The understanding of how the heart works is fundamental for our intensivist to provide cardiovascular support.ย
Inotropes are pharmalogical agents that increase force of ventricular contraction, usually ร-effect
Vasopressor constricts blood vessels, ฮฑ-effect.
Chronotrope increases heart rate, ร-effect.
Adrenaline
- both ฮฑ and ร-effect.
- inotope, vasopressor and chronotrope
- ร2 effect at low doses causing vasodilatation in skeletal muscle thus lowering SVR.
- ฮฑ-vasoconstrictor effect at higher doses will increase SVR and myocardial oxygen demands, with adverse effect on cardiac output.
Noradrenaline
- ฮฑ-effect, vasopressor
- indicate din septic shock when hypotension is due because of massive peripheral vasodilatation which will persist despite fluid/volume resuscitation.
Dobutamine
- ร1 and ร2 effect.ย
- Inotrope, vasodilator
- ร1 effect increases heart rate and force of contraction
- ร2 causes mild vasodilatation
- This is the first choice of inotropes in cardiogenic shock due to left ventricular dysfunction.
- Dobutamine and low dose dopamine in conjunction used in cardiogenic shock to increase blood pressure by increasing cardiac contractility and urinary output (UO). This will increase renal perfusion.
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