['Several prognostic factors have been identified in patients with vasospastic angina; however, factors that would predict potentially fatal cardiac arrest during the period between the onset of angina and its definitive diagnosis remain unknown. We investigated the predictive value of the clinical findings that are available when a patient is hospitalized after a cardiac arrest but before a definitive diagnosis of vasospastic angina is made.', 'We compared the clinical findings in 11 patients who experienced cardiac arrest before vasospastic angina was definitively diagnosed (group I) with 81 patients with vasospastic angina without cardiac arrest (group II). The definitive diagnosis of vasospastic angina was made on the basis of results of coronary spasm provocation test or ECGs during spontaneous attacks, or both.', 'The incidence of angina-linked syncope was significantly higher in group I than in group II (six out of 11 versus nine out of 81, P < 0.005). Significantly fewer group I patients were receiving calcium antagonists than group II patients (three out of 11 versus 63 out of 81, P < 0.005). Serious arrhythmias were significantly more common in group 1 than in group II (seven out of 11 versus 12 out of 81, P < 0.005). Logistic regression analysis of the eight clinical variables available when first seen in the hospital indicated that angina-linked syncope and the lack of calcium antagonist therapy were independently related to risk of cardiac arrest.'] Do angina-linked syncope and lack of calcium antagonist therapy predict cardiac arrest before definitive diagnosis of vasospastic angina?