Unobstructed Coronary Arteries Research Articles

The role of delayed contrast-enhanced cardiac magnetic resonance in differentiating myocarditis from myocardial infarction

A number of different conditions can present with symptoms that mimics acute coronary syndrome (ACS). Even after performing coronary angiography, diagnosis can still be challenging. The aim of this study was to evaluate the utility of contrast-enhanced cardiac magnetic resonance (CMR) to differentiate between myocarditis and myocardial infarction (MI) in patients presenting with acute chest pain syndrome, elevated cardiac markers, and unobstructed coronary arteries. We studied 26 consecutive patients (mean age 32.4+ 11.3 years, 80.1% males) presenting with acute symptoms, elevated cardiac markers, unobstructed coronary arteries, and referred for Gadolinium-enhanced CMR examinations. Myocarditis was ascertained by the presence of myocardial edema and/or epicardial or scattered intra-myocardial late gadolinium enhancement (LGE). Myocardial infarction was diagnosed if there was territorial subendocardial LGE with variable degrees of transmural involvement. In patients with no LGE, the diagnosis was uncertain. Of 26 patients, 15 (57.7%) were initially diagnosed with ACS, the majority (8 patients, 53.3%) had LGE pattern of myocarditis, 4 (26.7%) had LGE pattern of MI. The remaining 11 patients had suspected myocarditis, 2 (18.2%) had LGE pattern of MI, and 7 (63.6%) had LGE pattern of myocarditis. Five (19.2%) patients had no LGE and diagnosis was unclear. Cardiac magnetic resonance helped to reclassify more than half of our patients (57.7%). We demonstrated that contrast-enhanced CMR allows differentiation between MI and myocarditis in patients presenting with possible ACS and unobstructed coronary arteries. This, in turn, helps with planning long-term therapeutic strategies and redefines the patient’s future risk.

The role of cardiovascular magnetic resonance imaging in patient with myocardial infarction and unobstructed coronary arteries

UvOd: Infarkt miokarda bez opstruktivne koronarne bolesti srca (KBS) heterogeni je poremecaj s razlicitim mehanizmom nastanka te je najcesce uzrokovan rupturom plaka. Može se javiti i kod bolesnika bez rupture plaka i tada je uzrokovan vazospazmom, embolizmom, disekcijom ili okluzijom ogranka. Magnetna rezonancija srca jedna je od najtocnijih neinvazivnih slikovnih metoda u procjeni ireverzibilnog ostecenja miokarda.

Evidence of myocardial scarring and microvascular obstruction on cardiac magnetic resonance imaging in a series of patients presenting with myocardial infarction without obstructed coronary arteries.

Patients with acute chest pain, electrocardiographic ST-elevation and significant elevation of cardiac troponin but without obstructive coronary artery disease represent a diagnostic and therapeutic dilemma. Cardiac magnetic resonance imaging (CMR) can elucidate underlying alternative causes of troponin elevation including detection of (minor) myocardial infarction (MI) by identifying myocardial scarring as delayed enhancement. Of 77 patients, who were admitted between March 2009 and December 2012 with electrocardiographic (ECG) and biochemical evidence of acute MI without obstructive coronary artery disease, 45 patients underwent CMR that showed in 11/77 (14%) late gadolinium enhancement (LGE), compatible with myocardial scarring. We analyzed clinical, echocardiographic, and CMR data of these patients. Elevated troponin I levels were observed in all patients (median 1.3 ng/l, IQR 0.44-187) with median peak creatinine phosphokinase of 485 U/l (IQR 234-618). Echocardiographic wall motion abnormalities were detected in 8/11 (73%) patients; in 75% of these segments, ECG abnormalities were observed in corresponding leads. CMR detected LGE in the inferior (4/11), the inferolateral (5/11), the inferoseptal (2/11), the anterior (3/11), apical (3/11) and in the lateral segments (2/11). In addition, in all but two patients, these segments matched ECG abnormalities in corresponding leads. CMR identified microvascular obstruction in 4/11 (36%) patients. Patients with clinical, ECG, and biochemical signs of acute MI but unobstructed coronary arteries may have CMR-detectable myocardial scars. Information on myocardial scarring may help to make the diagnosis and draw therapeutic consequences. This case series underlines the value of contrast-enhanced CMR for myocardial tissue characterization.

