Cardiovascular Flashcards
What is preload?
how full the ventricle is when it starts to contract
What is after load?
how much force is required to push the blood out of the heart
How is cardiac output calculated?
Heart rate x stroke volume
How is stroke volume calculated?
End diastolic volume – end systolic volume
How is ejection fraction calculated?
How is mean arterial pressure calculated?
Name the parasympathetic neurotransmitters and receptors
Acetylcholine
Muscarinic receptors
Name the sympathetic neurotransmitter and receptor
Adrenaline
Beta 1 receptors
What happens to blood vessels when alpha receptors are targed with antagonists (blockers)
Vasoconstriction
Where are the pacemaker cells of the heart located and what is their function
SA Node
Set the heart rate (depolarise and set off an action potential which is then carried throughout the heart)
Briefly explain the stages of the cardiac cycle
0- depolarisation, sodium influx
1- peak depolarisation, efflux of potassium and chloride
2- Platau phase, Calcium influx, potassium efflux
3- repolarisation, efflux of potassium
4- return to base potential maintained by influx and efflux of potassium
What should the paper speed be for an ECG?
25mm/s
How many seconds is one large square on an ECG?
0.2s
How many seconds is one small square on an ECG?
0.04s
What should a normal P-R interval be (in seconds and in squares!)
0.12-0.2 (3-5 small squares)
What should a normal QRS be (in seconds and in squares!)
<0.12s (<3 small squares)
What should a normal QT interval be (in seconds and in squares!)
<0.42s at 60BPM (<10.5 small squares)
How can the heart rate be calculated from an ECG?
count how many QRS complexes in 30 big boxes then x10 for BPM (30 big squares = 6 seconds!)
What does ARIBAR stand for?
Any electrical activity?
Rate?
Irregular or regular rhythm?
Broad QRS complexes?
Any P waves?
Relationship between P wave and QRS
What are the 4 classes of cardiac drugs?
Class I: membrane stabilising drugs (e.g. lidocaine, flecainide)
Class II: beta-blockers
Class III: amiodarone; sotalol (also Class II)
Class IV: calcium-channel blockers (includes verapamil but not dihydropyridines)
What type of drug are aspirin, tiagcrelor and clopidogrel?
Anti-platelet
What is the MOA of aspirin?
COX inhibitor
What is the MOA of ticagrelor and clopidogrel?
P2Y12 ADP receptor antagonist
Name some anticoagulant drugs
Prasugrel
Fondiparinux
Heparin
Warfarin
DOACs (-ban)
What is the MOA of prasugrel and fondiparinux?
P2Y12 inhibitors
What is the MOA of LMW heparin?
Activates antithrombin III. Forms a complex that inhibits factor Xa
What is the MOA of unfractioned/standard heparin?
Activates antithrombin III. Forms a complex that inhibits thrombin, factors Xa, IXa, Xia and XIIa
What is the MOA of warfarin?
Vit K antagonist
What is the roe of vitamin K in the coagulation cascade?
co-factor in the production of clotting factors II, VII, IX and X (1972)
What is the MOA of apixiban?
Direct Factor Xa inhibitor
What is the MOA of dabigatran?
Prevents activation of fibrinogen into fibrin
What conditions are B blockers contraindicated in?
asthma
peripheral vascular disease
raynauds
heart block
HF
Name some central and peripherally acting calcium channel blockers
Central - diltazem/ verapamil
Peripheral - Amlodipine/ felodipine
Describe how the effects of central and peripheral CCB’s are different
Central - rate limiting
Peripheral - lower BP by causing vasodilation
What is the function of ivabradine and how does it achieve this function?
Rate limitation - blocks potassium channels in the sinoatrial node
What is the MOA of statins?
inhibit 3H3MG CoA reductase in the liver which stops production of cholesterol
What is the MOA of ACE inhibitors?
Prevents ACE from cleaving angiotensin I into angiotensin II
What type of drug is spironolactone?
Aldosterone Antagonist (potassium sparing diuretics)
What is the MOA of nicorandil?
