Hypertension, heart failure and coronary heart disease Flashcards
What is hypertension?
A blood pressure being higher than normal-changes often but optimal tends to be <120 <80
How large is the blood pressure problem?
It is the leading cause of death in the world
What is ambulatory blood pressure?
Its the blood pressure that can be measured by a cuff-often 5-10mmHG lower than clinically determined
Current practice aims around 120mmHg
How does blood pressure change with age?
Systolic BP rises with age by Diastolic does not-and lowers very slowly
but BP going higher is normal-and sign of health because heart is healthy
What is pulse pressure?
Pulse pressure is difference between SBP and DBP
What are the relations between blood pressure and mortality?
There is no threshold-even at SBP 110 is a risk factor to death-but as you rise in BP, exponential increase of death
Even with perfect health-cant get rid of problem, only reduce it-people will still be suceptible
What is primary hypertension?
Primary-identifiable causes, such as renal diseases, tumours, contraceptives, rare genetic causes -about 5-15% of hypertensions (pretty rare more or less)
Single gene causes are even rarer (monogenic)-often sodium channels
Complex polygenic-more common
What is the secondary hypertension?
Idiopathic-no cause
What are the links between blood pressure and genes?
Twin studies show that 30-50% of BP changes can be due to SNP’s-but we havnt identified that many
monogenic are rare-most are small genes with small effects, and interact with sex, and etc
What are the signs of established hypertension?
It describes high BP for a long time-often with higher TPR, lower arterial compliance, but normal CO, blood volume-but can have shifts in volume location (lower venous compliance)
What causes TPR modification in hypertension?
MAYBE-vasocontricion on the short term
Maybe structural narrowing, remodelling and loss of capillaries?
What is isolated systolic hypertension
SBP >140 and BP<90 -not to do with TPR, but only arterial compliance lower-reflexion of the wave on the solidified arteries
What are the 2 main causes of hypertension?
The kidney is thought to have a major role in creating and maintaining hypertension. PSNS and SNS also seem to have a role in early hypertension
Kidney is a major regulator of sodium/water/ecf regulator-if you transfer a diseases kindey to another mice, its BP rises=recall it also damages it
What damages can hypertension cause?
Increase risk of CHD, Stroke, arthermatous didease, heart failure, atrial fibri, dementio, retinopathy
How does hypertension affect the heart?
A high arterial BP means the heart has to beat against a larger afterload-more likely to fail. But also larger thicker left wall to push out = second main cause of heart failure (on the rise) 2-3x increase
How does hypertension affect large arteries and vessels?
It causes a thickening of the media of the arteries-proliferation of SMC and activation of endothelia
Can also cause aneurysm-as tension rises, the wall weakens-expands and as it expands, the pressure on it increases => blood vessel burst (actual rare-strokes are embolism not aneurysm)
How does hypertension affect the eye and microvasculation?
eye-Thcikening of the small atries wall, vasospasm, impaired perfusion and leakage into tissue -pretty rare
For microcirulation-tickening of th wall and lowering of microvascular-less perfusion and increases resistance
What are main treatments of hypertension
Diet and lifestyle modification
ACE inhbitors-stop from angiotensin to become angotension II => less ADH, aldosterone and tubular sodium reabosrption-less water retention
also causes less constiction and SNS exitation
Angiotensin inhbitors do the same
Diuretics- only rare for people in hypertensive crisis-Thiazides-do not work because of diuretics but does that-we dont know how it reduces TPR, but it works
beta blockers-rare for hypertension-block heart B1 receptors to reduce Cardiac output, and Kindey B1-reduce renin
Calcium channel blocks-matter in SMC and cardiomycoties=>reducing the amount of Ca in cells reduces the contraction of these cells=> reduces contractility (and some reduce rate of condution, beating weaker and slower
How would you describe cardiac output?
Volume of blood that leaves either side of the hear-usually in the context of the left ventricule
Influenced-by preload, afterlaod and cardiac contractility
measured as strove volume x Heart rate
inadequate in heart failure
How would you describe ejection fraction? How do you measure it?
Stroke volume is End diastolic volume-End systolic volume-and the ejection fraction is SV/End diastolic volume
above 55% is normal
under to 45 is reduced, 30-44 is moderatly reduced, and <30 is severly reduced
measured in echocardiograms
Define heart failure
inability of the heart to keep up with demand-inadequate perfusion of ograns-lead to congestrion in lungs and legs-lots of symptoms and signs
looking at echocardiograms-usually heart has tachycardia-not beating as well-spastic
Walls are thinner
What are the 3 types of heart failure comparaison?
Left vs right, chronic vs acute, normal ejection fraction vs abnormal
Describe left vs right heart failure
Left heart failure-dysfunction with filling or ejection=>the blood backs up and leads to congestion-this then leads to pulmonary hypertension and blockage-breathless, coughing, wheezing, diziness, cyanosis
Right heart failure-also filling or ejection (right ventricule)-can be caused by increase in afterload of pulmonary circulation (caused by left heart failure)-ahrder to eject against it =>often secondary to left hear failure
Describe Acute vs chronic heart failure
Chronic-more common-slow onset-due to infection, pulmonary embolism, MI or surgery
acute-similar symptoms, but rapid onset
