This chest tightness can change from day to day, and/or from moment to moment. All of the above combinations and variations are common. This type of chest tightness is commonly misconstrued as heart problems or the signs of a heart attack.
Cardiac arrest, also known as cardiopulmonary arrest or circulatory arrest, is a sudden stop in effective blood circulation due to the failure of the heart to contract effectively or at all. Medical personnel may refer to an unexpected cardiac arrest as a sudden cardiac arrest (SCA).
Unsynchronized cardioversion (defibrillation) is a HIGH ENERGY shock which is delivered as soon as the shock button is pushed on a defibrillator. This means that the shock may fall randomly anywhere within the cardiac cycle (QRS complex). Unsynchronized cardioversion (defibrillation) is used when there is no coordinated intrinsic electrical activity in the heart (pulseless VT/VF) or the defibrillator fails to synchronize in an unstable patient.