Sorry this is a long posting. As a paramedic, I have perform CPR more times than I can remember, so I do have some experience with both successes and failures. It is a correct statement to say if the cause of cardiac arrest is cardiac in nature, CPR without early defibrillation will generally be unsuccessful, but to say it is never successful is not completely accurate. I have had one case where CPR alone, perform correctly and within the first minute was successful. In this case it was my mother. My mom has a history of Congestive Heart Failure (CHF), having a CHF crisis in the spring of 98' requiring her to stop smoking after 50+ years and to be under the care of a Cardiologist. One Sunday, the following winter (she generally comes over our house every Sunday for dinner), we had just sat down to eat, when she had what first appeared to be a seizure and then fell face forward into her dinner plate. I jump up, pulled her to the floor, while my middle daughter took the youngest to our bedroom, my oldest daughter started to push furniture out the way and my wife dialed 911. My mother was pulseless and apnic (not breathing), I initiated CPR immediately. Within minutes, spontaneous respirations and circulation returned. When the ambulance and medic unit arrived, she was beginning to talk, granted it was incomprehensible, but verbal communication never the less. The EKG showed no ectopy (adverse cardiac rhythm), so we administered no cardiac drugs. In the Emergency Department (ED), I discussed her condition with the ED Physician, who did not believe she arrested, as there was no evidence of an abnormal EKG and her cardiac enzymes were within normal ranges. They called in an on-call Cardiologist and Neurologist, both of whom felt she must have just fainted (not believing as a paramedic I know when someone is pulseless and apnic), believing CPR alone was not enough to resuscitated a person in cardiac arrest. They did hold her over night to perform additional tests, I talked to her regular Cardiologist in the morning and based upon the lack of additional evidence of any cardiac problems, they were going to release her in the afternoon. Around lunchtime I received a call from the hospital to come over immediately, as my mom had gone into cardiac arrest (pulseless Ventricular Tachycardia), had successfully defibrillated her and was in the process of sending to the Washington Hospital Center, for a cardiac catheterization. Fortunately her regular Cardiologist was at the hospital at the time and led the Code Team. When I arrived, he updated me on her condition and apologized for his colleges' disbelief that she had indeed arrested the night before and that rapid CPR alone was in fact successful. This particular physician is one of the finest gentlemen I know and has always treated me with professional courtesy, unlike some of his colleges. We discussed one on one, medically what must have occurred. In the old days, as part of CPR instruction, they used to teach giving a pre-cordial thump, which was thought to provide a mechanical form of defibrillation. It is no longer taught; as there is little solid evidence it is beneficial and delays the start of CPR. We theorized the initial chest compressions served as enough of a mechanical stimulus as to cause the heart to defibrillate. The rapid start of CPR prevented further ectopy and development of a cardiac enzyme pattern typical of cardiac arrest. My mom went on to have a 2X bypass, she is still alive and doing well for an 86 year old women. So CPR, without early defibrillation can on occasion, save lives, even if the cause of cardiac arrest is cardiac in origin. Pete