Severe coronary vasospasm associated with hyperthyroidism causing myocardial infarction

Acute coronary syndrome with severe atherosclerotic and hyperthyroidism: A case report

BACKGROUND

Acute coronary syndrome (ACS) encompasses a spectrum of cardiovascular emergencies arising from the obstruction of coronary artery blood flow and acute myocardial ischemia. Recent studies have revealed that thyroid function is closely related to ACS. However, only a few reports of thyrotoxicosis-induced ACS with severe atherosclerosis have been reported.

CASE SUMMARY

A 33-year-old man, who had a history of hyperthyroidism without taking any antithyroid drugs and no history of coronary heart disease, experienced neck pain with occasional heart palpitations starting 3 mo prior that were aggravated after an activity. As the symptoms worsened at 21 d prior, he went to a hospital for treatment. The electrocardiogram examination showed a multilead ST segment elevation and pathological Q waves. Based on these findings and his symptoms, the patient was diagnosed with a suspected myocardial infarction and transferred to our hospital on July 2, 2020. He was diagnosed with a rare case of ACS due to coronary artery atherosclerosis in the anterior descending artery complicated by hyperthyroidism. A paclitaxel-coated drug balloon was used for treatment to avoid the use of metal stents, thus reducing the time of antiplatelet therapy and facilitating the continued treatment of hyperthyroidism. The 9-mo follow-up showed favorable results.

CONCLUSION

This case highlights that atherosclerosis is a cause of ACS that cannot be ignored even in a patient with hyperthyroidism.

Hyperthyroidism Is Associated with the Development of Vasospastic Angina, but Not with Cardiovascular Outcomes

Vasospastic angina (VA) is a functional disease caused by the alteration of vasomotor tone. We investigated the association of hyperthyroidism with the development and prognosis of VA. Study data were obtained from a prospective multicenter registry that included patients who had symptoms suggestive of VA. Coronary angiography and an ergonovine provocation test were performed, and patients were classified into a VA and a non-VA group. Among 1239 patients with suspected VA, 831 patients were classified in the VA group. Hyperthyroidism was more common in the VA group than in the non-VA group (10.0% vs. 3.7%, p < 0.001). After adjusting for confounding factors, hyperthyroidism was independently associated with a 3.27-fold increased risk of VA. Especially in women, hyperthyroidism was associated with a 4.38-fold higher risk of VA. All-cause death rates did not differ according to the presence or absence of hyperthyroidism. Hyperthyroidism is independently associated with the occurrence of VA especially in women but did not affect the total death in VA patients. Clinicians need to be aware of the role of thyroid function in patients with suspected VA.

Comparison of myocardial deformation indices during rest and after activity in untreated hyperthyroid patients with normal population

BACKGROUND

Thyroid hormones play an essential role on the cardiovascular system. Also, thyroid diseases have a prominent adverse effect on myocardial and vascular functions. Therefore, the aim of this study was to compare myocardial deformation indices during resting and after activity between the untreated hyperthyroid patients and normal population.

METHODS

We included 26 untreated participants who were newly diagnosed with hyperthyroidism and 26 healthy participants matched in terms of age and sex. The left ventricular end-diastolic volume index (LVEDVI), Heart Rate (HR), Cardiac Output (CO), systolic and diastolic blood pressures, Global Longitudinal Strain (GLS), Global Circumferential Strain (GCS), Rate-Pressure Product (RPP), systolic and diastolic strains rates were measured in rest and peak of exercise in stress echocardiography.

RESULTS

Age and sex distributions were similar among the groups. Also, mean serum TSH was 0.08 ± 0.08 ng/dL in the case group. The participants with the untreated hyperthyroidism had lower Ejection Fraction change (ΔEF), GLS, peak stress systolic and diastolic strains rates compared to the control group. Also, there was a positive association between TSH levels and basal HR, RPP, CO, as well as a negative correlation with basal and maximum GLS, ΔHR, ΔEF, and ΔCO. Also, a duration of symptoms had a linear association with rest HR, CO, and LVEDVI, as well as a negative correlation with rest and maximal GLS, ΔHR, and ΔGLS.

