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The most common cause of congenital heart block (CHB) is neonatal lupus, an acquired autoimmune disease caused by transplacental transfer of maternal antibodies to the fetus. A full-term female neonate was admitted to neonatal intensive care unit for severe bradycardia with stable haemodynamics. The mother, showing no clinical symptoms or any particular history, was transferred to our tertiary centre for profound fetal bradycardia. At birth, the infant’s ECG showed a third-degree atrioventricular block and echocardiography was normal. Cardiac neonatal lupus was confirmed with positive maternal anti-Ro antibodies. Under close monitoring, the infant tolerated the bradycardia well (median 67 beats per minute (bpm)) and was discharged on day 6 of life. There was no indication for pacemaker, but she would be on regular follow-up with a paediatric cardiologist. This article holds an important insight as it is the first confirmed case of autoimmune CHB in Cambodia in which the mother’s antibody was found only after diagnosis on the neonate.

Asystole or bradycardia is a relatively uncommon side effect seen in patients undergoing endovascular embolization using dimethylsulfoxide based liquid embolic agents. We present a case of a patient who underwent dural arteriovenous fistula embolization and experienced bradycardia during Onyx injection but was stabilized and the procedure was completed successfully.

A 6-month-old girl presented to hospital via ambulance with a decreased conscious level (initial Glasgow Coma Scale of 3) and an abnormal breathing pattern described as diaphragmatic flutter. She then developed abnormal movements and continued to have episodes of fluctuating conscious levels so was transferred to a tertiary hospital paediatric intensive care unit for further investigation. During her 16-day stay in hospital, she continued to experience discrete episodes of drowsiness, bradycardia, unusual breathing patterns and abnormal movements which were associated with agitation, tachycardia, hypertension and insomnia. The patient underwent extensive investigation for her symptoms and, after some delay in waiting for initial results before considering a urine drug screen, she was ultimately found to have lisdexamfetamine and clonidine in her urine drug screen. Her symptoms subsequently resolved after her mother’s visits were restricted.

Thyroid hormones have an integral role in cardiac homeostasis, and hypothyroidism may be associated with impaired myocardial contractility, altered endothelial function, and blunted response to catecholamines. Herein, the case of a patient with undiagnosed severe hypothyroidism, who developed an acute myocardial infarction and cardiac arrest during sedation for bronchoscopy, is described. He required prolonged resuscitation, which included coronary catheterization and placement of an intra-aortic balloon pump. The resuscitation was noteworthy for blunted physiologic responses to large doses of epinephrine; in particular, persistent bradycardia without evidence of conduction abnormalities. On admission to the intensive care unit, he was hypothermic (31.4°C), bradycardic, and hypotensive. Laboratory investigations revealed profound hypothyroidism, and thyroid hormone replacement was initiated. Within hours of initiation of thyroid hormone replacement, the need for vasopressor support was reduced. He had a complete recovery and was discharged home neurologically intact. The authors of the present report believe that this favorable neurologic outcome could be attributed to efficient resuscitation, prompt coronary revascularization, and profound hypothermia likely related to a hypothyroidism-associated hypometabolic state.

A 9-year-old boy, diagnosed with double outlet right ventricle after birth, suffered sinus node dysfunction and non-sustained junctional tachycardia after an extracardiac total cavopulmonary connection (TCPC). Spontaneous atrial tachycardia appeared 3 years after an extracardiac TCPC. Sotalol was administered but the bradycardia was obvious. It was difficult to increase sotalol and atrial tachycardia was uncontrollable. Atrial tachycardia continued with symptoms; direct current (DC) cardioversion was frequently required. Five years after extracardiac TCPC, we implanted a pacemaker with atrial antitachycardia pacing (ATP) using epicardial leads. On day 2 post operation, wide QRS tachycardia appeared. Due to decreased blood pressure, DC cardioversion was immediately performed, but it recurred from atrial premature contraction. We judged this was atrial tachycardia with 1:1 atrioventricular conduction based on an intracardiac electrogram and it was terminated by burst atrial pacing from the pacemaker. After changing atrial pacing rate to 150 ppm, atrial tachycardia could be suppressed. Due to atrial pacing and increasing sotalol gradually, junctional tachycardia terminated spontaneously, and atrial tachycardia was not induced after pacemaker implantation. In conclusion, implantation of a pacemaker with ATP and intensification of antiarrhythmic drugs is an effective treatment strategy for pediatric patients with bradycardia-tachycardia syndrome after extracardiac TCPC.

BACKGROUND: Increased cardiorespiratory events with bradycardia and oxygen desaturation have been reported in very low birthweight (VLBW) infants following stressors such as immunizations. These events are difficult to quantify and may be mild. Our group developed an automated algorithm to analyze bedside monitor data from NICU patients for events with bradycardia and prolonged oxygen desaturation (BDs) and used this to compare BDs 24 hours before and after potentially stressful interventions. METHODS: We included VLBW infants from 2012–2017 with data available around at least one of four interventions: two-month immunizations, retinopathy of prematurity (ROP) examinations, ROP therapy, and inguinal hernia surgery. We used a validated algorithm to analyze electrocardiogram heart rate and pulse oximeter saturation data (HR, SpO2) to quantify BD events of HR

One of the major reasons of death worldwide is Cardiovascular diseases. One of its type is Arrhythmia in which normal rhythm of heart is varied due to damage in heart muscles and electrolyte imbalance. To study cardiovascular disease, Electrocardiogram (ECG) signal is used that plays a significant role in identifying Arrhythmia. By using a combination of Multivariate Empirical Mode Decomposition (MEMD) and Artificial Neural Network (ANN), a hybrid technique is proposed in this research work to detect and classify Arrhythmia. MEMD, a promising technique that is used nowadays for denoising of multichannel signals, is used in this work. Two main features, i.e., RR interval and Heart Rate are extracted from the ECG signal for the detection of Arrhythmia. Using these features, Arrhythmia is classified into Tachycardia and Bradycardia. Classification is done using pattern recognition of ANN in which Multilayer feed forward neural network is used and trained through Back Propagation Algorithm. Results that are achieved using proposed technique is compared with previous existing techniques as in 2016 (Discrete Wavelet Transform) DWT and ANN gave 87.01% and in 2018 (Empirical Mode Decomposition) EMD and (Linear Discriminant Analysis) LDA gave 87% accuracy. As compare to these techniques, the proposed technique results show that it is an efficient technique that gives better accuracy of 89.8%.

