A method and apparatus for treating a cardiac condition in a human or animal patient comprises contacting an area of skin spanning the chest area of the patient with at least two patches or electrode paddles that apply low voltages and currents in a rotational manner to pre- stimulate that area, followed by applying a high voltage shock in rapid succession through the patient's heart through at least two electrode pad patches or paddles, wherein an amplifier-based external defibrillation cardioversion system is used. Also, an external pacing system is employed using ascending ramp or any arbitrary ascending or level waveform for transcutaneous pacing which employ a constant current delivery mode. Treatable conditions include atrial fibrillation (AF), atrial tachycardia (AT), ventricular fibrillation (VF), and ventricular tachycardia (VT).