The Intercept and Slope of breathlessness/chest pain-heart rate relationship in patients with Coronary artery disease using Exercise tolerance test

The most common cause of morbidity and mortality all over the world is Coronary artery disease. The traditional risk factors for Coronary artery disease are hypertension, diabetes mellitus, family history, smoking, dyslipidaemia and obesity. Chest pain and dyspnoea are the two common complaints of patients with Coronary artery disease. The CAD patients are the largest to be recruited in exercise testing. Bruce protocol is most commonly used in exercise testing. Patients developing chest pain and ECG changes are considered ETT positive. Heart rate determines myocardial oxygen demand. The heart rate increases during exercise due to sympathetic activation and parasympathetic withdrawal.Dyspnoea and pain result from interactions between multiple physiological, psychological, social and environmental factors. Both these sensations strongly motivate adaptive behaviour to regain homeostasis, and patients often experience both conditions. Anterior insula has a strong role that activates in pain and dyspnoea. Pain and dyspnoea which are the major complaints of CAD, can be measured using verbal descriptor or VAS. There is a need of simultaneous recording of chest pain and dyspnoea in patients with CAD. This review includes the studies done previously to record dyspnoea, through VAS and to measure intercept and slope in healthy volunteers and in patients with CAD