Cardiology Flashcards
What is paroxysmal nocturnal dyspnoea?
Suddenly waking up at night with a severe attack of shortness of breath and cough
What is the first line medical treatment for heart failure (ABAL)?
ACE inhibitor (up to 10mg OD)
Beta blocker (up to 10mg OD)
Aldosterone antagonist when symptoms not controlled with A and B (spironolactone or eplerenone)
Loop diuretics improves symptoms (e.g. furosemide 40mg OD)
What is the monitoring requirement for diuretics, ACE inhibitors and aldosterone antagonists?
U&Es
What drug should be avoided in patients with valvular heart disease until indicated by a specialist?
ACE inhibitors
What is the difference between systolic and diastolic heart failure?
Systolic = impaired left ventricular contraction
Diastolic = impaired left ventricular relaxation
What BNP requires an urgent specialist referral?
A BNP over 2000
What is cor pulmonale?
Right sided heart failure caused by respiratory disease
What is the pathophysiology of cor pulmonale?
Increased pressure and resistance in the pulmonary arteries (pulmonary hypertension) results in the right ventricle being unable to effectively pump blood out of the ventricle and into the pulmonary arteries.
Back pressure of blood in the right atrium, the vena cava and the systemic venous system
What are the causes of cor pulmonale?
COPD
PE
Interstitial lung disease
CF
Primary pulmonary hypertension
What are the main symptoms of cor pulmonale?
Often asymptomatic
SOB
Peripheral oedema
Increased breathlessness on exertion
Syncope
Chest pain
What are some signs of cor pulmonale?
Hypoxia
Cyanosis
Raised JVP
Peripheral oedema
Third heart sound
Murmurs (e.g. pan-systolic in tricuspid regurgitation)
Hepatomegaly
What is the management of cor pulmonale?
Treat symptoms and underlying cause
What causes a third heart sound?
Rapid ventricular filling
Cause chord tendineae to twang
Either because they are young and healthy or because the ventricles are stiff and weak and so reach their limit much faster than normal
What causes a fourth heart sound?
S4 is heard directly before S1.
Always abnormal, rare
Stiff or hypertrophic ventricle
Caused by turbulent flow from an atria contracting against a non-compliant ventricle
What are the locations for auscultation of the different heart valves?
Pulmonary: 2nd ICS left sternal border
Aortic: 2nd ICS right sternal border
Tricuspid: 5th ICS left sternal border
Mitral: 5th ICS mid clavicular line
How do you grade a murmur?
- Difficult to hear
- Quiet
- Easy to hear
- Easy to hear with a palpable thrill
- Can hear with stethoscope barely touching chest
- Can hear with stethoscope off the chest
What valvular disease causes hypertrophy?
Stenosis:
Mitral stenosis causes left atrial hypertrophy
Aortic stenosis causes left ventricular hypertrophy
What valvular disease causes dilatation?
Regurgitation
Mitral: left atrial dilatation
Aortic: left ventricular dilatation
What can cause mitral stenosis?
Rheumatic heart disease
Infective endocarditis
What does a mitral stenosis murmur sound like?
Mid-diastolic, low pitched rumbling (low velocity of blood)
What is mitral stenosis associated with?
Malar flush (due to rise in CO2 and vasodilation)
AF
What does a mitral regurgitation murmur sound like?
pan-systolic, high pitched whistling (high velocity of blood)
Radiates to left axilla
May heart a third heart sound
What is mitral regurgitation associated with?
Congestive Cardiac failure (reduced ejection fraction and backlog of blood)
What can cause mitral regurgitation?
Idiopathic weakening of the valve with age
Ischaemic heart disease
Infective endocarditis
Rheumatic heart disease
Connective tissue disorders
What does an aortic stenosis murmur sound like?
Ejection systolic, high pitched murmur
Crescendo-decrescendo
What are some other signs of aortic stenosis?
Radiates to carotids
Slow rising pulse and narrow pulse pressure
Exertional syncope
Causes of aortic stenosis?
Idiopathic age related calcificaiton
Rheumatic heart disease
What does an aortic regurgitation murmur sound like?
Early diastolic, soft murmur
Associated with a Corrigan’s pulse (collapsing pulse) - a rapidly appearing and disappearing pulse at carotid as the blood is pumped out by the ventricles and then immediately flows back through the aortic valve.
Results in heart failure
Can also cause an ‘Austin-flint’ murmur (heart at apex and is an early diastolic rumbling murmur)
Causes of aortic regurgitation?
Idiopathic age related weakness
Connective tissue disorders
What are the four cardiac arrest rhythms?
Shockable: ventricular tachycardia and ventricular fibrillation
Non shockable: Pulseless electrical activity or asystole
How do you manage supraventricular tachycardias?
Vagal manoeuvres
Carotid sinus massage
Adenosine (or alternatively verapamil)
Direct current cardio version may be required
How do you manage ventricular tachycardia?
If stable: amiodarone infusion
If unstable: 3 shocks and then consider amiodarone
What causes atrial flutter?
