heart problems Flashcards
what are modifiable factors that will limit hypertension?
- smoking
- type 2 diabetes
- obesity
- diet
- physical activity
- alcohol
(Brooker et al, 2013)
what are non modifiable factors that cannot be changed and may cause hypertension?
- age
- sex
- ethnicity
- genetics
(Brooker et al, 2013)
what is hypertension?
- raised arterial blood pressure and determined by cardiac output and the total peripheral resistance of the circulatory system
(Brooker et al, 2013)
what can hypertension cause?
- stroke
- myocardial infarction
- kidney dysfunction
(Brooker et al, 2013)
what is the average BP for someone with hypertension?
should be below 130/80
(Brooker et al, 2013)
why should people have a lower BP?
- lower pressure associated with lower risk
- cardiovascular risk increases linearly from 115/70 to 170/100
- lowering BP can lead to relative reduction in risk of around 22% for ischemic heart disease and around 41% for stroke
(Brooker et al, 2013)
what BPs would people have if they were stage 1, 2 and 3 hypertensive?
1 = systolic - 140-159
diastolic - 90-99
2 = systolic - 160- 179
diastolic - 100-109
3= systolic - >180
diastolic - >110
(Hussain and Prerana, 2018)
what is mean arterial pressure (MAP)?
- cardiac output X peripheral resistance
- altering either of these will have an effect on the blood pressure
(Brooker et al, 2013)
how is the cardiac output measured?
- heart rate X stroke volume
- expressed as the volume of blood pumped by the heart in one minute
(Brooker et al, 2013)
how do you work out the end systolic and end diastolic volume?
end diastolic = how much the heart fills
end systolic = how much the heart empties
(Brooker et al, 2013)
how does filling of blood into heart happen?
- determined by return of blood from venous system, and emptying the heart by the contractility of the heart muscle
- increase in blood volume can result in an increased cardiac output
(Brooker et al, 2013)
what total peripheral resistance (TPR)?
sum of resistance offered by the small arteries and arterials to the flow of blood
(Brooker et al, 2013)
what is Poiseuille’s law?
- resistance to flow in any blood vessel will be related to viscosity of blood
(Brooker et al, 2013)
why is the radius of the vessel important?
- The length of vessels and blood viscosity tend to not change so the most important factor is the radius of the vessel itself
- Small changes in radius will lead to large changes in peripheral resistance and potentially blood pressure
(Brooker et al, 2013)
how is blood pressure regulation achieved?
- through autonomic nervous system and hormonal mechanisms
- immediate control is control managed by Baroreceptors reflexes
(Brooker et al, 2013)
how is increased BP detected?
- sensory endings in carotid sinuses and aortic arch
- results in a decrease in sympathetic stimulation of the heart reducing heart rate, reducing BP
(Brooker et al, 2013)
what are complications of hypertension on the heart?
- left ventricular hypertrophy can lead to diastolic heart failure
- cardiac arrhythmias
- myocardial infarction
- sudden death
(Brooker et al, 2013)
what are complications of hypertension on the brain?
- ischaemic or hemorrhagic stroke
- associated with impaired cognition in elderly
(Brooker et al, 2013)
what are complications of hypertension on the kidneys?
- major factor in development of renal disease and accelerating progression of other underlying renal disease
(Brooker et al, 2013)
what are complications of hypertension on peripheral arteries?
- blood vessels are common site of hypertension related complications
- atherosclerosis is underlying issue in development of peripheral vascular disease leading to a narrowing of the vessel, and pain where there is insufficient perfusion of tissues
(Brooker et al, 2013)
what are lifestyle changes that can help combat hypertension?
- more exercise
- balanced diet
- no smoking
- no alcohol
- reduce sodium intake
- maintain calcium, magnesium, sodium intake
(Brooker et al, 2013)
what medications can be taken for hypertension?
- diuretics (furosemide)
- calcium channel blockers (amlodipine)
- ACE inhibitors (ramipril)
- Beta blockers (propanolol, atenolol)
(Brooker et al, 2013)
what is ischemic heart disease?
- lack of blood and demand for the heart muscle
- coronary arteries are unable to supply sufficient oxygen to the heart muscle for it to function
(Brooker et al, 2013)
what can ischemia look like?
- can be minor and reversible: angina pectoris causing pain and discomfort upon exertion
- can be major irreversible event resulting in cell death of the heart muscle and possible death of individual, this is myocardial infarction
(Brooker et al, 2013)
what are coronary arteries?
- branches off the aorta that are immediately behind the cusps of the aortic valve
- get good supply of oxygenated blood
(Brooker et al, 2013)
what do the left and right coronary arteries do?
right = runs down and over right ventricle and its branches supply the right ventricle and right atrium
left = runs down over the left ventricle, branching as it goes and has major branch called left circumflex branch which runs posteriorly around heart
(Brooker et al, 2013)
why is the left coronary artery very important?
- left coronary artery and branches supply larger part of heart (left ventricle)
- area of heart muscle usually only supplied by one branch of artery
(Brooker et al, 2013)
what would happen if an artery is blocked?
- area of muscle it supplies will be starved of oxygen and without some form of rapid intervention will die
(Brooker et al, 2013)
what is the normal response of the artery to cardiac ischaemia?
- it would vasodilate by reducing its vascular tone
- usually sufficient enough to restore adequate blood supply if stenosis (narrowing of vessel) is not too severe
(Brooker et al, 2013)
what will happen if a heart vessel is reduced to less than 70% of its normal diameter?
- coronary blood flow will be barely sufficient to supply the oxygen demand of the heart muscle at rest
- if stenosis reduces vessel to less than 90% diameter, ischaemia will develop even at rest
(Brooker et al, 2013)
what are the main causes of ischaemia?
- unstable angina
- atherosclerotic plaque becoming exposed plus thrombus formation will lead to worsened ischaemia
- vascular tone or spasm
(Brooker et al, 2013)