CONCLUSION

Myocardial deformation assessed by 2DE imaging are significantly impaired in the hyperthyroid patients. In this regard, further studies with a larger sample size are required to confirm the results of this study.

Manifestation of non-ST elevation myocardial infarction due to hyperthyroidism in an anomalous right coronary artery

Introduction

Anomalous origin of the right coronary artery (RCA) from the left coronary cusp of the aorta is a moderately rare but potentially life-threatening incident. Myocardial infarction (MI) and sudden cardiac death have been described with this anomaly, especially in those who engage in excessive exercise. However, this case study shows this incidence in association with hyperthyroidism.

Case description

A previously healthy 51-year-old female with history of hypothyroidism presented with acute onset chest pain for 1 day. Patient's electrocardiogram was normal, however, she had elevated troponins and given her typical chest pain, she was diagnosed with acute coronary syndrome (ACS). The patient had been on levothyroxine and was found to have a subnormal thyroid-stimulating hormone level suggesting hyperthyroidism. Echocardiogram was normal. Coronary angiogram showed an anomalous RCA arising from the left coronary cusp of the sinus of Valsalva and no evidence of atherosclerosis. A coronary computed tomography angiogram was done confirming this finding and showed a slit-like deformity of the coronary ostium with at least 50% luminal stenosis. The patient was referred to a cardiothoracic surgeon for potential coronary artery bypass graft.

Discussion

This case illustrates a rare presentation of ACS due to hyperthyroidism in an anomalous RCA. MI is a rare manifestation of hyperthyroidism, but in combination with an anatomical defect, it can potentiate adverse outcomes. The mechanisms by which thyroid hormones influence cardiovascular hemodynamics are by causing a hyperdynamic circulatory state, increasing myocardial oxygen demand, and increasing the risk of coronary vasospasm. The combination of anatomic and metabolic defects is what likely precipitated this patient's outcome.

Severe Cerebral Vasospasm in Patients with Hyperthyroidism

Cerebral vasospasm associated with hyperthyroidism has not been reported to cause cerebral infarction. The case reported here is therefore the first of cerebral infarction co-existing with severe vasospasm and hyperthyroidism. A 30-year-old woman was transferred to our hospital in a stuporous state with right hemiparesis. At first, she complained of headache and dizziness. However, she had no neurological deficits or radiological abnormalities. She was diagnosed with hyperthyroidism 2 months ago, but she had discontinued the antithyroid medication herself three days ago. Magnetic resonance imaging and angiography showed cerebral infarction with severe vasospasm. Thus, chemical angioplasty using verapamil was performed two times, and antithyroid medication was administered. Follow-up angiography performed at 6 weeks demonstrated complete recovery of the vasospasm. At the 2-year clinical follow-up, she was alert with mild weakness and cortical blindness. Hyperthyroidism may influence cerebral vascular hemodynamics. Therefore, a sudden increase in the thyroid hormone levels in the clinical setting should be avoided to prevent cerebrovascular accidents. When neurological deterioration is noticed without primary cerebral parenchyma lesions, evaluation of thyroid function may be required before the symptoms occur.

