Cardiology Flashcards
What is the ideal blood pressure range?
90/60 - 120/80
At what blood pressure would you consider treatment for hypertension?
Clinical BP >160/100
OR >140/90 + signs of CVD or eng organ damage
What is the target BP for patients with hypertension?
<140/85
Unless diabetic with organ damage <130/80
Draw/describe the Renin Angiotensin System.
Macula Densa in kidneys detect drop in GFR via Na+ levels.
Juxtaglomerular Complex releases Renin.
Renin catalyses the conversion of Angiotensin (produced by liver) to Angiotensin I.
Angiotensin converting enzyme [ACE] converts Angiotensin I to Angiotensin II [vasoconstrictor].
Angiotensin II acts on andrenal gland causing release of aldosterone.
Aldosterone causes reabsorption of H20 via Na resorption.
Name two things that influence ADH (vasporessin release)
BARORECEPTORS:
Stretch receptors in arteries and large veins (particularly carotid sinus and aortic arch). Send signals to medulla when BP falls.
ANGIOTENSIN II:
Directly stimulates ADH release.
OSMORECEPTORS:
In hypothalamus detect when osmolality rises e.g. due to dehydration.
Where is ADH produced?
Hypothalamus
It is stored and released from the posterior pituitary.
Give two pieces of lifestyle advice for hypertension
Reduce stress Exercise Stop smoking Reduce salt intake Reduce weight Vegetarian diet
What is a homocystein test for?
Vitamin B12, B6 and Folate levels.
Homocystein is an amino acid found in high amounts in meat and it can cause damage to blood vessels increasing risk of CVD. B vitamins are required for its breakdown.
What is the 1st line antihypertensive treatment for a patient under 55yrs and white?
ACE inhibitor
What is the 1st line antihypertensive treatment for patients over 55yrs or Black?
Calcium Channel Blocker [CCB]
If not tolerated, then thiazide-like diuretic e.g. indapamide.
True or false, in diabetic patients, ACEi/ARB is the 1st line treatment for hypertension?
True
True or false, ACE inhibitors are safe during pregnancy?
False. ACEi such as Ramipril are teratogenic (particuarly in first trimester). Use Beta Blocker instead.
True or false, a contraindication for ACEi is renal failure?
True. ACEi are not nephrotoxic but they do reduce GFR.
Give two contraindications for beta blockers
Asthma
Complete Heart block
Bradycardia
What is heart failure?
When cardiac output is insufficient to meet the body’s needs
What is the difference between HFrEF and HFpEF?
HFrEF: Reduced ejection fraction [<40%]. The heart won’t contract appropriately [aka Systolic HF]
HFpEF: Preserved ejection fraction. Heart wont fill appropriately [aka Diastolic HF].
What is cor pulmonale?
Right sided heart failure
Blood can’t return to the heart effectively resulting in peripheral swelling.
What is the difference in symptoms between right and left heart failure?
Right (cor pulmonale): Primarily oedema as blood can’t return to the heart effectively.
Left: Dyspnoea, fatigue, chest pain as blood can’t return from the lungs.
What is the classification system used to assess heart failure? What are the 4 stages?
New York Classification
1) No limitation of physical activity
2) Slight limitation of physical activity. Unduly breathless with normal activities. Comfortable at rest.
3) Marked limitation. Breathless with less than ordinary activity. Comfortable at rest.
4) Symptoms present at rest.
What is the gold standard clinical test for heart failure?
Natriuretic Peptide Levels
[Also do CXR, ECG, Echocardiogram, FBC]
What is the treatment regimen for heart failure?
HFrEF: [LAB]
Loop diuretic
ACEi
Beta Blocker (carvedilol/bisoprolol)
HFpEF:
Loop diuretic
What is DASH?
Dietary Approaches to Stop Hypertension
[Low fat, low salt, medeterranean diet]
What kind of diuretic is best for pulmonary oedema? Which diuretic is best for peripheral oedema?
Loop diuretics e.g. furosemide, bumetanide.
[L for lungs]
Thiazide diuretics
e.g. Indapamide, Bendrofluazide.
[Remember azides affect NaCl channels and salt balance].
What channels do thiazide diuretics affect?
NaCl symporters in the DCT
[Contraindicated in gout, liver/renal failure]
What channels do loop diuretics affect?
NaK2Cl cotransporter in ascending loop
[Contraindicated in renal failure]
Name a potassium sparing diuretic
Spironolactone
Amiloride
How does the diuretic mannitol work?
Increases osmolarity in the proximal tubules
[Used for cerebral oedema and rhabdomyolysis]
True or false, Addison’s disease is a contraindication for potassium sparing diuretics
True.
Addisons [double down]
Cortisol and Aldosterone are low. Therefore, potassium is already higher than normal. Risk is hyperkalaemia.
Why do you tend to get pulmonary oedema with Left sided Heart Failure?
Blood is unable to return from the lungs to the left ventricle resulting in back pressure in the lungs.
Name two CXR signs of heart failure
Pulmonary oedema (Bat wing opacities)
Kerley B lines (horizontal lines in the lower aspect of the lungs)
Cardiomegaly (>50% thoraccic width)
Dilated upper lobe vessels
Pleural effusion
What is the Frank Starling law?
Stroke volume increases with end diastolic volume.
[Essentially, more blood in means more blood out].
