Cardiovascular magnetic resonance detects microvascular dysfunction in a mouse model of hypertrophic cardiomyopathy.

BACKGROUND: Hypertrophic cardiomyopathy (HCM) related myocardial vascular remodelling may lead to the reduction of myocardial blood supply and a subsequent progressive loss of cardiac function. This process has been difficult to observe and thus their connection remains unclear. Here we used non-invasive myocardial blood flow sensitive CMR to show an impairment of resting myocardial perfusion in a mouse model of naturally occurring HCM. METHODS: We used a mouse model (DBA/2 J; D2 mouse strain) that spontaneously carries variants in the two most susceptible HCM genes-Mybpc3 and Myh7 and bears the key features of human HCM. The C57BL/6 J (B6) was used as a reference strain. Mice with either B6 or D2 backgrounds (male: n = 4, female: n = 4) underwent cine-CMR for functional assessment at 9.4 T. Left ventricular (LV) wall thickness was measured in end diastolic phase by cine-CMR. Quantitative myocardial perfusion maps (male: n = 5, female: n = 5 in each group) were acquired from arterial spin labelling (cine ASL-CMR) at rest. Myocardial perfusion values were measured by delineating different regions of interest based on the LV segmentation model in the mid ventricle of the LV myocardium. Directly after the CMR, the mouse hearts were removed for histological assessments to confirm the incidence of myocardial interstitial fibrosis (n = 8 in each group) and small vessel remodelling such as vessel density (n = 6 in each group) and perivascular fibrosis (n = 8 in each group). RESULTS: LV hypertrophy was more pronounced in D2 than in B6 mice (male: D2 LV wall thickness = 1.3 ± 0.1 mm vs B6 LV wall thickness = 1.0 ± 0.0 mm, p < 0.001; female: D2 LV wall thickness = 1.0 ± 0.1 mm vs B6 LV wall thickness = 0.8 ± 0.1 mm, p < 0.01). The resting global myocardial perfusion (myocardial blood flow; MBF) was lower in D2 than in B6 mice (end-diastole: D2 MBFglobal = 7.5 ± 0.6 vs B6 MBFglobal = 9.3 ± 1.6 ml/g/min, p < 0.05; end-systole: D2 MBFglobal = 6.6 ± 0.8 vs B6 MBFglobal = 8.2 ± 2.6 ml/g/min, p < 0.01). This myocardial microvascular dysfunction was observed and associated with a reduction in regional MBF, mainly in the interventricular septal and inferior areas of the myocardium. Immunofluorescence revealed a lower number of vessel densities in D2 than in B6 (D2 capillary = 31.0 ± 3.8% vs B6 capillary = 40.7 ± 4.6%, p < 0.05). Myocardial collagen volume fraction (CVF) was significantly higher in D2 LV versus B6 LV mice (D2 CVF = 3.7 ± 1.4% vs B6 CVF = 1.7 ± 0.7%, p < 0.01). Furthermore, a higher ratio of perivascular fibrosis (PFR) was found in D2 than in B6 mice (D2 PFR = 2.3 ± 1.0%, B6 PFR = 0.8 ± 0.4%, p < 0.01). CONCLUSIONS: Our work describes an imaging marker using cine ASL-CMR with a potential to monitor vascular and myocardial remodelling in HCM.

Features on cardiac magnetic resonance imaging and accuracy of echocardiographic findings for diagnosing constrictive pericarditis.

Constrictive pericarditis is a rare disease with a difficult diagnosis. Cardiac magnetic resonance (CMR) imaging data of Aga Khan University Hospital from January 2011 to March 2020 was retrospectively reviewed and patients with the diagnosis of constrictive pericarditis were included. A total of 22 patients were included with the mean age of 46±16 years and majority 17(77%) were male. The most common findings on transthoracic echo were significant respiratory variation in mitral and tricuspid inflow velocities in 20(91%), and septal annular e'>9 in 10 (86%). The most common finding on CMR was respiratory septal shift in 22(100%), followed by septal bounce in 21(95%) and thickened pericardium in 18(82%). Nearly two-third of the patients, 15(70%) were considered for pericardiectomy but it was deferred in 5 patients due to high surgical risk. Ten patients underwent pericardiectomy, with no mortality on a mean follow up of 4±2 years.

