The incidence and clinical implications of coronary artery spasm.

The total incidence of coronary artery spasm during coronary angiography has been reported to be between 0.26% and 0.93%. The rarity of this phenomenon has been invoked to minimize its clinical significance. Review of a one-year experience in our catheterization laboratory showed that coronary spasm occurred in eight of 274 coronary angiograms (2.93%). In three instances, spasm could not be ascribed to catheter tip irrigation, and was considered to be spontaneous. Since multiple factors during coronary arteriography might inhibit the occurrence of coronary spasm, it is believed that the incidence of spontaneous spasm may be higher than can be documented during angiography. Coronary spasm may have important clinical significance in various chest pain syndromes and greater methodical attention should be directed toward this phenomenon.     

Interaction between coronary artery stenosis and coronary microcirculation in ischemic heart disease

Summary The hallmark of ischemic heart disease is the presence of focal obstructions in the major coronary arteries. Classically, epicardial stenoses are thought to exert their pathogenetic role mainly through a limitation on maximal flow capacity in the distal vascular bed. Ischemia is thus thought to occur whenever oxygen consumption exceeds the flow availability. Although a number of experimental studies confirmed these assumptions, the adherence of this experimental model with the clinical observations is still far from being convincing. Evidence now exists that atherosclerosis causes more profound alterations in the regulation of myocardial perfusion, besides the hydraulic effects of epicardial obstructions. These alterations affect endothelial regulation of coronary vasomotor tone both in the large arteries and in the distal microcirculation. In agreement with this experimental evidence, an abnormal response to endothelium-mediated vasodilators has been reported in patients with coronary artery disease. Moreover, several studies also reported an abnormal response of atherosclerotic coronary microcirculation to atrial pacing tachycardia and dipyridamole, which are thought to be largely endothelium independent. An even more striking observation is the finding of an intense microvascular constrictor response in the myocardium, supplied by a severely stenotic coronary artery, to pacing-induced ischemia. This observation strongly suggests that coronary microcirculation might aggravate the flow reduction imposed by the epicardial stenosis, thus playing some role in the pathogenesis of ischemia. This phenomenon might reflect the presence of a primary abnormality of coronary microcirculation in patients with coronary artery disease or the existence of a pressure-oriented regulation of vascular tone which prevent trans-stenotic pressure drop by means of a heterogeneously distributed microcirculatory vasoconstriction.     

Electrocardiographic diagnosis of the coronary artery culprit site in ischemic heart disease.

The diagnostic accuracy of using electrocardiographic findings to identify affected vessels in cases of myocardial infarction and angina pectoris treated by percutaneous transluminal coronary angioplasty was assessed. From the anterior wall leads, ST segment elevation in leads I and aV(L) showed diagnostic accuracy (sensitivity, specificity and positive predictive value) in identifying proximal lesions of the left anterior descending coronary artery of 89%, 58% and 62%, and the diagnostic accuracy of the QS wave in V(1) was 62%, 83% and 72%, respectively. For the posterior wall leads, the corresponding values for the diagnosis of affected vessels based on R/S>1 in V(1) for the left circumflex coronary artery were 50%, 89% and 60%, respectively. The inferior wall leads with ST segment elevation in leads II, III and aV(F), and ST segment depression in aV(L), showed diagnostic accuracy for the right coronary artery of 90%, 90% and 92%, respectively. Bifurcation of the first diagonal branch, dominance of the posterior descending branch, the normal subtypes of the coronary artery and the occurrence of spontaneous recanalization may have influenced the accuracy of diagnosis. Adding a high lateral wall lead one intercostal space above V(4) and a posterior wall lead located one intercostal space below V(6) appeared to increase the diagnostic accuracy of detecting the coronary artery lesions responsible for myocardial ischemia.     

Significance of spasm in the pathogenesis of ischemic heart disease.

The role of coronary arterial vasospasm in the pathogenesis of ischemic heart disease is reviewed on the basis of investigations carried out in our laboratory. Patients were selected because they had angina either at rest or both at rest and during exercise. With continuous hemodynamic and electrocardiographic monitoring of these patients, as well as thallium-201 scintigraphy and coronary arteriography during ischemic episodes, we were able to demonstrate a vasospastic origin for the attacks. During anginal episodes, electrocardiographic changes were variable, with S-T segment elevation, S-T segment depression, a rise in T wave potential and pseudonormalization of inverted T waves corresponding to various distributions of myocardial ischemia in different patients and even in the same patient at different times. Increases in hemodynamic variables that control myocardial oxygen consumption never preceded the onset of ischemic episodes, which challenges the theory that the limitation of a possible increase in flow caused by critical organic stenosis is the only cause of myocardial ischemia. In some patients in whom myocardial infarction developed, the lesion was always found in the same area in which the vasospastic phenomena had been seen angiographically. Vasospasm led to serious arrhythmias in some patients. We therefore believe that independent of atherosclerosis or superimposed on it, vasospasm plays an important role in producing myocardial ischemia—angina, myocardial infarction and possibly sudden death. Elucidation of its mechanisms will lead to more appropriate therapy.     

