Noninvasive Cardiac Imaging Techniques Research Articles

Assessment of Tricuspid Regurgitation by Cardiac Magnetic Resonance Imaging: Current Role and Future Applications.

Tricuspid regurgitation (TR) is a prevalent valvular disease with a significant mortality rate. The evaluation of TR severity and associated right heart remodeling and dysfunction is crucial to determine the optimal therapeutic strategy and to improve prognosis. While echocardiography remains the first-line imaging technique to evaluate TR, it has many limitations, both operator- and patient-related. Cardiovascular magnetic resonance imaging (CMR) has emerged as an innovative and comprehensive non-invasive cardiac imaging technique with additional value beyond routine echocardiographic assessment. Besides its established role as the gold standard for the evaluation of cardiac volumes, CMR can add important insights with regard to valvular anatomy and function. Accurate quantification of TR severity, including calculation of regurgitant volume and fraction, can be performed using either the well-known indirect volumetric method or novel 4D flow imaging. In addition, CMR can be used to assess the impact on the right heart, including right heart remodeling, function and tissue characterization. Several CMR-derived parameters have been associated with outcome, highlighting the importance of multi-modality imaging in patients with TR. The aim of this review is to provide an overview of the current role of CMR in the assessment and management of patients with TR and its future applications.

Cardiac reverse remodelling by imaging parameters with recent changes to guideline medical therapy in heart failure.

Recently established heart failure therapies, including sodium glucose co-transporter 2 inhibitors, angiotensin-neprilysin inhibitors, and cardiac resynchronization therapy, have led to both clinical and structural improvements. Reverse remodelling describes the structural and functional responses to therapy and has been shown to correlate with patients' clinical response, acting as a biomarker for treatment success. The introduction of these new therapeutic agents in addition to advances in non-invasive cardiac imaging has led to an expansion in the evaluation and the validation of cardiac reverse remodelling. Methods including volumetric changes as well as strain and myocardial work have all been shown to be non-invasive end-points of reverse remodelling, correlating with clinical outcomes. Our review summarizes the current available evidence on reverse remodelling in heart failure by the non-invasive cardiac imaging techniques, in particular transthoracic echocardiography.

Use of attr cardiac amyloidosis imaging in latin america

Abstract Funding Acknowledgements Type of funding sources: None. Background/Introduction Transthyretin amyloid cardiomyopathy (ATTR-CM) is associated with high morbidity and mortality(1). Non-invasive imaging techniques and novel treatments allow for a better prognosis, but a lack of clinical awareness of the proper use of imaging delays appropriate diagnosis and management. Since 2019, when the multi-society expert consensus on recommendations for multimodality imaging in cardiac amyloidosis (2) was published, multiple international societies have also published their position (3) making imaging techniques such as nuclear medicine scintigraphy (NMS), cardiac magnetic resonance (CMR) and transthoracic echocardiogram (TTE) the methods of choice for the diagnosis of ATTR-CM. Purpose We aim to know how non-invasive imaging methods are used to diagnose ATTR-CM in Latin America (LA) Methods Anonymous online surveys were distributed digitally among clinicians across LA for two months (June-July 2021). We asked about the availability and use of non-invasive cardiac imaging techniques to diagnose ATTR-CA. The information was automatically entered into a spreadsheet for tabulation and descriptive statistical analysis (Microsoft Excel 2016). Results Surveys were collected from 82 NM centers and 406 clinicians (mainly cardiologists, 65%), with responses from professionals from 17 of the 20 LA countries. The diagnostic image most available among the respondents was NMS (100%), followed by TTE ( 86%), and the last, CMR (76%). Fig 1. All nuclear medicine centers have access to perform SPECT acquisition, but advanced technology is lacking in some areas (SPECT/CT-44%, CZT-7%). Of the available phosphonates, PYP is accessible in most centers (83%); a minority use HMPD (12%), and just four centers use MDP (5%). Regarding TTE availability, only 59% can perform advanced techniques as GLS. Something similar happens in the availability of CMR since only 42% have access to advances sequences as mapping. When we presented a clinical scenario of a patient with a suspicious ETT of ATTR-CM, the following main study to request was CMR (43%), and only 38% considered NMS as the next one. 65% of the clinician's responders had not ordered a single NMS during the year before the survey. Of the remaining 35% who had requested the procedure, 27% had ordered 1–5 studies, and only 4% more than 10. The five countries where more NMS are acquired are Brazil, Argentina, Chile, Colombia, and Mexico. Fig 2. Conclusion(s) We present a representative sample of what happens in LA regarding the use of non-invasive imaging to diagnose ATTR-CM. Essential diagnostic imaging resources are reasonably available in the region but are under-utilized, probably because of the limited awareness of clinicians. Advance technology such as SPECT/CT, CZT, strain, and mapping are lacking; investment in technological infrastructure is needed. The survey demonstrated the need for educational programs to increase the utilization of diagnostic imaging in ATTR-CM.