A rare case of gestational thyrotoxicosis as a cause of acute myocardial infarction

Angina pectoris in pregnancy is unusual and Prinzmetal's angina is much rarer. It accounts for 2% of all cases of angina. It is caused by vasospasm, but the mechanism of spasm is unknown but has been linked with hyperthyroidism in some studies. Patients with thyrotoxicosis-induced acute myocardial infarction are unusual and almost all reported cases have been associated with Graves' disease. Human chorionic gonadotropin hormone-induced hyperthyroidism occurs in about 1.4% of pregnant women, mostly when hCG levels are above 70-80 000 IU/L. Gestational transient thyrotoxicosis is transient and generally resolves spontaneously in the latter half of pregnancy, and specific antithyroid treatment is not required. Treatment with calcium channel blockers or nitrates reduces spasm in most of these patients. Overall, the prognosis for hyperthyroidism-associated coronary vasospasm is good. We describe a very rare case of an acute myocardial infarction in a 27-year-old female, at 9 weeks of gestation due to right coronary artery spasm secondary to gestational hyperthyroidism with free thyroxine of 7.7 ng/dL and TSH <0.07 IU/L.

LEARNING POINTS

AMI and cardiac arrest due to GTT despite optimal medical therapy is extremely rare.Gestational hyperthyroidism should be considered in pregnant patients presenting with ACS-like symptoms especially in the setting of hyperemesis gravidarum.Our case highlights the need for increased awareness of general medical community that GTT can lead to significant cardiac events. Novel methods of controlling GTT as well as medical interventions like ICD need further study.

Severe Hyperthyroidism Presenting with Acute ST Segment Elevation Myocardial Infarction

Introduction. Acute myocardial infarction is life-threatening. A cardiac troponin rise accompanied by typical symptoms, ST elevation or depression is diagnostic of acute myocardial infarction. Here, we report an unusual case of a female who was admitted with chest pain. However, she did not present with a typical profile of an acute myocardial infarction patient. Case Presentation. A 66-year-old Han nationality female presented with chest pain. The electrocardiogram (ECG) revealed arched ST segment elevations and troponin was elevated. However, the coronary angiography showed a normal coronary arterial system. Thyroid function tests showed that this patient had severe hyperthyroidism. Conclusion. Our case highlights the possibility that hyperthyroidism may cause a large area of myocardium injury and ECG ST segment elevation. We suggest routine thyroid function testing in patients with chest pain.

Takotsubo cardiomyopathy and transient thyrotoxicosis during combination therapy with interferon-alpha and ribavirin for chronic hepatitis C

BACKGROUND

Thyroid dysfunction is a common complication of chronic hepatitis C (CHC) and its therapy. Takotsubo cardiomyopathy (TCM) is a multifactorial, stress related cardiomyopathy, rarely reported in association with thyrotoxicosis. Simultaneous occurrence of TCM and thyrotoxicosis due to hepatitis C and its treatment has never been reported.

CASE PRESENTATION

A 47-year-old woman was admitted for acute chest pain, dyspnea, palpitations and diaphoresis. She had been diagnosed with CHC and had undergone 7 months of IFNα and Ribavirin therapy. At admission electrocardiogram (ECG) showed ST segment elevation, negative T waves and troponin was elevated suggesting ST segment elevation myocardial infarction (STEMI). Echocardiography demonstrated left ventricular apical akinesia and ballooning, with a left ventricular ejection fraction (LVEF) of 35%. Contrast angiography showed normal epicardial coronaries, yet a ventriculogram revealed left ventricular apical ballooning, consistent with TCM. Cardiac MRI showed left ventricle apical ballooning and no late enhancement suggesting the absence of any edema, scar or fibrosis in the left myocardium. She was diagnosed with non-autoimmune destructive thyroiditis: TSH=0.001 mU/L, free T4=2.41 ng/dl, total T3=199 ng/dl and negative thyroid antibodies. The thyroid ultrasonography showed a diffuse small goiter, no nodules and normal vascularization of the parenchyma. Following supportive treatment she experienced a complete recovery after a few weeks and she successfully completed her antiviral treatment, with no thyroid or cardiovascular dysfunction ever since. In patients treated with IFNα for CHC, the prevalence of thyroid dysfunction varies between 2.5-45.3% of cases. TCM is a stress related cardiomyopathy characterized by elevated cardiac enzymes, normal coronary angiography and an acute, transient, left ventricular apical dysfunction that mimics myocardial infarction. Most of the patients survive the initial acute event, typically recover normal ventricular function within one to four weeks and have a favorable outcome, as was the case with our patient. Thyrotoxicosis induced stress cardiomyopathy is rare and has been mostly reported in association with Graves' disease, thyroid storm, thyrotoxicosis factitia or following radioiodine therapy for toxic multinodular goiter.

