My sister had a recient hospital stay and was put through a battery of tests. Was told she has braidiacardia, slow heart beat. Her heart rate for me (3 days now) has been in the 40's and low 50's. She had a spell that she was going unresponcive and was

A . A low heart rate is called "bradycardia" and is considered to be any heart rate less than 60 beats per minute. Bradycardia can either be a sign of a healthy, fit heart, or it can be a sign of a problem with the heart's electrical system. Marathon runners and other very fit, young athletes will often have very low heart rates - even in the 40-50 beats per minute range. If she does not fit into the "fit, young athlete" category, then there are other things to consider such as damage to the heart from coronary artery disease, heart attack, a metabolic problem such as hypothyroidism, or a medication which can cause a slowed heart rate as a side effect. Since she appears to be symptomatic with that unresponsiveness spell, you or she should discuss concerns with her doctor as soon as possible. They may want to check an ekg and a few blood tests to rule out problems with her heart. It may also be worthwhile to seek the advice of a cardiologist (heart specialist) if her doctor is not sure what to do. Good luck!