Right heart catheterization in Italian catheterization laboratories: results of the SICI-GISE national survey promoted by the GISE Young Committee

Over the past decades, the improvements in the diagnostic power and availability of non-invasive cardiac imaging techniques have led to a decline of right heart catheterization (RHC) performance. However, RHC remains the gold standard for diagnosing pulmonary hypertension and an essential tool for the evaluation of patient candidacy to heart transplantation. This survey was carried out jointly by the Young Committee of GISE, with the support of the SICI-GISE Society, and the ICOT group, with the aim of evaluating how the interventional cardiology community perform RHC. A web-based questionnaire based on 20 questions was distributed to SICI-GISE members. The survey was distributed to 1550 physicians with 174 (11%) responses. Most centers perform few procedures per year (<10 RHC/year) and a dedicated cardiologist is usually lacking. Patients were frequently admitted as ordinary hospitalization regimen and the most frequent indication for RHC was the hemodynamic assessment of pulmonary hypertension, followed by diagnostics of valvular diseases and advanced heart failure/heart transplantation. Indeed, the majority of participants (86%) are involved in transcatheter procedures for structural heart disease. The average time taken to perform the RHC was approximately 30-60 min. The femoral access (60%) was the most frequently used, usually by an echo-guided approach. Two-thirds of participants discontinued oral anticoagulant therapy before RHC. Only 27% of centers assess wedge position from an integrated analysis. Furthermore, the edge pressure is detected in the end-diastolic cardiac phase in half cases and in the end-expiratory phase in only 31%. The most commonly used method for cardiac output calculation was the indirect Fick method (58%). Guidance on the best practice for performing RHC is currently lacking. A more precise standardization of this demanding procedure is warranted.

Sex-Specific Stress Perfusion Cardiac Magnetic Resonance Imaging in Suspected Ischemic Heart Disease: Insights From SPINS Retrospective Registry

BackgroundCardiovascular disease (CVD) remains the leading cause of mortality in women, but current noninvasive cardiac imaging techniques have sex-specific limitations. ObjectivesIn this study, the authors sought to investigate the effect of sex on the prognostic utility and downstream invasive revascularization and costs of stress perfusion cardiac magnetic resonance (CMR) for suspected CVD. MethodsSex-specific prognostic performance was evaluated in a 2,349-patient multicenter SPINS (Stress CMR Perfusion Imaging in the United States [SPINS] Study) Registry. The primary outcome measure was a composite of cardiovascular death and nonfatal myocardial infarction; secondary outcomes were hospitalization for unstable angina or heart failure, and late unplanned coronary artery bypass grafting. ResultsSPINS included 1,104 women (47% of cohort); women had higher prevalence of chest pain (62% vs 50%; P < 0.0001) but lower use of medical therapies. At the 5.4-year median follow-up, women with normal stress CMR had a low annualized rate of primary composite outcome similar to men (0.54%/y vs 0.75%/y, respectively; P = NS). In contrast, women with abnormal CMR were at higher risk for both primary (3.74%/y vs 0.54%/y; P < 0.0001) and secondary (9.8%/y vs 1.6%/y; P < 0.0001) outcomes compared with women with normal CMR. Abnormal stress CMR was an independent predictor for the primary (HR: 2.64 [95% CI: 1.20-5.90]; P = 0.02) and secondary (HR: 2.09 [95% CI: 1.43-3.08]; P < 0.0001) outcome measures. There was no effect modification for sex. Women had lower rates of invasive coronary angiography (3.6% vs 7.3%; P = 0.0001) and downstream costs ($114 vs $171; P = 0.001) at 90 days following CMR. There was no effect of sex on diagnostic image quality. ConclusionsStress CMR demonstrated excellent prognostic performance with lower rates of invasive coronary angiography referral in women. Stress CMR should be considered as a first-line noninvasive imaging tool for the evaluation of women. (Stress CMR Perfusion Imaging in the United States [SPINS] Study [SPINS]; NCT03192891)

