Sinus Bradycardia Publications (4161)
Sinus Bradycardia Publications
All rights reserved The aim of this study was to evaluate the role of ganglionated plexi (GP) in the innervation of the AVN by the right vagus nerve.
Direct epicardial high frequency stimulation (HFS) of the GP (20 patients) and the right vagus nerve (10 patients) was performed before and after fat pad exclusion or destruction in 20 patients undergoing thoracoscopic epicardial ablation for the treatment of persistent AF. Asystole longer than 3s or acute R-R prolongation over 25% was considered as a positive response to HFS. Prior to the ablation, positive responses to HFS were detected in three GPs in 7 patients (35%), two GP in 5 patients (25%), and one GP in 8 patients (40 %). After exclusion of the fat pads, all patients had a negative response to HFS. All the patients who exhibited a positive response to right vagus nerve stimulation (n = 10) demonstrated negative responses after the ablation.
The integrity of the GP is essential for the right vagus nerve to exert physiological effects of on AVN in humans.
We present an interesting case of a child with ictal sinus pause and asystole. A 27-month-old girl was hospitalized due to 5 episodes of convulsions during the past 2 days. Results of routine electroencephalography (EEG) were normal, but she experienced brief generalized tonic seizure for 3 days. During video-monitored EEG and echocardiography (ECG), she showed multiple myoclonic seizures simultaneously or independently, as well as frequent sinus pauses. After treatment with valproic acid, myoclonus and generalized tonic seizures were well controlled and only 2 sinus pauses were seen on 24-hour Holter ECG monitoring. Sinus dysfunction should be recognized on EEG, and it can sometimes be treated successfully with only antiepileptic medication.
Bradycardia has been reported following short term methylprednisolone and dexamethasone therapy in both adult and pediatric patients. There are only two case reports in the literature of bradycardia following short term intravenous dexamethasone use in adult patients. This is the first case report that describes bradycardia following the use of dexamethasone in the postoperative setting for management of laryngeal edema in an adult. Telemetry and twelve lead electrocardiograms revealed sinus bradycardia and correlated directly with administration of dexamethasone in our patient. Bradycardia resolved following discontinuation of dexamethasone. We advocate for hemodynamic monitoring in patients receiving more than one dose of intravenous steroid therapy in the perioperative period, especially those with known cardiac and hepatic comorbidities and those taking medications with negative chronotropic effects.
Ticagrelor has been associated with dyspnea and bradyarrhythmias, both attributed to increased adenosine exposure. Ticagrelor inhibits reuptake of intracellular adenosine. Adenosine antagonists aminophylline and theophylline have been utilized to reverse the effects of adenosine and may relieve adenosine-mediated adverse effects induced by ticagrelor therapy. Aminophylline may be considered for reversal of dyspnea and bradyarrhythmia associated with ticagrelor therapy through alterations in adenosine exposure.
Blood samples for PSA, NT-proBNP, and TnT were obtained at baseline and after 1, 3, and 6 months.
Five patients (29.4%) experienced G3 to 4 cardiac SAEs after a median of 13 weeks (range, 9-32), including pulmonary edema, heart failure, acute coronary syndrome, sinus bradycardia with syncope, and pulmonary edema. At baseline, 4 weeks, and 3 months, median NT-proBNP and TnT levels were higher in patients with subsequent cardiac SAEs (P= .03 and P= .04 for NT-proBNP and TnT at 3 months, respectively). After switching to dexametasone and introducing canrenone, no additional cardiac SAEs were noted. Overall response rate was 67%.
Our study suggests a higher than expected risk of cardiac SAEs during abiraterone treatment which may well be due to the small sample size and the unrestricted entry criteria. However, baseline and frequent NT-proBNP and TnT monitoring predicted a higher risk for cardiac SAE. Larger studies should confirm our findings.
Although available atrial electrograms in a dual chamber system improve interpretation of stored arrhythmia events, allow monitoring of atrial fibrillation and may potentially reduce the risk of inappropriate shocks by enhancing automated arrhythmia discrimination, the use of dual-chamber ICDs has a number of disadvantages. The addition of an atrial lead adds complexity to implantation and extraction procedures, increases procedural cost and is associated with a higher risk of periprocedural complications. The single lead pacing system with ability to sense atrial signals via floating atrial electrodes (VDD) clinically became available in early 1980's but did not gain much popularity due to inconsistent atrial sensing and concerns about the potential need for an atrial lead if sinus node fails. Most ICD patients do not have indications for pacing at implantation and subsequent risk of symptomatic bradycardia seems to be low. The concept of atrial sensing via floating electrodes has recently been revitalized in the Biotronik DX ICD system (Biotronik, SE & Co., Berlin, Germany) aiming to provide all of the potential advantages of available atrial electrograms without the risks and incremental cost of an additional atrial lead. Compared to a traditional VDD pacing system, the DX ICD system uses an optimized (15 mm) atrial dipole spacing and improved atrial signal processing to offer more reliable atrial sensing. The initial experience with the DX system indicates that the clinically useful atrial signal amplitude in sinus rhythm remains stable over time. Future studies are needed to determine reliability of atrial sensing during tachyarrhythmias, particularly atrial fibrillation as well as clinical utility and cost-effectiveness of this technology in different populations of patients.
