A Holter exam records the heart for 24 hours — but the symptoms live in the patient’s memory. The classic protocol is a paper diary: note the time, note the feeling, hope the watch was right. Correlating that with the recording afterwards is guesswork.

The person using this app may be mid-palpitation. So the interface is one action: tap when a symptom hits. The time is recorded automatically — nothing to write, nothing to remember — and the doctor receives the exam’s full timeline, start to finish. Health data handled per LGPD, access restricted to the doctor.

A symptom log is only useful if it reaches someone. The doctor opens a panel: who is recording right now, how many events each patient has logged, when the last one came in — and, one click deeper, the full timeline of the exam.

Fitting a Holter takes minutes and the patient is already in the room, so registering one asks for a single required field. The six-digit code is generated on the spot and goes out over WhatsApp or Telegram — the patient is recording before they leave the clinic.

Vanilla JavaScript, Supabase, Vercel — a full-stack PWA with no framework overhead, installable on the patient’s phone. Designed, built and shipped solo: the same hands did the UX, the interface and the backend.