S1 is the first heart sound that doctors can hear using a stethoscope. The vibrations that occur when the mitral and tricuspid valves in the heart close produce the S1 sound. There are two common ...

A resting heart rate for an adult human is usually between 60 to 100 beats per minute, though that number varies greatly among other animals, as researchers have found that animal heart rates ...

Is your heart beating louder than usual, or is it just because you lie down to rest? These are common questions during pregnancy that can increase your worry. The heartbeat may echo in your ears and ...