Leaky Heart Valve (What are the next steps)?

Greetings! I have a friend in India who is seeking medical help/consultation. She has been in and out of the hospital several times over the past several weeks. This is what she wrote on March 15:

MY DIAGNOSIS: 📈
I took soooo many tests: blood, urine, ecg, ekg, sonography, mri, 24 hour heart monitor. And the only issue they can attribute my episodes to is a leaky heart valve (a condition I was already diagnosed with when I was younger but as I got older it seemed to not hinder my daily activities). After moving to India 8 years ago, my health slowly declined. I think because of different unique stressors, the years of issues exacerbated my condition, and started getting really bad episodes on March 15. When discharged from the hospital, I noticed that even the smallest strain on my heart starts making me feel weak.

This is her Symptom Log Summary:
Known condition: Leaky heart valve Hospitalized recently, cause still undiagnosed
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Key Observations (Across Multiple Dates):
1. Cardiovascular-Related Symptoms: Rapid/increased heartbeat
Heart skipping beats
Slight chest pain
Heart feeling weak
Icy-hot sensation in chest
2. Neurological/Muscular Symptoms:
Uncomfortable and numbness (especially left arm)
Weakness in arms and legs
Pressure behind eyes
Twitching (upper lip)
Shivering episodes
Random bone/muscle pain (arms, legs, hands, feet, back, back of neck)
3. Gastrointestinal Symptoms:
Nausea
Indigestion
Difficulty eating, disinterest in food
Sensation of needing to go motion (but NOT diarrhea. Regular stools) Frequent urination
4. Throat and ENT Symptoms: Dry mouth and lips
Throat feels slightly closed Twitching upper lip
5. Systemic/Generalized Symptoms:
Feeling hot/sweaty episodes (in only hands and feet), sometimes slight temperature in head/neck area
Cold hands and feet
Puffy fingers (left side only) Shivering
Fatigue, general weakness
6. Appetite & Sensory Changes:
No hunger, or hunger without desire to eat Smell and taste changes
7. Mood & Other Sensations:
Anxiety/nervous feeling, especially pelvic area
Difficulty sleeping

New symptoms (Apr.21 while at the hospital after having episodes in the morning waiting to see the cardiologist): tightness around head, pressure behind ears (lasted for over an hour), lower back pain
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Notable Patterns:
Symptoms often worsen when lying down
Flare-ups are episodic
Heat seems to trigger or worsen symptoms
Many episodes include multisystem involvement (cardiac, neuro, digestive)
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Potential Areas for Medical Exploration:
Autonomic Dysfunction (e.g., POTS, dysautonomia)
Thyroid or Adrenal Dysfunction
Electrolyte/Nutrient Deficiencies (Magnesium, Potassium, B12, etc.) Autoimmune Disorders (Lupus, Sjögren's, etc.)
Mast Cell Activation Syndrome (MCAS)
Cardiac Monitoring (Holter or event monitor)
Gastrointestinal Function (GERD, IBS, gut microbiome)

**Any help, suggestions, recommendations would be great! Thank you so much for reading this post!