Papillary muscle infarction in relation to left ventricular infarct distribution and transmurality - assessment by delayed enhancement cardiac magnetic resonance imaging

This study used delayed enhancement CMR (DE-CMR) and invasive angiography to evaluate relationships between papillary muscle and left ventricular (LV) chamber wall infarction following ST segment elevation MI (STEMI). Results demonstrate that papillary muscle infarction (PMI) parallels infarct transmurality and contractile dysfunction within the adjacent LV wall

Aortic enlargement in chronic obstructive pulmonary disease (COPD) and emphysema: The Multi-Ethnic Study of Atherosclerosis (MESA) COPD study

Background: The prevalence of abdominal aortic aneurysm is high in chronic obstructive pulmonary disease (COPD) population. Emphysema involves proteolytic destruction of elastic fibers. Therefore, emphysema may also contribute to thoracic aorta dilatation. This study assessed aorta dilation in smokers stratified by presence of COPD, emphysema and airway thickening. Methods: Aorta diameters were measured on 3D magnetic resonance angiography in smokers recruited from the Multi-Ethnic Study of Atherosclerosis (MESA), the Emphysema and Cancer Action Project (EMCAP), and the local community. COPD was defined by standard spirometric criteria; emphysema was measured quantitatively on computed tomography and bronchitis was determined from medical history. Results: Participants (n = 315, age 58–79) included 150 with COPD and 165 without COPD, of whom 56% and 19%, respectively, had emphysema. Subjects in the most severe quartile of emphysematous change showed the largest diameter at all four aorta locations compared to those in the least severe quartiles (all p < 0.001). Comparing subjectswith andwithout COPD, aorta diameters were larger in participantswith severe COPD in ascending and arch (both p < 0.001), and abdominal aorta (p = 0.001). Chronic bronchitis and bronchial wall thickness did not correlate with aorta diameter. In subjects with emphysema, subjects with coexistence of COPD showed larger aorta than those without COPD in ascending (p=0.003), arch (p=0.002), and abdominal aorta (p=0.04). Conclusions: This study showed larger aorta diameter in subjects with COPD and severe emphysema

Electromechanical wave imaging of normal and ischemic hearts in vivo

Abstract-Electromechanical wave imaging (EWI) has recently been introduced as a noninvasive, ultrasound-based imaging modality, which could map the electrical activation of the heart in various echocardiographic planes in mice, dogs, and humans in vivo. By acquiring radio-frequency (RF) frames at very high frame rates (390-520 Hz), the onset of small, localized, transient deformations resulting from the electrical activation of the heart, i.e., generating the electromechanical wave (EMW), can be mapped. The correlation between the EMW and the electrical activation speed and pacing scheme has previously been reported. In this study, we pursue the development of EWI using both displacements and strains and analysis of the EMW properties in dogs in vivo for early detection of ischemia. EWI was performed in normal and ischemic open-chest dogs during sinus rhythm. Ischemia of increasing severity was obtained by gradually obstructing the left-anterior descending (LAD) coronary artery flow. We also introduce the novel method of motion-matching that achieves the reconstruction of the full EWI ciné-loop at very high frame rates even when the ECG may be irregular or unavailable. Incremental displacements were previously used by our group to map the EMW. This paper focuses on the associated incremental strains, which facilitate the interpretation of the EMW by relating it directly to contraction. Moreover, we define the onset of the EMW as the time, at which the incremental strains change sign after the onset of the QRS complex of the ECG. Based on this definition, isochronal representations of the EMW were generated using a semi-automated method. The isochronal representation of the EMW during sinus rhythm was reproducible and shown similar to electrical activation maps previously reported in the literature. After segmentation using a contour-tracking method, the twoand four-chamber views were imaged and displayed in bi-plane views, allowing a 3-D interpretation of the EMW. EWI was shown to be sensitive to the presence of intermediate ischemia. EWI localized the ischemic region when the LAD flow was obstructed at 60% and beyond and was capable of mapping the increase of the ischemic region size as the LAD occlusion level increased. In conclusion, the activation maps and wave patterns obtained with EWI were similar to the electrical equivalents previously reported in the literature. Moreover, EWI was found to be sensitive enough to detect and map intermediate ischemia. Those that EWI could be used to assess the conduction properties of the myocardium, and detect its ischemic onset and disease progression entirely noninvasively. Index Terms-Electrical mapping, electromechanical wave imaging, high framerate echocardiography, ischemia, radio-frequency speckle-tracking

