Flecainide causing elevated capture thresholds on pacemaker implantation.

Flecainide is a Vaughan Williams class 1c antiarrhythmic used to treat supraventricular and ventricular arrhythmias. It has been described as a rare cause for increased pacemaker capture thresholds. We describe a report of a patient, in her early 80s, presenting with tachy-brady syndrome on a background of permanent atrial fibrillation. She was treated with metoprolol and flecainide by her private cardiologist. Permanent right ventricular chamber pacing was recommended for her slow heart rate. At insertion of her single chamber pacemaker, she was noted to have elevated capture thresholds despite appropriate lead positioning. A flecainide level was elevated at 1.1 µg/mL, and it was subsequently ceased. This was associated with a rapid improvement in her capture threshold. Flecainide should be considered as a cause for elevated pacing thresholds at the time of implant. Particular care should be taken for at-risk groups such as the elderly and patients with renal impairment.

Effects of bradycardia, hypoxemia and early intubation on bronchopulmonary dysplasia in very preterm infants: An observational study.

BACKGROUND: Bronchopulmonary dysplasia (BPD) is the most common pulmonary complication in preterm infants. OBJECTIVES: The study aimed to explore the effects of bradycardia, hypoxemia, and early intubation on BPD in very preterm infants. METHODS: This is a prospective observational cohort study. Preterm infants with a mean gestational age of 28.67 weeks were recruited from two level III neonatal intensive care units (NICUs) in Taiwan. Continuous electrocardiography was used to monitor heart rates and oxygen saturation (SpO2). Infants were monitored for heart rates of <100 beats per minute and SpO2 levels of <90 % lasting for 30 s. Generalized estimating equations were used to analyze the effects of bradycardia, hypoxemia, and early intubation on BPD in very preterm infants. Model fit was visually assessed using receiver operating characteristic curve analysis. RESULTS: Bradycardia, hypoxemia, and early intubation significantly increased the odds of BPD among the preterm infants (N = 39) during NICU stay; the odds ratios for bradycardia, hypoxemia, and early intubation for BPD versus non-BPD were 1.058, 1.013, and 29.631, respectively (all p < 0.05). A model combining bradycardia, hypoxemia, and early intubation accurately predicted BPD development (area under the curve = 0.919). CONCLUSIONS: Bradycardia, hypoxemia, and early intubation significantly increased the odds of BPD among very preterm infants during NICU stay. The model combining bradycardia, hypoxemia, and early intubation accurately predicted BPD development.

Safety and efficacy of cardioneuroablation for vagal bradycardia in a single arm prospective study.

Cardioneuroablation (CNA) is currently considered as a promising treatment option for patients with symptomatic bradycardia caused by vagotonia. This study aims to further investigate its safety and efficacy in patients suffering from vagal bradycardia. A total of 60 patients with vagal bradycardia who underwent CNA in the First Affiliated Hospital of Xinjiang Medical University from November 2019 to June 2022. Preoperative atropine tests revealed abnormal vagal tone elevation in all patients. First, the electroanatomic structures of the left atrium was mapped out by using the Carto 3 system, according to the protocol of purely anatomy-guided and local fractionated intracardiac electrogram-guided CNA methods. The upper limit of ablation power of superior left ganglion (SLGP) and right anterior ganglion (RAGP) was not more than 45W with an ablation index of 450.Postoperative transesophageal cardiac electrophysiological examination was performed 1 to 3 months after surgery. The atropine test was conducted when appropriate. Twelve-lead electrocardiogram, Holter electrocardiogram, and skin sympathetic nerve activity were reviewed at 1, 3, 6 and 12 months after operation. Adverse events such as pacemaker implantation and other complications were also recorded to analyze the safety and efficacy of CNA in the treatment of vagus bradycardia. Sixty patients were enrolled in the study (38 males, mean age 36.67 ± 9.44, ranging from 18 to 50 years old). None of the patients had a vascular injury, thromboembolism, pericardial effusion, or other surgical complications. The mean heart rate, minimum heart rate, low frequency, low/high frequency, acceleration capacity of rate, and skin sympathetic nerve activity increased significantly after CNA. Conversely, SDNN, PNN50, rMSSD, high frequency, and deceleration capacity of rate values decreased after CNA (all P < 0.05). At 3 months after ablation, the average heart rate, maximum heart rate, and acceleration capacity of heart rate remained higher than those before ablation, and the deceleration capacity of heart rate remained lower than those before ablation and the above results continued to follow up for 12 months after ablation (all P < 0.05). There was no significant difference in other indicators compared with those before ablation (all P > 0.05). The remaining 81.67% (49/60) of the patients had good clinical results, with no episodes of arrhythmia during follow-up. CNA may be a safe and effective treatment for vagal-induced bradycardia, subject to confirmation by larger multicenter trials.

