arrhythmias Flashcards
how to work out heart rate on ECG
count number of large squares between QRS complexes and divide 300 by that number
what is the commonest rhythm, disturbance
atrial fibrillation
atrial fibrillation pulse should be
irregularly irregular
presentation of atrial fibrillation
palpitations, dyspnoea, chest pain, fatigue, embolism
investigations of atrial fibrillation
document arrhythmia on ECG- 12 lead, 24 hour recording, event recorder, blood tests esp thyroid function, echocardiogram
treatment of AF
rate control vs rhythm control. drugs, electrical approaches. consider anticoagulation eg NOACs or warfarin but risk of bleeding must be less than risk of stroke
control of rate in AF
beta blockers, ca- antagonist,
electrical approaches to AF treatment
if can’t control ventricular rate and patient remains symptomatic. pacemaker, ablation of AV node, substrate modification eg pulmonary vein isolation, surgical procedures
control of rhythm in AF
digoxin versus class Ic, III drugs eg flecainide, amiodarone +/- DC cardioversion
AV nodal reentrant tachycardia
AV nodal reentrant tachycardia. causes palpitations, dyspnoea, dizziness. has good prognosis- no treatment. adenosine treatment. if keeps recurring then catheter ablation is good with high success and low recurrence
supra ventricular tachycardia
occurs above the ventricles..` AV nodal reentrant tachycardia, AV reentrant tachycardia, atrial flutter
atrial flutter
blood going around the atrium, passes between the tricuspid valve and the vena cava, rapid, lots of atrial waves, will occur even after treatment so is best to ablate the area, prevent with AA drugs or RFA of cavotriscupid isthmus
ventricular tachycardia
usually structural heart disease, palpitations, dizziness, CP, dyspnoea, syncope, do bloods echo angio etc.
ventricular tachycardia on the ECG
waves up and down not normal just straight up straight down
prevention of ventricular tachycardia
ICD, AntiArrhythmic drugs, physical exam, underlying cause
termination of ventricular tachycardia
cardiac arrest protocol, DC cardioversion or drugs
torsades de pointes
an uncommon and distinctive form of polymorphic ventricular tachycardia (VT) characterized by a gradual change in the amplitude and twisting of the QRS complexes around the isoelectric line. prolonged QT interval, which may be congenital or acquired
long QT syndrome
congenital (autosomal dominant, gene mutation identification in most) or acquired (drugs). may cause TdP, physical exam, drugs, pacing or ICD
Implantable cardioverter defibrillator ICD used when
secondary prevention. cardiac arrest due to VF/VT not due to transient or reversible cause eg early phase of acute MI, sustained VT causing syncope or significant compromise, sustained VT with poor LV function
sick sinus syndrome
sinus node fails to create an impulse
complete heart block
P wave is regular but they bear no relation to QRS complexes or ventricular activity
mobitz 1
failure of AV node to conduct. produced by progressive fatigue of the AV nodal cells,
mobitz 2
“all or nothing” phenomenon whereby the His-Purkinje cells suddenly and unexpectedly fail to conduct a supraventricular impulse.
indications for permanent pacing
symptomatic or profound 2nd or 3rd degree AV block, particularly when cause is unlikely to disappear, probably mobitz II 2nd or 3rd degree AV block even If asymptomatic, AV block associated with neuromuscular disease, after or in prep for AV node ablation, alternating RBBB/LBBB, syncope when bifascicular/ trifascicular block and no other explanation, sinus node disease associated with symptoms, carotid sinus hypersensitivity/ malignant vasovagal syncope, poor LV function with LBBB
careful history is essential for what
to distinguish the serious from the benign (benign requires no treatment just reassurance)
what is essential for diagnosing arrhythmia
12 lead ECG along with symptom rhythm correlation if necessary with ambulatory monitoring
