Hypertension: Pathology, Clinical Features and Complications

00:00 What does it look like on pathology? Hey, this is pathology. Right? So there are 3 hypertension related forms of small blood vessels disease. The one that is shown here is hyaline arterial sclerosis. All of these changes by the way are going to be in the kidneys.

00:15 So, in here you can see the kind of irregular blabs on the left and the right lower corner.

00:21 Those are glomeruli. And the thing marked with the 1 is renal arteriole which is showing some intimal hyperplasia, but the renin lesion I want you to see is the one marked 2. There is a thickened arteriolar wall with deposition of hyaline. This is a response of the renal vasculature that try to limit the effects of high blood pressure within the kidney parenchyma. It's not entirely effective but it's something that we can recognize if we look at the kidneys of a hypertensive patient. The other thing that can happen is you get intimal hyperplasia and this is an elastic tissue stain of again kidney and you're seeing that inside of the ring of the internal elastic lamina there is a thickening of the intima.

01:05 That's hyperplastic arteriolar sclerosis. Another change where the kidney is trying to minimize the higher blood pressure and its effect on the renal parenchyma. And the final one that only occurs really in kind of malignant hypertension is a necrotizing arteriolitis.

01:23 Basically we now get fibrin and thrombosis of small vessels and this is a very poor prognostic sign. So this is a 3-classic kind of changes associated with renal vascular hypertension. So, signs and symptoms. Unfortunately, vast majority of high blood pressure is completely asymptomatic. You only know it by measuring it. So if you never get measured, you never see a doctor, it's very likely that you will be walking around with high blood pressure and don't know it. It will become asymptomatic for a while but then it becomes symptomatic when you have complications of end organ disease. So you can get the kidney disease that we talked about with loss of renal vascular flow. You can get strokes, you can get changes within the eye grounds that will show you and you can also, as the heart responds to the higher blood pressure, it undergoes hypertrophy.

02:17 So, an acute increase in blood pressure, that hypertensive crisis will have immediate ramifications including things like severe headache and then even stroke. So, nonspecific symptoms of hypertension include headaches especially early morning headaches can include dizziness, blurred vision, tinnitus so ringing in the ears, and a flushed appearance.

02:43 Obviously all of these are non-specific and just because you have a flashed face doesn't mean you have hypertension. But you need to at least consider getting your blood pressure measured. An important systemic cardiovascular complication of hypertension is atherosclerosis and hypertension is one of the 5 major risks associated with the development of severe atherosclerosis. It's also going to be a cause of hypertensive heart disease where we have increased myocyte hypertrophy and there is not a compensatory increase in the vasculature so you end up with very big cardiac myocytes able to squeeze at a higher pressure but not necessarily perfectly well vascularized and then you can have a failure of that heart causing the ischemic cardiomyopathy in the setting of longstanding hypertension. You can get aortic aneurysm. So you can get dilation of aorta as a result of damage caused in a hypertensive setting. You can get aortic dissection so rupture of the vessel wall and we'll talk more in a subsequent talk about aneurysms and dissections. And finally, the most ___ complication is certainly immediately a stroke or you can have transient ischemic attacks or TIAs, but what is happening is that you are getting now bleeding as a result of the rupture of small blood vessels and that can eventually lead to a large hemorrhagic stroke. You can get a subcortical leukoencephalopathy or multi-infarct dementia. This will lead to memory loss and other cognitive changes. And finally there is hypertensive nephrosclerosis which we've already seen. You get scarring. So when the kidney tries to maintain blood flow into the glomerulus and it has all those arteriolar changes, it's also trying to minimize potential damage to the the glomerulus. As a result, it may close off the blood supply entirely and as a result of that you get glomerular sclerosis basically scarring of the glomeruli. This will lead to lack of filtration obviously. All those areas shown are dead and no longer filter and over a period of time you can develop chronic kidney disease. In the eye grounds, the ophthalmologic complications are those associated with hypertensive retinopathy, high blood pressure in delicate vascular beds. So one of the ways that we can see it even without having severe disease is arteriovenous nicking. So whether the arteries and veins cross, you can have a prominent venous dilation under increased pressure and that gives you an apparent nicking or apparent kind of block of the flow through the vein. It's only apparent there isn't a block but we can recognize it as arteriovenous nicking on a retinal exam. In severe disease, you can get papilloedema so you get increased vascular permeability especially around the fovea and then you can also have cotton wool spots and hemorrhage representing actual vascular rupture. And with that, we've covered from beginning to end how hypertension occurs, how normal blood pressure is regulated, and what are the complications.