| qqh | every four hours [Lat. quaque quarta hora] |
|---|---|
| QR | quality review; quantity is correct [Lat. quantum rectum]; quieting response; quinaldine red |
| qr | quadriradial; quantity is correct [Lat. quantum rectum]; quarter |
| QRB | Quality Review Bulletin |
| QRM | quality and resource management |
| QRS | in electrocardiography, the complex consisting of Q, R, and S waves, corresponding to depolarization of ventricles [complex]; in electrocardiography, the loop traced by QRS vectors, representing ventricular depolarization [interval] |
| QRS-ST | the junction between the QRS complex and the ST segment in the electrocardiogram [junction] |
| QRS-T | the angle between the QRS and T vectors in vectorcardiography [angle] |
| QRZ | wheal reaction time [Ger. Qaddel Reaktion Zeit] |
| QS | question screening; quiet sleep |