The Cardiovascular System Flashcards
Cause of Stroke
Caused by blocked or burst blood vessels in the brain.
- Ischaemic
- Hemorrhagic
Coronary Heart Disease (CHD)
Disease of the blood vessels to the heart, reducing blood supply to the heart muscle.
Myocardial Infarction (MI)
Blood supply to part of the heart is cut off.
Heart Failure
When the heart cannot pump properly to supply the body with sufficient oxygenated blood.
Angina
Chest pains caused by restricted blood supply to the heart muscle.
Rheumatic Heart Disease
Damage to the heart from rheumatic fever.
Arrythmia
Altered heartbeat - can be either faster or slower
Peripheral Arterial Disease
Disease of the arteries in the arms and legs.
Deep Vein Thrombosis (DVT)
Blood clots which form in the legs and can travel to the heart and lungs
Pulmonary Embolism
Blood clots (DVTs) which form in the legs and cause blockages in the heart and lungs.
Atherosclerosis
This is a type of arteriosclerosis that refers to the build-up of fats and cholesterol on the artery walls.
Hypertension
Abnormally high blood pressure. Normally above 140/90.
Ischaemia
An inadequate blood supply to any part of the body.
Function of the Cardiovascular System
To maintain continuous blood flow to and from all body cells to provide nutrients and remove waste.
Components of the Cardiovascular System
- Heart 2. Blood Vessels 3. Blood
Types of Circulation
- Pulmonary circulation - to and from the lungs 2. Systemic circulation - to and from the body
Name the parts of the circulatory system.
Pulmonary Circulation
This is a low pressure system.
Deoxygenated blood enters the heart throgh the Right Atrium –>Right Ventricle–>Pulmonary Arteries–> Lungs
Gas exchange happens in the lungs making the blood oxygenated.
Oxygenated blood leaves the lungs through the Pulmonary Veins–>systemic circulation
Systemic Circulation
This is a high pressure system.
Oxygenated blood leaves the Left Atrium–> Left Ventricle–>Systemic Arteries
Blood reaches body tissues where it becomes deoxygenated
It leaves the body tissues –> Right Atrium–> Pulmonary Circulation
Conducting Cells of the Heart
- SA Node - pacemaker
- AV node - conducts and spreads the electrical impulse
Sino-Atrial (SA) Node
Found in the wall of the right atrium.
Causes atrial contraction.
Impulse spreads from here to both atria.
Identify the SA and AV Nodes.
Atrioventricular (AV) Node
A node of cells located at the base of the right atrium.
Conduct the impulse from the SA with a pause to enable completion of arterial contraction and filling of the ventricles.
Route of electrical conduction in the heart.
- SA Node
- AV Node
- Bundle of HIS
- Right and Left Bundle Branches
- Purkinje Fibers
THE HEART BEATS 2 ATRIA FIRST THEN 2 VENTRICLES.
Systole & Diastole
Systole - period of contraction
Diastole - period of relaxation
Electrocardiogram
Diagnostic tool which evaluates events in the heart via currents generated in body fluids.
Detects:
- Myocardial infarction
- conduction blockages
- arrhythmias
ECG Wave Forms
P wave –> Atrial contraction
QRS complelx –> Ventricle contraction
T Wave –> Ventricle repolarization
Label the parts of an ECG
Coronary arteries (left and right) supply blood to what part of the heart?
The Left and Right ventricles.
What factors determine blood pressure?
- Cardiac output (stroke volume x heart rate)
- Peripheral resistance (vessel length, viscocity and radius)
Factors that Influence Blood Pressure
- Temperature (fever raises heart rate & cardiac output)
- Emotions (anger, fear, anxiety)
- Endocrine system (controlling blood volume)
Peripheral Arterial Disease
A condition in which a build-up of fatty deposits in the arteries restricts blood supply to leg muscles.
Patients who have PAD are at an increased risk of mortality, myocardial infarction and stroke.
Clinical Symptoms of Peripherial Vascular Disease
- Pain, both acute and chronic (intermittent claudication)
- Hair loss to limbs
- Dry shiny skin
- Low skin temperature
- Diminished or absent pedal pulses
- Impotence
- Thick and brittle nails
- Skeletal muscle atrophy
- Ulcers
Advanced Peripheral Vascular Disease can result in:
- Critical Limb Ischaemia
- Necrosis
- Ulceration
- Gangrene
Managment of Peripheral Vascular Disease Includes:
- Smoking cessation
- Promotion of Exercise
- Controlling hypertension, diabetes and cholesterol levels.
