Does print metal variant angina cause ST segment changes visible during episodes of chest pain, specifically referring to Prinzmetal's (variant) angina?

From the Guidelines

Yes, Prinzmetal variant angina does cause ST segment changes that are visible during chest pain episodes. These ST segment elevations typically occur during the angina attack and resolve when the pain subsides, as noted in the guidelines for managing patients with unstable angina/non-ST-elevation myocardial infarction 1. The most recent and highest quality study, from 2013, further supports this, indicating that ST-segment elevation implies transmural focal ischemia associated with complete or near-complete coronary occlusion of an epicardial coronary artery in the absence of collateral circulation 1.

Key Points

• Prinzmetal variant angina results from coronary artery spasm that temporarily reduces blood flow to the heart muscle, causing transient myocardial ischemia.
• This ischemia manifests as ST segment elevation on an electrocardiogram (ECG), which is most likely to be captured if an ECG is performed during the chest pain episode.
• The ST elevations in Prinzmetal angina can be difficult to distinguish from those seen in acute myocardial infarction, making additional testing such as coronary angiography necessary to confirm the diagnosis, as recommended by guidelines 1.
• Treatment typically involves calcium channel blockers and nitrates to prevent coronary spasm and relieve symptoms, with the choice of treatment influenced by the presence of coronary artery lesions and risk factors 1.

Diagnostic Approach

The diagnostic approach for Prinzmetal variant angina includes:

• Recording of transient ST-segment elevation during an episode of chest pain, which can be done through continuous 12-lead ECG monitoring or a treadmill exercise test 1.
• Coronary angiography to visualize the coronary arteries and assess for any obstructive lesions, as well as to directly observe coronary spasm during the procedure 1.
• Other tests such as a 2-dimensional echocardiogram or the injection of a nuclear marker at the time of chest pain may help document the presence of transmural ischemia 1.

Treatment

Treatment with nitrates and calcium channel blockers is recommended for patients with variant angina, especially when the coronary angiogram shows no or nonobstructive coronary artery lesions, with risk factor modification also being crucial 1. The choice of treatment should be guided by the individual patient's risk factors and the presence of atherosclerotic lesions, which may indicate a higher risk 1.

From the Research

Print Metal Variant Angina and ST Segment Changes

• Print metal variant angina, also known as Prinzmetal's angina, is a condition characterized by transient reduction in luminal diameter of a coronary artery, resulting in spontaneous and often recurrent episodes of angina with electrocardiography (ECG) findings consistent with ST elevation 2, 3, 4.
• The diagnosis of Prinzmetal's angina is made by observing transient ST-segment elevation during the attack of angina, which is a key feature of this condition 2, 4.
• ECG changes associated with ST-segment elevation in Prinzmetal's angina include increased height of the R wave, coincident S-wave diminution, upsloping TQ, and alternans of the elevated ST-segment and negative T wave deepness 4.
• The presence of arrhythmias, especially ventricular arrhythmias, is very frequent during Prinzmetal's angina crises, and is related to the duration of episodes, degree of ST-segment elevation, and presence of ST-T wave alternans 4.
• ST segment changes are visible during chest pain episodes in patients with Prinzmetal's angina, and are a key diagnostic feature of this condition 2, 3, 4, 5, 6.

Clinical Considerations

• Prinzmetal's angina is a well-documented but under-recognized etiology of recurrent ST elevation myocardial infarction, and should be considered in patients with both typical and atypical cardiovascular risk profiles 3.
• The incidence of Prinzmetal's angina is lower than it was 50 years ago, due to treatment with calcium channel blockers and decreased smoking habits 4.
• Medical therapy for Prinzmetal's angina classically employs vasodilator drugs, including nitrates and calcium channel blockers, and beta-blockers and large doses of aspirin are contraindicated in this condition 2, 5, 6.