Background Cardiovascular sequelae of coronavirus disease 2019 (COVID-19) infection have been explored by clinicians and researchers all over the world. Objective The purpose of this study was to evaluate the incidence of atrioventricular block (AV) in patients hospitalized for COVID-19 and its association between in-hospital morbidity and mortality. Methods In-hospital electrocardiograms (ECGs) of 438 patients were compared with their prior or baseline ECGs to ascertain the development of new onset AV block. Patients who developed new AV blocks were then followed at 30 and 90 days post-discharge to check for resolution of AV block. Demographic characteristics, clinical characteristics, and complications during their hospital stay were evaluated. Major complications including respiratory failure requiring oxygen supplementation and mechanical ventilation, sepsis, deep vein thrombosis, elevated troponins, hospital and intensive care unit (ICU) length of stay, as well as death were compared between those who developed new onset AV blocks and those who did not. Results Based on our single center study, the incidence of new onset AV blocks among patients admitted for COVID-19 during the study period was 5.5 cases per 100 patients. New onset AV blocks were not associated with longer hospital and ICU length of stay, increased intubation rates, or increased mortality. Conclusion Although the development of a new onset AV block is most likely multifactorial and not solely due to COVID-19, it is still important for clinicians to be mindful about the possibility of developing symptomatic bradycardia and life-threatening arrhythmias in patients admitted for COVID-19. This can be achieved by appropriate rhythm monitoring in-patient but the need for a cardiac event monitor upon discharge is unlikely to be necessary. Careful history taking, including family and drug use history is also of great importance as emerging drug therapies for COVID-19 have potential arrhythmogenic effects., Graphical abstract Image, graphical abstract

Implantable loop recorders (ILRs) are effective in achieving symptom-rhythm correlation. Data on the diagnostic yield of ILRs, on nurse-led syncope clinics, and on nurse-led ILR implants are limited.We evaluated the safety and efficacy of our nurse-led syncope clinic and nurse-led ILR implants.A retrospective study of all consecutive patients undergoing nurse-led ILR implantations was performed between April 2016 and April 2018. Patients were referred from both nurse-led and physician-led clinics. Data were collected on baseline demographic characteristics, referral source, symptom-rhythm correlation, ILR findings, and subsequent changes to management. All ILRs were enrolled into remote monitoring with automatic arrhythmia detection, and all immediate (≤24 hours) ILR implant complications were recorded. Comparisons were made between nurse-led and physician-led clinics and subsequent outcomes.A total of 432 patients with an ILR were identified: 164 (38%) from nurse-led and 268 (62%) from physician-led clinics; 200 (46%) were women (mean age 66.5 ± 18.2 years; mean follow-up duration 28.9 ± 9.5 months). Primary ILR indications were syncope (n = 251 [58%]), presyncope (n = 33 [7%]), palpitation (n = 39 [9%]), cryptogenic stroke (n = 78 [18%]), and other reasons (n = 31 [7%]). No immediate ILR implant complications occurred. Overall, 156 patients (36%) had a change in management as a direct result of ILR findings, with no overall differences between nurse-led and physician-led clinics (35% vs 36%; P = .7). More patients had newly diagnosed atrial fibrillation in physician-led clinics (15% vs 7%; P = .01), and more patients had pacemaker implants for bradycardia in nurse-led clinics (23% vs 13%; P.01).Nurse-led ILR implantation was safe and effective. Nurse-led syncope clinics achieved good symptom-rhythm correlation with resultant significant changes to management in comparison to physician-led clinics. Larger prospective studies are needed to evaluate their longer-term impact.

Background: Heart failure (HF) patients with atrial fibrillation (AF) often have conduction system disorders, which may be worsened by β-blocker therapy.Objective: In a post hoc analysis we examined the prevalence of bradycardia and its association with adverse events (AEs) and failure to achieve target dose in the GENETIC-AF trial.Methods: Patients randomized to metoprolol (n = 125) or bucindolol (n = 131) entering 24-week efficacy follow-up and receiving study medication were evaluated. Bradycardia was defined as an electrocardiogram (ECG) heart rate (HR) Results: Mean HR in sinus rhythm (SR) was 62.6 ± 12.5 bpm for metoprolol and 68.3 ± 11.1 bpm for bucindolol (P < .0001), but in AF HRs were not different (87.5 bpm vs 89.7 bpm, respectively). Episodes per patient for bucindolol vs metoprolol were 0.82 vs 2.08 (P < .001) for bradycardia and 0.24 vs 0.57 for severe bradycardia (P < .001), with 98.9% of the episodes occurring in SR. Patients experiencing bradycardia had a 4.15-fold higher prevalence of study medication dose reduction (P Conclusion: In AF-prone HF patients bradycardia may limit the effectiveness of β blockers, and this property is agent-dependent.

We report a case of dengue shock syndrome complicated by clinically suspected acute myocarditis in pediatric patient at a limited-resources hospital in a rural area and review the literature. A 12-year-old boy who experienced dengue shock syndrome developed bradycardia on day 7th of illness. His electrocardiogram during the bradycardia showed sinus bradycardia with a rate of 50 beats per minute. Atropine sulfate and dobutamine, alongside supportive management, were administered. The patient recovered 4 days later. We found a total of seven articles involving pediatric patient with dengue illness and cardiac complications by PubMed search. Clinical manifestations of cardiac involvement in pediatric patient with dengue varied and were mostly transient from tachy-bradyarrhythmia, sinus node dysfunction, low blood pressure, decreased ejection fraction, lower cardiac output, and increased cardiac enzyme. Transient cardiac abnormality can be an important presentation, and physician should have high awareness of cardiac complication in dengue-affected pediatric patients to manage them accordingly.

BRASH (Bradycardia, Renal failure, Atrioventricular [AV]-node blocker medications, Shock, and Hyperkalemia), a novel syndrome, is a synergistic interaction between AV node blockers and hyperkalemia, resulting in bradycardia. We report a case of BRASH syndrome with marked bradycardia in a patient with End-Stage Renal Disease (ESRD) associated with synergistic interaction between mild hyperkalemia and AV node blockers. Anesthesiologists should be aware of these clinical features, in which ESRD patients with baseline mild hyperkalemia are particularly susceptible to bradycardia. This report will help in its early recognition as well as enable comprehensive and appropriate treatment strategies without further invasive therapy.

Objective To determine the effect of fentanyl on the minimum alveolar concentration of isoflurane (MACISO) and cardiovascular variables in dogs, and how the treatment of bradycardia affects them. Study design Prospective, randomized crossover-controlled trial. Animals A total of six male Beagle dogs weighing 9.9 ± 0.7 kg (mean ± standard deviation) and aged 13 months. Methods To each dog, two treatments were assigned on different days: fentanyl (FENTA) or fentanyl plus glycopyrrolate (FENTAglyco) to maintain heart rate (HR) between 100 and 132 beats minute−1. Determinations of MACISO were performed with 10 plasma fentanyl target concentrations ([Fenta]Target (0, 0.16, 0.32, 0.64, 1.25, 2.5, 5.0, 10.0, 20.0 and 40.0 ng mL−1) for FENTA and 5 [Fenta]Target (0, 1.25, 2.5, 5.0, 10.0 ng mL−1)) for FENTAglyco. During each MACISO determination, cardiovascular variables [mean arterial pressure (MAP), HR and cardiac index (CI)] were measured, and systemic vascular resistance index (SVRI) calculated. Pharmacodynamic models were used to describe the plasma fentanyl concentration [Fenta]–response relationship for the effect on MACISO and cardiovascular variables. A mixed-model analysis of variance followed by Dunnett’s or Tukey’s test, and the Bonferroni adjustment were used for comparisons within and between each treatment, respectively. Significance was set as p Results Fentanyl decreased MACISO by a maximum of 84%. The [Fenta] producing 50% decrease in MAC, HR and CI were 2.64, 3.65 and 4.30 ng mL−1 (typical values of population model), respectively. The prevention of fentanyl-mediated bradycardia caused no significant effect on MACISO, but increased HR, MAP and CI, and decreased SVRI when compared with isoflurane alone. Conclusions and clinical relevance Fentanyl caused a plasma concentration-dependent decrease in MACISO, HR and CI and an increase in SVRI. Cardiovascular improvements associated with fentanyl in isoflurane-anesthetized dogs only occurred when the fentanyl-mediated bradycardia was prevented.

