PBL

ECG

100

Why is the T wave an upwards deflection?

Heart has depolarised, so it must re-polarise. Back to the resting negative membrane potential -90mv. It is therefore negative. It is then flowing - to - which = +

200

Why is the left bundle branch of the bundle of His so important?

it conducts electrical impulses to the left ventricle and also helps with a little bit of innervation

300

Which lead gives the best view of the inferior wall of the heart

 I, II, avF

400

If an AP is running up a muscle perpendicular and crosses the axis which is horizontal, what will it read on the ECG and why?

Isoelectric as it has the same amplitude on either side of the axis as they are cancelled out.

500

Walk me through the propagation of AP from start to finish within the heart

SA node-AV node-bundle of his along septum down to apex and up ventricle sides

Anatomy

100

What is the structure supports electrical insulation?

cardiac skeleton

200

Name the layers of the heart

Endocardium Myocardium Epicardium Pericardium:

300

Explain what is coronary dominance

Right Dominant:In most hearts (around 80-85%), the right coronary artery (RCA) is the dominant vessel, meaning it gives rise to the PDA.

Left Dominant:In a smaller percentage of cases (around 10-15%), the left circumflex artery (LCx) or less commonly the left anterior descending artery (LAD) is the dominant vessel, and they supply the PDA.

Codominant:In a few instances (about 5-10%), both the RCA and the LCx/LAD contribute to supplying the PDA, making the heart codominant.

400

What does the bulbous cordis give rise to?

Right Ventricle:The bulbus cordis primarily forms the smooth-walled outflow tract of the right ventricle, also known as the infundibulum or conus arteriosus. It also contributes to the trabeculated part of the right ventricle. 

Ascending Aorta and Pulmonary Trunk:Together with the truncus arteriosus, the bulbus cordis forms the ascending aorta and the pulmonary trunk,

500

The left and right ventricles have pillar like muscles- what are they called, what are they made off, how many are there and where are they located?

Papillary muscles.

Right- Three: anterior, posterior, and septal papillary muscles

Left- Two: anterolateral, posteromedial

Cardiovascular conditions

100

What arteries are  at risk to cause MI or acute heart events

The coronary arteries, specifically the left anterior descending (LAD) artery, right coronary artery (RCA), and left circumflex (LCx) artery

200

5 factors that increases your risks of CVD

BMI

waist circumference

Smoking 

Exercise 

obesity 

diabetes 

family history 

past history 

300

How does atherosclerosis contribute to cardiovascular diseases such as myocardial infarction?

The plaque, primarily composed of fats and cholesterol, narrows the arteries, reduces blood flow to the heart muscle, and can rupture or lead to blood clot formation, ultimately causing a heart attack

400

pathophysiology of TOF

VSD, right ventricular hypertrophy, overriding aorta, stenosis 

500

Pathogenesis of atherosclerosis

1. Chronic stress on the endothelium (e.g., due to arterial hypertension and turbulence)
2. Endothelial cell dysfunction, which leads to:
   • Invasion of inflammatory cells (mainly monocytes and lymphocytes) through the disrupted endothelial barrier
   • Adhesion of platelets to the damaged vessel wall → platelet release of inflammatory mediators (e.g., cytokines) and platelet-derived growth factor (PDGF)
   • PDGF stimulates the migration and proliferation of smooth muscle cells (SMCs) in the tunica intima and mediates the differentiation of fibroblasts into myofibroblasts
3. Inflammation of the vessel wall
4. Macrophages and SMCs ingest cholesterol from oxidized LDL  and transform into foam cells (macrophages filled with lipid droplets). 
5. Foam cells accumulate to form fatty streaks (early atherosclerotic lesions).
6. Lipid-laden macrophages and SMCs produce extracellular matrix (e.g., collagen) deposition → development of a fibrous plaque (atheroma)  
7. Inflammatory cells in the atheroma (e.g., macrophages) secrete matrix metalloproteinases → weakening of the fibrous cap of the plaque due to the breakdown of extracellular matrix → minor stress ruptures the fibrous cap
8. Calcification of the intima 
9. Plaque rupture → exposure of thrombogenic material (e.g., collagen) → thrombus formation with vascular occlusion or spreading of thrombogenic materia

Random Cardio

100

What is the rate at which the SA node fires (bpm) and what overrides influences BPM.

Vagal nerve- slows it down

100

200

Explain what makes the lub-dub sound. Two parts explain the noise (what causes the noise-mechanism) and where does lub-dub occur?

Blood turbulence

The "lub" sound is the first heart sound, produced when the mitral and tricuspid valves close. The "dub" sound is the second heart sound, produced when the aortic and pulmonary valves close.

300

formula for mean arterial pressure?

MAP= CO x SVR

400

Three things that control venous pressure to the heart?

Muscle pump

respiratory pump 

blood volume 

pressure gradient 

500

What is the MOA, side effect of statins and an example of one?

1. HMG-CoA Reductase Inhibition:Statins are selective, competitive inhibitors of HMG-CoA reductase, the enzyme responsible for converting HMG-CoA to mevalonate, a crucial step in cholesterol synthesis.

2. Reduced Cholesterol Synthesis:By inhibiting this enzyme, statins lower the rate of cholesterol production within the liver.

3. Increased LDL Receptor Expression:The reduction in cholesterol within liver cells triggers an increase in the number of LDL receptors on the liver's surface.

4. Enhanced LDL Clearance:These increased LDL receptors allow the liver to more effectively remove LDL cholesterol from the blood circulation.

5. Overall Effect:The combination of reduced cholesterol synthesis and enhanced LDL clearance leads to a decrease in both cholesterol and triglyceride concentrations in the blood

simvastatin

rosuvastatin

Lucky Dip

100

Three clinical indications someone is having a cardio infarction

persistent, crushing chest pain or discomfort, pain or discomfort radiating to the arm, jaw, neck, or back, and shortness of breath or feeling lightheaded.

200

Three cells that can present antigens to T cells

dendritic

T cells

Macrophages 

300

5 branches of the brachial plexus

musculocutaneous nerve

ulnar nerve 

radial nerve 

median nerve 

axillary nerve

400

What are the three main nerves that innervate the hand and what areas do they innervate?

radial- thumb, index, half of middle

ulnar- half of middle, ring and little

median- the rest

500

Explain the steps involved in primary haemostasis

Vasoconstriction 

Platelet plug- adhesion, activation, aggregation