Potassium channel agonist
What is the MOA of furusomide?
inhibit the Na+/K+/2Cl- co-transporter
What kind of drugs are losartan & candesartan?
Angiotensin receptor blockers
How does adenosine work?
binds to adenosine (A1 & A2) receptors in the AV node which slows/ blocks conduction through the AV node
How does amiodarone work?
blocks potassium channels prolonging repolarisation of myocytes
(leadsto longer action potential)
What is INR?
a measure of how long blood takes to clot
What does an INR of 2 mean?
blood takes twice as long as normal to clot
What scoring system can be used to assess the risk of bleeding in patients on warfarin?
HASBLED
When should warfarin levels be assessed?
12 hours after last dose
What should your INR be if you are NOT on warfarin?
<1.1
What is the therapeutic range for warfarin?
2-3
What is the target INR if you have had a VTE?
2.5
What should the target INR be if you have had multiple VTE?
3.5
What is the target INR in AF?
2.5
What is the target INR if you have a mechanical heart valve?
2.5-3.5
What should doctors do if INR is between 5-8 and the patient is not bleeding?
withhold 1-2 doses
reduce subsequent maintenance dose
What should doctors do if INR is 5-8 and the patient is bleeding?
Stop warfarin
give vit K 1-3mg IV
restart vit K when INR <5
What should doctors do if INR >8 and the patient is not bleeding?
stop warfarin
vit K 1-5mg oral
repeat dose of vit K if INR is still too high within 24 hours
restart warfarin when INR<5
What should doctors do if INR >8 and the patient is having minor bleeding?
Stop warfarin
1-3mg vit K IV
repeat dose of vit K if INR is still too high within 24 hours
What should doctors do if the warfaranised patient is having major bleeding?
stop warfarin
5mg vit K IV
Prothrombin complex or FFP
which valves are in the Left side of the heart?
Mitral valve -> Aortic valve
which valves are in the right side of the heart?
Tricuspid -> pulmonary
How many leaflets do each of the heart valves have?
All heart valves have 3x leaflets except mitral (2x)
Describe the murmur of mitral stenosis
Mid to late diastolic, loud S1 & split S2, rumbling, low pulse volume
Describe the murmur of aortic regurgitation
Early diastolic, high pitched, blowing
Describe the murmur of mitral regurgitation
Holosystolic, Soft S1 & split S2, high pitched, blowing
Describe the murmur of aortic stenosis
Ejection systolic, soft S2 & S4, slow rising
Which pathology would give a collapsing pulse
PDA
Aortic regur
Which pathologies give an ejection systolic murmur
Tetrology of fallot
HOCM
pulmonary stenosis
Aortic stenosis
Which pathology gives a loud S2
Pulmonary hypertension
What is heard in L ventricular failure?
S3
What is heard in a L->R shunt?
Loud S1
What pathology gives a continuous murmur?
Septal defects
What is rheumatic heart disease?
a result of body’s overreaction to a group A beta-haemolytic streptococcal infection.
What histological finding is indicative of rheumatic heart disease?
Aschoff bodies
What valvular pathology does rheumatic heart disease cause?
Mitral stenosis (the only cause of this is rheumatic heart disease!)
Describe first degree heart block
Prolonged PR interval
How is first degree heart block managed?
No treatment required
Describe Second degree heart block, Mobitz I (Wenckebach)
PR intervals progressively elongate until a QRS is dropped
How is second degree heart block, Mobitz I (Wenckebach) managed?
No treatment required
Describe Second degree heart block, Mobitz II
PR intervals are consistent but some complexes are dropped
How is Second degree heart block, Mobitz II managed?
Pacemaker if symptomatic
Describe third degree heart block
No correlation between P and QRS
How is third degree heart block managed?
Pacemaker
How is VF managed?
Shock
CPR
Adrenaline 1mg & Amiodarone 300mg
How is pulseless VT managed?
Shock
CPR
Adrenaline 1mg & Amiodarone 300mg
How is pulsed VT managed?
Unstable
- synchronised cardioversion 1st line
- Amiodarone + synchronised cardioversion 2nd line
Stable
- Amiodarone 1st line
- Cardioversion 2nd line
How is Atrial flutter managed?
