CV&R Non-Anatomy Flashcards
What are 5 risk factors for atherosclerosis?
Age
Male
Family history
Smoking
Obesity
Hypertension
What are the 4 causes of chest pain ?
Cardiac
Respiratory
GI
Musculoskeletal
(+others)
What can cause cardiac chest pain ?
Ischaemia
Aortic dissection
Pulmonary embolism
Aortic stenosis
Pericarditis
Myocarditis
What are the two classifications of cardiac chest pain ?
Troponin positive
Troponin negative
What bare Troponin Positive cardiac conditions ?
Type 1 and 2 MI, SCAD, coronary spasm
What’s are Troponin Negative cardiac conditions ?
Angina (stable or unstable)
Cor spasm
Micro vascular/endothelial
What is the investigation pathways for cardiac conditions ?
Exercise tolerance test ( ETT) ——— stress echo, perfusion scan, CT coronary angiogram or stress perfusion cMR ———invasive coronary angiogram
What shows an ischaemia on an ECG ?
ST wave depression (during ETT)
What drug treatments can be used for angina ?
Beta blockers (-olol)
Calcium agonists (-dipine for smooth muscle + verapamil on the heart)
Nitrates (GTN spray)
What are the 3 acute coronary syndromes ?
Unstable angina - unstable plaque without myocardial necrosis
NSTEMI - thrombus without total vessel occlusion (ST depression)
STEMI - total vessel occlusion (ST elevation)
What are lipids ?
Water insoluble
3 classes = cholesterol, triglycerides, phospholipid
What is cholesterol a precursor to ?
Steroid hormones (oestrogen, testosterone, cortisol, aldosterone )
Endogenous vitamin D production
What is the structure of a lipoprotein ?
Central hydrophobic lipid core (triglycerides and cholesterol esters)
Surface layer of polar components (phospholipids + free cholesterol + apolipoproteins)
What is the LDL calculation ?
LDL = TOTAL CHOLESTEROL — HDL — TRIGLYCERIDES/5
Describe anticoagulant HEPARIN mechanism of action
Binds to and enhances antithrombin III, this bind to and inhibits clotting factors II,IX,XI and XII
Given intravenously or sub-cutaneously
Side effects = allergic reactions, haemorrhage, HIT, hyperkalaemia
Describe anticoagulant Warfarin mechanism of action
Structural Analogue of Vit K
Blocks vit. k reductase and therefore carboxylation
Blocks coagulation factor synthesis in the liver
Oral administration
Side effects = haemorrhage, crosses placenta and BBB (foetal haemorrhage)
Deceive aspirins use as an anti-thrombolytic agent
Used in low doses
It inhibits platelet synthesis, and COX irreversibly
Prevents re infarction (lowers risk by 20%)
Describe tissue plasminogen activator (t-PA) as a fibrinolytic ?
Enzyme produced by vascular endothelium
Only activate s plasminogen bound to fibrin (clot selective)
Side effects = haemorrhage
What are platelets derived from ?
Megokaryocytes in bone marrow
What normally suppresses platelet activation ?
Prostacyclin
Nitric oxide
Antithrombin III
What do fibrin strands enmesh ?
Erythrocytes and platelets
What is Von Willebrand disease ?
A deficiency in Von Willebrand factor (binds platelets to collagen)
What is Haemophilia A ?
Deficiency of factor VIII (8)
What is Haemophilia B ?
Deficiency of factor IX (9)
What is Haemophilia C ?
Deficiency of factor XI (11)
What digests fibrin I to soluble degradation products ?
Plasmin (activated by t-PA)
What is the treatment for venous thrombosis ?
Anticoagulants
What is the treatment for arterial thrombosis ?
Fibrinolytics (immediate)
Antithrombotics (long-term)
What is coronary steal ?
During vasodilation, When blood is diverted to already well perfumed areas
What do beta1-adrenoceptor blockers do ?
Competitive antagonists if adrenaline and noradrenaline at cardiac beta1-adrenoceptors
Decrease HR and SV, decrease myocardial O2 demand
What does Ivabradine do ?
Blocks Na current causing delay in SA node depolarisation
Decreases HR (not force), decreases myocardial O2 demand
What is after-load ?
Force against which LV contracts
What is pre-load?
Diastolic pressure that distends LV
What causes reduces after-load ?
Dilation of arteries
What causes reduced pre-load ?
Dilation of veins
What is the Bainbridge Reflex ?
Initiated by increased blood in atria
Causes stimulation of SA node
Stimulates barorecptors in the atria, causing increased SNS stimulation
What does P in the ECG wave show ?
Atrial depolarisation
What does P-Q show in ECG waves ?
Delay at AV node
What happens at Q of ECG wave ?
Conduction through bundle branches
What also happens at Q of ECG wave ?
Conduction through purkinje fibres
What happens at the QRS complex of ECG waves ?
Ventricular depolarisation
What happens at S-T of ECG waves ?
Plateau phase of re polarisation
What happens at T wave of ECG ?
Rapid Repolarisation
What causes a U wave to sometimes be present on an ECG ?
Repolarisation of Purkinje fibres
Which leads are unipolar ?
aVR
aVL
aVL
Chest leads 1-6
Which leads are bipolar ?
I = RA-LA
II= RA-LL
III= LA-LL
Which ECG leads are anterior ?
V1-V4
Which ECG leads are inferior ?
II , III, aVF
Which ECG leads are lateral ?
I, aVL, V5 + V6
What does a wave look like that is horizontal -ve to +ve from L to R ?
All positive wave
What does a wave look like that is horizontal -ve to +ve from R to L ?
All negative wave
What does an ECG wave look like that is -ve to +ve superiority to inferiorly ?
Positive and negative parts STANDARD PQRST ECG WAVE
How do you calculate HR from ECG ?
300/no. of big squares between each QRS
OR
No. of QRS complexes across ECG (10 seconds) x 6
What is normal angle for the QRS axis ?
-30 to +90 degrees (from limb lead I)
How do you find the QRS axis ?
By finding lead with most positive QRS complex
What shows left axis deviation ?
-30 to -90 degrees
Positive QRS in I
Negative in II and aVF