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Concept: Left coronary artery

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BACKGROUND: Type VI dual left anterior descending artery (LAD) is a rare coronary anomaly, the first case of which has recently been described. This is the first report of type VI dual LAD anomaly in which the patient presented with non-ST-segment elevation myocardial infarction and percutaneous coronary intervention was performed in the anomalously originating LAD. CASE PRESENTATION: A 52-year-old man with diabetes, hypertension and hyperlipidemia presented with chest pain without ST elevation on EKG, although the patient’s troponin I level was elevated. Coronary angiography revealed a short LAD originating from the left main coronary artery and a long LAD originating from the proximal portion of the right coronary artery (RCA). Three-dimensional reconstruction of computed tomography of images revealed that the long LAD originated from the proximal RCA and coursed between the right ventricular outflow tract (RVOT) and the aortic root before entering the mid anterior interventricular groove. The high take-off RCA originated underneath the RVOT, pointing downwards and forming an acute angle with the proximal portion of the long LAD. The anomalous long LAD displayed significant stenosis. We performed successful percutaneous coronary intervention (PCI) in the anomalous artery. CONCLUSION: With accurate understanding of the coronary anatomy and appropriate hardware selection, successful PCI can be performed in the in the long LAD in patients with type VI dual LAD anomaly.

Concepts: Myocardial infarction, Atherosclerosis, Angina pectoris, Cardiology, Heart, Atheroma, Cardiovascular system, Left coronary artery

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Background: The polygon of confluence (POC) represents the zone of confluence of the distal left main (LM), ostial left anterior descending (LAD), and ostial left circumflex (LCX) arteries. Methods: We used intravascular ultrasound (IVUS) to assess the POC pre and post-drug-eluting stent implantation for unprotected distal LM disease. Four segments within 82 LM bifurcation lesions were defined by longitudinal IVUS reconstruction: (1) ostial LAD, (2) POC, and (3) distal LM (DLM)-from LAD-pullback, and (4) ostial LCX from LCX-pullback. Results: Preprocedural minimum lumen area (MLA) and poststenting minimum stent area (MSA) within the LM were mainly located within the POC (51 and 71%). On ROC analysis, a cut-off of the MLA within the POC of 6.1 mm(2) predicted significant LCX carinal stenosis (85% sensitivity, 52% specificity, AUC = 0.7, 95% CI = 0.57-0.78, P < 0.01). Poststenting MSA within the distal LM proximal to the carina (to include DLM and POC) positively correlated with the preprocedural MLA within the POC (r = 0.283, P = 0.02); it was significantly smaller in 48 lesions with a pre-PCI MLA within the POC < 6.1 mm(2) versus 25 lesions with a pre-PCI MLA ≥6.1 mm(2) (7.5 ± 2.1 mm(2) vs. 8.6 ± 2.0 mm(2) , P = 0.04). Independent predictors for poststenting LCX carinal MLA also included preprocedural MLA within the POC (β = 0.240, 95% CI = 0.004-0.353, P = 0.04). Conclusion: The MLA within the POC was a good surrogate reflecting the overall severity of LM bifurcation disease including ostial LCX stenosis pre-PCI and the ability to expand a stent within the distal LM as well as final ostial LCX lumen area post-PCI. © 2011 Wiley Periodicals, Inc.

Concepts: Blood, Myocardial infarction, Atherosclerosis, Prediction, Artery, Vein, Left coronary artery, Intravascular ultrasound

9

Background: The occurrence of a distinctive perineal eruption that appears early in infants with Kawasaki disease (KD), the most relevant type of febrile vasculitis of childhood, has received little attention in pediatric reports. KD diagnosis is based on clinical criteria, which can be supported by laboratory abnormalities or positive echocardiography findings: difficulty in diagnosis can be increased by incomplete or atypical presentations, but a timely diagnostic process is essential in the youngest patients who are more prone to the risk of cardiac sequelae resulting from KD. Case Presentation: In this report, we present the case of a 2-month-old infant with an unusual presentation of KD, in whom diagnosis was made despite fever remission on the fourth day of hospitalization following intravenous corticosteroid therapy to treat concomitant bronchoconstriction. The presence of early desquamating perineal erythema led to the consideration of KD diagnosis, confirmed by the echocardiographic assessment of right and left coronary artery dilatations with pericardial effusion on the fifth day of hospital stay. Conclusions: Diagnosis of KD represents a demanding challenge, mainly when the illness starts with an incomplete or nuanced presentation. An erythematous desquamating perineal rash is a valuable early clinical clue, which might facilitate a prompt diagnosis of KD. This case emphasizes that an accurate assessment of all clinical features, including perineal erythema with early tendency to desquamation, and an eventual echocardiography, are necessary in an infant displaying fever to corroborate the suspicion of KD.

