Patient case (clinical description): A 23-year-old man comes to the emergency department following an episode of syncope.  He was working out when he felt dizzy and passed out without head injury.  He has had 3 other episodes of light-headedness over the last year, all happening during physical activity. He never had this experience while resting. He has no other medical conditions.  The patient does not use tobacco, alcohol, or illicit drugs.  His father died suddenly at age 35.  Vital signs are within normal limits.  On physical examination, the patient has a harsh systolic murmur.  The lungs are clear with no peripheral edema. Echocardiography shows asymmetric interventricular septal hypertrophy.

Patient's own account: I'm 23, and I got admitted to the ER because I fainted all of a sudden. I was in the gym, working out, when all of a sudden, I just got dizzy and passed out. Hopefully, I didn't hit my head. It's not my first time having that kind of dizziness at the gym, never when I'm chilling at home tho. I don't have any special medical conditions and I'm not even smoking, drinking or doing drugs! My dad died suddenly when he was 35, so I'm kind of scared. My vitals were normal while at the ER and they did a physical exam and they told me my heart sounds abnormal. My lungs are ok, but I had to do an echography of my heart, and they told me it is bigger than average.

Clinical trial: Diagnostic Yield of an Ambulatory Patch Monitor in Unexplained Emergency Department Syncope: A Pilot Study (PATCH-ED)

Eligibility criteria:
Inclusion Criteria:

          -  Patients aged 16 years or over presenting within 6 hours of an episode of syncope and
             whose syncope remains unexplained after ED assessment. Syncope will be defined as a
             transient loss of consciousness (TLOC) with inability to maintain postural tone and
             immediate complete spontaneous recovery without medical intervention (to preexisting
             mental status and neurologic function)

        Exclusion Criteria:

          -  Obvious underlying cause after ED assessment,

          -  Alcohol or illicit drugs as presumptive cause of TLOC [24],

          -  Epileptic seizure as presumptive cause of TLOC (seizure activity with a >15 min
             witness reported post-ictal phase) [24],

          -  Stroke ⁄ transient ischemic attack as presumptive cause of TLOC [24],

          -  Head trauma followed by TLOC [24],

          -  Hypoglycemia as presumptive cause of TLOC [24],

          -  No consent i.e. patient lacking capacity,

          -  Previous recruitment into the study,

          -  Patient in custody or prison.

        Obvious underlying causes will be defined as:

          -  Clinical history of vasovagal syncope i.e. pre-syncope symptoms and low-risk patient
             according to current ESC guidelines [14],

          -  Arrhythmia on ED ECG thought to have caused syncope,

          -  Arrhythmia on pre-hospital ECG causing syncope,

          -  Pulmonary embolism (PE) diagnosed on Computed Tomography Pulmonary Angiography (CTPA;
             or equivalent e.g. symptoms of PE plus positive leg ultrasound
             scan/ventilation-perfusion scan/echo),

          -  Postural hypotension (postural drop >20 mmHg in ED with symptoms during test and
             suggestive history),

          -  Myocardial Infarction [25],

          -  CT brain or clinical signs/symptoms in ED showing cerebrovascular accident or
             subarachnoid haemorrhage,

          -  Evidence of haemorrhage in ED thought to have caused syncope,

          -  Other obvious cause of syncope apparent in ED.
No condition on gender to be admitted to the trial.
No healthy subjects accepted to join the trial.
Subject must be at least 16 Years old.


Eligibility (NLI label): Contradiction