Coronary spasm: It’s common, but it’s still unsolved

Table 1 Recent topics and unsolved problems regarding coronary spasm

	Previously reported or established	Recent topics	Unsolved problems
Mechanism	Abnormal autonomic nervous system Endothelial dysfunction Hyperreactivity of the coronary smooth muscle	Inflammation of perivascular components
	Others Inheritance Magnesium deficiency	Specific anatomy of the coronary artery (myocardial bridge)	Different mechanisms in men and women Is there a racial difference in coronary spasm?
Diagnosis	Non-invasive: Holter ECG	Malondialdehyde-modified low-density lipoprotein Exercise ECG	Is a biochemical marker for coronary spasm present?
	Invasive: SPT	Higher doses of ACh infusions Sequential SPT SPT using a pressure wire Second SPT despite of negative results of first SPT	Detailed SPT protocol using EM Are higher doses of ACh for SPT being used? Does SPT positivity continue for decades?
Treatment	Life style Stop smoking Pharmacological Calcium-channel blockers Sublingual nitroglycerin during attacks Combination of coronary vasodilators	Cilostazol Statin Aspirin	Treatment of intractable VSA Which combinations of coronary vasodilator are the most effective?
	Non-pharmacological	Use of ICD in VSA patients with cardiac arrest Cardiac rehabilitation	Which is effective in preventing adverse events in VSA patients with cardiac arrest: use of ICD or aggressive medical therapy? Treatment of accompanying microvascular angina

ACh: Acetylcholine; ECG: Electrocardiogram; EM: Ergonovine maleate; ICD: Implantable cardioverter defibrillator; SPT: Spasm provocation test; VSA: Vasospastic angina; SPT: Spasm provocation test.