Cardiovascular System Flashcards
Layers of the heart
Pericardium- protective outer sac layer, pericardial fluid (2 layers)
Epicardium- visceral layer of serous pericardium
Myocardium- middle layer, largest portion of heart wall, contains contractile fibres/conduction system/blood supply, site of MI
Endocardium- innermost layer, smooth muscle, lines valves/ inner chambers of heart
Where is the tricuspid valve?
Right atrioventricular valve
Mitral valve location?
Left atrioventricular valve
Electrical pathway of heart
SA node- AV node- bundle of his- bundle branches- purkinje fibres
What heart sounds are you listening for ?
Lub, dub
Lub= atrioventricular valve closing
Dub= semilunar valve closing
Stroke volume?
Volume of blood pumped by each ventricle in 1 contraction
(Approx 70ml)
Cardiac output
Amount of blood pumped out of the heart in one minute
Stroke volume X Heart rate
Aetiology/ causes of cardiovascular conditions
Genetics
Age
Smoking
Exercise
Drug/alcohol use
Hypertension
Stress
Type 2 diabetes
MI/ ischaemia
Chest trauma/ injury
Infection
Atherosclerosis
Build up of plaque/fat/lipids in arteries (atheroma)
Reduced blood flow
Harden over time, pierce artery wall and reduce elasticity, scar tissue formed
Increases blood pressure
Possible plaque rupture/thrombosis
Consequences of atherosclerosis
Ischaemia due to narrowed blood vessel
Complete occlusion= infarction
Blood vessels rupture
Congestive heart failure
Later stage of heart failure- weak pump function of ventricles due to thickening/smaller filling capacity
(Congestion of fluid in body due to poor circulation)
Preload
Volume of blood in ventricles at the end of diastole
After load
Resistance the left ventricle must overcome to circulate blood
Symptoms of heart failure
Peripheral oedema/ swelling in extremities
SOB
Chest pain
Dizziness, fatigue
Heart palpitations
Dry hacking cough
Cardiac output equation
Stroke volume X heart rate
Blood pressure equation
Cardiac output X systemic vascular resistance
Left sided ventricular failure vs right
Left:
-pulmonary oedema
-inability for heart to pump out all oxygenated blood from lungs
-air mixes with plasma forming white frothy foam
Right:
-peripheral oedema in legs/ankles/
-build up of fluid in systemic circulation
Consequences of LVF
Cyanosis
SOB/ DIB, Rhonda, wheeze, resp distress
Coughing white/pink sputum
Jugular vein distension
Infection
Ischaemia
Chest pain
Confusion
High bp/tachycardia (compensatory)
Orthopnoea
Causes of heart failure
Infection
Chest trauma
MI/ ischaemia
Cardiomyopathy (disease of heart muscle)
Pulmonary disease
Tricuspid/pulmonary valve disease
Heart failure medications
Diuretics- encourage fluid drainage (oedema), reduces hypertension
Ace inhibitors- lower bp, reduce strain on heart
Ischaemic heart disease + symptoms
-Reduced blood supply to heart
-caused by atherosclerosis of coronary arteries
-prolonged ischaemia= necrosis, MI
-increased lactic acid in blood from anaerobic respiration of ischaemic tissue
Symptoms:
Left shoulder/arm pain, angina
Cardiomyopathy
-disease of myocardium (muscle layer of heart), weakens, unable to pump efficiently
Types of cardiomyopathy
-dilated
-hypertrophic
-arrythmogenic right ventricular dysplasia
-restrictive cardiomyopathy
(Differ on How the heart muscle is damaged)
Cardiomyopathy leads to…?
Irregular heart beat
Heart failure
Heart valve issues
Aneurysm
Ballooning of blood vessel wall due to high bp
Can burst/rupture blood vessels
Common in aorta
Causes of aneurysm
Congenital
Trauma
Infection
Atherosclerosis
(Causing high bp)
Types of aneurysm
Fusiform- artery wall expands until it bursts
Dissecting- split of inner lining, blood filters through and strips layers apart, more blood around artery than in it, occurs in high pressure areas eg aorta
Saccular- artery wall forms a sac
Complications of aneurysm
Stroke- clot travels to brain
Thromboembolism
Angina
Low Bp, tachycardia, light headedness
Varying Bp readings
Sudden extreme headache (subarachnoid haemorrhage)
Abdominal aortic aneurysm
Caused by atherosclerosis/genetics/smoking
Most Common over age 50
Aortic dissection (result of AAA)
Inner layer of aorta tears, haemorrhage into vessel wall
Acute and life threatening
Symptoms of AAA/ dissection
Pain in anterior chest/back, tearing pain
Syncope/Transient LOC
Hemiplegia (one sided paralysis)
Pulsating mass
Low bp
Hypertension
High bp, 2 types:
-essential
-secondary
Affects kidneys
Essential hypertension
Unknown cause, 95% of cases, asymptomatic
Secondary hypertension
Caused by medical conditions:
Alcohol, obesity, pregnancy, drug treatment, hyperthyroidism, kidney disease, adrenal gland disorders
Hypotension
Low bp, inadequate blood supply to organs
Complication of other conditions
Eg postural hypotension, POTS, vasovagal syncope, Hypovolaemia, infection (loss of fluid)
