Quite an in-depth review article that looks at the varied usages for ultrasound in the general practice setting from the Journal of Family Practice, Canada
Over five pages the article covers AAA screening, obstetric dating, guiding procedures, quick look cardiac assessment. The article also provides a good precis of relevant evidence for non-sonographer/radiologist ultrasound use.
Next is a research study from the British Journal of Cardiology. To be clear the person doing the scanning was not a general practitioner, they were a trained sonographer however the setting was in general practice – assessing what findings a quick look cardiac scan can detect.
Of 163 scans, they were normal in 80 (49%), mildly abnormal in 67 (41%) and significantly abnormal in 16 (10%).