Possible role of coronary artery spasm in unexplained syncope

A Super-elderly Case of Suspected New-onset Vasospastic Angina Complicated by Myocardial Bridge

A 90-year-old man experienced chest oppressive sensation at 12:30 AM for the first time. Electrocardiography showed a newly developed inversion of the terminal T-wave in the V2-5 leads. A left coronary angiogram showed no significant atherosclerotic stenosis. A myocardial bridge was found in the mid-left anterior descending artery (LAD). Myocardial scintigraphy with 123I beta-methyl 15-para-iodophenyl 3(R,S)-methylpentadecanoic acid revealed a reduced uptake in the apical and septal areas. Based on these findings, we suspected new-onset vasospastic angina complicated by a myocardial bridge in the territory of the LAD. He remained in good condition without recurrent anginal attacks after nifedipine was started before bedtime.

Ictal chest discomfort in a patient with temporal lobe seizures and amygdala enlargement

Chest discomfort is the representative symptom of dangerous coronary artery disease (CAD), but rarely occurs in patients with seizures. We treated a 74-year-old man with right mesial temporal lobe epilepsy and amygdala enlargement, who was initially suspected of CAD and underwent repeated cardiac angiography because of recurrent episodes of paroxysmal chest discomfort starting from 68 years old. He visited an epileptologist and underwent long-term video electroencephalography monitoring (LTVEM), which confirmed right temporal seizure onset during a habitual episodes of "chest discomfort," stereotyped movement of chest rubbing with the right hand, followed by impaired conscousness. Brain magnetic resonance imaging revealed right amygdala enlargement. The present case emphasizes the importance of the wide range of symptoms, such as chest discomfort, which may associated with epielpsy and result in a delayed diagnosis. LTVEM is useful for diagnosis of epilepsy with unusual seizure semiology by recording ictal EEG changes during chest discomfort.

Coronary vasospasm-induced syncope with dynamic changes of regional wall motion abnormalities confirmed real-time: a case report

Background

Coronary vasospasm is primarily characterized by transient and reversible vasoconstriction causing myocardial ischaemia and can manifest with various clinical features, including syncope.

Case summary

A 50-year-old man presented with recurrent episodes of syncope for 3 days. The last syncope history occurred during an early morning walk, accompanied by dizziness and loss of consciousness. There was no clear history of chest pain at the time. He smoked one pack of cigarettes daily and frequently consume alcohol. Approximately 3 h after admission, echocardiography initially revealed normal systolic function; however, during the examination, the patient suddenly complained of dizziness and regional wall motion abnormalities (RWMA) of the left anterior descending artery (LAD) territory were observed. Both RWMA and dizziness spontaneously improved within a few minutes. Emergency coronary angiography (CAG) was performed to confirm vasospasm. Coronary angiography revealed mild atherosclerosis of proximal LAD. After 3 min, he complained of dizziness and vague chest discomfort, and electrocardiogram revealed ST-segment elevation. We immediately performed angiography of the left coronary artery, and CAG revealed total occlusion of the proximal LAD without any provocation. After administration of intracoronary nitroglycerine, coronary flow was restored completely and ST-segment deviation normalized along with relief in chest discomfort. The patient's symptoms have not recurred for 3 months while being on calcium channel blocker and long-acting nitrates.

Discussion

Coronary vasospasm can present as transient and dynamic myocardial ischaemia along with angina. Coronary vasospasm should always be considered in the differential diagnosis for syncope.

Young Vasospastic Angina Patients Less Than 20 Years Old

BACKGROUND

Japanese Circulation Society (JCS) guidelines do not include adolescents with coronary artery spasm.Methods and Results:We recruited 18 adolescents less than 20 years old with vasospastic angina (VSA): 11 were Japanese and 3 had chest symptoms for >12 months before admission. ST-segment elevation was observed in 11 patients and none of the 18 patients had a fixed stenosis. Spasm provocation tests were performed in 9 patients and two-thirds had multiple spasms; 6 suffered from acute myocardial infarction and ventricular fibrillation occurred in 2 patients; 1 patient died and the remaining 17 patents survived.

CONCLUSIONS

Clinical status of adolescents with VSA was as severe as in adults with refractory VSA. Cardiologists should cooperate with pediatricians to diagnose and treat adolescents with VSA. There is a need to establish the additional issues for adolescents with coronary spasm in the JCS guidelines.