Background : The optimal right ventricular (RV) pacing site during pacemaker implantation is still unclear due to left ventricular (LV) dyssynchrony by traditional RV pacing. His-bundle (HIS) pacing has achieved narrow QRS and maintained LV synchrony but high failure rate. RV septal pacing occasionally has QRS waveform with wide and narrow component in the early and late phase, respectively, and maintains LV synchrony, reflecting the normal conduction system. We aimed to define this QRS waveform as retrograde penetration pacing into the conduction system (RPP-CS) and compared its effect on LV synchrony as an alternative approach of HIS pacing. Methods and Results : We enrolled 42 patients with atrio ventricular block (AVB) or bradycardia atrial fibrillation (AF) requiring pacemaker implantation (RPP-CS, n = 27; no RPP-CS, n = 15). Baseline characteristics were similar between the groups. RPP-CS was observed in 96% and 26% of the RV septum and apex area, respectively. RPP-CS had a significantly shorter QRS width (p Conclusions : RPP-CS, especially with short QRS intervals (≤132 ms), had a high frequency of LV synchrony, maintained postoperative cardiac function, and may be an adequate first-line RV pacing site strategy for AVB or bradycardia AF as an alternative approach of HIS pacing.

Background: We review the efficacy and safety of dexmedetomidine and clonidine as perineural or systemic adjuvants for brachial plexus blocks (BPB). Methods: We included randomised controlled trials on upper limb surgery with BPBs in adults, comparing dexmedetomidine with clonidine or either drug with placebo. The primary outcome was duration of analgesia. Secondary outcomes included adverse and serious adverse events. The review was conducted using Cochrane standards, trial sequential analyses (TSA) and Grading of Recommendations Assessment, Development and Evaluation (GRADE). Results: We included 101 trials with 6248 patients. Overall, duration of analgesia was prolonged with both clonidine (176 min [TSA adj. 95% CI: 118, 205, p

Angina is a significant contributor to disability and impairment in quality of life in patients with chronic coronary syndromes (CCS). An elevated heart rate (HR) may trigger myocardial ischemia by increasing oxygen consumption and decreasing the diastolic time, compromising the coronary flow. HR-lowering strategies offer symptom control and prevent cardiovascular events in subgroups of patients with CCS. However, the best therapeutic approach to achieve the desired HR in patients with CCS can be challenging based on efficacy and tolerability. Guidelines usually propose β-blockers and/or non-dihydropyridine calcium channel blockers (CCB) for angina patients with elevated HR. Nonetheless, there is no clear evidence of greater antianginal efficacy of this strategy versus an alternative HR-lowering agent. Ivabradine reduces the HR by blocking the If current in the sinoatrial node without affecting myocardial contractility or vascular tone. The magnitude of the HR reduction by ivabradine is proportional to the initial HR, which decreases the risk of significant bradycardia. Ivabradine increases the diastolic time and the coronary flow reserve to a greater extent than β-blockers and favors collateralization, improving the regional blood flow. We present two clinical cases of patients with symptomatic CCS in whom HR control with ivabradine was fundamental for symptom control and improvement in left ventricular (LV) function. An earlier combination of ivabradine plus β-blockers would have provided more rapid symptom control and improved LV function in the first case. In the second case, the primary mechanism responsible for angina was most likely a coronary vasomotor abnormality, in which the use of β-blockers aggravated the discomfort. The combination of a dihydropyridine CCB plus ivabradine was highly influential in symptom control. Due to its effects beyond HR reduction and good tolerability, ivabradine should be considered an essential ally in managing patients with angina and high HR with or without LV dysfunction.

PURPOSE SharpSense™ technology is an upgradable software enhancement introduced to the Abbott Confirm Rx™ insertable cardiac monitor (ICM). This study aims to characterize the real-world performance of SharpSense algorithms by comparing device detected pause and bradycardia episodes before and after the SharpSense upgrade. METHODS Confirm Rx devices with at least 90 days monitoring each before and after SharpSense upgrade were included in the study. Bradycardia and pause detections and subcutaneous electrocardiograms (SECGs) within 90 days before and after the upgrade were extracted from Merlin.net™ patient care network for evaluation and adjudicated by expert adjudicators. RESULTS A total of 197 devices were included in the analysis. Devices were implanted for syncope (35.0%), atrial fibrillation (32.5%), cryptogenic stroke (16.8%), and other indications including palpitations (15.7%). The SharpSense upgrade significantly reduced the number of bradycardia detections by 86.8% and pause detections by 93.1%. In adjudicated SECGs, the upgrade significantly reduced false positive (FP) bradycardia episodes by 91.5% and FP pause episodes by 82.8%. The percentage of devices with at least one FP episode was reduced from 39 to 20% for bradycardia and from 52 to 35% for pause. The number of devices with FP rate greater than 1 episode per week was reduced from 23 to 8% for bradycardia and from 39 to 20% for pause. CONCLUSIONS In this real-world performance evaluation, the algorithms incorporated in SharpSense software upgrade in Confirm Rx ICMs substantially reduced false positive bradycardia and pause detections and the number of transmitted SECGs for clinic review.

Phenytoin is a known human teratogen with unknown etiology. Several mechanisms have been proposed including disturbances in folate metabolism, induction of embryonic hypoxia following phenytoin-induced bradycardia, free radical formation following re-oxygenation and phenytoin-induced maternal hyperglycemia. Using high frequency ultrasound, we demonstrated that phenytoin induced a dramatic decrease in the heart rate of embryos. This coincided with a moderate transient decrease in maternal heart rate and blood glucose levels. Embryonic heart rate had not fully recovered 24 h later in some embryos despite normal maternal physiological parameters. In a separate study, extent of hypoxia was measured using the marker pimonidazole. Phenytoin-exposed embryos did not demonstrate increased hypoxia compared to control embryos at 2, 4, 8 or 24 h dosing. Together our results show that phenytoin induces malformations as a result of a combination of insults: embryonic bradycardia, maternal bradycardia and maternal hyperglycemia. However, this does not appear to result in measurable embryonic hypoxia in our animal model.

The concentration dependenies of the chronotropic response and changes in blood supply to the isolated heart of 7-day-old newborn rats induced by application of α2-adrenergic receptor agonist clonidine hydrochloride in concentrations of 10-9-10-6 M were revealed. The minimum concentration of α2-adrenergic receptor agonist caused tachycardia, while higher concentrations led to bradycardia. The maximum effect manifesting in a decrease in coronary flow was recorded at the minimum concentration of the agonist, while the highest concentration had no effect on the coronary flow. When comparing these results with those obtained in control adult rats, we found that the most pronounced differences in the chronotropic effects were observed after addition of the minimum concentration of the α2-adrenergic receptor agonist: bradycardia in adult rats and tachycardia in newborns. The maximum differences in coronary flow parameters were observed after addition of α2-adrenergic receptor agonist in the maximum concentration that induced a two-phase response in adult rats and had no effect on the blood supply in newborns.

