c a r d i o

Question 1

what are the causes of bradycardia

Answer 1

DIVISIONS

drugs = ABCD
ischaemia or infarction = inferior MI
Vagal hypertonia = athletes, vasovagal syncope, carotid sinus syndrome
Infection = viral myocarditis, RF, infective endocarditis
Sick sinus syndrome
Infiltration = restrictive or dilated cardiomyopathy = MD, amyloid
O - hypothyroidism, hypokalaemia or hyper, hypothermia
Neuro = increased ICP
septal defect - primum ASD
surgery or catheterisation

Question 2

how are bradycardias classified

Answer 2

1. Sinus bradycardia
2. First degree heart block: PR > 200ms
3. Second degree heart block
    Wenkebach / Mobitz I
    Mobitz II
4. Complete heart block
    Junctional: narrow QRS @ ~50bpm
    Ventricular: broad QRS @ ~40bpm

Question 3

management of bradycardias if asymptomatic

Answer 3

If asymptomatic and rate >40: no Rx needed

Question 4

management of bradycardias if symptomatic or rate less than 40bpm

Answer 4

1. Rx underlying cause: e.g. drugs, MI
2. Medical
    Atropine 0.6–1.2g (max 3g) IV  Isoprenaline IVI
3. Pacing: External

Question 5

what’s the elective management for bradycardias

Answer 5

permeant pacing

Question 6

what are signs of bradycardia

Answer 6

signs may indicate instability: Systolic BP < 90 mmHg, HR < 40 bpm, poor perfusion, and poor urine output, ventricular arrhythmias requiring suppression or heart failure.

Question 7

sinus node dysfunction can lead to…

Answer 7

sinus bradycardia, sick sinus syndrome (tachy-brady), sinus arrest alone or as part of vasovagal syncope.

Question 8

what ECG changes confirm sinus bradycardia

Answer 8

There is a slow rate but every QRS is preceded by a p wave.

Question 9

what is 1st degree HB characterised by

Answer 9

PR interval greater than 0.2s

no specific treatment required

Question 10

pt with 1st degree AV block on digoxin.. you should check for..

Answer 10

check for toxicity - remember drugs is a cause of bradycardias - digoxin can cause

Question 11

what is second degree AV block characterised by

Answer 11

progressive lengthening of PR interval followed by failure of the atrial impulse to conduct to the ventricles

Question 12

when does second degree AV block occur

Answer 12

occurs in young fit pts with high vagal tone - can see during night if monitored

It can occur quite frequently following inferior MI and rarely proceeds to complete heart block.

Question 13

what is the management for second degree HB

Answer 13

No specific therapy is indicated. Higher degrees of AV block should be looked for if patients present with syncope or dizziness.

Question 14

what is second degree AV block Mobitz type II characterised by

Answer 14

characterised by a constant PR interval followed by sudden failure of a P wave to be conducted to the ventricles.

ECG of second degree heart block with 2 p waves for every QRS.

Question 15

how is second degree Mobitz type II managed

Answer 15

In the absence of a recent acute coronary event, permanent pacing should be arranged (if drugs have been excluded).

Question 16

complete/ third degree AV block is characterised by

Answer 16

no conduction from the atria to the ventricles and therefore AV dissociation. There is no relationship between the P waves and QRS complexes

Question 17

where can complete AV block occur

Answer 17

This block can occur above the AV node at the His region (narrow complex escape and usually well tolerated such as congenital complete heart block) or beneath the AV node with broad complex escape (not well tolerated). In can also be intermittent therefore look for ECGs with trifascicular or bifascicular block (RBBB, left axis deviation with or without prolonged PR interval) and alternating LBBB and RBBB.

Question 18

describe the treatment of severe hyperkalaemia cause complete AV block and in haemodyamically unstable pt

Answer 18

severe hyperkalaemia (can be treated with IV calcium chloride - 10 ml of 10% solution over 3-5 minutes). In the haemodynamically unstable patient, atropine can be administered (600 μg to a maximum of 3 mg). Isoprenaline administered at a rate of 5 μg/min can be tried.

Question 19

how is third degree heart block managed

Answer 19

Urgent permanent pacing is indicated, and should be considered within 24 hours, in all patients except those with a reasonable likelihood of recovery of conduction - such as in patients with a recent coronary event.

Question 20

describe the pathology behind AF

Answer 20

LA loses refractoriness before the end of atrial systole.

