Cardiovascular system Flashcards
What is angina?
The mismatch between oxygenated blood and myocardial demand.
What are the 3 types of angina?
- Stable- relieved at rest
- Unstable- A type of ACS and it’s not relived at rest.
- Prizmetal- A type of coronary spasm due to sympathomimetics like cocaine or cannabis.
What is an MI?
- A myocardial infarction is when there is a lack of blood flow and oxygen to the heart. It’s essentially a heart attack and may lead to the arteries becoming blocked/occluded.
- When coronary blood flow is occluded as a result of a blood clot or fatty deposits for a prolonged period, death of myocardium will occur.
Who is at a greater risk of developing an MI and why?
- Pts who have vascular diseases such as atherosclerosis as the arteries narrow and restrict blood flow to the tissues.
- Pts who have had a previous heart attack/stroke
- Smokers because the nicotine in cigarettes causes arteries to narrow.
- Excessive alcohol intake as this increases the level of LDL proteins.
- FXH of an MI
- Misuse of drugs like cocaine.
- > 40
What is atherosclerosis?
- It’s when there is an accumulation of plaque made up of fatty deposits and lipid-loaded macrophages.
- It causes arteries to harden, lose elasticity, and become narrower.
What happens during an MI?
- 0-24hrs following an infarction, the pt is likely to develop cardiogenic shocks and arrhythmias.
-1-3 days after, tissue around the infarcted site becomes inflamed and flooded with neutrophils leading to pericarditis.
-3-14 days after, this is when macrophages invade the tissue and the healing process begins with the formation of scar tissue.
- 2 weeks - months later, cardiac tissue scarring finishes with the formation of grey tissue. The remaining muscle grows/ changes shape.
Signs & symptoms of an MI:
- Central crushing chest pain
- Rapid irregular pulse
- Hypotension
- Dyspnoea
- Fatigue
- Sleep disturbances
- Diaphoresis
- Signs of shock
- Cyanosis
What is heart failure?
- A general term used to describe several cardiac conditions that lead to poor perfusion of tissue.
- It’s often associated with systolic and diastolic congestion with myocardial weakness.
- This weakness impairs the ability of the heart to pump efficiently.
- In acute heart failure, there is a sudden decrease in the amount of blood pumped out from both ventricles leading to a reduction in o2 to tissues.
Is the progression of chronic heart failure gradual or quick?
It’s a gradual progression and no symptoms in the early stages.
What’s an LVAD?
- A left ventricular assist device is given to pts on the transplant list and are at risk of death without it.
- It is a mechanical pump that is inserted into the left ventricle.
- There is no measurable pulse or blood pressure.
- LVAD failure is life-threatening as it results in retrograde blood flow as the valves don’t stop regurgitation.
Pathophysiology of an MI:
-An occluded coronary artery results in myocardial ischaemia due to a lack of oxygen to the cells.
- If o2 is deprived for more than 20-45 mins, it can lead to necrosis. (cell death)
-The extent of the ischaemia depends on the extent of the occlusion.
- when the infarct has taken place, collagen scar forms and the damaged muscle does not contract efficiently.
- As a result it conducts electrical signals much slower, resulting in inefficient contraction of the myocardium.
Pathophysiology or RHF:
- It’s a pumping dysfunction. The ventricles aren’t able to pump blood into the pulmonary arteries leading to the lungs.
- This causes an increase in the volume in the right atria causing an increase in BP and pressure in the systemic venous system.
- This leads to an accumulation of blood in some major organs leading to an enlargement of the (liver, kidney & spleen ).
Signs and symptoms of RHF:
- Pitting oedema to the sacrum/feet
- Enlargement of organs (splenomegaly)
- Pleural effusion due to an increase in capillary pressure
- Distended jugular veins
- Breathing difficulties due to ascites
-Fatigue - Jaundice due to liver damage
Pathophysiology of LHF:
- The contraction of the left ventricle is ineffective and it cannot pump out all the blood it receives from the left atrium.
- This results in pooling of the blood in the left atrium and raised pressure in the pulmonary veins leading to pulmonary oedema.
- As a result of the oedema, pts may experience dyspnoea, orthopnoea, productive cough, frothy sputum & pallor.
- Left ventricle failure also results in poor cardiac output.
- As cardiac output decreases, perfusion to the tissues diminishes resulting in poor o2 delivery.
Signs and symptoms of LHF:
-Dyspnoea in the early stages due to fluid accumulation in the pulmonary capillary bed.
- Dizziness, fatigue & weakness due to poor oxygenation of the body tissues resulting in low cardiac output.
- Orthopnoea due to DIB whilst supine.
- Productive cough with frothy sputum
- Wheeze due to bronchospasm
- Crackles at the base of the lung due to pulmonary oedema
- Cyanosis
- Tachycardia