Patient Selection and Clinical Indication for Chronic Total Occlusion Revascularization-A Workflow Focusing on Non-Invasive Cardiac Imaging.

Percutaneous coronary intervention of chronic total occlusion (CTO PCI) is a challenging procedure with high complication rates and, as not yet fully understood long-term clinical benefits. Ischemic symptom relief in patients with high ischemic burden is to date the only established clinical indication to undergo CTO PCI, supported by randomized controlled trials. In this context, current guidelines suggest attempting CTO PCI only in non-invasively assessed viable CTO correspondent myocardial territories, with large ischemic areas. Hence, besides a comprehensive coronary angiography lesion evaluation, the information derived from non-invasive cardiac imaging techniques is crucial to selecting candidates who may benefit from the revascularization of the occluded vessel. Currently, there are no clear recommendations for a non-invasive myocardial evaluation or choice of imaging modality pre-CTO PCI. Therefore, selecting among available options is left to the physician's discretion. As CTO PCI is strongly recommended to be carried out explicitly in experienced centers, full access to non-invasive imaging for risk-benefit assessment as well as a systematic institutional evaluation process has to be encouraged. In this framework, we opted to review the current myocardial imaging tools and their use for indicating a CTO PCI. Furthermore, based on our experience, we propose a cost-effective systematic approach for myocardial assessment to help guide clinical decision-making for patients presenting with chronic total occlusions.

A Comprehensive Assessment of Cardiomyopathies through Cardiovascular Magnetic Resonance: Focus on the Pediatric Population.

Cardiomyopathies (CMPs) are a heterogeneous group of diseases that involve the myocardium and result in systolic or diastolic impairment of the cardiac muscle, potentially leading to heart failure, malignant arrhythmias, or sudden cardiac death. Occurrence in pediatric age is rare but has been associated with worse outcomes. Non-invasive cardiac imaging techniques, integrated with clinical, genetic, and electrocardiographic data, have shown a pivotal role in the clinical work-up of such diseases by defining structural alterations and assessing potential complications. Above all modalities, cardiovascular magnetic resonance (CMR) has emerged as a powerful tool complementary to echocardiography to confirm diagnosis, provide prognostic information and guide therapeutic strategies secondary to its high spatial and temporal resolution, lack of ionizing radiation, and good reproducibility. Moreover, CMR can provide in vivo tissue characterization of the myocardial tissue aiding the identification of structural pathologic changes such as replacement or diffuse fibrosis, which are predictors of worse outcomes. Large prospective randomized studies are needed for further validation of CMR in the context of childhood CMPs. This review aims to highlight the role of advanced imaging with CMR in CMPs with particular reference to the dilated, hypertrophic and non-compacted phenotypes, which are more commonly seen in children.

