Passmed Cardiology Flashcards
Which part of the heart has the slowest rate of conduction?
AV node conduction
Atrial conduction
Ventricular conduction -> fastest due to purkinje fibres
What is the feature of the S4 heart sound?
Caused by atria contracting forcefully to overcome a stiff ventricle. It coincides with the P wave and is in late diastole.
Which pathologies are the S4 heart sound heard?
Aortic stenosis
Hypertension
Hypertrophic cardiomyoapthy
What are the features of S3 heart sound?
Caused by rapid diastolic filling of the ventricle, which occurs early in diastole.
What pathologies are related to the S3 heart sound?
Left ventricular failure such as dilated cardiomyoapthy
Mitral regurgitation
Constrictive pericarditis
Which artery commonly supplies the SA and AV node
Right coronary artery
Where do the coronary arteries drain?
Via the coronary sinus into the right atrium
Which pathology of the heart worsens afterload?
Ventricular dilatation, as there are less myocytes which are weaker and require more force to eject the same amount of blood.
How does mitral valve stenosis affect preload?
Reduces left ventiruclar filling that reduces preload.
What is the most important aspect of the CHADS-VASCULAR score?
Age
Prior stroke, TIA or thromboembolism
What are the components of the CAHDS2-score?
CHADS-2 VaSc score:
Congestive heart failure
Hypertension
Age over 75 years -> high weight
Age 65-74
Diabetes
Stroke TIA or thromboembolism -> high weight
Vascular disease
Sex female
What are the features of the ORBIT score?
Low haemoglobin
Age over 74
Bleeding history
Renal impairment with GFR below 60
Treatment with antiplatelet agents
What is a low risk ORBIT score?
0-2
What is a medium risk ORBIT score?
3
What is a high risk ORBIT score?
4-7
Why is aspirin not reccomended for stroke risk?
It can prevent clot-related stroke, however it increases the risk of haemorrhagic stroke.
What causes rapid depolarisaiton in cardiac action potential?
Sodium influx
How is left ventiruclar ejection fraction calculated?
Stroke volume/ EDV x 100
How is stroke volume calculated?
EDV of left ventricle - ESV of Left ventricle
How is systemic vascular resistance calculated?
Mean arterial pressure/ cardiac output
What is a complication of ventiruclar septal defect?
Aortic regurgitation, as the high velocity flow of blood through the ventricular septal defect can cause damage to aortic valve cusps, leading to relapse and subsequent regurgitation.
What is the action of nicorandil?
Potassium channel activated by activating guanylyl cyclase to decrease the sensitivity of smooth muscle to calcium and produce vasodilation.
It is given for primary pulmonary hypertension.
When should nicorandil be avoided?
Left ventircular fialure
What does pulmonary congestion, Orthopnea and reduced ejection fraction indicate?
Left sided heart failure
Which medication for hypertension can cause sexual dysfunction?
Indapamide, a thiazide like diuretic which can cause hypercalcaemia and hypokalemia and reduced glucose inotlerance.
It increases the risk of gout
Which drug for hypertension can cause hypertension?
Indapamide, a thiazide like diuretic which can cause hypercalcaemia and hypokalemia and reduced glucose intolerance
What is Type A aortic dissection?
Classically associated with chest pain, involving the ascending aorta
What is type B aortic dissection?
Classically has back pain, involves the descending aorta
What is dipyridamole?
A non-specific phosphodiesterase inhibitor which can lead to reduced uptake of adenosine
What is endothelin?
Potent vasoconstrictor and bronchoconstrictor secreted by endothelial cells that contributes to pulmonary hypertension, cardiac failure and Raynayd’ss.
It has no effect on systemic vascular resistance.
What promotes the release of endothelin?
Angiotensin II, ADH, hypoxia
What inhibits the release of endothelin?
Nitric oxide and prostacyclin
What are patients with heart failure at increased risk of?
Chest infection and ulcerated cellulitis legs
-> pulmonary congestion and oedema put patient at risk
-> peripheral oedema in lower limbs reduce skin integrity and loca circulation
Which pathogens increase risk of infection in patients with heart failure?
Streptococcus pneumoniae and haemophilius influenzae
Which pathogens are at increased risk of cellulitis?
Staphylococcus aureus and beta-haemolytic streptococci
What is endocarditis assoicated with?
Valvular heart disease
What is the first line therapy for heart failure?
ACE inhibitor and beta-blocker
-> consider ARB if intolerant
What is the alternative to ACEi and ARB for patients that are intolerant for first line treatment in heart failure?
Hyadrasalazine, a vasodilator which relaxes arteriole smooth muscle.
What is the second line therapy for heart failure with REDUCED ejection fraction?
