An external defibrillator apparatus (10, 74) operates to deliver electrical shocks to the heart muscles of a patient using a self-contained piezoelectric power source. The apparatus has a body (12) which includes a handle portion (26) in fixed operative connection with disposed paddle portions (14, 16). Each paddle portion includes a respective electrode (22, 24). Manual movement of a trigger (28, 78) is operative to cause circuitry (32, 82) which includes a piezoelectric crystal (34) to develop sufficient electrical potential between the electrodes to deliver the electrical shocks to the heart muscles through external contact with the patient's chest.