- Weight reduction
Patient advice for living with Peripheral Vascular Disease Includes:
- Avoiding tight clothing (TEDS0
- Avoiding direct use of heat (less sensation, susceptible to burns)
- Promoting increased blood supply (warm environment, head elevated)
- Encourage exercise
- Proper foot care (podiatrist)
- Avoiding trauma as healing is difficultt
Pharmacological Treatment for Peripheral Arterial Disease Includes:
- Anti-platelet therapy
- Lipid lowering therapy
- If intermittent claudation is present - an arterial vasodialator should be used.
Surgical Intervention for Peripheral Arterial Disease Includes:
- Angioplasty (insertion of a balloon)
- Embolectomy (surgical removal of an embolus)
- Femoral bypass (implantation of a bypass vein from another part of the body)
- Amputation
Arterioscerosis
- Hardening of the arteries
- Progressive degeneration of arterial walls
- advancing age
- hypertension
- atheroma - fatty plaque
Non-Modifiable Risk Factors for
Cardiovascular Disease
- Male gender
- Increasing age
- Ethnic origin
- Low birth weight
- Genetic predisposition
- Diabetes
- Social deprivation
Modifiable Risk Factors for
Cardiovascular Disease
- Serum cholesterol
- Smoking
- Hypertension
- Obesity
- Lack of physical activity
- Stress
- Alchol intake
- Diet
Stages of Atheroma Development
- Fatty Streak
- Mature Plaque
- Ruptured Plaque
- Thrombus Formation
Describe each step of the blood flow through the heart
- From Superior/Inferior Vena Cava
- Right Atrium
- Tricuspid Valve
- Right Ventricle
- Pulmonary Valve
- Pulmonary Artery
- Lungs
- Pulmonary Vein
- Left Atrium
- Through the mitral valve
- Left Ventricle
- Aortic Valve
- Aorta
- Rest of the body
Mitral Valve
Separates the Left Atrium and Left Ventricle
Aortic Valve
Separates the Left Ventricle and Aorta.
Tricuspid valve
Separates the Right Atrium from the Right Ventricle
Pulmonary Valve
Separates the Right Ventricle and the Pulmonary Artery
Pulmonary Artery
Connects the Right Ventricle with the Lungs
Pulmonary Vein
Connects the lungs with the left atrium.
Aorta
Connects the Left Ventricle with the Body
Which side of the heart has failed in
Shortness of Breath Due to Pulmonary Oedma
Left Heart Failure
Which side of the heart has failed during:
Peripheral Oedema (ankle oedema)?
Right Heart Failure
Congestive Heart Failure
Can be caused by previous heart attack, high blood pressure or coronary artery disease.
These can prevent the heart from efficiently pumping blood to the rest of the body.
This can cause the heart to beat faster increasing the size of the ventricle and decreasing its effectiveness.
This leads to reduced blood flow triggering the kidneys to retain more water and salt causing excess fluid retention.
Compensatory Mechanisms in Congestive Heart Failure
** Sympathetic Nervous Response**
- Lower blood output is sensed by baroreceptors which causes a stimulation of the SA node to increase the heart rate (of an already failing heart).
- Chemoreceptors detect lower oxygen levels due to reduced cardiac output. This triggers the release of adrenaline a vasoconstrictor which increases blood pressure.
Renin-Angiotestin-Aldosterone System
- Reduced renal perfusion triggers water and sodium retention and vasoconstriction. This causes more problems for the heart due to the added fluid in the body.
Ventricular Remodelling
- Due to increased pressure and volume the left ventricle increases the size of myocardial cells and enlarges the ventricle (which further reduces heart function).
Renin
An enzyme in the kidneys released in response to reduced cardiac output.
Converts angiotensinogen (released from the liver) to angiotensin I.
Progression of the Renin Angiotensin Aldeosteron System
- Triggered when there is reduced cardiac output.
- The enzyme renin is released from the kidneys in response to this reduction.
- Renin converts angiotensinogen to angiotensin I.
- Angiotensin I is converted to Angiotensin II by angiotensin converting enzyme as it passes through the lungs.
- Angiotensin II is a powerful vasoconstrictor.
- Angiotensin converting enzyme (ACE) inhibitors therefore prevent to the conversion of angiotensin I to angiotensin II reducing vasoconstriction and blood pressure.
- Angiotensin II also stimulates the release of the hormone aldosterone from the adrenal cortex which promotes sodium and water retention.
ACE (angiotensin converting enzyme) Inhibitors
Used to treat high blood pressure by preventin the conversion of angiotensin I to angiotensin II which reduces vasoconstriction and reduces blood pressure.
