To answer the OPs questions.
You probably meant if the patient is experiencing symptoms of a heart attack, (as this can only be diagnosed either by paramedics or in a hospital).
I would say no, people usually care about themselves. When they believe they are experiencing what might be a health related emergency they usually seek help from whoever is better equipped and trained.
A patient experiencing signs or symptoms of what can possibly be a cardiac event really has three options to get diagnosis and treatment (in NYC), 911, Hatzalah or go by car. any other bridge service will help with measuring your blood pressure and even call 911 for you. Yet what this patient really requires is early diagnostics and transport.