Annotate your ECG

1. Annotate your ECG

3. Electrocardiogram (ECG) Electrodes are placed on the skin over opposite sides of the heart, and the electrical potentials generated recorded with time. The result is an ECG. P wave = electrical activity during atrial systole QRS complex = electrical activity during ventricular systole T wave = ventricular repolarisation (recovery of ventricular walls) Q-T interval – contraction time (ventricles contracting) T-P interval – filling time – ventricles relaxed and filling with blood Pattern are studied in different conditions and compared to the standard ECG in order to diagnose heart conditions, such as arrythmias and fibrillation. Fibrillation is stopped by passing a strong electric current through the chest wall – the heart stops for up to 5 seconds after which it begins to beat in a controlled way

5. Learning Outcomes • Go through ECG • Analyse the different methods of taking body measurements • Explain the course of events that leads to atherosclerosis • Describe the blood clotting process and its role in cardiovascular disease (CVD) • Know the symptoms of CVD

6. Atherosclerosis – the narrowing of arteries • Leads to coronary vascular disease (CVD) • Fatty deposits block artery or cause clot (thrombosis) to occur • Blockage of coronary arteries causes heart attack (myocardial infarction) • Blockage of arteries supplying brain leads to stroke

7. Causes • Thin endothelium layer of cells on inside of artery becomes damaged e.g. by high blood pressure or cigarette toxins • When lining damaged, large white blood cells move to artery wall and accumulate blood chemicals, especially cholesterol • Fatty deposit builds up - an ATHEROMA

8. Calcium salts and fibrous tissue also build up at site - forms PLAQUE (hard swelling) • Fibrous tissue means artery loses elasticity (hardens) • Plaque causes narrowing of arteries • Difficult for blood to pump – rise in blood pressure • Leads to POSITIVE FEEDBACK (plaque leads to high blood pressure which leads to more plaque) • Oxygen and nutrients can’t get to cells

10. Health measurements • BMI (body mass index) • Need height • Need waist • BMI = Mass kg / height m2 But wait .....

11. A waist to hip ratio of more than 0.95 for men and 0.85 for women is “apple” shape – more PRONE to heart disease Health measurements • Waist/Hip • Measuring tape • To determine the ratio, divide your waist measurement by your hip measurement.

12. Estimating Percent Body Fat • Skinfold measurements: Folds of skin are measured with a caliper. The measurements are used in equations that link the thickness of skinfolds to percent body fat calculations made from more precise experiments.

13. Health measurements • Percentage fat • From skin fold or • Electric impulse • Nowadays a pod can be used

14. Measurements from yesterday ... • BMI • Waist/Hip ratio • Percentage fat • Skin fold callipers So why do we need fat?

15. Essential Fatty Acids • Body cannot synthesise (so need to be supplied in diet) • Fat soluble vitamins (A,D,E and K) only enter our diet in fats • SO fats are essential to our diet to avoid deficiency symptoms e.g. linoleic acid deficiency (scaly skin, hair loss) • Also for .....

16. In cell membranes • Essential for hormones etc.

17. Rearrange these in the correct order

19. Consequences of the atheroma • As the artheroma grows the artery thickens and loses its elasticity. • The diameter of the artery becomes reduced and blood flow becomes restricted resulting in increased blood pressure.

20. Myocardial Infarction • Fatty plaque in artery ruptures • Cholesterol released leading to clot formation • Blood supply to heart blocked • Heart muscle ischaemic (without blood) • Muscles starved of oxygen too long are permanently damaged leading to dead cells • Large area of dead cells more likely to be fatal

21. Stroke • Numbness • Dizziness • Confusion • Slurred speech • Blurred or loss of vision • Paralysis of one side of body

22. Transient Ischaemic Attack • Short lived stroke • Full recovery possible • warning

23. Angina • Chest pain • Heart muscle respires ANAEROBICALLY • Produces lactic acid • Symptoms similar to indigestion

24. Arrhythmia • Heart beats irregularly • Can lead to heart failure

25. Atherosclerosis Summary • Atherosclerosis is the accumulation of fatty material (consisting mainly of cholesterol), fibrous material and calcium forming an atheroma or plaque beneath the endothelium. • As the artheroma grows the artery thickens and loses its elasticity. • The diameter of the artery becomes reduced and blood flow becomes restricted resulting in increased blood pressure. • Atherosclerosis is the root cause of various cardio vascular diseases including angina, heart attack, stroke and peripheral vascular disease.

26. Demonstrate 1. Create a flow diagram for the formation of blood clots 2. Think up a way to remember the chemical changes in the blood • Damage to vessels wall means blood can come into direct contact with collagen in wall • This causes LOADS of chemical changes in the blood: • Soluble plasma protein PROTHROMBIN is converted into THROMBIN (enzyme) • THROMBIN causes soluble plasma protein FIBRINOGEN to form long INSOLUBLE strands of protein FIBRIN • FIBRIN strands form tangled mess that traps blood cells to form a clot

27. Review • Construct a flow chart using words and annotated pictures showing • what happens in atherosclerosis. • Key points in Atherosclerosis: • Endothelial damage • Inflammatory response • Plaque formation • Raised blood pressure • Key points in Blood clotting process: • Conversion of soluble proteins to insoluble protein

28. A T H E R O S C L E R O S I S R T E R Y