Annual deaths from tornadoes, earthquakes and floods together total fewer than 200. The most deadly heat wave in recent years occurred in Chicago over a week in July 1995, when temperatures hovered around 100 degrees.
Cardiac Cycle: 1st Systole Phase. During the systole phase, the right ventricle receives impulses from the Purkinje fibers and contracts. The atrioventricular valves close and the semilunar valves open. The de-oxygenated blood is pumped into the pulmonary artery.
Systolic heart murmur. Systolic heart murmurs are heart murmurs heard during systole. They can be classified by when the murmur begins and ends, between S1 and S2. Many involve stenosis of the semilunar valves or regurgitation of the atrioventricular valves. 1 Types.