No. SCA is an electrical problem in the heart. When people have SCA, they are not awake, their hearts are not beating, and they are unable to communicate. Symptoms of SCA include sudden loss of responsiveness and absence of normal breathing. In contrast, a heart attack is a circulatory problem in the heart. When people have heart attacks, they are awake, their hearts are beating, and they are able to communicate. Symptoms of heart attack can include chest discomfort; pain or discomfort in one or both arms, the back, neck, jaw or stomach; shortness of breath; sweating; nausea; and lightheadedness. Heart attacks can lead to SCA, but there also are many other causes.