13.2 Assessing cardiac function_2025_slides.pdf
- 1. PHTY254 Assessing cardiac function Dr Sarah Rhodes
- 2. Session objectives By the end of this module, the student should be able to: 1.Assess the following: - Heart rate and rhythm - Oxygen saturation - Blood pressure - Peripheral pulses 2. Interpret the findings and analyse them relative to normal values 3. Explain the key features of common cardiac conditions
- 5. Factors that affect HR variability - Posture - Level of fitness - Physical activity - Stress/anxiety - Relaxation - Sleep - Stimulants - Heart damage/disease - Medications - Metabolic causes
- 6. Exercise and Heart Rate CO = SV x HR CO = Cardiac Output (L/min); SV = stroke volume HR increases with exercise; level of increase is determined by level of fitness and intensity of exercise The fitter you are, the more effective your heart is at pumping blood each contraction; therefore HR lower at any given intensity
- 7. Measuring heart rate • Radial or brachial pulse • Auscultation • Heart rate monitor
- 8. Why assess HR? • Determine target heart rate for training purposes • Establish baseline level • Determine any deviation from normal • Safety!
- 9. Heart rhythm • The cardiac cycle • Key features of a normal ECG • Factors that contribute to changes in heart rhythm • Common variations in heart rhythm • Clinical rationale for assessment of heart rhythm
- 11. Normal ECG
- 12. Factors that contribute to changes in heart rhythm • Heart disease • Damage to heart muscle • Electrolyte imbalance • Recovery from heart surgery
- 13. Symptoms of heart rhythm irregularity • Palpitations • Dizziness or light-headedness • Syncope • SOB • Chest pain or tightness • Fatigue/tiredness • MAY BE ASYMPTOMATIC Source: dailyplateofcrazy.com
- 14. Assessment of heart rhythm • Observe patient • Radial pulse check • Arterial line • ECG • Holter monitor • Exercise tolerance test (ETT) Source: img.webmd.com
- 15. Why assess heart rhythm? • Determination of heart rhythm prior to treatment (baseline) • To establish if there is an abnormal rhythm (arrhythmia) • Risk assessment and follow-up
- 16. Common variations in heart rhythm: atrial • Atrial Fibrillation (AF) • Atrial Flutter • Premature atrial contractions (PACs) • Supraventricular tachycardia (SVT) AHA’s Interactive Cardiovascular library: https://watchlearnlive.heart. org/CVML_Mobile.php?mod uleSelect=arrhyt
- 17. Common variations in heart rhythm: ventricular • Most common are premature ventricular contractions (PVCs) • Ventricular arrhythmias CAN BE FATAL • Ventricular Tachycardia (rate 101-250bpm) • Ventricular Fibrillation
- 18. Oxygen saturation - Oxygen Dissociation Curve
- 19. Measurement of oxygen saturation • What is normal range? • Why assess it? • Abnormal values – what to look for • Factors affecting accuracy of the reading
- 20. Blood pressure • Explanation of normal systolic and diastolic readings • Age related changes across the lifespan • Factors that contribute to normal BP variability • Measurement of blood pressure • Classification of hypertension and risk factors • Clinical rationale for assessment of BP
- 21. Systolic and diastolic BP Systolic blood pressure — indicates the maximum arterial pressure during contraction of the left ventricle Diastolic blood pressure — indicates the pressure in the arteries when the heart rests between contractions
- 23. Measuring blood pressure • Manual sphygmomanometer • Automatic sphygmomanometer • Arterial line
- 24. Mean arterial pressure (MAP) • MAP is the average blood pressure throughout one complete cardiac cycle • Formula: MAP = DP + 1/3(SP-DP) OR SBP+2(DBP)/3 • Normal range = 65-110mmHg • Usually monitored invasively via arterial line • Monitored to ensure adequate perfusion of vital organs Source:Radial_compression_device_3.jpeg (1152×918)
- 25. Variations in resting blood pressure • Sleep/relaxation • Emotional stimuli. E.g. stress, excitement • Environmental factors. E.g. temperature • Medications • Caffeine
- 26. Non-modifiable risk factors for high blood pressure (hypertension) • Age • Sex • Ethnicity • Family history
- 28. Modifiable risk factors for hypertension (HTN) • Risk factors include: • Smoking • High salt diet • Physical inactivity • Obesity • Excessive alcohol • Obstructive sleep apnoea (OSA) • Insufficient/poor quality sleep • Stress
