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Myocardial bridging (MB) is a congenital coronary anomaly in which a segment of the epicardial coronary artery traverses through the myocardium for a portion of its length. The muscle overlying the artery is termed a myocardial bridge, and the intramyocardial segment is referred to as a tunneled artery. MB can occur in any coronary artery, although is most commonly seen in the left anterior descending artery. Although traditionally considered benign in nature, increasing attention is being given to specific subsets of MB associated with ischemic symptomatology. The advent of contemporary functional and anatomic imaging modalities, both invasive and noninvasive, have dramatically improved our understanding of dynamic pathophysiology associated with MBs. This review provides a contemporary overview of epidemiology, pathobiology, diagnosis, functional assessment, and management of MBs.

Takotsubo syndrome (TS) is an acute and reversible form of myocardial stunning preceded by emotional or physical stress, not explained by an obstruction of an epicardial coronary artery as in acute coronary syndrome. Over the last decades, TS is receiving growing attention, leading to an increase in awareness and diagnostic rate. Chest pain and dyspnea are the most common presenting symptoms; however, nonspecific presentations make the diagnosis challenging for clinicians. Here, we present the case of a 76-year-old female who experienced two completely asymptomatic episodes of TS 20 years apart.

Objectives: Myocardial bridges (MB) are a congenital anomaly in which part of the epicardial coronary artery is intramuscular, known as the presence of myocardium, which causes narrowing of the artery during heart contraction. We aimed to evaluate hemogram parameters (especially platelet indices) in diabetic patients with myocardial bridges. Methods: We reviewed angiograms performed between May 2017 and August 2019 at Bolu Abant Izzet Baysal University Medical Faculty Hospital. After appropriate exclusions, diabetic patients were divided into groups with myocardial bridges and normal coronary artery groups. A total of 124 patients were included in the study and hemogram parameters of these two groups were compared. Kolmogorov Smirnov test was used to examine the normality of variables. Data were compared using univariate tests including independent samples t-test, Mann–Whitney U-test and chi-square test. Results: Compared to control group PDW (17.7 (15.9-19.5) vs.17.4 (16.2-18.9) % p=0.047), MPV (8.3 (6.6-11.4) vs. 7.5 (6.6-8.7) Fl p

Myocardial bridging (MB) is characterised by a segment of a major epicardial coronary artery tunnelling through the myocardium, which is a frequent congenital anomaly, detected in 15–85% of autopsy series and in 0.5–33% of angiographic studies.[1,2][1] MB without critical stenosis is generally

Purpose: Patients with angina and a positive SPECT for reversible ischemia, with no or non-obstructive CAD on ICA represent a frequent clinical problem and predicting prognosis is challenging. Methods: A retrospective single center study focused on patients that underwent elective-ICA with angina and a positive SECT with no or non-obstructive CAD in the CathLab, during a seven-year period. Assessment of patients’ cardiovascular morbidity, mortality, and MACE during a follow-up period of at least three years after ICA, with the assist of a telephone questionnaire.Results: Data of all patients that underwent ICA for a period of 7 years (from January 1,2011 until December 31, 2017) in our hospital were analyzed. The patients that fulfilled the prespecified criteria were 569. At the telephone survey, 285(50.1%) were successfully contacted and agreed to participate. The mean age was 67.6 (SD8.8) years (35.4%female) and the mean follow-up time was 5.53years (SD1.85). Mortality rate was 1.7% (4 patients/non-cardiac causes) and 1,7% rate of revascularization. 31(10,9%) were hospitalized for cardiac reasons and 10,9% patients reported symptoms of HF (no patients with NYHA-Class above II). 21 had arrhythmic events and only two mild anginal symptoms. Noteworthy finding was, the mortality rate in the not-contacted group (12 out of 284, 4,2%), derived by public security records, did not differ significantly from the contacted-group. Conclusions: Patients with angina, a positive SPECT for reversible ischemia and no or non-obstructive CAD in ICA have very good long-term cardiovascular prognosis for at least 5 years.

Described herein are clinical and cardiac morphologic findings in 12 patients (age 43 to 70 years) (7 men) who underwent orthotopic heart transplantation (OHT) because of severe heart failure (HF) resulting from a single large discrete acute myocardial infarct that healed and was associated with severe narrowing of only one major epicardial coronary artery. Most myocardial infarcts are associated with severe narrowing of >1 major epicardial coronary artery and result in smaller myocardial infarcts. Another unusual feature was the total infarction of the ventricular septum in 3 of the 12 patients.

