Clinical Characteristics And Prognosis of Vasovagal Syncope With Sinus Arrest In Children

The aim of this study was to analyze the clinical characteristics and prognosis of vasovagal syncope(VVS) with sinus arrest in children. From July 2017 to October 2020, cases of VVS with sinus arrest were recruited from patients diagnosed as VVS in our department. The clinical data, the results of the head-up tilt testing (HUTT), and follow-up information were analyzed. 223 patients were diagnosed as VVS during the time, and 10 cases of VVS with sinus arrest were recruited, who had a median age of 9.5 years（interquartile range: 6.8 to 10.4 years), a gender ratio of 1:1, and median sinus arrest time of 7.7s(range: 3.39 to 19s). These patients were given oral rehydration salts and orthostatic training, as well as 2 children treated with metoprolol and 5 children with sertraline hydrochloride. No child was implanted with pacemakers. During a median of 26 months of follow-up (interquartile range: 21 to 33 months), only one of the children had once syncope episode, three children had 1~4 times of prodromal symptoms. Conclusion The present research most crucial finding was that VVS patients with sinus arrest in children were younger than ordinary pediatric VVS patients. Oral rehydration salts(ORS) and autonomic nerve function exercise may improve clinical symptoms in children with VVS accompanied by sinus arrest. Pacemakers for VVS with sinus arrest in children should be cautious.

Abstract 10125: Continuous Heart Rate Dynamics Preceding In-Hospital Cardiac Arrest of Respiratory Etiology

Introduction: Respiratory failure is a common cause of pulseless electrical activity (PEA) arrest in hospitalized patients, but how pathophysiologic changes in these conditions affect heart rate (HR) pre-arrest is not well described. We describe HR dynamics prior to in-hospital cardiac arrest (IHCA) among PEA/asystole arrest patients with respiratory etiology. Methods: In this retrospective descriptive study, we evaluated 67 patients with ≥3 hours of continuous ECG data recorded immediately preceding PEA/asystole IHCA in a single institution from 2010-2014. We identified respiratory arrest cases (eg. pneumonia, aspiration, pulmonary embolism, acute respiratory distress syndrome) by chart review and evaluated ECG patterns up to 24 hours prior to arrest to identify patterns of HR increase, HR decrease, sinus arrest, and escape rhythms. Results: We identified 31/67 patients with respiratory etiology (age 59±17 years, 52% male, 83% return of spontaneous circulation, 41% survived to discharge); of these 23/31(74%) fit an a priori model of HR response (Figure). Twelve cases demonstrated clear onset of HR increase at a median of 44 (IQR 28-507) minutes prior to arrest, while the remaining 11 cases started the monitoring period in sinus tachycardia. The mean peak HR was 120±20 bpm. An abrupt onset of HR decrease occurred at a median of 3.4 (IQR 2.3-5.9) minutes prior to arrest. Sinus arrest occurred during the HR decrease phase in 18/23 cases; the first escape rhythm was atrial in 11 (61%), junctional in 2 (11%) and ventricular in 3 (17%) cases. Conclusion: The majority of IHCA due to respiratory etiology (74%) follow a typical model of HR increase due to physiologic compensation to hypoxia, followed by rapid HR decrease leading to PEA arrest, likely from the vagal effect of hypoxia and sinus node suppression from acidosis. Understanding HR trends can aid clinical management as well as development of artificial intelligence models for prediction of IHCA.

Ventricular fibrillation and prolonged asystole in asymptomatic mitral annular disjunction

A previously asymptomatic 20-year-old woman with mitral valve prolapse presented with ventricular fibrillation. After subcutaneous cardiac defibrillator implantation, she experienced sinus arrest without ventricular escape.

When the brain slows the heart—herpes encephalitis and sinus arrest: a case report

Background Herpes simplex virus (HSV) encephalitis is a known cause of cognitive deterioration, neurological disturbances, and seizures though are rarely associated with sinus node dysfunction. Case summary We present a 54-year-old man admitted to the hospital with a 10-day history of fever, confusion, and fatigue, 1 week following a transient loss of consciousness. An initial workup suggested HSV encephalitis and the patient was started on intravenous Acyclovir. Due to his episode of syncope, a 24 h Holter electrocardiogram monitoring was performed. The Holter documented multiple episodes of sinus arrest, with a second episode of syncope noticed by the hospital staff concurrent with the last documented sinus arrest. Following antiviral treatment and resolution of the encephalitis we noticed complete resolution of sinus node dysfunction. We subsequently avoided permanent pacemaker implantation. Discussion Our case of proven HSV encephalitis complicated by sinus node arrest and syncope with complete resolution following antiviral treatment suggests no indication for permanent pacemaker implantation. This approach is consistent with data from previously reported cases.