Flashcards in CVD Deck (117):
What is the diagnostic for MI?
Increased plasma Troponin
Other than MI, what other factors may cause Troponin levels to be elevated?
- Pulmonary embolism
- Chronic infection
NB: Troponin test is sensitive not specific!
What is the Fractional Flow Reserve?
A measure of the pressure drop after a narrowing in a vessel. Sometimes used in an angiogram to check flow sufficiency.
What is pre-test probability used for?
To assess a patient's risk to establish which tests can be performed.
Give 2 examples each of primary and secondary prevention of Acute Coronary Syndrome (ACS).
- Stop smoking
- Reduce cholesterol
- Exercise frequently
- PCI (stent)
Give 5 risk factors for CVD
- High cholesterol
- Type A personality
- Low exercise
What is angina?
Chest pain relating to ischaemia of the heart.
[Angina means 'choking']
What is the difference between stable and unstable angina?
Stable = Arterial stenosis. Predictable cause e.g. exercise or stress.
Unstable = Plaque rupture. Unpredictable. Can happen at rest.
How do you differentiate MI and angina?
Angina may last only a few minutes and will often relieve itself when patient rests/GTN spray.
MI typically lasts for 30mins+ and doesn't relieve with rest/GTN spray.
Pain character/radiation is the same for both.
What is Prinzmetal's angina?
Angina due to coronary artery spasm.
How much must coronary arteries stenose before symptoms appear?
Reduce by 75%.
What factors can precipitate angina?
What are the differential diagnoses for angina?
What are the treatments for MI and how do they work?
Beta-blockers (atenolol): Reduce HR --> increased coronary filling on diastole.
Nitrates (GTN): Dilate veins and reduce pre-load.
Calcium Channel Blockers (-pines): Dilate arteries and reduce afterload.
Antiplatelets (Aspirin/clopidogrel): decrease inflammation and reduce platelet aggregation.
What is the mechanism of action of clopidogrel?
Antiplatelet drug. Inhbits P2Y12 ADP platelet receptor.
In what % of people does clopidogrel not work?
25%. It is a pro-drug which requires metabolism to work.
Prasugrel is a new alternative which does not have this problem.
What is PCI?
Percutaneous Coronary Intervention
It is the insertion of a stent.
Comes with the risk of secondary thrombosis.
What do statins do?
What is CABG?
Coronary Artery Bypass Graft
Done in roughly 10% of heart attack cases.
- Internal thoraccic (mammary) artery is diverted.
- Great saphenous vein is harvested,
What are Q waves on an ECG a sign of?
Q waves occur when significant amounts of myocardium has undergone infarction.
Pronounced Q wave and small/no R wave is the classic presentation.
This is a sign of severe MI.
What is Levine's sign?
Patients with ACS will make a tight fist over their chest when describing the pain.
How do you distinguish anterior, posterior and inferior STEMI?
Anterior - ST/Jpoint elevation in anterior chest leads (V2/3).
Inferior - ST elevation in aVf, II and III.
Posterior - ST elevation in posterior leads V4-6) and depression in anterior leads.
What is Tako Tsubu cardiomyopathy?
Non-ischaemic, stress induced MI i.e. heart-break (broken heart syndrome), grief etc.
Catecholamines trigger a sudden weakening of the heart contraction.
Do you use anti-platelets or anticoagulants in pulmonary embolism?
Anticoagulants as it is a thrombus ("red clot" - fibrin rich). Example heparin.
What type of respiratory failure does pulmonary embolism cause?
CO2 is still able to leave but there is poor perfusion and therefore low O2.
How do you diagnose Pulmonary Embolism?
CTPA (CT with pulmonary angiogram).
In DVT what is more dangerous a proximal or distal clot?
Proximal as it is larger and prevents blood flow to a larger area.
What are the symptoms of DVT?
How do you diagnose DVT?
- Compression Ultrasound
- D-Dimer Test
NB: D-Dimer will be raised in patients with other trauma e.g. pregnancy, surgery or infection.
What is the treatment of DVT?
Heparin for 5 days.
Oral Warfarin for 6 months.
Compression stockings (surgical patients).
What can cause provoked thrombosis?
Pregnancy, long haul flights, long periods of bed rest.
NB: Spontaneous thrombosis is far more serious.
Does oestrogen increase or decrease the risk of DVT?
Combined contraceptive and HRT are risk factors.
What is the prevention venous thrombosis?
What is the difference between a red clot and a white clot?
Red = fibrin rich. Centralised thrombosis i.e. pulmonary embolism, DVT. Anticoagulant therapy.
White = platelet rich. Smaller vessels e.g. cerebral, coronary, and peripheral. Antiplatelet therapy.
