Describe the purpose of the Aortic Valve
It ensures that oxygenated blood flows in the correct direction from the heart to the rest of the body, preventing it from flowing back into the left ventricle.
Where are the pulmonic, aortic, tricuspid and mitral valves located?
Pulmonic valve = between the right ventricle and the pulmonary artery.
Aortic valve = between the left ventricle and the aorta.
Tricuspid valve = between the right atrium and the right ventricle.
Mitral valve = between the left atrium and the left ventricle.
Describe a typical ECG trace.
P wave = atrial depolarisation
QRS = ventricular depolarisation
T Wave = ventricular repolarisation
Describe the 4 stages of blood flow.
- Deoxygenated blood leaves right ventricle via pulmonary artery → lung
- Picks up O2 at lung, and oxygenated blood returns to left atrium of the heart, via the pulmonary vein
- Oxygenated blood pumped out of left ventricle of heart via aorta → delivers oxygen to the body
- Deoxygenated blood returns to the right atrium via the vena cava.
Describe the difference between depolarisation and repolarisation.
Depolarisation is the process by which the membrane potential becomes less negative, facilitating the generation of an action potential whereas repolarisation is the process of restoring the cell membrane to its resting electrical potential after it has been depolarised. Sodium and potassium are the primary ions responsible for changes in the electrical current.
Describe the location and purpose of coronary arteries.
The coronary arteries are located on the outer surface of the heart, wrapping around it to supply the heart muscle with blood (main blood supply). They branch off the aorta and travel along the coronary sulcus (groove) on the heart’s surface.
What is the heart’s natural pacemaker?
The sinoatrial node.
Describe the typical therapy input post cardiac surgery.
Day 0-1: CICU or CHDU seen by physios and ?EMP (early mobilisation project) (mobility, education around mindful movements).
Day 2-3: Stay on CHDU or move to wards.
Day 4: attachment removal (typically) if mobilising independently by this point, can be discharged.
Day 5: typical aim for discharge by this point - if someone is not MOFD, it is likely due to comorbidities.
Describe what the epicardial wires (EPW/pacing box) do, example 80DDD
Number = Minimum heart rate (usually 80-90bpm).
1st Letter = is what it is sensing (Atria, Ventricle, Dual).
2nd letter = is where the cardiac pacing is occurring (A, V, D).
3rd letter = is I, T or D, I = inhibit [does nothing as heart is working], D = dual, inhibiting and T = triggering [box is doing all the work])
Combination of letters that wouldn’t show = If there is Dual present, can be DDD or DDI , never anything else.
Define Atrial Fibrillation (AF).
Atrial fibrillation is a condition that causes an irregular and often fast heartbeat due to the atria not filling up properly. It’s not clear what causes atrial fibrillation, but it’s common in people with other heart conditions.
Describe Heart Failure (HF).
Heart failure means that the heart is unable to pump blood around the body properly due to things like heart disease and high blood pressure. It usually happens because the heart has become too weak or stiff. It can cause leg oedema (swelling) because blood backs up in the veins, particularly in the legs, due to poor circulation. This backup leads to fluid accumulating in the surrounding tissues, causing swelling in the legs, ankles, and feet.
Describe Coronary Artery Disease
Coronary artery disease (CAD): also known as coronary heart disease or ischemic heart disease, is a condition where the coronary arteries that supply blood to the heart become narrowed due to a buildup of plaque. This narrowing restricts blood flow to the heart, potentially leading to chest pain, shortness of breath, and, in severe cases, heart attacks.
Why can cardiac arrests cause brain injuries (stroke, HPI)?
During a cardiac arrest, blood flow to the brain is significantly reduced or stopped, leading to a lack of oxygen and potential brain damage. This can cause brain cells to die, potentially resulting in stroke symptoms or a stroke.
Why can cardiac surgeries cause brain injuries such as a stroke?
During surgery, manipulation of the ascending aorta can dislodge plaque (atheromatous debris) that travels to the brain and blocks a blood vessel, causing a stroke.
Other factors include:
- Hypo-perfusion (reduced blood flow)
- AF increase risk of blood clots
- Pre-existing conditions (Carotid Artery Stenosis, Cerebral Vascular Disease).
What is a CABG?
Coronary Artery Bypass Grafting - During surgery, a new blood vessel, often taken from the leg (saphenous vein) or chest (internal mammary artery), or radial artery (forearm) is grafted onto the coronary artery above and below the blockage, creating a new pathway for blood flow. (Left anterior coronary artery is the main concern)
What are AVR/MVRs?
Aortic or Mitral Valve Replacements or repairs - these are performed due to conditions like stenosis (narrowing) or regurgitation (leakage).
What are the differences between mechanical and biological valve replacements?
Mechanical replacements require blood thinners for life and can hear ticking but typically last longer whereas biological replacements don’t necessarily need blood thinners and last for less time but sufficient for older patients but no noise.
What is a TAVI?
Transcatheter aortic valve implantation is a minimally invasive option for certain patients for aortic stenosis. (insert valve using a catheter through the groin).
What are AAR/ARRs?
Aortic Root Replacements and Aortic Arch Replacements or repairs are where an aortic aneurysm removed, then a tubular grip is attached to contain size of walls (part of aorta is ballooning). If able to, the human valve is returned, if not then the valve is replaced as well.
What is a Valvuloplasty?
A surgery used if patients are at too high risk for AVR, via catheter, inflate balloon to create space for valve.
What is an Aortic dissection?
These are tears either Type A, ascending aorta closest connection to heart or Type B, descending further away from heart (could be treated by vascular team). The teared area is removed and replaced with a segment of artificial vessel wall (graft).
What is a Maze?
Used to treat AF, open or closed surgery (mini-maze) that creates small incisions on left and right atrium to disrupt abnormal electrical impulse - this is done when other treatments haven’t worked.
What is mindful movement?
‘Let pain be your guide.’
Non-loading activities = can complete at normal, just listen to your body.
Loading activities = Imagine a tube going around your body, complete movements without going outside the tube e.g., avoid upper limb abduction, hip flexion.
What precautions are taken following the insertion of a permanent pacemaker (PPM)?
Restrict movements such as pushing and pulling, not to lift anything heavier than 2kg, not to weight bear through left arm and not to life arm past 90 degrees.
