Learning objectives

To know the consequences of having faulty heart valves

To know that coronary artery disease, heat attacks and changes in blood pressure are dysfunctions of the cardiovascular system

To know the treatment and diagnosis for coronary artery disease, heart attack and a change in blood pressure

Faulty valves Occasionally, valves on the heart do not function

properly This causes several effects of the body:

backflow of blood occurring: If this occurs between the right ventricle and pulmonary

artery then not enough blood gets to the lungs so cant get oxygen

If this occurs between the left ventricle and aorta then not enough oxygenated blood gets to cells

Poor pressure for pumping blood Fainting/collapsing Cold hands and feet Low blood pressure

Dysfunction of the cardiovascular system There are 3 main dysfunctions of the

cardiovascular system: Change in blood pressure Coronary artery disease Heart attack

Changes in Blood Pressure Condition:

Blood pressure is the force exerted by the blood on the walls of the blood vessels

High blood pressure is called HYPERTENSION and this is when the blood pressure significantly greater than the average blood pressure Average : 120 / 80 mm/Hg (millimetres of mercury)

Said as 120 over 80 High blood pressure: 140 / 90 mm/Hg

The top (first) number is the systolic pressure. This is the pressure in the arteries when the heart contracts.

The bottom (second) number is the diastolic pressure. This is the pressure in the arteries when the heart rests between each heartbeat.

Changes in Blood Pressure Condition:

Blood pressure naturally decreases as the blood vessel get smaller E.g. The highest blood pressure is found in the

arteries and the lowest in the veins (capillaries are variable)

Changes in Blood Pressure Causes:

Genetic predisposition (family history of high blood pressure)

Lifestyle: Smoking Alcohol Diet Stress

Symptoms: rarely causes symptoms Severe hypertension can cause:

Headache Sleepiness Confusion Coma

Changes in blood pressure Diagnosis:

Blood pressure monitor – checking of the blood pressure regularly

Treatment: Lifestyle changes:

not smoking drinking less avoiding fatty foods Avoiding foods with lots of salt in

Drugs to: lower blood pressure if it is 140/90 mmHg

or higher. lower your cholesterol level

Questions on coronary artery disease What is the CONDITION coronary

artery disease? List the CAUSES of coronary artery

disease What are the SYMPTOMS? How can it be DIAGNOSED? What TREATMENTS are available? What are the RISK FACTORS?

Coronary artery disease

Condition: A blockage or narrowing of coronary arteries

(the arteries that supply the heart with oxygen and glucose)

This leads to the heart muscle not receiving enough oxygen and a build up of carbon dioxide so it cant respond to exercise demands

Coronary artery disease Causes: the blockages can occur due to several

reasons: Genetic predisposition (family history of high blood

pressure) Lifestyle:

Diet Fat/cholesterol deposits in the arteries from fatty food which

reduces the size of the lumen (space inside the artery) This restricts blood flow therefore blood pressure is increased. This is known as atherosclerosis.

Smoking – increases blood pressure and fat deposits Alcohol – excessive intake increases blood pressure Stress – puts strain on heart making it beat quicker

Coronary artery disease Causes: the blockages can occur due to

several reasons: Age:

fat/cholesterol builds up due to years of eating arteries lose collagen and elasticity causing walls to

become rigid and preventing blood from flowing smoothly.

This increases blood pressure

Coronary artery disease (CAD) Symptoms

Chest pain called angina: dull ache or pressure spreading to the arms

(especially left arm), neck, or back due to blood being force through blockage/narrow part of artery

brought on by exertion e.g. Walking briskly Shortness of breath Indigestion Can be symptomless

Coronary artery disease (CAD) Diagnosis:

By diagnostic imaging so that the heart and blood vessels can be seen Chest X rays – outline of structure can be seen and

changes detected Coronary angiography

patient injected with an opaque medium into the blood

This shows up on X rays so that blood flow can be seen

Better than just x rays as shows soft tissues which normal x rays don’t

Coronary artery disease (CAD) Diagnosis: MRI scan: magnetic resonance imaging

scan of the heart producing high quality images Is used to assess the progress of coronary artery bypass

graft May eventually replace or coronary angiography The patient lies inside a large, cylinder-shaped magnet. Radio waves are sent through the body. This makes nuclei

in the body's atoms move As they move back into place they send out radio waves of

their own. The scanner picks up these signals and a computer turns

them into a picture.

Coronary artery disease (CAD) Diagnosis:

CT scan: CT= computer tomography Take images of a heart beat Good but a long waiting list to have the scan

Coronary artery disease (CAD) Diagnosis: ECG – electrocardiogram

ECG shows the electrical activity of the heart so it shows the pathway starting from atria - SAN, bundle of His, purkinje fibres and finishing at ventricles contracting etc

The electrical impulses are recorded on a piece of paper

A typical trace shows: P wave - atria contracting QRS complex - ventricles contracting T wave – ventricles relaxing

Coronary artery disease (CAD) Diagnosis: ECG – electrocardiogram

Can show lots of different things: Irregular heat beat rhythm – faster

(tachycardia) or slower (bradycardia) than normal

Bigger or smaller time intervals in between waves can indicate heart abnormalities

Can show where a ‘misfire’ occurs Problems with the chambers Problems with thickening of the ventricle

muscle or other heart muscle disorders

Coronary artery disease (CAD)

Diagnosis: Coronary Catheterization (angiogram)

Under local anaesthetic, a small cut is made in a artery to the heart

A liquid dye is injected into the arteries of the heart through a long, thin, flexible tube (catheter) that is threaded through an artery.

The arteries then become visible on X-ray and videotape, showing areas where coronary arteries may be blocked.