However, evidence from randomised trials about the efficacy and safety of ablation in non-paroxysmal atrial fibrillation is limited.
To determine the efficacy and safety of ablation (catheter and surgical) in people with non-paroxysmal (persistent or long-standing persistent) atrial fibrillation compared to antiarrhythmic drugs.
We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE Ovid, Embase Ovid, conference abstracts, clinical trial registries, and Health Technology Assessment Database. We searched these databases from their inception to 1 April 2016. We used no language restrictions.
We included randomised trials evaluating the effect of radiofrequency catheter ablation (RFCA) or surgical ablation compared with antiarrhythmic drugs in adults with non-paroxysmal atrial fibrillation, regardless of any concomitant underlying heart disease, with at least 12 months of follow-up.
Two review authors independently selected studies and extracted data. We evaluated risk of bias using the Cochrane 'Risk of bias' tool. We calculated risk ratios (RRs) for dichotomous data with 95% confidence intervals (CIs) a using fixed-effect model when heterogeneity was low (I² <= 40%) and a random-effects model when heterogeneity was moderate or substantial (I² > 40%). Using the GRADE approach, we evaluated the quality of the evidence and used the GRADE profiler (GRADEpro) to import data from Review Manager 5 to create 'Summary of findings' tables.
We included three randomised trials with 261 participants (mean age: 60 years) comparing RFCA (159 participants) to antiarrhythmic drugs (102) for non-paroxysmal atrial fibrillation. We generally assessed the included studies as having low or unclear risk of bias across multiple domains, with reported outcomes generally lacking precision due to low event rates. Evidence showed that RFCA was superior to antiarrhythmic drugs in achieving freedom from atrial arrhythmias (RR 1.84, 95% CI 1.17 to 2.88; 3 studies, 261 participants; low-quality evidence), reducing the need for cardioversion (RR 0.62, 95% CI 0.47 to 0.82; 3 studies, 261 participants; moderate-quality evidence), and reducing cardiac-related hospitalisation (RR 0.27, 95% CI 0.10 to 0.72; 2 studies, 216 participants; low-quality evidence) at 12 months follow-up. There was substantial uncertainty surrounding the effect of RFCA regarding significant bradycardia (or need for a pacemaker) (RR 0.20, 95% CI 0.02 to 1.63; 3 studies, 261 participants; low-quality evidence), periprocedural complications, and other safety outcomes (RR 0.94, 95% CI 0.16 to 5.68; 3 studies, 261 participants; very low-quality evidence).
In people with non-paroxysmal atrial fibrillation, evidence suggests a superiority of RFCA to antiarrhythmic drugs in achieving freedom from atrial arrhythmias, reducing the need for cardioversion, and reducing cardiac-related hospitalisations. There was uncertainty surrounding the effect of RFCA with significant bradycardia (or need for a pacemaker), periprocedural complications, and other safety outcomes. Evidence should be interpreted with caution, as event rates were low and quality of evidence ranged from moderate to very low.
We present a case of a 53-year-old woman who initially presented with episodes of expressive aphasia and was treated with antiepileptic drugs (AEDs). While on therapy she experienced episodes of syncope. During her hospitalization for tapering of AEDs and 24-hour EEG monitoring, the patient developed a seizure followed by sinus bradycardia and an 18-second sinus pause, resulting in loss of consciousness and slowing of cerebral activity. Ten seconds after the return of cardiac activity, the EEG showed return of cerebral activity. A dual chamber pacemaker was implanted.
Although a pacemaker is not always effective because of a concomitant vasodepressive response in such cases, the complete stabilization after pacemaker implantation in this case supports the necessity and usefulness of pacemaker implantation in patients with reflex-induced highly symptomatic bradycardia.
However, the mechanistic details connecting AN to cardiac abnormalities remain unknown. Here we present an endomyocardial biopsy of the left ventricle in a case of AN with a reversible left ventricular systolic dysfunction.