all Flashcards
What is aortic dissection?
A rare but serious cause of chest pain.
What is the pathophysiology of aortic dissection?
Tear in the tunica intima of the wall of the aorta.
What is the most important risk factor for aortic dissection?
Hypertension.
Name two syndromes associated with aortic dissection.
- Marfan’s syndrome
- Ehlers-Danlos syndrome
What are some associations with aortic dissection?
- Trauma
- Bicuspid aortic valve
- Collagens (Marfan’s syndrome, Ehlers-Danlos syndrome)
- Turner’s syndrome
- Noonan’s syndrome
- Pregnancy
- Syphilis
What is the typical nature of pain associated with aortic dissection?
Typically severe and ‘sharp’, ‘tearing’ in nature.
Where is the pain typically maximal in aortic dissection?
At onset.
In type A dissection, where is chest pain more common?
Chest pain is more common.
In type B dissection, where is back pain more common?
Upper back pain is more common.
What are some common features of aortic dissection?
- Pulse deficit
- Weak or absent carotid, brachial, or femoral pulse
- Variation (>20 mmHg) in systolic blood pressure between the arms
- Aortic regurgitation
- Hypertension
What can result from the involvement of specific arteries in aortic dissection?
- Coronary arteries → angina
- Spinal arteries → paraplegia
- Distal aorta → limb ischaemia
What ECG changes are typically seen in patients with aortic dissection?
Majority have no or non-specific changes; ST-segment elevation may be seen in a minority.
What are the two types in the Stanford classification of aortic dissection?
- Type A - ascending aorta, 2/3 of cases
- Type B - descending aorta, distal to left subclavian origin, 1/3 of cases
Describe the DeBakey classification type I.
Originates in ascending aorta, propagates to at least the aortic arch and possibly beyond it distally.
Describe the DeBakey classification type II.
Originates in and is confined to the ascending aorta.
Describe the DeBakey classification type III.
Originates in descending aorta, rarely extends proximally but will extend distally.
What is the correct answer for a significant increase in blood pressure after 20 weeks of gestation without proteinuria?
gestational hypertension
This condition is diagnosed when there is new-onset hypertension during pregnancy without any proteinuria or features of pre-eclampsia.
What blood pressure reading indicates gestational hypertension?
≥140/90 mmHg
This threshold is used to diagnose gestational hypertension according to UK guidelines.
What is required for a diagnosis of gestational hypertension?
new-onset hypertension without proteinuria or features of pre-eclampsia
Gestational hypertension is specifically characterized by the absence of proteinuria.
When is gestational hypertension diagnosed during pregnancy?
after 20 weeks of gestation
Diagnosis occurs if hypertension develops after this point in pregnancy.
What does COPD stand for?
Chronic Obstructive Pulmonary Disease
Which biomarker can be falsely elevated in patients with COPD?
B-type natriuretic peptide (BNP)
Where is BNP primarily released from?
Ventricular myocytes
What triggers BNP release from ventricular myocytes?
Increased wall tension and volume overload
What complications can develop in COPD patients leading to increased BNP production?
Pulmonary hypertension and right ventricular strain
What other factors related to COPD can stimulate BNP release?
Hypoxia and inflammatory state
True or False: Elevated BNP levels in COPD patients always indicate heart failure.
False
When interpreting BNP results in COPD patients, what should clinicians consider?
Values may be elevated due to the underlying respiratory condition
What is the first-line investigation for all patients according to the updated NICE guidelines issued in 2018?
N-terminal pro-B-type natriuretic peptide (NT-proBNP) blood test
This test is now required regardless of previous myocardial infarction history.
What should be arranged if NT-proBNP levels are ‘high’?
Specialist assessment (including transthoracic echocardiography) within 2 weeks
High levels are defined as > 2000 pg/ml.
What should be arranged if NT-proBNP levels are ‘raised’?
Specialist assessment (including transthoracic echocardiography) within 6 weeks
Raised levels are defined as 400-2000 pg/ml.
What hormone is produced mainly by the left ventricular myocardium in response to strain?
B-type natriuretic peptide (BNP)
Very high levels of BNP are associated with a poor prognosis.
What are the high level thresholds for BNP and NT-proBNP?
- BNP: > 400 pg/ml (116 pmol/litre)
- NT-proBNP: > 2000 pg/ml (236 pmol/litre)
These thresholds indicate high levels of the respective peptides.
What are the raised level thresholds for BNP and NT-proBNP?
- BNP: 100-400 pg/ml (29-116 pmol/litre)
- NT-proBNP: 400-2000 pg/ml (47-236 pmol/litre)
These thresholds indicate raised levels of the respective peptides.
What are the normal level thresholds for BNP and NT-proBNP?
- BNP: < 100 pg/ml (29 pmol/litre)
- NT-proBNP: < 400 pg/ml (47 pmol/litre)
These thresholds indicate normal levels of the respective peptides.
List factors that can increase BNP levels.
- Left ventricular hypertrophy
- Ischaemia
- Tachycardia
- Right ventricular overload
- Hypoxaemia (including pulmonary embolism)
- GFR < 60 ml/min
- Sepsis
- COPD
- Diabetes
- Age > 70
- Liver cirrhosis
These factors can cause elevated BNP levels.