The goal of reperfusion therapies in ST-segment elevation myocardial infarction has evolved to include effective reperfusion of the microcirculation subtended by the culprit epicardial coronary artery. The index of microcirculatory resistance is measured using a pressure- and temperature-sensing coronary guidewire and quantifies microvascular dysfunction. The index of microcirculatory resistance is an independent predictor of microvascular obstruction, infarct size, and adverse clinical outcomes. It has the advantage of being immediately measurable in the catheterization laboratory, before the results of blood biomarkers or noninvasive imaging become available. This provides an opportunity for additional intervention that may alter outcomes. In this review, the authors provide a critical appraisal of the published research on the emerging role of the index of microcirculatory resistance as a tool to guide the stratification of patients for adjunctive therapeutic strategies in acute ST-segment elevation myocardial infarction.

Recent studies reported at TCT Connect 2020 have investigated a number of open clinical questions regarding the role of coronary physiology and the assessment of plaque morphology for diagnosis (FORECAST), risk stratification (COMBINE OCT-FFR) and treatment evaluation (DEFINE-PCI) of patients with coronary artery disease. In this article, the authors provide a critical appraisal of these studies and evaluate how they add to the current evidence base for management of patients with epicardial coronary artery disease. Furthermore, they discuss their potential impact on clinical practice, limitations of these studies and unanswered clinical questions that are areas for future research.

While pharmacologic stress cardiovascular magnetic resonance imaging (MRI) is a robust noninvasive tool in the diagnosis and prognostication of epicardial coronary artery disease, clinical guidelines recommend exercise-based testing in those patients who can exercise. This review describes the development of exercise cardiovascular MRI protocols, summarizes the insights across various patient populations, and highlights future research initiatives. LEVEL OF EVIDENCE: 5 TECHNICAL EFFICACY: Stage 2.

Background Coronary artery spasm is an established cause for angina pectoris. Epicardial coronary spasm may occur in patients with obstructed as well as unobstructed coronary arteries. Previous studies have suggested that epicardial plaque/atherosclerosis is a prerequisite for the development of epicardial spasm. The aim of the present study was to compare the results of intracoronary acetylcholine (ACh) testing in patients with signs and symptoms of myocardial ischemia with completely smooth versus atherosclerotic yet unobstructed epicardial arteries. Methods Between 2008 and 2016 a total number of 617 patients with signs and symptoms of myocardial ischemia yet unobstructed epicardial arteries ( Results There were 389 patients (63%) with completely smooth epicardial arteries. The remaining 228 patients (37%) had non-obstructive epicardial plaques Conclusion In patients with signs and symptoms of myocardial ischemia yet unobstructed coronary arteries the presence of epicardial atherosclerosis is an independent predictor for the occurrence of epicardial spasm but not microvascular spasm on acetylcholine testing. Funding Acknowledgement Type of funding source: Foundation. Main funding source(s): Robert-Bosch-Stiftung, Berthold-Leibinger-Stiftung

Background Coronary functional abnormalities including both epicardial and microvascular coronary artery spasm represent an important role responsible for myocardial ischemia in patients with angina and nonobstructive coronary artery disease. However, clinical characteristics associated with microvascular spasm (MVS) have not been fully evaluated. Purpose The aim of this study was to assess differences in clinical features between patients with MVS and epicardial coronary spasm. Methods A total of 732 consecutive patients with suspected angina who presented nonobstructive coronary arteries and underwent intracoronary acetylcholine provocation test were retrospectively enrolled in this study. Epicardial coronary spasm was defined as total or subtotal occlusion of epicardial coronary arteries accompanied by chest pain and/or ischemic electrocardiographic changes in response to acetylcholine provocation test. MVS was diagnosed when chest pain and/or ischemic electrocardiographic changes developed after administration of acetylcholine in the absence of epicardial coronary spasm. Clinical characteristics were compared between patients with MVS and epicardial coronary spasm. Results Of all patients, 83 patients (11%) had MVS, 367 (50%) had epicardial coronary spasm, and the other patients (39%) showed neither MVS nor epicardial coronary spasm. Patients with MVS tended to be older (65.6±12.7 vs. 63.0±12.3 years, P=0.088) and were more frequently female (60.2% vs. 41.1%, P=0.0016) in comparison with patients with epicardial coronary spasm. Patients with MVS were less likely to be smokers (8.6% vs. 22.9%, P=0.0018), while there were no significant differences in the other coronary risk factors such as hypertension, dyslipidemia, and diabetes mellitus. Serum uric acid were significantly lower in patients with MVS (4.9±1.1 vs. 5.4±1.3 mg/dl, P=0.0018). Conclusion Our study demonstrated that patients with MVS had distinctive clinical background from those with epicardial coronary spasm, suggesting different mechanisms may involve the development of MVS. Funding Acknowledgement Type of funding source: None