Impact of pharmacological spasm provocation test in patients with a history of syncope

Coronary artery spasm is involved in the pathogenesis of various cardiac disorders. We investigated patients with a history of syncope who underwent elective coronary angiography. We retrospectively analyzed 5781 consecutive patients who had diagnostic or follow-up angiography during a 26-year period. During this period, we found 95 patients with a history of syncope before elective coronary angiography. Pharmacological spasm provocation testing was performed in 64 patients with a history of syncope (<1 year). Positive pharmacological response was observed in 48 patients, while the remaining 16 patients had negative tests. Positive spasm was defined as a transient ≥90% narrowing with ischemic electrocardiographic changes. Among the 64 patients, definite coronary spastic angina (CSA) was found in 35 patients (54.7%) and suspected CSA was found in 13 patients (20.3%). Among the 35 patients with definite CSA, 22 patients (62.9%) had chest symptoms before syncope, but 13 (37.1%) had no chest symptom before syncope. No difference in clinical characteristics was observed between the two groups. Focal spasm during pharmacological spasm provocation tests was significantly higher in patients with chest symptoms than in those without chest symptoms before syncope (54.3 vs. 12.0%, p < 0.002). CSA was observed in 75.0% of patients with a history of syncope (<1 year). Thirteen patients with definite CSA had neither chest pain nor chest pressure before syncope. We should therefore investigate coronary artery spasm as a potential etiology in patients with a history of syncope.

Life-threatening arrhythmias leading to syncope in patients with vasospastic angina

The coronary artery diseases (CAD) that can lead to the occurrence of a syncopal attack include acute coronary syndrome, vasospastic angina, effort angina, and prior myocardial infarction. The possible mechanisms considered to lead to syncope in patients with CAD are pump failure, tachyarrhythmia, bradycardia, and vagal stimulation. Coronary artery spasm, in particular, is occasionally observed in patients with unexplained syncope in Japan. Life-threatening arrhythmias are among the most serious complications of an ischemic attack caused by coronary spasm, and are associated with an increased risk of syncope and/or sudden cardiac death (SCD). Therefore, during the initial evaluation of unexplained syncope, the diagnosis of vasospastic angina (VSA) needs to be made promptly, to avert the risk of SCD as a consequence of syncope triggered by the lethal arrhythmia. The inducibility of polymorphic ventricular tachycardia or ventricular fibrillation, increased QT dispersion, T-wave alternans, and early repolarization during the asymptomatic period are considered risk markers for ventricular arrhythmias during coronary spasm. In view of the conclusions from several studies, implantable cardioverter/defibrillator therapy should be considered in patients who are at high risk for recurrence of syncope due to a fatal ventricular arrhythmia triggered by coronary spasm, despite appropriate medical therapy.

Clinical usefulness, angiographic characteristics, and safety evaluation of intracoronary acetylcholine provocation testing among 921 consecutive white patients with unobstructed coronary arteries

BACKGROUND

Coronary spasm can cause myocardial ischemia and angina in patients with and those without obstructive coronary artery disease. However, provocation tests using intracoronary acetylcholine administration are rarely performed in clinical routine in the United States and Europe. Thus, we assessed the clinical usefulness, angiographic characteristics, and safety of intracoronary acetylcholine provocation testing in white patients with unobstructed coronary arteries.

METHODS AND RESULTS

From September 2007 to June 2010, a total of 921 consecutive patients (362 men, mean age 62±12years) who underwent diagnostic angiography for suspected myocardial ischemia and were found to have unobstructed coronary arteries (no stenosis ≥50%) were enrolled. The intracoronary acetylcholine provocation testing was performed directly after angiography according to a standardized protocol. Three hundred forty-six patients (35%) reported chest pain at rest, 222 (22%) reported chest pain on exertion, 238 (24%) reported a combination of effort and resting chest pain, and 41 (4%) presented with troponin-positive acute coronary syndrome. The overall frequency of epicardial spasm (>75% diameter reduction with angina and ischemic ECG shifts) was 33.4%, and the overall frequency of microvascular spasm (angina and ischemic ECG shifts without epicardial spasm) was 24.2%. Epicardial spasm was most often diffuse and located in the distal coronary segments (P<0.01). No fatal or irreversible nonfatal complications occurred. However, 9 patients (1%) had minor complications (nonsustained ventricular tachycardia [n=1], fast paroxysmal atrial fibrillation [n=1], symptomatic bradycardia [n=6], and catheter-induced spasm [n=1]).

CONCLUSIONS

Epicardial and microvascular spasm are frequently found in white patients with unobstructed coronary arteries. Epicardial spasm is most often diffuse and located in the distal coronary segments. The intracoronary acetylcholine provocation test is a safe technique to assess coronary vasomotor function.

Low glomerular filtration rate is associated with high prevalence of vasospastic angina

BACKGROUND

Although chronic kidney disease is associated with a high prevalence of cardiovascular disease, the relationship between coronary artery spasm and renal dysfunction has not been elucidated.

