Congestive heart failure, or simply heart failure, is progressive and should not be confused with a heart attack, which involves sudden tissue death of the heart muscle. Although heart failure may occur suddenly in some cases, gradual loss of function is more common.
I believe SI it stands for: Sacroiliac Joint Injections Sacroiliac (SI) joint injections are commonly used to determine what is causing back pain. SI joint injections are primarily diagnostic injections, meaning that they help your doctor determine the cause of your back pain but may not provide you with any long-term relief from the pain.
The sievert (symbol: Sv) is a derived unit of ionizing radiation dose in the International System of Units (SI).he sievert is used for a number of dose quantities which are described in this article and are part of the international radiological protection system devised and defined by the ICRP and ICRU.