Clinical features, cardiac magnetic resonance imaging findings and outcome of patients with suspected myocarditis.

Myocarditis is largely underdiagnosed due to subclinical symptoms and non-availability of diagnostic techniques necessitating high index of suspicion and early disease identification. This study aimed to assess the clinical presentation, cardiac magnetic resonance (CMR) imaging findings and prognosis of these patients. After reviewing the CMR data of Aga Khan University Hospital from January 2011 to December 2019, a total of 24 patients were included in the study with the confirmed diagnosis of myocarditis on CMR. Mean age was 33.4±15 years with the majority (58%) being male. Dyspnoea was the commonest symptom seen in 15(62%) cases followed by chest pain in 13 (54%). On echocardiogram, 15 (62.5%) cases showed LV dysfunction. Common CMR findings were late gadolinium enhancement in 18 (75%) and bright T2 signals in 11 (45%) patients. With a mean follow-up of 3.6±2 years, one patient died of non-cardiac cause. Nine out of 14 patients (for whom repeat echocardiogram was done) had resolution of LV dysfunction suggesting favourable prognosis.

Mechanisms of left ventricular systolic dysfunction in light chain amyloidosis: a multiparametric cardiac MRI study.

Background: Cardiac systolic dysfunction is a poor prognostic marker in light-chain (AL) cardiomyopathy, a primary interstitial disorder; however, its pathogenesis is poorly understood. Purpose: This study aims to analyze the effects of extracellular volume (ECV) expansion, a surrogate marker of amyloid burden on myocardial blood flow (MBF), myocardial work efficiency (MWE), and left ventricular (LV) systolic dysfunction in AL amyloidosis. Methods: Subjects with biopsy-proven AL amyloidosis were prospectively enrolled (April 2016-June 2021; Clinicaltrials.gov ID NCT02641145) and underwent cardiac magnetic resonance imaging (MRI) to quantify rest MBF by perfusion imaging, LV ejection fraction (LVEF) by cine MRI, and ECV by pre- and post-contrast T1 mapping. The MWE was estimated as external cardiac work from the stroke volume and mean arterial pressure normalized to the LV myocardial mass. Results: Rest MBF in 92 subjects (62 ± 8 years, 52 men) with AL amyloidosis averaged 0.87 ± 0.21 ml/min/g and correlated with MWE (r = 0.42; p < 0.001). Rest MBF was similarly low in subjects with sustained hematologic remission after successful AL amyloidosis therapy (n = 21), as in those with recently diagnosed AL amyloidosis. Both MBF and MWE decreased by ECV tertile (p < 0.01 for linear trends). The association of ECV with MWE comprised a direct effect (84% of the total effect; p < 0.001) on MWE from adverse interstitial remodeling assessed by ECV and an indirect effect (16% of the total effect; p < 0.001) mediated by MBF. There was a significant base-to-apex gradient of rest MBF in subjects with higher amyloid burden. Conclusions: In AL amyloidosis, both MBF and MWE decrease as cardiac amyloid burden and ECV expansion increase. Both structural and vascular changes from ECV expansion and myocardial amyloid burden appear to contribute to lower MWE.

Wideband radiofrequency pulse sequence for evaluation of myocardial scar in patients with cardiac implantable devices.

