Acute Coronary Syndrome: Coronary Vasospasm

Acute Coronary Syndrome: Coronary Vasospasm

Description

Ø Spontaneous episodes of chest pain due to coronary artery vasospasm in absence of increase in myocardial oxygen demand in either normal or diseased coronary vessels

Ø Also known as Prinzmetal angina or variant angina

Ø Most common in younger patients and men

Ø Occurs in patients without other cardiac risk factors

Ø Risk factors:

o Smoking

o Hyperinsulinemia

o Insulin resistance

Ø Associated with minimal coronary artery disease:

o Usually has normal coronary angiogram

Etiology

• Abnormal vasodilator function in coronary arteries
• Focal coronary artery vasospasm
• Often adjacent to or at the site of fixed stenoses
• Unopposed alpha sympathetic stimulation
• Sympathetic stimulation by endogenous hormones may cause vasoconstriction
• Hypersensitivity of coronary arteries due to mediators of vasoconstriction
• May or may not be associated with a fixed coronary lesion

Diagnosis

Signs and Symptoms

• Chest pain:
• Retrosternal
• Radiates to neck, jaw, left shoulder, or arm
• Occurs at rest
• Palpitations
• Presyncope or syncope
• Associated with migraine headaches and Raynaud disease in a minority of patients
• May occur during cold weather or stress
• May be prolonged in duration compared to typical angina
• May be elicited by hyperventilation
• May be relieved by exercise
• Circadian pattern, most commonly in early morning

Tests

ECG:

• Transient ST-segment elevation is characteristic
• May be followed by ST depression or T-wave inversion
• May have associated arrhythmia during coronary spasm
• Heart block with right coronary artery spasm
• Ventricular tachycardia with LAD spasm

Lab

• CK-MB and troponin I or T
• Toxicologic screen:
• Helpful if cocaine is suspected as etiology of chest pain

Imaging

• Chest radiograph:
• May be helpful to rule out other etiologies such as pneumonia, pneumothorax, or aortic dissection
• Thallium scintigraphy may be useful to localize area of spasm

Diagnostic Procedures/Surgery

• Exercise stress testing:
• Helpful only if there are underlying fixed stenoses
• Coronary angiography:
• Mild atherosclerosis is often the norm
• Provocative test with ergonovine, acetylcholine, or hyperventilation will induce coronary spasm

Differential Diagnosis

• Angina pectoris
• Anxiety and panic disorders
• Aortic dissection
• Esophageal rupture
• Esophageal spasm
• Esophagitis
• Gastroesophageal reflux
• Mitral valve prolapse
• Musculoskeletal chest pain
• Myocardial infarction
• Peptic ulcer disease
• Pericarditis
• Pneumothorax
• Pulmonary embolism

Treatment

Pre Hospital

Treat as any other acute coronary syndrome

Initial Stabilization

• IV access
• Oxygen
• Cardiac monitoring
• Vital signs and oxygen saturation

ED Treatment

• All patients with chest pain in which cardiac ischemia is a consideration should receive an aspirin upon arrival to the ED:
• Possibility of actually increasing severity of episodes in Prinzmetal angina due to inhibiting biosynthesis of naturally-occurring coronary vasodilator prostacyclin
• Nitroglycerin should then be administered and is appropriate to help relieve both ischemic and vasospastic chest pain.
• A trial of calcium-channel blockers is indicated if clinical history is consistent with coronary vasospasm
• Heparin and beta-blockers are not helpful:
• Beta-blockers may actually be detrimental due to unopposed alpha-mediated vasoconstriction.

Medication (Drugs)

• Aspirin: 325 mg PO
• Diltiazem: 30-60 mg PO
• Nitroglycerin, either:
• 0.4 mg sublingual
• 10-20 mcg/min IV, titrating to effect
• 1-2 inches of nitropaste
• Verapamil: 40-80 mg PO

Follow-Up

Disposition

Admission Criteria

• New-onset chest pain
• Rest chest pain (by definition most patients with coronary vasospasm)
• Accelerated chest symptoms

Discharge Criteria

Stable (chronic chest pain)

References

1. Braunwald E. Unstable angina: an etiologic approach to management [editorial]. Circulation. 1998;98:2219-2222.
2. Crea F, Kaski JC, Maseri A. Key references on coronary artery spasm. Circulation. 1994;89:2442-2446.
3. Gersh BJ, Braunwald E, Bonow RO. Chronic coronary artery disease. In: Braunwald E, ed. Heart disease: a textbook of cardiovascular disease. 6th ed. Philadelphia: WB Saunders, 2001;1324-1328.
4. Mayer S, Hillis LD. Prinzmetal's variant angina. Clin Cardiol. 1998;21:243-246.
5. Orford JL. Coronary artery vasospasm. Med J. 2001;2:111.
6. Prinzmetal M, Kennamer R, Merliss R. A variant form of angina pectoris. Am J Med. 1959;27:375-388.
Codes
ICD9-CM

413.1