Review Lecture Flashcards
Why is chest pain in a patient with stable angina brought on by exercise?
Blood flow to left coronary artery is reduced since diastole is shorter and diastole is when the left coronary artery fills the most
What is the primary mechanism by which GTN (glyceryl trinitrate) spray alleviates myocardial infarction in a patient with stable angina?
Dilation of systemic veins
This means that less blood fills the heart
Reducing the demand on the heart so it needs less O2
How can B blockers help with myocardial infarction?
Slows heart rate
More time in diastole so can fill with blood more
Reduces demand on heart
What are the 3 type so acute coronary syndromes going from least severe to most severe?
What causes the acute coronary syndromes?
Unstable angina
NSTEMI
STEMI
Caused by a plaque rupturing
Where may the pain of myocardial infarction radiate to?
Severe central crushing chest pain
May raider to neck, left shoulder and arm
If somebody has had a full thickness myocardial infarction. What will be present in there ECG weeks later indicating they’ve had an MI?
PATHOLOGICAL Q wave
If theres a sign of a STEMI with ST elevation in leads II, III and AvF which coronary artery is likely affected?
What view of the heart is being looked at?
Right coronary artery
Inferior view
Which side of the heart is lateral?
What group of ECG leads would ST elevation be present in a lateral infarct?
Left side of heart
Leads I, aVL, V5, V6
What findings would you have in an Acute anterolateral NSTEMI?
So what leads do you see a change?
What is the change?
Do you see troponin?
ST depression in leads I, AvL, V3, V4, V5 and V6 and presence of Troponin
What are the cardiac specific isoforms of troponin?
Troponin I and Troponin T
What is the function of Troponin?
Regulates skeletal and cardiac muscle contraction
What causes HFrEF (Reduced ejection fraction in heart failure)?
Systolic dysfunction inability to contract properly
What causes heart failure where the ejection fracture is preserved?
HFpEF
Diastolic dysfunction
Cant fill properly
Due to remodelling
Hypertrophy of LV has made it stiff
If a patient has an EDV of 120ml in their LV and an End Systolic Volume is 80ml what is her ejection fraction as a percentage?
120 - 80 = 40ml
40/120 = 0.33
Ejection fraction = 33%
If both ventricle of the heart fail what is this reffered to as?
Congestive heart failure
What can cause left ventricular failure?
Previous MI
Vol overload due to mitral or aortic valve regurgitation
Dilated cardiomyopathy
Chronic hypertension
Severe aortic stenosis
What can cause right ventricular failure?
LV failure, therefore then leading to congestive heart failure
Secondary to chronic lung disease (pulmonary hypertension)
Pulmanroy valve stenosis
How does hypoxia affect vessels in the lungs?
Vasoconstriction of the blood vessels leading to the blood being diverted from the hypoxia areas of the lungs
This leads to pulmonary hypertension
In congestive heart failure, why does pulmonary oedema occur?
Why?
Increased hydrostatic pressure in the pulmonary capillaries
This is due to blood harder to fill into left side of heart
So increased blood in left atria then increased pressure in pulmonary veins
If a patient has heart failure and has developed pulmonary oedema and is already taking an ACE inhibitor, what type of drug will be given to help alleviate the oedema and reduce the workload of the heart?
What is an example of this drug?
Loop diuretic
Furosemide
What does aldosterone?
Promotes Na+ and water reuptake in the kidneys
If someone has been stabbed in the groin and is in Hypovolaemic shock, what is the state of their:
Arterial Blood Pressure (aBP)?
Central Venous Pressure (CVP)?
Peripheral Resistnace (TPR)?
aBP decreased
CVP decreased
TPR increased (wants to preserve aBP so vasoconstriction)
What is the equation that relates mean arterial blood pressure, to heart rate, stroke volume and total peripheral resistance?
maBP = HR x SV x TPR
Since HR x SV = CO
Equation for maBP is
maBP = CO x TPR
What is thee equation for mean arterial blood pressure?
maBP = CO x TPR
Where does the jugular vein drain into?
Superior vena cava (SVC) into the right side of the heart
Why would cardiac output be reduced with a pulmonary embolism?
Blood supply to the left side of the heart reduced