The catheter may also be used to push open a blocked artery, a procedure called an angioplasty

Coronary artery disease (CAD) Treatment

Coronary artery bypass graft (CABG) = heart bypass Restores normal function by providing a new route for

blood to flow to the heart bypassing the blocked coronary artery

Procedure: Cut a length of vein usually from the leg Cut at the one end of the blocked coronary artery so that

there is a ‘blockage free’ end Attach one end of the new vein to the cut end to the

‘blockage free’ end of the coronary artery Attach the other end of the new vein to the artery allowing

blood to flow freely

Coronary artery disease (CAD)

Coronary artery disease (CAD) Treatment: CABG

Can sort out more than one blockage and attach more veins e.g. Double heart bypass, triple heart bypass

Advantages Oxygen can get to all parts of heart Heart beat is stronger Pain and angina goes away Live longer

Disadvantages Danger of heart surgery as the patient has to be placed on a heart

lung machine Full function cannot be replaced The graft can rupture – burst open and cause internal bleeding and

death

Coronary artery disease (CAD) Treatment

Lifestyle changes: Healthier diet

avoid fatty foods especially saturated (animal) fat to prevent fat depositing in the coronary arteries and prevention of obesity

Avoid foods with high levels of salt Stop smoking to try to decrease blood pressure

and prevent more fat deposits Limit alcohol intake to help with reducing blood

pressure Avoid stress!

Coronary artery disease (CAD) Risk factors for CAD

Being male Family history Smoking High alcohol intake High levels of fat in the diet High blood pressure Obesity Inactivity

Heart attack Condition:

Heart attack and myocardial infarction are essentially the same

It is when the heart muscle dies and so cannot beat any longer

This means that blood cannot be pumped around the body

Causes: Occurs due to a blockage in the coronary arteries:

Coronary artery disease Coronary thrombosis (blood clot in the coronary artery)

Heart attack Symptoms

Uncomfortable pressure causing chest pain Pain spreading to the shoulders, neck or arms

especially left arm Light headedness, fainting, sweating, nausea or

shortness of breath. Anxiety, nervousness and/or cold, sweaty skin.

Paleness or pallor. Increased or irregular heart rate.

Diagnosis Any technique that diagnoses CAD

Heart attack Treatment

If a major coronary artery is affected then often the patient dies so there is no treatment

However, if it is not a major coronary artery then the patient can be treated and live

Can treat a heart attack by removing the blockage so same treatments as CAD often work

Heart attack Treatment: heart transplant If a major part of the heart muscle has

died or is not functioning properly then the only option would be to replace it

Donor = is the person who has donated the heart (dead!)

Recipient = is the person who is receiving the heart

So the donor heart is put into the recipient

Heart attack Heart transplant procedure:

A donor heart must be found – this must be from an individual who has been pronounced dead

The donor heart must be kept chilled in saline The recipient of the heart has to be tissue-typed to

see if the heart is compatible with them The chest is opened and the patient is placed on a

heart lung machine as most of diseased heart is taken out but all major blood vessels are left intact

The new heart is put in and attached to the major blood vessels

The patient must be put on immunosuppressant drugs to stop the body rejecting the new heart which means that they are susceptible to infection

Heart attack Heart transplant – prevention of

rejection: The patient must be put on

immunosuppressant drugs to stop the body rejecting the new heart

People on immunosuppressant drugs are susceptible to infection as it is stopping the immune system from working properly

If they did not have these drugs then the body would see the new heart as ‘foreign’ and attack and destroy it.

Other Heart Treatments

There are other treatments that can be used for other heart disorders such as misfiring of the heart – irregular heart beats e.g. having a pacemaker fitted.

Heart pacemaker

If the SA node does not function correctly then the heart cannot pump blood efficiently.

The SA node is a pacemaker meaning that it sets the pace of the heart beat and allows it to maintain its rhythm

If this is not functioning correctly then an artificial pacemaker can be fitted

To do this, an insulated wire is put into a major vein with an electrode in the heart muscle itself

The battery end is located just under the skin e.g.. in abdomen or collar bone

Batteries can easily be replaced as easy to get to.

Pacemaker

Detailed treatments for CAD Cholesterol-lowering medications. By decreasing the amount of cholesterol in the

blood, especially LDL (the "bad" form of cholesterol), these drugs decrease the primary material that deposits on the coronary arteries. Examples include statins, niacin, fibrates and bile acid sequestrants.

Aspirin. This common over-the-counter medication may be recommended as an anti-platelet, which thins the blood, and as an anti-coagulant, which reduces the tendency for blood to clot and block a coronary artery, causing a heart attack. Other anti-platelet drugs or anti-coagulants may be prescribed as well.

Beta-blockers. These drugs help make the heart's job of pumping blood easier by relaxing the heart, slowing its rhythm, decreasing blood pressure and lowering the heart's demand for oxygen. They include metoprolol, atenolol and propranolol.

Nitroglycerin. This drug, as a tablet, spray or skin patch, helps relieve chest pain (angina) by opening narrowed blood vessels and improving blood flow to the heart muscle. The patient may also receive nitrates, a longer-lasting form of nitroglycerin.

Calcium channel blockers. These medications help to open coronary arteries to increase blood flow to the heart muscle. They can also help reduce high blood pressure.

ACE inhibitors (angiotensin converting enzyme inhibitors). Similar to beta-blockers, these help lower blood pressure and make the heart's job of pumping blood easier. In addition, ACE inhibitors have shown significant benefits for patients in recovering from a heart attack. They include ramipril, lisinopril, enalapril and captopril.

Vitamins. Folic acid, B-6 and B-12 are vitamins that help to decrease homocysteine in the blood. Homocystiene has been associated with accelerated clogging of the arteries (atherosclerosis). In specific situations, some patients may be prescribed L-arginine or Omega-3 fatty acids.