Multivessel coronary artery spasm.

A 60-year-old patient with variant angina was shown to have myocardial ischemia in two different regions supplied by separate major coronary arteries. Neither artery had significant coronary atherosclerotic obstruction. Ventricular fibrillation was noted during ST-segment elevation in anteroseptal leads. The attacks of pain and arrhythmias disappeared during nifedipine therapy.     

Therapeutic implications of dynamic coronary stenosis in patients with single vessel coronary artery disease

Ten patients with proven single-vessel coronary artery disease and a positive exercise test for ischaemia were investigated to establish the importance and therapeutic implications of dynamic coronary stenosis in such patients. All patients interrupted their anti-anginal therapy and under took serial exercise testing in an attempt to identify variability in the ischaemic threshold. Ergonovine testing was performed in nine patients and all underwent 48 h of ambulatory ST segment monitoring while treatment was discontinued. Patients then entered a randomized double-blind study of atenolol and nifedipine; treadmill exercise testing and 48 h of ambulatory ST segment monitoring were performed at the end of each treatment phase. Six (60%) patients showed evidence of variability in coronary vasomotor tone four of whom developed significant ST segment changes during administration of ergonovine; a further two had greater than 30% variability in time to onset of ischaemia during serial treadmill exercise testing. Atenolol significantly increased the time to ischaemia on exercise testing, both in the group as a whole and in the subgroup with evidence of altered vasomotor tone when compared with no therapy, and led to a non-significant reduction in the frequency and duration of ischaemia during the patients' daily lives. Nifedipine, conversely, did not significantly increase time to ischaemia on exercise testing or reduce the frequency or duration of ambulatory ischaemia in either the whole group or the subgroup. With evidence of altered vasomotor tone when compared to no therapy however it was beneficial in terms of reduction in chest pain and requirement for glyceryl trinitrate during daily life.(ABSTRACT TRUNCATED AT 250 WORDS)     

High prevalence of coronary artery spasm in survivors of cardiac arrest with no apparent heart disease.

The pathogenesis of cardiac arrest in the absence of any apparent heart disease remains unclear. Based on the hypothesis that coronary spasm may be a cause of cardiac arrest in the absence of apparent heart disease, ergonovine testing and/or electrophysiologic studies (EPS) were performed to evaluate the cause of cardiac arrest. Fourteen patients resuscitated from cardiac arrest had no apparent heart disease. A spontaneous episode of angina with ST-segment elevation occurred in 4 patients while under observation. Ergonovine testing was performed in 9 patients, and coronary spasm was induced in 5. EPS were performed in 8 patients, including 3 patients with coronary spasm. No electrophysiologic abnormalities were found in the 3 patients with coronary spasm. Ventricular fibrillation was induced by programmed ventricular stimulation in 2 patients with documented ventricular fibrillation at the time of resuscitation. All but one of the patients with coronary spasm had chest pain preceding cardiac arrest or at least a history of chest pain at rest, while 4 of 5 patients without coronary spasm had no prodromal symptoms. Patients with coronary spasm had a good prognosis when treated with a Ca-antagonist and/or long-acting nitrate. In conclusion, coronary spasm is the most frequent cause of cardiac arrest in cardiac arrest survivors with no apparent heart disease. Ergonovine testing should be performed to evaluate the cause of cardiac arrest when patients have no apparent heart disease.     

