Mechanism of synchronization in isorhythmic A-V dissociation. 3. Computer model.
نویسندگان
چکیده
An analog computer model has been developed to study the mechanism of the atrioventricular synchronization in one type of isorhythmic A-V dissociation (pattern I). The computer model simulates the following biological feedback control system: (1) the ventricular pacemaker frequency is independent of arterial blood pressure (analogous to artificial ventricular pacing); (2) the frequency of the atrial pacemaker (usually the S-A node) varies inversely as the arterial blood pressure; (3) the phase difference (P-R interval) between these pacemakers is a determinant of the stroke volume; (4) for a given systemic arterial impedance and heart rate, the stroke volume determines the arterial blood pressure; and (5) after a finite delay, the arterial blood pressure exerts an inverse effect on the atrial frequency, to close the loop. Stroke volume increases progressively as the P-R interval increases from 0 to some optimum value. Stable synchronization can exist only when the mean P-R interval falls within this range of values, because only within this range does negative feedback prevail. Over the range of ventricular pacing frequencies within which synchronization can persist, the mean cardiac output and arterial blood pressure will vary inversely as the ventricular pacing frequency. Synchronization will persist only when there is an adequate closed-loop gain (consisting of the change in arterial blood pressure per unit change in P-R interval and change in heart rate per unit change in blood pressure).
منابع مشابه
Mechanism of Synchronization in Isorhythmic A-V Dissociation
An analog computer model has been developed to study the mechanism of the atrioventricular synchronization in one type of isorhythmic A-V dissociation (pattern I). The computer model simulates the following biological feedback control system: (1) the ventricular pacemaker frequency is independent of arterial blood pressure (analogous to artificial ventricular pacing); (2) the frequency of the a...
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عنوان ژورنال:
- Circulation research
دوره 28 1 شماره
صفحات -
تاریخ انتشار 1971