kg, respectively. The median initial dose was 7.3 (1.9-10.8) mg/kg or 114.3 (30.9-166.7) mg/m2 /day. Fourteen (45.2%) of patients required a dose increase for SVT control. The median dose required for rhythm control was 8.5 (2-14.8) mg/kg/day or 120.7 (30.9-225) mg/m2 /day. Of note, the median recommended dose per manufacturer nomogram for our patients would have been 51.3 (16.2-73.8) mg/m2 /day, which is significantly lower than both the initial dose (p < .001) and final doses (p < .001) utilized in our study. A total of 7 (22.9%) patients were uncontrolled on sotalol monotherapy using our dosing regimen. Two patients (6.5%) had reports of hypotension and one patient (3.3%) had a report of bradycardia requiring discontinuation of therapy. The average change in baseline QTC following sotalol initiation was 6.8%. Twenty-seven (87.1%), 3 (9.7%), 1 (3.3%) experienced prolongation, no change, or a decrease in QTc, respectively. CONCLUSIONS: This study demonstrates that a sotalol strategy significantly higher than the manufacture dose recommendations are required for rhythm control in neonates with SVT. There were few adverse events reported with this dosing. Further prospective studies would be advantageous to confirm these findings.

Medical cardioversion of atrial fibrillation and flutter with class IC antiarrhythmic drugs in young patients with and without congenital heart disease.

INTRODUCTION: The use of flecainide and propafenone for medical cardioversion of atrial fibrillation (AF) and atrial flutter/intra-atrial reentrant tachycardia (IART) is well-described in adults without congenital heart disease (CHD). Data are sparse regarding their use for the same purpose in adults with CHD and in adolescent patients with anatomically normal hearts and we sought to describe the use of class IC drugs in this population and identify factors associated with decreased likelihood of success. METHODS: Single center retrospective cohort study of patients who received oral flecainide or propafenone for medical cardioversion of AF or IART from 2000 to 2022. The unit of analysis was each episode of AF/IART. We performed a time-to-sinus rhythm analysis using a Cox proportional hazards model clustering on the patient to identify factors associated with increased likelihood of success. RESULTS: We identified 45 episodes involving 41 patients. As only episodes of AF were successfully cardioverted with medical therapy, episodes of IART were excluded from our analyses. Use of flecainide was the only factor associated with increased likelihood of success. There was a statistically insignificant trend toward decreased likelihood of success in patients with CHD. CONCLUSIONS: Flecainide was more effective than propafenone. We did not detect a difference in rate of conversion to sinus rhythm between patients with and without CHD and were likely underpowered to do so, however, there was a trend toward decreased likelihood of success in patients with CHD. That said, medical therapy was effective in >50% of patients with CHD with AF.

A Galvanizing Solution: Colonoscopy Bowel Preparation as a Trigger for Supraventricular Tachycardia.

BACKGROUND: Polyethylene glycol (PEG)-based solutions are among the most commonly used bowel preparation regimens for colonoscopy. Although these solutions are well tolerated, rare adverse cardiac events have been reported. OBJECTIVES: We sought to identify the characteristics that may predispose patients to develop supraventricular tachycardia (SVT) after ingestion of GoLYTELY (PEG 3350 and electrolytes oral solution) in anticipation for their colonoscopy. METHODS: We performed a retrospective observational cohort study of the electronic medical record of all patients who developed SVT after ingestion of GoLYTELY solution from April 2012 to March 2019 at the John D. Dingell VA Medical Center. Clinical data were obtained through review of medical records. RESULTS: We identified 16 patients with new-onset SVT after ingestion of bowel preparation solution before undergoing the colonoscopy procedure. In all, 12 (75%) patients developed atrial fibrillation, 3 (18.8%) patients developed atrial tachycardia, and 1 patient (6.3%) developed atrial flutter. Most patients were male (93.8%), and the mean age was 69 ± 8.2 years. The commonly associated comorbidities were hypertension (87.5%), hyperlipidemia (56.3%), and diabetes (37.5%). Laboratory testing demonstrated a normal electrolyte panel and thyroid stimulating hormone level. A significant percentage of patients had dilated atria and left-ventricular hypertrophy on echocardiogram. CONCLUSION: Our case series suggests that there may be certain individuals who are predisposed to development of atrial arrhythmias, more so than others, after ingestion of PEG based solution for colonoscopy. We hypothesize that the combination of atrial dilation, sympathovagal discharge, and transient electrolyte shifts at the cellular level led to the development of SVTs.

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.

