Newborn heart rate monitoring methods at birth and clinical outcomes: A systematic review.

Aim: Compare heart rate assessment methods in the delivery room on newborn clinical outcomes. Methods: A search of Medline, SCOPUS, CINAHL and Cochrane was conducted between January 1, 1946, to until August 16, 2023. (CRD 42021283438) Study Selection was based on predetermined criteria. Reviewers independently extracted data, appraised risk of bias and assessed certainty of evidence. Results: Two randomized controlled trials involving 91 newborns and 1 nonrandomized study involving 632 newborns comparing electrocardiogram (ECG) to auscultation plus pulse oximetry were included. No studies were found that compared any other heart rate measurement methods and reported clinical outcomes. There was no difference between the ECG and control group for duration of positive pressure ventilation, time to heart rate ≥ 100 beats per minute, epinephrine use or death before discharge. In the randomized studies, there was no difference in rate of tracheal intubation [RR 1.34, 95% CI (0.69-2.59)]. No participants received chest compressions. In the nonrandomized study, fewer infants were intubated in the ECG group [RR 0.75, 95% CI (0.62-0.90)]; however, for chest compressions, benefit or harm could not be excluded. [RR 2.14, 95% (CI 0.98-4.70)]. Conclusion: There is insufficient evidence to ascertain clinical benefits or harms associated with the use of ECG versus pulse oximetry plus auscultation for heart rate assessment in newborns in the delivery room.

Procedural and Intermediate-term Results of the Electroanatomical-guided Cardioneuroablation for the Treatment of Supra-Hisian Second- or Advanced-degree Atrioventricular Block: the PIRECNA multicentre registry.

AIMS: Prior case series showed promising results for cardioneuroablation in patients with vagally induced atrioventricular blocks (VAVBs). We aimed to examine the acute procedural characteristics and intermediate-term outcomes of electroanatomical-guided cardioneuroablation (EACNA) in patients with VAVB. METHODS AND RESULTS: This international multicentre retrospective registry included data collected from 20 centres. Patients presenting with symptomatic paroxysmal or persistent VAVB were included in the study. All patients underwent EACNA. Procedural success was defined by the acute reversal of atrioventricular blocks (AVBs) and complete abolition of atropine response. The primary outcome was occurrence of syncope and daytime second- or advanced-degree AVB on serial prolonged electrocardiogram monitoring during follow-up. A total of 130 patients underwent EACNA. Acute procedural success was achieved in 96.2% of the cases. During a median follow-up of 300 days (150, 496), the primary outcome occurred in 17/125 (14%) cases with acute procedural success (recurrence of AVB in 9 and new syncope in 8 cases). Operator experience and use of extracardiac vagal stimulation were similar for patients with and without primary outcomes. A history of atrial fibrillation, hypertension, and coronary artery disease was associated with a higher primary outcome occurrence. Only four patients with primary outcome required pacemaker placement during follow-up. CONCLUSION: This is the largest multicentre study demonstrating the feasibility of EACNA with encouraging intermediate-term outcomes in selected patients with VAVB. Studies investigating the effect on burden of daytime symptoms caused by the AVB are required to confirm these findings.

Favipiravir-induced bradycardia: A case report.

Key Clinical Message: The purpose of this case report is to reveal one of the cardiovascular side effects of favipiravir, sinus bradycardia. Abstract: Favipiravir has emerged as a potential treatment for COVID-19, with its antiviral properties showing promise in inhibiting viral replication. However, concerns regarding its safety profile, particularly its cardiac adverse effects, remain a subject of debate. We present the case of a 58-year-old man with a history of diabetes mellitus and chronic obstructive pulmonary disease who developed bradycardia following treatment with favipiravir for COVID-19 pneumonia. Despite being asymptomatic, the patient exhibited sinus bradycardia, which resolved upon discontinuation of favipiravir. Favipiravir has been associated with QT prolongation and sinus bradycardia, though the exact mechanisms remain unclear. Our case adds to the growing body of evidence highlighting the potential cardiac complications of favipiravir therapy in COVID-19 patients. Further research is warranted to clarify the underlying mechanisms and optimize patient management strategies. Clinicians should be cautious for cardiac adverse events when prescribing favipiravir for COVID-19 treatment, especially in patients with preexisting cardiac conditions. Continued research is essential to ensure the safe and effective use of favipiravir in the management of COVID-19.