Aim: The importance of managing fetal arrhythmia has increased with advances in fetal echocardiography. We aimed to describe the incidence, types, clinical characteristics, treatments, and follow-ups of patients diagnosed with fetal arrhythmia in our center. Materials and Methods: Fetal echocardiographic examinations performed in our units between January 2016 and September 2019 were retrospectively evaluated. Fetal arrhythmias and their subtypes were identified using M-mode and Doppler echocardiography in all patients. Maternal age, gestational age, history of maternal or gestational pathology, diagnoses, and medications were recorded. Fetal arrhythmias were categorized into three main groups: 1) Irregular heart rhythm (ectopic beats), 2) Bradyarrhythmias: a ventricular rate less than 110 bpm; and 3) Tachyarrhythmias: a ventricular rate exceeding 180 bpm. Results: A total of 60 patients were diagnosed with fetal arrhythmia, corresponding to an overall incidence of 0.5%. The mean maternal and gestational age of those patients with fetal arrhythmia were 28.35 +/- 4.88 years and 31.03 +/- 5.94 weeks. One patient had maternal systemic disease, and four had concurrent congenital cardiac disease. Fetal tachycardia, bradycardia, and irregular heart rhythm were detected in 10 (16.6%), 8 (13.3%), and 42 (70%) patients, respectively. Conclusion: Fetal echocardiography represents the main diagnostic tool for prenatal evaluation of fetal arrhythmias, which have a variable prognosis depending on the type of arrhythmia. The most common fetal arrhythmia, the irregular heart rhythm, generally does not necessitate any treatment and resolves spontaneously. The treatment plan in patients should be based on etiology and fetal conditions.

Sinus node dysfunction (SND) encompasses a broad array of disturbances of sinus node or sinoatrial (SA) function that result in chronic or intermittent periods of slow or fast heart beating. Sinus node dysfunction may be the result of conditions that directly alter sinus node or SA structure, such as ischemic changes, fibrosis or infiltrative diseases, or extrinsic factors, such as drugs or autoimmune disturbances. In children and young adults, intrinsic SA disease has been most commonly associated with presumed direct sinus node damage due to previous atrial surgery, such as closure of atrial septal defects (ASDs), and most importantly, after atrial switch procedures for transposition of the great arteries. However, SND has been observed in patients with unoperated congenital heart disease and even in apparently normal children and adolescents. Thromboembolism is the single most important cause of mortality in SND. Its incidence ranges from 15% to 38%. Regarding therapy of SND, pacemaker therapy may be appropriate in some cases, drug suppression of arrhythmias in others, and both strategies may be required in many individuals. Anticoagulation is critical for treatment of many individuals with SND, particularly those with paroxysmal or persistent atrial fibrillation. In general, pacemaker therapy is indicated and has proven to be highly effective in patients with SND when bradyarrhythmia has been demonstrated to account for symptoms.

Objective To evaluate effectiveness of combinational use of dexmedetomidine and ketamine (DEX-KET) for pediatric procedural sedation or premedication. Methods Relevant studies were identified after a literature search in electronic databases and study selection was based on precise eligibility criteria. Meta-analyses of mean differences were performed to examine differences in sedation onset and recovery times between DEX-KET and comparators. Changes from baseline in heart rate (HR), respiratory rate, oxygen saturation, and mean arterial pressure (MAP), were pooled. Meta-analyses of proportions were performed to estimate incidence of adverse events. Results 15 studies (1087 patients) were included. Onset of sedation was significantly shorter in DEX-KET than in DEX group. HR declined in DEX-KET group from start (−3.5 beats per minute (BPM) [95% CI: −5.1, −1.9]) through midpoint (−7.2 BPM [95% CI: −12.1, −2.3]) and at end of sedation (−8.7 BPM [95% CI: −13.1, −4.4]). Decrease in HR after DEX administration at start was −11.6 BPM [95% CI: −16.0, −7.1] and remained consistent afterward. There was no change in MAP during DEX-KET sedation. However, after DEX administration, MAP decreased by −6.9 [95% CI: −10.4, −3.3] at start, −7.8 [95% CI: −11.4, −4.2] at middle, and by −6.6 [95% CI: −14.4, 1.1] at end of sedation. Incidence of hypotension was 3% [95% CI: 0, 9] in DEX-KET, 7% [95% CI: 2, 14] in DEX, and 0% [95% CI: 0, 2] in KET groups. Incidence of bradycardia was 2% [95% CI: 0, 6] with DEX-KET and 12% [95% CI: 5, 20] with DEX. Incidence of oxygen desaturation was 3% [95% CI: 0, 8] in DEX-KET, 2% [95% CI: 0, 6] in DEX, 12% [95% CI: 5, 20] in KET, and 13% [95% CI: 6, 21] in PROP-KET groups. MIDA-KET sedation had 13% [95% CI: 4, 25] incidence of tachycardia. Conclusions DEX-KET for pediatric sedation results in better sedation outcomes than DEX or KET by shortening onset of sedation and recovery while maintaining hemodynamic and respiratory stability with low incidence of adverse events. DEX sedation was associated with higher incidence of bradycardia. Higher incidence of oxygen desaturation was observed with KET and PROP-KET whereas MIDA-KET was associated with higher incidence of tachycardia.

Atrioventricular blocks may be caused by a variety of potentially reversible conditions, such as ischemic heart disease, electrolyte imbalances, medications, and infectious diseases. Such causes must be always ruled out to avoid unnecessary pacemaker implantation. Patient management and reversibility rates depend on the underlying cause. Careful patient history taking, monitoring of vital signs, electrocardiogram, and arterial blood gas analysis are crucial elements of the diagnostic workflow during the acute phase. Atrioventricular block recurrence after the reversal of the underlying cause may pose an indication for pacemaker implantation, because reversible conditions may actually unmask a preexistent conduction disorder.

BACKGROUND Acute cervical spinal cord injury (ACSCI) is commonly complicated by spinal shock, resulting in hemodynamic instability characterized by bradycardia and hypotension that can have fatal consequences. Current guidelines recommend the use of intravenous beta and dopamine agonists, such as norepinephrine and dopamine, respectively. We sought to determine whether enteral albuterol would be a safe and feasible treatment for bradycardia without an increase in the occurrence of known side effects of albuterol in patients with ACSCI. METHODS A retrospective review of patients with ACSCI admitted to an intensive care unit at a level I trauma center and treated with enteral albuterol was conducted. Patients were excluded for the following reasons: pure beta blocker use prior to injury, concurrent use of pacemaker, age of less than 18 years, or age more than 75 years. As part of the standard of care, all patients underwent mean arterial pressure (MAP) augmentation to reach a goal of greater than 85 mm Hg during the first 7 days post injury. All eligible patient charts were reviewed for demographic characteristics, daily minimum and maximum heart rate and MAP, and concomitant vasoactive medication use. Bradycardia and tachycardia were defined as heart rate less than 60 beats per minute (bpm) and greater than 100 bpm, respectively. Factors found to be associated with bradycardia on univariate analysis were entered into a multivariable generalized estimating equation analysis to determine factors independently associated with bradycardia during the study period. RESULTS There were 58 patients with cervical ASCI (age 45 ± 18 years, 76% men) admitted between January 1, 2016, and December 31, 2017, that met the study criteria. The mean time to initiation of albuterol was 1.5 ± 1.7 days post injury, with a duration of 9.3 ± 4.5 days and a mean daily dosage of 7.8 ± 4.5 mg. Bradycardia was observed in 136 of 766 patient days (17%). There were a few episodes of hyperglycemia (1%) and tachycardia (3%), but no episodes of hypokalemia. In a multivariable analysis, female sex (P = 0.006) and American Spinal Cord Injury Association grade A, B, or C (P

Background Left bundle branch (LBB) pacing is a novel pacing technique which may serve as an alternative to both right ventricular pacing for symptomatic bradycardia and cardiac resynchronisation therapy (CRT). A substantial amount of data is reported by relatively few, highly experienced centres. This study describes the first experience of LBB pacing in a high-volume device centre. Methods Success rates (i.e. the ability to achieve LBB pacing), electrophysiological parameters and complications at implant and up to 6 months of follow-up were prospectively assessed in 100 consecutive patients referred for various pacing indications. Results The mean age was 71 ± 11 years and 65% were male. Primary pacing indication was atrioventricular (AV) block in 40%, CRT in 42%, and sinus node dysfunction or refractory atrial fibrillation prior to AV node ablation in 9% each. Baseline left ventricular ejection fraction was p = ns). Mean left ventricular activation time (LVAT) during LBB pacing was 81 ms and paced QRS duration was 120 ± 19 ms. LBB capture threshold and R‑wave sense at implant was 0.74 ± 0.4 mV at 0.4 ms and 11.9 ± 5.9 V and remained stable at 6‑month follow-up. No complications occurred during implant or follow-up. Conclusion LBB pacing for bradycardia pacing and resynchronisation therapy can be easily adopted by experienced implanters, with favourable success rates and safety profile.

