Several embodiments of a battlefield defibrillation system (2) comprising external defibrillator (6) and at least one electrode (8) connected thereto are described. The system includes direct cardiac access (8), or indirect subcutaneous electrodes (30). The direct cardiac access electrodes (26) engage the heart muscle directly via the intercostal space. Indirect subcutaneous electrodes are positioned under patient's skin. Several design features are implemented to aid precise electrode positioning and facilitate system operation by an untrained personnel.