Typical Exertional Angina With No Angiographic Coronary Artery Disease.

Cardiac syndrome X (CSX) is a cardiac condition that is a diagnosis of exclusion. Patients usually present with terrible chest pains suggestive of myocardial infarction, but angiogram imaging shows no occlusion in the coronary vessels that would be suggestive of coronary artery disease. CSX is more commonly seen in women, but this case report demonstrates a different clinical presentation of CSX in a young, otherwise healthy male patient. The 38-year-old male patient presented to the emergency room with chest discomfort radiating to the left arm and to the left jaw. The chest pain started after the patient went for a jog, with the pain lasting for a couple of hours. The electrocardiogram (ECG) was abnormal, showing nonspecific ST changes and unremarkable troponin levels. The patient underwent a coronary angiogram, which was unremarkable. Three years later, the patient presented once more with chest heaviness that occurred again after going for a run. The patient's troponins were unremarkable, and an ECG test showed a new onset of AV block. Due to the ongoing chest pain, the patient received another coronary angiogram. This showed that the coronary vessels had no indications of occlusion. The patient was discharged and scheduled to follow up with their cardiologist for an extensive discussion about medications for their condition. This case report should bring awareness of the classical presentation of this disease in an uncommon population group and a way to identify this syndrome once exclusions have been made on previous hospitalizations.

Exploration of COVID-19 associated bradycardia using heart rate variability analysis in a case-control study of ARDS patients.

BACKGROUND: Bradycardia and dysautonomia observed during SARS-Cov2 infection suggests involvement of the autonomic nervous system (ANS). Limited data exists on ANS dysregulation and its association with outcomes in patients with acute respiratory distress syndrome (ARDS) related to COVID-19 (C-ARDS) or other etiologies (NC-ARDS). OBJECTIVES: We aimed to explore sympathovagal balance, assessed by heart rate variability (HRV), and its clinical prognostic value in C-ARDS compared with NC-ARDS. METHODS: A single-center, prospective case-control study was conducted. Consecutive patients meeting ARDS criteria between 2020 and 2022 were included. HRV was assessed using 1-hour electrographic tracing during a stable, daytime period. RESULTS: Twenty-four patients with C-ARDS and 19 with NC-ARDS were included. Age, sex and ARDS severity were similar between groups. The median heart rate was markedly lower in the C-ARDS group than in the NC-ARDS group (60 [53-72] versus 101 [91-112] bpm, p<.001). Most of HRV parameters were significantly increased in patients with C-ARDS. HRV correlated with heart rate only in patients with C-ARDS. A positive correlation was found between the low-to high-frequency ratio (LF/HF) and length of intensive care unit stay (r = 0.576, p<.001). CONCLUSION: This study confirmed that C-ARDS was associated with marked bradycardia and severe ANS impairment, suggesting a sympathovagal imbalance with vagal overtone. Poor outcomes appeared to be more related to sympathetic rather than parasympathetic hyperactivation.

Fast and accurate newborn heart rate monitoring at birth: A systematic review.

Aim: To examine speed and accuracy of newborn heart rate measurement by various assessment methods employed at birth. Methods: A search of Medline, SCOPUS, CINAHL and Cochrane was conducted between January 1, 1946, to until August 16, 2023. (CRD 42021283364) Study selection was based on predetermined criteria. Reviewers independently extracted data, appraised risk of bias and assessed certainty of evidence. Results: Pulse oximetry is slower and less precise than ECG for heart rate assessment. Both auscultation and palpation are imprecise for heart rate assessment. Other devices such as digital stethoscope, Doppler ultrasound, an ECG device using dry electrodes incorporated in a belt, photoplethysmography and electromyography are studied in small numbers of newborns and data are not available for extremely preterm or bradycardic newborns receiving resuscitation. Digital stethoscope is fast and accurate. Doppler ultrasound and dry electrode ECG in a belt are fast, accurate and precise when compared to conventional ECG with gel adhesive electrodes. Limitations: Certainty of evidence was low or very low for most comparisons. Conclusion: If resources permit, ECG should be used for fast and accurate heart rate assessment at birth. Pulse oximetry and auscultation may be reasonable alternatives but have limitations. Digital stethoscope, doppler ultrasound and dry electrode ECG show promise but need further study.

