Sex and age impact prevalence and symptoms of vasovagal syncope: Implications for accurate diagnosis

Syncope is characterized by the transient loss of consciousness followed by spontaneous recovery. The mechanism which underlies this condition is reduced blood flow to the brain [1]. Vasovagal syncope, often termed reflex syncope, is the most common type of syncope [1]. Vasovagal Syncope is caused by the abnormal autonomic reflex to certain stimuli such as pain, micturition/defecation, fear, seeing blood, etc., which results in vasodilation and often times, bradycardia [1].

555 Torsade-de-pointes electrical storm late after treatment with hydroxychloroquine and azithromycin for COVID-19

A 78-year-old woman was admitted to our hospital due to multiple brief episodes of transient loss of consciousness. She was recently hospitalized elsewhere for SARS-CoV-2 infection and she had been discharged two days before. During the previous hospitalization she had been treated with hydroxychloroquine 400 mg twice daily on Day 1, followed by Hydroxychloroquine 400 mg daily together with azithromycin 500 mg daily for 7 days, leading to symptomatic resolution and two consecutive negative RT-PCR tests at discharge. Her medical history included dilated cardiomyopathy and in 2017 she underwent CRT-D implantation for primary prevention; over the past 3 years, she did not experience any ICD intervention. Her home therapy included amiodarone, bisoprolol, warfarin, and trazodone. Baseline ECG obtained 6 month before admission is shown in Figure 1, Panel A. On admission, her ECG showed sinus bradycardia with biventricular pacing and significant QT prolongation (i.e. 640 ms, Figure 1 B). On day 2 of hospitalization, she reported multiple brief episodes of transient loss of consciousness. An interrogation of her device revealed 27 torsade-de-pointes episodes in a 48-hour period, treated with 11 shocks. All episodes were preceded by a variable period of bigeminal rhythm due to one or two premature ventricular beats coupled to the prolonged QT segment of the preceding basic beat in a ‘short-long-short’ sequence (Figure 2). The patient experienced a torsade-de-pointes TdP during COVID-19 disease. She had multiple concomitant factors for QT prolongation (TISDALE SCORE 13): mainly, female sex, cardiac disease, inflammation, electrolyte imbalances and multiple QT-prolonging drugs. Amiodarone and bisoprolol were subsequently stopped and potassium and magnesium were supplemented, with rapid resolution of torsade-de-pointes. No more episodes of TdP were detected after two weeks of hospitalization. The remote monitoring assessment of her device did not show any further episodes during subsequent follow-up. To our best knowledge, this is the first ICD-documented report of a TdP electrical storm in a COVID-19 patient, treated with HCQ/AZT, who had multiple concomitant factors for QT prolongation. 555 Figure 1

Approach to Loss of Consciousness: Distinguishing Epileptic Seizures, Psychogenic Nonepileptic Seizures, and Syncope

Transient loss of consciousness (TLOC) is a common emergent neurological issue, which can be attributed to syncope, epileptic seizures, and psychogenic nonepileptic seizures. The purpose of this article is to outline an approach to diagnosing the most common etiologies of TLOC by focusing on the importance of the history and physical examination, as well as targeted diagnostic tests.

#3079 Investigating the feasibility of automating the differential diagnosis of transient loss of consciousness

BackgroundThere are three common causes of Transient Loss of Consciousness (TLOC), syncope, epileptic and psychogenic nonepileptic seizures (PNES). Many individuals who have experienced TLOC initially receive an incorrect diagnosis and inappropriate treatment. Whereas syncope can be distinguished from the other two causes relatively easily with a small number of yes/no questions, the differentiation of the other two causes of TLOC is more challenging. Previous qualitative research based on the methodology of Conversation Analysis has demonstrated that epileptic and nonepileptic seizures are described differently when patients talk to clinicians about their TLOC experiences. One particularly prominent difference is that epileptic seizure descriptions are characterised by more formulation effort than accounts of nonepileptic seizures.AimThis research investigates whether features likely to reflect the level of formulation effort can be automatically elicited from audio recordings and transcripts of speech and used to differentiate between epileptic and nonepileptic seizures.MethodVerbatim transcripts of conversations between patients and neurologists were manually produced from video and audio recordings of interactions with 45 patients (21 epilepsy and24 PNES). The subsection of each transcript containing the patients account of their first seizure was manually extracted for the analysis. Seven automatically detectable features were designed as markers of formulation effort. These features were used to train a Random Forest machine learning classifier.ResultsThere were significantly more hesitations and repetitions in descriptions of first epileptic than nonepileptic seizures. Using a nested leave-one-out cross validation approach, 71% of seizures were correctly classified by the Random Forest classifier.ConclusionsThis pilot study provides proof of principle that linguistic features that have been automatically extracted from audio recordings and transcripts could be used to distinguish between epileptic seizures and PNES and thereby contribute to the differential diagnosis of TLOC. Future research should explore whether additional observations can be incorporated into a diagnostic stratification tool. Moreover, future research should explore the performance of these features when they have been extracted from transcripts produced by automatic speech recognition and when they are combined with additional information provided by patients and witnesses about seizure manifestations and medical history.

Recommendations for tilt table testing and other provocative cardiovascular autonomic tests in conditions that may cause transient loss of consciousness

An expert committee was formed to reach consensus on the use of tilt table testing (TTT) in the diagnosis of disorders that may cause transient loss of consciousness (TLOC) and to outline when other provocative cardiovascular autonomic tests are needed. While TTT adds to history taking, it cannot be a substitute for it. An abnormal TTT result is most meaningful if the provoked event is recognised by patients or eyewitnesses as similar to spontaneous events. The minimum requirements to perform TTT are a tilt table, a continuous beat-to-beat blood pressure monitor, at least one ECG lead, protocols for the indications stated below and trained staff. This basic equipment lends itself to the performance of (1) additional provocation tests, such as the active standing test, carotid sinus massage and autonomic function tests; (2) additional measurements, such as video, EEG, transcranial Doppler, NIRS, end-tidal CO2 or neuro-endocrine tests; and (3) tailor-made provocation procedures in those with a specific and consistent trigger of TLOC. TTT and other provocative cardiovascular autonomic tests are indicated if the initial evaluation does not yield a definite or highly likely diagnosis, but raises a suspicion of (1) reflex syncope, (2) the three forms of orthostatic hypotension (OH), i.e. initial, classic and delayed OH, as well as delayed orthostatic blood pressure recovery, (3) postural orthostatic tachycardia syndrome or (4) psychogenic pseudosyncope. A therapeutic indication for TTT is to teach patients with reflex syncope and OH to recognise hypotensive symptoms and to perform physical counter manoeuvres.