Cardiac Imaging on COVID-19 Pandemic Era: the Stand, The Lost, and Found

Purpose of ReviewThe present review will outline the main effects of COVID-19 pandemic on cardiovascular pathologies, focusing on the role of modern non-invasive cardiac imaging techniques in this setting.Recent FindingsMultimodality cardiac imaging seems particularly suited for the in-depth characterization of patients with COVID-19, allowing the assessment of the variegated impact of the disease on the different aspects of myocardial perfusion, structure, and function.SummaryThe infection of SARS-CoV-2, leading to the coronavirus disease-19 (COVID-19), has represented a consistent challenge for the organization of the healthcare systems, associating to a significant increase of the fatality rate of different acute and chronic disease. Moreover, the reallocation of healthcare providers led to a significant reduction of the availability of tests and therapies, with the deferral of non-urgent tests and non-lifesaving procedures.

State-of-the-art modalities in cardio-oncology: insight from a nuclear medicine approach.

Cancer and cardiovascular disease are the most significant causes of morbidity and mortality worldwide. Although the cancer survival rate has increased due to improved treatment approaches, especially targeted therapy, some side effects such as cardiotoxicity decrease the efficiency of the clinical outcome. Radiation therapy and chemotherapy have a long-established history of potential cardiotoxic effects. A new multi-disciplinary and translational field known as cardio-oncology has been developed for the identification, prevention, and treatment of cardiovascular dysfunctions associated with cancer treatment approaches. One of the important tools for detecting and monitoring cardiotoxic effects is non-invasive nuclear cardiac imaging techniques. Cardiac nuclear imaging modalities especially recent findings positron emission tomography (PET) tracers have a quintessential role in the early detection of cardiovascular disorders. Moreover, comprehensive studies are required to investigate novel nuclear medicine treatment approaches such as peptide receptor radionuclide therapy (PRRT), fibroblast activation protein (FAP), and chemokine receptor (CXCR) targeting probes for possible cardiac side effects that play important roles in the treatment of malignancies.

A Tako-Tsubo syndrome case managed with robotic telechocardiography during the containment due to the covid-19 pandemic

IntroductionThis clinical case reports a Tako-Tsubo syndrome, in a 48-year-old single woman without cardiovascular history, without COVID symptoms, admitted with acute heart failure to the emergency room of the hospital of Marie-Galante (CHSM), an island of the Guadeloupe archipelago, confined due to the COVID-19 pandemic. The treatment of the congestive phase then the background outpatient treatment of the heart failure were initiated, on the spot thanks to cardiological teleconsultation (TLC) and robotized telechocardiography (TER).MethodThe TER device (Melody ®) is a non-invasive remote cardiac imaging technique, configured as follows: the expert site (CHU Guadeloupe), the patient site (CHSM). The articulated arm of the robot, equipped with the echocardiography probe on its outside, is positioned on the patient's thorax by the tele-assistant nurse. The cardiologist takes the dummy probe in hand and remotely controls the robot, which reproduces the movements of his or her hand precisely and synchronously. The digital control unit and the reading of the echographic image allow him to parameterize the echocardiography in real time. The videoconference (Courbaril ®) allows the dialogue between the cardiologist and the patient or the tele-assistant nurse (Fig. 1).ResultsThe first TER mainly showed a dilated cardiomyopathy, a LV severely hypokinetic, the LV ejection fraction was estimated to 15–20%, with a moderate intra LV contrast, and high LV filling pressures. The RV was dilated, moderately hypokinetic. A PAH at 76 mmHg. A moderate pericardial and bilateral pleural effusion. Few pulmonary comet tails. The second TER, performed 6 weeks later showed a normalization of the LV size with improved ejection fraction to 58%.ConclusionSix TLC using 2 TER enabled the patient to be managed without medical evacuation to the CHU Guadeloupe during the containment due to COVID-19 pandemic. The TER system (robotized Tele echocarcardiography)

The Role of Multimodality Imaging in Cardiac Sarcoidosis.

The etiology and the progression of sarcoidosis remain unknown. However, cardiac sarcoidosis (CS) is significantly associated with a poor prognosis due to the associated congestive heart failure, arrhythmias (such as an advanced atrioventricular block), and ventricular tachyarrhythmia. Novel imaging modalities are now available to detect CS lesions secondary to active inflammation, granuloma formation, and fibrotic changes. 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) and cardiac magnetic resonance imaging (CMR) play essential roles in diagnosing and monitoring patients with confirmed or suspected CS. The following focused review will highlight the emerging role of non-invasive cardiac imaging techniques, including FDG PET/CT and CMR.