Is conduction system pacing a panacea for pacemaker therapy?

INTRODUCTION: While supported by robust evidence and decades of clinical experience, right ventricular apical pacing for bradycardia is associated with a risk of progressive left ventricular dysfunction. Cardiac resynchronization therapy for heart failure with reduced ejection fraction can result in limited electrical resynchronization due to anatomical constraints and epicardial stimulation. In both settings, directly stimulating the conduction system below the atrio-ventricular node (either the bundle of His or the left bundle branch area) has potential to overcome these limitations. Conduction system pacing has met with considerable enthusiasm in view of the more physiological electrical conduction pattern, is rapidly becoming the preferred option of pacing for bradycardia, and is gaining momentum as an alternative to conventional biventricular pacing. AREAS COVERED: This article provides a review of the current efficacy and safety data for both people requiring treatment for bradycardia and the management of heart failure with conduction delay and discusses the possible future roles for conduction system pacing in routine clinical practice. EXPERT OPINION: Conduction system pacing might be the holy grail of pacemaker therapy without the disadvantages of current approaches. However, hypothesis and enthusiasm are no match for robust data, demonstrating at least equivalent efficacy and safety to standard approaches.

Silent and Cold: A Case of Bradycardia Associated With Isolated Hypothermia.

Sinus bradycardia is defined as a heart rate of less than 60 beats per minute and can occur as an adaptive response but can also be pathologic. Sinus bradycardia can be a normal finding in children, individuals who exercise often, and as a physiologic response during sleep. Pathologic causes of sinus bradycardia include sinus node dysfunction, medications, acute myocardial infarction, heart failure, obstructive sleep apnea, exaggerated vagal activity, increased intracranial hypertension, infection, hypothyroidism, hypothermia, anorexia nervosa, and prolonged hypoxia. When pathologic, addressing the underlying cause will lead to an improvement in heart rate. Here, we present a case of sinus bradycardia in a 61-year-old female with hypothermia. Evaluation for common causes of bradycardia including cardiac evaluation was unremarkable. Treatment of hypothermia led to the resolution of bradycardia. The importance of the case is to help clinicians recognize hypothermia as a cause of bradycardia.

Diagnosis and Management of Fetal Arrhythmias in the Current Era.

Diagnosis and management of fetal arrhythmias have changed over the past 40-50 years since propranolol was first used to treat fetal tachycardia in 1975 and when first attempts were made at in utero pacing for complete heart block in 1986. Ongoing clinical trials, including the FAST therapy trial for fetal tachycardia and the STOP-BLOQ trial for anti-Ro-mediated fetal heart block, are working to improve diagnosis and management of fetal arrhythmias for both mother and fetus. We are also learning more about how "silent arrhythmias", like long QT syndrome and other inherited channelopathies, may be identified by recognizing "subtle" abnormalities in fetal heart rate, and while echocardiography yet remains the primary tool for diagnosing fetal arrhythmias, research efforts continue to advance the clinical envelope for fetal electrocardiography and fetal magnetocardiography. Pharmacologic management of fetal arrhythmias remains one of the most successful achievements of fetal intervention. Patience, vigilance, and multidisciplinary collaboration are key to successful diagnosis and treatment.

A leadless ventricular pacemaker providing atrioventricular synchronous pacing in the real-world setting: 12-Month results from the Micra AV post-approval registry.

