Cardiology Flashcards
What is the MOA of Sacubitril?
- Neprilysin inhibition
- Neprilysin is an enzyme that degrades atrial and brain natriuretic peptides (ANP, BNP), bradykinin and adrenomedullin which are endogenous vasodilating peptides.
- Sacubitril therefore increases the levels of these peptides.
- Antihypertensive effect:
1. reduce blood volume
2. increased sodium excretion
Sacubitril-valsartan improves outcomes in HFREF (heart failure with reduced ejection fraction) compared to Enalapril. What are these outcomes (3)?
- Reduced cardiac death and hospitalisation for HF
- Reduced overall mortality
- Reduced symptoms and improved function
Summary: improved morbidity, mortality and symptoms
Combining ACEi and Neprolysin inhibition (sacubutril) leads to what serious complication?
Serious angioedema - therefore sacubitril is combined with ARB.
T/F: continuous infusion of epoprostenol (Flolan) improves the survival of patient with pulmonary arterial hypertension.
True.
What is epoprostanol?
- drug version of Prostacyclin (aka Prostaglandin I2)
- potent vasodilator and inhibits platelet activation
Post ACS, addition of which drug to statin therapy improves cardiovascular outcomes?
Ezetimibe
T/F: Obesity is an independent risk factor for AF
True
What ECG signs are suggestive of dextrocardia?
- Tall R-wave in V1
2. Absent R-wave in V6
Patient has ECG findings suggestive of dextrocardia and reports being infertile, what is the diagnosis
Dextrocardia + Infertility = Kartagner’s syndrome
Infertility is due to ciliary dyskinesia
Transmission of which pathogen is peculiar to cardiac transplant from the donor heart compared to other solid organ transplants?
Toxoplasma gondii.
What % of patients with HFREF have central sleep apnoea?
15%
How is ‘severe’ aortic stenosis defined according to the following parameters:
- VA: Valve area (cm^2) - also, what is considered ‘critical’?
- PV: Maximum aortic velocity - aka peak velocity (m/s)
- MPG: Mean pressure gradient (mmHg)
- VA less than 1 (critical is less than 0.6) cm^2
- PV more than 4 m/s
- MPG more than 40 mmHg
In the medical treatment of HOCM, what drugs are recommended and which should be avoided?
Name 2 of each.
Recommended:
1st line - beta blockers
2nd line - verapamil (non-dihydropyridine CCB)
Avoid (may worsen LVOT obstruction):
- GTN (vasodilators)
- Frusemide (diuretics)
T/F: Most cardiac tumours are benign.
True (75% benign)
What is the most common type of cardiac tumour?
Where is it usually located?
- Myxomas (mesenchyme origin) that are capable for neural and endothelial differentiation.
- 80% found in the left atrium, the rest in the right atrium.
What is the clinical significance of a positive parasternal heave?
Suggests RV-hypertrophy, rarely left atrial enlargement pushing RV forward.
What are the 2 clinical pre-cordial findings of pulmonary HTN?
- Parasternal heave - RV-hypertrophy
2. Palpable P2 (i.e. P2 tap) - closure of PV
In the Stress ECG test, which of the following is more specific for myocardial ischaemia:
- Upsloping ST depression
- Horizontal ST depression
- Downsloping ST depression
Horizontal and downsloping is more specific
What specific ECG finding on a Stress ECG test is considered ‘positive’ for myocardial ischaemia?
Great than or equal to 1 mm horizontal/downsloping ST depression in one or more leads that persists at 80 milliseconds after the J point.
What are 6 ECG end-points on a Stress ECG test that should prompt termination of the test?
Ischaemia:
1. Marked ST depression
Arrhythmias:
- New BBB
- VT or VF
- Increasing ventricular ectopy
- SVT
- HB (Mobitz II or CHB)
What are 3 types of ventricular ectopy?
- Premature beats
- Couplets
- NSVT
What mechanism creates the ‘ultra’ sound in the ultrasound probe?
- Striking of piezo-electrical crystals with an electric pulse.
- Crystals release sound waves
With ultrasonography, what is the relationship of the frequency of the ultrasound and resolution and tissue penetration?
Increased frequency leads to INCREASED resolution but DECREASED tissue penetration.
For the E/A ratio of cardiac ultrasound (pulse-wave doppler across the MV), what is the significance of the E-wave and A-wave?
Is the ratio positive or negative under normal conditions?
E-wave (early wave) = passive filling of the ventricle
A-wave (atrial wave) = active filling with atrial systole
Normally, E-wave is slightly greater than A-wave, therefore E/A ratio is usually POSITIVE.
REVERSAL of the E/A ratio (i.e. negative value) in cardiac doppler is due to which process (give 4 potential causes)?
Decrease LV compliance.
