SYSTOLIC vs. DIASTOLIC - High & Low Blood Pressure Message Board

Lenin · 01-21-2005, 07:45 AM

A recent post of ZUZU's got me thinking about this subject so I thought I'd open a discussion on which is/should be more important.
Systolic is the highest instantaneous pressure that the heartbeat can generate in the largest arteries of the body; diastolic is the lowest that the pressure drops between the systole peaks. If you look at a graph of pressure you see that most of the graph is far closer to the diastolic than the systolic.
So in the past, the consensus was that contol of diastolic was the best standard for good blood pressure management (and judgement about WHETHER to mange at all.)
In recent years, emphasis has been put more and more on SYSTOLIC pressure. The logic is that a STROKE or blown artery, which is probably the most devastating event that BP can generate would occur only at a SYSTOLE, i.e., a hose will burst at it's HIGHEST pressure, not its lowest.
Little by little I think I am spotting a revival of interest in the diastolic as the more important. These swings can make us patients a bit dizzy, eh wot?

Another concept that has reared its head in the last decade is "PULSE PRESSURE" defined as the difference between systolic and diastolic. It is thought to be a measurement of arterial "stiffness" and may be related to the amount of plaque and calcification that had "hardened" the arterial walls. (Any oldies might remember the term "hardeniing of the arteries" which was loosely tossed around to mean everything from heart disease to senility.) Of course a high systolic has the most impact on amplifying this "stiffness."

Here's my take on the matter, which probably differs from some current norms. I think that diastolic control is very important because, it's the ENDLESS, unremitting pressure on the delicate tubules in the kidney that is a very dangerous aspect of blood pressure. It's also the one aspect of blood pressure that is self perpetuating, i.e., hypertension>>kidney damage>>hypertension.
The pulse pressure, while an interesting phenomenon indicating likely vascular damage, is only illustrative. Controlling pulse pressure (basically, systolic control) won't reverse the arterial damage or the actual "stiffness" just the ability to notice it readily...like painting your speedometer black won't make the car go slower, just your ability to determine the speed.

Of course, nobody could deny the huge stroke risk of a systolic over 200, but using a handful of drugs to get a 145 or 150 down to 135 might not be as wise as some practitioners think. There seems to be some evidence that lowering diastolic (inevitable with these drugs) below 80, or even 82 if I remember correctly, shows a detrimental effect on life expectancy (J-curve phenomenon).

How do you feel about the subject of systolic/diastolic? Any interesting study results you've seen? Anything anecdotal?

mgraylorn · 01-21-2005, 09:59 AM

I had a routine followup visit for my hypertension just this past Tuesday. I have "white coat", but my pressure was pretty good, 127/87. (The doctor had relocated to a new building, maybe my office pressure will be lower now, lol!) At home I average around 116/65, but sometimes a lot lower, and I told her that. She told me something that confused me, she said, "Just try to keep it below 130/85 for a resting rate most of the time." At home I am almost always much lower than that for a resting reading. This makes me wonder if I am over medicated.

I specifically asked what was current thinking, systolic or diastolic more important, and I asked about pulse pressure. She said pulse pressure was an old outdated concept and that neither systolic or diastolic were more important - if either one of them was too high then that was a problem.

I like my doctor and I think she is pretty sharp and current with the literature. I'm not putting her words out as gospel, but that is what I was told.

I guess I should add that she was probably talking about normal people like me without underlying medical conditions beyond hpertension.

Random2 · 01-21-2005, 12:04 PM

I don't think that any of the GP's know what is what. They keep changing their minds. They keep changing the guidelines & GP's have a reduced role in today's society. If everyone with high readings at the doc. took b/p meds. 50% of the population would be zombies. I am going to a specialist to see if they have some knowledge. I am tired of having more knowledge about B/P than my GP. Anything under 130/85 is alright??? I thought that 115/75 were the new guidelines? Numbers are just numbers.....unless you are like 190/110.

Lenin · 01-21-2005, 12:27 PM

Quote:

Originally Posted by mgraylorn

) At home I average around 116/65, but sometimes a lot lower, and I told her that. She told me something that confused me, she said, "Just try to keep it below 130/85 for a resting rate most of the time." At home I am almost always much lower than that for a resting reading. This makes me wonder if I am over medicated.

mgraylorn,

Two points:
A. CAN I HAVE YOUR DOCTOR...PLEASE PLEASE! How logical she is, saying that aiming for 130/85 is good control.
B. More seriously, if I were you, getting a consistent 116/65 at home, I would definitely cut my dosage starting with the meds that are most bothersome; if none are, then I'd cut the most expensive (usually the ARB or the Norvasc

)

Random2 · 01-21-2005, 12:47 PM

Lenin,

I agree. I want her GP as well.

If I average 112-116 over 62-68 with a pulse rate of 52-58 on 100 MGS of Atenolol & 5/20 of Lotrel would you advise me to do the same thing??? I'm only 34, 5' 11" 150 & have had bad side effects ever since being on the meds, especially the Atenolol. I am going to a specialist on my own freewill, because GP's don't seem to understand BP (at least the 3 that I have gone to). I can get readings like 156/86 at the GP, but never ever outside of the G/P. I have 300 readings over 2 years to prove it. I have white-coat & anxiety.