Coronary Microvascular Dysfunction and the Role of Noninvasive Cardiovascular Imaging.

Patients with coronary microvascular dysfunction (CMD) have significantly higher rates of cardiovascular events, including hospitalization for heart failure, sudden cardiac death, and myocardial infarction (MI). In CMD, several pathophysiological changes lead to functional and structural abnormalities in the coronary microvasculature, which disrupt the ability of the vessels to vasodilate and augment myocardial blood flow in response to increased myocardial oxygen demand, causing ischemia and angina. With the advent of more advanced non-invasive cardiac imaging techniques, the coronary microvasculature has been subjected to more intense study in the past two decades—this has led to further insights into the diagnosis, pathophysiology, treatment, prognosis and follow-up of CMD. This review will highlight and compare the salient features of the currently available non-invasive imaging modalities used in these patients, and discuss the clinical utility of these techniques in the workup and management of these patients.

Follow-Up After Myocardial Infarction toExplore the Stability of Arrhythmogenic Substrate: The Footprint Study.

This study aimed to characterize the long-term scar remodeling process after an acute myocardial infarction (AMI) and the underlying scar-related arrhythmogenic substrate using serial late gadolinium enhancement cardiac magnetic resonance (LGE-CMR). Little is known about the time course needed for completion of the scar healing process after an AMI, which can be assessed by noninvasive cardiac imaging techniques such as LGE-CMR. Fifty-six patients with revascularized ST-segment elevation AMI (STEMI) were consecutively included. LGE-CMR (3-T) was obtained at 7days, 6months, and 4 years after STEMI. The myocardium was segmented into 10 layers from the endocardium to epicardium, characterizing the core, border zone (BZ), and BZ channels (BZCs) using a dedicated post-processing software. Mean age of the patients was 57 ± 11 years; 77% were men. Left ventricular ejection fraction improved at 6months from 47% to 51% (p<0.001) and remained stable at 4 years (53%; p=0.21). Total scar mass decreased from 20.3 ± 14.6g to 15.3 ± 13.3g (6months) and to 12.7 ± 11.7g (4 years) (p<0.001). Thirty of 56 (53%) patients showed a mean of 1.5 ± 1.3 BZCs/patient at 7days, decreasing to 1.2 ± 1.3 (6months) and 0.8 ± 1.0 (4 years) (p<0.01). Only 42% of the initial BZCs remained present after 4 years. There were no arrhythmic events after a mean follow-up of 62.5 ± 7.4months. CMR data post-processing permitted a dynamic assessment of quantitative and qualitative post-AMI scar characteristics. Scar size and number of BZCs steadily decreased 4 years after AMI. BZC distribution was significantly modified during this time. These dynamic parameters could be reliably assessed with CMR; their evaluation might be of prognostic value.

Viabilidad miocárdica: multimodalidad – resonancia magnética cardíaca

Left ventricular dysfunction in ischaemic heart disease can occur due to stunning, hibernation, or necrosis. The non-invasive cardiac imaging techniques evaluate different objectives in the identification of potentially viable myocardium, by varying their sensitivity and specificity in order to identify them. This makes it very difficult to extrapolate myocardial viability studies between different modes. Cardiac magnetic resonance can help to evaluate by its biphasic response to dobutamine, or by gadolinium uptake in the ventricular myocardium. The most used technique is the late gadolinium enhancement, in which the transmurality of the necrosis is evaluated as a prognostic factor in the recovery of myocardial contractility.

Machine-readable Yin-Yang imbalance: traditional Chinese medicine syndrome computer modeling based on three-dimensional noninvasive cardiac electrophysiology imaging.