4 examples: old age, HTN, LVH, diastolic dysfunction
EXAGGERATION of the E/A ration (i.e. more positive) in the cardiac doppler is due to which process (give 3 potential causes)?
Decrease in LV compliance.
3 examples: restrictive cardiomyopathy, contrictive pericarditis, infiltrative cardiac disease (e.g. amyloidosis)
What is the classic ECG finding with Digoxin toxicity?
Reverse tick sign - downsloping ST depression
Describe the mechanism behind the type of arrhythmia that Digoxin toxicity causes.
Increased automaticity (increased intracellular calcium) and decreased AV conduction (increased vagal effects at the AV node) leads to:
- SVT: due to increased automaticity
- Slow ventricular response: due to decreased AV conduction
i.e. ’atrial tachycardia with block’.
What is the MOA of Ezetimibe?
What are the 2 main AEs?
Lowers cholesterol by decreasing the absorption of cholesterol in the small intestines.
AEs: steatorrhoea and headache
Does high or low calcium levels cause prolongation of the QT interval and hence increase risk of torsade de pointes.
Hypocalcaemia causes prolonged QT
For each of the following options:
- Troponin
- Myoglobin
- CK-MB
Match to the most appropriate comments:
- first to rise post-MI
- returns to normal after 2-3 days
- remains elevated for 10d
- Troponin - remains elevated for 10d
- Myoglobin - first to rise post-MI
- CK-MB - returns to normal after 2-3 days
What is the most common cause of sudden cardiac death in the young patient?
HOCM
In a normotensive 13 week pregnant women with a previous history of pre-eclampsia. What medication will decrease the risk of recurrence?
low-dose aspirin
What is the most common cause of ‘cyanotic’ congenital heart disease at birth or in the first few days?
Transposition of the Great Arteries (TGA) is the most common cause in neonates.
What is the most common cause of ‘cyanotic’ congenital heart disease in general?
Tetralogy of Fallot (occurs 1-2 months after birth)
What is the most common cause of ‘acyanotic’ congenital heart disease?
Ventricular Septal Defect (VSD)
What is the anatomical abnormality in patent ductus arteriosus?
Connection between the pulmonary trunk and descending aorta
T/F: Patent ductus arteriosus is a CYANOTIC congenital heart defect.
False - acyanotic.
Describe the murmur of a patent ductus arteriosus in terms of the following:
- Character of murmur
- Location of murmur
- Associated pulse character
- Associated features (2)
- Character of murmur: continuous ‘machinery’ murmur
- Location of murmur: left sternal edge (subclavicular)
- Associated pulse character: collapsing pulse
- Associated features (2):
- Widened pulse pressure
- Heaving apex beat
For following phases (0-4) of the cardiac action potential, describe the flux of electrolytes.
0 - rapid depolarisation 1 - early repolarisation 2 - plateau 3 - final repolarisation 4 - restoration
0 - rapid depolarisation
- rapid INFLUX of sodium
1 - early repolarisation
- EFFLUX of potassium
2 - plateau
- EFFLUX of potassium in balance with slow INFLUX of calcium
3 - final repolarisation
- EFFLUX of potassium
4 - restoration
- Resting potential (-96mV) restored by Na+/K+ ATPase (Na+ out and K+ in)
- Na+ slowly enters until threshold potential reached triggering a new action potential
T/F: skeletal remains contracted longer than cardiac muscle.
False - cardiac muscle remains contracted 10-15x longer than skeletal muscles.
What is the conduction velocity (m/s) in the following regions of the heart:
- Atrium
- AV-node
- Ventricle
- Atrium = 1 m/s (slow)
- AV-node = 0.05 m/s (fastest)
- Ventricle = 2-4 m/s (fast)
Regarding congenital ‘coarctation of the aorta’:
- What is the anatomical abnormality and what sign does it yield?
- Which sex is it more common in?
- What is the anatomical abnormality?
- narrowing of the descending aorta leading to radio-femoral delay - Which sex is it more common in?
Male
Which 4 conditions is ‘coarctation of the aorta’ associated with?
2BaNT:
Berry aneurysm
Bicuspid AV
Neurofibromatosis
Turner’s syndrome
What are 6 poor prognostic factors in HOCM?
LL-FANS:
Low BP on exercise LV wall thickness greater than 30mm FHx of sudden death Age - young at presentaiton NSVT on holter monitor Syncope
Patient with AF has background of WPW. Which of the following medications can be given and which should be avoided?
- Digoxin
- Flecainide
- Metoprolol
- Verapamil
- Adenosine
Inhibiting the AVN may enhance the conduction rate through the accessory pathway, leading to AF becoming VF.
All the following inhibit the AVN:
Digoxin / Metoprolol / Adenosine / Verapamil (worst)
Flecainide is a sodium channel blocker and therefore may be used.