Opioid, gabapentinoid, and nonsteroidal anti-inflammatory medication use and the risks of atrial fibrillation and supraventricular ectopy in the Multi-Ethnic Study of Atherosclerosis.

PURPOSE: Opioids, gabapentinoids, and nonsteroidal anti-inflammatory drugs (NSAIDs) may have adverse cardiovascular effects. We evaluated whether these medications were associated with incident clinically detected atrial fibrillation (AF) or monitor-detected supraventricular ectopy (SVE), including premature atrial contractions (PACs) and supraventricular tachycardia (SVT). METHODS: We used data from the Multi-Ethnic Study of Atherosclerosis (MESA), a cohort study that enrolled 6814 Americans without clinically detected cardiovascular disease in 2000 to 2002. At the 2016 to 2018 examination, 1557 individuals received ambulatory electrocardiographic (ECG) monitoring. Longitudinal analyses investigated time-varying medication exposures at the first five exams (through 2011) in relation to incident clinically detected AF through 2015 using Cox proportional hazards regression models. Cross-sectional analyses investigated medication exposures at 2016 to 2018 examination and the risk of monitor-detected SVE using linear regression models. RESULTS: The longitudinal cohort included 6652 participants. During 12.4 years of mean follow-up, 982 participants (14.7%) experienced incident clinically detected AF. Use of opioids, gabapentinoids, and NSAIDs were not associated with incident AF. The cross-sectional analysis included 1435 participants with ECG monitoring. Gabapentinoid use was associated with an 84% greater average frequency of PACs/hour (95% CI, 25%-171%) and a 44% greater average number of runs of SVT/day (95% CI, 3%-100%). No associations were found with use of opioids or NSAIDs in cross-sectional analyses. CONCLUSIONS: In this study, gabapentinoid use was associated with SVE. Given the rapid increase in gabapentinoid use, additional studies are needed to clarify whether these medications cause cardiovascular complications.

Treatment of caffeine toxicity with metoprolol.

A 27-year-old man presented with an intentional overdose of concentrated caffeine powder that he bought over the internet. The patient received benzodiazepines and ondansetron for symptomatic treatment when he arrived in the Emergency Department (ED). Subsequently, he developed recurrent supraventricular tachycardia in the ED. The SVT was successfully treated with metoprolol. The patient's caffeine level was >90 mg/L. This is the first known report of treatment of caffeine-induced supraventricular tachycardia with metoprolol.

Arrhythmia induction using isoproterenol or epinephrine during electrophysiology study for supraventricular tachycardia.

BACKGROUND: Electrophysiology study (EPS) is an important part of the diagnosis and workup for supraventricular tachycardia (SVT). Provocative medications are used to induce arrhythmias, when they are not inducible at baseline. The most common medication is the ß1-specific agonist, isoproterenol, but recent price increases have resulted in a shift toward the nonspecific agonist, epinephrine. OBJECTIVE: We hypothesize that isoproterenol is a better induction agent for SVT during EPS than epinephrine. METHODS: We created a retrospective cohort of 131 patients, who underwent EPS and required medication infusion with either isoproterenol or epinephrine for SVT induction. The primary outcome was arrhythmia induction. RESULTS: Successful induction was achieved in 71% of isoproterenol cases and 53% of epinephrine cases (P = 0.020). Isoproterenol was significantly better than epinephrine for SVT induction during EPS (odds ratio [OR], 2.35; 95% confidence interval [CI], 1.14-4.85; P = 0.021). There was no difference in baseline variables or complications between the two groups. Other variables associated with successful arrhythmia induction included a longer procedure duration and atrioventricular nodal re-entry tachycardia as the clinical arrhythmia. In a multivariable model, isoproterenol remained significantly associated with successful induction (OR, 2.57; 95% CI, 1.002-6.59; P = 0.05). CONCLUSIONS: Isoproterenol was significantly better than epinephrine for SVT arrhythmia induction. However, epinephrine was safe and successfully induced arrhythmias in the majority of patients who received it. Furthermore, when atropine was added in epinephrine-refractory cases, in a post hoc analysis there was no difference in arrhythmia induction between medications. Cost savings could thus be significant without compromising safety.

Pyridostigmine enhances atrial tachyarrhythmias in aging spontaneously hypertensive rats.

