To properly rule out a heart attack you would need
a) A twelve-lead EKG - which requires twelve wires to be connected to specific locations on your body
and
b) Blood tests
Therefore for a consumer-grade device to properly rule out a heart attack it would need to be a large EKG machine with multiple connectors as well as a blood test analysis machine. And that's not even considering that proper analysis of an EKG trace requires a trained medical professional, as the automated traces are notoriously unreliable
a) A twelve-lead EKG - which requires twelve wires to be connected to specific locations on your body
and
b) Blood tests
Therefore for a consumer-grade device to properly rule out a heart attack it would need to be a large EKG machine with multiple connectors as well as a blood test analysis machine. And that's not even considering that proper analysis of an EKG trace requires a trained medical professional, as the automated traces are notoriously unreliable