Combination medication: Salcubitril and valsartan
Sacubitril is an angiotensin recpetor neprilysin inhibitor to increase the availability of ANP and BNP
It is ideal for those with reduced left ventricular fraction
What medication should be added for reduced ejection fraction heart failure with low heart rate below 75?
Ivabradine, a HCN channel blocker that is a rate-lowering drug to improve oxygen supply and reduce myocardial oxygen therapy.
Which medication is reccomended to be added be added as second line for those of African/Carribean descent?
Hydrasalazine and nitrate
What is hypertrophic cardiomyopathy?
Autosomal dominant disorder of muscle tissue where there is asymmetric septal hypertrophy and decreased compliance, causing anterior leaflet movement of the mitral valve.
Causes ventricular fibrillation in young people and syncope following exercise, but is often asymptomatic.
How to increase the sound of aortic murmurs?
Squatting
Expiration
Radiating legs
Adminstering nitrate
What is the MOA of adenosine?
Agonist of A1 except or which inhibits adenylyl cyclase to reduce cAMP levels and hyperpolarisation
What is the pathophysiology of atrial fibrillation?
Aberrant electrical activity between the left atrium and pulmonary veins, associated with eccentric hypertrophy of the cardiac muscle, interfering with signals from the SAN to the AVN
What causes risk of air embolus from the vessels?
Negative atria pressure
What causes a wedge shaped pacification on CXR?
Pulmonary embolism
What is an important consideration when using ticragrelor
P2Y12 receptor antagonist which inhibits ADP binding to platelet receptors and prevents the clearance of adenosine, causing increased levels in the circulation.
Adenosine stimulates ensory nerve fibres that produces dyspnoea.
What cardiac pathology cases increased pulse pressure?
Aortic regurgitation
What causes pulsatile hepatomegaly?
Tricuspid regurgitation
When does the S3 heart sound occur?
Rapid filing of ventricle:
With mitral regurgaition, dilated cardiomyopathy and constricted pericarditis
What organism is associated with infective endocarditis with poor hygeine?
Streptococcus viridans, commonly found in the mouth and associated with poor dental hygiene.
What causes S4 heart sound?
Stiff ventricle
-> aortic stenosis, hypertension and HOCM
What organism is the most common cause of infective endocarditis following prosthetic valve surgery?
Staphylococcus epidermis is
Which drug interferes with the action of antihypertensives?
NSAIDs
What causes a falsely low blood pressure reading?
Undersized blood pressure cuff,- not enough to fully encircle the arm
Elevation of arm above heart level- gravity reduces blood flow into arm
What would cause elevated blood pressure?
Undersized blood pressure cuff
Small elevations can occur if the patient talks during the reading
What is the most common cause of infective endocarditis?
Staphylococcus aureus
What organism is the most common commo cause of infective endocarditis in colorectal cancer?
Streptococcus bovis
Which antibiotic can cause Torsades de pointes?
Macrolide antibiotic
Which drugs can induce Torsades de pointes?
Antipsychotics
Tricyclic antidrepressants
Antihistamine terfenadine
Macrolide antibiotic
Chloqouinoilone
What is the action of dabigatran?
Direct thrombin inhibitor
What is the actio of rivaroxaban?
Inhibits factor X inhibitor
What is acute pericarditis?
Acute pericarditis is less than 4-6 weeks, and occurs due t viral infections, uraemia related to CKD, post myocardial infarction, malignancy, radiotherapy, connective tissue disease like lupus and trauma. There may be elevated troponin
Which valves close during QRS complex?
AV valves
Which groups may not experinece chest pain with ACS?
Diabetics and elderly
-> Treatment is MONA, with morphine, oxygen, nitrates and aspirin but oxygen only for sats less than 94%
How should heart failure in respiratory failure be managed?
Continuous positive airway pressure
What are the hostlogical findings 0-24 hours post MI?
early coagulative necrosis, neutrophils, wavy fibres, hypercontraction of myofibrils. High risk of ventricular arrhythmia, HF and cardiogenic shock
What are the histological findings 1-3 days post MI?
Extensive coagulative necrosis, neutrophils (associated with fibrinous pericarditis)
What are the features of atrial fibrillation?
Aberrant electrical activity between left atrium and pulmonary veins
What causes heart rate that varies on respiration?
Sinus Arrythmia due to exhalation causing increase in vagal tone temporarily that results in bradycardia.
How does AVN block present on clinical examination?
Regular pulse and bradycardia
What are the complications of atrial fibrillation?
Cardiac tamponade
Stroke
Pulmonary vein stensois
What are the complications of atrial fibrillaiton?
Cardiac tamponade
Stroke
Pulmonary vein stenosis
What are the features of abdominal aortic aneurysm?
They are located below renal arteries and smoking and hypertension is a major risk factor. Aneurysms less than 5.4 cm should be monitored with regular ultrasound surveillance.
