Less commonly, sinus arrhythmia may indicate an underlying medical problem, like heart disease or heart block. The heart's normal sinus rhythm is created by electrical signals that spread ...

A total of 663 unselected 7-, 10- and 14-year-old school children were examined for both ultrasound and X-ray maxillary sinus findings. Ultrasound and X-ray findings were normal in 84.5% and 83.9% ...