CVS pharmacology Flashcards
Dobutamine, adrenaline and noradrenaline are all agonists (beta-adrenoreceptor ligands upon the heart). What are the pharmodynamic effects they have?
- Increase in force, rate and cardiac output and O2 consumption
- Decrease in cardiac efficiency (O2 consumption is more than cardiac work)
- Can cause disturbance in cardiac rhythm (arrhythmias)
What are the clinical uses for adrenaline?
Cardiac arrest (sudden loss of pumping function) Emergency treatment of asthma Anaphylatic shock (life threatening respiratory distress and often vascular collapse)
What are the clinical uses for dobutamine?
(selective for beta1-adrenoreceptors)
Acute, but potentially reversible, heart failure (e.g following cardiac surgery, or cardiogenic shock)
Where is B1 and B2 found and what do they both activate?
B1- found in the heart
B2- Smooth muscle of arterioles and bronchioles
Activate cAMP
What is dysrhythmias?
Treatment of disturbances of cardiac rhythm
What can excessive sympathetic activity associated with stress or disease lead to?
Tachycardia or spontaneous activation of ‘latent cardiac pacemakers’ outside nodal tissue
What is the role of beta blockers?
Decrease excessive sympathetic drive and help restore normal sinus rhythm
What is the Effect of Non-Selective Muscarinic ACh Receptor Anatgonists Upon The Heart? - Atropine
Modest increase in heart rate
No effect upon arterial BP
No effect upon the response to exercise
What are the clincical uses of atropine?
- To reverse bradycardia following myocardial infarction (vagal tone is elevated)
- As an adjunct to anaesthesia
- In anti cholinesterase poisoning (to reduce excessive parasympathetic activity)
What was Atropa belladonna used for as a cosmetic product in the early 20th century?
Enlarge the pupils of their eyes
Its a bizarre delirium and causes hallucinations
What is Digoxin?
A cardiac glycoside that increases contractility of the heart
