W3 Cardiovascular assessment Flashcards
Superior and Inferior Vena Cava receives:
Returns deoxygenated blood from the systemic circulation
Right Coronary Artery supplies:
Supplies blood to the right atrium (SA node and AV node), right ventricle, the bottom portion of left ventricle and back of septum
Branch of Right Coronary Artery supplies:
Posterior descending artery and right marginal artery
Aorta supplies:
Takes oxygenated blood from the heart into the systemic circulation.
Pulmonary Artery supplies:
Takes deoxygenated blood from the heart to the lungs
Left Coronary Artery breaks off into:
Divides into branches: circumflex artery and left anterior descending artery
Circumflex Artery supplies:
Supplies blood to the left atrium and the side and back of the left ventricle
Left Anterior Descending Artery supplies:
Supplies blood to the front and bottom of left ventricle and the front of the septum
what is included in the assessment and monitoring of heart function?
1) Preload, 2) Contractility, 3) Afterload, 4) Stroke Volume, 5) Central Venous Pressure, 6) Cardiac Output 7) Mean Arterial Pressue
Define Preload:
o Pressure exerted on walls of the ventricle by the volume of blood filling ventricles at the end of diastole.
o Used as an indication of circulatory volume status
Define Contractility:
o The ability of the muscle to shorten and contract when stimulated
o Force of myocardial contraction
Define Afterload
o The pressure the ventricles have to overcome to eject blood
o The resistance to ventricular contraction
Define Stroke Volume
o The volume of blood pumped with each contraction
Define Central Venous Pressure
Pressure measured in the central veins close to the heart and measures preload of the right ventricle
Define Cardiac Output and what is the formula?
o The amount of blood pumped by the heart each minute.
o (stroke volume X heart rate)
Define Mean Arterial Pressure (MAP) and what is the formula?
Average pressure in the patient’s arteries during one cardiac cycle
(Diastolic X 2) + Systolic / 3
What regulates/impacts stroke volume?
Preload
Afterload
Contractility
what regulates cardiac output?
stroke volume and heart rate
what increases preload?
o Alterations in afterload:
increased afterload, high blood pressure or faulty heart valves increases preload because more blood stays in the heart after it pumps
o Decreased Heart Rhythm
slower the heart, the more time the heart has to fill
what decreases preload?
1) Low blood volume (hypovolaemia)
2) Increased intrathoracic pressure
3) Increased intracardiac pressure (temponade- Drain)
4) Decreased venous blood pressure/return
5) Atrial arrhythmia (AF)
what increases afterload?
1) increased vascular resistance
2) Hypertension:
* because left ventricle has to work harder to pump blood out of the aorta. The aortic valve won’t open until the left ventricle pressure is higher than the systemic blood pressure.
3) Aortic stenosis and regurgitation
4) Hypothermia (vasoconstriction)
What decreases afterload?
1) Hypovolaemia
2) Mitral valve regurgitation
3) Hyperthermia (vasodilation)
What decreased heart contractility?
Hypoxia/hypoxaemia
Ischaemia
Drugs: calcium channel blockers, thiopentone
Does Oxygen “Increase” or “Decrease” contractility?
Increases contractility
This increases oxygen demand and work load on heart
Sympathetic stimulation ________ HR by Stimulating ___ and ___ node and cardiac muscles during ________ and _________ stress
Sympathetic stimulation Increases HR by Stimulating SA and AV node and cardiac muscles during emotional or physical stress
what does parasympathetic stimulation do to heart rate?
Decreases heart rate
Via vagus nerve
How is Cardiac output assessed?
- Heart rate and rhythm monitoring with continuous
cardiac monitoring - Feel pulses,
- Auscultate heart sounds for S1 & S2.
- Haemodynamic monitoring (invasive and/or non-
invasive)
o TPR, BP SPo2 and UO (>0.5ml/kg/hr)
o Invasive intra-arterial pressure (continuous BP
monitoring)
o Central venous pressure
o Pulmonary artery pressure
o Thermodilation cardiac output (measure the time it takes for ventricle to change dimension when a cool substance is ejected into the heart blood- this provides a measurement of stroke volume)
What is Haemodynamic monitoring?
Measures the blood pressure from inside the veins, heart and arteries, it also measures flood flow and how much oxygen is in the blood
what are the two types of haemodynamic monitoring?
Invasive (catheter) and Non invasive (BP cuff, obs, urine output, inspection)
list the different haemodynamic monitoring measurements:
- Arterial pressure
- Mean arterial pressure
- Cardiac monitoring
- Central venous pressure (preload of R ventricle)
- Left and right ventricular pressure
- pulmonary artery wedge
- Left Atrial Pressure
- Aortic pressure (aneurysm)
How is preload measured?
- Central Venous Pressure
- Pulmonary artery pressure
- Pulmonary capillary wedge pressure (catheter with an inflated balloon is wedged into the small pulmonary arterial branch. Provides a measurement of the end diastolic pressure in the left ventricle).
Non-invasive assessment of cardiac output includes:
Look, Listen, Feel- IPPA
- Inspect:
o Skin colour, temperature, cap refill, mucous membranes, GCS - Check pulses:
o (Invasive and Non-invasive) Rate, Rhythm, strength and equality. Difference between central and peripheral pulses - Urine output:
o > 0.5ml/kg/hour