Background: Cardiac magnetic resonance is a useful clinical tool to identify late gadolinium enhancement in heart failure patients with implantable electronic devices. Identification of LGE in patients with CIED is limited by artifact, which can be improved with a wide band radiofrequency pulse sequence. Objective: The authors hypothesize that image quality of LGE images produced using wide-band pulse sequence in patients with devices is comparable to image quality produced using standard LGE sequences in patients without devices. Methods: Two independent readers reviewed LGE images of 16 patients with CIED and 7 patients without intracardiac devices to assess for image quality, device-related artifact, and presence of LGE using the American Society of Echocardiography/American Heart Association 17 segment model of the heart on a 4-point Likert scale. The mean and standard deviation for image quality and artifact rating were determined. Inter-observer reliability was determined by calculating Cohen's kappa coefficient. Statistical significance was determined by T-test as a p {less than or equal to} 0.05 with a 95% confidence interval. Results: All patients underwent CMR without any adverse events. Overall IQ of WB LGE images was significantly better in patients with devices compared to standard LGE in patients without devices (p = 0.001) with reduction in overall artifact rating (p = 0.05). Conclusion: Our study suggests wide-band pulse sequence for LGE can be applied safely to heart failure patients with devices in detection of LV myocardial scar while maintaining image quality, reducing artifact, and following routine imaging protocol after intravenous gadolinium contrast administration.

Acute Cardiomyopathy in a Prisoner on a Hunger Strike.

Chronic starvation and its associated metabolic derangements are known to have dangerous cardiovascular implications in the long term, but less is known about the cardiovascular consequences of acute starvation, such as in the context of a hunger strike. This case describes a patient who presented with signs and symptoms of acute coronary syndrome which began two weeks into a hunger strike and was ultimately found to have stress cardiomyopathy with complete resolution on subsequent imaging.

Overlapping Phenotypes of Alcoholic Cardiomyopathy and Left Ventricular Non-compaction: A Case Report and Discussion of Converging Cardiomyopathies.

Left ventricular non-compaction cardiomyopathy, often known as LVNC, is a form of congenital cardiomyopathy that is extremely uncommon. It is a condition that may be identified by an elevated number of endomyocardial trabeculations as well as an increase in their prominence. Alcoholic cardiomyopathy, also known as ACM, is a non-ischemic form of dilated cardiomyopathy that is characterized by contractile failure and an enlargement of the heart ventricles. It is not entirely known whether or not there is a clinically significant overlap in phenotypic characteristics between the two illnesses. We report a patient who had previously been diagnosed with ACM and who had cardiac MRI results that fit the criteria for both LVNC and ACM.

Tissue characterization of benign cardiac tumors by cardiac magnetic resonance imaging, a review of core imaging protocol and benign cardiac tumors.

Generally, cardiac masses are initially suspected on routine echocardiography. Cardiac magnetic resonance (CMR) imaging is further performed to differentiate tumors from pseudo-tumors and to characterize the cardiac masses based on their appearance on T1/T2-weighted images, detection of perfusion and demonstration of gadolinium-based contrast agent uptake on early and late gadolinium enhancement images. Further evaluation of cardiac masses by CMR is critical because unnecessary surgery can be avoided by better tissue characterization. Different cardiac tissues have different T1 and T2 relaxation times, principally owing to different internal biochemical environments surrounding the protons. In CMR, the signal intensity from a particular tissue depends on its T1 and T2 relaxation times and its proton density. CMR uses this principle to differentiate between various tissue types by weighting images based on their T1 or T2 relaxation times. Generally, tumor cells are larger, edematous, and have associated inflammatory reactions. Higher free water content of the neoplastic cells and other changes in tissue composition lead to prolonged T1/T2 relaxation times and thus an inherent contrast between tumors and normal tissue exists. Overall, these biochemical changes create an environment where different cardiac masses produce different signal intensity on their T1- weighted and T2- weighted images that help to discriminate between them. In this review article, we have provided a detailed description of the core CMR imaging protocol for evaluation of cardiac masses. We have also discussed the basic features of benign cardiac tumors as well as the role of CMR in evaluation and further tissue characterization of these tumors.

Sex differences in contributors to coronary microvascular dysfunction.