What criteria are used for the diagnosis of Heart Failure?
Framingham Criteria
Major:
- Paroxysmal nocturnal dyspnoea/orthopnoea
- Neck vein distension
- Cardiomegaly
- Pulmonary oedema
- S3 gallop
- Rales (crackling lungs on inalation)
Minor:
- Ankle oedema
- Night cough
- Dyspnoea on exertion
- Hepatomegaly
- Tachycardia
- Pleural effusion
[2 major or 2 minor = Dx]
True or false, in heart failure you do not give NSAIDs.
True. Due to risk to kidneys.
How do you determine the cardiac axis from an ECG?
[‘Stand on one foot to find axis’ & if its Right its No -ve Problem +ve]
Normal
Lead I: +ve
aVF: +ve
Right
Lead I: -ve
aVF: +ve
Left
Lead I: +ve
aVF: -ve
What is the normal speed of an ECG?
25mm/second
How many seconds is one small square and one large square?
40ms (small)
200ms (large)
How many volts is one small square and one large square?
- 1mV (small)
0. 5mV (large)
How does the P wave differ in P Mitrale vs P Pulmonale?
P Mitrale (left atrial enlargement) = Biphasic P wave (just like ‘M’)
P Pulmonale (right atrial enlargement) = Enlarged P wave.
What is the normal axis of an ECG?
-30 to +90
How do you calculate the rate of an ECG?
300/number large squares between consecutive R spikes.
What is a normal PR interval?
120 - 200 ms
[3-5 small squares]
What are the three degrees of heart block? How do they present differently on ECG?
1st Degree:
- Fixed prolonged PR interval (>200ms)
- No lost QRS complexes
2nd Degree: Mobitz I (Wenckebach) - PR interval gets longer until QRS is dropped.
Mobitz II
- PR interval fixed but QRS drops intermittently.
3rd Degree:
- Complete dissociation between P waves and QRS complexes.
- Ps remain regular
- QRS remain regular
[In 3rd degree some Ps may get lost in QRS complexes]
If the PR interval is less than 120ms, there is a wide QRS and delta wave present, what does this suggest?
An accessory pathway e.g. Wolff Parkinson White syndrome.
[The accessory pathway in WPW is known as the Bundle of Kent]
What is the treatment for Wolff-Parkinson White syndrome?
If in AVRT:
- Vagal manoeuvers e.g. carotid sinus massage or ask patient to blow on 50 ml syringe
- Adenosine (not if AF!)
If symptomatic:
- Radiofrequency ablation
- Amiodarone
- Sotalol
NB: Don’t give digoxin. Increases risk of death!
What is the normal width of the QRS complex?
120ms
[3 small squares]
How do you tell if an ECG is in sinus rhythm? What possible diagnoses would you consider if not?
There should be clear P waves present. If not, then consider Atrial Flutter or Atrial Fibrillation.
How do you tell if a Q wave is present? What does it indicate?
If the Q is >25% the amplitude of the R then its a Q wave. This indicates an MI.
[Q waves appear around 1-12 hours into an MI]
What is the difference between ST elevation and ST depression?
ST elevation indicates full thickness MI i.e. infarction.
ST depression indicates myocardial ischaemia.
What is represented by the T wave?
Repolarisation of the ventricles.
In which leads is it normal to find T wave inversion?
V1 and Lead III
[
What are the ECG findings with Right and Left Bundle Branch Block?
RBBB: [MaRRoW]
V1: M
V6: W
LBBB: [WiLLiaM]
V1: W
V6: M
What is the difference between a pacemaker and an ICD?
Pacemakers deliver regular pulses to maintain a healthy cardiac rhythm e.g. in sick sinus syndrome, AF or heart block.
Implantable Cardioverter Defibrillator (ICD) only shocks the heart in the event of a cardiac arrest.
True or false, hair dryers are a risk for pacemakers?
True.
Any device that produces an EM field can interfere with pacemakers e.g. microwaves, induction hobs, and hairdryers.
Patients are advised to keep at least 2 ft away from such devices.
What are the ECG findings with Hyper and Hypokalaemia?
Hyperkalaemia:
- Tall tented T waves
- Wide QRS
Hypokalaemia: [PR STUF]
- PR int prolonged
- ST depression
- U waves
- Flat/bifid T wave
What is the treatment for Hyperkalaemia?
IV Calcium gluconate [cardio protective]
Soluble insulin + 50ml glucose
Salbutamol
Calcium resonium [K excretion]
What are the 4 categories of anti-arrhythmic drug according to the Vaughan Williams Classification? What is the mechanism of each?
- Na block
Mild: Procainamide
Moderate: Lidocaine
Strong: Flecainide - B1 Adrenergic block
e. g. Propanolol [B = 2nd letter] - K channel block e.g. Amiodarone
- Calcium Channel Block e.g. Diltiazem, Verapamil
Give two side effects of amiodarone
Pulmonary fibrosis
Thyroid issues
Slate grey skin
What are the three main categories of calcium channel blocker?
Dihydropyridines
[smooth muscle] lower peripheral resistance e.g. amlodipine, felodipine, nifedipine.
Benzothiazepines
[cardiac + smooth]
e.g. Diltiazem
Phenylalkylamines
[Cardiac] e.g. verapamil.
[From out to in DBP]