Cardiac Pacemakers are used to regulate the hearts rhythm and prevent abnormal heart beats. Patients undergo a minimal surgery to get the pacemaker implanted in the body, whereas these devices do have their limitations such as battery life, power consumption and integrated circuit area which makes it difficult for elderly and children to undergo this surgery. This paper focuses on developing an optimised low pass filter ASIC design for implantable QRS complex detector for cardiac pacemaker circuits using filter optimisation techniques such as Pipelining and Folding of filters. The folded low pass filter design consumes an overall power of 0.7575 mW and comprises a total of 1361 standard cells. The number of adder block units in our work reduces area consumption by a factor of 48.37%.