Transvenous Pacemaker Placement: A Review for Emergency Clinicians.

BACKGROUND: Transvenous pacemaker placement is an integral component of therapy for severe dysrhythmias and a core skill in emergency medicine. OBJECTIVE: This narrative review provides a focused evaluation of transvenous pacemaker placement in the emergency department setting. DISCUSSION: Temporary cardiac pacing can be a life-saving procedure. Indications for pacemaker placement include hemodynamic instability with symptomatic bradycardia secondary to atrioventricular block and sinus node dysfunction; overdrive pacing in unstable tachydysrhythmias, such as torsades de pointes; and failure of transcutaneous pacing. Optimal placement sites include the right internal jugular vein and left subclavian vein. Insertion first includes placement of a central venous catheter. The pacing wire with balloon is then advanced until electromechanical capture is obtained with the pacer in the right ventricle. Ultrasound can be used to guide and confirm lead placement using the subxiphoid or modified subxiphoid approach. The QRS segment will demonstrate ST segment elevation once the pacing wire tip contacts the endocardial wall. If mechanical capture is not achieved with initial placement of the transvenous pacer, the clinician must consider several potential issues and use an approach to evaluating the equipment and correcting any malfunction. Although life-saving in the appropriate patient, complications may occur from central venous access, right heart catheterization, and the pacing wire. CONCLUSIONS: An understanding of transvenous pacemaker placement is essential for emergency clinicians.

Unusual Tachycardia in a Patient With Chest Pain and Bradycardia.

This case report describes a patient in their 50s who presented with squeezing chest pain for 4 hours and an initial electrocardiogram showing acute inferior wall and right ventricular infarction with third-degree atrioventricular block.

Newborns with congenital complete heart block: Advice for perinatal care providers.

Congenital complete heart block (CCHB) is a rare, but a potentially life-threatening manifestation of autoimmune diseases in neonates. Bradycardia in CCHB can be misdiagnosed as foetal distress in utero and thus precipitating a Caesarean section. We report a case series of three neonates with bradycardia without any electrolyte abnormalities and structurally normal hearts with favourable outcomes.

Prognostic benefits of His-Purkinje capture in physiological pacemakers for bradycardia.

INTRODUCTION: Clinical outcomes of long-term ventricular septal pacing (VSP) without His-Purkinje capture remain unknown. This study evaluated the differences in clinical outcomes between conduction system pacing (CSP), VSP, and right ventricular pacing (RVP). METHODS: Consecutive patients with bradycardia indicated for pacing from 2016 to 2022 were prospectively followed for the clinical endpoints of heart failure (HF)-hospitalizations and all-cause mortality at 2 years. VSP was defined as septal pacing due to unsuccessful CSP implant or successful CSP followed by loss of His-Purkinje capture within 90 days. RESULTS: Among 1016 patients (age 73.9 ± 11.2 years, 47% female, 48% atrioventricular block), 612 received RVP, 335 received CSP and 69 received VSP. Paced QRS duration was similar between VSP and RVP, but both significantly longer than CSP (p < .05). HF-hospitalizations occurred in 130 (13%) patients (CSP 7% vs. RVP 16% vs. VSP 13%, p = .001), and all-cause mortality in 143 (14%) patients (CSP 7% vs. RVP 19% vs. VSP 9%, p < .001). The association of pacing modality with clinical events was limited to those with ventricular pacing (Vp) > 20% (pinteraction < .05). Adjusting for clinical risk factors among patients with Vp > 20%, VSP (adjusted hazard ratio [AHR]: 4.74, 95% confidence interval [CI]: 1.57-14.36) and RVP (AHR: 3.08, 95% CI: 1.44-6.60) were associated with increased hazard of HF-hospitalizations, and RVP (2.52, 95% CI: 1.19-5.35) with increased mortality, compared to CSP. Clinical endpoints did not differ between VSP and RVP with Vp > 20%, or amongst groups with Vp < 20%. CONCLUSION: Conduction system capture is associated with improved clinical outcomes. CSP should be preferred over VSP or RVP during pacing for bradycardia.

