As coronavirus cases surge across the country, infectious disease and medical experts are developing new theories about the spread of the disease and its manifestations. In Washington state, a gathering of asymptomatic choir singers earlier this month resulted in dozens of cases of COVID-19, including two deaths. Scientists say it was likely passed through the air, refuting earlier studies that say contagion via aerosolized particles is highly unlikely. Meanwhile, cardiologists are warning that some COVID-19 patients have worse cardiac symptoms than respiratory ones, in some cases mimicking a heart attack.