what type of disease is coronary heart disease
Coronary artery disease Coronary artery disease (CAD), also known as ischemic heart disease (IHD),[13] refers to a group of diseases which includes stable angina, unstable angina, myocardial infarction, and sudden cardiac death.[14] It is within the group of cardiovascular diseases of which it is the most common type.[15] A common symptom is chest pain or discomfort which may travel into the shoulder, arm, back, neck, or jaw.[4] Occasionally it may feel like heartburn. Usually symptoms occur with exercise or emotional stress, last less than a few minutes, and improve with rest.[4] Shortness of breath may also occur and sometimes no symptoms are present.[4] In many cases, the first sign is a heart attack.[5] Other complications include heart failure or an abnormal heartbeat.[5]
T wave Inverted T wave is considered abnormal if inversion is deeper than 1.0 mm. Inverted T waves found in other leads other than the V1 to V4 leads is associated with increased cardiac deaths. Inverted T waves associated with cardiac signs and symptoms (chest pain and cardiac murmur) are highly suggestive of myocardial ischaemia.[4] Other ECG changes associated with myocardial ischaemia are: ST segment depression with an upright T wave; ST segment depression with biphasic T wave or inverted T wave with negative QRS complex;[5] T wave symmetrically inverted with a pointed apex, while the ST segment is either bowed upwards or horizontally depressed, or not deviated; and ST segment depression progressing to abnormal T wave during ischaemia free intervals.[4] However, ST segment depression is not suggestive of ischaemic location of the heart. ST segment depression in eight or more leads, associated with ST segment elevation in aVR and V1 are associated with left main coronary artery disease or three-vessel disease (blockage of all three major branches of coronary arteries). ST segment depression most prominent from V1 to V3 is suggestive of posterior infarction. Furthermore, tall or wide QRS complex with an upright T wave is further suggestive of the posterior infarction.[5]