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: Midodrine and Fludrocortisone for Vasovagal Syncope

Eligibility criteria:
Inclusion Criteria:

          -  Vasovagal syncope as the cause of transient loss of consciousness (Clinical diagnosis
             AND Calgary Syncope Symptom Score ≥ -2; Head-up tilt test is not mandatory for
             diagnosis)

          -  ≥2 episodes of syncope during the last year

          -  Medication-naïve or have at least a 2-week washout period prior to randomization

          -  The capability of giving informed consent

          -  Signed written informed consent

        Exclusion Criteria:

          -  Other causes of transient loss of consciousness including orthostatic hypotension,
             postural tachycardia, carotid sinus hypersensitivity, or seizure

          -  Cardiac rhythm disorders including ventricular tachycardia, long QT syndrome, Brugada
             syndrome, arrhythmogenic right ventricular cardiomyopathy, complete heart block, and
             any conduction abnormality on electrocardiogram

          -  Severe valvular heart disease

          -  Hypertrophic cardiomyopathy

          -  Cardiac systolic dysfunction (ejection fraction≤40%)

          -  Obstructive coronary artery disease

          -  Hypertension

          -  Diabetes mellitus

          -  Cirrhosis

          -  Renal failure stage≥3

          -  Known intolerance or hypersensitivity to midodrine or fludrocortisone

          -  Urinary retention

          -  Pheochromocytoma

          -  Thyrotoxicosis

          -  Glaucoma

          -  Previous use of midodrine or fludrocortisone for treatment of VVS or another condition

          -  Pregnancy or breastfeeding
No condition on gender to be admitted to the trial.
No healthy subjects accepted to join the trial.
Subject must be at least 18 Years old.
Subject must be at most 65 Years

Eligibility (NLI label): Contradiction