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.
When the heart is actively beating, âsystoleâ occurs. That's when blood flows from the heart and into the arteries. When blood is being actively pushed into the arteries during systole, the pressure in the arteries increases. The peak blood pressure during cardiac contraction is called the systolic blood pressure. A condition called isolated systolic hypertension occurs when the systolic pressure rises to 140 mm Hg or above and the diastolic pressure remains below 90 mm Hg. Isolated systolic hypertension usually affects older people and is the result of a very clear and known disease process somewhere else in the body.