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Wellens' syndrome is an electrocardiographic manifestation of critical proximal left anterior descending (LAD) coronary artery stenosis in people with unstable angina. Originally thought of as two separate types, A and B, it is now considered an evolving wave form, initially of biphasic T wave inversions and later becoming symmetrical, often ...
unstable angina; after percutaneous transluminal coronary angioplasty (PTCA) after cardiac surgery 'neurogenic' stunned myocardium following an acute cerebrovascular event such as a subarachnoid hemorrhage; in patients undergoing chronic hemodialysis, chronic myocardial stunning may lead to heart failure
The pathophysiology of unstable angina is controversial. Previously, unstable angina was assumed to be angina pectoris caused by disruption of an atherosclerotic plaque with partial thrombosis and possibly embolization or vasospasm leading to myocardial ischemia. [9] [10] However, sensitive troponin assays reveal rise of cardiac troponin in the ...
In unstable angina, symptoms may appear on rest or on minimal exertion. [6] The symptoms can last longer than those in stable angina, can be resistant to rest or medicine, and can get worse over time. [8] [10] Though ACS is usually associated with coronary thrombosis, it can also be associated with cocaine use. [11]
Variant angina differs from stable angina in that it commonly occurs in individuals who are at rest or even asleep, whereas stable angina is generally triggered by exertion or intense exercise. Variant angina is caused by vasospasm, a narrowing of the coronary arteries due to contraction of the heart's smooth muscle tissue in the vessel walls. [3]
This interferes with the blood flow to the heart muscle and causes symptoms otherwise indistinguishable from unstable angina. [8] It is possible that even in people without direct evidence of allergy, the allergic response may be playing a role in acute coronary syndrome: markers of mast cell activation are found in people with ACS. [8]
Angina may present typically with classic symptoms or atypically with symptoms less often associated with heart disease. [19] Atypical presentations are more common in women, diabetics, and elderly individuals. [8] Angina may be stable or unstable. Unstable angina is most often associated with emergent, acute coronary syndromes. [20]
Coronary vasospasm refers to when a coronary artery suddenly undergoes either complete or sub-total temporary occlusion. [1]In 1959, Prinzmetal et al. described a type of chest pain resulting from coronary vasospasm, referring to it as a variant form of classical angina pectoris. [2]