Coronary Microvascular Dysfunction Assessed by Intracoronary Acetylcholine Provocation Testing Is a Frequent Cause of Ischemia and Angina in Patients With Exercise‐Induced Electrocardiographic Changes and Unobstructed Coronary Arteries

The exercise electrocardiogram (ECG) is a standard examination in patients with suspected coronary artery disease. However, despite a pathologic result, many patients undergoing diagnostic coronary angiography do not have any significant epicardial stenosis. In this study, we assessed the relation between a pathologic exercise ECG and coronary microvascular dysfunction in response to intracoronary acetylcholine (ACh) provocation in patients without any relevant epicardial stenosis. Coronary microvascular dysfunction is significantly more often in patients with angina, unobstructed coronary arteries and a pathologic exercise stress test compared to those without pathologic stress test. This study recruited 137 consecutive patients with exertional angina pectoris who underwent diagnostic coronary angiography between September 2008 and April 2011 (68% women; mean age, 63 ± 10 years). In none of the patients was there a stenosis of >50%. All patients underwent an exercise ECG before angiography and intracoronary ACh provocation testing for assessment of coronary vasomotor responses directly after angiography. The exercise ECG showed an abnormal result in 69 patients (50%; ST-segment depression ≥0.1 mV and/or reproduction of the patient's usual symptoms). The ACh test revealed a coronary vasomotor abnormality (reproduction of the patient's symptoms, ischemic ECG shifts ± diffuse distal vasoconstriction) in 87 patients (64%). Such a result was significantly more often found in patients with a pathologic exercise ECG (50/69 [72%] vs 19/69 [28%], P = 0.034). There were no other statistically significant differences between patients with and those without pathologic exercise ECG. Coronary microvascular dysfunction is frequently found in patients with exertional angina pectoris and unobstructed coronary arteries. Such a finding is found significantly more often in presence of a pathologic exercise ECG.

Clinical Usefulness, Angiographic Characteristics, and Safety Evaluation of Intracoronary Acetylcholine Provocation Testing Among 921 Consecutive White Patients With Unobstructed Coronary Arteries

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. 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]). 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.

A Case of Urgent PCI after Diagnosis of Acute Coronary Syndrome in a Japanese Man with Unobstructed Coronary Arteries during Posted Overseas in Southeast Asia

A Case of Urgent PCI after Diagnosis of Acute Coronary Syndrome in a Japanese Man with Unobstructed Coronary Arteries during Posted Overseas in Southeast Asia

Severe Hypokalemia Probably Associated With Sertraline Use

To report a case of ventricular fibrillation caused by severe hypokalemia probably associated with sertraline use. A 48-year-old male patient experienced ventricular fibrillation and cardiac arrest 2 hours after an uneventful coronary angiography procedure, which revealed normal, unobstructed coronary arteries. Blood chemistry was immediately obtained, revealing a very low potassium (K+) level of 2.44 mEq/L. Other blood electrolytes, including magnesium, ECG, and corrected QT intervals, were all within normal limits. A thorough search for an etiology of hypokalemia, including adrenal gland causes, herbal product consumption, and toxic exposure, did not reveal any identifiable cause. This led us to consider the only drug he was on--sertraline 50 mg per day--as the possible culprit. There has been no clear identification of severe hypokalemia associated with sertraline use in the literature. However, there have been a considerable number of self-reported cases of hypokalemia in patients on sertraline therapy. Scoring according to the Naranjo adverse drug reaction scale revealed a probable relationship between severe hypokalemia and sertraline use in our patient. No clear pathogenic mechanism for the effect of sertraline on serum K equilibrium is known. However, considering the number of self-reported incidences and this case report, the effect of sertraline on serum K levels warrants consideration. This is the first documented case report of severe hypokalemia probably associated with sertraline use.

Ventricular tachycardia in hypertrophic cardiomyopathy with apical aneurysm successfully treated with left ventricular aneurysmectomy and cryoablation

A 64-year-old woman with type II diabetes mellitus was admitted to our institution with incessant ventricular tachycardia. She reverted to sinus rhythm after treatment with intravenous amiodarone, but the tachyarrhythmia recurred days later. Coronary angiography showed unobstructed coronary arteries. Left ventriculography ( Panel A , Supplementary material online, Video S1 ) revealed apical ballooning with mid-ventricular obstruction, suggestive of either large left ventricular (LV) apical aneurysm or stress (Takotsubo) cardiomyopathy. Transthoracic …

Factors affecting myocardial blood flow in patients with chest pain and unobstructed coronary arteries

