Circuits are grounded for the. purpose of limiting the voltage upon the circuit which might. otherwise occur through exposure to lightning or other voltages. higher than that for which the circuit is designed; or to limit. the maximum potential to ground due to normal voltage. (b) Exposed Enclosures.
More important, there are differences in the underlying cause of these two types of heart attack and, therefore, in the initial treatment. A STEMI heart attack is caused when a blood clot suddenly forms, completely blocking an artery in the heart. This can result in damage that covers a large area of the heart and extends deep into the heart muscle.
A posterior STEMI occurs when the posterior area of the left ventricle, usually supplied by posterior descending artery (a branch of right coronary artery in 80% cases) is occluded by a thrombus. Isolated posterior STEMI is rare. The majority of cases it occurs with inferior STEMI or lateral STEMI.