John Palmer's Chest Pain Flashcards
What must FXa be bound to to contribute to coagulation?
FVa
What are the symptoms of heart failure mostly attributable to?
Decreased venous drainage
What did the CAST trial show?
Class I anti arrhythmics will not improve survival when used prophylactically
What does increased preload do to cardiac contractility?
Increased contractility
What does 2 P waves per QRS on an ECG reflect?
2nd degree heart block e.g. 2:1 type, Mobitz 2
Why does exercise increase cardiac contractility?
Increased sympathetic stimulation
How can cardiovascular risk factors be described?
Synergistic
Which ligand binds to the P2Y12 receptor?
ADP
Which vector does aVR correspond to?
Right arm
At what speed does endocardium to epicardium conduct at?
0.3 m/s
What does the PR interval reflect the function of?
AV node
What pumps most of the calcium out of the cell in relaxation?
the NCX (Ca2+:3Na+) antiporter
Which vector does lead II correspond to?
Right arm to left leg
Which cell mediates plaque rupture in atherosclerotic plaque?
Macrophages
What do class III anti-arrhythmic drugs do?
Prolongs AP and refractory period
During isovolumetric relaxation which valves are open and which are shut?
All valves are shut
How does fondaparinux work?
Inhibits FXa via activation of antithrombin
Name a clot buster
Streptokinase
What is atrial fibrillation a risk factor for?
Thromboembolism
Why may people not adhere to post-MI treatment?
Anexity and depression
Which thrombi should be treated with anti-platlet drugs?
Arterial
What does prothrombinase consist of?
FXa and FVa
Give two class II anti-arrhythmic drugs.
Atenolol and B blockers
What is abciximab?
A GPIIb-IIIa inhibitor
What does the law tell us?
What we must do and not do
What does article 2 of the Human Right’s Act 1998 give everyone the right to?
Life
Give two class I anti-arrhythmic drugs.
Fast Na+ channel blockers and flecainamide
Where do eosinophils often migrate to?
The GI tract
What does ventricular tachycardia result in?
Fulminant heart failure
What is congestive heart failure?
When left heart failure leads to right heart failure
What is orthopenoea?
Pulmonary oedema on lying down
Why might someone who is having a heart attack be breathless?
Cardiac output is low
What percentage of artery must be occluded for it to be significant occlusion?
70%
How many people over 70 have heart failure?
10%
What do basophils contain?
Pro-inflammatory granules
At what speed does the AV node conduct at?
0.05 m/s
How much fluid flows through capillaries per day?
4000L
Which leads are the chest leads?
V1, V2, V3, V4, V5, V6
What direction is lead I in if left is 0 degrees and we are moving clockwise?
0 degrees
Which of ticagrelor and clopidogrel prevents cardiovascular events better?
Ticagrelor
What do type 2 atheromatous lesions contain?
Smooth muscle cells
Which way will increasing contractility move the cyclic graph of volume against pressure of the cardiac cycle?
Upwards because the pressure in the heart is increasing
What is a first line drug for heart failure treatment?
ACE inhibitor
How do B1 receptors increase contractility?
By increasing the slow inward current
How many wires and leads are there in a standard ECG?
10 wires and 12 leads
How do platlets bind to Von Willebrand factor?
Via GP1B
Which cardiac murmer can be caused by incompetence of the semi lunar valves?
Heard after the second heart sound
When is an inverted T wave normal?
In V1
Which ligand binds to the GPIIb/IIIa receptor?
Fibrinogen
What do inotropic agents do?
Increase contractility
What is the typical hydrostatic pressure gradient along a capillary?
25 mmHg, higher at arterial end
What is the magnitude of a voltage on an ECG a reflection of?
The vector of depolarisation in the direction of the lead
How do neutrophils produce energy?
Anaerobic glycolysis
What does a type 4 atheromatous lesion have?
A fibrous cap
What do anti-coagulants do?
Prevent growth of a thrombosis
What are If channels?
Funny current channels
What causes the depolarisation upstroke in the cardiac action potential?
Voltage gated sodium channels
Where do haemopoietic stem cells derive from originally?
Mesenchyme
What do class I anti-arrhythmic drugs do?
Terminate re-entry arrhythmias and slow conduction through conducting system
What is happening in ventricular filling?
AV valves are open and blood is forced into ventricle but cannot leave as the aortic and pulmonary valves are shut
What does warfarin do?
