How Digoxin (lanoxin) works:
INCREASES CONTRACTILITY OF THE HEART: TECH Term, it creates a POSITIVE INOTROPIC EFFECT. The Positive INOTROPIC Effect occur secondary to the inhibition of of the sodium potassium adenosine triphosphate pump.
When the actions of the Sodium Potassium Adenosine Triphosphate Pump is inhibited, the overall result is : a Stronger Myocardial Contractility (stronger heart beat).
Digoxin: Augments Cholinergic stimulation via the vagus nerve of the parasympathetic nervous system commonly called Vagal Tone.
Vagal tone: sensitize cardiac baroreceptors, reducing sympathetic stimulation as a result cardiac efficiency and output improves even more.
Digoxin: Decreases the velocity of electrical conduction and prolongs the refractory period in the conduction system: site between the Atria and the ventricles (SA node to the AV node).
Result: The heart cell remain in depolarization mode longer, reducing heart rate but improving efficiency.
ChronoTropic, InoTropic and Dromotropic And DiG.:
Positive InoTropic EffecT: Increased force and velocity of the heart contractions without a corresponding increased oxygen consumption.
Negative ChronTropic EffecT: Decreased heart Rate.
Negative DromoTropic EffecT: Decreased automaticity of the SA node, Decreased AV Nodal conduction, reduced conductivity and the bundle of His, and prolongation of the Atrial and Ventricular Refractory period.
Digoxin Does More:
- Increases Stroke Volume
- Reduces Heart size during diastole
- Increases heart circulation
- Promotes tissue perfusion and diuresis as a result of improved blood circulation