cv middle tier Flashcards
bradycardia
- put a speed on it
- symptoms
- who is it normal for
- Less than 60bpm daytime and 50bpm night
- Usually asymptomatic
- Normal in athletes due to increased vagal tone and so increased parasympathetic activity
tachycardia
- put a speed on it
- two types
- More than 100bpm
- Supraventricular tachycardias - arise from atrium / AV junction — Atrial fibrillation/ atrial flutter
- Ventricular tachycardias - arise from ventricles
atrial fibrilation
- irregular?
- put a speed on it
- what is happening
- irregularly irregular - chaotic, atrial spasm
- 300-600bpm
- rapid activation of atria by multiple meandering re-entry wavelets. AV node responds intermittently , only a portion of impulses conducted on→ irregular ventricular rate
atrial fibrillation
- persistent
- permanent
- paroxysmal
- recurrent
- acute
- Persistent = continuous for 7days+, not self terminating
- Permanent = long term
- paroxysmal = self-terminating within 7 days
- Recurrent: two + episodes
- Acute = onset on last 48h
atrial fibrillation
- gender
- commonness
- age
- m>f
- most common arrythmia
- old
atrial fibrillation risk factors
- 60y+
- Diabetes
- Hypertension
- Coronary artery disease
- Previous MI
- Structural heart disease (valve/congenital defects)
atrial fibrillation causes/ risk factors
cardiac
- Increased atrial pressure, increased atrial mass, atrial fibrosis/ inflammation/ infiltration
- Hypertension
- Heart failure
- MI
- Coronary artery disease
- structural heart disease inc Valvular
- Cardiac surgery
- Cardiomyopathy
- Rheumatic heart disease
non cardiac
- Acute excess alcohol intoxication, exposure to caffeine tobacco etc
- hyperthyroidism
- chest infection
- age
- DM
atrial fibrillation symptoms
- None at all /
- Dizziness
- Palpitations
- Syncope
- Chest pain
- Heart failure
- Fatigue
atrial fibrillation ecg
- Rapid, irregular QRS,
- Absent p waves - jaggedy
- No steady isoelectric baseline
atrial fibrillation/ flutter treatment
treat precipitating cause
control ventricular rate
- beta blockers
- CCB
- digoxin
- amiodraone
- lidocaine
restore sinus rhythm
- cardioversion (electricla DC shock)- defibrillator
catheter based therapy – ablate/ destroy cells
do CHADVASC (Stroke risk) to see if anticoagulation medication needed
why is verapamil (phenylalinine CCB) more effective than amlopifine (dihydropiridine CCB)?
dont act on calcium channels at rest
which beta blocker is best for post MI arrythmias and why
propanolol
additional quality of blocking sodium channels
cardioversion is associated with what risk
so what is given alongside
risk of thromboembolism, so need to give LMW heparin
lidocaine action
blocks the inactivation gate of Na channels so prolongs inactivation meaning higher depolarization threshold and early action potentials less likely to get through
for arrythmias (vent trach)
digoxin action
Slows HR
Increases contractility
atrial fibrillation complications
Sudden death Syncope (fainting) Heart failure Chest pain Dizziness Palpitations Stroke
atrial flutter
- irregularity
- put a speed on it
- what is happening
- regularly irregular, organised but rapid
- 250-350bpm
- Due to re-entry circuit in RA from AV back to sinus
atrial flutter ecg
“saw tooth” ECG
Narrow tachycardia
Flutter waves
.
.
atrial flutter symptoms
Dizziness breathlessness Palpitations Syncope Chest pain Heart failure Fatigue
heart block
- brady/tachy
- what is happening
- which part of ecg is changed (what is normal)
- brady
- Conduction issue- signals not properly propogated from SAN to AVN to His-Purkinje system
- PR interval. normal is 120-200ms. heart block= greater
first degree heart block symptoms
asymptomatic
second degree mobitz type 1 symptoms
lots asymptomatic
light headed
dizzy
syncope
second degree mobitz type 2 symptoms
less likely to be asymptomatic light headed dizzy syncope chest pain SOB postural hypertension
third degree heart block symptoms
syncope fatigue - extreme chest pain breathlessness confusion palpitations brady
first degree heart block
- what is it
- causes
- 1:1 a:v (each is conducted but slower than normal, no dropped beats )
- PR interval prolonged, PR intervals are constant
- block in AV node – delay
- Hypokalemia
- Myocarditis
- Inferior MI
- AVN blocking drugs (B blockers, CCB, digoxin)
second degree heart block - mobitz type 1
- aka
- what is it
- causes
- wenckebach
- AVnode issue
- PR interval increases progressively, then a failure of a P wave proper conduction so a ‘dropped’/missing QRS wave (then reset)
- AVN blocking drugs (B blockers, CCB, digoxin)
- inferior MI
heart block treatment and when
only need treatment if symptomatic
- transcutaneous pacing (TCP) to restore heart rate (temporary)
- pacemaker (permenant ) may follow
second degree heart block- mobitz type 2
- what is it
- causes
- Distal conduction issue
- PR interval lengthened but no PR interval change - it is constant. then a beat is dropped (missing QRS-P wave not conducted)
Anterior MI mitral valve surgery SLE, lyme disease rheumatic fever
third degree heart block
- what is it
- causes
- 3rd degree is no relation between a and v - they contract independently- so P and QRS appear independent.
