Variant or Prinzmetal’s Angina

KEY FEATURES

ESSENTIALS OF DIAGNOSIS

• Chest pain at rest, which does not occur with exercise or emotional stress

• Transient ST-segment elevation on ECG

• Resolution of pain and ECG changes spontaneously or after nitroglycerin administration

• Focal or diffuse coronary arterial spasm may be demonstrated on coronary angiography

GENERAL CONSIDERATIONS

• Much more common in Japan, Korea, and Italy than in the United States

• On coronary angiography, sites of vasospasm usually have at least minimal atherosclerosis as detected by intravascular ultrasound

• Precise mechanism is not clear, although the following is known:

  • – An imbalance of endothelium-derived vasoconstrictor versus dilators

• Cigarette smoking is an important risk factor

• Patients with this disorder are younger than patients with angina secondary to classic atherosclerosis

• Myocardial infarction (MI) and sudden cardiac death may occur

• Rare cases may develop this disorder after coronary artery bypass graft (CABG) surgery

• It may occur in association with aspirin-induced asthma

• Alcohol withdrawal may provoke an attack

• Chemotherapy may provoke variant angina (5-fluorouracil and cyclophosphamide)

CLINICAL PRESENTATION

SYMPTOMS AND SIGNS

• Severe chest pain unlike angina

• Syncope

• Clustering of chest pain between midnight and 8:00 AM

• Normal exercise capacity and rarely, if ever, chest pain on exertion

PHYSICAL EXAM FINDINGS

• Usually normal between episodes

  • – Previous MI may change clinical examination

• During chest pain, an S₄ may be heard

DIFFERENTIAL DIAGNOSIS

• Unstable chronic ischemic heart disease

• MI

• Pericarditis

• Other conditions mimicked on ECG, such as early repolarization

DIAGNOSTIC EVALUATION

LABORATORY TESTS

• CBC, metabolic panel

• Cardiac biomarkers during acute episodes

ELECTROCARDIOGRAPHY

• ECG shows transient ST elevation suggestive of acute MI during pain

• Ambulatory ECG monitoring may reveal asymptomatic ST elevation

IMAGING STUDIES

• Echocardiography may demonstrate left ventricular wall motion abnormalities during pain

DIAGNOSTIC PROCEDURES

• Coronary angiogram

• Fixed stenosis of a proximal vessel may be seen in the majority of patients

• Diagnostic of the condition are:

  • – Normal coronary angiogram in the absence of ischemia

  • – Focal or diffuse coronary spasm during ischemia

• Right coronary artery spasm is more common than left

• Spasm at different sites or sequential involvement of different sites may be noted

• Acetylcholine provocation test may be helpful

• Ergonovine provocation may be helpful

TREATMENT

CARDIOLOGY REFERRAL

• All patients should be referred to a cardiologist

HOSPITALIZATION CRITERIA

• Hospitalization during acute episodes

MEDICATIONS

• Sublingual nitroglycerin for acute attacks

• Long-acting nitrates

• Calcium channel blockers

• Percutaneous or surgical revascularization is rarely ...