What are some genetic causes of VT?
- Factor 5 Leiden (5% of pop).
- PT20210A (3% of pop).
- Anti-thrombin deficiency
- Protein c deficiency
- Protein S deficiency
What is an acquired cause of VT?
Folate/Vit B6 can reduce this
What is DOAC?
Direct Oral Anticoagulants e.g. rivaroxaban
Which clotting factors do DOACs act on?
Factor 2 and 10.
Which anticoagulant should you use in a pregnant mother?
Heparin as it does not cross the placenta.
DOACs and Warfarin do cross, don't use them!!
What is INR?
International Normalised Ratio.
Standardised measure of prothrombin (extrinsic clotting pathway).
Why are DOACs easier to administer vs. warfarin?
DOACs have a shorter half-life and therefore make achieving a required dose easier.
Is there a high dose regime for DOACs?
No. Use warfarin for this.
How does Heparin work?
Binds to anti-thrombin to potentiate its action, thus reducing clotting.
Before surgery, why must you stop aspirin at least 5 days in advance?
Aspirin disables platelets for the life-span of the platelet i.e. 5-7 days. Time is required for new platelets to be synthesised prior to surgery to avoid the patient bleeding.
Why can you give both aspirin and clopidogrel to the same patient?
They act on different pathways. Aspirin inhbits COX-1 and Clopidogrel inhibits P2Y12 receptor.
How does warfarin work?
Antagonises Vit. K pathway.
Clotting factors 10, 9, 7, 2.
What do you administer to reduce the effect of warfarin and how long does it take to work?
Takes 6-24 hours as new clotting factors need to be synthesised.
Why is dosing of warfarin difficult?
Warfarin has a long half-life (36hr lag). Dosage can therefore accumulate if rushed!
What are Chamberlain's 10 rules for a normal ECG?
1) PR interval 120-200ms (3-5 little squares).
2) QRS width <110ms.
3) QRS upwards in I and II.
4) QRS & T waves go in same direction.
5) aVr all waves are negative
6) R wave grows from V1 to V4.
7) ST segment is isoelectric (not elevated or depressed).
8) P waves upwards in I, II and V2-6.
9) No Q wave or less than 0.04 seconds in I, II, V2-6.
10) T wave upwards in I, II, V2-6.
On an ECG what is one small box horizontally?
0.04 seconds (40ms)
On an ECG what is one large box horizontally?
0.2 seconds (200ms)
On an ECG what is one large box vertically?
What is the standard paper speed of an ECG?
What is normal PR interval?
0.12 - 0.20 seconds
What is normal QRS duration?
0.08 - 0.10 seconds
What is normal QT interval?
0.4 - 0.43
(From start of Q to end of T.)
What do you see on the ECG in Wolf-Parkinson White?
PR interval shorter than 0.12 seconds.
ST elevation in which leads indicate anterior infarction?
What is the ECG diagnostic for LBBB?
V1 - W shape
V6 - M shape
What is the ECG diagnostic for RBBB?
V1 - M shape
V6 - W shape
What is the ECG diagnostic for heart block?
PR interval longer than 0.2 seconds.
Start of P to start of QRS complex.
How do you differentiate first, second and third degree heart block?
1st - regular, multiple P before QRS.
2nd - Some QRS missing. Type 1 regular skipping. Type 2 irregular skipping.
3rd - Total dissociation between P and QRS.
How do you spot Ventricular Hypertrophy?
Large R waves.
R waves get taller from V1-6 in healthy patients. One may be bigger than normal if hypertrophy!
Right leads = RVH
Left leads = LVH
In which leads is T wave inversion not typically pathological?
V1 - 3.
3% of adults may have this and be fine.
Give three conditions hypertension may go on to cause?
What is the diagnostic of hypertension?
Confirmed by ambulatory blood pressure monitoring (ABPM).
What is the main driver of hypertension?
Increased peripheral resistance.
What are the treatments of hypertension?
Angiotensin Receptor Blockers (ARBs)
Calcium channel blockers (CCB)
Alpha receptor blockers
Give two side-effects of ACEi?
- Renal failure (GFR decreases)
- Cough (kinin production).
- Teratogenic in pregnancy
What % of patients on ACEi develop a cough?
Do ARBs produce a cough?
No. They can be used in patients who are intollerant to ACEi.
Note however, that ARBs arent always as effective as ACEis.
Give an example of an ARB.
What are some of the side effects of ARBs?
Allergic swelling (angio-oedema)
Who do you not give ARBs to?
Pregnant mothers or conceiving parents as can affect early development.
What receptor does ARB act on?
