Cardiology Flashcards
Commonest cardiomyopathy
Dilated
What is the pathophysiology behind dilated cardiomypathy?
Systolic dysfunction
Why/When do you hear third heart sound S3?
Filling of the ventricle
Dilated cardiomyopathy, mitral regurg, constrictive pericarditis,
Why/when do you hear S4?
Caused by atrial contraction against a stiff ventricle (coincides with p wave)
e.g. in Ao stenosis, HOCM, HTN
What causes S1?
Closure of mitral/tricuspid valve
What causes S2?
Closure of Ao/pulmonary valves
How does ANP work?
released in response to increased blood volume / HTN
Causes vasodilation:
- natriuretic, i.e. promotes excretion of sodium
- lowers BP
- antagonises actions of angiotensin II, aldosterone
What is associated with variability in intensity of S1?
Complete heart block
What is associated with loud S1
Mitral stenosis
Describe mitral regurg heart sounds
Quiet S1
Widely split s2
S3
most common cause Infective endocarditis?
Staph aureus
what is the commonest cause of infective endocarditis in prosthetic valve (in first two months post surgery)? + indwelling lines
Staph epidermidis / coagulase negative staph
give ECG changes in digoxin toxicity?
bradycardia or AV block a short QT interval a prolonged PR interval ST depression inverted T waves
What ECG changes are pericarditis associated with?
ST elevation
PR depression
Chest pain following MI 6 weeks. What is the likely cause
Dressler’s - autoimmune pericarditis
What type of pulse seen in hypertrophic cardiomypathy?
Jerky pulse
Causes of left axis deviation?
left anterior hemiblock
left bundle branch block
inferior myocardial infarction
Wolff-Parkinson-White syndrome* - right-sided accessory pathway (GOES RIGHT TO LEFT)
hyperkalaemia
congenital: ostium primum ASD, tricuspid atresia
minor LAD in obese people
Causes of right axis devation?
right ventricular hypertrophy left posterior hemiblock lateral myocardial infarction chronic lung disease → cor pulmonale pulmonary embolism ostium secundum ASD Wolff-Parkinson-White syndrome* - left-sided accessory pathway normal in infant < 1 years old minor RAD in tall people
N.b. WPW usually LAD - if Q asks
What is cardiac axis? What is normal?
The axis of the ECG is the major direction of the overall electrical activity of the heart
+90 to -30
What is the mechanism of amiodarone?
K+ channel blocker inhibiting repolarisation and prolonging action potential
[also blocks other channels -
(class III antiarhythmic)
Why are loading doses used with amiodarone?
Long half life
What is the mechanism of class 1 antiarrhythmics? Give the types/ examples for each
Sodium channel blockers (prevent influx of sodium into myocytes –> slower depolarisation [decreasing the slope in phase 0])
1a: procainamide
1b: lidocaine
1c: flecainide
What is the mechanism of class II antiarhythmics?
beta-blockers (e.g. metoprolol or propranolol)
What is the mechanism of class III antiarhythmics? How do they affect ECGs?
K+ channel blockers inhibiting repolarisation and prolonging action potential
Wider/longer QRS and long QT (potential for other arrhythmias)
E.g. amiodarone