Blood leaks back into the chambers rather than flowing forward through the heart or into an artery. In the United States, backflow most often is due to prolapse. Prolapse is when the flaps of the valve flop or bulge back into an upper heart chamber during a heartbeat. Prolapse mainly affects the mitral valve.
NSTEMI is a shorthand medical term for non-ST segment elevation myocardial infarction. It is one type of myocardial infarction also called heart attack.
A nonblocking minimal spanning switch is a device that can connect N inputs to N outputs in any combination. The most familiar use of switches of this type is in a telephone exchange. The term non-blocking means that if it is not defective, it can always make the connection. The term minimal means that it has the fewest possible components, and therefore the minimal expense.