Beta - Blockers
Atenolol - cardioselective
Carvedilol - only one used in CCF (CHF)
- - blockers inhibit the binding of catecholamines (e.g adrenaline, noradrenaline, dopamine) at the Beta 1
- adrenoreceptor site in the heart
- o Pharmacologically, blockade of Beta 1 receptors decreases rate, conduction velocity, myocardial contractility and cardiac output
- o Anti-hypertensive effect results from decreased cardiac output without a reflex increase in peripheral vascular resistance;
- - diminished sympathetic outflow from the vasomotor centre in the brain to the peripheral blood vessels; reduced renin release by the kidney
- o They also have direct effect on the heart itself (blocking the ␣1adrenoceptor-mediated increase in rate (chronotropicity) and force (inotropicity) of cardiac contractions).
- o ␣1-blockade can also decrease conduction velocity within the heart, therefore some ␣-blockers such as sotalol can be prescribed for certain tachyarrhythmias.