- Published on
Emergency and Acute Medicine – Acute Coronary Syndrome: Coronary Vasospasm (Prinzmetal / Variant Angina)
Overview and Pathophysiology
Coronary vasospasm causes spontaneous episodes of myocardial ischemia due to transient constriction of coronary arteries without an increase in myocardial oxygen demand. Also known as Prinzmetal or variant angina, it was first described in 1959 and most commonly affects younger patients and men. Many patients lack traditional coronary artery disease (CAD) or classic cardiac risk factors. Cigarette smoking is the strongest association, present in up to three-quarters of cases. Hypertension, hypercholesterolemia, diabetes mellitus, and cocaine use further increase risk.
Mechanisms and Etiology
The underlying mechanism is abnormal coronary vasomotor regulation, typically related to endothelial dysfunction. Vasospasm may involve epicardial arteries, the microvasculature, or both, and can be categorized as focal (localized to a single segment), multifocal (multiple segments of one artery), or multivessel (involving different coronary arteries). Proposed contributors include unopposed α-adrenergic sympathetic stimulation, altered autonomic tone (including increased vagal influence or abrupt vagal withdrawal), hypersensitivity to vasoconstrictor mediators, impaired nitric oxide signaling, and increased Rho-kinase activity in vascular smooth muscle.
Clinical Presentation
Chest pain is classically retrosternal, may radiate to the neck, jaw, left shoulder, or arm, and typically occurs at rest, often at night or in the early morning. Episodes may be prolonged compared with exertional angina and can be associated with palpitations, presyncope, or syncope. Some patients have comorbid migraine headaches or Raynaud phenomenon. Symptoms may be triggered by cold exposure, emotional stress, hyperventilation, or—less commonly—exercise, and often demonstrate a circadian pattern.
Initial Evaluation
The physical examination is usually unrevealing. An ECG is mandatory in all suspected cases. Further testing depends on the clinical context, risk profile, and response to therapy.
Electrocardiography and Testing
During active spasm, the ECG characteristically shows transient, often marked ST-segment elevation, frequently with reciprocal changes. This may be followed by ST depression or T-wave inversion after resolution. Dysrhythmias can occur during spasm, including ventricular tachycardia (often with LAD involvement) or heart block (commonly with right coronary artery spasm).
Cardiac biomarkers (troponin, CK-MB) are usually normal but should be obtained to assess for myocardial injury, especially if symptoms are prolonged. Toxicology screening is helpful when cocaine use is suspected. Chest radiography assists in excluding alternative diagnoses (e.g., pneumothorax, pneumonia, aortic pathology). Noninvasive imaging is most informative when paired with provocative testing. Coronary angiography often reveals mild or absent atherosclerosis; provocative testing with acetylcholine is the diagnostic gold standard in selected patients.
Differential Diagnosis
Consider typical angina, myocardial infarction, aortic dissection, cocaine-associated chest pain, esophageal spasm or rupture, GERD, pericarditis, pulmonary embolism, pneumothorax, Takotsubo cardiomyopathy, anxiety disorders, and musculoskeletal pain.
Emergency Management
Prehospital and initial ED care should follow standard ACS protocols: IV access, cardiac monitoring, oxygen as needed, and vital sign surveillance. Nitroglycerin is effective for symptom relief in vasospastic and ischemic pain and should be administered.
All patients with possible ischemic chest pain typically receive aspirin on arrival; however, aspirin may paradoxically worsen vasospasm by inhibiting prostacyclin synthesis. Despite this, aspirin is commonly given until vasospasm is confirmed. Calcium-channel blockers (CCBs) are first-line therapy for suspected vasospasm. Heparin and β-blockers are not beneficial in isolated vasospasm; β-blockers may worsen symptoms due to unopposed α-mediated vasoconstriction and should be avoided, particularly with cocaine exposure.
Pharmacologic Therapy
First-line treatment includes CCBs (e.g., diltiazem or verapamil) and long-acting nitrates. Despite therapy, 30–40% of patients experience recurrence. Second-line options include α-blockers and statins. Percutaneous intervention for fixed lesions is controversial and may provoke spasm elsewhere. Pacemaker implantation may be indicated for recurrent syncope or AV block related to vasospasm.
Disposition and Follow-Up
Patients with new-onset chest pain or positive biomarkers/provocative testing should be admitted. Many stable patients can be evaluated safely in a chest pain observation unit. Discharge may be appropriate for patients with chronic symptoms and a negative ischemic evaluation. Cardiology follow-up within 7 days is recommended.
Clinical Pearls and Pitfalls
Five-year survival approaches 95%. Most patients lack traditional CAD risk factors aside from smoking. Calcium-channel blockers are the cornerstone of therapy, yet recurrence is common. Vasospasm can mimic STEMI; true infarction usually occurs in those with underlying atherosclerosis. Avoid β-blockers, which can exacerbate spasm. Prolonged episodes may lead to malignant arrhythmias or sudden death.
