A method comprises monitoring a heart rate, a respiration rate and an activity level of a patient, comparing the monitored heart rate, respiration rate and activity level to a predetermined threshold zone which is a function of heart rate, respiration rate and activity level, determining the patient is experiencing worsening heart failure when the monitored heart rate, respiration rate and activity level are outside the predetermined threshold zone and after determining the patient is experiencing worsening heart failure when the monitored heart rate, respiration rate and activity level are outside the predetermined threshold zone, issuing an alert to indicate that the patient is experiencing worsening heart failure.