Supplemental Digital Content is available in the text., Background: Spontaneous coronary artery dissection (SCAD) occurs when an epicardial coronary artery is narrowed or occluded by an intramural hematoma. SCAD mainly affects women and is associated with pregnancy and systemic arteriopathies, particularly fibromuscular dysplasia. Variants in several genes, such as those causing connective tissue disorders, have been implicated; however, the genetic architecture is poorly understood. Here, we aim to better understand the diagnostic yield of rare variant genetic testing among a cohort of SCAD survivors and to identify genes or gene sets that have a significant enrichment of rare variants. Methods: We sequenced a cohort of 384 SCAD survivors from the United Kingdom, alongside 13 722 UK Biobank controls and a validation cohort of 92 SCAD survivors. We performed a research diagnostic screen for pathogenic variants and exome-wide and gene-set rare variant collapsing analyses. Results: The majority of patients within both cohorts are female, 29% of the study cohort and 14% validation cohort have a remote arteriopathy. Four cases across the 2 cohorts had a diagnosed connective tissue disorder. We identified pathogenic or likely pathogenic variants in 7 genes (PKD1, COL3A1, SMAD3, TGFB2, LOX, MYLK, and YY1AP1) in 14/384 cases in the study cohort and in 1/92 cases in the validation cohort. In our rare variant collapsing analysis, PKD1 was the highest-ranked gene, and several functionally plausible genes were enriched for rare variants, although no gene achieved study-wide statistical significance. Gene-set enrichment analysis suggested a role for additional genes involved in renal function. Conclusions: By studying the largest sequenced cohort of SCAD survivors, we demonstrate that, based on current knowledge, only a small proportion have a pathogenic variant that could explain their disease. Our findings strengthen the overlap between SCAD and renal and connective tissue disorders, and we highlight several new genes for future validation.

This article offers an updated and comprehensive overview of major findings on the effects of statin treatment in patients with chronic angina but without any epicardial coronary artery with obstructive lesion.

When epicardial arteries with minimal CAD do not limit flow are found at coronary angiography, all cardiologists agree that aggressive risk factor modification and use of appropriate drugs are warranted. Some consider plaque sealing of minor coronary lesions with balloon angioplasty to prevent future infarction. Others believe that a coronary lesion that does not cause ischemia should not have the plaque sealed but should have FFR and the non-ischemia producing stenosis should be treated with aggressive risk factor modification (DEFER study). Evidence based data e.g. DEFER, relates to populations, not the individual. Thus these data provide guidelines, which are suggestions for decision making. The weight of evidence favors angioplasty/stent for epicardial vessels that result in myocardial ischemia. Sealing of non flow limiting plaques with angioplasty must await further information derived from invasive and non invasive studies.

We present two cases where fractional flow reserve (FFR) was utilised to guide management of coronary artery fistula (CAF), an approach advocated in recent case studies. CAF is a coronary anomaly that may present with a variety of syndromes though is frequently asymptomatic. When to exclude the fistula (surgically or percutaneously) is not always clear. A way to quantify if the fistula is physiologically meaningful would be advantageous. Our findings suggest FFR may only be assessing the concomitant epicardial coronary artery disease (CAD) rather than the degree of coronary steal and its routine use in this setting is not supported.

