Clinical Overview
The Killip Classification is a classic, rapid bedside tool used to assess patients presenting with acute myocardial infarction (AMI). Despite being developed in the 1960s, it remains a cornerstone of acute coronary syndrome triage, predicting 30-day mortality based entirely on physical exam findings.
Pathophysiology & Evidence
When a myocardial infarction occurs, a portion of the heart muscle dies, leading to sudden left ventricular pump failure. This failure causes blood to back up into the pulmonary circulation.
- Class II: Mild backup causes fluid to leak into the lung bases, heard as rales (crackles).
- Class III: Severe backup causes overt pulmonary edema.
- Class IV: The pump failure is so severe that systemic blood pressure collapses (cardiogenic shock), cutting off perfusion to the kidneys and brain.
Formula Breakdown
Class = I through IV based on physical exam
Mortality risk scales dramatically from ~6% in Class I to >80% in historical cohorts for Class IV (though modern interventions like primary PCI have lowered this absolute risk).