CONCLUSION

Routine thyroid screening should be done in patients receiving IFN-alpha and Ribavirin for CHC and thyrotoxicosis should be considered as a possible and treatable underlying cause of TCM.

Takotsubo cardiomyopathy in a patient with multiple autoimmune disorders and hyperthyroidism

Takotsubo cardiomypathy is a very rare cardiovascular syndrome leading to myocardial infarction and left ventricular dysfunction in the absence of a detectable coronary artery lesion. It is accepted as reversible left ventricular asynergy occuring typically after an intrinsic adrenergic hyperstimulation. In this report we present Takotsubo cardiomyopathy in a 75-year-old patient with multiple autoimmune disorders.

Amiodarone-induced destructive thyroiditis associated with coronary artery vasospasm and recurrent ventricular fibrillation

A 55-year-old male on long-term amiodarone therapy presented with ischaemic chest pain and recurrent unwitnessed syncope. Interrogation of his internal cardiac defibrillator, which had been inserted 4 years earlier, revealed two episodes of ventricular fibrillation, the timing of which corresponded to his syncopal events. Severe spontaneous coronary artery vasospasm was observed on coronary angiogram. Thyroid function testing revealed severe hyperthyroidism with a diagnosis of type 2 amiodarone-induced thyrotoxicosis (AIT) subsequently made. Treatment with prednisolone therapy was commenced and thyroid function rapidly normalized. Prednisolone was weaned without recurrence of hyperthyroidism and on last review, 6 months after initial presentation, he remains free from further chest pain and arrhythmias. Our patient's presentation is a very rare case of AIT-associated coronary artery spasm and documented ischaemic ventricular fibrillation with fortunate survival.

Thyrotoxicosis-induced acute myocardial infarction due to painless thyroiditis

BACKGROUND

Thyrotoxicosis influences cardiovascular hemodynamics and can induce coronary vasospasm. Patients with thyrotoxicosis-induced acute myocardial infarction (AMI) are unusual and almost all reported cases have been associated with Graves' disease. Patients with painless thyroiditis show a thyrotoxic phase during the early stages. Here we describe a very rare case of thyrotoxicosis with painless thyroiditis-induced AMI.

SUMMARY

A 35-year-old Korean man visited the emergency room for a 2-hour duration of typical AMI chest pain. The patient did not have any coronary artery disease (CAD) risk factors. The electrocardiogram showed 3 mm of ST-segment elevation in leads II, III, and aVF, which is consistent with inferior AMI. We immediately treated the patient with aspirin, clopidogrel, and nitroglycerine and performed emergent coronary angiography. Coronary angiography showed normal coronary arteries without any stenotic lesions. Consistent with AMI, cardiac enzyme levels of serum creatine kinase (CK), CK-MB, and troponin-I were also elevated. Laboratory findings showed thyrotoxicosis without any thyroid autoantibodies. A 99m-technetium scintigraphy showed markedly decreased thyroid uptake compatible with thyroiditis. We treated the patient with calcium channel blockers and nitrates. The patient spontaneously recovered normal thyroid function after 6 weeks of observation and did not complain of chest pain.

CONCLUSION

Thyrotoxicosis due to painless thyroiditis provoked AMI in a young man who had no atherosclerotic coronary lesions and no CAD risk factors.

Takotsubo cardiomyopathy "variations on a theme"

Takotsubo Cardiomyopathy (TTC) is a fairly new diagnosis in the cardiologist's repertoire. It can present itself in multiple different forms. We describe three cases of TTC with different etiologies illustrating the broad spectrum of presentations.