Inhibits Vit K dependent epoxide reductase activity,
which modifies FVII, FIX, FX, and prothrombin (FII) during synthesis in liver
How does anti-thrombin work as an anti-coagulant?
Inactivates factors IIa, IXa, XIa, XIIa when not in clot
Which factors are activated in amplification of coagulation?
V and VIII
What is the most common form of myocardial infarction?
Transmural
How many patients with newly identified heart failure survive at least 3 months?
75%
What does article 8 of the Human Right’s Act 1998 give everyone the right to?
Self determination
Which heart sound can indicate raised EDP?
S3-S4 gallop rhythm
What does increased mean arterial pressure cause?
Increased afterload
How many people in UK have heart failure?
650,000
What combo of drugs should be used in heart failure?
ACE i and B blocker
What do platelets release when activated?
ADP, TXA2, serotonin
Which way will increasing afterload move the cyclic graph of volume against pressure of the cardiac cycle?
To the right as there is high EDP therefore high filling
Which vector does aVF correspond to?
Left leg
What percentage of UK women over 75 have CHD?
25%
Which drug induces early after depolarisations?
Procainamide
How do platelets stick together?
By fibrinogen binding
When do neutrophils die?
After phagocytosing a single pathogen
How does GTN work?
Metabolised to NO which relaxes veins and venules to decrease CVP and LVEDP so therefore decreases CO and O2 demand by Starling’s law
What is the ejection fraction usually in systolic heart failure?
Less than 45%
What kind of nucleus does a basophil have?
Bilobed nucleus
Which is the rhythm lead?
Lead II
How does Warfarin work?
Antagonises vitamin K
Which ligand binds to the intergrin A2 B1 receptor?
Collagen
Which adrenergic receptors does carvedilol antagonise?
A1, B1, B2
What is the plane of detection for the leads of Einthoven’s triangle?
Oblique
According to Starling’s law what must be equal on the left and right sides of the heart?
Stroke volume
What is the shape of a platelet?
A biconvex disc
How do NO and prostaglandin work as anti-coagulants?
Inhibit platelet aggregation and activation
By how much does chronic stress increase risk of CHD?
100%
What coagulation factor is thrombin?
FII
What kind of nucleus does a erythrocyte have?
No nucelus
What is the PR interval?
The time from beginning of P wave to the beginning of the Q wave
What does no P waves on an ECG reflect?
Atrial fibrillation
What is the length of the QRS complex?
80 ms
Which are the anti-platelet drugs?
Aspirin, clopidogrel, ticagrelor, abciximab
Which ligand binds to the GP1B receptor?
vWF
What is happening in the ejection phases?
The aortic and pulmonary valves open and blood is ejected into aorta and pulmonary valve
What initiates amplification of coagulation?
Thrombin
What is the plane of detection for the chest leads?
Transverse
What kind of nucleus does a lymphocyte have?
Large circular nucleus that fills the cell
Which drug induces delayed after depolarisations?
Digitoxin
What direction is lead III in if left is 0 degrees and we are moving clockwise?
120 degrees
How fast do atria beat in atrial flutter?
300 bpm
During isovolumetric contraction which valves are open and which are shut?
All valves are shut
What are megokaryocytes precursors of?
Platelets
What type of cell is a neutrophil?
Granulocyte
What does cholesterol in atheromatous plaques form?
Crystals
During atrial systole which valves are open and which are shut?
The atrio-ventricular valves are open and the aortic and pulmonary valves are shut
What is the daily net movement of fluid from microvasculature to interstitium?
8L
What regulates capillary pressure gradients?
Changes in arteriole resistance
Which ligand binds to the GPV1 receptor?
Collagen
How do chronotropic agents increase heart rate?
Increasing If current
What are the most common risk factors for heart failure?
MI and HT
Which cells release tissue plasminogen activator?
Damaged endothelial cells
Is cardiac muscle more or less sensitive to stretch than skeletal muscle?
More sensitive to stretch
At what heart rate will a ventricular cell take over as cardiac pacemaker?
30 bpm
Do B blockers improve symptoms or mortality in heart failure?
Both
What direction is lead II in if left is 0 degrees and we are moving clockwise?
60 degrees
What will be lower than normal in a failing heart?
Stroke volume
What percentages of WBCs are lymphocytes?
40-70%
Which are the anti-coagulation drugs?
Heparin, warfarin
What does chronic stress cause the release of?
Catecholamines
What is a normal haemocrit?
40%
In initiation of coagulation what does tissue factor bind to?