ObjectivesThe principal diagnostic methods of traditional Chinese medicine (TCM) are inspection, auscultation and olfaction, inquiry, and pulse-taking. Treatment by syndrome differentiation is likely to be subjective. This study was designed to provide a basic theory for TCM diagnosis and establish an objective means of evaluating the correctness of syndrome differentiation.MethodsWe herein provide the basic theory of TCM syndrome computer modeling based on a noninvasive cardiac electrophysiology imaging technique. Noninvasive cardiac electrophysiology imaging records the heart’s electrical activity from hundreds of electrodes on the patient’s torso surface and therefore provides much more information than 12-lead electrocardiography. Through mathematical reconstruction algorithm calculations, the reconstructed heart model is a machine-readable description of the underlying mathematical physics model that reveals the detailed three-dimensional (3D) electrophysiological activity of the heart.ResultsFrom part of the simulation results, the imaged 3D cardiac electrical source provides dynamic information regarding the heart’s electrical activity at any given location within the 3D myocardium.ConclusionsThis noninvasive cardiac electrophysiology imaging method is suitable for translating TCM syndromes into a computable format of the underlying mathematical physics model to offer TCM diagnosis evidence-based standards for ensuring correct evaluation and rigorous, scientific data for demonstrating its efficacy.

Cardiac amyloidosis: Recent advances in the diagnosis and therapy.

Cardiac amyloidosis (CA) is a progressive cardiomyopathy in which misfolded endogenous proteins form amyloid fibrils that deposit in the heart as well as kidneys, liver, gastrointestinal tract and soft tissues. The most common forms of CA include immunoglobulin light chain (AL) amyloidosis and transthyretin (TTR) amyloidosis. Although cardiac amyloidosis is thought to be a very rare disease, emerging data suggested that 13% of heart failure patients with preserved ejection fraction and 16-26% of advanced aged patients with severe aortic stenosis may have TTR-CA. Amyloidosis with cardiac involvement shows poor prognosis with a median survival of 6 months in AL-CA and 26-43 months in TTR-CA. Early diagnosis and novel therapeutic options have been shown to significantly improve prognosis. Recent diagnostic techniques such as cardiac MR or nuclear scintigraphy using bone isotopes as well as increasingly wide use of echocardiography, genetic testing, biopsy and histopathological analysis allow the clinicians to make early diagnosis of CA. The aim of this paper is to provide a comprehensive review including etiology, clinical presentation, diagnosis and management of CA and to address recent important advances in noninvasive cardiac imaging techniques and novel therapeutic approaches based on the available data in the literature.

Integration of critical care echo with other noninvasive cardiac imaging techniques

The gradual integration of echocardiography with other noninvasive imaging techniques continues to progress, giving the practicing critical care clinician increasing diagnostic capability. Such capability can be divided into four main areas – coronary artery disease, myocardial pathology, valvular disease, and cardiac function. Coronary artery disease The presence of segmental wall defects on echocardiography alerts the clinician as to a high likelihood of underlying epicardial coronary artery disease (CAD). At the bedside the use of echocardiographic myocardial perfusion techniques can often further differentiate between ischaemic and nonischaemic aetiologies. Coronary computerized Tomographic Angiography (CCTA) over the last decade has moved from being a guide to the presence of CAD, to now offering accurate anatomical assessment, often being used as a first line diagnostic tool.The addition of Fractional Flow Reserve (FFR-CT) now adds a functional assessment of perfusion, reaching an accuracy of that obtained with invasive coronary angiography FFR studies.A noninvasive nuclear medicine alternative is SPECT or Single Photon Emission Computed Tomography which also has high diagnostic capability. Myocardial Pathology When abnormal myocardial appearances are found with echocardiography, it is difficult to be certain of the underlying pathology and historically a myocardial biopsy is considered when seeking to identify presumed inflammatory changes of unknown aetiology. The advent of Cardiac Magnetic Resonance (CMR) assists the physician in the differential diagnosis. The judicious use of T1 mapping, T2 mapping and gadolinium helps differentiate between fibrosis,inflammation and oedema. Valve pathology Although echocardiography remains the major modality is assessing valve function in the critically ill patient, CMR can improve evaluation with prosthetic valves. Myocardial function Echocardiography using Strain have enhance our ability to assess myocardial function. Positron Emission Tomography (PET) using isotopic-labelled substrates offers opportunities to exam metabolic function in the myocardium.It can determine glucose and fatty acid uptake in addition to targeting the mitochondria and angiogenesis. Although challenges arise in the need for a patient to be transferred, information gained may outweigh the risks in some patients. The sophistication of echocardiographic techniques continues to evolve but the wise physician will be cognizant of other noninvasive imaging modalities in an effort to further optimize patient management.

