Which of the following is caused due to spasm of the coronary artery?

AIIMS Raipur - 2017 (Shift-3)

Pharmacology

Easy

Appeared in: AIIMS Raipur - 2017 (Shift-3)

Explanation

Variant angina, also called Prinzmetal's angina, is directly caused by a sudden spasm in a coronary artery.
This spasm temporarily constricts the artery, leading to a transient reduction in blood flow to the heart muscle (myocardium).
Unlike effort-induced angina, these episodes of chest pain characteristically occur when the person is at rest, often between midnight and early morning.

Option A: This is caused by a fixed narrowing of the coronary arteries due to atherosclerosis. The chest pain is triggered by increased heart workload (e.g., physical exertion), not by a primary arterial spasm.
Option C: This is typically caused by the rupture of an atherosclerotic plaque followed by the formation of a blood clot (thrombus) that causes an incomplete blockage. While vasospasm can be a contributing factor, the primary mechanism is plaque rupture.
Option D: This condition involves the death of heart muscle tissue resulting from a complete and prolonged blockage of a coronary artery, usually by a thrombus. It is the end result of severe ischemia, not just a transient spasm.

Visual 1: Diagram - A comparison showing a normal coronary artery, an artery undergoing spasm (as in Variant Angina), and an artery with a fixed atherosclerotic plaque (as in Stable Angina).
Visual 2: ECG Strip - An example of transient ST-segment elevation seen during an episode of Prinzmetal's angina, which resolves as the spasm ceases.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Pathophysiology and Types of Angina Pectoris as background academic context rather than a clinical decision trigger.
Differentiating the cause of angina is critical for treatment. Variant angina is treated primarily with vasodilators like calcium channel blockers and nitrates. Beta-blockers, a common treatment for stable angina, can potentially worsen coronary spasm and are generally avoided.
A key nursing assessment is to document the characteristics of the patient's chest pain, including triggers (rest vs. exertion), timing (time of day), and response to medication, to help diagnose the underlying type of angina.
What if? If a patient presents with chest pain and ST-segment elevation on ECG, it is treated as an acute MI until proven otherwise. However, if the ST elevation resolves quickly with nitroglycerin and cardiac enzymes are negative, it strongly suggests variant angina.

How to Approach the Question

Step 1: Identify the core concept in the question stem, which is 'spasm of the coronary artery'.
Step 2: Systematically review the pathophysiology of each option provided.
Step 3: Recall that Stable Angina is caused by fixed stenosis and is triggered by exertion.
Step 4: Recall that Unstable Angina and Myocardial Infarction are primarily caused by plaque rupture and thrombosis.
Step 5: Connect the keyword 'spasm' directly to its definition, which is the hallmark of Variant (Prinzmetal's) Angina.

Concept Tested & Keywords

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