Concepts: Cardiology, Heart, Artery, Coronary circulation, Left coronary artery, Aspirin, Pediatrics, Kawasaki disease

8

Anomalous aortic origin of a coronary artery (AAOCA) from the inappropriate sinus of Valsalva is increasingly recognized by cardiac imaging. Although most AAOCA subtypes are benign, autopsy studies report an associated risk of sudden death with interarterial anomalous left coronary artery (ALCA) and anomalous right coronary artery (ARCA). Despite efforts to identify high-risk ALCA and ARCA patients who may benefit from surgical repair, debate remains regarding their classification, prevalence, risk stratification, and management. We comprehensively reviewed 77 studies reporting the prevalence of AAOCA among >1 million patients, and 20 studies examining outcomes of interarterial ALCA/ARCA patients. Observational data suggests that interarterial ALCA is rare (weighted prevalence = 0.03%; 95% confidence interval [CI]: 0.01% to 0.04%) compared with interarterial ARCA (weighted prevalence = 0.23%; 95% CI: 0.17% to 0.31%). Recognizing the challenges in managing these patients, we review cardiac tests used to examine AAOCA and knowledge gaps in management.

Concepts: Heart, Artery, Coronary circulation, Cardiovascular system, Left coronary artery, Ascending aorta, Arteries of the thorax

3

Disrupted atherosclerotic plaques in the left anterior descending coronary artery are discussed controversially as a potential pathophysiological mechanism in Takotsubo syndrome (TTS). Therefore, the aim of the present study was to assess plaque burden and morphology by using optical coherence tomography in patients with TTS.

Concepts: Atherosclerosis, Angina pectoris, Cardiology, Atheroma, Artery, Coronary circulation, Left coronary artery

3

Despite the importance of collateral vessels in human hearts, a detailed analysis of their distribution within the coronary vasculature based on three-dimensional vascular reconstructions is lacking. This study aimed to classify the transmural distribution and connectivity of coronary collaterals in human hearts. One normotrophic human heart and one hypertrophied human heart with fibrosis in the inferior wall from a previous infarction were obtained. After filling the coronary arteries with fluorescent replica material, hearts were frozen and alternately cut and block-face imaged using an imaging cryomicrotome. Transmural distribution, connectivity, and diameter of collaterals were determined. Numerous collateral vessels were found (normotrophic heart: 12.3 collaterals/cm(3); hypertrophied heart: 3.7 collaterals/cm(3)), with 97% and 92%, respectively, of the collaterals located within the perfusion territories (intracoronary collaterals). In the normotrophic heart, intracoronary collaterals {median diameter [interquartile range (IQR)]: 91.4 [73.0-115.7] μm} were most prevalent (74%) within the left anterior descending (LAD) territory. Intercoronary collaterals [median diameter (IQR): 94.3 (79.9-107.4) μm] were almost exclusively (99%) found between the LAD and the left circumflex artery (LCX). In the hypertrophied heart, intracoronary collaterals [median diameter (IQR): 101.1 (84.8-126.0) μm] were located within both the LAD (48%) and LCX (46%) territory. Intercoronary collaterals [median diameter (IQR): 97.8 (89.3-111.2) μm] were most prevalent between the LAD-LCX (68%) and LAD-right coronary artery (28%). This study shows that human hearts have abundant coronary collaterals within all flow territories and layers of the heart. The majority of these collaterals are small intracoronary collaterals, which would have remained undetected by clinical imaging techniques.