Thyrotoxicosis and Coronary Artery Spasm: Case Report and Review of the Literature

A 51-year old Middle-Eastern man presented with recurrent chest pain associated with ST-segment elevation. The patient was treated with placement of a stent in the right coronary artery. He was subsequently diagnosed with severe hyperthyroidism secondary to Graves disease, which is thought to be the cause of the coronary spasm. The patient was treated with neomercazole and potassium iodide solution, and diltiazem, and nitrates with resolution of his symptoms. This unusual case highlights the importance of considering hyperthyroidism in the differential diagnosis of recurrent chest pain and coronary artery spasm. We suggest routine thyroid function testing in patients with coronary spasm.

Myocardial stunning in hyperthyroidism

The cases of two patients with hyperthyroidism and acute left ventricular (LV) dysfunction with segmental wall motion abnormalities resulting in heart failure are reported. Both had electrocardiographic changes mimicking ischemic coronary artery disease. Treatment with antithyroid medications, beta blockers, and angiotensin-converting enzyme inhibitors rapidly restored LV function. The rapid reversibility suggests a role for myocardial stunning, an important entity to recognize in hyperthyroidism since this form of LV dysfunction can be reversed with appropriate treatment.

Hyperthyroidism-associated coronary vasospasm with myocardial infarction and subsequent euthyroid angina

A 40-year-old African-American woman presented with atypical chest pain, an acute non-ST segment elevation myocardial infarction, and angiographic evidence for severe ostial vasospasm of the left main and right coronary arteries. Subsequently, she was diagnosed with hyperthyroidism and treated with antithyroid therapy and oral nitrates. Repeat angiography revealed resolution of the vasospasm; however, the chest pain recurred in the euthyroid state. Hyperthyroidism-associated coronary vasospasm is a rare disorder that characteristically causes angina in young Asian women and resolves with correction of hyperthyroidism. We present an atypical case of an African-American woman presenting with a myocardial infarction who developed recurrent angina while euthyroid.

A unique case of reversible myocardial ischemia in a hyperthyroid neonate

A case of an 8-day-old preterm neonate with heart failure, pulmonary hypertension, and myocardial ischemia due to hyperthyroidism is reported. Treatment of the disease initially with b-blockers and, upon establishment of hyperthyroidism, with propylthiouracil reversed all cardiac abnormalities. Contrary to the rule, diagnosis of hyperthyroidism in the mother was established following the diagnosis of the condition in her baby. On long-term follow-up (10 years), the child has developed normally, remains euthyroid with normal electrocardiogram. To our knowledge, diagnosis and reversal of the above-mentioned ischemic abnormalities have not been previously reported in neonates.

Thyrotoxicosis with coronary spasm that required coronary artery bypass surgery

We describe a 47-year-old woman with severe coronary vasospasm induced by hyperthyroidism. The patient complained of anginal chest pain without specific characteristics of thyrotoxicosis. Coronary arteriography was performed and revealed 90% stenosis of both the left and right coronary os. She was treated with emergent coronary artery bypass graft surgery. Postoperatively, she exhibited a comatose mentality. Severe thyrotoxicosis was indicated on thyroid function tests and thyrotoxic storm was diagnosed. Nineteen days after the surgery and following the initiation of propylthiouracil treatment, coronary arteriography revealed entirely normal coronary arteries.

Bilateral extensive cerebral infarction and mesenteric ischemia associated with segmental arterial mediolysis in two young women

Segmental arterial mediolysis (SAM) is a rare non-atherosclerotic non-inflammatory vascular disease that affects mainly muscular arteries of the splanchnic and cerebral territories. Reported herein are two cases of SAM in young women with fatal outcome. One of the patients had an atypical form of the disease, which primarily affected small intestinal submucosal and subserosal arteries, and resulted in acute mesenteric ischemia. The other had bilateral brain infarction with SAM of internal carotid arteries (ICA). Pathological examination of both cases did not reveal the cause of blood flow disturbance: large mesenteric branches of the former and ICA of the latter were free of either dissection or thrombosis; in addition, small intestinal arteries of the first patient did not show signs of vasculitis. These findings suggest that unusual pathways of arterial occlusion and dissection may occur in the context of SAM.

