interval
(int'ĕr-văl 
)
[L. intervallum, a space between two palisades]
- A space or time between two objects or periods.
- A break in the course of disease or between paroxysms.
atrioventricular i.An interval between the beginning of atrial systole and ventricular systole, measured by an electrocardiogram, as the P-R interval.
birth i.The interval between a full-term pregnancy and the termination or completion of the next pregnancy. Parents manage the interval between births for personal, psychological, or economic reasons. Intervals of less than 17 months or more than 5 years increase the risk of certain maternal and child health problems, such as preeclampsia, eclampsia, low birth weight, preterm birth, and maternal mortality. SYN: interval birth spacing; interpregnancy interval.
ABBR: CI
The range of values within which it is expected (with a given probability) that the true value of a parameter will lie. SYN: credible interval.SEE: confidence level.
contraction i.The interval between uterine contractions. Relaxation of the uterine muscle replenishes the blood flow to the muscle and to the intervillous spaces of the placenta.
credible i.Confidence interval
dosing i.The time between administered doses. For example, a medication designed to be given “q6h” has a dosing interval of six hours. A vaccine may have a longer dosing interval, e.g., doses may be given weeks or months apart.
focal i.The distance between the anterior and posterior focal points of the eyes.
interpregnancy i.Birth interval.
lockout i.In patient-controlled analgesia (PCA), the interval in minutes a patient must wait between demand ed doses of pain relievers. During the lockout interval, no medications are delivered to the patient no matter how many times a dose is requested. Typical lockout intervals in PCA are between 5 and 15 min.
lucid i.A brief remission of symptoms, e.g., in psychosis, stroke, or traumatic brain injury.
postmortem i.The estimated number of hours, days, weeks, or months between the discovery of a cadaver and the time of death. Forensic scientists use a variety of techniques to make this determination, e.g., evidence of changes in body temperature, muscular rigidity, blood pooling, and bodily decomposition. Infestation by insects with known larval or pupal developmental stages provides valuable information when forensic scientists are examining bodies that have been dead for a long time.
Variant: PR interval
In the electrocardiogram, the interval between the onset of the P wave and the beginning of the QRS complex.Variant: QR interval
In the electrocardiogram, the interval between the onset of the QRS complex and the peak of the R wave.QRS i.In the electrocardiogram, the interval that denotes depolarization of the ventricles, between the beginning of the Q wave and the end of the S wave. Its normal duration is 120–200 msec. Shorter durations are found, e.g., in preexcitation. Longer durations are indicative of first-degree heart block.
QRST i.In an electrocardiogram, the ventricular complex.
SEE: electrocardiogram for illus.
Variant: QT interval
In an electrocardiogram, the interval of ventricular depolarization and repolarization, beginning with the QRS complex and ending with the T wave. SYN: QRST complex; Q-T segment.Variant: RR interval
In an electrocardiogram, the interval from the onset of one R wave to the onset of the next one, one complete cardiac cycle.serial i.The time it takes for a contagious disease to pass from one infected person to the next. Also known as the generation time.
Variant: ST interval
In an electrocardiogram, the interval that represents ventricular repolarization. An elevation of the S-T segment may be seen in myocardial infarction, variant angina, and ventricular aneurysms; depression of the S-T segment is seen in conditions such as coronary ischemia, left ventricular hypertrophy, and digitalis use.SEE: electrocardiogram for illus.; QRST complex.
surveillance i.In screening patients at risk for the development of a disease, the interval between the performance of successive tests.
TP i.In an electrocardiogram, the interval of electrical inactivity after the end of the T wave and before the beginning of the P wave.