Patients with acute myocardial infarction (MI) and nonobstructive coronary artery disease (CAD) have an elevated cardiac event rate, suggesting that these patients may benefit from cardiac medication.We evaluated the rates of cardiac medication use 3 months before angiography and 3 months following clinically indicated angiography for MI in patients with no CAD, nonobstructive CAD, and obstructive CAD. We also examined the sex differences in cardiac medication use 3 months following angiography in patients by extent of angiographic CAD.We studied patients ≥20 years old with MI undergoing coronary angiography in British Columbia, Canada, from January 1, 2008, to March 31, 2010 (n = 3,841). No CAD, nonobstructive CAD, and obstructive CAD were defined as 0%, 1% to 49%, and ≥50% luminal narrowing in any epicardial coronary artery, respectively. Medication use, 3 months before and 3 months following angiography, was obtained through British Columbia PharmaNet for angiotensin-converting enzyme inhibitors (ACE-Is), angiotensin receptor blockers (ARBs), calcium channel blockers (CCBs), beta-blockers, statins, and antiplatelet agents. Optimal medical therapy (OMT) was defined as filled prescriptions for all three: ACE-Is/ARBs, beta-blockers, and statins.Following angiography, in all medication categories except CCBs, patients with no CAD and nonobstructive CAD had significantly lower rates of prescriptions filled than patients with obstructive CAD (all p 0.001). After adjusting for age and prior medication use, patients with nonobstructive CAD were still less likely to receive these medications than patients with obstructive CAD, including OMT with an odds ratio = 0.25 (95% confidence interval: 0.18-0.36). There were no significant sex differences in medication use 3 months postangiography.In post-MI patients, medication use following angiography is significantly lower in nonobstructive CAD than obstructive CAD at 3 months. While sex was not an independent predictor of medication use 3 months post-catheterization, future studies should explore methods of improving medication use in both females and males with nonobstructive CAD post-MI.

Treatment of patients with stable angina and nonobstructive coronary artery disease (CAD) has not been well characterized. We comparatively evaluated medication use in males and females with stable angina with no CAD, nonobstructive CAD, and obstructive CAD.We studied all patients ≥20 years old with stable angina undergoing coronary angiography in British Columbia (BC), Canada, from January 2008 to March 2010 (n = 7,535). No CAD, nonobstructive CAD, and obstructive CAD were defined as 0%, 1%-49%, and ≥50% luminal narrowing in any epicardial coronary artery, respectively. Medication use, 3 months before and 3 months following angiography, was obtained through BC PharmaNet for angiotensin-converting enzyme inhibitors (ACE-I), angiotensin receptor blockers (ARBs), calcium channel blockers (CCBs), beta-blockers, statins, antiplatelet agents, and prescriptions for all three ACE-I/ARBs, beta-blockers, and statins (combination therapy).Following angiography, patients with no and nonobstructive CAD had significantly lower rates of prescription use of all medications, including combination therapy, than patients with obstructive CAD (p 0.001). Use of ACE-I/ARBs, beta-blockers, statins, and combination therapy did not differ by sex, but females had higher use of CCB in all CAD groups, and clopidogrel in nonobstructive and obstructive CAD groups, compared to males.In patients with stable angina, medication use following angiography is low in nonobstructive CAD with only 58.9% prescribed a statin and 19.4% on combination therapy at 3 months. There are no important sex differences in medication use in any CAD category post-angiography. Future studies should explore methods of improving quality of care in patients with nonobstructive CAD.

Background Coronary artery ectasia (CAE) is a segmental dilation of an epicardial coronary artery. Our aim was to evaluate the left atrial (LA) function in patients with CAE. Methods Twenty-seven consecutive patients with CAE and 33 subjects without significant coronary artery disease were included in our study. LA function was evaluated with two-dimensional speckle-tracking echocardiography (2DSTE). Results The systolic, early diastolic and late diastolic strains and strain rates were not statistically significantly different between the two groups. Conclusions Our findings demonstrated that LA function may not be affected by CAE when assessed with 2DSTE. © 2017 Wiley Periodicals, Inc. J Clin Ultrasound 45:231-237, 2017.

Takotsubo syndrome represents an increasingly recognized clinical entity characterized by a reversible acute myocardial dysfunction, often triggered by an emotional or physical stress, and independent of an underlying epicardial coronary artery disease. The diagnosis is often challenging because of the nonspecific clinical presentation and the inconclusive noninvasive diagnostic imaging.The present review provides a brief overview of Takotsubo syndrome clinical presentation and guides the clinician through the diagnostic work-up of Takotsubo syndrome, highlighting clues into differential diagnosis. A review of clinical management is also provided.Despite increasing awareness and recognition, the diagnosis of Takotsubo syndrome remains challenging and Takotsubo syndrome is often underdiagnosed or misdiagnosed. The prompt recognition of Takotsubo syndrome portends relevant prognostic and therapeutic implications.