FVII
Where would a thrombus which is mainly a product of coagulation be found?
In a vein
Which channels bring SA nodes to threshold?
If channels only
What can’t cardiac muscle produce regarding action potentials?
A summation of action potentials
How do the action potentials of the epicardium and endocardium compare?
It is shorter in the epicardium
What percentages of patients only show partial response to clopidogrel?
33%
Which leads are bipolar?
I, II, III
What is happening in isovolumetric contraction?
Ventricles are in systole but valves are yet to open so no volume changes, preparing to push blood forcefully out into aorta and pulmonary artery
What does tenase consist of?
FVIIIa and FIXa
What do cardiac glycosides cause?
Decreased removal of Ca2+ from the cell
What direction is aVL in if left is 0 degrees and we are moving clockwise?
-30 degrees (+300)
What type of cell is a NK cells?
Lympocyte
What is the infarct caused by diffuse stenosis without thrombus or embolism known as?
Subendocardial
How does tissue factor pathway inhibitor work as an anti-coagulant?
Combines with and inactivates FXa
What direction is aVR in if left is 0 degrees and we are moving clockwise?
-180 degrees (+210)
How does ivabradine decrease the work of the heart?
Inhibits If (current of pacemaker potential in SAN) to decrease O2 demand and increase supply
What do P2Y12 antagonists prevent?
Platelet aggregation
What proportion of the UK population has CHD?
4%
What does PR intervals that progressively increases until a QRS complex is missed on an ECG reflect?
Wenckebach-type 2nd degree heart block
What causes the plateau phase of the cardiac action potential?
The open state of L-type calcium channels
What do verapamil and amlodipine do?
Block Ca2+ entry into smooth and cardiac muscle so decrease force, relax arterial vessels so decrease TPR and O2 demand
What is an issue with GTN?
Tolerance builds up due to formation of reactive oxygen species inhibiting ALDH-2
How long do neutrophils survive in the circulation?
5 days
What does PR upstroke, delta wave, on an ECG reflect?
Accessory pathway from atria to ventricles
Which pathogen are eosinophils important in destroying?
Parasites
How does rivaroxaban work?
Directly inhibits FXa
What does nicorandil do?
K+ channel agonist, opens K+ channels in vascular smooth muscle cells to cause cell hyperpolarisation, vasodilation so decrease TPR and decrease O2 demand
What happens to ventricles during heart failure?
Ventricles dilate
During rapid and reduced ejection phase which valves are open and which are shut?
AV valves are shut and the aortic and pulmonary open to allow blood to be pushed out
What should the ejection fraction of a healthy person be?
55-75%
How does heart failure cause oedema?
Venous pressure is increased
What type of cell is a monocyte?
Agranulocyte/ mononuclear cell
Which leads are augmented and unipolar?
aVL, aVR, aVF
What metabolises glyceryl trinitrate (GTN)?
ALDH-2
What do eosinophil granules contain?
Basic, cytotoxic proteins
By how much will a cardiac rehabilitation programme reduce CHD mortality?
25%
How does heart failure ultimately cause death?
Cardiac arrhythmia
Name an irreversible P2Y12 antagonist.
Clopidogrel
What is happening in isovolumetric relaxation?
Full diastole of the heart, atria fill with blood slowly to prepare for next cardiac cycle
What does heparin inhibit?
Factors XIIa, XIa, Xa, IXa and IIa (thrombin)
What is the extracellular matrix of blood made of?
Plasma
What does streptokinase activate?
Plasminogen
Where does the bundle of Kent run in WPW?
Right ventricle to right atrium
What is the length of the QT interval?
300-450 ms
What do class IV anti-arrhythmic drugs do?
Slows conduction in AV node, slows ectopic pacemakers and reduces AV node excitability
In stenotic valvular disease what causes heart failure?
Increased afterload
What type of cell is a T cell?
Lympocyte
How much air in the blood stream would kill someone?
300 ml
How does unfractioned heparin work?
Inhibits FXa and thrombin via activation of antithrombin
What differentiates reticulocytes from mature erthrocyte in regards to staining?
RNA stains differently
How does aspirin work?
Irreversibility binds COX and inhibits platelet aggregation
What is the hydrostatic pressure in the interstitum?
0 mmHg
What is the length of the PR interval?
120-200 ms
What is the diameter of a lymphocyte?
6-9 micro metres
What do statins inhibit?
HMG-CoA reductase
According to Starling’s law what does the energy released in contraction depend on?
