Cardiovascular collapse is severe hypotension from acute cardiac dysfunction or loss of peripheral vasculature resistance resulting in cerebral hypoperfusion and loss of consciousness (See Table 306-1). This condition can be the result of a cardiac arrhythmia, severe myocardial or valvular dysfunction, loss of vascular tone, and/or acute disruption of venous return. When an effective circulation is restored spontaneously, patients present with syncope (see Chap. 21). In the absence of spontaneous resolution, then cardiac arrest occurs, ultimately resulting in death if resuscitation attempts are unsuccessful or not initiated. Underlying etiologies for cardiovascular collapse include benign conditions, such as neurocardiogenic syncope, but also life-threatening conditions including: ventricular tachyarrhythmias; severe bradycardia; severely depressed myocardial contractility, as with massive acute myocardial infarction (MI) or pulmonary embolus; and other catastrophic events interfering with cardiac function such as myocardial rupture with cardiac tamponade or papillary muscle rupture with torrential mitral regurgitation.
TABLE 306-1Distinction between Cardiovascular Collapse, Cardiac Arrest, and Death ||Download (.pdf) TABLE 306-1 Distinction between Cardiovascular Collapse, Cardiac Arrest, and Death
|TERM ||DEFINITION ||QUALIFIERS ||MECHANISMS |
|Cardiovascular collapse ||Sudden loss of effective circulation due to cardiac and/or peripheral vascular factors that may reverse spontaneously (e.g., neurocardiogenic syncope, vasovagal syncope) or require interventions (e.g., cardiac arrest). ||Broad term that includes cardiac arrest and transient events that characteristically revert spontaneously presenting as syncope. ||Same as cardiac arrest, plus vasodepressor syncope or other causes of transient loss of blood flow. |
|Cardiac arrest ||Abrupt cessation of cardiac function resulting in loss of effective circulation that may be reversible by prompt emergency medical intervention but will lead to death in its absence. ||Rare spontaneous reversions; likelihood of successful intervention relates to mechanism of arrest, clinical setting, availability of emergency medical services, and prompt return of circulation. ||Ventricular fibrillation, ventricular tachycardia, asystole, bradycardia, pulseless electrical activity, noncardiac mechanical factors (e.g., pulmonary embolism). |
|Sudden cardiac death ||Sudden unexpected death attributed to cardiac arrest, which if witnessed occurs within 1 h of symptom onset. ||In unwitnessed cases, the definition is often expanded to include unexpected deaths where the subject was documented to be well within the preceding 24 h. ||Same as cardiac arrest. |
Sudden cardiac arrest (SCA) refers to an abrupt loss of cardiac function resulting in complete cardiovascular collapse due either to an acute life-threatening cardiac arrhythmia or abrupt loss of myocardial pump function that requires emergency medical intervention for restoration of effective circulation. Most SCAs occur outside the hospital, and fewer than 10% of these victims survive to be discharged from the hospital despite undergoing attempted resuscitation by emergency medical services (EMS). For those that die prior to hospital admission, a cardiovascular cause for the arrest ...