- A time or space between two periods or objects; a break in continuity. [L. inter-vallum, space between breastworks in a camp, an i., fr. vallum, a rampart, wall]- AH i. the time from the initial rapid deflection of the atrial wave to the initial rapid deflection of the His bundle (H) potential; it approximates the conduction time through the AV node (normally 50–120 msec).- AN i. the time between onset of the atrial deflection and the nodal potential (normally 40–100 msec).- auriculoventricular i. the time between depolarization of the atria and of the ventricle. SYN: atrioventricular i..- AV i. the time from the beginning of atrial systole to the beginning of ventricular systole as measured from pressure pulses or cardiac volume curves in animals, or from the electrocardiogram in humans.- calibration i. the period of time or series of measurements during which calibration can be expected to remain stable within specified and documented limits.- confidence i. a range of values for a variable of interest, constructed so that this range has a specified probability of including the true value of the variable.- coupling i. the i., expressed in milliseconds, between a normal sinus beat and the ensuing premature beat.- escape i. the time between the last beat of the patient's basic rhythm (ectopic or sinus beat) and a beat from a spontaneous escape focus or the initial electronic pacemaker impulse (a preset i. in the circuitry); it may be either a shorter or a longer time period than the pulse i..- HV i. the time from the initial deflection of the His bundle (H) potential and the onset of ventricular activity (normally 35–45 msec).- lucid i. in psychoses or delirium, a rational period appearing in the course of the mental disorder.- PA i. the time from onset of the P wave to the initial rapid deflection of the A wave in the His bundle electrogram (normally 25–45 msec); it represents the intraatrial conduction time.- PJ i. the time elapsing from the beginning of the P wave to the end of the QRS complex (J for junction between QRS and T wave) in the electrocardiogram.- PQ i. SYN: PR i..- PR i. in the electrocardiogram, the time elapsing between the beginning of the P wave and the beginning of the next QRS complex; it corresponds to the a-c i. of the venous pulse and is normally 0.12–0.20 sec. SYN: PQ i..- QR i. the time elapsing from the onset of the QRS complex to the peak of the R or the final R wave; measures the time of onset of the intrinsicoid deflection if determined in an appropriate unipolar lead tracing.- QRB i. the time between the onset of the Q wave of the QRS complex and the right bundle-branch potential (normally 15–20 msec).- QS2 i. SYN: electromechanical systole.- QT i. time from electrocardiogram Q wave to the end of the T wave corresponding to electrical systole.- serial i. the period of time between analogous phases of an infectious illness in successive cases of a chain of infection that is spread from person to person. SEE ALSO: mass action principle, infection transmission parameter.- sphygmic i. the period in the cardiac cycle when the semilunar valves are open and blood is being ejected from the ventricles into the arterial system. SYN: ejection period.- Sturm i. the distance between the anterior and posterior focal lines in a spherocylindrical lens combination.- systolic time intervals See electromechanical systole, left ventricular ejection time, preejection period.
* * *in·ter·val 'int-ər-vəl n a space of time between events or states <\intervals between pregnancies>
* * *in·ter·val (inґtər-vəl) [inter- + L. vallum rampart] the space between two objects or parts; the lapse of time between two recurrences or paroxysms.
Medical dictionary. 2011.