There are multiple definitions:

1. atrial refractory period(English)

   • Cardiology, Electrophysiology

2. absolute refractory period(English)

   • RRP
   • Electrophysiology, Physiology

3. alternative rites of passage(English)

4. acute radiation pneumonitis(English)

   • an inflammatory reaction that appears in the high-dose irradiated portion of the lungs after the completion of EBRT
   • EBRT
   • Pulmonology, Radiotherapy /radiation, Oncology
   • https://doi.org…-3993-8.00026-X

5. abnormal relaxation pattern(English)

   • often referred to as Grade I Diastolic Dysfunction or Impaired Relaxation, is a finding on an echocardiogram indicating that the heart's main pumping chamber (left ventricle) is not relaxing properly during the resting phase of the heartbeat. Common in patients with OSA
   • AHI, DD, OSA, RFP
   • Cardiology, Pathology, Sleep medicine
   • https://doi.org…2167(03)00003-9
   • https://doi.org…chest.121.2.422