There are multiple definitions:

1. integral shape averaging(English)

2. intrinsic sympathomimetic activity(English)

   • see also beta-adrenoceptor blocker
   • CHF, MSA
   • Nervous activity - (para)sympathetic, Pharmacology / pharmaceutics

3. incomplete strut apposition(English)

   • PCI
   • Coronary circulation

4. individual sport athlete(English)

   • refers to effects of plyometric jump training on their physical fitness
   • PJT
   • Sports medicine
   • https://doi.org…717/peerj.11004

5. immunosuppressive agent(English)

   • AA, AAD, FDA, HF, IFN, JAKi, MHC, SALT
   • Immunology, Dermatology, Therapeutic approaches
   • https://doi.org…aad.2023.05.049

6. initial R-wave surface area(English)

   • a novel electrocardiogram-based metric, calculated by multiplying the R-wave duration (ms) by its amplitude (mV) in leads V1 or V2, used to differentiate the origin of ventricular arrhythmias (like PVC or VT) as originating from the LVOT or RVOT. A larger ISA value (e.g., ≥15) typically points to an LVOT origin
   • OTVA, DTA, ECG, LVOT, NMA, PVC, RVOT, RBBB, RFCA, TZI, VA, VT
   • Cardiology, Pathology, Electrophysiology
   • https://doi.org…jnl-2025-326550