List factors that can decrease BNP levels.
- Obesity
- Diuretics
- ACE inhibitors
- Beta-blockers
- Angiotensin 2 receptor blockers
- Aldosterone antagonists
These factors can cause reduced BNP levels.
What are the two classes of drugs used in diabetic nephropathy?
Angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARBs)
Examples include ramipril for ACE inhibitors and candesartan for ARBs.
What is the primary purpose of using ACE inhibitors and ARBs in diabetic nephropathy?
To reduce proteinuria and its progression
These drug classes have been shown to slow the progression of diabetic nephropathy.
What effect do ACE inhibitors and ARBs have on the afferent and efferent arterioles?
They dilate both afferent and efferent arterioles, but have a greater dilatory effect on efferent arterioles
This reduces intraglomerular pressure.
Why do ACE inhibitors and ARBs reduce intraglomerular pressure?
Angiotensin II normally has a stronger vasoconstrictive effect on the efferent arteriole
By dilating the efferent arteriole, these drugs decrease mechanical stress on the glomeruli.
What is the consequence of reduced intraglomerular pressure?
Decreased mechanical stress on the glomeruli and reduced protein leakage into the urine
This helps in preventing further glomerular damage.
Who should be offered an ACE inhibitor or ARB in the context of diabetic nephropathy?
All diabetic patients with hypertension and diabetic nephropathy and an ACR of 3 mg/mmol or more
ACR stands for albumin-to-creatinine ratio.
Fill in the blank: ACE inhibitors like _______ are used to treat diabetic nephropathy.
ramipril
Fill in the blank: ARBs like _______ are commonly prescribed for diabetic nephropathy.
candesartan
True or False: ACE inhibitors and ARBs can prevent further glomerular damage in diabetic nephropathy.
True
What are the two scenarios where cardioversion may be used in atrial fibrillation?
- Electrical cardioversion as an emergency for haemodynamically unstable patients
- Electrical or pharmacological cardioversion as an elective procedure for rhythm control
What is the purpose of synchronizing electrical cardioversion to the R wave?
To prevent delivery of a shock during the vulnerable period of cardiac repolarisation when ventricular fibrillation can be induced
According to the 2014 NICE guidelines, what should be offered if the onset of atrial fibrillation is less than 48 hours?
Rate or rhythm control
What should be started if atrial fibrillation onset is more than 48 hours or is uncertain?
Rate control
What anticoagulation treatment should be given if atrial fibrillation onset is less than 48 hours?
Patients should be heparinised and those with stroke risk factors should be put on lifelong oral anticoagulation
What are the options for cardioversion if atrial fibrillation is confirmed to be less than 48 hours?
- Electrical - ‘DC cardioversion’
- Pharmacological - amiodarone if structural heart disease, flecainide or amiodarone if no structural heart disease
Is further anticoagulation necessary after electrical cardioversion if AF is confirmed as less than 48 hours duration?
No, further anticoagulation is unnecessary
What should be done if the patient has been in atrial fibrillation for more than 48 hours?
Anticoagulation should be given for at least 3 weeks prior to cardioversion
What alternative strategy can be performed to exclude a left atrial appendage thrombus before cardioversion?
Transoesophageal echo (TOE)
What does NICE recommend for cardioversion in patients with AF for more than 48 hours?
Electrical cardioversion rather than pharmacological
What should be done if there is a high risk of cardioversion failure?
At least 4 weeks of amiodarone or sotalol prior to electrical cardioversion
For how long should patients be anticoagulated following electrical cardioversion?
At least 4 weeks
What should be considered after 4 weeks of anticoagulation following electrical cardioversion?
Decisions about anticoagulation should be taken on an individual basis depending on the risk of recurrence
What type of medication is Warfarin?
Oral anticoagulant
Used for managing venous thromboembolism and reducing stroke risk in patients with atrial fibrillation.
What has largely superseded Warfarin in treatment?
Direct oral anticoagulants (DOACs)
DOACs do not require the same level of monitoring as Warfarin.
What is the mechanism of action of Warfarin?
Inhibits epoxide reductase preventing the reduction of vitamin K
This vitamin K is essential for the carboxylation of clotting factors II, VII, IX, and X.
Which clotting factors are affected by Warfarin?
- Factor II
- Factor VII
- Factor IX
- Factor X
Mnemonic for remembering these factors is 1972.
What are the indications for Warfarin use?
- Mechanical heart valves
- Venous thromboembolism
- Atrial fibrillation
Target INR varies based on condition and valve type.
What is the target INR for venous thromboembolism when using Warfarin?
2.5, if recurrent 3.5
INR stands for International Normalised Ratio.
What is the target INR for atrial fibrillation when using Warfarin?
2.5
A consistent INR is crucial for effective treatment.
How are patients monitored while on Warfarin?
Using the INR (international normalised ratio)
This ratio compares the patient’s prothrombin time to the normal prothrombin time.
What is a characteristic of Warfarin’s half-life?
Long half-life
Achieving a stable INR may take several days.
What factors may potentiate the effects of Warfarin?