This study examined whether chronic administration of pyridostigmine, a reversible cholinesterase inhibitor, would exacerbate episodes of spontaneous atrial tachyarrhythmia (AT) in conscious, aging, spontaneously hypertensive rats (SHRs). Telemetric recordings of electrocardiogram (ECG, n = 5) and ECG/arterial pressure (n = 3) were performed in male 49-week old SHRs. After a 1-week period of continuous recording under baseline conditions, rats were implanted with osmotic minipumps that delivered pyridostigmine (15 mg/kg/day subcutaneously) for either 1 (n = 8) or 3 (n = 5) weeks. In the latter case, sympathovagal balance was assessed during the last infusion week by measuring heart rate (HR) changes in response to administration of cardiac autonomic blockers. An additional 1-week recording was performed after explantation of minipumps. Significant (P = 0.02) reductions in HR with no consistent changes in arterial pressure were observed. Frequency and duration of AT episodes were increased by pyridostigmine (0.01 ≤ P ≤ 0.07). This increase was sustained across the 3-week treatment period and reversible after cessation of treatment. Autonomic blockade revealed that intrinsic HR was above (P = 0.04) resting HR, pointing to a shift of sympathovagal balance towards vagal predominance. However, the respiratory-related component of HR variability (high-frequency power of RR interval) was lowered (P = 0.01) by pyridostigmine treatment, indicating reduced vagal modulation of HR. The results are consistent with a pathogenic role of the parasympathetic nervous system in the aging SHR model, and raise the possibility that sustained vagal activation may facilitate atrial arrhythmias.

Recalcitrant Supraventricular Tachycardia: Occult Albuterol Toxicity Due to a Factitious Disorder.

BACKGROUND: We report a case of a factitious disorder presenting with recurrent episodes of supraventricular tachycardia (SVT). CASE REPORT: A 26-year-old woman presented with recurrent episodes of SVT. Medical history included SVT, asthma, anxiety, depression, type 2 diabetes, and migraine headaches. The patient had frequent emergency department (ED) visits with complaints of chest pain, palpitations, and heart rates typically between 130 and 150 beats/min. Electrocardiograms revealed sinus tachycardia; laboratory studies were consistently normal except for periodic episodes of hypokalemia. Over the 3 years, the patient had more than 50 visits for health care and underwent multiple diagnostic evaluations, including comprehensive laboratory testing, echocardiography, Holter monitoring, and event monitoring. Given the constellation of clinical features, a plasma albuterol concentration was obtained during an ED visit for SVT, which was 17 ng/mL (reference range for peak plasma concentration after 0.04-0.1-mg inhaler dose = 0.6-1.4 ng/mL). A subsequent ED visit with a similar presentation revealed a plasma albuterol level of 11 ng/mL. The patient adamantly denied using this medication. Due to concerns about a factitious disorder, a multidisciplinary hospital discussion was planned for subsequent interventions; however, the patient was lost to follow-up. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: This is a compelling case report of a factitious disorder and occult albuterol abuse resulting in recalcitrant SVT with numerous ED visits and interventions. Patients with factitious disorders can have multiple visits for emergency care and are challenging to evaluate and treat. Albuterol toxicity can present with pronounced sinus tachycardia, fine tremor, and often with transient hypokalemia.

The effects of ketamine on dexmedetomidine-induced electrophysiologic changes in children.

BACKGROUND: Dexmedetomidine is an alpha2-adrenergic agonist used for sedation and analgesia in children. We previously showed that dexmedetomidine depresses sinus and AV nodal function resulting in adverse hemodynamic effects such as bradycardia and increased blood pressure. We hypothesized that these effects of dexmedetomidine might be antagonized by co-administration of ketamine, which has sympathomimetic properties. METHODS: Twenty-two children (ages 5-17 years) undergoing electrophysiologic (EP) study and ablation for supraventricular tachycardia were enrolled. Patients were kept sedated with continuous infusion of propofol at a fixed rate. Hemodynamic and EP parameters were measured before and after a loading dose of dexmedetomidine (1 µg·kg(-1)). A continuous infusion of dexmedetomidine (0.7 µg·kg(-1) ·h(-1)) was initiated and a ketamine loading dose (1 mg·kg(-1)), followed by continuous infusion (1 mg·kg(-1) ·h(-1)), was given. A repeat set of hemodynamic and EP parameters were then measured at the time of projected peak tissue concentration for both drugs. RESULTS: A significant increase in mean arterial pressure (MAP) was seen compared with baseline after loading of dexmedetomidine. This returned to baseline after co-administration of ketamine (mean difference between baseline and after ketamine 1.8 mmHg; 95%CI, -7.8 to 4.3; P = <0.001). A decrease in heart rate was seen after dexmedetomidine followed by a return to baseline after co-administration of ketamine (mean difference between baseline and after ketamine -6.5 bpm; 95%CI, -11.2 to -1.8; P = 0.005). Sinus node recovery time was lengthened after dexmedetomidine but returned to baseline after ketamine (mean difference between baseline and after ketamine -16.2 ms; 95%CI, -63 to 30; P = 0.014). QT was prolonged after dexmedetomidine and returned to baseline after ketamine (mean difference between baseline and after ketamine -34.2 ms; 95%CI, -48.4 to -20.2; P = 0.004). AV nodal effective refractory period was also impaired after dexmedetomidine and showed weak evidence for return to baseline function after ketamine (mean difference between baseline and after ketamine -22.8 ms; 95%CI, -40.2 to -5.2; P = 0.069). CONCLUSION: The concurrent use of ketamine may mitigate the negative chronotropic effects of dexmedetomidine.