Signs and Symptoms of Heart Failure
- Breathlessness
- Oedema
- Weight Gain
- Fatiugue and Lethargy
Orthopnoea
Symptom of Congestive Heart Failure.
Orthopneoa is defined as difficulty in breathing when lying flat.
Increased pressures in the left ventricle results in congestion of the pulmonary veins and resultant leakage of fluid into the alveoli (pulmonary oedema).
Paroxysmal Nocturnal Dyspnoea
Symptom of Congestive Heart Failure.
Paroxysmal nocturnal dyspnoea is when an individual wakes up with sudden and intense difficulty in breathing. This is due to increased left ventricular pressures causing pulmonary congestion.
Ascites
Ascites is a collection of fluid in the abdominal cavity due to right sided heart failure (or biventricular failure) causing systemic congestion.
There may be asociated congestion of the liver.
Severe ascites may cause difficulty in breathing due to pressure on the diaphragm.
Cardiac Cachexia
A condition in later stages of heart failure where there is severe and significant weight loss. This can be due to malabsoprtion as a result of intestinal oedema.
Commonly used medications for Heart Failure
- ACE Inhibitors
- Beta Blocker
- Diuretics
- Digoxin
Diuretics
Increasing diuresis therefore reducing oedema.
ex. Furosemide
Beta Blockers
Reduce the workload of the heart by decreasing heart rate.
Advice for patients living with heart failure
- Avoid alcohol consumption
- Quit smoking
- Reduce salt intake to less than 6g per day to prevent fluid retention.
- Restrict fluid intake (tailored to the individual requirements).
How should patients monitor themselves for signs of oedema?
- Daily weight checks
- Checking ankles
- Reporting weight gain of more than 1.5-2kgs in 2 days
- Consulting with a heart failure nurse specialist.
What advice would you give a heart failure patient in order for them to manage fatigue?
- Importance of medication for heart function
- Spacing activities throughout the day
- Tailored exercise programs (dependent on condition)
HDL
(High Density Lipoproteins)
Good Cholesterol. Delivers cholesterol to the liver.
LDL
(Low density lipoproteins)
BAD Cholesterol. Delivers cholesterol to the body cells. Excess cholesterol is deposited in the arteries.
Hard vs Soft Plaque
Hard Plaque - stable, covered with a thick fibrous cap which is unlikely to rupure
Soft Plaque - unstable, vulnerable to rupture without warning. When it bursts it triggers a thrombosis at the site of rupture which can cause a blockage to the artery.
Angina
Chest pain that occurs when the blood supply to the muscles of the heart is restricted.
It usually happens because the arteries supplying the heart become hardened and narrowed.
It can feel like dull, heavy pain and radiate to left arm, jaw and back.
It is usually triggered by exercise or stress and typicallly lasts for a few minutes.
Treated with GTN (glyceryl trinitrate) spray.
Stable Angina
Attacks occur due to an obvious trigger (such as exercise) and improve with medication and rest
Is not life-threatening on its own. However, it is a serious warning sign that you have an increased risk of life-threatening problems, such as a heart attack or stroke.
Unstable Angina
Attacks are unpredictable, occurring with no obvious trigger and continuing despite resting.
Should be regarded as a medical emergency because it is a sign that the function of your heart has suddenly and rapidly deteriorated, increasing your risk of having a heart attack or stroke.
Beta Blockers
Block the effects of the hormone epinepherine.
Cause the heart to beat more slowly and with less force thereby reducing blood pressure.
Also help vessles to open improving blood flow.
Examples: Atenolol, Bisoprolol, Metoprolol, Nadolol, Propranolol.
Semilunar Heart Valves
Located between:
- left ventricle and the aorta
- right ventricle and the pulmonary artery
Flaps of endocardium and connective tissue reinforced by fibers which prevent the valves from turning inside out.
Atrioventricular Valves
Found between the atrium and ventricles.
Mitral Valve (L) and Tricuspid Valve (R)
Thin structures composed of endocardium and connective tissue that prevent backflow of blood from the ventricle to the atrium.
The typical value of pressure in systemic capillaries is
25mmHg
Hypertrophy
Enlargement of the left ventricle of the heart.
Left-sided Heart Failure
- Reduced Ventricular Function
- Enlargement of the Left Ventricle (hypertrophy)
- Blood not pumped effectively into systemic circulation
- Blood backs up the in lungs.
- Pulmonary congestion
Pulmonary congestion
Accummulation of fluid in the alveoli of the lungs.
Right sided heart failure
- Right ventricular enlargement (hypertrophy)
- Blood is not effectively pumped into the lungs
- Blood backs up in systemic circulation
- Peripheral oedema
- Liver and spleen become congested.