- Liver disease
- P450 enzyme inhibitors (e.g., amiodarone, ciprofloxacin)
- Cranberry juice
- NSAIDs (displace warfarin from plasma albumin and inhibit platelet function)
These factors can increase the risk of bleeding.
What are some common side effects of Warfarin?
- Haemorrhage
- Teratogenic effects
- Skin necrosis
- Purple toes
Skin necrosis can occur due to a temporary procoagulant state after starting Warfarin.
What happens to protein C biosynthesis when starting Warfarin?
Reduced
This can lead to a temporary procoagulant state, normally managed with concurrent heparin administration.
True or False: Warfarin can be used in breastfeeding mothers.
True
Warfarin is teratogenic but can be administered during breastfeeding.
What is pulsus paradoxus?
Greater than the normal (10 mmHg) fall in systolic blood pressure during inspiration, leading to faint or absent pulse in inspiration.
Associated with severe asthma and cardiac tamponade.
What condition is characterized by a slow-rising or plateau pulse?
Aortic stenosis.
This pulse pattern indicates a gradual rise and fall in arterial pressure.
What is a collapsing pulse associated with?
Aortic regurgitation, patent ductus arteriosus, hyperkinetic states (anemia, thyrotoxicosis, fever, exercise/pregnancy).
A collapsing pulse indicates a rapid rise and fall in arterial pressure.
What does pulsus alternans indicate?
Regular alternation of the force of the arterial pulse.
Commonly associated with severe left ventricular failure.
What is a bisferiens pulse?
‘Double pulse’ - two systolic peaks.
Seen in mixed aortic valve disease.
What is a ‘jerky’ pulse indicative of?
Hypertrophic obstructive cardiomyopathy (HOCM).
HOCM may occasionally be associated with a bisferiens pulse.
What does a normal apex beat indicate in aortic stenosis?
It indicates that the apex beat is not normally displaced.
What does displacement of the apex beat in aortic stenosis suggest?
It suggests left ventricular dilatation and hence severe disease.
What is Syndrome X?
A condition characterized by angina-like chest pain on exertion, ST depression on exercise stress test, but normal coronary arteries on angiography.
What are the features of Syndrome X?
- Angina-like chest pain on exertion
- ST depression on exercise stress test
- Normal coronary arteries on angiography
What management options are available for Syndrome X?
Nitrates may be beneficial.
True or False: Syndrome X is associated with abnormal coronary arteries.
False
Fill in the blank: Syndrome X features _______ on exercise stress test.
ST depression
What are the clinical features of symptomatic aortic stenosis?
- chest pain
- dyspnoea
- syncope / presyncope (e.g. exertional dizziness)
- murmur
- ejection systolic murmur (ESM) radiating to the carotids
- decreased following the Valsalva manoeuvre
The ejection systolic murmur is a key diagnostic feature of aortic stenosis, with its characteristic radiation and changes during maneuvers.
What are the features of severe aortic stenosis?
- narrow pulse pressure
- slow rising pulse
- delayed ESM
- soft/absent S2
- S4
- thrill
- duration of murmur
- left ventricular hypertrophy or failure
These features indicate the severity of aortic stenosis and help in clinical assessment.
What is the most common cause of aortic stenosis in older patients?
degenerative calcification
This is typically seen in patients over 65 years of age.
What is the most common cause of aortic stenosis in younger patients?
bicuspid aortic valve
This condition is prevalent in patients under 65 years.
Name a genetic syndrome associated with supravalvular aortic stenosis.
William’s syndrome
This syndrome is a rare cause of aortic stenosis related to genetic factors.
What management approach is typically taken for asymptomatic aortic stenosis?
observe the patient
Observation is the general rule unless other clinical indicators suggest intervention.
What is the management for symptomatic aortic stenosis?
valve replacement
Symptomatic patients typically require surgical intervention to replace the affected valve.
When should surgery be considered for asymptomatic patients with aortic stenosis?
if valvular gradient > 40 mmHg and features like left ventricular systolic dysfunction
These criteria indicate a higher risk of adverse outcomes, warranting surgical intervention.
What are the options for aortic valve replacement (AVR)?
- surgical AVR
- transcatheter AVR (TAVR)
- balloon valvuloplasty
Each option is chosen based on the patient’s age, operative risk, and specific clinical circumstances.
What is the treatment of choice for young, low/medium operative risk patients with aortic stenosis?
surgical AVR
This approach is preferred due to lower risks and better outcomes in suitable candidates.
What is transcatheter AVR (TAVR) used for?
patients with high operative risk
TAVR is a less invasive option for patients who may not tolerate traditional surgery well.
In what situation is balloon valvuloplasty used in adults?
limited to patients with critical aortic stenosis who are not fit for valve replacement
This procedure is less common and typically reserved for high-risk individuals.
What is a common characteristic of the ejection systolic murmur (ESM) in aortic stenosis?
classically radiates to the carotids
This radiation is a significant clinical finding during auscultation.
What changes occur to the ejection systolic murmur during the Valsalva manoeuvre?
decreased
The Valsalva manoeuvre affects the hemodynamics, altering the sound of the murmur.
