Asystole is defined as the absence of electrical activity and the cessation of contractions. Asystole is the end stage of any cardiac arrest because all fatal rhythms degenerate into asystole. A cardiac arrest may also begin with asystole, which speaks for advanced underlying heart disease.

PTE (pulmonary thromboembolism) is often a cause of cardiac arrest, usually not a direct consequence. However, indirectly, cardiac arrest survivors, in general, due to the severity of their health conditions and bed restriction, could be more prone to develop thrombosis and, consequently, PTE. However, as a rule, post-stop patients are commonly using anticoagulants, which reduces the risk of thrombosis and, consequently, also of PTE.

Asystole is found initially in only about 28% of cardiac arrest cases in hospitalized patients, [ 3] but only 15% of these survive, even with the benefit of an intensive care unit, with the rate being lower (6%) for those already prescribed drugs for high blood pressure. [ 4]

Any condition that causes sudden cardiac arrest (SCA) or severe disruption of the cardiac electrical system can lead to asystole. 1 Patients with SCA caused by any of the following are treatable 2: Toxins.