 → recurrent, uncoordinated contraction @ 300-600bpm

Question 21

Why af can trigger HF

Answer 21

Atrial contraction responsible for ~25% of CO

often triggers heart failure

Question 22

What are the common causes of AF

Answer 22

IHD
 Rheumatic heart disease
 Thyrotoxicosis
 Hypertension

Question 23

What are other cause of AF

Answer 23

 Alcohol
 Pneumonia
 PE
 Post-op
 Hypokalaemia
 RA

Question 24

what are the sx associated with AF

Answer 24

Asympto
 Chest pain
 Palpitations
 Dyspnoea
 Faintness

Question 25

what clinical signs are associated with AF

Answer 25

Irregularly irregular pulse  Pulse deficit: difference between pulse and HS  Fast AF → loss of diastolic filling → no palpable pulse  Signs of LVF

Question 26

what investigations are required

Answer 26

ECG  FBC, U+E, TFTs, Trop  Consider TTE: structural abnormalitie

Question 27

is an echo done in suspected AF

Answer 27

Perform if suspected structural heart disease (on the basis of symptoms or examination finding of a murmur or signs of heart failure). 2. Where a rhythm control strategy (cardioversion) is being considered 3. Baseline echocardiogram required to inform long term management

Question 28

cardiac monitoring in paroxysmal AF - how is it done

Answer 28

If paroxysmal (intermittent) AF is suspected, further cardiac monitoring is recommended. Short term cardiac monitoring with a 24 hour cardiac monitor is considered the first line investigation, and is universally available to clinicians without requiring Cardiology input. The AliveCor app/cardiac monitor is also available in primary care where repeated snap shots of rhythm over time can increase diagnostic yield.

Question 29

what are the types of AF

Answer 29

``` acute - less than 48 hrs paroxysmal - self limiting, 7 days our less persistent - more than 7 days permenant - all the time atrial flutter ```

Question 30

what are the 3 principles of management in AF

Answer 30

1. Anticoagulation to prevent stroke 2. Rate control 3. Rhythm control

Question 31

what does the CHA2DS2VaSc score assess and what do the scores relate to

Answer 31

quantify risk of stroke or systemic embolism The score estimate an adjusted stroke rate per year score of 2 or more = significant risk = anticoag score of 1 in men - intermediate = consider anticoagulant consider bleeding risk score of - - low risk = no anticoagulation required score 1 or 0 in women is low = no anticoagulants

Question 32

what score is used to assess bleeding risk

Answer 32

HAS-BLED It estimates the rate of major bleeds per 100 patient years a) Uncontrolled hypertension (SBP>160mmHg) b) Poor INR control (“labile INR”), as measured by time-in-therapeutic range (TTR) c) Concurrent medication (aspirin, NSAIDs) d) Harmful alcohol consumption (>14 units per week) score is not intended to withhold anticoagulation, but to inform discussions and enable identification and optimisation of reversible risk factors for bleeding, including:

Question 33

what are DOACs and why are they preferred

Answer 33

direct oral anticoagulants They do not require regular testing of levels compared to the INR monitoring of warfarin. There are no restrictions on food or alcohol. lower rates of bleeding to warfarin (brain and GIT)

Question 34

How do DOACS work

Answer 34

inhibit factor Xa (apixiban, rivaroxaban and edoxaban) or direct thrombin inhibitor (dabigatran) to reduced thromboembolic events.

Question 35

describe rate control in AF

Answer 35

REFER TO WORKBOOK FLOW CHART page 36

Question 36

describe rate control in AF, how does it work

Answer 36

slow the heart response to AF by slowing conduction at the Av node to reduce ventricular conduction and therefore heart rate. look at diagram in work book

Question 37

what is SVT

Answer 37

rate greater than 100bpm QRS width less than 120ms narrow complex tachycardia

Question 38

ddx for SVT

Answer 38

``` Sinus tachycardia 2. Atrial  AF  Atrial flutter  Atrial tachycardia 3. AV nodal re-entry tachycardia 4. AV re-entry tachycardia ```

Question 39

describe the physiology behind SVT management

Answer 39

SVT most people have AVNRT or AVRT these arrhythmias depend on AV nodal contraction and therefore can be terminated by transiently blocking AV nodal conduction

Question 40

rapid broad complex tachycardia after STEMI is nearly always

Answer 40

VT

Question 41

How is VT with broad QRS signal following STEMI managed

Answer 41

sustained VT who are haemodynamically compromised cardioversion is indicated (synchronised 150 – 200 joule shock with a biphasic defibrillator). Suppression can be achieved with β-blockers . Amiodarone can be tried (300 mg IV over a few minutes, followed by 900 mg over 24 hours). An alternative is lidocaine (50 - 100 mg over 3 - 5 minutes), which may be repeated after 5 minutes. No more than 200 - 300 mg should be given in one hour.

Question 42

what is the first line treatment of SVT in haemodynically stable pts

Answer 42

vagal manoeuvres - breath holding and valsava manoeuvre

Question 43

how do you do the valsalva manoeuvre

Answer 43

having the patient bear down as though having a bowel movement or blowing hard into a syringe to move the plunger)

Question 44

how do vagal manoeuvres act in svt

Answer 44

all slow conduction in the AV node and can potentially interrupt the re-entrant circuit.

