Is it possible to use an oscilloscope as an EKG device?

Yes, it is possible to use an oscilloscope as an EKG device. An electrocardiogram (ECG or EKG) is a simple and important diagnostic tool that measures the electrical activity of the heart over time.
An oscilloscope has the capability to display a wide range of signals – including electrocardiograms! It can measure voltage versus time, which makes it perfect for displaying ECGs. The result may not be as high-resolution or accurate as commercially available ECGs from medical labs, but it can nonetheless provide useful information about your heart's electrical functions.
In order to use an oscilloscope as an EKG device, you will need some additional hardware in addition to the scope itself: electrodes for placing on your skin, amplifiers for boosting signal strength, filters for noise reduction and extraction of relevant data from raw readings, and software for analyzing the data that has been collected.
If you have access to commercial-grade equipment used in medical laboratories – such as multi-channel ECG systems with automatic built-in triggering mechanisms – then you can certainly record and analyze very high resolution data with excellent accuracy; however if all you have is an oscilloscope at hand then there are still plenty of possibilities at your disposal!