Coronary vasospasm is characterized by focal or diffuse spasm of an epicardial coronary artery. Definitive diagnosis is usually made with coronary angiography, when resolution of stenosis is observed after administration of intracoronary vasodilators. Coronary vasospasm is rarely a consequence of a blunt force injury to the chest. Among trauma induced cardiac complications, coronary vasospasm has been the least common with only one other reported case of coronary vasospasm induced by trauma. We report a rare case of severe spontaneous coronary vasospasm in a patient with polytrauma successfully treated with intracoronary, intravenous and oral vasodilator therapy. The mechanism is thought to be due to compensatory catecholamine response to trauma, and coronary vasospasm should be strongly suspected in trauma patients with unexplained hypotension, new conduction abnormalities or evidence of ischemia on the ECG. Keywords: Coronary vasospasm, Vasospastic angina, Angina pectoris, Atherosclerotic disease, Polytrauma

To investigate the association between serum C-reactive protein (CRP) levels and coronary collateral circulation (CCC) in Chinese patients with angiography-proven ≥95% coronary stenosis.In this study, 1158 patients with angiography-proven ≥95% occlusion in ≥1 major epicardial coronary artery were enrolled, and then classified into two groups: poor CCC (Rentrop grades 0-1) and good CCC (Rentrop grades 2-3). CRP levels were grouped using the following two models: Model 1 discretized CRP group with 33.33% and 66.66% as the critical values and Model 2 with 1.0 and 3.0 mg/L as the cut off values.There were significant differences in serum CRP levels between the two groups (5.76 ± 3.45 vs. 3.49 ± 2.44 mg/L, respectively; p 0.001), and compared with the first CRP tertile, the risks of poor CCC were higher in the second and third CRP tertiles (OR 2.31, 95%CI [1.67-3.19], OR 6.25, 95%CI [4.52-8.62], respectively). The receiver operating characteristic curve analysis indicated that the optimal cutoff value of CRP to predict poor CCC was 4.21 mg/L with 59.6% sensitivity and 74.33% specificity.CRP levels are an independent predictor for poor CCC and might supply a useful biomarker in clinical applications. Key messages C-reactive protein (CRP) is a non-specific inflammatory marker that is regarded as an independent risk and prognostic factor for individuals who suffer from coronary artery disease (CAD) and cardiovascular disorders. In a Chinese cohort of patients with coronary artery occlusion or stenosis of ≥95% TIMI grade 1 anterograde-flow, the relationship between CRP concentrations and angiographically visible coronary collateral (CC) was assessed. Our data indicated that elevated CRP associated with a significant impairment in CC development, and might supply a useful biomarker in clinical applications.

A myocardial bridge is a segment of an epicardial coronary artery tunneled within the myocardium, which clinically ranges from an incidental finding to an etiology of acute coronary syndrome. Determining the hemodynamic significance with instantaneous wave-free ratio (iFR) can guide medical vs.

It remains unclear if the human coronary vasculature is inherently sensitive to changes in arterial Po2 and Pco2 or if coronary vascular responses are the result of concomitant increases in myocardial O2 consumption/demand ([Formula: see text]). We hypothesized that the coronary vascular response to Po2 and Pco2 would be attenuated in healthy men when [Formula: see text] was attenuated with β1-adrenergic receptor blockade. Healthy men (age: 25 ± 1 yr, n = 11) received intravenous esmolol (β1-adrenergic receptor antagonist) or volume-matched saline in a double-blind, randomized crossover study and were exposed to poikilocapnic hypoxia, isocapnic hypoxia, and hypercapnic hypoxia. Measurements made at baseline and after 5 min of steady state at each gas manipulation included left anterior descending coronary blood velocity (LADV; Doppler echocardiography), heart rate, and arterial blood pressure. LADV values at the end of each hypoxic condition were compared between esmolol and placebo. The rate-pressure product (RPP) and left ventricular mechanical energy (MELV) were calculated as indexes of [Formula: see text]. All gas manipulations augmented RPP, MELV, and LADV, but only RPP and MELV were attenuated (4–18%) after β1-adrenergic receptor blockade ( P < 0.05). Despite attenuated RPP and MELV responses, β1-adrenergic receptor blockade did not attenuate the mean LADV vasodilatory response compared with placebo during poikilocapnic hypoxia (29.4 ± 2.2 vs. 27.3 ± 1.6 cm/s) and isocapnic hypoxia (29.5 ± 1.5 vs. 30.3 ± 2.2 cm/s). Hypercapnic hypoxia elicited a feedforward coronary dilation that was blocked by β1-adrenergic receptor blockade. These results indicate a direct influence of arterial Po2 on coronary vascular regulation that is independent of [Formula: see text]. NEW & NOTEWORTHY In humans, arterial hypoxemia led to an increase in epicardial coronary artery blood velocity. β1-Adrenergic receptor blockade did not diminish the hypoxemic coronary response despite reduced myocardial O2 demand. These data indicate hypoxemia can regulate coronary blood flow independent of myocardial O2 consumption. A plateau in the mean left anterior descending coronary artery blood velocity-rate-pressure product relationship suggested β1-adrenergic receptor-mediated, feedforward epicardial coronary artery dilation. In addition, we observed a synergistic effect of Po2 and Pco2 during hypercapnic hypoxia.