Question 45

how is the carotid sinus massage done. what must be done before and why? how long to wait before trying other side

Answer 45

Carotid massage is another vagal manoeuvre that can slow AV nodal conduction. Massage the carotid sinus for several seconds on the non-dominant cerebral hemisphere side. This manoeuvre is usually reserved for young patients. Due to the risk of stroke from emboli, auscultate for bruits before attempting this manoeuvre. Do not perform carotid massage on both sides simultaneously. Wait at least 10 seconds before trying the other side

Question 46

what can be used if SVT not terminated by vagal manoeuvres

Answer 46

1. intravenous adenosine or calcium channel blockers. Adenosine is a short-acting drug that blocks AV node conduction; it terminates 90% of tachycardias due to AVNRT or AVRT. It is given as a rapid IV bolus followed by a saline flush

Question 47

what are the SE of adenosine, when managing SVT

Answer 47

Adenosine has a very short half-life. It may produce chest discomfort (which the patient should be warned about), transient hypotension and flushing. It should be avoided in patients with significant reversible airways disease. The crash trolley should be next to the patient when administering this drug in the unlikely event of significant bradyarrhythmia or more rarely tachyarrhythmia.

Question 48

If the tachycardia continues despite successful induction of at least some degree of AV blockade, the rhythm is almost certainly...

Answer 48

atrial tachycardia or flutter AVRT is excluded and AVNRT is unlikely

Question 49

synchronised cardioversion following sedation is used in

Answer 49

starting at 150J can be used immediately in patients who are hypotensive, have pulmonary oedema, have chest pain with ischaemia, or are otherwise unstable.

Question 50

what are the commonest bacterial causes of IE

Answer 50

streptococci viridans - | staph aureus - IVDU

Question 51

IE occurring ‘early’ (up to 1 year) after the implantation of prosthetic heart valves is thought to be due to perioperative contamination and is mainly caused by

Answer 51

staphlococci esp coagulase negative

Question 52

‘Late’ prosthetic valve infections are commonly due to

Answer 52

viridans streptococci, Staphylococcus aureus and coagulase- negative staphylococci.

Question 53

Lx in IE

Answer 53

key investigations = blood cultures (at least 3 cultures over hours, at 3 different sites) and echocardiogram (ToE more sensitive TTE) ``` ● Full blood count ● ESR and CRP ● U&Es ● Liver function tests ● Urine dipstick analysis and MSU for microscopy/culture ● Chest X-ray ● ECG ```

Question 54

what is the major diagnostic criteria for IE

Answer 54

major vs minor major = endocardial involvement, positive blood cultures, positive echo findings, new valve regurgitation, dehiscence of prosthesis

Question 55

describe the minor diagnostic criteria for IE

Answer 55

predisposing valve or cardiac abnormality IVDU pyrexia more than 38 embolic phenomenon vasculitic phenomenon blood cultures with organism grown but not meeting major criteria echo findings suggestive but not meeting major criteria

Question 56

what is the management for IE

Answer 56

IV Abx via tunnelled central venous line streptococci = benzylpenicillin or vancomycin if pen allergy plus gentamicin enterococci = amoxicillin or vancomycin if pen allegory and gentamicin staph = fluclox or vancomycin if pen allergic or MRSA plus gentamicin

Question 57

what should be monitored in IE

Answer 57

echocardiogram once weekly to assess vegetation size and to look for complications - valve destruction, abscess intracardiac ECG twice a week to look for conduction disturbance

Question 58

when is surgery indicated in IE

Answer 58

moderate to severe cardiac failure due to valve compromise valve dehiscence valve obstruction paravalvular abscess

Question 59

management of HTN urgency or emergency

Answer 59

1. sodium nitroprusside 2. labetalol 3. GTN 4. Esmolol

Question 60

oral regime for HTN urgency

Answer 60

amlodipine diltiazem lisinopril

Question 61

control of phaechro HTN

Answer 61

alpha and beta blockers commonly use phenoxybenzamine then use beta never start with beta adrenergic blocker first

Question 62

aortic stenosis murmur describe it

Answer 62

ejection systolic murmur radiating to neck or carotid

Question 63

where to listen for aortic stenosis murmur

Answer 63

2nd ICS right side

Question 64

aortic regurgitation murmur

Answer 64

1. early diastolic murmur left sternal edge

Question 65

aortic regurgitation associated with and managed by

Answer 65

collapsing pulse, De Musset’s sign = head bobbing ACEi to reduce after load + surgery if indicated

Question 66

mitral regurgitation murmur is

Answer 66

pan systolic blowing murmur hears over mitral area 5th ICS midclavicular line radiates to axilla