Improvement of cerebral arterial stenosis associated with Basedow's disease. Case report

A 29-year-old female presented with Basedow's disease manifesting as sudden vomiting, diarrhea, fever over 38 degrees C, transient aphasia, and numbness in her extremities. These symptoms were considered due to cerebral ischemia at a local clinic. Magnetic resonance angiography indicated stenosis of the bilateral distal internal carotid arteries and the bilateral proximal anterior cerebral and middle cerebral arteries. Thyroid swelling and exophthalmos were observed. She was transferred to our hospital. Endocrine function tests showed hyperthyroidism. The diagnosis was Basedow's disease. Her symptoms disappeared after receiving intravenous drip infusion of fluid replacement, and antithyroid and antiplatelet medication. After she became euthyroid, cerebral angiography and magnetic resonance angiography revealed improvement of the stenosis of the cerebral arteries. Stenosis of the terminal portion of the internal carotid artery associated with Basedow's disease is extremely rare. Conservative treatment mainly including antithyroid medications for Basedow's disease, and antiplatelet drugs and intravenous replacement fluid for the ischemic manifestations should be the first choice of treatment unless immediate vascular reconstruction is necessary.

Severe coronary artery spasm can be associated with hyperthyroidism

BACKGROUND

Coronary artery spasm is not infrequently seen in Korea. Most of the patients with coronary spasm show a focal spasm in coronary angiography. However, the cause of the disease is not well known. There have been a few anecdotal case reports of coronary artery spasm associated with hyperthyroidism, but there has not been a report concerning a large series of such patients. Over a period of 5 years and 8 months, we experienced eight patients having the diffuse or severe type of coronary artery spasm in association with hyperthyroidism.

METHODS

We investigated the characteristics of the patients with coronary artery spasm, which was diagnosed by coronary angiography or by provocation with an intracoronary injection of acetylcholine or ergonovine. The demographic data, coronary angiographic findings, thyroid function test results, and the follow-up clinical data of the eight patients having coronary artery spasm associated with hyperthyroidism were analyzed.

RESULTS

All eight patients had Graves' disease. In six patients, the coronary arterial vasoconstriction developed during the coronary angiography without an injection of ergonovine. In three patients, the left main stem coronary artery was involved in the spasm. Among these eight patients, five were female, and all of these female patients were < or = 51 years old. All of the patients were treated with anti-thyroid medications, calcium channel blockers, and long-acting nitroglycerines; they all remained free of chest pain during the median follow-up period of 5 years.

CONCLUSIONS

A severe form of coronary artery spasm could be associated with hyperthyroidism. A high level of suspicion and the thyroid function study should be mandatory for patients with coronary artery spasm, especially for the young female patients.

Unstable angina with normal coronary angiography in hyperthyroidism: a case report

Hyperthyroidism is associated with an increase in myocardial oxygen consumption that, due to an imbalance of oxygen demand and supply, can cause angina. However, subclinical hyperthyroidism rarely presents as chest pain in the resting state. Herein, we present a case of subclinical hyperthyroidism involving a 58-year-old male who complained of frequent chest tightness and typical electrocardiographic changes while in a resting state. Coronary angiography showed no significant lesion. Laboratory data showed that the patient suffered from hyperthyroidism, for which he was successfully treated with anti-thyroid agents. We are reminded that typical chest pain might be the first symptom of hyperthyroidism.