The cardiac fibre length
When do latent pacemakers increase in automaticity?
In ischaemia
Which act informs the treatment of people ages 16 and over that lack capacity to consent for treatment?
The Mental Capacity Act 2005
Which anti-arrhythmic drugs slows heart rate in atrial fibrillation without affecting contractility?
Digitoxin
How does dabigatran work?
Directly inhibits thrombin
What percentage of heart failure is systolic?
70%
What are delayed rectifier channels?
K+ channels
What causes heart failure after myocardial infarction?
Ventricular dilation
Which vector does lead III correspond to?
Left arm to left leg
What determines cardiac output?
Central venous pressure
What is the preferred immediate treatment for myocardial thrombus?
Cardiac cathertisation
How do B blockers help angina symptoms?
By blocking sympathetic stimulation of heart to decrease force and HR so decrease O2 demand, increase coronary blood supply so increase O2 supply
What kind of nucleus does a monocyte have?
Horseshoe shaped nucleus
Name an ARB (angiotension receptor blocker)
Valsartan
What activates prothrombin?
FXa
How does digitoxin increase intracellular Ca2+ in myocytes?
Increases intracellular Na+
Where are erythroid precursor cells found?
Bone marrow
What kind of nucleus does a megakaryocyte have?
Multi nucleated
At what speed do Purkinje fibres conduct at?
4 m/s
What direction is aVF in if left is 0 degrees and we are moving clockwise?
90 degrees
Which heart sound would indicate delayed conduction?
Split S1 as that is conduction from atria to ventricles
What is a normoblast the precursor of?
Erthrocyte
What forms the blood brain barrier?
Capillary endothelium
What is pitting oedema a sign of?
Elevated venous pressure
Which fibrillation results in sudden death?
Ventricular fibrillation
Where does haemopoiesis take place in the early embryo?
Liver
Give two class IV anti-arrhythmic drugs.
Diltiazem and slow-inward L-type Ca+ channel blockers
Which vector does lead I correspond to?
Right arm to left arm
What does no correspondence between P waves and QRS complexes on an ECG reflect?
Complete heart block
Do loop diuretics improve symptoms or mortality in heart failure?
Symptoms
Name a direct FXa inhibitor
Rivaroxaban
How is GTN administered?
Patches
What does erythropoietin promote?
Growth and division of normoblasts
How long after an infarct does ventricular rupture usually occur?
10 days
What do platelet dense granules contain?
Serotonin
What do class II anti-arrhythmic drugs do?
Inhibits effect of adrenaline
When are fibrinolytics used?
To lyse a clot
After reaching threshold which channels control the upstroke of the SA node action potential?
L-type calcium channels
Give two class III anti-arrhythmic drugs.
Amiodarone and delayed-rectifier K+ channel blockers
What is the main pharmacological strategy to deal with angina of effort?
Decrease blood O2 demand
Which vector does aVL correspond to?
Left arm
What kind of nucleus does a neutrophil have?
Multi lobed nucleus
What is the normal percentage of circulating red blood cells that are reticulocytes?
1%
What type of cell is a basophil?
Granulocyte
What is an arterial infarct without bacterial contamination called?
White, bland infarct
At what speed do the atria conduct at?
1 m/s
What is the diameter of a normal platlet?
3 micro metres
What is claudication?
Muscle pain on exercise
What is the current model of coagulation known as?
The cell-based model
During rapid and reduced ventricular filling which valves are open and which are shut?
AV open, pulmonary and aortic shut
What is preload determined by?
Central venous pressure
Which thrombi are platelet rich?
Pale thrombi
How is heparin activity tested?
Measure partial thromboplastin time
What does long PR interval on an ECG reflect?
1st degree heart block
What is the diameter of a normal erythrocyte?
7 micro metres
Which factor causes cross-linking of fibrin?
XIIIa
What does an M pattern for the QRS complex likely to indicate?
Bundle branch block
What initiates cardiac contraction in atrial fibrillation?
The AV node
Which of clopidogrel and aspirin reduces mortality more?
Clopidogrel
Which channels determinate heart rate?
Potassium channels and If channels
Where do newly produced blood cells first enter?
Through a sinusoid
How does heparin work as an anti-coagulant?
Activates anti-thrombin
Where do symptoms of weakness in heart failure come from?
Increased arterial vasoconstriction
Is splitting of the second heart sound always pathological?
No
What is the INR?
Prothrombin time