Influenza associated cardiac arrhythmia- a systematic review.

BACKGROUND: Influenza infection is rarely associated with cardiac conduction disorder. Cardiac arrhythmias due to such an infection have a full spectrum with ventricular arrythmias being the most common. METHODS: In our systematic review from PubMed, OVID Medline and EMBASE we have identified 23 articles describing arrythmias associated with different influenza infection. Most of them were case reports where ventricular arrhythmias were the most common. RESULTS: Complete heart block after influenza infection is usually temporary and a permanent pacemaker is rarely needed. There are reports of Influenza associated with arrhythmias in adults, neonates, and even fetuses in pregnant woman. Different mechanisms were described in literatures by which influenza causes arrhythmias such as interleukin 6 & tumor necrosis factor-alpha mediated inflammatory response, sympathetic overactivation, focal myocarditis and cleavage of angiotensin converting enzyme 2 protein which is cardioprotective. CONCLUSIONS: ACE 2 binder influenza viruses have more prone to be associated with cardiac conduction disorder. Oseltamivir for influenza infection is also associated with bradycardia and can shorten or lengthen QT segment. Influenza vaccination has found to be protective from cardiac arrhythmia.

Oral Albuterol Treatment in Three Pediatric Patients with Bradycardia: A Novel Therapy.

Clinically significant bradycardia is an uncommon problem in children, but one that can cause significant morbidity and sometimes necessitates implantation of a pacemaker. The most common causes of bradycardia are complete heart block (CHB), which can be congenital or acquired, and sinus node dysfunction, which is rare in children with structurally normal hearts. Pacemaker is indicated as therapy for the majority of children with CHB, and while early mortality is lower in postnatally diagnosed CHB than in fetal CHB, it is still up to 16%. In young children, less invasive transvenous pacemaker systems can be technically challenging to place and carry a high risk of complications, often necessitating surgical epicardial pacemaker placement, which usually entails a median sternotomy. We report three cases of pediatric patients referred for pacemaker implantation for different types of bradycardia, treated at our institution with oral albuterol with therapeutic results that avoided the need for surgical pacemaker implantation at that time.

Unstable bradycardia induced by posterior nasal packing: a rare activation of the Trigeminocardiacreflex.

A woman in her 40s presented to the emergency department with epistaxis. Anterior nasal packing was unsuccessful in achieving haemostasis. After the exchange of devices and insertion of a posterior nasal pack, the patient developed a junctional rhythm and progressively unstable bradycardia. The rhythm and bradycardia immediately improved following the removal of the posterior nasal pack. This case describes a rare occurrence of Trigeminocardiac reflex (TCR), following an insertion of a posterior nasal pack. Only one other such case has been reported and published. This case highlights the importance of raising awareness of this rare reflex and the need for prompt removal of the triggering cause in such scenarios. TCR can induce a junctional rhythm, which progresses to unstable bradycardia and may lead to asystole in susceptible individuals. The removal of the stimulus resolves the reflex and can result in prompt resolution of the bradycardia and hypotension induced via the TCR.

Positioning for lumbar puncture in newborn infants.

