The Importance of Serial POCUS Exams - Dual Pathologies in Play.

Serial point of care ultrasound (POCUS) exams are essential to assess acute pericardial effusions which can rapidly evolve into cardiac tamponade. A typical presentation includes dyspnea, tachycardia, and chest pain. Importantly, serial cardiac exams in such high-risk patients can detect other concurrent pathologies. We present an unusual case of a patient who initially presented with an acute circumferential pericardial effusion and upon serial POCUS exams developed an unexpected Takotsubo cardiomyopathy in the setting of cardiac tamponade.

Endocardially Derived Macrophages Are Essential for Valvular Remodeling.

During mammalian embryogenesis, de novo hematopoiesis occurs transiently in multiple anatomical sites including the yolk sac, dorsal aorta, and heart tube. A long-unanswered question is whether these local transient hematopoietic mechanisms are essential for embryonic growth. Here, we show that endocardial hematopoiesis is critical for cardiac valve remodeling as a source of tissue macrophages. Colony formation assay from explanted heart tubes and genetic lineage tracing with the endocardial specific Nfatc1-Cre mouse revealed that hemogenic endocardium is a de novo source of tissue macrophages in the endocardial cushion, the primordium of the cardiac valves. Surface marker characterization, gene expression profiling, and ex vivo phagocytosis assay revealed that the endocardially derived cardiac tissue macrophages play a phagocytic and antigen presenting role. Indeed, genetic ablation of endocardially derived macrophages caused severe valve malformation. Together, these data suggest that transient hemogenic activity in the endocardium is indispensable for the valvular tissue remodeling in the heart.