Purpose: Patients with chest pain and unobstructed coronary arteries have an increased adverse cardiovascular outcome compared to those with normal coronary arteries. The aetiology is unclear but may be due to coronary microvascular dysfunction. In the largest study to date, we studied the relationship between risk factors (RF) for coronary disease (CD) and myocardial blood flow (MBF) in patients with chest pain and unobstructed coronary arteries. Methods: We recruited patients with chest pain and low or intermediate probability for CD, to undergo CT coronary angiography (CTCA). Those with either mild stenosis on CTCA or, moderate stenosis and normal functional imaging, had myocardial contrast echocardiography (MCE) at rest and during dipyridamole stress. MBF baseline (MBFb), stress (MBFs) and MBF reserve (MBFR) was obtained. High-sensitivity CRP (hs-CRP), arterial stiffness index (ASI) and carotid intima-media thickness (IMT) were measured. Results: 205 patients, mean age of 60±9.7 (range 32 – 81) years and 108 (53%) male were studied. Multiple regression analysis demonstrated the following to be significant independent predictors of reduction in MBF. Specifically, for each decade increase in age there was a 14% (p 6 RF. Between groups comparison indicated increasing RF was cumulatively associated with a reduction in MBFb: group A 32.5±7.0 dB2/s, group B 29.5±7.2 dB2/s, group C 26.6±6.0 dB2/s (p<0.01), and also MBFs: group A 69.8±13.7 dB2/s, group B 59.2±15.7 dB2/s, group C 52.0±14.7 dB2/s (p<0.001). There was no significant relationship with MBFR (group A 2.3±0.4, group B 2.2±0.5, group C 2.1±0.5). Conclusion: In patients with chest pain and unobstructed coronary arteries, MBF is significantly affected by risk factors for CAD. This effect is more pronounced as the number of risk factors increase.

Coronary microvascular dysfunction - a frequent cause for a pathologic exercise ECG in patients with unobstructed coronary arteries

Coronary microvascular dysfunction - a frequent cause for a pathologic exercise ECG in patients with unobstructed coronary arteries

Double jeopardy

Torsades de pointes ("twisting of points") (TdP) is a broad complex tachyarrhythmia which was first described in 1966 by Francois Dessertenne and usually results from prolongation of the QT interval.(1) A wide variety of drugs have been shown to prolong the QT interval in susceptible individuals.(2) We present the case of a former intravenous heroin user presenting with several episodes of TdP which were caused by QT prolongation due to methadone treatment and exacerbated by hepatitis B/C infection. Despite aggressive medical treatment and withdrawal of methadone, he had recurrent episodes of TdP which required continuous temporary cardiac pacing for six days. He was found to have moderate LV dysfunction on his echocardiogram and unobstructed coronary arteries on coronary angiography. He underwent implantation of a defibrillator due to concerns about further episodes of ventricular arrhythmias which could recur even in the absence of further methadone use.

086 THE DETECTION OF ACUTE MYOCARDITIS USING CARDIOVASCULAR MRI: A CLINICAL STUDY COMPARING T1-MAPPING, T2-WEIGHTED AND LATE GADOLINIUM ENHANCEMENT IMAGING

BackgroundThe accurate diagnosis of acute myocarditis on cardiovascular MRI (CMR) often requires multiple modalities, including T2-weighted (T2W), early and late gadolinium imaging. Novel CMR techniques are now available, including bright-blood...

Diagnostic value of cardiac magnetic resonance in patients presenting with chest pain, troponin elevation and unobstructed coronary arteries

Diagnostic value of cardiac magnetic resonance in patients presenting with chest pain, troponin elevation and unobstructed coronary arteries

Patterns of coronary vasomotor responses to intracoronary acetylcholine provocation

Since the inaugural description in 1959 by Prinzmetal,1 coronary artery spasm and abnormal coronary artery vasomotion have been extensively studied both clinically and scientifically. There is no doubt that abnormal...

Gender aspects in patients with angina and unobstructed coronary arteries

A substantial proportion of patients investigated for anginal symptoms do not have obstructive coronary artery disease upon diagnostic coronary angiography. These patients are significantly more often female than male and many of them have a dysfunction of the coronary microcirculation as the underlying cause for their symptoms. In this article, we describe gender aspects in clinical conditions with angina despite unobstructed coronary arteries. Moreover, we try to give answers as to why microvascular dysfunction is more prevalent among women than men.

