Background Cardiac implantable electric devices are commonly used to treat heart failure. Little is known about temporal and geographic variation in use of cardiac resynchronization therapy (CRT) devices in usual care settings.
A hammer drill, also known as a rotary hammer, roto-drill or hammering drill, (see also rotary drill) is a rotary drill with a hammering action. The hammering action provides a short, rapid hammer thrust to pulverize relatively brittle material and provide quicker drilling with less effort.
the usual features are a head most often made of steel and a handle also called a helve or haft most hammers are hand tools but there are also many powered versions called power hammers such as steam hammers and trip hammers for heavier uses such as forging