In recent times, dealing with deaths associated with cardiovascular diseases (CVD) has been one of the most challenging issues. The usage of mobile phones and portable Electrocardiogram (ECG) acquisition devices can mitigate the risks associated with CVD by providing faster patient diagnosis and patient care. The existing technologies entail delay in patient authentication and diagnosis. However, for the cardiologists minimizing the delay between a possible CVD symptom and patient care is crucial, as this has a proven impact in the longevity of the patient. Therefore, every seconds counts in terms of patient authentication and diagnosis. In this paper, we introduce the concept of Cardioid based patient authentication and diagnosis. According to our experimentations, the authentication time can be reduced from 30.64 s (manual authentication in novice mobile user) to 0.4398 s (automated authentication). Our ECG based patient authentication mechanism is up to 4878 times faster than conventional biometrics like, face recognition. The diagnosis time could be improved from several minutes to less than 0.5 s (cardioid display on a single screen). Therefore, with our presented mission critical alerting mechanism on wireless devices, minute's worth of tasks can be reduced to second's, without compromising the accuracy of authentication and quality of diagnosis. Copyright © 2011 John Wiley & Sons, Ltd.