[Persistent supraventricular tachycardia after volatile inhalational anaesthetic induction with sevoflurane in a pediatric patient].

Inhaled anaesthetic induction with sevoflurane is very common in the pediatric population. Sevoflurane systemic effects are widely known, while not all the side effects are known. We present a four year-old child who developed a persistent supraventricular tachycardia after inhaled anaesthetic induction with sevoflurane. The arrhythmia did not end until sevoflurane was stopped and changed to an intravenous continuous perfusion of hypnotic drugs (propofol and remiphentanyl). The exact mechanism for such a causal relationship with sevoflurane administration is unknown, and possible diagnoses include atrioventricular nodal reentry tachycardia (AVNRT) and the existence of an accessory pathway. An episode of persistent supraventricular tachycardia with a clear causal relationship with sevoflurane administration is not found in the literature.

Supraventricular tachycardia with the use of phentermine: case report and review of literature.

Case: A 34-year-old woman with no significant past medical history presented to the hospital with sudden onset of palpitations with associated dyspnea and chest discomfort. She denied any similar previous episodes. Initial electrocardiogram (EKG) was consistent with a short R-P interval supraventricular tachycardia (SVT). Her transthoracic echocardiogram (TTE) revealed no structural abnormalities, TSH levels were normal, and urine drug screen was negative for any recreational drugs. However, the patient had been taking phentermine for weight loss.Discussion: The exact mechanism is not clear; however, we postulate that the sympathomimetic effects of phentermine likely contribute to SVT induction through enhanced AV nodal conduction or increased atrial ectopy. Conclusions: The only medication she was taking at home was phentermine, and the palpitations did not recur after discontinuation of the drug during follow-up. It is important to collect a thorough medication history when patients present with AV nodal reentrant tachycardia (AVNRT) or other SVT.

Incessant Atrial Tachycardia Following Combination Chemotherapy with Cetuximab, Cisplatin and 5-Fluorouracil for Hypopharyngeal Cancer.

A 72-year-old man with stage IV hypopharyngeal cancer, who had been treated for three months with combination chemotherapy, was referred to our cardiology department for evaluation of transient palpitation. Combination therapy with cetuximab, cisplatin, and 5-fluorouracil per cycle had been administered intravenously for five cycles every three weeks for three months. After the admission due to slight palpitation and severe hypomagnesemia (Mg = 0.6 mmol/L), monitor ECG showed supraventricular tachycardia (SVT), which was incessantly sustained and ceased every few minutes. 12-lead ECG obtained during tachycardia demonstrated long RP' narrow QRS tachycardia. SVT was initially considered to be related to severe hypomagnesemia. However, it still occurred even after normalization of serum magnesium level. As the SVT was refractory to landiolol and verapamil, catheter ablation was performed a few days after the admission, revealing non-reentrant focal atrial tachycardia (AT) originating from the posterolateral region of the right atrium. Homogenization of the origin of the AT was then performed with radiofrequency, resulting in complete suppression of the AT. In the present case, the patient receiving the combination therapy of cetuximab, cisplatin, and 5-FU developed focal atrial tachycardia after chemotherapy, which was successfully treated with the radiofrequency catheter ablation.

Successful use of a rapid response team in the pediatric oncology outpatient setting.

In a clinic setting, the RRT, in conjunction with the ICU intensivist, succesfully treated a septic patient with fluid resuscitation and a vasoactive medication, and subsequently facilitated a quick transport to a higher level of care. St. Jude Children's Research Hospital's successful use of the RRT in the clinic setting suggests that RRTs can be used to improve patient outcomes across the spectrum of inpatient as well as outpatient hospital settings. Our experience suggests that RRTs can be beneficial in filling a gap in patient safety in outpatient clinics.