Cardiac Physiology Flashcards
Coronary Heart Disease (CHD)
A non communicable disease caused by a build up of fatty acid deposits in the coronary arteries, this restricts blood flow to the heart muscles
Can lead to death if untreated
Symptoms of CHD
Chest pain (angina)
Feeling faint
Nausea
neck, jaw or arm pain
Risk factors for CHD
Smoking
High blood pressure
High cholesterol/ diet with a lot
Lack of exercise
Diabetes
Treating CHD
Blood thinning medication
Statins (cholesterol reducing medication)
Stents (wire mesh that holds open arteries)
Angina
aka as chest pain and is caused as a result of reduced blood flow to the heart muscles.
It’s not usually life threatening but can be a warning sign for heart attacks/ strokes
Heart Attack
reduced blood flow to the heart due to a clot, but it’s still beating
aka myocardial infarction
Cardiac arrest
When the heart stops beating altogether usually caused by diseased electrical systems
Sphygmomanometer
Aka Blood pressure monitor
measures blood pressure by inflating a cuff to restrict blood flow in the arm, it takes a (systolic) reading and then deflates and takes a second (diastolic) reading
Using a sphygmomanometer
The blood pressure cuff goes around the brachial artery. The bottom of the cuff is just above the elbow. while a person is seated in a chair with their feet flat on the floor. Their arm should rest comfortably at heart level.
The cuff inflates to temporarily stop blood flow, and then slowly released. The gauge measures the pressure at both times.
Limitations of a sphygmomanometer
Cuff may be the incorrect size, or not wrapped correctly
Alcohol or caffein may have been taken before the test
Normal blood pressure readings
Normal blood pressure is between 90/60 and 120/80 mmHg.
High blood pressure is above 140/90 mmHg.
Low blood pressure is below 90/60mmHg.
Echocardiogram
An ultrasound scan of the heart to look at the hearts structure and how well it is pumping.
Used to diagnose faulty valves, cardiomyopathy, congenital heart disease
Limitations of echocardiogram
it should be used in conjunction with other tests
Electrocardiogram (ECG)
Places sticky electrodes on the skin around the patients heart, they detect the hearts electrical change in signals
What can an electrocardiogram diagnose?
Arrhythmias (different abnormal heart beats)
CHD
Heart attacks
Cardiomyopathy (hearts walls become thickened/ enlarged)
Resting ECG
Taken for a few minutes whilst the patient is lying down
Stress (exercise) ECG
Carried out whilst the patient takes part in exercise (treadmill or bikes) to see the hearts response to exercise
Ambulatory (portable) ECG
A portable machine worn like a belt to record ECG readings over a day or more.
Segments of an ECG trace
P wave: atrial systole
QRS segment: ventricular contraction
ST segment: represents the delay as ventricles fill up with blood
T wave: electrical reset and repolarisation of the heart
Calculating heart rate from ECG trace
Calculate the number of squares between two R intervals, divide by 300
Bradycardia
Slow heart beat (below 60bpm)
Atrial fibrillation
Baseline irregular (ventricular response is regular)
Tachycardia
Faster heart beat then normal (above 100bpm)
Ventricular fibrillation
Rapid irregular ventricular complexs
