Lecture notes

Question 1

which leads do you look at to determine a RBBB or LBBB

Answer 1

V1 and V6

Question 2

Ventricular cardia (wide complex)

Answer 2

Dissociated P waves

Question 3

Wide complex regular tachycardia differential

Answer 3

1. Ventricular Tachycardia
2. Supraventricular tachycardia that conducts with R or L BBB
3. Pre-excited tachycardia over an accessory pathway (Antidromic AVRT)-uncommon
4. Ventricular paced rhythm-pacemakers

Question 4

VT vs SVT with BBB

Answer 4

Compare morphology of QRS complexes in V1 or V2 and V6

Question 5

What does a RBBB look like?

Answer 5

V1: rSR’ with R’ wave is broad
V6: normally small Q wave with rapid R upstroke and small terminal S wave

Question 6

What does a LBBB look like?

Answer 6

V1 and V2: negative, initial sharp deflection
V5 and V6: postive

sharp R wave followed by rapid S wave

V6: slurred R wave, absent septal q wave, followed by inverted T wave

Question 7

VT signs

Answer 7

1. Initial R wave more than 30ms
2. Notching of downstroke of S wave (FLATTENS A BIT)
3. time interval from begin R wave to latter S wave: if more than 70ms
   all in V1 and V2

AV dissociation is DIAGNOSTIC BUT RARELY SEEN
Looking for P wave is last step in analysis of wide complex tachycard

Question 8

In which condition is fusion beats and capture beats seen?

Answer 8

slow Ventricular Tachycardia

Question 9

Look for WPW pattern

Answer 9

Could be SVT with WPW

Question 10

old MI clues

Answer 10

Q waves
scar tissue in ventricles
VENTRICULAR TACHY

Question 11

Differential diagnosis of narrow-complex regular tachycardia

Answer 11

1. Sinus tachycardia
2. Atrial flutter-flutter wave caused by rentry circuit in RA
3. AVJunctionalRentryT (AVNodalRT/AVRentryT)
4. Atrial tachycardia
5. Uncommon in adults: Junctional ectopic tachycardia

ALL CAN CAUSE A WIDE COMPLEX TACHYCARDIA IF THERE IS A BBB OR IT CONDUCTS OVER AN ACCESSORY PATHWAY

Question 12

Narrow irregular tachyarrhythmias

Answer 12

Afib
Atrial flutter/tachy plus variable AVB
Multifocal atrial tachycardia

Question 13

Wide irregular

Answer 13

AF with BBB
A flutter, variable AVB and BBB
Pre-excited AF
Polymorphic VT

Question 14

IMMEDIATE management Vtachy

Answer 14

perform an ECG then synchronised DC cardioversion

Question 15

which 2 drugs should you NOT give to patients with a WIDE complex tachy

Answer 15

Verapamil

Adenosine

Question 16

Causes of Vtachy

Answer 16

above 35: coronary artery disease
below 35: hypertrophic CM
sometimes IDIOPATHIC, young patients

Question 17

Look for underlying struct. HD

Answer 17

dilated cardiomyopathy

Question 18

look for features systemic disease

Answer 18

cardiac sarcoidosis

Question 19

which electrolyte abnormality can precipitate a Vtachy

Answer 19

K

Question 20

Medication VT

Answer 20

Beta-blocker and amiodarone(prevents Vtachy)
Consider ICD
Immunosuppressive treatment: sarcoidosis
Idiopathic: structurally normal heart, amiodarone and ICD CONTRAINDICATED so VT ablation

Question 21

Transient LOC differentials

Answer 21

1. Syncope
2. Epileptic seizure
3. Psychogenic
4. Rare

Question 22

absent prodrome suggests

Answer 22

Cardiac cause of syncope

Question 23

what type of syncope: tongue biting, tonic clonic movements, head posturing, confusion after LOC

Answer 23

Epilepsy

Question 24

What type of syncope: prodrome (sweat, nausea, light-headedness)
Situational: prolonged standing/sitting

Answer 24

Vasovagal

Question 25

Orthostatic syncope

Answer 25

postural dizziness

Question 26

Cardiac syncope

Answer 26

Structural HD Exertional syncope NO PRODROME, unpredictable Palpitations at time of syncope

Question 27

Look at QRS complexes to determine

Answer 27

regularity

Question 28

Bradycardia questions

Answer 28

1. Due to AV block-P waves not conducted to ventrciles (complete Heart block or secondary heart block) 2. Due to Sinus bradycardia: sinus node dysfunction, no AV block Leads 3 and aVF, V1: inferior leads best for looking at P waves

Question 29

Irregular P waves, outnumber QRS complexes

Answer 29

AV dissociation | 3rd degree or complete HB

Question 30

Complete HB

Answer 30

1. P waves must outnumber QRS complexes 2. Underlying rhythm regular: because it is an escape rhythm (ventricular if complexes are wide and regular) 3. No assoc between P waves and QRS complexes

Question 31

2 mechanisms of bradycardia

Answer 31

``` 1. Sinus node problem: sinus bradycardia sinus arrest tachy-brady syndrome sino-atrial exit block: absent p waves in set timing ``` 2. Impulse conduction problem: AV node or HPS problem 1st, 2nd, 3rd degree heart block

Question 32

Which degree Heart Block? | P waves outnumber QRS complexes

Answer 32

2nd/3rd degree

Question 33

Causes of sinus node dysfunction: intrinsic

Answer 33

Degen of sinus node elderly syncope, intermittent dizziness symptomatic: sick sinus syndrome

Question 34

Causes of sinus node dysfunction: extrinsic

Answer 34

Hyper: K, carbia, vagotonia Hypo: temp, thyroid, hypoxia Head injury Drugs (beta-blockers, calcium blockers, digoxin)

Question 35

Causes of Heart Block

Answer 35

DID I Count All Hairy Cats D: degen (most common) I: Inf STEMI D: drugs (digoxin) I: infiltrative (sarcoid, amyloidosis-inflammation of sinus node and purkinje system) Count: CT disorders-anyklysing spondy, SLE All: Aortic root abscess Hairy: hyperthyroid Cats: congenital

Question 36

Where is the HB: 1st/2nd degree (Type 1 Mobitz and 2:1 AV block

Answer 36

AV node level usually but also HIS PURKINJE level

Question 37

Type 2 : Type 2 Mobitz 3rd degree

Answer 37

usually at His-purkinje but 3rd degree can be at AV node level

Question 38

Cause of disease in AV node that causes heart block

Answer 38

Digoxin toxicity | QRS narrow if HP system intact

Question 39

Clinical features Complete HB

Answer 39

``` intermittent dizziness Syncope Bradycardia: 30-40 bpm, regular Variable S1 HIGH systolic BP NBBBBBBB Cannon a waves: due to AV dissociation, atrial contraction against closed Tricuspid valve ```