Rate of acute myocardial infarction in patients with troponin-positive chest pain and unobstructed coronary arteries

Background Many patients with troponin-positive chest pain are initially diagnosed with acute myocardial infarction (AMI), but are later found to have nonobstructive coronary artery disease (CAD) by x-ray angiography. CMR may be useful in this diagnostically challenging cohort; the presence and/or pattern of myocardial necrosis identified by CMR may allow differentiation between diverse etiologies such as AMI, myocarditis, Takotsubo cardiomyopathy, among others. AMI may occur despite nonobstructive CAD, since plaque rupture with occlusive thrombosis may be followed by recanalization. Nevertheless, the diagnosis of AMI is critical for patient management. Prior CMR studies of this population report aw ide range in the rate of AMI (5%30%), perhaps because existing studies have limited sample size (20-130 patients). The aim of this study was to determine the rate of AMI in a larger patient population with troponin-positive chest pain and unobstructed coronary arteries and to examine clinical characteristics that may be associated with this diagnosis. Methods This single-center prospective study enrolled consecutive patients who presented with troponin-positive chest pain, had obstructive CAD (>50% stenosis) excluded by invasive coronary angiography, and then were referred for CMR. A comprehensive set of clinical characteristics including CAD risk factors and peak troponin levels were collected. Angiographic atherosclerosis severity was categorized as entirely normal (0%), near-normal (1-25% stenosis), and mild atherosclerosis (>25-50% stenosis). Hyperenhancement in a CAD-pattern on delayed-enhancement CMR was used to determine the diagnosis of AMI.

Transient Myocardial Ischemia During Acetylcholine-Induced Coronary Microvascular Dysfunction Documented by Myocardial Contrast Echocardiography

A 77-year-old white woman was referred for diagnostic coronary angiography after a 6-month history of exertional breathlessness and back pain. Her cardiovascular risk factors were hypercholesterolemia (low-density lipoprotein, 153 mg/dL) and a positive family history for cardiovascular disease (father died at 73 years of age because of a peripheral artery occlusive disease event). Furthermore, the patient was overweight (body mass index, 28.8 kg/m2). Exercise ECG stress testing had to be stopped after 75 W as a result of limiting symptoms (breathlessness) but without ST-segment depression. Diagnostic coronary angiography revealed a 50% plaque in the distal circumflex coronary artery and diffuse minor irregularities in the remaining epicardial vessels (Figure 1). However, there was no flow-limiting epicardial stenosis. Left ventricular angiography showed normal left ventricular function without any wall motion abnormalities at rest, although left ventricular end-diastolic pressure was elevated at 25 mmHg. To further investigate the cause of the patient’s symptoms, intracoronary acetylcholine …

TCT-431 High Prevalence of a Coronary Spasm to Ergonovine Testing in Patients With Stable Angina Pectoris and Unobstructed Coronary Arteries

TCT-431 High Prevalence of a Coronary Spasm to Ergonovine Testing in Patients With Stable Angina Pectoris and Unobstructed Coronary Arteries

Troponin-positive chest pain with unobstructed coronary arteries: definitive differential diagnosis using cardiac MRI

The purpose of this study was to assess the outcome of cardiac MRI (CMRI) with late gadolinium enhancement (LGE) at outpatient follow-up in a consecutive series of patients with troponin-positive chest pain but unobstructed coronary arteries at the index admission. The study group comprised 91 consecutive patients who presented to our institution with cardiac chest pain, elevated troponin I and unobstructed coronary arteries on coronary angiography. All patients underwent an outpatient CMRI with LGE imaging in order to establish a definitive diagnosis. The average time from coronary angiography to LGE-CMRI was 2 months. 73% of patients had no abnormality on their LGE-CMRI, 16% of patients had patchy late enhancement consistent with myocarditis and 11% had focal subendocardial or full thickness late enhancement consistent with myocardial infarction. There were no deaths in this cohort during a mean follow-up of 21 months. LGE-CMRI is a useful tool for establishing whether such patients have definitive evidence of non-ST-segment elevation myocardial infarction (NSTEMI), and can make an important contribution to the long-term management strategy of these patients as an inappropriate diagnosis of NSTEMI carries important medical, social and financial implications.

Chest pain with unobstructed coronary arteries and cardiac syndrome X

The diagnosis of chest pain with unobstructed coronary arteries is found in one third of patients undergoing investigation of chest pain using coronary angiography. Symptoms are often debilitating and sufferers often have a poor quality of life, with frequent and costly demand on health-care services. Although patients with chest pain and unobstructed coronary arteries do not have increased cardiovascular mortality, morbidity is high. The pathophysiology is complex and management often needs to look beyond drug therapies.