METHODS AND RESULTS

We evaluated 139 patients with chest pain at rest who had no significant organic stenosis on coronary angiograms and who underwent coronary spasm provocation tests using acetylcholine or ergonovine. The results of the provocation tests revealed that 59 patients had vasospastic angina (VSA), and that 80 did not (non-VSA). We analyzed the association between VSA and renal dysfunction using the estimated glomerular filtration rate (eGFR). The eGFR was significantly lower in the VSA group than in the non-VSA group (P = 0.013). The patients were assigned to quartiles (Q) 1, 2, 3 and 4 based on eGFR (ml·min⁻¹·1.73 m²) < 64.1, 64.1-74.7, 74.8-85.0 and ≥ 85.1, respectively, in each of which the prevalence of VSA was 57%, 53%, 34% and 26%, respectively. The prevalence of VSA was significantly higher in Q1 than in Q4 (P = 0.008). Logistic regression analysis showed that the independent factors associated with the presence of VSA were a lower eGFR (P = 0.011) and male gender (P = 0.001).

CONCLUSIONS

Lower levels of eGFR in our study population were significantly and independently associated with a high prevalence of VSA, suggesting that a lower eGFR could be a risk factor for VSA.

Endocardial arrhythmogenic mechanisms of torsades de pointes in patients with the congenital long QT syndrome

We injected acetylcholine (Ach) into the coronary artery to ascertain whether coronary vasospasm contributed to the syncopal events or chest oppression suffered by 3 patients with long QT syndrome (LQTS). During the test, a quadripolar electrode catheter was placed in the right ventricle and the activation-recovery interval was reanalyzed from the stored data. Intracoronary Ach transiently prolonged the QT intervals in all 3 patients without inducing coronary vasospasm. The Ach-induced QT prolongation was associated with enhanced spatial and temporal dispersion of intra-ventricular repolarization. The electrophysiological abnormalities were consistent with the putative arrhythmogenic mechanisms identified in experimental studies of LQTS.

Relationship between serum lipoprotein(a) concentrations and coronary vasomotion in coronary spastic angina

BACKGROUND

Elevated lipoprotein(a) (Lp(a)) concentrations are reported to impair endothelium-dependent vasodilatation of the epicardial coronary artery. However, the effects on vasomotor abnormalities in coronary spastic angina (CSA) have not been thoroughly investigated.

METHODS AND RESULTS

In the present study 80 sites of spasm (spastic sites) without significant organic stenosis (% diameter stenosis <50%) were assessed in 80 patients with CSA diagnosed by intracoronary ergonovine (EM) test. Spastic sites were divided into 2 groups: Group 1 included 30 sites provoked by the full dose (=50 microg) of EM, and Group 2 included 50 sites provoked with less than 50 microg (34.7+/-8.2 microg). Control subjects (n=22) did not show coronary spasm with the EM test. Serum Lp(a) concentrations were measured in all patients. Group 2 had a significantly greater basal coronary artery tone in the spastic sites than Group 1 (p<0.001). Lp(a) level in Group 2 was significantly higher compared with both the control group and Group 1 (p<0.05 by analysis of variance). Multivariate analysis confirmed that only serum Lp(a) concentration was associated with low-dose EM spasm provocation.

CONCLUSIONS

Serum Lp(a) concentration could be a marker for high disease activity in CSA.

Acetylcholine-induced prolongation of the QT interval in idiopathic long QT syndrome

Intracoronary acetylcholine prolonged the QT interval in 5 patients with congenital long QT syndrome but not in subjects with normal QT intervals. Prolongation was not due to bradycardia or adrenergic drive, and atropine was suggested to attenuate the response.

Magnesium repletion and its effect on potassium homeostasis in critically ill adults: results of a double-blind, randomized, controlled trial

OBJECTIVES

The aims of this study were to evaluate the safety and efficacy of magnesium replacement therapy and to determine its effect on potassium retention in hypokalemic, critically ill patients.

DESIGN

A prospective, double-blind, randomized, placebo-controlled trial.

SETTING

A surgical intensive care unit (ICU).

PATIENTS

A total of 32 adult surgical ICU patients were admitted to the study on the basis of documented hypokalemia (potassium of < 3.5 mmol/L) within the 24-hr period before entering the study. Patients were randomized to receive either placebo (n = 15) or magnesium sulfate (n = 17). One patient from each group was excluded from the study due to failure to complete the full series of doses.