Rare risk factors of abdominal aortic aneurysm is connective tissue disorders like Ehlers Danlos.
What is a common complication of abdominal aortic aneurysm repair?
Aortoduodenal fistula is a common complication of abdominal aortic aneurysm repair
What are U waves?
Small positive deflections after the T wave, best seen in leads V2 and V3, and is one of the best reliable indicators of hypokalemia after 2.7 mmol.K
What can cause QT prolonging?
Hypokalemia
What can cause short QT interval?
Hypercalcaemia
How does hypokalemia affect the QRS complex?
ST depression and T wave flattening
How can mitral stenosis affect other systems?
Obstruction of left atrium enlargement can compress the oesophagus and cause dysphagia and compress recurrent laryngeal nerve and lead to stridor.
Right ventricular failure can cause hepatic venous congestion and ascites.
What does a widened mediastinum indicate?
Thoracic aortic rupture
What are the features of abdominal aortic aneurysm is aneurysm?
Failure of elastic proteins in extracellular matrix causes dilation of all 3 layers of arterial wal, typically caused by degeneerative disease. It occurs below renal arteries and risk factors are smoking and hypertension
What is the criteria for abdominal aortic aneurysm?
3cm or greater is considered aneurysmal
What is the criteria for intervention in abdominal aortic aneurysm?
Diameter reaching 5.5cm in men
What is the criteria for surveillance in abdominal aortic aneurysm?
Over 3cm should be mentored with regular ultrasound.
Between 4.5 to 5.4cm, scanning shud occur every 3 months
What is the most common location of traumatic aortic rupture?
Proximal descending aorta distal to origin of left subclavian artery
What does tearing chest pain and aortic regurgitation indicate
Aortic dissection due to a tear in the tunica intima, that creams a false lumen which fills with blood.
What causes diastolic dysfunction of the heart with a high septal thickness?
Hypertrophic obstructive cardiomyopathy which is associated with sudden cardiac death, syncope and heart failure. It results in reduced ejection fraction
How do the coronary arteries change during atherosclerosis?
Reduced nitric oxide bioavailability
Pro-inflammatory
Pro-oxidant
How does pulmonary embolism affect the ECG?
T wave inversion in anterior leads
Sinus tachycardia
Signs of right heart strain
What is the cause of varicose veins?
Incompetency of superficial varicose veins
What causes increased levels of BNP levels?
Hypoxaemia
Diabetes
Sepsis
Liver cirrhosis
What causes decreased BNP levels?
Obesity
Diuretics
ACE inhibtiors
Beta blockers
What is dresseler syndrome?
Autoimmune mediated pericarditis occurring 2-6 weeks after myocardial infarction. It presents with fever and pleuritic pain, with diffuse ST elevation and PR depression
How does necrosis of the hypertensive arteriopathy affect?
Fibrinoid necrosis, due to deposition of fibrin in the vessel wall, giving a pink appearance on haemotoxylin staining.
This is associated with malignant hypertension.
Which organisms is associated with infective endocarditis in patients with prosthetic valves?
Staphylococcus epidermis is
Which organisms is the most commonly associated with infective endocarditis?
Streptococci viridans
Which complication is most likely to occur 5-14 days after an MI?
Cardiac tamponade
Which complication is most likely to occur 3 days after an MI?
Ventricualr septal defect
Which complication is most likely to occur weeks aftern an MI?
Mural thrombus
Dressler syndrome
How does an arterial ulcer present?
Occur on the toes and heel
Typically have a ‘deep, punched-out’ appearance, Painful and there may be areas of gangrene
Typically Cold with no palpable pulses and Low ABPI measurements
How does hypocalcaemia affect QT interval
Prolongs
How does hypercalcaemia affect the QT interval?
Shortens
What is an aschoff bodies?
Granulomatous nodules found in rheumatic heart fever
What electrolyte abrmalites cause long QT?
Hypokalemia
Hypocalcaemia
Hypomagnesaemia
What causes a falsely elevated BP?
Undersized blood pressure cuff
Talking during reading
What causes a falsely low BP?
Elevation of arm above heart
Measured arm supported during reading
What is the oxygen saturation in right atrium?7
70% as it is the deoxygenated blood form thebdoy
What is the most important aspect of the CHADS-VASC2 score?
Age
What are the features of mitral stenosis?
Mitral stenosis causes Malar flush, loud S1 with opening snap and irregularly irregular heart rhythm and left atrial enlargement. Most common cause is rheumatic fever. There may be haemoptysis due to hig pulmonary pressure and atrial fibrillaiton
What are the histological findings 2 weeks to several months post MI?
contracted scar complete. Associated with Dressler syndrome, HF, arrhythmias, mural thrombus
