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)
what would happen if someone has myocardial ischaemia?
outcome can depend on:
- severity (degree of blood flow reduction)
- the duration of ischaemia
- location of ischaemia
- compensation from other blood vessels
all can lead to reversible or irreversible myocardial damage
(Brooker et al, 2013)
what does stable angina look like in a patient?
- ischaemia usually mild and usually brought on by physical or emotional stress
- patients usually feel discomfort in chest that will be relieve in a minutes following rest
(Brooker et al, 2013)
what does unstable angina look like in patients?
- involve rupture of atherosclerotic plaque aggregation and thrombus formation
- discomfort persists for longer than 10 minutes and is more severe
(Brooker et al, 2013)
what is myocardial infarction?
- involves severe ischaemia which leads to ATP depletion and loss of contraction within minutes but does not mean full cell death and damage is reversible
- complete absence of blood flow for 20 - 30 minutes leads to irreversible injury, with necrosis complete within 6hours
(Brooker et al, 2013)
where do most myocardial infarctions occur?
- within the distribution of one coronary artery
(Brooker et al, 2013)
what are treatment options for MI and severe angina?
Reduce O2 demand and restore O2 supply!!!!!!
- reduce the work of the heart so it reduces its demand for oxygen
can do this by: - reducing stress both physical and emotional, bed rest and using drugs as appropriate to reduce pain and anxiety and so reduce the sympathetic drive
to the heart - Supply oxygen via a mask or nasal cannula to improve the
oxygen supply. - Use drugs to vasodilate coronary arteries.
(Brooker et al, 2013)
what would you do once a clear diagnosis of a patient who has MI has been made?
- restore blood supply as much as possible to area of damage
pharmacological: antithrombotic meds, fibrinolytic therapy (within 2 hours of onset symptoms) to breakdown thrombus
- cardiac catheter to introduce assent or even directly remove a clot
- surgical intervention can be possible, would be coronary artery bypass graft
(Brooker et al, 2013)
how is a normal heartbeat generated?
- from sinoatrial node or sinus node (natural pacemaker of heart)
- normal heart rate usually between 60-100 beats
(Brooker et al, 2013)
what is sinus bradycardia and what causes it?
slow!!!!!!!!!!
- the heart rate generated from the impulses from the sinus node is less than 60 beats per minute
- can be normal for some people
- if asymptomatic it doesn’t require treatment
- can also be caused by degeneration or damage to cells of sinus node or disease of atrioventricular node conduction
(Brooker et al, 2013)
how can bradycardia be seen physiologically?
- response to passes of respiratory cycle as you breathe in can be slowing of heart are so increased interval between R waves on ECG
- as you breathe out speeding up of heart rate with reduced
R-R interval will happen
(Brooker et al, 2013)
what happens when there is a first degree AV block in the AV conduction system?
- prolonged interval between P waves and R wave but there is 1 to 1 relationship between P and R waves so P waves is always followed by R wave even if it is somewhat delayed
(Brooker et al, 2013)
what happens when there is a second degree AV block in the AV conduction system?
- where P and R relationship begins to be lost
- either gradually extending interval between the P and R waves until an R wave is missed
- or where there is a constant interval between P and R waves but from time to time the conduction at the AV node fails and an R wave is missed
(Brooker et al, 2013)
what happens when there is a third degree AV block in the AV conduction system?
- complete lack of conduction across AV node, so P wave all follow its rhythm and the QRS complex will follow its own slower rhythm leading to a complete lack of relationship between the two
- leads to lack of blood supply to the brain
(Brooker et al, 2013)
how may a patient with third degree AV block present?
- light headedness
- fatigue
- shortness of breath
- fainting
(Brooker et al, 2013)
what are tachyarrhythmias?
- increased rates of contraction of the atria or ventricles or lack of coordinated activity contraction
(Brooker et al, 2013)
what is atrial tachycardia?
- due to one or more areas of atria firing off resulting in a continue to sell exciting activity in atria
(Brooker et al, 2013)
what is an atrial flutter?
- continuous cycle of impulse is generated in the atria and so P waves are generated at the maximum rate possible for the atria around 300BPM
- not uncommon, can be pharmacologically controlled
(Brooker et al, 2013)
what is atrial fibrillation?
- chaotic and uncoordinated excitation of cells all over the atria
- patients can be asymptomatic if ventricles continue to beat in a coordinated albeit slowed manner paced by AV node
(Brooker et al, 2013)
what is ventricular tachycardia?
- three or more premature ventricular beats on ECG
- usually occur where there is some structural damage to the heart and can be life threatening but can also occur in normal heart rate
(Brooker et al, 2013)
what are symptoms of ventricular tachycardia?
- dizziness
- fainting
-sweating - sudden cardiac death
(Brooker et al, 2013)
what is ventricular fibrillation?
- completely disorganised activity in ventricles
- super life threatening!!!!!
- most common cause of cardiac death
- treatment = reboot heart asap
(Brooker et al, 2013)
why does the heart need its valves to work?
- relies on valves to prevent back flow through the chambers and provide unimpeded onward flow of blood to the lungs or body
(Brooker et al, 2013)
what are three valve disorders and what do they do to the heart?