Molecular classification and pathogenesis of eosinophilic disorders: 2005 update

Use of the term "idiopathic hypereosinophilic syndrome (HES)" has highlighted our basic lack of understanding of the molecular pathophysiology of eosinophilic disorders. However, over the last 10 years, the study of hypereosinophilia has enjoyed a revival. This interest has been rekindled by two factors: (1) the development of increasingly sophisticated molecular biology techniques that have unmasked recurrent genetic abnormalities linked to eosinophilia, and (2) the successful application of targeted therapy with agents such as imatinib to treat eosinophilic diseases. To date, most of these recurrent molecular abnormalities have resulted in constitutively activated fusion tyrosine kinases whose phenotypic consequence is an eosinophilia-associated myeloid disorder. Most notable among these are rearrangements of platelet-derived growth factor receptors alpha and beta (PDGFRalpha, PDGFRbeta), which define a small subset of patients with eosinophilic chronic myeloproliferative disorders (MPDs) and/or overlap myelodysplastic syndrome/MPD syndromes, including chronic myelomonocytic leukemia. Discovery of the cryptic FIP1L1-PDGFRA gene fusion in cytogenetically normal patients with systemic mast cell disease with eosinophilia or idiopathic HES has redefined these diseases as clonal eosinophilias. A growing list of fibroblast growth factor receptor 1 fusion partners has similarly emerged in the 8p11 myeloproliferative syndromes, which are often characterized by elevated eosinophil counts. Herein the focus is on the molecular gains made in these MPD-type eosinophilias, and the classification and clinicopathological issues related to hypereosinophilic syndromes, including the lymphocyte variant. Success in establishing the molecular basis of a group of once seemingly heterogeneous diseases has now the laid the foundation for establishing a semi-molecular classification scheme of eosinophilic disorders.

Reversible left ventricular dysfunction "takotsubo" cardiomyopathy associated with hyperthyroidism

Myocardial stunning with hyperthyroidism is rare. A 79-year old woman with hyperthyroidism was admitted to our hospital complaining of palpitations due to paroxysmal atrial fibrillation. An echocardiogram showed akinesis of the apical wall which was not observed 2 weeks before admission. Cardiac catheterization performed in the acute phase showed normal coronary arteries and no evidence of provocative spasms. The wall motion abnormality disappeared entirely after 1 week in hospital. We report a case of transient left ventricular dysfunction, so called "takotsubo" cardiomyopathy, associated with hyperthyroidism.

Cardiac Wall Motion Abnormalities Observed in a Patient With Transient Hyperthyroidism

A 74-year-old woman, with a history of hypertension and hyperlipidemia, was admitted to our hospital. She was found to have a sinus tachycardia with ST-segment elevations in leads II, III, (a)V(F), and V(3) through V(6) in electrocardiography, hypokinesis of the left ventricular apex by echocardiography, and normal findings on coronary angiography. Blood analysis revealed an increase in the creatine kinase MB fraction, a significant positive detection in troponin T, and transient elevations in the concentrations of free triiodothyronine, free thyroxine, thyroid globulin antibody, and thyroid peroxidase antibody. Defects in myocardial perfusion and fatty acid metabolism in the apical area were also demonstrated by myocardial scintigraphy. These data suggest that tako-tsubo syndrome or myocardial infarction may be induced in patients with mild and transient hyperthyroidism.

Isolated coronary ostial stenosis associated with coronary vasospasm

A 50-year-old woman was brought to the emergency room in a preshock condition. An emergency coronary angiogram revealed 90% ostial stenosis of the left coronary artery with delayed distal filling. After intracoronary nitrate, the degree of stenosis was reduced to 75%; no other coronary lesions were evident. The patient was found to have hyperthyroidism and she became euthyroid after a 2-month regimen of methimazole. A follow-up coronary angiogram showed that the left coronary artery had 50% ostial stenosis without delayed distal filling. At the same time, an aortogram showed complete occlusion of the right subclavian artery in its proximal site, a slight dilatation of the truncus brachiocephalic artery, and a diffuse wall irregularity of the abdominal aorta, suggestive of Takayasu's arteritis.