laplace law and ventricular hypertrophy

[Oh_Gee]

laplace law: Tension = pressure (afterload) x radius

can someone explain the relationship between this law and ventricular hypertrophy? what variable causes hypertrophy to happen?

is it because of

increased afterload (caused by high blood pressure)> which leads to an increased tension. heart will try to decrease tension by decreasing radius. decrease lumen radius by making the walls of the ventricle thicker

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[QueenJames]

There is increased tension due to something such as aortic stenosis (in the LV) or pulmonic stenosis (in the RV). TO compensate for this increase, then the THICKNESS will also INCREASE.

Tension = (2 X P X R) / Thickness
(an increase in the denominator factor of Thickness will lead to a decrease in the Tension).

I think.

 

[XxThaDoggxX]

^^ Correct. To compensate for the increase tension, the wall thickens (Because you have increased resistance from increased after load, you increase the thickness to get increased contractility and overcome the afterload)

Due to the law of Laplace Tension is INVERSELY proportional to thickness T = P x r / 2H H being width or thickness

 

[zmiller5000]

laplace law: Tension = pressure (afterload) x radius

can someone explain the relationship between this law and ventricular hypertrophy? what variable causes hypertrophy to happen?

is it because of

increased afterload (caused by high blood pressure)> which leads to an increased tension. heart will try to decrease tension by decreasing radius. decrease lumen radius by making the walls of the ventricle thicker

Couple of notes: Blood pressure is not afterload..this is a common misconception. Increased afterload IS increased tension, it does not lead to increased tension. The tension on the heart is the wall stress that is trying to keep the ventricle from contracting. If I have identical pressures hooked up to ventricles with different geometries..say a normal ventricle and a dilated ventricle, then the afterload on the dilated ventricle is greater. Similarly, for your question, if I have identical pressures hooked up to a thick ventricle and a thinner ventricle, the thicker ventricle has a lower afterload. Afterload describes both the effect of pressure and the GEOMETRY of the ventricle affected by that pressure. Different shaped ventricles will distribute pressure differently. Hypertrophy occurs due to chronically high afterload typically from hypertension, aortic stenosis, coarcts, etc.