Re-entrant rhythm
Sawtooth appearance on ECG
What are some associated conditions with atrial flutter?
Hypertension
Ischaemic heart disease
Cardiomyopathy
Thyrotoxicosis
What causes supra ventricular tachycardias?
Re-entrant electrical signals. Results in a fast, narrow complex tachycardia
How does adenosine work?
Slows cardiac conduction primarily through the AV node - resets it to sinus rhythm.
When should you avoid adenosine?
Asthma/COPD/Heart failure/heart block/severe hypotension
What is the extra pathway in Wolff-Parkinson White Syndrome called?
Bundle of Kent
What ECG changes do you see in Wolff-Parkinson White?
Short PR interval
Wide QRS complexes
Delta wave (slurred upstroke on the QRS complex)
What can cause a prolonged QT?
Long QT syndrome
Medications (antipsychotics, citalopram, flecainide, stall, amiodarone, macrolide antibiotics)
Electrolyte disturbance (hypokalaemia, hypomagnesaemia, hypocalcaemia)
What can a prolonged QT progress to?
Torsades de pointes (which can then progress to ventricular tachycardia and cardiac arrest)
What is the acute management of Torsades de pointes?
Correct the cause
Magnesium infusion (even if normal magnesium)
Defibrillation if VT occurs
Long term management of prolonged QT syndrome?
Avoid medications that prolong the QT interval
Correct electrolyte disturbances
Beta blockers (not stall)
Pacemaker or implantable defibrillator
What is the difference between different types of heart block?
First degree: delayed AV conduction (long PR interval)
Second degree: some atrial pulses don’t make it through
- Wenkebach’s phenomenon (Mobitz type 1) = atrial impulses become gradually weaker until it does not pass through AV node and then restarts strong. See increasing PR interval and then an absent QRS complex.
- Mobitz type 2 = intermittent failure or interruption. Missing QRS complexes. Usually a ratio of P waves to QRS complexes. PR interval normal.
Third degree = Complete heart block: no observable relationship between P waves and QRS complexes
How do you treat unstable heart block or risk of systole? (Mobitz type 2, complete heart block or previous systole)
Atropine 500 mcg IV, repeated until improvement or add inotropes.
Temporary trans venous cardiac pacing or pacemaker if available
How does atropine work?
Antimuscarinic
Inhibits the parasympathetic nervous system
Side effects: pupil dilatation, urinary retention, dry eyes , constipation
How do dihydropyridine calcium channel blockers work to reduce blood pressure?
Reduce calcium ion influx into cells, increasing peripheral vasodilation
What are the two non dihydropyridine calcium channel blockers?
Verapamil
Diltiazem
How do non dihydropyridine calcium channel blockers work?
Act both peripherally and centrally: increase peripheral vasodilation and block calcium influx on SAN and AVN in the heart to reduce HR, contractility, conduction - mainly work to correct arrhythmias, less effect on CO
Where does furosemide work in the kidneys?
Na+ K+/2Cl- cotransporter Loop of Henle
How do diuretics work?
Reduce salt reabsorption in the kidneys to increase water excretion
How do ACE inhibitors work?
Work to prevent the production of angiotensin II, preventing an increase in aldosterone which would increase salt reabsorption
It also prevents breakdown of bradykinin which increases vasodilation
Where does aldosterone work?
Principle cells of the collecting ducts to increase the number of Na+/K+ pumps
What are two alpha-1 blockers?
Doxasozin or Prazosin
These block alpha receptors in the peripheral arteries increasing peripheral vasodilation
What are two non-selective beta blockers?
Labetalol and Carvediol
How do non selective beta blockers affect the RAAS system?
Inhibit beta receptors in the kidneys, reducing secretion of renin, reduced RAAS
What are three selective beta -1 blockers?
atenolol
Metoprolol
Bisoprolol
How do selective beta blockers reduce blood pressure?
Reduce cardiac output
Where is angiotensinogen made?
Liver
What converts angiotensinogen to angiotensin I?
Renin
How do class I antiarrhythmic drugs work?
Block sodium channels, decrease rate of depolarization, slowing conduction velocity
How do Class II anti-arrhythmic drugs work?
Beta-1 blockers
Depress SA node automaticity, decreasing heart rate and decreasing contractility
How do Class III anti-arrhythmic drugs work?
Block K+ channels, delaying repolarization, increasing the refractory period
How do Class IV anti-arrhythmic drugs work?
Block calcium channels during depolarization, slowing conduction and decreasing contractility
What class is Procainamide?
Class Ia (moderate) anti arrhythmic
What class is Lidocaine?
Class Ib( weak) anti-arrhytmic
What class is Flecainide?
Class Ic (strong) anti-arrhythmic
What class are the following drugs: Amiodarone, Dronedarone, Sotalol, Dofetilide?
Class III
What class are Verapamil and Diltiazem?
Class IV anti-arrhythmic drugs - calcium channel blockers during depolarisation
