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A 67-year-old man with inferior wall ST-segment elevation myocardial infarction underwent Impella-assisted percutaneous coronary intervention complicated by unilateral left-sided pulmonary edema and cardiogenic shock due to severe mitral valve regurgitation. Surgery was deferred due to hemodynamic instability and a high risk of mortality, so he underwent a MitraClip procedure. Mitral regurgitation (MR) is a catastrophic mechanical complication of myocardial infarction that leads to the development of pulmonary edema, cardiogenic shock, and death. After the procedure, the patient significantly reduces MR with a resolution of pulmonary edema. Acute MR can rarely present as a unilateral left-sided pulmonary edema delaying diagnosis and treatment. Transcatheter edge-to-edge repair can be a safe alternative for patients who are at high risk for surgery. [ABSTRACT FROM AUTHOR]

Takotsubo cardiomyopathy is a type of non-ischemic cardiomyopathy that usually appears after a stressful event or in a woman and is rarely seen after pacemaker implantation (PMI). Herein, we present the case of a 65-year-old man with PMI because of a 2:1 atrioventricular nodal block who had a syncopal episode later in the day of the procedure. Echocardiography showed septal and apical hypokinesis with reduced ejection fraction suggestive of takotsubo cardiomyopathy. Before PMI, echocardiography showed normal left ventricular function with no wall-motion abnormality. Coronary angiography showed no coronary artery stenosis. The patient was seen again in the clinic 1 month later, and repeat echocardiography showed improvement of ejection fraction to 55% with no wall-motion abnormality. Generally, the complication rate after PMI is very low and includes infection, hematoma, lead dislocation, or allergic reaction at the site. The clinicians must be aware of potentially rare complications that can occur after PMI, such as takotsubo cardiomyopathy. [ABSTRACT FROM AUTHOR]

COVID-19 pneumonia has several complications, such as acute respiratory distress syndrome, septic shock, myocarditis, pulmonary embolism, and thromboembolic stroke. We present a case of a 71-year-old woman who was diagnosed with COVID-19 pneumonia and was found to have a pneumothorax, spontaneous pneumomediastinum (SPM), and subcutaneous emphysema without a history of lung disease. The pathophysiology of SPM and subcutaneous emphysema is likely caused by rupture of the alveolar membrane due to direct damage by COVID-19 infection and frequent cough-induced barotrauma. [ABSTRACT FROM AUTHOR]

We propose a robust design for digital feedback of the channel impulse response in a time-reversal ultrawideband communication system. The proposed scheme employs channel optimized vector quantization to reduce distortion that occurs due to channel noise on the feedback link. Utilizing experimental channel measurements in a typical indoor environment, we indicate the robustness of the proposed strategy by showing that the scheme's performance remains resilient under channel mismatch conditions that arise due to the combined effect of quantization, feedback delay, and noise on the feedback channel. [ABSTRACT FROM PUBLISHER]