Direct-current (DC) cardioversion.
Antiarrhythmic drugs/nodal rate control agents.
Rapid atrial pacing to terminate atrial flutter.
Ablation of the abnormal circuit
How is SVT managed?
vagal manoeuvres/ carotid sinus massage and adenosine can be given to terminate an episode.
How is Wolf-parkinson-white identified on an ECG?
Delta wave (upstroke of QRS- nike tick!)
How is wolf Parkinson white managed?
Vagal manoeuvres
Adenosine to revert to sinus rhythm
How is torsades de pointes managed?
Vagal manoeuvres
IV magnesium sulphate, beta blocker, and atrial pacing
How is a LBBB identified on an ECG?
V1 WilliaM V6
How is RBBB identified on an ECG?
V1 MorroW V6
What scoring system should be used to assess whether a patient with atrial fibrillation should be anticoagulated or not
CHADSVASC
What would a CHADSVASC of 0, 1 and 2 mean for coagulation?
0= no treatment
1= anticoagulate males (not females scoring 1)
> 2 = anticoagulated
What are the 4H’s and 4T’s of cardiac arrest (reversible causes)
Hypoxia
Hypovolaemia
Hypo- / hyperkalaemia / metabolic
Hypothermia
Thrombosis - coronary or pulmonary
Tamponade - cardiac
Toxins
Tension pneumothorax
What type of STEMI occurs when there is a block in the right coronary artery? Give the corresponding ECG leads and the areas of the heart supplied by this artery
Inferior STEMI (Leads II, III and aVF)
This branch supplies right atrium & ventricle, Inferior aspect of left ventricle and posterior septal area
What type of STEMI occurs when there is a block in the Left Circumflex Artery? Give the corresponding ECG leads and the areas of the heart supplied by this artery
Lateral STEMI (Leads I, aVL, V5-6)
This branch supplies left atrium and posterior aspect of left ventricle
What type of STEMI occurs when there is a block in the Left anterior descending artery? Give the corresponding ECG leads and the areas of the heart supplied by this artery
Anterior STEMI (Leads V1-4)
This branch supplies anterior aspect of left ventricle and anterior aspect of septum
List the primary prevention methods for Acute coronary syndrome
Diet – total fat <30% calories
Exercise – 150 mins moderate intensity per week or 75 mins high intensity.
Statin- If QRISK >10%. Atorvastatin 20mg. Give regardless of QRISK if diabetic or CKD.
What is the acute treatment of stable angina?
GTN – Immediate relief
B Blocker/CCB – long term relief
What is the secondary prevention for stable angina?
A-ACE Inhibitor
A-Antiplatelet (aspirin/ Clopidogrel/ ticagrelor)
A-Atorvastatin 80mg
A-Atenolol
(2nd letters = CNTT)
What is the acute management of unstable angina?
Give MONA
Morphine, oxygen, nitrates, aspirin 300mg
Same day assessment
What is the acute treatment of STEMI?
Give MONA
Morphine, oxygen, nitrates, aspirin 300mg
Then..
PCI if within 12 hours of symptom onset and within 2 hours of presenting. Give Prasugrel.
OR
Thrombolysis if within 12 hours of symptoms but PCI not available within 2 hours
What is the acute treatment of NSTEMI?
B – basis for decision = GRACE
* Low risk ≤3% - give ticagrelor
* High risk ≥3% - PCI immediately if unstable or within 72 hours if stable. Give prasugrel or tiacagrelor,
A – Aspirin 300mg
T – Ticagrelor 180mg (clop if bleed risk, prasugrel if going for angio)
M - morphine
A – antithrombin (fondaparinux – don’t give if going for angio!)
N – Nitrate
What is the secondary prevention of unstable angina, STEMI and NSTEMI?
A-ACE Inhibitor
A-Antiplatelet (Clopidogrel/ ticagrelor) for 12 months
A-Atorvastatin 80mg
A-Atenolol
A-Aldosterone antagonist for those with heart failure
A-Aspirin 75mg indefinitely
CNTTAL
How can unstable angina be differentiated from NSTEMI?
