GB1421485A - Heart pacers - Google Patents

Abstract

1421485 Heart pacemakers AMERICAN OPTICAL CORP 16 April 1973 [14 April 1972] 18300/73 Heading A5R An atrial and ventricular heart pacer has ventricular stimulating pulse generating means 65, T9, first means 35a for varying the rate of generation of said pulses, means T6 for synchronising the ventricular pulse generator to the beating action of the patient's heart, timing means 58, T11, T12 for operating in synchronism with the beating of the patient's heart and producing an atrial timing interval, second means 62a for adjusting the width of the atrial timing interval, means T14 responsive to the expiration of the atrial timing interval for generating an atrial stimulating pulse and means for effecting the automatic adjustment of the second means 62a when the first means 35a is adjusted. The pacemaker is substantially identical to that disclosed in Specification 1416563, except that a timing circuit of the ventricular pulse generator includes a variable resistor 35a gauged to a variable resistor 62a in a timing circuit of the atrial pulse generator which includes a second variable resistor 62b adjustable independently of resistor 62a. Resistors 35a, 62a are matched so that their simultaneous adjustment alters the rate of ventricular pulse generation without altering the A-V delay between an atrial stimulating pulse and the next ventricular stimulating pulse which should occur, whereas the adjustment of resistor 62b adjusts said AV delay without altering the ventricular pulse generation rate. Specifications 1414861 1374720 1397290 1266907 1307912 and 1335679 are referred to.