- stenosis - flaps of valve thicken or fuse together which leads to them not opening fully and resisting the normal flow of blood through the body
- regurgitation - valve doesn’t completely close and back flow occurs
- atresia - heart flow has no opening at all
valve disorders are usually either congenital heart disorders or acquired valve disorders
(Brooker et al, 2013)
what valves are associated with the left side of the heart?
Aortic valve - semilunar valve normally with 3 cusps positioned between the left ventricle and the aorta
- the Mitral valve or left atrioventricular valve.
(Brooker et al, 2013)
what will problems can affect the aortic valve?
- aortic stenosis
- aortic regurgitation
(Brooker et al, 2013)
what is aortic stenosis?
blood flow obstruction through valve which results in a pressure gradient between left ventricle and aorta
- increases the work of heart in each systole
- overtime left ventricle compensates by growing larger with thicker walls
(Brooker et al, 2013)
what happens if LV hypertrophy occurs?
- initially okay but overtime the thickening of the ventricular wall reduces it compliance and makes filling the ventricular more difficult during diastole making the heart work harder
- can lead to fibrosis of myocardium, ischaemia, heart failure
(Brooker et al, 2013)
what is the most common form of aortic stenosis?
age related calcification or degeneration of
the valve usually presenting in the 60s to 80s age range
(Brooker et al, 2013)
what is the main treatment for aortic stenosis?
aortic valve replacement
(Brooker et al, 2013)
what is aortic regurgitation?
backflow of blood across the aortic valve during diastole
(Brooker et al, 2013)
what are the main causes of aortic regurgitation?
- rheumatic heart disease
- endocarditis, hypertension and a congenital bicuspid valve.
(Brooker et al, 2013)
what happens to the heart when these is aortic regurgitation?
- Because of the backflow, the LV has an increase in blood volume. - immediate response is an increase in HR and contractility to maintain CO, long term there will be a dilation of the LV with
hypertrophy. - As these adaptations begin to fail there will be a decrease in CO and an increasing back pressure into the pulmonary circulation as well as a reduction in the coronary circulation leading to myocardial ischaemia
(Brooker et al, 2013)
what problems can affect the mitral valve?
- mitral stenosis
- mitral regurgitation
(Brooker et al, 2013)
what is mitral valve stenosis (MVS)?
- narrowing of the mitral valve leading to an obstructed blood flow from the left atrium to the left ventricle creating a pressure gradient back into the LA.
- This damage is either congenital, acquired or rheumatic.
(Brooker et al, 2013)
how would you treat MVS?
- reducing the symptoms of pulmonary congestion and heart failure, slowing the progression of pulmonary hypertension and
control ventricular rate. - Surgical treatment may involve valve replacement or stretching open the valve with a
percutaneous balloon, once the valve has been stretched its function should improve,
but for patients with severe pulmonary hypertension the average survival time is 3
years.
(Brooker et al, 2013)
what is mitral regurgitation?
- back flow from LV to LA caused by damage to the mitral valve
- can be a degenerative change with age as well as rheumatic heart disease
(Brooker et al, 2013)
what valves are on the right side of the heart?
- pulmonary
- tricuspid
(Brooker et al, 2013)
what problems can affect the pulmonary and tricuspid valves?
pulmonary = pulmonary stenosis and pulmonary regurgitation
tricuspid = tricuspid stenosis and tricuspid regurgitation
(Brooker et al, 2013)
why is the left side of the heart at more risk of problems than the right side?
- The right side of the
heart is a relatively low pressure system avoiding high hydrostatic pressures in the respiratory portions of the lungs, if these pressures increase then fluid
would tend to exude into the alveoli and gaseous exchange would be impeded
or fail. - The left side of the heart is a much higher pressure system to drive the blood around the body.
(Brooker et al, 2013)
what is heart failure?
- occurs when heart can no longer effectively pump blood to the rest of the body to meet its demands during normal activity
- has high morbidity and mortality
- end point of majority of heart diseases such as MI, hypertension, valvular heart diseases
(Brooker et al, 2013)
what is stage A of heart failure?
- people with underlying risk factors but no structural abnormality of the heart
(Brooker et al, 2013)
what is stage B of heart failure?
structural abnormalities of the heart, but no symptoms of HF
(Brooker et al, 2013)
what is stage C of heart failure?
have signs and symptoms of HF or asymptomatic when treated optimally
(Brooker et al, 2013)
what is stage D of heart failure?
have signs and symptoms of HF despite being treated optimally
(Brooker et al, 2013)
where in the heart can heart failure take place?
- can happen in left or right side but is typically both
left side
- due to left ventricular dysfunction, this results in a reduction of cardiac output with increasing back pressure into the pulmonary veins and
congestion.
right side
- dysfunction of the right ventricles limiting venous return from the systemic circulation and signs of fluid retention
in the body
(Brooker et al, 2013)
what are factors that affect cardiac function?
- cardiac contractility
- myocardial relaxation
- heart rate and rhythm
- ventricular preload
- ventricular after load
- compensatory mechanisms
(Brooker et al, 2013)
what should nurses consider when caring for patients with heart problems?
- should closely monitor their patients
- should be able to reach by the patient if they have any concerns or questions regarding their problem
- emotional support if its needed
- actively listening to patients
- encouraging healthy habits such as eating better, more exercise, no smoking, no fatty, high in salt foods, lower alcohol consumption
(Lindberg, 2023)