INTERVENTIONS

Patients received a "test dose" of either magnesium sulfate (2 g, 8 mmol) or placebo (5% dextrose in water) infused over 30 mins every 6 hrs for eight doses. The next schedule test dose was held if hypermagnesemia (magnesium of > 2.8 mg/dL [> 1.15 mmol/L]) was documented at any time during the study. Routine replacements of potassium and magnesium continued during the duration of the study, when clinically indicated, for serum potassium concentrations of 3.5 mmol/L or serum magnesium concentrations of < 1.8 mg/dL (< 0.74 mmol/L).

MEASUREMENTS AND MAIN RESULTS

Age, weight, and Acute Physiology and Chronic Health Evaluation II scores were recorded on entry into the study. Just before administration of each test dose, blood was drawn for magnesium and potassium, bicarbonate, pH, and glucose determinations, and an aliquot of the preceding 6 hrs urine collection was sent for magnesium and potassium determinations. Serum calcium, phosphate, urea nitrogen, and creatinine concentrations were measured daily. The amounts of magnesium and potassium administered via parenteral nutrition, tube feeding, and replacement infusions were calculated for each 6-hr interval. The amounts of magnesium and potassium excreted in the urine were similarly assessed. The groups showed no differences with regard to age, weight, Acute Physiology and Chronic Health Evaluation II scores, or initial serum magnesium concentration. Initial potassium, bicarbonate, pH, calcium, phosphate, glucose, blood urea nitrogen, and creatinine values were not different between groups. Patients receiving magnesium sulfate showed a statistically significant increase in serum magnesium concentration at 6 hrs when compared with placebo, as well as with itself at time 0 (p < .0001), a difference maintained throughout the study. Compared with the placebo group, the total amount of elemental magnesium administered was significantly greater in the treatment group (1603 +/- 124 vs. 752 +/- 215 mg [65.7 +/- 5.8 vs. 30.8 +/- 8.8 mmol], p < .0001), as was urine magnesium excretion (1000 +/- 156 vs. 541 +/- 68 mg [41.0 +/- 6.4 vs. 22.2 +/- 2.8 mmol] p < .0001). However, the net magnesium balance (total magnesium in - total urine magnesium) was significantly more positive in the treatment group (612 +/- 180 vs. 216 +/- 217 mg [25.1 +/- 7.4 vs. 8.9 +/- 8.9 mmol], p < .005). The treatment and control groups had the same serum potassium concentrations and did not receive different amounts of potassium (245 +/- 39 vs. 344 +/- 45 mmol, respectively, p = .06), although the treatment group required less potassium replacement/6 hrs by 30 hrs compared with itself at time 0 (p < .05). Despite the same serum potassium values, the net potassium balance for 48 hrs was positive in the treatment group (+ 72 +/- 32 mmol) and negative in the control group (-74 +/- 95 mmol, p < .05). There were no complications associated with the magnesium sulfate administration.

CONCLUSIONS

Magnesium sulfate administered according to the above regimen safety and significantly increases the circulating magnesium concentration. Despite greater urine magnesium losses in the treatment group, this group exhibited significantly better magnesium retention.

Cardiac arrest and sudden unexpected death in variant angina: complications of coronary spasm that can occur in the absence of severe organic coronary stenosis

Experiences in 81 patients with variant angina were reviewed with the goal of determining which clinical features were associated with the greatest risk of angina-linked cardiac arrest (13 patients) or sudden unexpected death (9 patients). The risk of occurrence of one of these actually or potentially fatal events was approximately tripled by the presence of either a history of angina-linked syncope or documentation of serious arrhythmia complicating attacks. An unexpected finding was that the risk was increased 1.5-fold by the absence of high-grade organic coronary stenosis. Cardiac arrest and sudden death are important risks of variant angina, which can occur without the presence of severe organic coronary stenosis. These risks can be reduced by adequate vasodilator therapy that includes a calcium channel blocker.

Effect of direct intracoronary administration of methylergonovine in patients with and without variant angina

The effects of intracoronary administration of methylergonovine were studied in 21 patients with variant angina and 22 patients with atypical chest pain and in others without angina pectoris (control group). Methylergonovine was administered continuously at a rate of 10 micrograms/min up to 50 micrograms. In all patients with variant angina, coronary spasm was provoked at a mean dose of 28 +/- 13 micrograms (mean +/- SD). In the control group neither ischemic ST change nor localized spasm occurred. The basal tone of the right coronary artery was significantly lower than that of the left coronary artery. The percentage of vasoconstriction of the right coronary artery was significantly higher than that of the left coronary artery. These results suggest that spasm provocation tests, which use an intracoronary injection of a relatively low dose of methylergonovine, have a high sensitivity in variant angina and the vasoreactivity of the right coronary artery may be greater than that of the other coronary arteries.