BACKGROUND: Lumbar puncture is a common invasive procedure performed in newborns for diagnostic and therapeutic purposes. Approximately one in two lumbar punctures fail, resulting in both short- and long-term negative consequences for the clinical management of patients. The most common positions used to perform lumbar puncture are the lateral decubitus and sitting position, and each can impact the success rate and safety of the procedure. However, it is uncertain which position best improves patient outcomes. OBJECTIVES: To assess the benefits and harms of the lateral decubitus, sitting, and prone positions for lumbar puncture in newborn infants. SEARCH METHODS: We used standard, extensive Cochrane search methods. The latest search date was 24 January 2023. SELECTION CRITERIA: We included randomized controlled trials (RCTs) and quasi-RCTs involving newborn infants of postmenstrual age up to 46 weeks and 0 days, undergoing lumbar puncture for any indication, comparing different positions (i.e. lateral decubitus, sitting, and prone position) during the procedure. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods. We used the fixed-effect model with risk ratio (RR) and risk difference (RD) for dichotomous data and mean difference (MD) and standardized mean difference (SMD) for continuous data, with their 95% confidence intervals (CI). Our primary outcomes were successful lumbar puncture procedure at the first attempt; total number of lumbar puncture attempts; and episodes of bradycardia. We used GRADE to assess the certainty of evidence for each outcome. MAIN RESULTS: We included five studies with 1476 participants. Compared to sitting position: lateral decubitus position probably results in little to no difference in successful lumbar puncture procedure at the first attempt (RR 0.99, 95% CI 0.88 to 1.12; RD 0.00, 95% CI -0.06 to 0.05; I2 = 47% and 46% for RR and RD, respectively; 2 studies, 1249 infants, low-certainty evidence). None of the studies reported the total number of lumbar puncture attempts as specified in this review. Lateral decubitus position likely increases episodes of bradycardia (RR 1.72, 95% CI 1.08 to 2.76; RD 0.03, 95% CI 0.00 to 0.05; number needed to treat for an additional harmful outcome (NNTH) = 33; I2 = not applicable and 69% for RR and RD, respectively; 3 studies, 1279 infants, moderate-certainty evidence) and oxygen desaturation (RR 2.10, 95% CI 1.42 to 3.08; RD 0.06, 95% CI 0.03 to 0.09; NNTH = 17; I2 = not applicable and 96% for RR and RD, respectively; 2 studies, 1249 infants, moderate-certainty evidence). Lateral decubitus position results in little to no difference in time to perform the lumbar puncture compared to sitting position (I2 = not applicable; 2 studies; 1102 infants; high-certainty evidence; in one of the study median and IQR to report time to perform the lumbar puncture were 8 (5-13) and 8 (5-12) in the lateral and sitting position, respectively, I2 = not applicable; 1 study, 1082 infants; in the other study: mean difference 2.00, 95% CI -4.98 to 8.98; I2 = not applicable; 1 study, 20 infants). Lateral decubitus position may result in little to no difference in the number of episodes of apnea during the procedure (RR not estimable; RD 0.00, 95% CI -0.03 to 0.03; I2 = not applicable and 0% for RR and RD, respectively; 2 studies, 197 infants, low-certainty evidence). No studies reported apnea defined as number of infants with one or more episodes during the procedure. Compared to prone position: lateral decubitus position may reduce successful lumbar puncture procedure at first attempt (RR 0.75, 95% CI 0.63 to 0.90; RD -0.21, 95% CI -0.34 to -0.09; number needed to treat for an additional beneficial outcome = 5; I2 = not applicable; 1 study, 171 infants, low-certainty evidence). None of the studies reported the total number of lumbar puncture attempts or episodes of apnea. Pain intensity during and after the procedure was reported using a non-validated pain scale. None of the studies comparing lateral decubitus versus prone position reported the other critical outcomes of this review. AUTHORS' CONCLUSIONS: When compared to sitting position, lateral decubitus position probably results in little to no difference in successful lumbar puncture procedure at first attempt. None of the included studies reported the total number of lumbar puncture attempts as specified in this review. Furthermore, infants in a sitting position likely experience less episodes of bradycardia and oxygen desaturation than in the lateral decubitus, and there may be little to no difference in episodes of apnea. Lateral decubitus position results in little to no difference in time to perform the lumbar puncture compared to sitting position. Pain intensity during and after the procedure was reported using a pain scale that was not included in our prespecified tools for pain assessment due to its high risk of bias. Most study participants were term newborns, thereby limiting the applicability of these results to preterm babies. When compared to prone position, lateral decubitus position may reduce successful lumbar puncture procedure at first attempt. Only one study reported on this comparison and did not evaluate adverse effects. Further research exploring harms and benefits and the effect on patients' pain experience of different positions during lumbar puncture using validated pain scoring tool may increase the level of confidence in our conclusions.

Exerted force on the face mask in preterm infants at birth is associated with apnoea and bradycardia.