Background: It is important to determine the grade of the coronary collateral circulation (CCC) in patients with stable coronary artery disease. Aim: In this study, we aimed to investigate the relationship between the ischaemia-modified albumin (IMA) level and good CCC. Methods: A total of 95 patients with coronary angiography and at least one epicardial coronary artery obstruction were included in the study. The Rentrop classification was used with CCC grading, where 0 and 1 were defined as poor collateral, and 2 and 3 were defined as good collateral. The IMA level of the patients was measured using an enzyme-linked immunosorbent assay (ELISA). The receiver–operating characteristic curve was used to show the sensitivity and specificity of IMA levels and the optimal cut-off value for predicting good CCC. Results: The multiple logistic regression analysis revealed that the IMA level in the good CCC group was higher (p < 0.045). Conversely, the high-sensitivity C-reactive protein level was lower in the good CCC group (p < 0.023). We found an IMA cut-off value (4.7 ng/mL) that indicated good CCC level, and this shows good CCC with 70.2% sensitivity and 60.3% specificity. Conclusions: The IMA level could serve as a simple and useful predictor of well-developed CCC.

The times, they are a-changin’. —Bob Dylan [(1)][1] Almost 20 years ago, fractional flow reserve (FFR) assessment performed at the time of invasive coronary angiography (ICA) was introduced as a method for identifying and excluding stenoses that reduced epicardial coronary artery flow [(2)][2

Fractional flow reserve (FFR) is the gold standard in the invasive hemodynamic assessment of epicardial coronary artery stenoses. FFR is defined as the ratio of maximal flow achievable in the stenotic coronary artery to the maximal flow achievable in the same coronary artery if it was normal. In other words, FFR informs the clinician to what extent blood flow is reduced and can be improved after revascularization: e.g., a FFR of 0.60 means that coronary blood flow is 60% of what should be in the absence of the epicardial stenosis, and it could improve by 40% after percutaneous coronary intervention.

Rapid and sustained restoration of antegrade flow through the epicardial coronary artery is the primary goal of current treatment of acute ST-segment elevation myocardial infarction (STEMI). It consists of a combination of mechanical recanalization of the occluded artery with primary percutaneous

Myocardial bridging (MB) is characterized by epicardial coronary artery tunneling through the myocardium, with angiographic “milking” and an intravascular ultrasound (IVUS) “half-moon” echolucent [(1)][1]. Optical coherence tomography (OCT), a light-based technique, can provide unprecedented

We present cardiac computed tomography (CT) findings demonstrating apical hypertrophic cardiomyopathy with dystrophic calcification of the left ventricular apex. The absence of significant epicardial coronary artery disease demonstrated by coronary CT angiography suggests that increased wall tension and decreased microvascular perfusion over time account for the dyskinetic apical myocardium, rather than myocardial infarction secondary to atherosclerotic plaque rupture. These observations support CT as the imaging modality of choice to visualize the deposition of calcium in injured myocardial tissue, a recognized occurrence in chronically infarcted myocardium.

Fractional flow reserve (FFR) is an invasive technique used to assess the hemodynamic impact of epicardial coronary artery stenosis, ultimately guiding revascularization. There is significant clinical evidence supporting FFR, but as with any technique, it has subtleties that are important to appreciate when deciding upon the treatment strategy for a given lesion. The background and methodology for measurement of FFR are described in other chapters in this book. In this chapter we will focus on the utility of FFR in situations frequently encountered in the catheterization laboratory and the main clinical evidence to support and guide its use.