Feature tracking cardiac magnetic resonance imaging: A review of a novel non-invasive cardiac imaging technique.

Cardiovascular disease is a leading cause of morbidity and mortality globally. Early diagnostic markers are gaining popularity for better patient care disease outcomes. There is an increasing interest in noninvasive cardiac imaging biomarkers to diagnose subclinical cardiac disease. Feature tracking cardiac magnetic resonance imaging is a novel post-processing technique that is increasingly being employed to assess global and regional myocardial function. This technique has numerous applications in structural and functional diagnostics. It has been validated in multiple studies, although there is still a long way to go for it to become routine standard of care.

Clinical importance of epicardial adipose tissue.

Different visceral fat compartments have several systemic effects and may play a role in the development of both insulin resistance and cardiovascular diseases. In the last couple of years special attention has been paid to the epicardial adipose tissue (EAT), which can be quantified by non-invasive cardiac imaging techniques. The epicardial fat is a unique fat compartment between the myocardium and the visceral pericardium sharing a common embryologic origin with the visceral fat depot. Epicardial adipose tissue has several specific roles, and its local effects on cardiac function are incorporated in the complex pathomechanism of coronary artery disease. Importantly, EAT may produce several adipocytokines and chemokines that may influence – through paracrine and vasocrine effects – the development and progression of coronary atherosclerosis. Epicardial adipose tissue volume has a relatively strong genetic dependence, similarly to other visceral fat depots. In this article, the anatomical and physiological as well as pathophysiological characteristics of the epicardial fat compartment are reviewed.

Noninvasive Imaging of Human Atrial Activation during Atrial Flutter and Normal Rhythm from Body Surface Potential Maps.

BackgroundKnowledge of atrial electrophysiological properties is crucial for clinical intervention of atrial arrhythmias and the investigation of the underlying mechanism. This study aims to evaluate the feasibility of a novel noninvasive cardiac electrical imaging technique in imaging bi-atrial activation sequences from body surface potential maps (BSPMs).MethodsThe study includes 7 subjects, with 3 atrial flutter patients, and 4 healthy subjects with normal atrial activations. The subject-specific heart-torso geometries were obtained from MRI/CT images. The equivalent current densities were reconstructed from 208-channel BSPMs by solving the inverse problem using individual heart-torso geometry models. The activation times were estimated from the time instant corresponding to the highest peak in the time course of the equivalent current densities. To evaluate the performance, a total of 32 cycles of atrial flutter were analyzed. The imaged activation maps obtained from single beats were compared with the average maps and the activation maps measured from CARTO, by using correlation coefficient (CC) and relative error (RE).ResultsThe cardiac electrical imaging technique is capable of imaging both focal and reentrant activations. The imaged activation maps for normal atrial activations are consistent with findings from isolated human hearts. Activation maps for isthmus-dependent counterclockwise reentry were reconstructed on three patients with typical atrial flutter. The method was capable of imaging macro counterclockwise reentrant loop in the right atrium and showed inter-atria electrical conduction through coronary sinus. The imaged activation sequences obtained from single beats showed good correlation with both the average activation maps (CC = 0.91±0.03, RE = 0.29±0.05) and the clinical endocardial findings using CARTO (CC = 0.70±0.04, RE = 0.42±0.05).ConclusionsThe noninvasive cardiac electrical imaging technique is able to reconstruct complex atrial reentrant activations and focal activation patterns in good consistency with clinical electrophysiological mapping. It offers the potential to assist in radio-frequency ablation of atrial arrhythmia and help defining the underlying arrhythmic mechanism.