arrhythmia 1

Question 1

what abnormal anatomy can cause arrhythmias

Answer 1

LV hypertrophy

accessory pathways

congenital HD

Question 2

what ANS can cause arrhythmias

Answer 2

sympathetic stimulation - stress, exercise, hyperthyroidism

inc vagal tone causing bradycardia

Question 3

what metabolic can cause arrhythmias

Answer 3

hypoxia - chronic pulmonary disease and PE

ischemic myocardium - acute MI and angina

electrolyte imbalances

Question 4

what else can cause arrhythmias

Answer 4

inflammation - myocarditis

Question 5

what is an ectopic beat

Answer 5

beat or rhythm that originate in places other than the SAN

Question 6

abnormal automaticity mechanism

Answer 6

SAN normally has overdrive suppression

in ischaemia, hypokalaemia or fibre stretch the automaticity of latent pacemakers may be inc and they can cause arrhythmias by escaping from SAN dominance

Question 7

triggered automaticity mechanism

Answer 7

EAD occur in the purkinje fibres, induced by prolonged AP duration and inc inward current

DAD occur after repolarisation and are induced by inc Ca conc eg by catecholamines which inc Ca conc and HF which impairs Ca regulation

Question 8

what is an example of an anatomic reentrant circuit

Answer 8

bundle of Kent - WPW

causes tachycardia as the bundle of Kent conducts faster

also structural abnormalities and scar from MI

Question 9

what does inc phase 4 slope do

Answer 9

inc in HR and ectopics

• hyperthermia
• hypoxia
• hypercapnia
• cardiac dilation
• hypokalaemia

Question 10

what does dec in phase 4 slope do

Answer 10

dec in HR and heart bock

• hyperkalaemia
• hypothermia

Question 11

investigations

Answer 11

ECG

CXR

ECHO

stress or 24 hours ECG

Question 12

what does exercise ECG assess for

Answer 12

ischaemia or exercise induced arrhythmia

Question 13

what does 24hr ECG assess for

Answer 13

paroxysmal arrhythmia and to link symptoms to underlying heart rhythm

Question 14

what does ECHO do

Answer 14

assess for structural heart disease

Question 15

what are the symptoms of atrial ectopic beats

Answer 15

asymptomatic or palpitations

Question 16

what is the treatment of atrial ectopic beats

Answer 16

none

avoid stimulants

Question 17

SVT managent acute

Answer 17

inc vagal tone - vagotonic manoeuvres

slow AVN conductance - adenosine and verapamil

Question 18

SVT maintenance

Answer 18

B blocker and verapamil

Question 19

causes of AVN conduction disease - heart block

Answer 19

age

acute MI

myocarditis

drugs - B blockers and Ca channel blockers

calcific aortic valve disease

amyloid disease

Question 20

what do you treat mobitz II with

Answer 20

permanent pacemaker

Question 21

what is the use of Transcutaneous pacer

Answer 21

emergency temporary use till venous access achieved

Question 22

what do most patients with VT have

Answer 22

heart disease - previous MI or coronary artery disease

Question 23

treatment for ventricular fibrillation

Answer 23

defibrillation and cardiopulmonary resuscitation

Question 24

treatment for VT

Answer 24

amiodarone or lidocaine

DC if unstable

Question 25

how to treat a life threatening VT

Answer 25

ICD and CT catheter ablation

Question 26

what are benign ventricular ectopics

Answer 26

Benign condition caused by extra-systoles and tends to have a benign course.

Question 27

what is the classical presentation of benign ventricular ectopics

Answer 27

extra beat followed by a slight pause and then the heart beat returns to normal.

structurally normal heart and 24hr tape reveals ectopic beats