Multifocal spasm with acetylcholine in Prinzmetal angina

Abstract

A 60-year-old female patient with Prinzmetal angina and a single non-critical (<50%) focal obstruction in the right coronary artery was referred for percutaneous coronary intervention. Coronary angiography with provocative testing using incremental doses of acetylcholine demonstrated diffuse mild vasoconstriction and multifocal hyperreactive vasoconstriction in apparently normal coronary segments but not at the site of the nonsignificant obstruction. We refrained from intervention and advised avoidance of β-blockade, and continuation of medical therapy with nitrates and calcium antagonists. (Neth Heart J 2008;16: 134-6.)Keywords: Prinzmetal angina, acteylcholine, multifocal spasm A 60-year-old female was awakened early one morning with extreme chest discomfort radiating to both her arms. She felt weak and light-headed and she fainted when she tried to get up. She regained consciousness quickly without sequelae. Upon arrival at the hospital she was without symptoms. The ECG was normal. Physical examination revealed no abnormalities. During her hospital stay she had two more early morning episodes of chest discomfort with inferior ST-segment elevation and second degree as well as complete AV block (figure 1). She is a cigarette smoker with no other classical risk factors. Coronary angiography in the absence of ischaemia revealed a normal left coronary artery and a mild fixed coronary obstruction in the distal segment of the right coronary artery (RCA). The diagnosis of Prinzmetal angina was made. 1 She was treated with calcium antagonists and nitrates. She was referred for percutaneous coronary intervention (PCI) of the non-critical obstruction ( figure 2A), but we decided to perform a provocative test with selective intracoronary infusions of acetylcholine in incremental doses. 2 Infusion of acetylcholine at the third dose level (50 µg) induced diffuse mild vasoconstriction and multifocal hyperreactive vasoconstriction (spasm) in apparently normal coronary segments but not at the site of the alleged culprit lesion (figure 2B). The mild constriction and spasms were promptly resolved by intracoronary nitroglycerin ( figure 2C). We refrained from PCI and advised an intensification of the therapy with calcium antagonists, nitrates, aspirin and statins, and avoidance of β-blockade and smoking. DiscussionThis patient presented with classical Prinzmetal (variant) angina. She is a cigarette smoker with no other classical risk factors. 3 As with acute myocardial infarction, a circadian periodicity is present with attacks recurring at approximately the same time in the 24-hour period. [4][5][6] The attacks are severe and are accompanied by syncope, inferior ST-segment elevation and transient AV block, suggestive of acute transient occlusion of the RCA, a frequent site in Prinzmetal angina. 7 Coronary angiography showed a single non-critical obstruction in the distal part of the RCA. Intuitively we held spasm at this site responsible for the attacks, but later we realised that spasm may develop at sites other than the fixed...

Endothelial dysfunction: the reversible coronary disease

“…The normally negligible vasoconstricting effect of acetylcholine becomes more dominant in endothelial dysfunction. 2,3 This phenomenon is used for diagnostic purposes, when intracoronary injections of acetylcholine are given with increasing doses.…”

“…Besides its other antithrombotic and anti-inflammatory effects, NO also regulates the production of growth factors, the vasoconstrictor endothelin and vasodilators, such as prostacyclin. 1,2 NO release is stimulated by high shear stress, by increase in myocardial oxygen demand, by sympathetic activation and by both acetylcholine and bradykinin. Acetylcholine itself stimulates the contraction of smooth muscle cells.…”

Spontaneous resolution of mid-segment coronary vasospasm previously unresponsive to intracoronary nitroglycerin

“…While often producing vasodilatation, angiographic dye has also been reported to cause coronary vasospasm [3]. Intracoronary administration of vasodilators is the suggested acute treatment for coronary vasospasm in the catheterisation laboratory [4]. Nitroglycerin in doses of 100-200 μg bolus should be the first agent used.…”