Background: Heart diseases are the leading causes of mortality and Congenital Heart Disease (CHD) is the most common birth defect reported worldwide. Objective: The aim of this study was to evaluate the incidence of arrhythmias and CHD and the association between the two, among infants and children reported to our center. Methods: This cross-sectional study included infants and children who were referred to Shahid Madani Hospital, Khorramabad. Electrocardiogram (ECG) was performed in these children to determine the type of arrhythmia and records were used to obtain demographic data and the data regarding CHD. Results : Of 200 children enrolled in the study, 10 children had arrhythmias, 12 had tachycardia, 5 had bradycardia, and 31 had congenital disease. Among children with arrhythmias, 1 had atrial fibrillation, 4 patients had paroxysmal supraventricular tachycardia, 1 person had right bundle branch block, 1 had ventricular tachycardia, 2 had premature ventricular contractions and 1 had junctional ectopic tachycardia. Of the 31 children with CHD, 9 patients were presented with small ventricular septal defect, 4 children had patent foramen ovale, 2 had pulmonary stenosis and 1 of the children had tetralogy of fallout, arterial and ventricular septal defects and transposition of greater arteries, respectively. Conclusion: We reported a positive correlation between the arrhythmias and CHD. A larger number of studies collecting focusing on different age groups are therefore required to verify our findings.

Aims The COVID‐19 pandemic resulted in a decrease in patients' follow‐up and interventions with cardiovascular disease. In Portugal, the consequences on emergent pacemaker implantation rates are largely unknown. We sought to analyze the impact of the COVID‐19 pandemic on emergent pacemaker implantation rate and patient profile. Methods We retrospectively reviewed the clinical profile of the 180 patients who had pacemakers implanted in our hospital in an emergent setting from March 18, 2020, to May 17, 2020 (“lockdown”) and May 19 to July 17, 2020 (“postlockdown”). This data was then directly compared to the homologous periods from the year before. Results Urgent pacemaker implantation rates during "lockdown" was lower than its homologous period (−23.7%), and cases in "postlockdown" were significantly increased (+106.9% vs. "lockdown"; +13.2% vs. May–July 2019). When comparing “lockdown” and “postlockdown,” there was a tendency for a higher number of temporary pacemaker use (p = .076). Patients during “lockdown” were 7.57 times more likely to present with hypotension/shock (odds ratio 7.57; p = .013). We also noted a higher tendency for hypotension on presentation during “lockdown” (p = .054) in comparison to 2019. In comparison to its homologous 2019 period, “postlockdown” saw more patients presenting with bradycardia (p = .026). No patients were admitted to the emergency department during "lockdown" for anomalies detected on ambulatory tests. Conclusion Our data show that the COVID‐19 pandemic had a real impact on urgent pacemaker implantation. Patients with bradyarrhythmias are at particular risk for severe complications and should seek medical care regardless of the pandemic.

PURPOSE Autonomic control of the heart is balanced by sympathetic and parasympathetic inputs. Excitation of both sympathetic and parasympathetic systems occurs concurrently during certain perturbations such as hypoxia, which stimulate carotid chemoreflex to drive ventilation. It is well established that the chemoreflex becomes sensitized throughout hypoxic exposure; however, whether progressive sensitization alters cardiac autonomic activity remains unknown. We sought to determine the duration of hypoxic exposure at high altitude necessary to unmask cardiac arrhythmias during instances of voluntary apnea. METHODS Measurements of steady-state chemoreflex drive (SS-CD), continuous electrocardiogram (ECG) and SpO2 (pulse oximetry) were collected in 22 participants on 1 day at low altitude (1045 m) and over eight consecutive days at high-altitude (3800 m). SS-CD was quantified as ventilation (L/min) over stimulus index (PETCO2/SpO2). RESULTS Bradycardia during apnea was greater at high altitude compared to low altitude for all days (p 50%) following Day 5 at high altitude. Changes in saturation during apnea and apnea duration did not affect the magnitude of bradycardia during apnea (ANCOVA; saturation, p = 0.15 and apnea duration, p = 0.988). Interestingly, the magnitude of bradycardia was correlated with the incidence of arrhythmia per day (r = 0.8; p = 0.004). CONCLUSION Our findings suggest that persistent hypoxia gradually increases vagal tone with time, indicated by augmented bradycardia during apnea and progressively increased the incidence of arrhythmia at high altitude.

A 10-year-old 466 kg mustang gelding presented to an equine referral hospital for surgical repair of nasal, frontal and lacrimal bone fractures from an unknown trauma. Surgical repair was performed under general anaesthesia, including a right-sided maxillary regional anaesthetic block with mepivacaine hydrochloride. Progressive hyperkalaemia was documented perianaesthetically (T-3 mins; 134 mins after induction; potassium 6.4 mmol/L (ref 3.5-5.1 mmol/L). Perianaesthetic bradycardia was attributed to alpha -2 agonist infusion administration, and other characteristic ECG changes (flattened P waves, narrow T waves of increased amplitude, prolonged QRS complex) were not documented. Asystole occurred 137 min after induction of anaesthesia; however, a review of the available literature suggests the degree of hyperkalaemia documented was unlikely to be the primary cause of asystole but may have been a contributing factor. It is hypothesised that a trigeminocardiac reflex was the primary contributory factor to asystole in the described case, and may represent a maxillomandibulocardiac reflex that has not been previously described in the horse.

Sleep apnea occurs when the upper airway repeatedly becomes blocked during sleep, reducing or entirely blocking airflow. This is referred to as obstructive sleep apnea. If the brain fails to provide the necessary impulses for breathing, the disease is known as central sleep apnea. Sleep apnea and other sleep breathing problems are a leading cause of medical, social, and occupational disability. Sleep apnea is also linked to pulmonary hypertension, cardiac arrhythmia and other neurocognitive effects, majority of individuals with sleep apnea go undetected, putting them at danger during surgery. It is critical to identify these patients so that relevant steps can be implemented as soon as possible. In this review article, we will discuss about sleep apnea issues and their possible causes. Keywords: Sleep apnea, Bradycardia, Tachycardia, Breathing, Hypercapnia

Cardiac pacemakers are an extremely effective treatment for bradycardia but can, however, cause desynchronization of ventricular contraction leading to cardiomyopathy. Pacing of the conduction system can prevent and even reverse desynchronization, which is impressively visible in echocardiography with speckle tracing. His' bundle and left bundle branch pacing requires a specific implantation technique, sheaths and leads which can achieve successful stimulation of the conduction system in up to 98% of cases. Data on conduction system pacing have been acquired in numerous studies but only a few randomized outcome studies. Therefore, in the current European guidelines His' bundle and left bundle branch pacing only have a low level recommendation. The guidelines recommend His' bundle pacing in patients in whom a coronary sinus lead cannot be implanted and in patients with permanent atrial fibrillation and planned atrioventricular (AV) node ablation for heart rate control. Additionally, conduction system pacing appears to be meaningful in patients with an AV block who require pacing of the ventricle for ≥20% of the time or who already show a slightly or moderately reduced left ventricular ejection fraction (36-50%). Even in patients scheduled for generator replacement who have developed a cardiac pacemaker-induced cardiomyopathy, the opportunity should not be missed to upgrade the system by implantation of a His' bundle electrode.

