Given below are the abnormal conditions related to blood circulation. Name the disorders.
$(a)$ Acute chest pain due to failure of $O_{2}$ supply to heart muscles
$(b)$ Increased systolic pressure

(A) This condition is known as 'Angina Pectoris'. It occurs when there is an inadequate supply of oxygen to the heart muscles,leading to acute chest pain.
$(b)$ This condition is known as 'Hypertension' (High Blood Pressure),which refers to a persistent increase in systolic or diastolic blood pressure.