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Cureus Apr 2024Bradycardia, renal failure, atrioventricular nodal blockade, shock, and hyperkalemia syndrome is an underrecognized phenomenon in which renal injury leads to...
Bradycardia, renal failure, atrioventricular nodal blockade, shock, and hyperkalemia syndrome is an underrecognized phenomenon in which renal injury leads to hyperkalemia and inadequate clearance of atrioventricular nodal-blocking agents. The compounding effect of both insults can lead to a bradyarrhythmia that, in severe cases, can rapidly progress to cardiogenic shock. The degree of resulting pathology is usually out of proportion to either insulting agent given that there is a synergistic effect. Treatment strategies for this condition are not entirely clear, but it appears as if these patients often do not warrant aggressive interventions and can be managed medically. We report two cases with early recognition and simple medical management with resulting favorable outcomes.
PubMed: 38800148
DOI: 10.7759/cureus.58900 -
HeartRhythm Case Reports May 2024
PubMed: 38799602
DOI: 10.1016/j.hrcr.2024.02.016 -
JFMS Open Reports 2024A 1-year-old male neutered domestic shorthair cat presented on an emergency basis with clinical signs suspected to be secondary to organophosphate (OP) toxicity. The...
CASE SUMMARY
A 1-year-old male neutered domestic shorthair cat presented on an emergency basis with clinical signs suspected to be secondary to organophosphate (OP) toxicity. The control of clinical abnormalities (bradycardia, obtundation, tachypnea, anorexia) was achieved using high-dose continuous rate intravenous infusion (CRI) of atropine sulfate (maximum rate 0.1 mg/kg/h). After 5 days of hospitalization, the patient made a full clinical recovery without the development of atropine toxicity, intermediate syndrome or delayed polyneuropathy at 4 weeks after discharge.
RELEVANCE AND NOVEL INFORMATION
Treatment of OP toxicity in cats is sparsely reported in veterinary literature. Current standards of treatment and published protocols recommend the use of atropine sulfate as intermittent boluses for the treatment of muscarinic signs of toxicity; however, there is a paucity of information regarding the safety and efficacy of atropine sulfate as a CRI for severe toxicosis as described in humans. This report includes the first published case using such a treatment protocol in a cat.
PubMed: 38799116
DOI: 10.1177/20551169241249637 -
Antibiotics (Basel, Switzerland) Apr 2024Early-onset sepsis (EOS) is a rare but profoundly serious bacterial infection. Neonates at risk of EOS are often treated with antibiotics. The start of empiric...
Early-onset sepsis (EOS) is a rare but profoundly serious bacterial infection. Neonates at risk of EOS are often treated with antibiotics. The start of empiric antibiotic therapy can successfully be reduced by the implementation of the EOS calculator. However, once started, antibiotic therapy is often continued despite a negative blood culture. To decrease the burden of antibiotic therapy, it is necessary to know whether the clinician's reasons are based on objective factors. Therefore, we performed a retrospective single-centre cohort study to identify the factors associated with prolongation of antibiotic therapy in neonates with suspected EOS but a negative blood culture. Maternal, clinical, and laboratory data of neonates with a gestational age of ≥32 weeks, admitted between January 2019 and June 2021, were collected. Among neonates with a negative blood culture, we compared neonates with prolonged (≥3 days) to neonates with discontinued (<3 days) antibiotic therapy. The clinician's reported reasons for prolonging therapy were explored. Blood cultures were positive in 4/146 (2.7%), negative in 131/146 (89.7%), and not obtained in 11/146 (7.5%) of the neonates. The incidence of EOS was 0.7 per 1000 neonates. Of the 131 neonates with a negative blood culture, 47 neonates (35.9%) received prolonged antibiotic therapy. In the prolonged group, the mean gestational age was higher (38.9 versus 36.8 weeks), and spontaneous preterm birth was less prevalent (21.3% versus 53.6%). Prolonged treatment was associated with late onset of respiratory distress, respiratory rate, hypoxia, apnoea and bradycardia, pale appearance, behavioural change, and elevated CRP levels. The most reported reasons were clinical appearance (38.3%), elevated CRP levels (36.2%), and skin colour (10.6%). Prolonging empiric antibiotic therapy despite a negative blood culture is common in suspected EOS. Clinical signs associated with prolongation are uncommon and the reported reasons for prolongation contain subjective assessments and arbitrary interpretations that are not supported by the guideline recommendations as arguments for prolonged therapy.
PubMed: 38786117
DOI: 10.3390/antibiotics13050388 -
Biosensors Apr 2024Zebrafish larvae have emerged as a valuable model for studying heart physiology and pathophysiology, as well as for drug discovery, in part thanks to its transparency,...