Overview and Pathophysiology
Coronary vasospasm causes spontaneous episodes of myocardial ischemia due to transient constriction of coronary arteries without an increase in myocardial oxygen demand. Also known as Prinzmetal or variant angina, it was first described in 1959 and most commonly affects younger patients and men. Many patients lack traditional coronary artery disease (CAD) or classic cardiac risk factors. Cigarette smoking is the strongest association, present in up to three-quarters of cases. Hypertension, hypercholesterolemia, diabetes mellitus, and cocaine use further increase risk.
Mechanisms and Etiology
The underlying mechanism is abnormal coronary vasomotor regulation, typically related to endothelial dysfunction. Vasospasm may involve epicardial arteries, the microvasculature, or both, and can be categorized as focal (localized to a single segment), multifocal (multiple segments of one artery), or multivessel (involving different coronary arteries). Proposed contributors include unopposed α-adrenergic sympathetic stimulation, altered autonomic tone (including increased vagal influence or abrupt vagal withdrawal), hypersensitivity to vasoconstrictor mediators, impaired nitric oxide signaling, and increased Rho-kinase activity in vascular smooth muscle.
Clinical Presentation
Chest pain is classically retrosternal, may radiate to the neck, jaw, left shoulder, or arm, and typically occurs at rest, often at night or in the early morning. Episodes may be prolonged compared with exertional angina and can be associated with palpitations, presyncope, or syncope. Some patients have comorbid migraine headaches or Raynaud phenomenon. Symptoms may be triggered by cold exposure, emotional stress, hyperventilation, or—less commonly—exercise, and often demonstrate a circadian pattern.
Initial Evaluation
The physical examination is usually unrevealing. An ECG is mandatory in all suspected cases. Further testing depends on the clinical context, risk profile, and response to therapy.
Electrocardiography and Testing
During active spasm, the ECG characteristically shows transient, often marked ST-segment elevation, frequently with reciprocal changes. This may be followed by ST depression or T-wave inversion after resolution. Dysrhythmias can occur during spasm, including ventricular tachycardia (often with LAD involvement) or heart block (commonly with right coronary artery spasm).
Cardiac biomarkers (troponin, CK-MB) are usually normal but should be obtained to assess for myocardial injury, especially if symptoms are prolonged. Toxicology screening is helpful when cocaine use is suspected. Chest radiography assists in excluding alternative diagnoses (e.g., pneumothorax, pneumonia, aortic pathology). Noninvasive imaging is most informative when paired with provocative testing. Coronary angiography often reveals mild or absent atherosclerosis; provocative testing with acetylcholine is the diagnostic gold standard in selected patients.
Differential Diagnosis
Consider typical angina, myocardial infarction, aortic dissection, cocaine-associated chest pain, esophageal spasm or rupture, GERD, pericarditis, pulmonary embolism, pneumothorax, Takotsubo cardiomyopathy, anxiety disorders, and musculoskeletal pain.
Emergency Management
Prehospital and initial ED care should follow standard ACS protocols: IV access, cardiac monitoring, oxygen as needed, and vital sign surveillance. Nitroglycerin is effective for symptom relief in vasospastic and ischemic pain and should be administered.
All patients with possible ischemic chest pain typically receive aspirin on arrival; however, aspirin may paradoxically worsen vasospasm by inhibiting prostacyclin synthesis. Despite this, aspirin is commonly given until vasospasm is confirmed. Calcium-channel blockers (CCBs) are first-line therapy for suspected vasospasm. Heparin and β-blockers are not beneficial in isolated vasospasm; β-blockers may worsen symptoms due to unopposed α-mediated vasoconstriction and should be avoided, particularly with cocaine exposure.
Pharmacologic Therapy
First-line treatment includes CCBs (e.g., diltiazem or verapamil) and long-acting nitrates. Despite therapy, 30–40% of patients experience recurrence. Second-line options include α-blockers and statins. Percutaneous intervention for fixed lesions is controversial and may provoke spasm elsewhere. Pacemaker implantation may be indicated for recurrent syncope or AV block related to vasospasm.
Disposition and Follow-Up
Patients with new-onset chest pain or positive biomarkers/provocative testing should be admitted. Many stable patients can be evaluated safely in a chest pain observation unit. Discharge may be appropriate for patients with chronic symptoms and a negative ischemic evaluation. Cardiology follow-up within 7 days is recommended.
Clinical Pearls and Pitfalls
Five-year survival approaches 95%. Most patients lack traditional CAD risk factors aside from smoking. Calcium-channel blockers are the cornerstone of therapy, yet recurrence is common. Vasospasm can mimic STEMI; true infarction usually occurs in those with underlying atherosclerosis. Avoid β-blockers, which can exacerbate spasm. Prolonged episodes may lead to malignant arrhythmias or sudden death.
0 Comments
