Arrhythmias - pathophysiology, presentation + investigation Flashcards
which arrhythmia has the highest burden on the health service?
AF
What is supraventricular ectopy
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
presentation of patient with a heart arrhythmia? (6)
- asymptomatic
- palpitations
- SOB
- chest pain
- fatigue embolism
ECG investigation for arrhythmias
12 lead 24 hour recording
other than an ECG which 2 other investigations are undergone to look for evidence of arrhythmias
blood tests - thyroid function echocardiogram
therapeutic options to control heart rate
- Digoxin
- beta blocker
- ca2+ blockers plus warfarin (or aspirin if low risk)
therapeutic options to control heart rhythm
class Ic/III drugs +/- Direct Current cardioversion
what electrical approaches are there to correct arrhythmias
pace and ablation of AV node substrate modification e.g pulmonary vein ostial ablation
what is supraventricular tachycardia?
abnormally fast heart rhythm arising from improper electrical activity in the upper part of the heart
what are the 4 main types of supraventricular tachycardia?
AF paroxysmal SVT atrial flutter wolff parkinson-white syndrome
what is the most common type of paroxysmal SVT?
AV-nodal re-entrant tachycardia
AV-nodal re-entrant tachycardia:- symptoms, prognosis, treatment?
symptoms:- palpitations, dyspnoea, dizziness prognosis is good no treatment
What is radiofrequency ablation? (RFA)
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
what is AV re-entrant tachycardia due to?
accessory pathway
ventricular tachycardia:- signs/symptoms, cause, investigations?
palpitations, chest pain, SOB, dizziness, syncope usually caused by structural heart disease investigations:- bloods, echo, angio
What is torsades de pointes
specific form of polymorphic ventricular tachycardia in patients with a long QT interval occurs due to complete heart block/ AF
long QT syndrome
congenital or acquired may cause Torsades de pointes management: drugs, pacing or implantable cardiac defibrillator
what do first and third degree block mean?
1st = slowed conduction 3rd = complete block
indications for implantable cardiac defibrillator?
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
a patient would not be referred to get a ICD with what conditions/problems?
acute myocardial ischaemia electrolyte imblance drug toxicity
what is an ICD?
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
indications for permanent pacemaker?
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)
indications for temporary pacemaker?
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
what is left bundle branch block/ right bundle branch block? what happens to the QRS complex in LBBB/RBBB?
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
What are the 2 types of 2nd degree AV block?
type 1 - mobitz I/ wenckebach type 2 - morbitz II/ Hay
what is wolff parkinson-white syndrome?
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
What is sustained ventricular tachycardia
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
What is cardiac ablation
a procedure to scar or destroy tissue in your heart that’s allowing incorrect electrical signals to cause an abnormal heart rhythm