Pulse Wave Imaging in Murine Abdominal Aortas A Feasibility Study

Abstract-One of the most crucial aspects of abdominal aortic aneurysm (AAA) diagnosis lies in the earl

Autoimmunity against the second extracellular loop of beta1-adrenergic receptors induces early afterdepolarization and decreases in K-channel density in rabbits

AbstractObjectivesWe sought to define the electrophysiologic property of the rabbit heart associated with autoimmunity against the second extracellular loop of the beta1-adrenergic receptor.BackgroundSudden death of patients with cardiomyopathy, probably due to lethal ventricular arrhythmias, can be predicted by the presence of autoantibodies against the second extracellular loop of the beta1-adrenergic receptor.MethodsRabbits were immunized by repetitive subcutaneous administration of a synthetic peptide corresponding to the second extracellular loop of beta1-adrenergic receptors (beta group; n = 30) for a mean of 4.2 months. Control rabbits received only vehicle (control group; n = 30).ResultsOne of the rabbits in the beta group died suddenly during the observation period, but none of the control animals died. The prevalence of sustained ventricular tachycardia was significantly higher in the beta group (beta: 4 of 27 vs. control: 0 of 30), and a standard microelectrode experiment revealed prolongation of the action potential duration (APD) in the right ventricular papillary muscle (beta: 156 ± 5 ms vs. control: 131 ± 4 ms; p < 0.05). Early afterdepolarization (EAD) was observed in one rabbit in the beta group (1 of 26), but not in any animals in the control group (0 of 17). A dose of 100 nmol/l of E-4031 induced EAD in the beta group (10 of 10), but not in the control group, except for one rabbit (1 of 10). The whole-cell, patch-clamp experiment on left ventricular M cells showed significant decreases in transient outward current (Ito1) (−43%) and slowly activated delayed rectifier current (IKs) densities (−33%), whereas the inward-rectifying K current (IK1) and rapidly activated delayed rectifier current (IKr) densities remained unchanged.ConclusionsLong-term immunization against the second extracellular loop of the beta1-adrenergic receptor caused EAD and APD prolongation and decreased the K-channel density, suggesting that an arrhythmic substrate via autoimmune mechanisms is present in cardiomyopathic patients who have autoantibodies directed against the receptors

Echocardiography Abnormal Findings and Laboratory Operations during the COVID-19 Pandemic at a High Volume Center in New York City

(1) Background: This study sought to explore how the novel coronavirus (COVID-19) pandemic affected the echocardiography (TTE) laboratory operations at a high volume medical center in New York City. Changes in cardiac imaging study volume, turn-around time, and abnormal findings were analyzed and compared to a pre-pandemic period. (2) Methods: Volume of all cardiac imaging studies and TTE reports between 11 March 2020 to 5 May 2020 and the same calendar period in 2019 were retrospectively identified and compared. (3) Results: During the pandemic, our center experienced a 46.72% reduction in TTEs, 82.47% reduction in transesophageal echocardiograms, 83.16% reduction in stress echo, 70.32% reduction in nuclear tests, 46.25% reduction in calcium score, 73.91% reduction in coronary computed tomography angiography, and 87.23% reduction in cardiac magnetic resonance imaging. TTE findings were overall similar between 2020 and 2019 (all p &ge; 0.05), except for a significantly higher right ventricular systolic pressure in 2020 (39.8 &plusmn; 14.2 vs. 34.6 &plusmn; 11.2 mmHg, p = 0.012). (4) Conclusions: Despite encountering an influx of critically ill patients, our hospital center experienced a reduction in the number of cardiac imaging studies, which likely represents a change in both patient mindset and physician management approach