Background: Coronary microvascular dysfunction (CMD) has differences in prevalence and presentation between women and men; however, we have limited understanding about underlying contributors to sex differences in CMD. Myocardial perfusion reserve index (MPRI), as semi-quantitative measure of myocardial perfusion derived from cardiac magnetic resonance (CMR) imaging has been validated as a measure of CMD. We sought to understand the sex differences in the relations between the MPRI and traditional measures of cardiovascular disease by CMR. Methods: A retrospective analysis of a single-center cohort of patients receiving clinical stress CMR from 2015 to 2022 was performed. Patients with calculated MPRI and no visible perfusion defects consistent with obstructive epicardial coronary disease were included. We compared associations between MPRI versus traditional cardiovascular risk factors and markers of cardiac structure/function in sex-stratified populations using univariable and multivariable regression models. Results: A total of 229 patients [193 female, 36 male, median age 57 (47-67) years] were included in the analysis. In the female population, no traditional cardiovascular risk factors were associated with MPRI, whereas in the male population, diabetes (ß: -0.80, p = 0.03) and hyperlipidemia (ß: -0.76, p = 0.006) were both associated with reduced MPRI in multivariable models. Multivariable models revealed significant associations between reduced MPRI and increased ascending aortic diameter (ß: -0.42, p = 0.005) and T1 times (ß: -0.0056, p = 0.03) in the male population, and increased T1 times (ß: -0.0037, p = 0.006) and LVMI (ß: -0.022, p = 0.0003) in the female population. Conclusion: The findings suggest different underlying pathophysiology of CMD in men versus women, with lower MPRI in male patients fitting a more "traditional" atherosclerotic profile.

Metastatic Renal Cell Carcinoma Presenting as an Intracardiac Tumour Without Involving the Inferior Vena Cava.

Renal cell carcinoma (RCC) is an aggressive tumour, with 25% of the cases presenting with distant metastases at the time of diagnosis. Approximately 33% of the patients with RCC eventually develop metastatic spread. RCC can metastasize to various sites including the lung, liver, bone, brain, adrenal gland, and more. Cardiac metastasis is rare in RCC, but even rarer in the absence of inferior vena cava (IVC) involvement. This case report presents a 60-year-old male patient who was referred by his general practitioner due to breathing difficulties. An initial echocardiogram revealed a right ventricular outflow tract obstruction caused by a mass. A subsequent cardiac MRI showed a right ventricular mass with features suggestive of a metastatic spread. A CT scan of the thorax, abdomen and pelvis was done to ascertain the primary tumour which revealed RCC, without involving the IVC. Due to the presence of metastases, advanced disease, and heavy tumour burden, the multidisciplinary team concluded that there were almost negligible treatment options available at that stage and recommended the best supportive care and community hospice support. The patient was discharged once his symptoms improved, as per his request, and he passed away peacefully at home within a month. This case highlights the very rare occurrence of cardiac metastasis of RCC without IVC involvement. It also illustrates the approach and investigations involved in the evaluation of complex cardiac masses.

Cardiac geometry, as assessed by cardiac magnetic resonance, can differentiate subtypes of chronic thromboembolic pulmonary vascular disease.

Background: Ventricular septal flattening reflects RV pressure overload in pulmonary arterial hypertension. Eccentricity index (EI) and pulmonary artery distensibility (PAD) correlate with pulmonary artery pressure. We assessed the utility of these using cardiac magnetic resonance (CMR) to assess for pulmonary hypertension (PH) in patients with chronic thromboembolic disease. This may allow non-invasive differentiation between patients who have chronic thromboembolic pulmonary hypertension (CTEPH) and those with pulmonary vascular obstructions without PH at rest, known as chronic thromboembolic pulmonary disease (CTEPD). Methods: Twenty patients without resting pulmonary hypertension, including ten with chronic thromboembolic disease, and thirty patients with CTEPH were identified from a database at the Scottish Pulmonary Vascular Unit. CMR and right heart catheter had been performed within 96 h of each other. Short-axis views at the level of papillary muscles were used to assess the EI at end-systole and diastole. Pulmonary artery distensibility was calculated using velocity-encoded images attained perpendicular to the main trunk. Results: Eccentricity index at end-systole and end-diastole were higher in CTEPH compared to controls (1.3 ± 0.5 vs. 1.0 ± 0.01; p ≤ 0.01 and (1.22 ± 0.2 vs. 0.98 ± 0.01; p ≤ 0.01, respectively) and compared to those with CTED. PAD was significantly lower in CTEPH compared to controls (0.13 ± 0.1 vs. 0.46 ± 0.23; p ≤ 0.01) and compared to CTED. End-systolic EI and end-diastolic EI correlated with pulmonary vascular hemodynamic indices and exercise variables, including mean pulmonary arterial pressure (R0.74 and 0.75, respectively), cardiac output (R-value -0.4 and -0.4, respectively) NTproBNP (R-value 0.3 and 0.3, respectively) and 6-min walk distance (R-value -0.7 and -0.8 respectively). Pulmonary artery distensibility also correlated with 6-min walk distance (R-value 0.8). Conclusion: Eccentricity index and pulmonary artery distensibility can detect the presence of pulmonary hypertension in chronic thromboembolic disease and differentiate between CTEPH and CTED subgroups. These measures support the use of non-invasive tests including CMR for the detection pulmonary hypertension and may reduce the requirement for right heart catheterization.