Background and Aims: During Cesarean section, hypotension occurs in the most of parturients, following spinal anesthesia. This prospective observational study was undertaken to determine the efficacy of two different Bolus Doses of Phenylephrine for Prevention of Spinal-Induced Hypotension during Cesarean Section. Materials and Methods: A total of 120 parturients undergoing cesarean section were divided into two groups of group A and group B with sixty in each group. Group A received phenylephrine 75 mcg IV bolus, while Group B received phenylephrine 100 mcg IV bolus, immediately after giving spinal anesthesia. For the next 20 minutes, systolic blood pressure (SBP), diastolic blood pressure (DSP), mean arterial pressure (MAP), and heart rate (HR) were recorded every 2 minutes, and APGAR scores at 1 and 5 minutes were recorded. Results: There was no difference between the two groups in terms of preventing hypotension, with 16.6% in Group A and 16.6% in Group B. In the first 2–6 minutes, however, the rise in systolic pressure in Group B was higher than in Group A. Group B (46.66 %) had a higher rate of bradycardia than Group A (25 %). Conclusion: Both phenylephrine dosages were equally effective in preventing hypotension following spinal anesthesia. However, Prophylactic bolus dose of phenylephrine 75 mcg was found to be effective for the management of spinal-induced hypotension and should be preferred over 100 mcg which causes significant bradycardia and reactive hypertension.

A 54-year-old male driver was injured in a car crash in which his front-side passenger died at the scene. The initial assessment indicated that he was conscious and able to recall the accident. His vital signs included blood pressure of 155/95 mm Hg, heart rate of 112 beats/min, and respiratory rate of 21 breaths/min, and he complained of stabbing retrosternal pain. A palpable sternal fracture with a tender contusion, a discrepancy between the blood pressures between the arms, and diminished femoral pulses were other findings. With a thoracic aortic pseudoaneurysm suspicion, the emergency physician maintained the patient's systolic blood pressure around 100 mm Hg and his heart rate less than 100 beats/min. Because of the need for urgent medical interventions, the emergency physician decided to transport him by air to the nearest advanced trauma center. After accordance with the trauma center and the air medical crew, the air transportation began. The patient subsequently decompensated with bradycardia and hypotension to cardiac arrest, for which 30 minutes of cardiopulmonary resuscitation unfortunately proved unsuccessful. The forensic report indicated an aortic pseudoaneurysm rupture of the proximal descending aorta with a massive hematoma that was a possible cause of death.

Learning objectives The aim of cardiac resynchronisation therapy (CRT) is to improve cardiac function by delivering more physiological cardiac activation to patients with conduction system disease. The most widely investigated method for delivering CRT is biventricular pacing (BiV-CRT). Multiple randomised control trials (RCTs) have found BiV-CRT improves outcomes when it is delivered to patients with heart failure, reduced ejection fraction (EF) and prolonged QRS duration.1–3 The majority of patients included in RCTs assessing BiV-CRT had left bundle branch block (LBBB), were in sinus rhythm, New York Heart Assocation (NYHA) class II or greater and had an EF ≤35%. BiV-CRT is also used as an alternative to right ventricular (RV) pacing in patients who have ventricular impairment and require a high percentage of ventricular pacing.4 Understanding the mechanism through which BiV-CRT delivers its beneficial effects is useful when considering patient selection. ### Improving ventricular electrical dyssynchrony When a patient develops LBBB, this prolongs left ventricular (LV) activation time and produces a non-physiological LV activation pattern. These changes result in less efficient contraction and reduced cardiac output.5 BiV pacing aims to deliver more effective ventricular activation by pacing the left and right ventricles. Ventricular activation occurs via cell-to-cell conduction with activation wavefronts originating from the two pacing sites. The activation time during BiV pacing is typically longer than occurs during activation via the intact conduction system and is relatively constant regardless of intrinsic activation.6 The potential for BiV pacing to deliver improvements in ventricular activation time is dependent on the presenting (intrinsic) conduction delay. A …

Introduction Anaplastic Lymphoma Kinase (ALK) inhibitors have revolutionized the treatment of advanced ALK-positive non-small cell lung cancer (NSCLC), improving progression-free survival. Bradycardia is a potential adverse effect of these agents. We aimed to determine the risk of bradycardia associated with ALK inhibitors in patients with advanced NSCLC. Materials and methods We conducted a systematic search of MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, National clinical trial registry, and Web of Science Core Collection. We included all randomized controlled trials in which an ALK-inhibitor was compared with another ALK-inhibitor or standard chemotherapy. Meta-analyses were conducted to evaluate the pooled incidence rates of bradycardia and dizziness using fixed effect models. Results The pooled incidence of bradycardia among 1737 individuals prescribed ALK inhibitors was 8% during a mean follow-up of 1.26 years. Crizotinib led to more bradycardia than standard chemotherapy (relative risk, RR 24.68, 95% CI 7.11–85.), while no difference was seen between crizotinib and alectinib (RR 1.12, 95% CI 0.79–1.59). The next-generation ALK inhibitors alectinib, brigatinib and lorlatinib combined resulted in a similar rate of bradycardia when compared to crizotinib (RR 0.77, 95% CI 0.57–1.04). All ALK inhibitors (as an aggregate) caused more dizziness (as a potential symptom of bradycardia) than standard chemotherapy (RR 1.88, 95% CI 1.44–2.44). Conclusion: Crizotinib for the treatment of NSCLC is associated with a higher risk for bradycardia compared to standard chemotherapy. There is no evidence of a difference in bradycardia risk between crizotinib and newer ALK inhibitors.

Background The use of less invasive surfactant administration (LISA)/minimally invasive surfactant therapy (MIST) has increased due to its potential advantage over traditional surfactant delivery methods through an endotracheal tube. Known complications for this procedure include failure of the first attempt at insertion, desaturation, and bradycardia. To the best of our knowledge, this is the first reported case of pneumomediastinum and subcutaneous emphysema following LISA. Case presentation A preterm newborn born at 27 weeks of gestation presented with respiratory distress syndrome requiring surfactant replacement. LISA using the Hobart method was completed. There was a report of procedural difficulty related to increased resistance to insertion of the 16G angiocath. The newborn was subsequently noted to have subcutaneous emphysema over the anterior aspect of the neck and substantial pneumomediastinum on radiological assessment. Associated complications included hypotension requiring inotropic support. The newborn was successfully managed conservatively, with complete resolution of the air leak. Conclusions Upper airway injury leading to air leak syndrome is a rare complication of the Hobart method for LISA. Awareness of such procedural complications is important as the use of the LISA method increases.