BACKGROUND: Advances in leadless pacemaker technology have enabled accelerometer-based atrioventricular (AV) synchronous pacing by sensing atrial mechanical contraction. OBJECTIVE: The purpose of this study was to report the performance of the Micra AV leadless pacemaker from the worldwide Micra AV post-approval registry (PAR) through 12 months. METHODS: The Micra AV PAR is a prospective, single-arm, observational registry designed to assess the safety and effectiveness of Micra AV in a real-world setting. For the present interim analysis, major complications and system revisions through 12 months were summarized and compared to a historical cohort of 2667 transvenous dual-chamber pacing patients. RESULTS: The device was successfully implanted in 796 of 801 patients (99.4%) at 97 centers in 19 countries. Micra AV patients were older (74.1 years vs 71.1 years; P < .0001) with a higher incidence of renal disease (22.3% vs 9.8%; P < .0001) compared with transvenous dual-chamber patients. Through 12 months, the major complication rate was 3.7% in Micra AV patients compared with 8.8% in transvenous dual-chamber patients (hazard ratio 0.42; 95% confidence interval 0.28-0.61; P < .001). The system revision rate was 1.5% in Micra AV patients compared with 5.5% for transvenous dual-chamber patients (hazard ratio 0.25; 95% confidence interval 0.13-0.47; P < .001); this reduction was largely driven by the absence of lead dislodgments requiring revision. The median AV synchrony index was 79.4% (interquartile range 65.2%-86.4%) in patients paced >90%. CONCLUSION: The Micra AV leadless pacemaker was implanted with a high rate of success in patients with multiple comorbidities, with a significantly lower rate of complications and system revisions through 12 months compared to a historical cohort of patients with transvenous dual-chamber pacemakers.

Fetal bradyarrhythmias: classification, monitoring and outcomes of 40 cases at a single center.

OBJECTIVES: To assess congenital fetal bradyarrhythmias with regard to etiological causes, features, risk factors, and prognosis. METHODS: This retrospective study involved fetuses with fetal bradyarrhythmias. All fetuses were evaluated by ultrasonography. Parental ECGs and family histories were obtained, and maternal autoantibodies were measured. Gestational age at diagnosis, fetal atrial and ventricular rates at presentation, type of bradyarrhythmias, the presence or absence of a congenital heart defect (CHD), fetal hydrops, fetal myocardial dysfunction, extra-cardiac abnormalities, maternal autoimmune diseases, maternal autoantibodies as well as prenatal treatment, and neonatal outcome were collected. RESULTS: Of the 40 fetuses included in the study, 11 had maternal rheumatologic disease, 16 had complex cardiac anomalies such as left and right isomerism. Fetuses with CHD significantly differed from those without CHD with increased rates of extra-cardiac anomalies, hydrops, fetal deaths and shorter survival after 28 days (p<0.05). Survival was significantly better in fetuses with maternal rheumatic disease as compared with those with no maternal rheumatic disease (p<0.05). Maternal anti-arrhythmic therapy was administered in 11 fetuses. In utero maternal treatment resulted in no significant difference in the course of arrhythmia or hydrops in fetuses with or without maternal rheumatic disease (p<0.05). In regression analysis, the absence of fetal hydrops was the only independent factor associated with survival (p=0.04). CONCLUSIONS: The course of bradyarrhythmias, along with survival, seems to be more favorable in fetuses with maternal rheumatic disease than in those with CHD, especially left and right isomerism. Hydrops was the sole independent factor associated with poor survival.

Tizanidine-Induced Bradycardia Without Concomitant Medications: A Case Report.

A 37-year-old woman was admitted to our hospital due to a loss of consciousness. She had been taking 2 mg of tizanidine for two months to manage shoulder muscle pain at night. On admission, an electrocardiogram showed sinus bradycardia with a heart rate of 30 bpm and QT prolongation (QTc 495 msec). She had a temporary pacemaker inserted in the catheterization room, after which an improvement in her level of consciousness was observed. There were no apparent endocrine disorders or structural heart diseases. The administration was discontinued after admission, and 12 hours after admission, her heart rate normalized to a sinus rhythm of 70-100 bpm, and QTc improved to 431 msec. Therefore, she was diagnosed with tizanidine-induced bradycardia. Although reports of tizanidine-induced bradycardia are rare, tizanidine's central α2 agonistic effects can cause bradycardia, necessitating caution.

Sleep Bruxism and Sleep Structure in Comorbid Insomnia and Obstructive Sleep Apnea (COMISA) Syndrome: A Polysomnographic Study.