Simultaneous multi-parametric acquisition and reconstruction techniques in cardiac magnetic resonance imaging: Basic concepts and status of clinical development.

Simultaneous multi-parametric acquisition and reconstruction techniques (SMART) are gaining attention for their potential to overcome some of cardiovascular magnetic resonance imaging's (CMR) clinical limitations. The major advantages of SMART lie within their ability to simultaneously capture multiple "features" such as cardiac motion, respiratory motion, T1/T2 relaxation. This review aims to summarize the overarching theory of SMART, describing key concepts that many of these techniques share to produce co-registered, high quality CMR images in less time and with less requirements for specialized personnel. Further, this review provides an overview of the recent developments in the field of SMART by describing how they work, the parameters they can acquire, their status of clinical testing and validation, and by providing examples for how their use can improve the current state of clinical CMR workflows. Many of the SMART are in early phases of development and testing, thus larger scale, controlled trials are needed to evaluate their use in clinical setting and with different cardiac pathologies.

Cardiovascular Imaging in Pregnancy: Valvulopathy, Hypertrophic Cardiomyopathy, and Aortopathy.

Pregnancy is associated with profound hemodynamic changes that are particularly impactful in patients with underlying cardiovascular disease. Management of pregnant women with cardiovascular disease requires careful evaluation that considers the well-being of both the woman and the developing fetus. Clinical assessment begins before pregnancy and continues throughout gestation into the post-partum period and is supplemented by cardiac imaging. This review discusses the role of imaging, specifically echocardiography, cardiac MRI, and cardiac CT, in pregnant women with valvular diseases, hypertrophic cardiomyopathy, and aortic pathology.

MRI Feature Tracking Strain in Pulmonary Hypertension: Utility of Combined Left Atrial Volumetric and Deformation Assessment in Distinguishing Post- From Pre-capillary Physiology.

Aims: Pulmonary hypertension (PH) is dichotomized into pre- and post-capillary physiology by invasive catheterization. Imaging, particularly strain assessment, may aid in classification and be helpful with ambiguous hemodynamics. We sought to define cardiac MRI (CMR) feature tracking biatrial peak reservoir and biventricular peak systolic strain in pre- and post-capillary PH and examine the performance of peak left atrial strain in distinguishing the 2 groups compared to TTE. Methods and Results: Retrospective cross-sectional study from 1 Jan 2015 to 31 Dec 2020; 48 patients (22 pre- and 26 post-capillary) were included with contemporaneous TTE, CMR and catheterization. Mean pulmonary artery pressures were higher in the pre-capillary cohort (55 ± 14 vs. 42 ± 9 mmHg; p < 0.001) as was pulmonary vascular resistance (median 11.7 vs. 3.7 WU; p < 0.001). Post-capillary patients had significantly larger left atria (60 ± 22 vs. 25 ± 9 ml/m2; p < 0.001). There was no difference in right atrial volumes between groups (60 ± 21 vs. 61 ± 29 ml/m2; p = 0.694), however peak RA strain was lower in post-capillary PH patients (8.9 ± 5.5 vs. 18.8 ± 7.0%; p < 0.001). In the post-capillary group, there was commensurately severe peak strain impairment in both atria (LA strain 9.0 ± 5.8%, RA strain 8.9 ± 5.5%). CMR LAVi and peak LA strain had a multivariate AUC of 0.98 (95% CI 0.89-1.00; p < 0.001) for post-capillary PH diagnosis which was superior to TTE. Conclusion: CMR volumetric and deformation assessment of the left atrium can highly accurately distinguish post- from pre-capillary PH.