Objectives To investigate the extent of vatinoxan distribution into sheep brain, and whether vatinoxan influences brain concentrations of xylazine; and to examine the utility of cerebrospinal fluid (CSF) as a surrogate of brain tissue concentrations for vatinoxan and xylazine. Study design Randomised, blinded, experimental study. Animals A total of 14 adult female sheep. Methods Sheep were randomly allocated into two equal groups and premeditated with either intravenous (IV) vatinoxan (750 mu g kg(-1), VX) or saline (SX) administered 10 minutes before IV xylazine (500 mu g kg(-1)). Sedation was subjectively assessed at selected intervals before and after treatments. At 10 minutes after xylazine administration, a venous blood sample was collected and the sheep were immediately euthanised with IV pentobarbital (100 mg kg(-1)). Plasma, CSF and brain tissues were harvested, and concentrations of vatinoxan and xylazine were quantified using liquid chromatography-tandem mass spectrometry. Drug ratios were then calculated and the data were analysed as appropriate. Results The brain-to-plasma and CSF-to-plasma ratios of vatinoxan were 0.06 +/- 0.013 and 0.05 +/- 0.01 (mean +/- standard deviation), respectively. Xylazine brain concentrations were not significantly different (835 +/- 262 versus 1029 +/- 297 ng g(-1) in groups VX and SX, respectively) and were approximately 15-fold higher than those in plasma. The CSF-to-brain ratio of vatinoxan was 0.8 +/- 0.2, whereas xylazine concentrations in the brain were approximately 17-fold greater than those in CSF, with and without vatinoxan. Conclusions and clinical relevance Vatinoxan did not significantly affect sedation with xylazine or the concentrations of xylazine in the brain. CSF is not a good predictor of xylazine concentrations in the brain, whereas vatinoxan concentrations were concordant between the brain and CSF, using the dosages in this study.

Objective : Rapid increase in intracranial pressure (ICP) can result in hypertension, bradycardia and apnea, referred to as the Cushing phenomenon. During decompressive craniectomy (DC), rapid ICP decreases can cause changes in mean atrial blood pressure (mABP) and heart rate (HR), which may be an indicator of intact autoregulation and vasomotor reflex.Methods : A total of 82 patients who underwent DC due to traumatic brain injury (42 cases), hypertensive intracerebral hematoma (19 cases), or major infarction (21 cases) were included in this prospective study. Simultaneous ICP, mABP, and HR changes were monitored in one minute intervals during, prior to and 5–10 minutes following the DC.Results : After DC, the ICP decreased from 38.1±16.3 mmHg to 9.5±14.2 mmHg (p

We present the case of a woman who developed presumed spontaneous coronary artery dissection of a septal branch. She later developed high-grade atrioventricular block that led to a diagnosis of cardiac sarcoidosis involving the interventricular septum. This case illustrates a rare and challenging presentation of cardiac sarcoidosis. (Level of Difficulty: Beginner.), Central Illustration

Hypotension is a common adverse effect seen after spinal anesthesia. In recent literature the use of 5-HT3 receptor antagonists has been proposed to prevent spinal anesthesia induced hypotension (SAIH). We present the use of granisetron in several cases as prevention strategy for SAIH in our center. All 10 eligible subjects received 3 mg granisetron diluted in 10 cc normal saline 5 minutes prior to spinal anesthesia, on patients who undergone non-obstetric procedure. Eight patients showed good response without evidence of hypotension, while the other two patients had hypotension managed well with ephedrine. As many as 9 patients had no bradycardia, while shivering was noted in 3 patients. All patients didn’t suffer from nausea/vomiting, due to its effectiveness of granisetron acts as antiemetic agents. Granisetron, has great affinity specifically for 5-HT3 receptor. It blocked the Bezold Jarisch Reflex (BJR) activation that will lead to hypotension and bradycardia. In a nutshell, granisetron has shown its potential as a prevention strategy for hypotension after spinal anesthesia in the majority of our cases above. Keywords: Hypotension, Spinal anesthesia, granisetron, 5-HT3, BJR.

Background His-Purkinje conduction system pacing (HPCSP) has emerged as an effective alternative to overcome the limitations of right ventricular pacing (RVP) via physiological left ventricular activation, but there remains a paucity of comparative information for His bundle pacing (HBP) and left bundle branch pacing (LBBP). Methods A Bayesian random-effects network analysis was conducted to compare the relative effects of HBP, LBBP, and RVP in patients with bradycardia and conduction disorders. PubMed, Embase, Cochrane Library, and Web of Science were systematically searched from database inception until 21 September 2021. Results Twenty-eight studies involving 4,160 patients were included in this meta-analysis. LBBP significantly improved success rate, pacing threshold, pacing impedance, and R-wave amplitude compared with HBP. LBBP also demonstrated a non-significant trend towards superior outcomes of lead complications, heart failure hospitalization, atrial fibrillation, and all-cause death. However, HBP was associated with significantly shorter paced QRS duration relative to LBBP. Despite higher success rate, shorter procedure/fluoroscopy duration, and fewer lead complications, patients receiving RVP were more likely to experience reduced left ventricular ejection fraction, longer paced QRS duration, and higher rates of heart failure hospitalization than those receiving HPCSP. No statistical differences were observed in the remaining outcome measures. Conclusions This network meta-analysis demonstrates the efficacy and safety of HPCSP for the treatment of bradycardia and conduction disorders, with differences in pacing parameters, electrophysiology characteristics, and clinical outcomes between HBP and LBBP. Larger-scale, long-term comparative studies are warranted for further verification. This article is protected by copyright. All rights reserved.

Background Ketamine has seen increased use for sedation in the intensive care unit. In contrast to propofol or dexmedetomidine, ketamine may provide a positive effect on hemodynamics. Objective The objective of this study was to compare the development of clinically significant hypotension or bradycardia (ie, negative hemodynamic event) between critically ill adults receiving sedation with ketamine and either propofol or dexmedetomidine. Methods This was a retrospective cohort study of adults admitted to an intensive care unit at an academic medical center between January 2016 and January 2021. Results Patients in the ketamine group (n = 78) had significantly less clinically significant hypotension or bradycardia compared with those receiving propofol or dexmedetomidine (n = 156) (34.6% vs 63.5%; P < 0.001). Patients receiving ketamine also experienced smaller degree of hypotension observed by percent decrease in mean arterial pressure (25.3% [17.4] vs 33.8% [14.5]; P < 0.001) and absolute reduction in systolic blood pressure (26.5 [23.8] vs 42.0 [37.8] mm Hg; P < 0.001) and bradycardia (15.5 [24.3] vs 32.0 [23.0] reduction in beats per minute; P < 0.001). In multivariate logistic regression modeling, receipt of propofol or dexmedetomidine was the only independent predictor of a negative hemodynamic event (odds ratio [OR]: 3.3, 95% confidence interval [CI], 1.7 to 6.1; P < 0.001). Conclusion and Relevance Ketamine was associated with less clinically relevant hypotension or bradycardia when compared with propofol or dexmedetomidine, in addition to a smaller absolute decrease in hemodynamic parameters. The clinical significance of these findings requires further investigation.

Cardiac complications following snakebites are uncommon but fatal. Here, we discuss a case of a snakebite that led to acute myocardial infarction (AMI). Forty-five-year-old male presented to the emergency room with snakebite on the right middle finger. He was given symptomatic treatment and admitted for observation. His vital signs and initial investigations were normal except for the white blood count that was high. During observation, he developed vomiting and bradycardia. He was diagnosed with a right bundle branch block on ECG. The patient developed chest pain after a few hours and was diagnosed with AMI on ECG. The toxicology team started antivenom therapy. His troponin kept rising initially but later started coming down without percutaneous intervention (PCI). He was treated successfully with antivenom therapy and discharged.