- 29. Classification of blood pressure BLOOD PRESSURE CATEGORY SYSTOLIC mm Hg (upper number) DIASTOLIC mm Hg (lower number) NORMAL LESS THAN 120 and LESS THAN 80 ELEVATED 120 – 129 and LESS THAN 80 HIGH BLOOD PRESSURE (HYPERTENSION) STAGE 1 130 – 139 or 80 – 89 HIGH BLOOD PRESSURE (HYPERTENSION) STAGE 2 140 OR HIGHER or 90 OR HIGHER HYPERTENSIVE CRISIS (consult your doctor immediately) HIGHER THAN 180 and/or HIGHER THAN 120
- 30. Why measure blood pressure? • Risk assessment • Determination of baseline level Source: opendemocracy.net
- 31. Blood pressure and exercise Blood pressure level General ability to be more active Below 90/60 You may have low blood pressure, speak to your doctor or nurse before starting any new exercise 90/60-140/90 It is safe to be more active, and it will help to keep your blood pressure in this ideal blood pressure range 140/90 – 179/99 It should be safe to start increasing your physical activity to help lower your high blood pressure 180/100 – 199/109 Speak to your doctor or nurse before starting any new exercise 200/110 or above Do not start any new activity – speak to your doctor or nurse
- 32. Assessment of peripheral pulses • Used to determine signs of peripheral arterial disease (PAD) • Observation • Palpation • Capillary refill • Arterial pulses Source: commons.Wikimedia.org
- 33. Peripheral pulses: where to find them
- 34. Examination of peripheral pulses Which and what order? Where and how? 1. Radial artery • Radial side of wrist. • With tips of index and middle fingers. 2. Brachial artery • Medial border of humerus at elbow medial to biceps tendon. • Either with thumb of examiner's right hand or index and middle of left hand. 3. Carotid artery • Press examiner's left thumb against patient's larynx. • Press back to feel carotid artery against precervical muscles. • Alternatively from behind, curling fingers around side of neck. 4. Femoral artery • Patient lying flat and undressed. • Place finger directly above pubic ramus and midway between pubic tubercle and anterior superior iliac spine. 5. Popliteal artery • Deep within the popliteal fossa. • Compress against posterior of distal femur with knee slightly flexed. 6. Dorsalis pedis (DP) and tibialis posterior (TP) arteries (foot) • Lateral to extensor hallucis longus (DP). • Posterior to medial malleolus (TP).
- 35. Pulses in the foot • Posterior Tibial: To palpate pulse, place fingers behind and slightly below the medial malleolus of the ankle. • Dorsalis Pedis: To palpate pulse, place fingers just lateral to the extensor tendon of the great toe.
- 36. Common cardiovascular conditions • Hypertension • Coronary artery disease • Myocardial infarction • Stroke • Heart failure • Arrhythmias • Heart valve disease
- 37. Ischaemic Heart Disease (IHD) Aetiology • Decreased myocardial perfusion • Atherosclerosis of coronary arteries Signs & Symptoms • Angina • SOB • Sweating/nausea • Myocardial infarction (MI) Source:ecgguru.com
- 38. Cardiac valve disease Two types (or combination of both): stenosis and regurgitation Stenosis: incomplete opening of valve →increased pressure and volume of blood due to backing up Regurgitation: incomplete closure of valve → blood leaks back through valve rather than movement in a single direction, so heart has to work harder Causes: CHD; rheumatic fever; aging; endocarditis Signs & Symptoms: heart murmur; SOB; swelling; chest pain; light- headedness
- 39. Cardiomyopathy • Enlargement, thickening and stiffness of the heart muscle • Can be inherited or acquired • Signs and symptoms including SOB; swelling of ankles, legs, feet and abdomen; dizziness; light-headedness; chest pain; heart murmurs; arrhythmias • Can lead to heart failure
- 40. Heart failure • Impaired systolic function • Reduced cardiac output • ↓ left ventricular ejection fraction (LVEF) • Ventricular remodelling • Signs and symptoms: SOB, fatigue, reduced exercise capacity Source: Wikipedia.org
- 41. To sum up: • There are various measures of assessment of cardiac function • Together they provide an overall picture of a patient’s CV status • Comprehensive assessment of CV function is important to: - obtain a baseline measurement - to recognise any deviation from normal - to ensure patient safety