After reading this chapter, you should be able to:

state the key cardiovascular responses to hypoxia (18.1);

list the principal causes of acute circulatory failure (clinical shock) (18.2);

describe the reflexes that support blood pressure (BP) during hypovolaemia (18.2);

explain the cardiovascular basis of fainting (18.3);

define ‘clinical hypertension’ and list its main ill effects (18.4);

draw the hypertensive pressure pulse and explain (1) the rise in mean pressure; and (2) the disproportionate increase in systolic pressure (18.4);

outline the chief aetiological theories for hypertension (18.4);

define chronic heart failure and sketch the altered ventricular function curve (18.5);

outline the changes in excitation-contraction coupling and electrophysiology of failing myocytes (18.5);

list the changes in cardiac performance and peripheral circulation associated with heart failure (18.5);

explain dyspnoea and how oedema arises in heart failure (18.5).