Acquiring Analog signal and transmitting it through Bluetooth module HC-05

Hello all,
I have designed a DIY project to acquire ECG signal now i have to transmit it through Bluetooth module HC-05. I have connected the analog output of my DIY ECG model to the A0 of analog input of my arduino R3 development board. I have connected the bluetooth module HC-05 correctly now i am cofused how the analog signal be converted to digital for the transmission through HC-05 as I am not much familiar with the arduino coding. Please help me out here.