Elevated Diastolic Pressure? (isolated)

[unsung]

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So what would cause an isolated elevated diastolic BP?

Let's say systolic is ~ normal or may be slightly elevated. But definitely not as dramatically as the rise in diastolic. Meaning there's a very narrow pulse pressure.

I'm just curious... and never really understood this.

 

[GwinnettPreMed]

I think aortic stenosis or something else that impedes outflow from the ventricle could do this - body tries to compensate for decreased CO by increased sympathetic output/vasoconstriction. Because of the outflow problem the heart can't raise the systolic pressure proportionally. I haven't seen this in a patient before so I may be wrong but it makes sense to me.

 

[nkhan]

I think aortic stenosis or something else that impedes outflow from the ventricle could do this - body tries to compensate for decreased CO by increased sympathetic output/vasoconstriction. Because of the outflow problem the heart can't raise the systolic pressure proportionally. I haven't seen this in a patient before so I may be wrong but it makes sense to me.

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In aortic stenosis you have both systolic (can't get the right ejection fraction out) and diastolic (elevated LVEDP). With elevated LVEDP you have elevated diastolic pressure and a decreased pulse pressure (PP=systolic-diastolic), one of the hallmarks of AS. I've seen this q in the qbanks also.

 

[sgod34]

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In aortic stenosis you have both systolic (can't get the right ejection fraction out) and diastolic (elevated LVEDP). With elevated LVEDP you have elevated diastolic pressure and a decreased pulse pressure (PP=systolic-diastolic), one of the hallmarks of AS. I've seen this q in the qbanks also.

Isn't systolic pressure based more on volume, where diastolic is based more so on TPR?

I believe some causes of isolated diastolic hypertension are hypothyroidism, Cushing's, Conn's, and Pheochromocytoma/Neuroblastoma. Pretty much anything that acts on alpha-1 receptors will increase TPR, and have a much greater effect on diastolic pressures rather than systolic. I think the big key is to remember in hypothyroidism although you get decreased HR, you still see HTN clinically. In fact, whenever you get a patient with isolated diastolic htn, one of the first things you want to think about is checking TSH levels.

 

[bdc142]

Well Goljan says that the increase of diastolic BP with hypothyroidism is due to the "retention of sodium and water". Can anyone explain why that's true?

 

[thehundredthone]

I'm not sure, I remember reading that hypothyroidism causes endothelial dysfunction and impaires relaxation of vascular smooth muscle thereby increasing vascular resistance. This is the cause of diastolic hypertension in hypothyroidism.

In hypothyroidism, endothelial dysfunction and impaired VSM relaxation lead to increased SVR. These effects lead to diastolic hypertension in ≈30% of patients, and thyroid hormone replacement therapy restores endothelial-derived vasorelaxation and blood pressure to normal in most

EDIT: I found what Goljan's source might have been. I don't think it holds as much ground any more.

The mechanism of hypertension in patients with hypothyroidism is not known. Our finding of low stimulated PRA levels in 52% of these patients confirms previous reports of low PRA levels in patients with hypothyroid hypertension. Thyroidectomy reduced PRA in rats. These results might indicate that fluid retention and extracellular fluid volume expansion in hypothyroidism might be the mechanism of the hypertension.

 

[Anigma07]

Well Goljan says that the increase of diastolic BP with hypothyroidism is due to the "retention of sodium and water". Can anyone explain why that's true?

Low thyroid levels would decrease the GFR and hence increase water and Na absorption. As touched on earlier, this would increase the diastolic BP.

 

[arda]

hypothyroidism causes diastolic hypertension.It is really interesting that both hyperthyroidism and hypothyrodisim causes hypertension.

Explanation is here
http://www.medscape.com/viewarticle/733788_3

 

[oaAnne71]

ok, lets say there's a guy in his 60's with a bp of 147/107, pulse pressure 40 and heart rate of 92bpm.
healthy diet, low sodium, low fat, low cholesterol, no diabetes or hypothyroidism, light to moderate exercise, non-smoker, light to moderate drinker.
What's going on with the diastolic pressure? And i'm guessing this is isolated diastolic hypertension, which I believe is more common in younger people!
How do I help get this blood pressure to within acceptable limits without medication?
Thanks All.
Offshore Medic

 

[Jabbed]

Pericardial tamponade produces elevated diastolic pressure and narrowed pulse pressure. Not sure if that's too sexy a process for your original question though..