Symptoms of Heart Failure
- Shortness of breath
- Orthopnoea (shortness of breath while lying flat)
- Paroxysmal Nocturnal Dyspnoea (s.o.b and coughing that wakens a person during deep sleep)
- Cough
- Peripheral oedema
- Fatigue
- Abdominal distension
- Palpitations
- Dizziness
- Loss of Appetite
- Cardiac Cachexia (unintentional and severe weightloss)
- Depression & anxiety
Atherosclerosis: Fatty Streak
Origin is uncertain. May be present from childhood.
LDL carries cholesterol and deposits excess into arteries.
Macrophages (white blood cells) ingest LDL to become foam cells encapsulating the fatty streak.
Atherosclerosis: Mature Plaque
Number of foam cells increase.
Area becomes inflamed and plaque forms.
Fibrous camp encloses fatty streek.
Artery narrows and restricts blood floow.
Calcium deposits result in hardening of artery wall.
Atherosclerosis: Plaque Ruptures
Narrowing of the artery lumen
Increased pressure to pump blood through lumen.
Mature plaque ruptures.
Atherosclerosis: Thrombus Development
Platelets are activated to repair ruptured plaque.
Clotting process begins, thrombus forms.
Thrombus can completely block artery.
Thrombosis
Thrombosis is the formation of a blood clot (thrombus) inside a blood vessel, obstructing the flow of blood through the circulatory system.
When a blood vessel is injured, the body uses platelets and fibrin to form a blood clot, because the first step in repairing it (hemostasis) is to prevent loss of blood.
If that mechanism causes too much clotting, and the clot breaks free, an embolus is formed.
Thrombus
Clots that are formed and remain in one area of the body without being carried throughout the bloodstream
Embolus
A blood clot that has formed inside a blood vessel or the heart (a thrombus), and has subsequently broken off and traveled inside the bloodstream to plug another blood vessel, causing organ damage.
Aneurysm
Aa bulge in a blood vessel that’s caused by a weakness in the blood vessel wall, usually where it branches.
Acute Coronary Syndrome
Includes:
- Atherosclerosis
- Obstructions resulting in ischaemia
- Angina (stable/unstable)
- Myocardial Infarction
Angina
Condition in which a blood vessel which supplies the heart becomes partially blocked causing chest pain usually on exertion.
Is treated with GTN (glyceryl trinitrate) spray.
Nursing Care for Angina
- Reducing episodes of chest pain
- Symptom Management
- Patient education on disorder and lifestyle management
- Preventing disease progression
Clincial Presentation of Myocardial Infarction
- Chest Pain
- Nausea/vomiting
- Dyspnoea
- Anxiety
- Cold/Clammy
- Pallor
- Cyanosis
- Temperature
- Decreased Consciousness
Dyspnoea (in MI)
Difficulty breathing.
Damage to the left ventricle in an MI can cause to back up in the lungs resulting in Pulmonary Oedema. There is reduced blood flow to the lungs causing cyanosis and anxiety.
Sympathetic Response to Myocardial Infarction
- Baroreceptors sense drop in cardiac output
- Compensatory Mechanisms –> increased heart rate, vasoconstriction (cool, clammy peripheries & profuse sweating)
Complications of Acute Coronary Syndromes
- Cardiogenic shock
- Arrythmias
- Cardiac Arrest
Investigations for Suspected MI
- 12 Lead ECG
- Check cardiac enzymes for Troponin (released from the heart during MI)
- Full Blood Count
- Urea & electrolytes
- Lipids
- Chest x-ray
Treatment for MI
REPERFUSION THERAPY
- Morphine
- Oxygen
- Nitrates (GTN spray)
- Aspirin
Further treatment via:
Angioplasty and insertion of a Stent
Thrombolysis
Percutaneous Coronary Intervention
Insertion of balloon angioplasty through the femoral artery.
Followed by insertion of a stent to keep the artery open.
Thrombolysis
Dissolves the clot causing the blockage.
Second line treatment
Contraindications present
Benefits must outweigh the risks
Monitor patient for complications
(used when immediate access to hospital care is unavailable)
Pharmalogical Interventions for MI
- Anti-platelet therapy (aspirin, clopidogrel)
- Statins
- Beta Blockers
- Nitrates (GTN)
- ACE Inhibitors
Health Education for a Patient who has had an MI
- Smoking cessation service
- Diet –> 5 a day, reduce salt and saturated fat, increase omega 3 intake
- Optimum BMI
- Exercise/rest
- Optimize diabetic control
- Reduce stress
- Alcohol
- Followup appointments