Concepts: Blood, Atherosclerosis, Heart, Blood vessel, Atheroma, Artery, Coronary circulation, Left coronary artery

2

A myocardial bridge (MB) is the term for the muscle overlying the intramyocardial segment of the epicardial coronary artery (referred to as a tunneled artery). Although MBs can be found in any epicardial artery, most of them involve the left anterior descending artery. These congenital coronary anomalies have long been recognized anatomically, and are traditionally considered a benign condition; however, the association between myocardial ischemia and MBs has increased their clinical relevance. This review summarizes the prevalence, pathophysiology, and diagnostic findings, including morphological, functional assessment, and treatment of patients with MB involving the left anterior descending artery, suggesting a pragmatic clinical approach to this entity.

Concepts: Myocardial infarction, Heart, Artery, Coronary circulation, Cardiovascular system, Left coronary artery

2

INTRODUCTION: Reverse takotsubo cardiomyopathy is a rare variant of classic takotsubo cardiomyopathy that presents within a different patient profile and with its own hemodynamic considerations. Its recognition is important for prognostic, evaluation and treatment considerations. CASE PRESENTATION: Case 1: A 69-year-old Caucasian woman presented with substernal chest pain following a motor vehicle accident. During her evaluation, she was found to have positive results for cardiac enzymes and underwent left heart cardiac catheterization. The results of the catheterization demonstrated no significant coronary stenosis. However, her ventriculogram showed basal and anterior akinesis.Case 2: A 62-year-old Caucasian woman began having substernal chest pain that radiated to her shoulder blades. She was taken to a local area hospital where she was found to have elevated troponins. A left heart catheterization showed an ejection fraction of 35% with hypokinesis of the anterior and posterobasal walls of her heart, with 30% stenosis of her left anterior descending artery but no other significant coronary artery stenosis. CONCLUSION: The cases in this report illustrate a lesser-known variant of takotsubo cardiomyopathy.

Concepts: Myocardial infarction, Atherosclerosis, Cardiology, Heart, Artery, Coronary circulation, Left coronary artery, Cardiac catheterization

1

Background -Although invasive physiologic assessment for coronary stenosis has become a standard practice to guide treatment strategy, coronary circulatory response and changes in invasive physiologic indices, according to different anatomical and hemodynamic lesion severity, have not been fully demonstrated in patients with coronary artery disease. Methods -One hundred fifteen patients with left anterior descending artery stenosis who underwent both (13)N-ammonia positron emission tomography (PET) and invasive physiologic measurement were analyzed. Myocardial blood flow (MBF) measured using PET and invasively measured coronary pressures were used to calculate microvascular resistance (MVR) and stenosis resistance. Results -With progressive worsening of angiographic stenosis severity, both resting and hyperemic trans-stenotic pressure gradient and stenosis resistance increased (P<0.001 for all) and hyperemic MBF (P<0.001) and resting MVR (P=0.012) decreased. Resting MBF (P=0.383) and hyperemic MVR (P=0.431) were not changed and maintained stable. Both fractional flow reserve (FFR) and instantaneous wave free ratio (iFR) decreased as angiographic stenosis severity, stenosis resistance, and trans-stenotic pressure gradient increased, and hyperemic MBF decreased (all P values<0.001). When the presence of myocardial ischemia was defined by both low hyperemic MBF and low coronary flow reserve (CFR), the diagnostic accuracy of FFR and iFR did not differ, regardless of cut-off values of hyperemic MBF and CFR. Conclusions -This study demonstrated how the coronary circulation changes in response to increasing coronary stenosis severity using (13)N-ammonium PET-derived MBF and invasively measured pressure data. Currently used resting and hyperemic pressure-derived invasive physiologic indices have similar patterns of relationships to the different anatomic and hemodynamic lesion severity. Clinical Trial Registration -URL: https://clinicaltrials.gov Unique Identifier: NCT01366404.

Concepts: Myocardial infarction, Atherosclerosis, Angina pectoris, Heart, Positron emission tomography, Coronary circulation, Cardiovascular system, Left coronary artery

1

Adenosine-assisted transthoracic Doppler-derived coronary flow reserve (TDE-CFR) reflects coronary vascular function. The prognostic and incremental value of left anterior descending coronary artery TDE-CFR above myocardial perfusion scintigraphy in patients with suspected myocardial ischemia has not yet been studied.

Concepts: Myocardial infarction, Heart, Artery, Coronary circulation, Cardiovascular system, Left coronary artery