Low-pressure area mesocyclones, but more often develop from environments of high instability and low vertical wind shear. In deserts, lack of ground and plant moisture that would normally provide evaporative cooling can lead to intense, rapid solar heating of the lower layers of air. The hot air is less dense than surrounding cooler air. This, combined with the rising of the hot air, results in a low-pressure area called a thermal low. Monsoon circulations are caused by thermal lows which form over large areas of land and their strength is driven by how land heats more quickly than the surrounding nearby ocean.
Pressure overload Pressure overload Pressure overload refers to the pathological state of cardiac muscle in which it has to contract while experiencing an excessive afterload. Pressure overload may affect any of the four chambers of the heart, though the term is most commonly applied to one of the two ventricles. Chronic pressure overload leads to concentric hypertrophy of the cardiac muscle, which can in turn lead to heart failure, myocardial ischaemia or, in extreme cases, outflow obstruction. Any obstruction to the outflow of one of the chambers of the heart can lead to pressure overload. A forceful apex beat indicates left ventricular