NSTEMI- raised trops
Unstable angina - normal trops
What is meant by primary and secondary prevention?
Primary = before disease has occurred
Secondary = After disease has occurred
Which type of patients would benefit from a CABG?
> 70% stenosis of left main stem artery
significant proximal three-vessel coronary artery disease
two vessel coronary artery disease that includes significant stenosis of proximal left anterior descending coronary artery and who have an ejection fraction < 50%.
Name 4 Post MI complications that occur within 0-3 days of MI
Arrhythmia
Cardiogenic shock
Pericarditis
Stoke
What is a late complication of MI (>2 weeks after)
Left ventricular aneurism
How does the body sense blood pressure?
using sinuses in the aortic arch and carotid arteries (carotid baroreceptor)
What controls
A) Short term blood pressure
B) Long term blood pressure
???
The arterial baroreflex = short term control
kidneys via renin-angiotensin-aldosterone system = Long term control
List the stages of hypertension and the correlating clinic and ambulatory blood pressures
List the clinic and ambulatory blood pressure targets for patients <80 and patients >80
List the causes of secondary hypertension
R – Renal disease
O – Obesity
P – Pregnancy
E – Endocrine
D – Drugs (alcohol, NSAIDs)
How is hypertension managed?
ACE (-pril) – If <55 or diabetic
CCB (-pine) If >55 or African-carribean
Combination
Indapamide
ARB (e.g. candesartan)
How is resistant hypertension managed?
K+ > 4.5 = thiazide like diuretic
K+ < 4.5 =spironolactone
What is the definition of orthostatic hypertension?
blood pressure decrease of 20 mmHg systolic and/or a diastolic pressure of 10 mmHg within three minutes of standing.
How is heart failure diagnosed?
- Pro-BNP
- ECHO then MUGA scan for left ventricular dysfunction
How does Pro-BNP help guide urgency of investigation?
400-2000 = echo within 6 weeks
>2000 = echo within 2 weeks
Describe the stages of heart failure and the associated ventricular function
How is heart failure managed?
ABAL
A- ACE inhibitors
B- Beta blockers
A- Aldosterone receptor blockers
L- Loop diuretic
What is infective endocarditis?
Infection of the endocardium (innermost layer of the heart)
Which valve is most commonly affected in infective endocarditis?
Mitral
How does infective endocarditis look on an ECG?
Prolonged PR interval
What is the criteria used in infective endocarditis?
Modified dukes
What is the overall most common cause of infective endocarditis and the most common cause seen in IVDUs
S. Aureus
What is the most common cause of infective endocarditis in developing countries and in those with poor dental hygiene?
Strep viridian’s
What is the most common cause of infective endocarditis seen with indwelling lines or within 2 months of prosthetic valve surgery?
Strep epidermidis
What is the most common cause of infective endocarditis in those with colorectal cancer?
Strep Bovis
What is the most common non-infective cause of endocarditis?
SLE
what is the initial blind therapy for infective endocarditis?
Amoxicillin
What antibiotic should be given in endocarditis if the patient has staph and a natural valve
Fluclox
What antibiotic should be given in endocarditis if the patient has staph and a prosthetic valve?
fluclox, ripampicin + gent
What antibiotic should be given in endocarditis if the patient has strep?
Benzylpenicillin
What is the difference between a true aneurism and a false aneurism?
True = involves all 3 layers
False= involves 1 or 2 layers
Describe the Stanford classification of aneurisms
Describe the DeBakey classification of aneurysms
How does a forward aneurism tear present?
How does a backward aneurism tear present?
What findings can be seen on CT
- Mediastinal widening
- False lumen can be seen on CT
Describe the management of an aortic aneurism
Which classification system can be used to classify peripheral limb disease?
Fontaine Classification
Describe the stages of the Fontaine classification
What is the first line investigation in limb ischaemia?
duplex scan
Describe the difference between arterial and venous ulcers in terms of appearance, location and treatment
How long should a provoked DVT be treated for?
3 months
How long should an unprovoked DVT/ DVT in malignant picture be treated for?
6 months