Baseline 4D Flow-Derived in vivo Hemodynamic Parameters Stratify Descending Aortic Dissection Patients With Enlarging Aortas.

Purpose: The purpose of our study was to assess the value of true lumen and false lumen hemodynamics compared to aortic morphological measurements for predicting adverse-aorta related outcomes (AARO) and aortic growth in patients with type B aortic dissection (TBAD). Materials and Methods: Using an IRB approved protocol, we retrospectively identified patients with descending aorta (DAo) dissection at a large tertiary center. Inclusion criteria includes known TBAD with ≥ 6 months of clinical follow-up after initial presentation for TBAD or after ascending aorta intervention for patients with repaired type A dissection with residual type B aortic dissection (rTAAD). Patients with prior descending aorta intervention were excluded. The FL and TL of each patient were manually segmented from 4D flow MRI data, and 3D parametric maps of aortic hemodynamics were generated. Groups were divided based on (1) presence vs. absence of AARO and (2) growth rate ≥ vs. < 3 mm/year. True and false lumen kinetic energy (KE), stasis, peak velocity (PV), reverse/forward flow (RF/FF), FL to TL KE ratio, as well as index aortic diameter were compared between groups using the Mann-Whitney U or independent t-test. Results: A total of n = 51 patients (age: 58.4 ± 15.0 years, M/F: 31/20) were included for analysis of AARO. This group contained n = 26 patients with TBAD and n = 25 patients with rTAAD. In the overall cohort, AARO patients had larger baseline diameters, lower FL-RF, FL stasis, TL-KE, TL-FF and TL-PV. Among patients with de novo TBAD, those with AAROs had larger baseline diameter, lower FL stasis and TL-PV. In both the overall cohort and in the subgroup of de novo TBAD, subjects with aortic growth ≥ 3mm/year, patients had a higher KE ratio. Conclusion: Our study suggests that 4D flow MRI is a promising tool for TBAD evaluation that can provide information beyond traditional MRA or CTA. 4D flow has the potential to become an integral aspect of TBAD work-up, as hemodynamic assessment may allow earlier identification of at-risk patients who could benefit from earlier intervention.

Current State and Future Directions of Multimodality Imaging in Cardiac Sarcoidosis.

Cardiac sarcoidosis (CS) is an increasingly recognized cause of heart failure and arrhythmia. Historically challenging to identify, particularly in the absence of extracardiac sarcoidosis, diagnosis of CS has improved with advancements in cardiac imaging. Recognition as well as management may require interpretation of multiple imaging modalities. Echocardiography may serve as an initial screening study for cardiac involvement in patients with systemic sarcoidosis. Cardiac magnetic resonance imaging (CMR) provides information on diagnosis as well as risk stratification, particularly for ventricular arrhythmia in the setting of late gadolinium enhancement. More recently, 18F-fluorodeoxyglucose position emission tomography (FDG-PET) has assumed a valuable role in the diagnosis and longitudinal management of patients with CS, allowing for the assessment of response to treatment. Hybrid FDG-PET/CT may also be used in the evaluation of extracardiac inflammation, permitting the identification of biopsy sites for diagnostic confirmation. Herein we examine the approach to diagnosis and management of CS using multimodality imaging via a case-based review.

Characterization of the interatrial septum by high-field cardiac MRI: a comparison with multi-slice computed tomography.