For the first time, studies have been conducted to study the reaction of animal heart rate to various modes of motor activity after a traumatic brain injury. It was revealed that on the first day after modeling an open head injury in rats of all age groups, a pronounced increase in heart rate was observed. In this case, the smallest heart rate response to brain injury is observed in animals of immature age. It was found that the implementation of systematic dynamic exercises by animals of mature and preschool age after modeling a craniocerebral injury contributes to a significant decrease in heart rate. A more pronounced formation of training bradycardia is observed in immature animals. It was revealed that limiting motor activity and performing isometric exercises after a traumatic brain injury maintain heart rate at an increased level in all age groups of animals and significantly inhibits the natural, age-related decrease in heart rate in immature animals.

Introduction: Vaginal hysterectomy Surgery with long acting local anaesthetic like bupivacaine still requires higher doses of analgesics in the post-operative period. Dexmedetomidine is highly selective ?adrenoreceptor agonist and sympatholytic drug is a useful adjunct drug in patients undergoing vaginal hysterectomy under continuous spinal epidural block (CSE). We sought to study duration of perioperative analgesia, observe the intra-operative and post-operative hemodynamic changes and post-operative sedation effect of dexmedetomidine. Materials and Methods : The study groups were divided as Group D (study group) administered 1 µg/kg Dexmedetomidine and Group C (control group) administered 0.9% saline drip at the rate of 1ml/kg. Results: Dexmedetomidine group had prolonged duration of sensory blockade, duration for 2 dermatomal regression of sensory blockade and the duration for motor block regression to Modified Bromage scale 0. This group had prolonged duration of Time to first request for rescue analgesic.14% patients required mephentermine for management of hypotension. Intraoperative diastolic blood pressure (DBP) was lower in study group while Intraoperative Systolic blood pressure (SBP) was comparable in both the groups. Conclusions: Intravenous dexmedetomidine significantly decreases the heart rate and is associated with higher incidence of bradycardia. It is effective in providing postoperative analgesia and in preventing postoperative shivering with reduced incidence of postoperative nausea and vomiting. Keywords: Dexmedetomidine, Bupivacaine, Modified ramsay sedation score.

Case report of patient with bradycardia as a complication of VNS therapy and psychiatric worsening after turning VNS off.

Background: Caesarean section was the first obstetrical operation that saves the life of the baby when normal delivery fails. Spinal anaesthesia is the most appropriate method for caesarean section. But hypotension is the most common side effect of it in patient with pregnant uterus. Aims: To compare the vasopressor effects of ephedrine and phenylephrine in ameliorating hypotension in elective caesarean delivery receiving crystalloid coloading, during intrathecal bupivacaine injection. Materials and Methods: Study participants were randomly divided into two groups of 50 patients each. After subarachnoid block, all the parturients were given rapid administration of ringer lactate solution 20ml/kg, during the initial 5 minutes of surgery the parameters such as oxygen saturation, blood pressure and pulse rate recorded for every one minute followed by every five minutes until the completion of the surgery. The incidence of hypotension, bradycardia, nausea/vomiting, block height and requirements of vasopressor (ephedrine and phenylephrine) were recorded. Apgar score, and blood sample from umbilical cord was taken and sent for blood gas analyses to determine the neonatal outcome. Results: Vasopressor consumption was more in phenylephrine group (92±112 µg) compared to ephedrine group (4.8±5.5 mg) which was statistically significant p=0.0001. The neonatal outcome was statistically significant regarding umbilical cord pH (Group E-7.2±0.06 and Group P-7.37±0.04 with p=0.002) but clinically no true fetal acidosis in either groups and no significant changes regarding Apgar score in the two groups. Conclusion: Thus we conclude that that ephedrine 6 mg and phenylephrine 100 µg does not differ in their efficacy to manage hypotension during spinal anaesthesia for caesarean delivery. However, maternal bradycardia was more in the phenylephrine group with equal incidence of fetal acidosis in the study groups. Keywords: Hypotension, Ephedrine, Phenylephrine, Spinal anesthesia.

Corona disease 2019 (COVID-19) pandemic continues to spread around the world with no efficacious treatment. Intravenous remdesivir is the only authorized drug for treatment of COVID-19 disease under an Emergency Use Authorization. Remdesivir is a 1′-cyano-substituted adenosine nucleotide prodrug which inhibits viral RNA synthesis. This metabolite is an adenosine analog but with a significantly longer half-life than adenosine. Adenosine is a powerful vasodilator that can cause profound hypotension which is followed by the compensatory release of catecholamines. It can also shorten atrial action potential and refractoriness and lead to atrial fibrillation (AF). These effects may also occur in ventricular cells and predispose patients to ventricular fibrillation. Remdesivir can also induce significant cytotoxic effects in cardiomyocytes that is considerably worse than chloroquine cardiotoxic effects. Remdesivir-induced cardiotoxicity is due to its binding to human mitochondrial RNA polymerase. On the other hand, remdesivir can increase field potential duration with decreased Na+ peak amplitudes and spontaneous beating rates in a dose-dependent manner that might induce prolonged QT interval and torsade de point. There are some reports of sinus bradycardia, hypotension, T-wave abnormalities, AF, and a prolonged QT interval and few cases of cardiac arrest and complete heat block following remdesivir infusion. It seems remdesivir have some cardiotoxic and proarrhythmic effects that are especially more pronounced in patients with previous cardiovascular diseases. The current safety profile of remdesivir is still not completely known and further prospective clinical trials are needed to assess its safety profile and potential adverse cardiovascular effects.

Objective:To evaluate pre-operative implications, anesthetic management and post-operative anesthetic concerns in patientswith co-morbid diseases undergoing ambulatory laparoscopic cholecystectomy under general anesthesia. Study Design and setting:Retrospective study was conducted at Rawal Institute of Health Sciences, Islamabad from 8thOct 2017 to 5th Nov 2018. Methodology:Total one hundred and twelve patients were placed in American society of Anaesthesiologist (ASA) classII, III & IV (medically optimized) on pre-operative evaluation for ambulatory laparoscopic cholecystectomy. Generalanesthesia was administered with co-induction (nalbuphine 0.1mg/kg plus midazolam 0.01mg/kg) tracheal intubationfacilitated by 0.15mg/kg cis-atracurium. Post-operatively on clinical status evaluation and Post Anesthesia Discharge score,patients were shifted to respective ward /intensive care. Statistical analysis was done by SPSS v.21. Results:Pre-operatively medical and cardiologist evaluation was taken in 34(30.35%) and 42(37.5%) cases respectivelywhereas consultant anesthesiologist reviewed all cases. In study single case was converted to open method due to mirrizisyndrome and adhesions creating difficult laparoscopic dissection in 9(8.03%) of cases. Post-operatively in single caseatrial fibrillation with fast ventricular response noted followed by sudden bradycardia, managed and sinus rhythm restored,whereas in other case of ischemic heart disease with viral respiratory infection, needed ventilatory support after 2 hoursdue to respiratory distress and weaned off after 24hrs. In the study 76(67.9%) cases were shifted post-operatively to surgical ward and 36 cases (32.1%) needed intensive care treatment. Conclusion:Laparoscopic cholecystectomy in patients with co-morbid states requires balanced anesthetic technique considering consequences of pneumoperitoneum to decrease morbidity.