Is a fast heart rate sign of attack?

Not necessarily. A fast heart rate can have many causes, such as exercise, stress, anxiety, caffeine consumption, or thyroid issues, and is not necessarily a sign of an impending heart attack. However, if you experience chest pain, shortness of breath, or other typical heart attack symptoms along with a fast heart rate, it's important to seek immediate medical attention. Consult a healthcare professional if you have any concerns about your heart rate or chest pain.