Angina

• ischaemic heart muscle —> release of lactic acid, histamines, kinins

—> stimulate pain endings in heart

—> pain impulses conducted to CNS (angina pectoris)

• Pain felt beneath upper sternum, neck, & left arm [during embryological development heart & associated nerves develop in neck and share same spinal cord segments]

Stable Angina [2° Mv02 (increased myocardial 02 demands)]

(Chronic angina)

· no change in angina symptoms within last 6 months

· usually associated with a smooth vessel wall atheroma (fixed lumen diameter) or spasm

· associated with early coronary atherosclerosis

· syndrome of at least several weeks in duration

· provoked by predictable activities that increase myocardial O2 demands eg increased activity

· episodes of angina are not increasing in severity or number

· angina is routinely relieved by ceasing precipitating activity or nitroglycerin

· the progression of coronary stenosis is accompanied by collateral blood supply

Unstable Angina [2° ¯MD02 (decreased myocardial 02 delivery)]

(Crescendo angina pectoris, preinfarction angina)

· associated with late coronary atherosclerosis

· a relative medical emergency requiring hospitalisation

· includes patients with new-onset effort angina, changes in pattern of previously stable angina (worsening), angina at rest

· pain is often more intense and prolonged (> 30 min) than stable angina

· the progression of coronary stenosis is occurring more rapidly than the development of collateral blood supply

Prinzmetal’s Angina Pectoris

(Variant angina)

· may or may not be associated with coronary atherosclerosis

· pain occurs at rest

· associated with elevated ST segments

· not related to effort or emotional stress

· coronary spasm is postulated