Angiotensin II acts on this receptor.
What are the three types of L-type calcium channel blocker?
1) Dihydropyridine - amlodipine - smooth muscle --> reduces peripheral resistance.
2) Phenylalkylamine - verapamil --> reduce rate/force of contraction.
3) Benzothiazepines - diltiazem - reduces contraction and peripheral resistance.
NB: Verapamil causes constipation.
What are two side effects of CCBs?
Give two examples of beta blockers.
Does the heart have beta 1 or 2 receptors?
Both. Mostly B1.
NB: Beta blocker selectivity is relative not absolute.
Name two selective beta 1 beta blockers.
Give two side-effects of beta blockers.
Where do thiazides act?
Where does furosemide act?
Loop of Henle
What is Spironolactone?
What are 2 side effects of diuretics?
Low salts (K,Na, C)
Uric acid (--> gout)
Glucose tolerance (diabetes)
What is doxazosin?
Define heart failure.
Cardiac output is inadequate for the body's requirements.
Give three clinical presentations of heart failure?
Poor exercise tolerance
How might you differentiate between right and left heart failure?
Right = peripheral oedema due to pulmonary congestion (blood cant return).
Left = Respiratory symptoms and cyanosis as lungs/body aren't perfused.
What are the two main types of heart failure?
HFREF - HF w/ reduced ejection fraction (<40%).
HFPEF - HF w/ preserved ejection fraction (~50%).
Give two conditions which can lead to heart failure?
MI (most common).
Coronary Artery Disease
What is the diagnostic of heart failure?
- Elevated natriuretic peptides.
- Abnormal ECG.
What is the treatment for heart failure?
- Loop diuretics (Furosemide)
- ACEi (or ARBs if intolerant)
- Beta Blockers (titrate!)
- Aldosterone antagonist
- Nitrates (dilate veins)
What does digoxin do?
Activates vagal stimulation of the heart which reduces heart rate and force.
Na/K pump inhibitor.
Used in Heart failure and arrhythmia.
What is a side-effect of GTN?
What is the treatment for chronic stable angina?
- Antiplatelet therapy (aspirin/clopidogrel if intol.)
- Beta blocker
What are Vaughan Williams' 4 classifications for anti arrhythmic drugs?
1) Sodium channel blockers
2) Beta blockers
3) Prolong action potential
4) Calcium Channel Blockers
'Silly bloody pharmacology classification'
Give two side effects of digoxin.
Who must you avoid giving aniodarone and sotalol to?
Patients with Long QT syndrome as these drugs prolong QT and can kill them!
Give three side-effects of amiodarone (anti-arrhythmic)
- QT prolongation
- Interstitial pneumonitis
- Liver dysfunction
- Thyroid dysfunction
- UV sensitivity
- Slate grey complexion
- Corneal deposits
- Optic nerve neuropathy
- Warfarin interaction
How common is Hypertrophic cardiomyopathy (HCM)?
1 in 500
Are gene mutations causing cardiomyopathies usually recessive or dominant?
What kind of mutations usually give rise to dilated cardiomyopathies?
What kind of mutation results in arrhythmogenic cardiomyopathies?
Desmosome gene mutations.
Which chamber of the heart do arrhythmogenic cardiomyopathies manifest most frequently?
Right ventricle (fatty/fibro infiltration).
What are Brugada, CPVT, Long QT and short QT examples of?
Arrhythmogenic cardiomyopathies - ACM (ion channelopathies).
What drug is used to elicit Brugada ECG response?
What is the ECG pattern for Brugada?
ST elevation with descending slope on ST and negative T wave.
Is Naxos syndrome dominant or recessive?
Palmar Keratoderma + Wooly hair.
How much fluid normally fills the pericardial space?
What is cardiac tamponade?
A block on flow, usually caused by pericardial effusion.
Give three causes of pericarditis?
- Viral (enteroviruses, echovirus, coxsackievirus etc).
- Autoimmune - R.arthritis, scleroderma.
- Neoplastic (metastatic tumour).
- Metabolic (hypothyroidism).
What is the typical presentation of pericarditis?
Relieved leaning forwards
History of viral infection
How do you distinguish MI ECG from pericarditis?
1) PR segment depression only in Pericarditis
2) T inversion only in MI
3) Inf lead ST depression only in MI.
What is the management of pericarditis?
Usually resolves itself.
- Colchicine (gout med)
- NSAID (ibuprofen)
Give 2 structural heart conditions which would preclude pregnancy due to risk to the mother.
- Pulmonary hypertension
- Severe left heart obstruction
- Systemic ventricular impairment
- Marfans w/ aortic root >47mm