Cardiology - Acs
Acute coronary syndromes (ACS)
* ACS = life threatening conditions that are continuum ranging from unstable angina to large AMI * All have common underlying pathology: * Plaque rupture * Thrombosis * Inflammation
Pathogenesis: * Majority result from disruption of atherosclerotic plaque platelet aggregation intracoronary thrombus formation * Thrombus transforms region of plaque narrowing severe or complete occlusion marked imbalance between O2 supply + demand * Partially occlusive thrombus is usual cause of: * Unstable angina * Non ST elevation MI (NSTEMI) * Both very similar – latter has myocardial necrosis (whereas unstable angina only ischemia) * Complete obstruction more severe ischemia + larger amount of necrosis ST elevation MI (STEMI)
Acute coronary syndromes. Following disruption of a vulnerable plaque, patients experience ischemic discomfort resulting from a reduction of flow through the affected epicardial coronary artery. The flow reduction may be caused by a completely occlusive thrombus (right) or subtotally occlusive thrombus (left). Patients with ischemic discomfort may present with or without ST-segment elevation. Of patients with ST-segment elevation, the majority (wide red arrow) ultimately develop a Q wave on the ECG (QwMI), while a minority (thin red arrow) do not develop Q wave and, in older literature, were said to have sustained a non-Q-wave MI (NQMI). Patients who present without ST-segment elevation are suffering from either unstable angina or a non-ST-segment elevation MI (NSTEMI) (wide green arrows), a distinction that is ultimately made on the presence or absence of a serum cardiac marker such as CKMB or a cardiac troponin detected in the blood. The majority of patients presenting with NSTEMI do not develop a Q wave on the ECG; a minority develop a QwMI (thin green arrow).
* Uncommon causes of ACS:
* Suspect uncommon causes in young pts with
* ACS = life threatening conditions that are continuum ranging from unstable angina to large AMI * All have common underlying pathology: * Plaque rupture * Thrombosis * Inflammation
Pathogenesis: * Majority result from disruption of atherosclerotic plaque platelet aggregation intracoronary thrombus formation * Thrombus transforms region of plaque narrowing severe or complete occlusion marked imbalance between O2 supply + demand * Partially occlusive thrombus is usual cause of: * Unstable angina * Non ST elevation MI (NSTEMI) * Both very similar – latter has myocardial necrosis (whereas unstable angina only ischemia) * Complete obstruction more severe ischemia + larger amount of necrosis ST elevation MI (STEMI)
Acute coronary syndromes. Following disruption of a vulnerable plaque, patients experience ischemic discomfort resulting from a reduction of flow through the affected epicardial coronary artery. The flow reduction may be caused by a completely occlusive thrombus (right) or subtotally occlusive thrombus (left). Patients with ischemic discomfort may present with or without ST-segment elevation. Of patients with ST-segment elevation, the majority (wide red arrow) ultimately develop a Q wave on the ECG (QwMI), while a minority (thin red arrow) do not develop Q wave and, in older literature, were said to have sustained a non-Q-wave MI (NQMI). Patients who present without ST-segment elevation are suffering from either unstable angina or a non-ST-segment elevation MI (NSTEMI) (wide green arrows), a distinction that is ultimately made on the presence or absence of a serum cardiac marker such as CKMB or a cardiac troponin detected in the blood. The majority of patients presenting with NSTEMI do not develop a Q wave on the ECG; a minority develop a QwMI (thin green arrow).
* Uncommon causes of ACS:
* Suspect uncommon causes in young pts with