Zebrafish larvae have emerged as a valuable model for studying heart physiology and pathophysiology, as well as for drug discovery, in part thanks to its transparency, which simplifies microscopy. However, in fluorescence-based optical mapping, the beating of the heart results in motion artifacts. Two approaches have been employed to eliminate heart motion during calcium or voltage mapping in zebrafish larvae: the knockdown of cardiac troponin T2A and the use of myosin inhibitors. However, these methods disrupt the mechano-electric and mechano-mechanic coupling mechanisms. We have used ratiometric genetically encoded biosensors to image calcium in the beating heart of intact zebrafish larvae because ratiometric quantification corrects for motion artifacts. In this study, we found that halting heart motion by genetic means (injection of morpholino) or chemical tools (incubation with -aminoblebbistatin) leads to bradycardia, and increases calcium levels and the size of the calcium transients, likely by abolishing a feedback mechanism that connects contraction with calcium regulation. These outcomes were not influenced by the calcium-binding domain of the gene-encoded biosensors employed, as biosensors with a modified troponin C (Twitch-4), calmodulin (mCyRFP1-GCaMP6f), or the photoprotein aequorin (GFP-aequorin) all yielded similar results. Cardiac contraction appears to be an important regulator of systolic and diastolic Ca levels, and of the heart rate.
Topics: Animals; Zebrafish; Calcium; Biosensing Techniques; Myocardial Contraction; Larva; Heart; Troponin T; Zebrafish Proteins; Troponin C
PubMed: 38785693
DOI: 10.3390/bios14050219 -
Frontiers in Toxicology 2024The association between Δ8-tetrahydrocannabinol (THC) and cardiac dysrhythmia has not been well described in children. Asystole, while consistent with reports of severe...
INTRODUCTION
The association between Δ8-tetrahydrocannabinol (THC) and cardiac dysrhythmia has not been well described in children. Asystole, while consistent with reports of severe bradycardia and apnea in children, is uncommonly described in the current literature. We present the first pediatric case of asystole and apnea following THC ingestion.
CASE
A 7-year-old male presented to the emergency department (ED) after his mother noticed he was lethargic 3-4 h after accidental ingestion of five 15 mg (total of 75 mg) Δ8-THC gummies. Upon arrival, he was vitally stable and well-appearing. He received maintenance intravenous fluids. Approximately 7 h after initial ingestion, he experienced a >15-s episode of asystole and apnea on telemetry requiring sternal rub to awaken. This was followed by bradycardia (60 beats per minute range) which resolved with 0.1 mg glycopyrrolate. He was admitted to the PICU, drowsy but arousable with stable vitals. After an uneventful 24-h (post-ingestion) PICU observation, he was discharged home in stable condition.
DISCUSSION
To our knowledge, this is the first reported pediatric case of THC-induced asystole. The etiology of asystole may be attributed to direct vagal stimulation of THC or respiratory depression. The typical recommended observation time after potential toxicity is 3-6 h after children have returned to their physiological and behavioral baseline. Our patient was clinically stable with no concern for respiratory depression or cardiac dysrhythmia yet experienced an asystolic pause with apnea 7 h after initial ingestion.
CONCLUSION
Our case demonstrates that asystole and apnea may occur in pediatric patients following large THC ingestions and those symptoms can appear late outside of the currently recommended observation period.
PubMed: 38784384
DOI: 10.3389/ftox.2024.1371651 -
Obstetric Medicine Jun 2024Unlike tachyarrhythmias, which are common in pregnancy, there is a paucity of data regarding maternal bradycardias. Our objective was to describe the characteristics,...
BACKGROUND
Unlike tachyarrhythmias, which are common in pregnancy, there is a paucity of data regarding maternal bradycardias. Our objective was to describe the characteristics, associated conditions, and prognosis of women who develop bradycardia post-partum.
METHOD
We conducted a retrospective chart review of patients referred to the Obstetrical Medicine service at British Columbia Women's Hospital from January 2012 to May 2020 for post-partum maternal bradycardia.
RESULTS
Twenty-four patients with post-partum bradycardia were included (age 34.2 ± 4.8 years; heart rate 40.4 ± 8.1 beats per minute; blood pressure 131/72 mm Hg). Sinus bradycardia (79.2%) was the most common rhythm. Dyspnea (29.4%) and chest pain (23.5%) were common symptoms. Mean time to resolution of bradycardia was 3.6 ± 3.8 days. Associated conditions potentially explaining the bradycardia were preeclampsia (54.1%), underlying (16.7%), medications (8.3%), and neuraxial anesthesia (8.3%).
CONCLUSIONS
Maternal bradycardia is an uncommon condition complicating the post-partum period, that is generally self-limiting, with the majority only require clinical observation.
PubMed: 38784194
DOI: 10.1177/1753495X231178407 -
Journal of Cardiothoracic Surgery May 2024There is little literature on the use of temporary pacemakers in children with fulminant myocarditis. Therefore, we summarized the use of temporary cardiac pacemakers in...
BACKGROUND
There is little literature on the use of temporary pacemakers in children with fulminant myocarditis. Therefore, we summarized the use of temporary cardiac pacemakers in children with fulminant myocarditis in our hospital.
METHODS
The clinical data of children with fulminant myocarditis treated with temporary pacemakers in Wuhan Children's Hospital from January 2017 to May 2022 were retrospectively analyzed.
