Maybe we should think of Covid-19 as a heart disease. When SARS-CoV-2 virus was added to human heart cells grown in lab dishes, the long muscle fibers that keep hearts beating were diced into short bits, alarming scientists at the San Francisco-based Gladstone Institutes, especially after they saw a similar phenomenon in heart tissue from Covid-19 patients’ autopsies. Their experiments could potentially explain why some people still feel short of breath after their Covid infections clear and add to worries that survivors may be at risk for future heart failure.