Angiographic presentation of coronary artery spasm in heart transplant recipients

We describe the angiographic characteristics of coronary artery spasm observed in 12 out of 247 (4.9%) patients who underwent 808 coronary angiographies after heart transplantation. Coronary artery spasm was diagnosed when localized and reversible narrowing of the coronary lumen was identified. After coronary artery spasm identification all patients were followed-up clinically for a mean period of 5.1 years. Coronary artery spasm was documented 1-3 years after heart transplant. Coronary artery spasm affected 1 main coronary artery in 10 patients and 2 in 2 patients; in 3 patients 1 or more secondary branches were also affected. The right coronary artery was affected by coronary artery spasm in 8 patients and the anterior descending coronary artery in 6 patients. In 6 patients coronary artery spasm was mechanically induced by the catheter tip. The degree of luminal narrowing due to coronary artery spasm ranged from mild to almost complete occlusion. Coronary artery spasm appeared as a single tubular smooth and concentric stenosis in 8 patients, was discrete in 2 patients and multiple on the same vessel in 2 patients. In 1 patient coronary artery spasm was erroneously interpreted as an organic lesion and percutaneous transluminal coronary angioplasty was planned. During follow-up 3 patients out of 4 who had shown multiple coronary artery spasm died and 2 patients developed critical organic stenosis. In conclusion coronary artery spasm after heart transplant is less rare than commonly believed. Although it usually has a peculiar appearance, it can be misinterpreted as an organic lesion. Multiple coronary artery spasm appears to carry a poor prognosis.     

Stenting for coronary artery spasm.

We evaluated coronary stenting in nine patients with clinically severe, angiographically documented spasm refractory to aggressive pharmacologic management. No patient subsequently developed unstable ischemia requiring hospitalization as a consequence of recurrent spasm within the stent. Mechanisms of therapeutic failure included both persistent spasm and spasm in a different artery in one patient. Restenosis occurred in three patients who subsequently underwent repeat revascularization. In the rare, carefully selected patient, stents may represent an adjunct in the management of focal coronary artery spasm, although currently medical therapy remains the standard initial approach.     

Dynamics of heart rate variability in ischemic heart disease patients after coronary artery bypass grafting

AIM: To study dynamics of 24-hour heart rate variability (HRV) after coronary artery bypass grafting (CABG) and to elucidate relationship between HRV dynamics and clinical course of the disease. METHODS AND MATERIAL: A novel methodological approach to evaluation of HRV based on measurement of mean weighted rhythmogram variation (MWRV) was implemented.Ninety patients were studied before CABG. Then HRV was assessed in 2 weeks (61 patients), 2 (45 patients), 6 (24 patients)and 12 (33 patients) months after surgery. RESULTS: At all study points HRV was lower in CHD patients than in healthy persons. Substantial lowering of average MWRV 2 weeks after surgery was followed by return to preoperative level by the end of 2 months, leveling off until 6 months and some decline by the end of a year. Individual changes of MWRV were assessed in 29 patients in whom HRV was evaluated at 5 or 4 study points. Three types of MWRV changes were distinguished: type 1 - "normal" dynamics (9 patients) - elevation of MWRV 2, 6 and 12 months; type 2 (10 patients) - elevation of MWRV after 2 and 6 months with subsequent lowering by the end of 1 year; type 3 (10 patients) - lowering of MWRV In 2 and/or 6 months. The following relationships between MWRV changes and clinical course after surgery were observed: there were no complications among patients with type 1 MWRV dynamics; 8 of 10 type 2 patients had signs of heart failure, or blood pressure elevation, or recurrence of angina by the end of 1 year: among 10 type 3 patients 6 experienced various complications. Recurrence of angina at various intervals after CABG occurred in 5 patients and in all it was associated with MWRV decrease. CONCLUSION: Pronounced decrease of MWRV between 2 and 12 months after CABG is associated with worse clinical course and its detection should trigger additional investigation and care of a patient.     

甲亢性心脏病合并冠状动脉双支血管严重痉挛1例

通过1例甲亢合并双支冠状动脉（左前降支和右冠状动脉）严重痉挛的诊治,总结分析冠状动脉痉挛与甲亢、甲亢性心脏病的可能关系和机制,提示临床上PCI术前常规冠脉内注射硝酸甘油以解除冠状动脉痉挛,尤其是合并甲亢疾病较易发生冠状动脉痉挛的临床意义。     

Life threatening coronary artery spasm in childhood Kimura's disease

A 13 year old boy is described with hypereosinophilia associated with Kimura's disease, who showed repeated life threatening syncopal attacks during daily activities or at rest. Coronary arteriography demonstrated small aneurysms with irregular vessel walls of both coronary arteries, and the absence of organic stenotic lesions. Infusion of a minimal dose of ergonovine into the right coronary artery induced severe spasm of the vessel. Ventricular fibrillation recurred even after administration of nifedipine and isosorbide was started, but was completely inhibited by prednisolone.


Keywords: coronary vasospasm; hypereosinophilia; Kimura's disease; ventricular tachyarrhythmia