BACKGROUND: During stabilisation of preterm infants at birth, a face mask is used to provide respiratory support. However, application of these masks may activate cutaneous stretch receptors of the trigeminal nerve, causing apnoea and bradycardia. This study investigated the amount of force exerted on the face mask during non-invasive ventilation of preterm infants at birth and whether the amount of exerted force is associated with apnoea and bradycardia. METHODS: A prospective observational study was performed in preterm infants born <32 weeks of gestation who were stabilised at birth. During the first 10 minutes of respiratory support, we measured breathing and heart rate as well as the amount of force exerted on a face mask using a custom-made pressure sensor placed on top of the face mask. RESULTS: Thirty infants were included (median (IQR) gestational age(GA) 28+3 (27+0-30+0) weeks, birthweight 1104 (878-1275) grams). The median exerted force measured was 297 (198-377) grams, ranging from 0 to 1455 grams. Significantly more force was exerted on the face mask during positive pressure ventilation when compared to CPAP (410 (256-556) vs 286 (190-373) grams, p = 0.009). In a binary logistic regression model, higher forces were associated with an increased risk of apnoea (OR = 1.607 (1.556-1.661), p < 0.001) and bradycardia (OR = 1.140 (1.102-1.180), p < 0.001) during the first 10 minutes of respiratory support at birth. CONCLUSION: During mask ventilation, the median exerted force on a face mask was 297 grams with a maximum of 1455 grams. Higher exerted forces were associated apnoea and bradycardia during the first 10 minutes of respiratory support at birth.

Positioning for lumbar puncture in newborn infants.

BACKGROUND: Lumbar puncture is a common invasive procedure performed in newborns for diagnostic and therapeutic purposes. Approximately one in two lumbar punctures fail, resulting in both short- and long-term negative consequences for the clinical management of patients. The most common positions used to perform lumbar puncture are the lateral decubitus and sitting position, and each can impact the success rate and safety of the procedure. However, it is uncertain which position best improves patient outcomes. OBJECTIVES: To assess the benefits and harms of the lateral decubitus, sitting, and prone positions for lumbar puncture in newborn infants. SEARCH METHODS: We used standard, extensive Cochrane search methods. The latest search date was 24 January 2023. SELECTION CRITERIA: We included randomized controlled trials (RCTs) and quasi-RCTs involving newborn infants of postmenstrual age up to 46 weeks and 0 days, undergoing lumbar puncture for any indication, comparing different positions (i.e. lateral decubitus, sitting, and prone position) during the procedure. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods. We used the fixed-effect model with risk ratio (RR) and risk difference (RD) for dichotomous data and mean difference (MD) and standardized mean difference (SMD) for continuous data, with their 95% confidence intervals (CI). Our primary outcomes were successful lumbar puncture procedure at the first attempt; total number of lumbar puncture attempts; and episodes of bradycardia. We used GRADE to assess the certainty of evidence for each outcome. MAIN RESULTS: We included five studies with 1476 participants. Compared to sitting position: lateral decubitus position may result in little to no difference in successful lumbar puncture procedure at the first attempt (RR 0.93, 95% CI 0.85 to 1.02; RD -0.04, 95% CI -0.09 to 0.01; I2 = 70% and 72% for RR and RD, respectively; 2 studies, 1249 infants, low-certainty evidence). None of the studies reported the total number of lumbar puncture attempts. Lateral decubitus position likely increases episodes of bradycardia (RR 1.72, 95% CI 1.08 to 2.76; RD 0.03, 95% CI 0.00 to 0.05; number needed to treat for an additional harmful outcome (NNTH) = 33; I2 = not applicable and 69% for RR and RD, respectively; 3 studies, 1279 infants, moderate-certainty evidence) and oxygen desaturation (RR 2.10, 95% CI 1.42 to 3.08; RD 0.06, 95% CI 0.03 to 0.09; NNTH = 17; I2 = not applicable and 96% for RR and RD, respectively; 2 studies, 1249 infants, moderate-certainty evidence). The evidence is very uncertain regarding the effect of lateral decubitus position on time to perform the lumbar puncture (MD 2.00, 95% CI -4.98 to 8.98; I2 = not applicable; 1 study, 20 infants, very low-certainty evidence). Lateral decubitus position may result in little to no difference in the number of episodes of apnea during the procedure (RR not estimable; RD 0.00, 95% CI -0.03 to 0.03; I2 = not applicable and 0% for RR and RD, respectively; 2 studies, 197 infants, low-certainty evidence). No studies reported apnea defined as number of infants with one or more episodes during the procedure. Compared to prone position: lateral decubitus position may reduce successful lumbar puncture procedure at first attempt (RR 0.75, 95% CI 0.63 to 0.90; RD -0.21, 95% CI -0.34 to -0.09; number needed to treat for an additional beneficial outcome = 5; I2 = not applicable; 1 study, 171 infants, low-certainty evidence). None of the studies reported the total number of lumbar puncture attempts or episodes of apnea. Pain intensity during and after the procedure was reported using a non-validated pain scale. None of the studies comparing lateral decubitus versus prone position reported the other critical outcomes of this review. AUTHORS' CONCLUSIONS: When compared to sitting position, lateral decubitus position may result in little to no difference in successful lumbar puncture procedure at first attempt. None of the included studies reported the total number of lumbar puncture attempts. Furthermore, infants in a lateral decubitus position likely experience more episodes of bradycardia and oxygen desaturation, and there may be little to no difference in episodes of apnea. The evidence is very uncertain regarding time to perform lumbar puncture. Pain intensity during and after the procedure was reported using a pain scale that was not included in our prespecified tools for pain assessment due to its high risk of bias. Most study participants were term newborns, thereby limiting the applicability of these results to preterm babies. When compared to prone position, lateral decubitus position may reduce successful lumbar puncture procedure at first attempt. Only one study reported on this comparison and did not evaluate adverse effects. Further research exploring harms and benefits and the effect on patients' pain experience of different positions during lumbar puncture using validated pain scoring tool may increase the level of confidence in our conclusions.