- Constant p to p intervals. Constant q to q intervals. They are constant with themselves, but independent of the other
- Large space between each QRS.
- P waves may be buried in the QRS complex so can be hard to distinguish - look for intervals as said above
Structural heart disease ischaemic heart disease hypertension endocarditis lyme disease
bundle blocks
- a:v ratio
- what is the pathology
- ecg looks like?
- 1:1
- No depolaristation down L or R branch so one side of the heart is delayed as the depolarisation has to spread across the septum from the other ventricle
- Broad QR
LBBB
ecg
sound
causes
wiLLiam
W in v1
M in v6
L eaving each other
Reverse splitting of second heart sound
- Ischaemic heart disease
- aortic valve disease
RBBB
ecg
sound
causes
maRRow
M in v1
W in v6
R eaching towards each other
Splitting of second heart sound
- Pulmonary embolism
- ischaemic heart disease
- atrial/ ventricular septal defect
supraventricular tachycardia
- age
- arises from where
- Young patient (12-30)
- Arises from atria / atrioventricular junction
slow fast AVNRT means?
atria contract slowly then fast in different cycles
AVNRT = AV nodal reentrant tachycardia
wolf parkinson white pathophysiology
AVRT
- Accessory pathway = bundle of Kent. bypasses the AV node (which normally slows/delays conduction) so this causes early abnormal depolarisation of part of the ventricle (=pre-excitation)
- Pre excitation = short PR interval, wide QRS
- Circuit loop = down normal pathway (AVN) as accessory bundle of kent is in refractory period, depolarizes ventricles and up bundle of kent accessory pathway (now out of refractory period) so impulse back to atria and down AVN again – reentry circuit
this is AVRT (AV reentrant tachycardia )- not AVNRT - no node!
AVNRT/AVRT treatment
- Hold breath / carotid massage
- Adenosine (temporary rapid heart block - stops loops)
- Surgical ablation of accessory pathway(AVRT) / modification of slow pathway (AVNRT)
- pacemaker
AVNRT/AVRT
- supravent/ vent
- tachy/brady
supraventricular tachy
AVNRT pathophysiology
- AV nodal reentrant tachy AVNRT:
- One of the conducting pathways in AV node is fast, the other is slow
- -Fast one is used preferentially. If an impulse is early, the fast one may still be in the refractory period, so the slow one is used and propagates signal to ventricles
- -This impulse travels back up fast pathway (now out of refractory period) and goes down slow pathway again (now out of refractory period)
- This sets up re-entrant loop
prolonged QT syndrome
- =
- causes
- presentation
Ventricular repolarization (QT interval) is greatly prolonged
Congenital
- Jervell-lange-nielsen
- romano-ward
Acquired
- Hypokalemia
- hypocalcaemia *
- drugs (amiodarone (antiarrhythmic), antidepressants)
- bradycardia
- acute MI
- diabetes
Syncope
palpitations
aortic aneurysm risk factors
Hypertension Age Smoking bicuspid/unicuspid aortic valves Atherosclerosis Renal failure Previous aneurysm Family history Male COPD Hyperlipidemia
aortic dissection risk factors/ causes
Male
Age
Atherosclerosis
Genetics
Inherited Degenerative Atherosclerotic Inflammatory Trauma
what is aortic aneurysm
where
types
- permanent dilation of artery to twice the normal diameter
- can be abdominal or thoracic
- can be true (ruptured or unruptured) or false (psuedoaneurysm)
true aneurysm
Abnormal dilation involves all layers of arterial wall
Loss of elastic lamellae
Smooth muscle cell loss
Is abdominal aortic aneurysm AAA true or false
true
two types of true aortic aneurysm
- symptoms
unruptured
- often asymptomatic, picked up with routine xray etc
- Pain in abdomen /back/ loin/ groin
- Pulsatile abdominal swelling
ruptured
- Pronounced pulsatile abdominal swelling
- Collapse
- Hypotension
- Tachycardia
- Anemia
- Sudden death
what makes a person more likely for their aortic anuerysm to rupture
more likely if
high BP,
female,
smoker,
family history
psuedoaneurysm / fake aneurysm
collection of blood in the adventitia (/ tunica externia , outer layer) -
like a pocket of blood causing a bulge out the side of the vessel rather than the whole wall thickenness being deviated