Cardiology Flashcards
What is the physiology behind VF?
Rapid, uncoordinated contraction of ventricles causing QRS to become irregular.
How is VF managed?
Desynchronised cardioversion and CPR in between shocks.
What is pharmacological intervention can be used after 3 unsuccessful shocks to manage VF (refractory VF)?
IV adrenaline (1mg 1:10000) and amiodarone (300 mg).
What is the physiology behind VT? What is seen on ECG?
Rapid contraction of ventricles means body isn’t perfused correctly. Causes a monomorphic broad complex tachycardia.
How do we manage a haemodynamically stable patient in VT?
300 mg amiodarone over 20 minutes then 900 mg over 24 hours.
How do we manage a haemodynamically unstable patient in VT?
chest compressions at a rate of 100-120/minute (30:2 ratio) and delivery of DC cardioversion.
What is seen on ECG for Torsades?
Polymorphic broad complex tachycardia.
How is Torsade’s managed?
2g IV magnesium sulphate
What ECG abnormalities are associated with hypomagnesaemia?
Prolonged QT interval which can convert into Torsade’s.
How do we manage a sinus bradycardia with haemodynamic compromise?
IV atropine 500 micrograms every 3-5 minutes up to 3mg total.
If this fails, convert to transcutaneous pacing.
What medication can be used to manage bradycardia once 3mg of atropine has been used but transcutaneous pacing is not available?
IV isoprenaline
What is the biggest SE of atropine 6-12 hours after administration?
Agitation.
What are the ECG signs of AF?
Irregularly irregular rhythm and lack of p waves.
If someone presents in AF with haemodynamic compromise how is it managed?
Synchronised cardioversion.
Can you cardiovert someone who presents, haemodynamically stable, in AF whose symptoms started 3 days ago?
No - 48 hours is the cut off for cardioversion due to risk of clot. These patients need to be anticoagulated before they can be cardioverted.
What medications can be used for rate control of AF?
1st line is beta blockers (diltiazem if CI),
Can also use digoxin if these are unsuccessful (250mg loading dose followed by 250 mg 6 hours later and then oral OD doses).
What medications can be used to rhythm control someone in AF?
Amiodarone (dangerous long-term SEs),
Class 1c antiarrhythmics - flecainide/propafenone - which are used as ‘pill in pocket’ to take when patients become symptomatic (can only be used in someone with a structurally normal heart).
If someone in AF has a regular HR what is the other pathology occurring?
3rd degree (complete) heart block. Ventricle isn’t receiving atrial signals so irregular rhythm isn’t transmitted so there is a normally ventricular rate.
What is Brugada Syndrome? What are the signs on ECG?
tachyarrhythmias caused by Na channel pathology, often familial.
ECG: concavity and elevation of ST segment in V1-3 and T waves inversion.
Which of the following is associated with life-threatening arrhythmias in someone with Brugada syndrome?
a) Hypotension
b) Hyponatraemia
c) Fevers
C- fevers, accentuating the ECG signs and causing ventricular arrhythmias.
SVT can be categorised into 3 different types, what are these?
- AVNRT (atria-ventricular node re-entry tachycardia)
- Atrial flutter
- Accessory pathways (WPW)
What is seen on ECG for AVNRT? How is it managed?
Narrow complex tachycardia with no P waves.
Management:
1) vagal manoeuvres
2) Adenosine (6, 12, 18)
3) If unsuccessful try synchronised cardioversion (or if haemodynamically compromised)
Why can we not prescribe adenosine for atrial flutter? How do we manage it?
DOES NOT respond to adenosine as it is independent to the ventricle and adenosine blocks AV node (so if you gave it the atria would continue to fire).
Managed with beta blockers and if this is unsuccessful may need synchronised cardioversion.
What is seen on ECG for atrial flutter? What is the rate?
Sawtooth baseline.
Atrial rate around 300bpm, ventricular rate around 150bpm (every other beat transmitted).
What is the signs of an accessory pathway on ECG? How is it managed?
Preexcitation (delta waves), shortened PR.
Manage the same as AF.
What is sick sinus syndrome? What are the symptoms?
Bradycardia, prolonged heart beats, and arrhythmias, disfunction of SA node.
Dizziness, syncope, SOB, fatigue
What is classed as a prolonged QT interval for men and women?
> 460 in women, >440 in men
Is an Ejection fraction <50% associated with systolic or diastolic heart failure?
Reduced ejection fraction heart failure is Systolic dysfunction (LV can’t contract properly to squeeze out blood).
Preserved ejection fraction heart failure is an EF over what %? What is this also known as?
EF >50%, aka diastolic heart failure (LV unable to fill properly).
How do we improve mortality for heart failure patients with a reduced EF?
BASH: betablocker, ACEi, spironolactone, hydralazine.
Can medications improve mortality for pts with HFpEF (diastolic failure)?
No - manage comorbidities.
Is a 4th heart sound pathological?Why?
YES - forceful atrial contraction against a stiff hypertrophic LV.
What is cor Pulmonale? Signs on ECG?
Right heart failure secondary to COPD.
P pulmonary waves (pulmonary HeTN causing right atrial enlargement)
Thyrotoxicosis and anaemia are examples of what type of heart failure?
High output cardiac failure (increased CO to compensate for higher demand)
What is first line management of stable angina?
GTN and beta blockers
ACS management?
- 300 mg aspirin
- morphine (pain)
- nitrates
- oxygen (only if not saturating)
- metoclopramide (if feeling nauseous)
MI of what artery puts the pt at an increased risk for rupture of their interventricular septum?
What are the complications of this?
What murmur is heard?
LAD - interruption of septal supply.
cardiogenic shock, haemodynamic compromise, biventricular failure. A harsh holosystolic murmur may be heard.
How do you manage a pt with an interventricular septal rupture?
Aim is to reduce afterload.
Medical: Nitroprusside (decreased HeTN in acute heart failure).
Surgical: (intra-aortic balloon pump)
What artery is taken for use in bypass graft on LAD?
Internal mammary.
Aortic regurgitation is associated with which murmur? What other signs may be seen?
Diastolic decrescendo murmur at the left sternal border.
Quincke’s sign (pulsating of nail beds), collapsing pulse (radial pulse disappears when raising arm due to incompetence and backflow of blood across valve).
Aortic Stenosis is associated with what murmur?
Ejection systolic murmur at the second intercostal space.
What less typical murmur can aortic stenosis cause?
Can also cause a musical pansystolic murmur at the apex (Gallavardin phenomenom).
This is due to vibrations that travel from the calcified valve.
This murmur DOES NOT radiate to the axilla.
What clinical signs are associated with aortic stenosis?
Exertional breathlessness, low-volume pulse, narrow pulse pressure, quiet S2.
What makes aortic stenosis severe?
Valvular area <1cm, elevated pressure gradient >40mmHg.