PHTY200 Lecture Notes - Lecture 10: Renal Artery Stenosis, Heart Failure, Coronary Artery Disease
Document Summary
Reducing the sensitivity of smooth muscle cells in the walls of arteries to the normal stimuli to contract. Widening of the arteries improving the blood supply to the heart muscle in angina pectoris. Lowering ventricular wall stress and myocardial oxygen demand. Enhanced entry of calcium into cell enhanced contraction. Effective only against v tach or v fib. Do not affect repolarisation in most tissues, however do prolong the refractory period in. Av nodal conduction: mild hypotension, systematic gi, rash, fever, Class ib: cns confusion, dizziness, seizures, nausea, diarrhoea, do not lengthen the qt interval, therefore unlikely to cause arrhythmia. Class ic: pro arrhythmic dangerous drugs to use, mild negative inotropy can precipitate chf, cns confusion, dizziness, blurred vision. Decrease cardiac force of contraction, heart rate, and conduction velocity. The effects of beta blockade are also mild when someone is at rest. When the sympathetic nervous system is a(cid:272)ti(cid:448)ated, the effe(cid:272)ts of (cid:271)eta (cid:271)lo(cid:272)kade are much more obvious.