RESULTS
A total of 6 children were enrolled in the study, including 4 boys and 2 girls, with a median age of 50 months and a median weight of 15 kg. The average time from admission to pacemaker placement was 2.75 ± 0.4 h. The electrocardiogram showed that all 6 children had third-degree atrioventricular block (III°AVB). The initial pacing voltage, the sensory sensitivity of the ventricle and the pacing frequency were set to 5-10 mV, 5 V and 100-120 bpm respectively. The sinus rhythm was recovered in 5 patients within 61 h (17-134) h, and the median time of using temporary pacemaker was 132 h (63-445) h. One of the children had persistent III°AVB after the temporary pacemaker. With parental consent, the child was fitted with a permanent pacemaker on the 12th day of his illness.
CONCLUSIONS
When fulminant myocarditis leads to severe bradycardia or atrioventricular block in children, temporary pacemakers have the characteristics of high safety to improve the heart function.
Topics: Humans; Myocarditis; Male; Female; Pacemaker, Artificial; Child, Preschool; Retrospective Studies; Child; Atrioventricular Block; Infant; Electrocardiography; Cardiac Pacing, Artificial; Bradycardia; Treatment Outcome
PubMed: 38778360
DOI: 10.1186/s13019-024-02789-6 -
Stem Cell Research May 2024The heterozygous mutation c.155G > T in GNB2 clinically leads to sinus bradycardia and sinus node dysfunction. Here, patient-specific skin fibroblasts of the mutation...
Generation of a patient-specific hiPS cell line with heterozygous GNB2 mutation (UKMi003-A) causative for human sinus node dysfunction and a corresponding CRISPR/Cas9-corrected isogenic control (UKMi004-A).
The heterozygous mutation c.155G > T in GNB2 clinically leads to sinus bradycardia and sinus node dysfunction. Here, patient-specific skin fibroblasts of the mutation carrier were used for Sendai virus reprogramming into human induced-pluripotent stem cells (hiPSC). For generating the isogenic control cell line, a CRISPR/Cas9-mediated HDR-repair of the hiPSCs was carried out. Both generated cell lines (GNB2 SV5528, GNB2 K26) maintained a normal karyotype, cell morphology, pluripotency in immunofluoresence and RT-qPCR analysis. Both hiPSC-lines showed differentiation potential into all three germ layers. Differentiated cardiomyocytes of this isogenic set may pave the way for investigating pharmacological rescue strategies for sinus node dysfunction.
PubMed: 38776645
DOI: 10.1016/j.scr.2024.103446 -
Cureus Apr 2024We use vernakalant, an intravenous anti-arrhythmic, to cardiovert paroxysmal atrial fibrillation (AF) into sinus rhythm. It is a relatively atrium-selective,...
BACKGROUND
We use vernakalant, an intravenous anti-arrhythmic, to cardiovert paroxysmal atrial fibrillation (AF) into sinus rhythm. It is a relatively atrium-selective, early-activating potassium and frequency-dependent sodium channel blocker with a half-life of 2 to 3 hours. Due to concerns regarding its safety profile, it is not Food and Drug Administration (FDA)-approved.
OBJECTIVE
This study aims to assess the efficacy of intravenous vernakalant in cardioversion of paroxysmal AF and the safety of its use.
METHODS
Patients with paroxysmal AF who presented to the American University of Beirut Medical Center (AUBMC) between 2015 and 2020 and received vernakalant for cardioversion were included. Patients did not receive vernakalant if they had any of the following: QTc > 440 ms, heart rate < 50 bpm, acute coronary syndrome within the last 30 days, second- and third-degree atrioventricular (AV) block in the absence of a pacemaker, severe aortic stenosis (AS), use of intravenous antiarrhythmics (class I and class III) within four hours of vernakalant infusion, systolic blood pressure <100 mmHg, and heart failure (New York Heart Association (NYHA) III or NYHA IV class). The primary endpoint is conversion to sinus rhythm for at least one minute within 90 minutes of the start of the vernakalant infusion. The secondary endpoint included the presence of these side effects: bradycardia, QTc prolongation, AV block, ventricular arrhythmias, hypotension, taste alteration/dysgeusia, sneezing, nausea, vomiting, paresthesia, cardiogenic shock, or death.
RESULTS
The study included 23 patients with paroxysmal AF (15 men, mean age 54 ± 14 years). Fourteen patients (61%) cardioverted to sinus rhythm within 90 minutes of the start of the Vernakalant infusion. Seven patients (30%) reverted to sinus rhythm within 15 minutes after the first infusion. After treatment with vernakalant, four patients (17%) developed sinus bradycardia, and four patients (17%) developed first-degree AV block. No patient had a QTc greater than 460 ms. None of the patients experienced sinus pauses, high-grade AV block, ventricular arrhythmias, hypotension, dysgeusia, sneezing, nausea, vomiting, paresthesia, cardiogenic shock, or death.
CONCLUSION
Vernakalant had 61% efficacy in the rapid cardioversion of paroxysmal AF to sinus rhythm, was well tolerated, and had a low rate of adverse events in our study population.
PubMed: 38770450
DOI: 10.7759/cureus.58616