An under-recognized cause of chest pain and acute coronary syndromes, the coronary slow flow (CSF) phenomenon is characterized by delayed coronary opacification during diagnostic angiography in the absence of epicardial coronary artery disease or other conditions known to impair coronary flow.

Myocardial bridging (MB) is a congenital anomaly in which a segment of an epicardial coronary artery takes a tunneled intramuscular course under overlying myocardium. Rarely, MB can cause ST elevation myocardial infarction (STEMI). 39 year old male patient presented with 24 hours of typical chest

Race is a component of the Atherosclerotic Cardiovascular Disease (ASCVD) risk score. How ASCVD risk relates to cardiac events and epicardial coronary artery disease (CAD) in blacks vs whites with stable chest pain is not known. The PROMISE trial included 8,764 non-Hispanic blacks (12%; 1,071) and

Slow coronary flow (SCF) phenomenon is a coronary microvascular disorder characterized by the delayed passage of angiographic contrast in the absence of obstructive epicardial coronary artery disease (CAD). Many patients with SCF suffer from angina-like chest pain and present for angiography

The epicardial coronary artery entrapment in thickened serosal pericardium is quite characteristic in tubercular chronic constrictive pericarditis that differentiates this entity from other close differential diagnosis like restrictive, ischemic and dilated cardiomyopathy. The entrapped arteries show a typical motion abnormality. This present case is about tubercular chronic constrictive pericarditis with typical epicardial coronary artery entrapment and its reflection in diagnosis and management outcomes.

Takotsubo cardiomyopathy (TTC) is an increasingly recognized, reversible cardiomyopathy with a clinical presentation that mimics an acute coronary syndrome but without evidence of obstructive coronary lesions. Typical presentation involves chest pain and/or dyspnea, transient ST-segment elevation on the electrocardiogram, and a modest increase in cardiac troponin. Cardiac imaging demonstrates wall-motion abnormalities that extend beyond the territory of a single epicardial coronary artery, and the absence of obstructive coronary lesions. Supportive treatment leads to spontaneous, rapid recovery of ventricular function, but about 10% of patients have recurrent events. This article reviews the defining features and clinical profile of TTC.

Intracoronary acetylcholine provocation testing (ACH-test) is an established method for assessment of epicardial coronary artery spasm in the catheterization laboratory which was introduced more than 30 years ago. Due to the short half-life of acetylcholine it can only be applied directly into the coronary arteries. Several studies have demonstrated the safety and clinical usefulness of this test. However, acetylcholine testing is only rarely applied in the U.S. or Europe. Nevertheless, it has been shown that 62% of Caucasian patients with stable angina and unobstructed coronary arteries on coronary angiography suffer from coronary vasomotor disorders that can be diagnosed with acetylcholine testing. In recent years it has been appreciated that the ACH-test not only assesses the presence of epicardial spasm but that it can also be useful for the detection of coronary microvascular spam. In such cases no epicardial spasm is seen after injection of acetylcholine but ischemic ECG shifts are present together with a reproduction of the patient's symptoms during the test. This article describes the experience with the ACH-test and its implementation in daily clinical routine.

The term ‘microvascular angina’, proposed in the late 1980s, defines patients presenting with symptoms and signs of myocardial ischaemia, despite the presence of angiographically normal coronary arteries. Over the past few decades, evidence has accumulated that indicates the importance of coronary microcirculation abnormalities in the production of myocardial ischemia. Angina pectoris resulting from microvascular abnormalities, in the absence of flow limiting epicardial coronary artery stenoses, is well represented by the name “microvascular angina” (MVA). In patients with angina pectoris but without flow limiting coronary artery disease, MVA has been suggested to be the cause of symptoms and electrocardiographic changes indicative of myocardial ischaemia. MVA that occurs in patients with no cardiovascular or systemic conditions is known as “primary MVA” whereas MVA that occurs in the setting of specific diseases and/or conventional risk factors for coronary artery disease is defined as “secondary MVA”. Both functional and structural abnormalities can affect the coronary microcirculation and lead to MVA. This chapter discusses the clinical importance, diagnosis and mechanisms of this intriguing condition.

