TRE reduced MI-induced cardiac remodeling and dysfunction through activation of autophagy.

Background: We investigate whether deep learning (DL) neural networks can reduce erroneous human "judgment calls" on bedside echocardiograms and help distinguish Takotsubo syndrome (TTS) from anterior wall ST segment elevation myocardial infarction (STEMI). Methods: We developed a single-channel (DCNN[2D SCI]), a multi-channel (DCNN[2D MCI]), and a 3-dimensional (DCNN[2D+t]) deep convolution neural network, and a recurrent neural network (RNN) based on 17,280 still-frame images and 540 videos from 2-dimensional echocardiograms in 10 years (1 January 2008 to 1 January 2018) retrospective cohort in University of Iowa (UI) and eight other medical centers. Echocardiograms from 450 UI patients were randomly divided into training and testing sets for internal training, testing, and model construction. Echocardiograms of 90 patients from the other medical centers were used for external validation to evaluate the model generalizability. A total of 49 board-certified human readers performed human-side classification on the same echocardiography dataset to compare the diagnostic performance and help data visualization. Findings: The DCNN (2D SCI), DCNN (2D MCI), DCNN(2D+t), and RNN models established based on UI dataset for TTS versus STEMI prediction showed mean diagnostic accuracy 73%, 75%, 80%, and 75% respectively, and mean diagnostic accuracy of 74%, 74%, 77%, and 73%, respectively, on the external validation. DCNN(2D+t) (area under the curve [AUC] 0¢787 vs. 0¢699, P = 0¢015) and RNN models (AUC 0¢774 vs. 0¢699, P = 0¢033) outperformed human readers in differentiating TTS and STEMI by reducing human erroneous judgement calls on TTS. Interpretation: Spatio-temporal hybrid DL neural networks reduce erroneous human "judgement calls" in distinguishing TTS from anterior wall STEMI based on bedside echocardiographic videos.

Background The mechanisms by which acute left atrial ischemia (LAI) leads to AF initiation and perpetuation remain unclear. Methods and Results LAI (90-minute ischemia) was obtained in isolated sheep hearts by selectively perfusing microspheres into the left anterior atrial artery. Two CCD cameras and several bipolar electrodes enabled recording from multiple atrial locations: with a dual-camera set-up (Protocol 1, n=10; and 1′, n=4; for bi-atrial or atrio-ventricular camera set-ups respectively), in the presence of propranolol/atropine (1μM) added to the perfusate after LAI (protocol 2, n=3) and after a pre-treatment with glibenclamide 10 μM (protocol 3, n=4). Spontaneous AF occurred in 41.2% (7/17) of the hearts that were in sinus rhythm before LAI. LAI caused APD shortening in both the ischemic (IZ) and non-ischemic (NIZ) zones by 21±8 and 34±13%, respectively (pacing, 5Hz, p<0.05 compared to baseline). Apparent impulse velocity was significantly reduced in the IZ but not in the NIZ (−65±19% and +9±18%, p=0.001 and n.s, respectively). During LAI-related AF, a significant NIZ maximal dominant frequency (DFmax) increase from 7.4±2.5 to 14.0±5.5 Hz; p<0.05, was observed. Glibenclamide, an IKATP channel blocker, averted LAI-related DFmax increase (NIZ: LAI vs Gli, 14.0±5.5 vs. 5.9±1.3 Hz, p<0.05). Interplay between spontaneous focal discharges and rotors, locating at the IZ-NIZ border zone, maintained LAI-related AF. Conclusions LAI leads to an IKATP conductance-dependent APD shortening and spontaneous AF maintained by both spontaneous focal discharges and reentrant circuits locating at the IZ border zone.

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Takotsubo cardiomyopathy is a form of reversible cardiomyopathy. It is usually due to sudden emotional or physical stress. It is associated with excessive sympathetic stimulation and catecholamine release. Patients have a very similar presentation to an acute coronary syndrome with patent coronaries. We present a case of takotsubo cardiomyopathy in a patient who has a history of Sjogren’s disease on a steroid taper.