Introduction: Comorbid insomnia and obstructive sleep apnea (COMISA) is not a well-identified sleep disorder, despite having a significant impact on health. This study investigates the relationship between sleep bruxism (SB) and sleep architecture in patients with COMISA, obstructive sleep apnea (OSA), and in those without any sleep disorders. Methods: 119 patients were included in the study and divided into three groups: OSA, COMISA, and a control group. Polysomnographic (PSG) examination provided parameters related to sleep architecture, OSA, and characteristics of SB. Results: The bruxism episode index (BEI) and other SB parameters were not found to be statistically different between the three groups (p > 0.05). There was no statistical difference in measured sleep architecture between the COMISA and OSA groups (p > 0.05). In comparison to the control group, participants in the COMISA group were found to have an increased apnea-hypopnea index (AHI), oxygen desaturation index (ODI), respiratory disturbance index (RDI), all arousals (AA), and respiratory arousals (RA) (p < 0.05). Among COMISA patients, AA and RA were shown to have a positive linear correlation with the number of bradycardia events per hour (r = 0.49, r = 0.48, p < 0.05). Conclusions: SB does not occur in patients with COMISA more frequently than in patients with OSA or those without any sleep disorders. PSG parameters are not specific for COMISA; therefore, in order to differentiate this disorder from OSA alone, a comprehensive patient assessment has to be performed.

Machine learning model with output correction: Towards reliable bradycardia detection in neonates.

Bradycardia is a commonly occurring condition in premature infants, often causing serious consequences and cardiovascular complications. Reliable and accurate detection of bradycardia events is pivotal for timely intervention and effective treatment. Excessive false alarms pose a critical problem in bradycardia event detection, eroding trust in machine learning (ML)-based clinical decision support tools designed for such detection. This could result in disregarding the algorithm's accurate recommendations and disrupting workflows, potentially compromising the quality of patient care. This article introduces an ML-based approach incorporating an output correction element, designed to minimise false alarms. The approach has been applied to bradycardia detection in preterm infants. We applied five ML-based autoencoder techniques, using recurrent neural network (RNN), long-short-term memory (LSTM), gated recurrent unit (GRU), 1D convolutional neural network (1D CNN), and a combination of 1D CNN and LSTM. The analysis is performed on ∼440 hours of real-time preterm infant data. The proposed approach achieved 0.978, 0.73, 0.992, 0.671 and 0.007 in AUC-ROC, AUC-PRC, recall, F1 score, and false positive rate (FPR) respectively and a false alarms reduction of 36% when compared with methods without the correction approach. This study underscores the imperative of cultivating solutions that alleviate alarm fatigue and encourage active engagement among healthcare professionals.

The effectiveness of dexmedetomidine for preventing acute kidney injury after surgery: a systematic review and meta-analysis.

Background: Postoperative acute kidney injury (AKI) is a serious and distressing complication connected to various adverse outcomes following the surgical operation. Controversy remains regarding the dexmedetomidine's preventive impact on postoperative AKI. Therefore, this investigation aims to explore the efficiency and safety of dexmedetomidine in preventing AKI after surgical operation. Methods: We systematically searched electronic databases such as PubMed, Embase, Web of Science, and the Cochrane Library to detect eligible randomized controlled studies that used dexmedetomidine for the prevention of AKI following operation up to April 30, 2023. The main outcome evaluated was AKI incidence. The evidence quality was assessed employing the Grading of Recommendations Assessment, Development, and Evaluation. Results: The meta-analysis included 25 trials, including 3,997 individuals. Of these, 2,028 were in the dexmedetomidine group, and 1,969 were in the control group. The result showed that patients administered dexmedetomidine significantly decreased the AKI incidence following surgical operation in contrast to the control group (risk ratio, 0.60; 95% confidence intervals, 0.45-0.78; p < 0.05; I 2 = 46%). In addition, dexmedetomidine decreased the period of hospitalization in both the intensive care unit (ICU) and the hospital while also reducing postoperative delirium (POD) occurrence. However, dexmedetomidine elevated the incidence of bradycardia but did not have a significant impact on other indicators. Conclusion: Our meta-analysis indicates that the dexmedetomidine treatment reduces the postoperative AKI and POD risk while also shortening the time of hospitalization in the ICU and hospital. However, it is connected to an increased bradycardia risk.

