AH interval

AH in·ter·val

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).

AH Interval

A period measured by electrophysiological studies of the heart, which is equal to the time between the onset of the first rapid atrial deflection and the His bundle deflection. Because the lower right atrium and the His bundle delineate the anatomic boundaries of the AV node, the AHI—usually 55–130 msec—is essentially equivalent to the AV nodal conduction time. The AHI is decreased by atropine and isopreterenol, and increased by adenosine, digitalis, some class I antiarrhythmics (e.g., moricizine), propranolol, rapid or premature atrial pacing, vagal manoeuvers, and verapamil.

AH interval

Cardiology A period measured by electrophysiologic studies of the heart, equal to the time between the onset of the first rapid atrial deflection and the His bundle deflection; as the lower right atrium and the His bundle delineate the anatomic boundaries of the AV node, the AHI–usually 55-130 msec is essentially equivalent to the AV nodal conduction time; the AHI is ↓ by atropine and isopreterenol, and ↑ by adenosine, digitalis, some class I antiarrhythmics–eg, moricizine, propranolol, rapid or premature atrial pacing, vagal maneuvers, and verapamil. Cf HV interval.

AH in·ter·val

(in'tĕr-văl) 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).