Takotsubo cardiomyopathy is characterized by transient systolic ballooning of apical or mid segments of the left ventricle (LV) mimicking acute myocardial infarction in the absence of obstructive epicardial coronary artery disease. Recurrences remain rare and most recurrence case reports are about apical ballooning or typical Takotsubo cardiomyopathy. We present a rare case of recurrence in mid ventricular ballooning or atypical variant of Takotsubo cardiomyopathy. This case highlights the importance of future follow-up and potential of recurrence even in atypical variants.

Ultrasound (US) mediated microbubble (MB) destruction facilitates thrombolysis of the epicardial coronary artery in acute myocardial infarction (AMI) but its effect on microvascular thromboemboli remains largely unexplored. We sought to define the acoustic requirements for effective microvascular sonothrombolysis. To model microembolization, microthrombi were injected and entrapped in a 40 μm pore mesh, increasing upstream pressure, which was measured as an index of thrombus burden. MBs (2.0 × 10 6 MBs/mL) were then infused while pulsed US (1 MHz) was delivered to induce MB destruction immediately adjacent to the thrombus. Upstream pressure decreased progressively during US delivery, indicating a reduction in thrombus burden. More rapid and complete lysis occurred with increasing peak negative acoustic pressure (1.5 MPa > 0.6 MPa) and increasing pulse length (5000 cycles > 100 cycles). Additionally, similar lytic efficacy was achieved at 1.5 MPa without tPA as was at 1.0 MPa with tPA. This model uniquely provides a means to systematically evaluate multiple acoustic and microbubble parameters for the optimization of microvascular sonothrombolysis. This treatment approach for thrombotic microvascular obstruction may obviate the need for adjunctive rt-PA and could have important clinical cost and safety benefits.

Background: Treadmill exercise testing has low specificity for the detection of significant epicardial coronary artery disease (CAD). A possible mechanism to explain some of the false positives is transient subendocardial ischemia induced by intraventricular gradients (IVG) during stress. The development of IVG during dobutamine stress echocardiography (DSE) occurs in 8-38% of non-selected populations. Objectives: To determine: 1. the prevalence of IVG in a selected population of false positives on treadmill stress testing; 2. whether this prevalence is different from that described for non-selected populations; 3. whether patient characteristics are related to the presence of IVG; 4. the relation between the presence of IVG and the occurrence of ECG abnormalities, symptoms and blood pressure. Methods and Results: We evaluated 50 consecutive patients with false positive treadmill stress tests (normal CT coronary angiography, nuclear perfusion tests or angiography) with DSE (2D and Doppler evaluation). All DSE exams were negative for ischemia. Stress-induced IVG was seen in 34 of the 50 patients (68%) and 16 patients (32%) did not develop IVG (p 0.05). However, the presence of IVG was associated with the occurrence of ischemic ST depression during dobutamine stress echo (p 0,05). No entanto, a presença de GIV relacionou-se com a ocorrência de depressão do segmento ST durante o ecocardiograma de sobrecarga com dobutamina (p < 0,05). Conclusões: 1. A prevalência de GIV durante o ecocardiograma de stress com dobutamina em populações seleccionadas de falsos positivos de prova de esforço é muito elevada, ocorrendo em 2/3 dos doentes. 2. Esta prevalência é significativamente mais alta que a descrita para populações não seleccionadas. 3. Idade, género, factores de risco para DAC, terapêutica com beta-bloqueantes/antagonistas dos canais de cálcio, doença arterial significativa/HVE, sintomas e a pressão arterial durante a sobrecarga não se relacionam com a presença ou ausência de GIV. 4. A presença de GIV está relacionada com a ocorrência de alterações isquémicas do segmento ST durante a ecocardiografia de sobrecarga com dobutamina. Keywords: Treadmill stress tests, False positives, Stress echocardiography, Physical exercise, Intraventricular gradient, Palavras-chave: Prova de esforço, Falsos positivos, Ecocardiografia de sobrecarga, Exercício físico, Gradiente intraventricular

Coronary microvascular dysfunction (CMVD) can mediate angina and myocardial ischemia in a proportion of patients presenting with signs and symptoms of myocardial ischemia in the absence of obstructive epicardial coronary artery disease (CAD). Previous studies have shown sex based difference in

Fractional flow reserve (FFR) has become the reference standard for assessing the functional significance of epicardial coronary artery disease in the cardiac catheterization laboratory. Recently an alternative microcatheter derived fractional flow reserve (FFRMC) system has been developed. However