BACKGROUND: Assessment of the interatrial septum (IAS) has become an attractive area of interest for a variety of important interventional procedures. Newer imaging modalities like multi-slice computed tomography (MSCT) and cardiac MRI (CMR) can provide higher resolution and wider field of view than echocardiography. Moreover, high-field (3-Tesla) CMR can even enhance spatial and temporal resolution. The characteristics of the interatrial septum were retrospectively studied in 371 consecutive subjects (201 men, 31-73 years old) in whom MSCT was performed primarily for non-invasive evaluation of the coronary arteries. All subjects underwent both MSCT and MRI scans within 0-30 day's interval. A 3D volume covering the whole heart was acquired across the heart with and without contrast enhancement. Also, patients underwent cardiac MSCT examinations using 64-row MSCT scanners. RESULTS: The mean scan time of MSCT was 10.4 ± 2.8 s and 9.7 ± 2.9 min for CMR. The mean length of IAS by CMR and CT was 39.65 ± 4.6 mm and 39.28 ± 4.7 mm, respectively. The mean maximal thickness of IAS by CMR and CT was 3.1 ± 0.97 mm and 3.15 ± 0.95 mm, respectively. The mean thickness of fossa ovalis by CMR and CT was 1.04 ± 0.36 mm and 1.04 ± 0.44 mm, respectively. The mean length of fossa ovalis by CMR and CT was 12.8 ± 3.7 mm and 12.8 ± 3.5 mm, respectively. Finally, the mean angle of IAS by CMR and CT was identical (155 ± 9.2°). Measurements of various morphological features of IAS showed no statistically significant difference between CMR and CT, with an excellent correlation and close relationship regarding IAS length, maximal IAS thickness, fossa ovalis thickness, fossa ovalis length, and IAS angle (r = 0.98, 0.98, 0.95, 0.96, and 0.92, respectively). CONCLUSION: Whole-heart 3D acquisition at 3-T MRI using a free-breathing technique provides a valuable non-invasive imaging tool for excellent assessment of the interatrial septum-as compared to MSCT-that may have significant clinical implication for diagnostic purposes and therapeutic interventional procedures, as it may facilitate planning, improve outcome, and shorten its duration.

Artificial intelligence in pediatric and adult congenital cardiac MRI: an unmet clinical need.

Cardiac MRI (CMR) allows non-invasive, non-ionizing assessment of cardiac function and anatomy in patients with congenital heart disease (CHD). The utility of CMR as a non-invasive imaging tool for evaluation of CHD have been growing exponentially over the past decade. The algorithms based on artificial intelligence (AI), and in particular, deep learning, have rapidly become a methodology of choice for analyzing CMR. A wide range of applications for AI have been developed to tackle challenges in various aspects of CMR, and significant advances have also been made from image acquisition to image analysis and diagnosis. We include an overview of AI definitions, different architectures, and details on well-known methods. This paper reviews the major deep learning concepts used for analyses of patients with CHD. In the end, we have summarized a list of open challenges and concerns to be considered for future studies.

Primary PCI versus pharmacoinvasive strategy for ST elevation myocardial infarction.

BACKGROUND: The rationale for pharmacoinvasive strategy is that many patients have a persistent reduction in flow in the infarct-related artery. The aim of the present study is to assess safety and efficacy of pharmacoinvasive strategy using streptokinase compared to primary PCI and ischemia driven PCI on degree of myocardial salvage and outcomes. METHODS AND RESULTS: Sixty patients with 1st attack of acute STEMI within 12 h were randomized to 4 groups: primary PCI for patients presented to PPCI-capable centers (group I), transfer to PCI if presented to non-PCI capable center (group II), pharmacoinvasive strategy "Streptokinase followed by PCI within 3-24 h" (group III) and fibrinolytic followed by ischemia driven PCI (group IV). The primary endpoint is the infarction size and microvascular obstruction (MVO) measured by cardiac MRI (CMR) 3-5 days post-MI. Pharmacoinvasive strategy led to a significant reduction in infarction size, MVO and major adverse cardiac and cerebrovascular event (MACCE) compared to group IV but minor bleeding was significantly higher compared to other groups. CONCLUSIONS: Pharmacoinvasive strategy resulted in effective reperfusion and smaller infarction size in patients with early STEMI who could not undergo primary PCI within 2 h after the first medical contact. This can provide a wide time window for PCI when the application of primary PCI within the optimal time limit is not possible. However, it was associated with a slightly increased risk of minor bleeding.