The inciting factor for bradycardia in COVID-19 patients: a potential harm of steroid treatment.

Background: The coronavirus disease 2019 (COVID-19) is a condition caused by the novel severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2). Although several papers have reported the presence bradycardia in patients with COVID-19, the pathophysiology behind this remains unclear. Therefore, we investigated the presence of bradycardia in patients with COVID-19. Methods: We conducted a retrospective cohort study in a total of 153 patients with COVID-19 and 90 patients with influenza who were hospitalized in our hospital from January 1, 2020 to December 31, 2021 and from January 1, 2014 to December 31, 2021, respectively. Data were collected from patient medical records, which included sex, age, duration of hospitalization, pneumonia complications, supplemental oxygen therapy, antiviral treatment, past history, and vital signs. Results: After adjustment, the incidence of bradycardia and steroid use in patients with COVID-19 were significantly higher than those in patients with influenza (P=0.007 and P<0.001, respectively). We then compared the detailed characteristics of patients with COVID-19 to evaluate risk factors for bradycardia. Multivariate logistic regression analysis revealed that steroid use was significantly related to bradycardia [P=0.031; odds ratio (OR): 3.67; 95% confidence interval (CI): 1.12-11.96]. Overall, results showed a higher incidence of bradycardia in patients with COVID-19 who received steroid treatment. Conclusions: Our results showed that steroid treatment in patients with COVID-19 may be associated with the incidence of bradycardia.

Influence of hypercapnia and hypercapnic hypoxia on the heart rate response to apnea.

We aimed to determine the relative contribution of hypercapnia and hypoxia to the bradycardic response to apneas. We hypothesized that apneas with hypercapnia would cause greater bradycardia than normoxia, similar to the response seen with hypoxia, and that apneas with hypercapnic hypoxia would induce greater bradycardia than hypoxia or hypercapnia alone. Twenty-six healthy participants (12 females; 23 ± 2 years; BMI 24 ± 3 kg/m2) underwent three gas challenges: hypercapnia (+5 torr end tidal partial pressure of CO2 [PETCO2]), hypoxia (50 torr end tidal partial pressure of O2 [PETO2]), and hypercapnic hypoxia (combined hypercapnia and hypoxia), with each condition interspersed with normocapnic normoxia. Heart rate and rhythm, blood pressure, PETCO2, PETO2, and oxygen saturation were measured continuously. Hypercapnic hypoxic apneas induced larger bradycardia (-19 ± 16 bpm) than normocapnic normoxic apneas (-11 ± 15 bpm; p = 0.002), but had a comparable response to hypoxic (-19 ± 15 bpm; p = 0.999) and hypercapnic apneas (-14 ± 14 bpm; p = 0.059). Hypercapnic apneas were not different from normocapnic normoxic apneas (p = 0.134). After removal of the normocapnic normoxic heart rate response, the change in heart rate during hypercapnic hypoxia (-11 ± 16 bpm) was similar to the summed change during hypercapnia+hypoxia (-9 ± 10 bpm; p = 0.485). Only hypoxia contributed to this bradycardic response. Under apneic conditions, the cardiac response is driven by hypoxia.

Oculocardiac Reflex in a Patient With Maxillofacial Trauma: A Case Study and Literature Review.

Oculocardiac reflex (OCR), presenting as bradycardia and asystole, is a potential intraoperative complication that may occur during maxillofacial trauma surgery. Bradycardia is the most common symptom of this phenomenon. Surgeons should be aware of its long-term effects, such as arrhythmias and even cardiac arrest. We report the case of a 40-year-old male patient with a fracture of the floor of the orbit. During a surgical exploration of the orbital floor, the patient exhibited sudden symptoms of OCR. It was managed by withholding the surgery and administering atropine. The article also highlights the mechanism, types, incidence, and management of OCR in patients with maxillofacial trauma.