A time or space between two periods or objects; a break in continuity. [L. inter-vallum, space between breastworks in a camp, an interval, fr. vallum, a rampart, wall]
A-H 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 A-V node (normally 50-120 msec).
A-N i. the time between onset of the atrial deflection and the nodal potential (normally 40-100 msec).
atriocarotid i. , a-c i. obsolete term for the time between the beginning of the atrial and that of the carotid waves in a tracing of the jugular pulse.
atrioventricular i. auriculoventricular i
auriculoventricular i. the time between depolarization of the atria and of the ventricle.atrioventricular i;
A-V 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.
BH i. the duration of the His bundle deflections (normally 15-20 msec).
cardioarterial i. , c-a i. the time between the apex beat of the heart and the radial pulse beat.
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., usually expressed in hundredths of a second, 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.
focal i. the distance between the anterior and posterior focal points of the eye.
H-V i. the time from the initial deflection of the His bundle (H) potential and the onset of ventricular activity (normally 35-45 msec).
interectopic i. the distance between consecutive ectopic complexes in the electrocardiogram.
isovolumic i. time during which both an A-V and a semilunar valve are closed.
lucid i. in psychoses or delirium, a rational period appearing in the course of the mental disorder.
P-A 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 intra-atrial conduction time.
P-J i. the time elapsing from the beginning of the P wave to the end of the QRS complex (J for junction between QRS and S-T segment) in the electrocardiogram.
P-P i. the distance between consecutive P waves in the electrocardiogram.
P-Q i. P-R i
P-R 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.P-Q i;
Q-R i. the time elapsing from the onset of the QRS complex to the peak of the R wave; measures the time of onset of the intrinsicoid deflection if determined in an appropriate unipolar lead tracing.
Q-RB i. the time between the onset of the Q wave of the QRS complex and the right bundle-branch potential (normally 15-20 msec).
QRS i. the duration of the QRS complex in the electrocardiogram.
Q-S2 i. electromechanical systole
Q-T i. time from electrocardiogram Q wave to the end of the T wave corresponding to electrical systole.
R-R i. the time elapsing between two consecutive R waves in the electrocardiogram.
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.ejection period;
Sturm's i. the distance between the anterior and posterior focal lines in a spherocylindrical lens combination.
systolic time i.'s See electromechanical systole, left ventricular ejection time, preejection period.
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