There are multiple definitions:

1. homologous mitotic recombination(English)

   • Genetics

2. heart-to-mediastinum ratio(English)

   • the mean number of counts for each heart ROI is divided by the mean number of counts in a 7 by 7 pixels mediastinum ROI; major predictor of sudden death and cardiac events in HF patients; a value < 1.6 is associated with an increased risk; aka H/M
   • CZT, HF, ROI, MIBG, H/M
   • Cardiology, Medical imaging, Risk factor, Ratio-based metric
   • https://doi.org…umed.117.194373
   • https://doi.org…2350-016-0724-8

3. health maintenance record(English)

4. hospital medical record(English)

5. hazardous materials regulations(English)

   • Safety and health

6. histiocytic medullary reticuloendotheliosis(English)

7. hyperemic microvascular resistance(English)

   • also denoted as hMR
   • BMR, HSR, AEP, CAD, CFR, CMD, MVR, MVT, WIA
   • Hemodynamics, Coronary circulation
   • https://doi.org…ehjopen/oeaf050