Application of Dexmedetomidine in Epidural Labor Analgesia: A Systematic Review and Meta-Analysis on Randomized Controlled Trials.

OBJECTIVES: To summarize and appraise the use of dexmedetomidine in epidural labor analgesia, we conducted a systematic review and meta-analysis of randomized controlled trials (RCTs). METHODS: We conducted the literature search about the RCTs of epidural labor analgesia with or without dexmedetomidine from inception until November 1, 2022, in the following databases: PubMed, Cochrane Library, and Embase. The primary outcome was visual analog scale (VAS) within 2 hours after epidural intubation. The secondary outcomes included the duration of the first and second labor stages, Apgar score, umbilical blood pH, dosage of analgesics, and side effects. RESULTS: Eight RCTs including 846 parturients were included. The VAS score of the dexmedetomidine group was significantly lower than that of the control group at the time of 15 minutes (mean difference [MD] -1.41, 95% confidence interval [CI] -2.23, -0.59), 30 minutes (MD -1.02, 95% CI -1.70, -0.33), 60 minutes (MD -0.90, 95% CI -1.36, -0.44), and 90 minutes (MD -0.70, 95% CI -1.16, -0.23). The incidence of pruritus in the dexmedetomidine group was lower than that of the control group （MD 0.28, 95% CI 0.11, 0.74), but the incidence of maternal bradycardia was higher (MD 6.41, 95% CI 1.64, 25.04). There were no significant difference in other outcomes. DISCUSSION: Dexmedetomidine combined with local anesthetic for epidural labor analgesia can improve the VAS score of parturients. Except for the increased incidence of maternal bradycardia, it seems to be safe for the parturients and fetuses.

High spinal cord injury precipitating syncope: a rare indication for pacemaker insertion.

The current evidence for vasovagal syncope management is that cardiac pacing is only indicated in a highly select group of patients where symptoms can be linked to bradycardic episodes. High spinal cord injury can lead to autonomic dysfunction and sympathetic nervous system hypoactivity. A high spinal cord injury can theoretically precipitate profound bradycardia leading to haemodynamic instability and syncope. A patient in his 50s with a history of C2 spinal injury was admitted to our tertiary centre for management of what was initially thought to be septic shock causing hypotension and syncope. With evidence to suggest this patient's presentation may be profound reflex syncope in the context of unopposed parasympathetic signalling, consensus was reached to implant a permanent pacemaker. Remarkably, the patient's haemodynamics stabilised and there were no further episodes of syncope.