Intracardiac medication is rarely, if ever used. And that was only in the hospital back in the old ('70s) days. The movie Pulp Fiction was just that, fiction. If a patient that was in cardiac arrest (BTW, heart attack usually refers to a myocardial infarction, not cardiac arrest) and in ventricular fibrillation (or pulseless v-tach) was defibbed into asystole (flatline), the medics would start with the asystole protocol which is usually (following intubation and IV access) 1 mg IV of 1:10,000 epinephrine (1 mg in 10cc), followed by 30 secs/1 minute of CPR to circulate it. Then follow that with 1 mg IV of atropine and CPR. After 3 to 5 mins, repeat the medications. Treatable causes (like hyperkalemia, acidosis, etc.) of asystole are considered too, but in most cases, asystole is usually irreversible. We are rarely able to resuscitate asystolic patients.