Certified Cardiographic Technician (CCT) Practice exam

Myocardial necrosis, which occurs when there is a significant death of the heart muscle cells due to prolonged ischemia, often presents with very particular EKG changes. One of the hallmark features of myocardial necrosis is the development of significant Q waves. These Q waves are indicative of a previous myocardial infarction (heart attack), specifically an area of the heart muscle that has undergone necrosis. The reason for the appearance of significant Q waves is that during and after the necrosis, the electrical conduction through the heart is altered, leading to a greater depth and width of the Q waves on the EKG. These waves reflect the loss of viable myocardial tissue that would normally contribute to the electrical impulses generated in the heart. In contrast to other potential EKG changes: inverted T waves suggest ischemia rather than necrosis; ST segment elevation is typically seen in acute injuries rather than established necrosis; and normal sinus rhythm indicates a heart that is functioning normally without any ischemic or necrotic changes. Therefore, the presence of significant Q waves provides clear evidence of underlying myocardial damage from necrosis.