Arrhythmias - pathophysiology, presentation + investigation

Question 1

which arrhythmia has the highest burden on the health service?

Answer 1

AF

Question 2

What is supraventricular ectopy

Answer 2

a premature contraction of the ventricles an be caused by hypertensive heart disease or other structural heart diseases -resulting in LA enlargement and increased wall stress - could lead to AF

Question 3

presentation of patient with a heart arrhythmia? (6)

Answer 3

• asymptomatic
• palpitations
• SOB
• chest pain
• fatigue embolism

Question 4

ECG investigation for arrhythmias

Answer 4

12 lead 24 hour recording

Question 5

other than an ECG which 2 other investigations are undergone to look for evidence of arrhythmias

Answer 5

blood tests - thyroid function echocardiogram

Question 6

therapeutic options to control heart rate

Answer 6

• Digoxin
• beta blocker
• ca2+ blockers plus warfarin (or aspirin if low risk)

Question 7

therapeutic options to control heart rhythm

Answer 7

class Ic/III drugs +/- Direct Current cardioversion

Question 8

what electrical approaches are there to correct arrhythmias

Answer 8

pace and ablation of AV node substrate modification e.g pulmonary vein ostial ablation

Question 9

what is supraventricular tachycardia?

Answer 9

abnormally fast heart rhythm arising from improper electrical activity in the upper part of the heart

Question 10

what are the 4 main types of supraventricular tachycardia?

Answer 10

AF paroxysmal SVT atrial flutter wolff parkinson-white syndrome

Question 11

what is the most common type of paroxysmal SVT?

Answer 11

AV-nodal re-entrant tachycardia

Question 12

AV-nodal re-entrant tachycardia:- symptoms, prognosis, treatment?

Answer 12

symptoms:- palpitations, dyspnoea, dizziness prognosis is good no treatment

Question 13

What is radiofrequency ablation? (RFA)

Answer 13

reduces pain in the heart An electrical current is used to heat up a small area of nerve tissue, thereby decreasing pain signals from that specific area

Question 14

what is AV re-entrant tachycardia due to?

Answer 14

accessory pathway

Question 15

ventricular tachycardia:- signs/symptoms, cause, investigations?

Answer 15

palpitations, chest pain, SOB, dizziness, syncope usually caused by structural heart disease investigations:- bloods, echo, angio

Question 16

What is torsades de pointes

Answer 16

specific form of polymorphic ventricular tachycardia in patients with a long QT interval occurs due to complete heart block/ AF

Question 17

long QT syndrome

Answer 17

congenital or acquired may cause Torsades de pointes management: drugs, pacing or implantable cardiac defibrillator

Question 18

what do first and third degree block mean?

Answer 18

1st = slowed conduction 3rd = complete block

Question 19

indications for implantable cardiac defibrillator?

Answer 19

patient must be in life threatening condition cardiac arrest due to VF/VT not due to transient or reversible cause e.g early phase of acute MI sustained VT causing syncope or significant compromise or sustained VT with poor LV function

Question 20

a patient would not be referred to get a ICD with what conditions/problems?

Answer 20

acute myocardial ischaemia electrolyte imblance drug toxicity

Question 21

what is an ICD?

Answer 21

an implantable cardiac defibrillator which sends electrical impulses to regulate abnormal heart rhythms most new ICDs can act as pacemakers and defibs good at preventing sudden death

Question 22

indications for permanent pacemaker?

Answer 22

symptomatic or profound 2nd/3rd degree AV block, particularly when cause is unlikely to disappear probably mobitz type II 2nd/3rd degree AV block even if asymptomatic Given after AV node ablation - pain reduction alternating Left bundle branch block and RBBB sinus node disease associated with symptoms carotid sinus hypersensitivity/malignant vasovagal syncope (over-reactive vagus nerve to certain triggers ie sight of blood)

Question 23

indications for temporary pacemaker?

Answer 23

if heart beat is temporarily out of rhythm ie intermittent or sustained symptomatic bradycardia, particularly syncope then temporary pacemaker can be used it is prophylactic - option when patient is at high risk of developing sever bradycardia e/g 2nd/3rd degree AV block, post-anterior MI or even when asymptomatic

Question 24

what is left bundle branch block/ right bundle branch block? what happens to the QRS complex in LBBB/RBBB?

Answer 24

an anatomical or functional block in the left or right bundle branches causes LBBB or RBBB the ventricle whose bundle branch is defect will be depolarised from impulses spreading from the opposite ventricle causes a broad QRS complex

Question 25

What are the 2 types of 2nd degree AV block?

Answer 25

type 1 - mobitz I/ wenckebach type 2 - morbitz II/ Hay

Question 26

what is wolff parkinson-white syndrome?

Answer 26

a condition in which there is an extra electrical pathway in the heart. The condition can lead to periods of rapid heart rate (tachycardia). WPW syndrome is one of the most common causes of fast heart rate problems in infants and children

Question 27

What is sustained ventricular tachycardia

Answer 27

Tachycardia of the ventricles which if sustained is life threatening

signs: hypotension, cardiac arrest, pulse rate 120/220 BPM, AV dissociation

symptoms - syncope, pre-syncope

investigations: ECG - rapid V rhythm, broad QRS complexes, visible P waves march through tachycardia

Management - if haemodynamically compromised (hypotensive/pulm oedema) emergency DC cardioconversion may be required (defib)

if more stable then IV class 1 or amiadarone may be used

Question 28

What is cardiac ablation

Answer 28

a procedure to scar or destroy tissue in your heart that’s allowing incorrect electrical signals to cause an abnormal heart rhythm