• Angina pectoris is chest pain caused by reduced oxygen supply (hypoxia) to the heart muscle, usually due to coronary artery disease.

• Chordae tendineae help anchor the atrioventricular (AV) valves. If severely damaged, they can lead to valvular incompetence, which may cause backflow and reduced forward flow, ultimately reducing outflow of blood to the aorta.

• Heart block refers to impairment in the conduction of electrical impulses in the heart, particularly between the atria and ventricles (usually at the AV node). It is not defined by sudden muscle damage due to poor blood supply - that description fits myocardial infarction (heart attack).

• If the SA node (primary pacemaker) is dysfunctional, the AV node can take over as a secondary pacemaker to generate impulses, though at a slower rate.