ECGs Flashcards
P wave?
Atrial depolarisation
PR interval?
SAN-AVN <200 msecs
QRS complex?
Ventricular depolarisation
T wave?
Ventricular repolarisation
QT interval
<460 msecs
U wave?
Repolarisation of papillary muscles
Causes of first degree heart block?
Acute MI Hypokalaemia Digoxin Beta-blocker Rheumatic fever Lyme disease SLE Myocarditis
Treatment for first degree heart block?
No specific treatment, treat cause
What is first degree heart block?
Prolonged PR interval
What is T1 second degree heart block?
Wenckebach - irregular QRS, increasing PR interval until no QRS for one cycle
Cause of second degree heart block?
Fibrosis IHD Cardiomyopathy Congenital Valvular heart disease MI Metabolic disturbances
What is T2 second degree heart block?
Regularly dropped QRS complexes e.g. every 2 or 3 beats
What is Stokes-Adams attacks?
Episode of syncope caused by slowing of ventricular rate (type II,
What is third degree heart block? ECG findings?
No relationship between atrial and ventricular contraction. Broad QRS, RR long, PR random, 30-40 bpm
New onset left bundle branch block?
MI until proven otherwise
Left bundle branch block?
WilliaM on ECG, left axis deviation, wide QRS
Right bundle branch block
MarroW, prolonged QRS, t wave inversion in lead 1 and 2
Sinus bradycardia?
rate <60, normal PR
Causes of sinus bradycardia?
Athlete Beta-blockers Calcium channel Potassium channel Digoxin Hypothyroid Hypokalaemia Hypothermia SSS MI Vasovagal
Treatment for sinus bradycardia?
ONLY IF SYMPTOMS
remove beta-blocker, oxygen, fluids, IV atropine or adrenaline, pacing
Beta-blocker overdose?
Glucagon
What MI causes bradycardia
Inferior - RCA = SAN
Inferior MI on what leads?
II, III, aVf
Lateral MI on what leads?
I, aVL, V5, V6
Anterior MI on what leads?
V1-V6
What is levs disease?
Idiopathic fibrosis of SAN - causes SSS and 3rd degree heart block
What is SSS
Sick sinus syndrome - disease of the sinoatrial node - sinus bradycardia, sudden rate changes, atrial standstill, AV escape rhythms
Cause of 3rd degree heart block?
Fibrosis, congenital, aortic stenosis, surgery, IHD
Atrial fibrillation
Irregularly irregular heart rate, re-entry circuits
AF caused by?
Mitral stenosis Mitral regurgitation PE IHD Hypomagnesia Digoxin toxicity Dilated atrial cardiomyopathy
Paroxysmal AF?
Recurrent AF that terminates spontaneously within 7 days
Persistent AF?
AF lasting longer than 7 days
Long standing persistent AF?
more than one year
Permanent AF?
refractory to cardioversion
AF symptoms?
Palpitations
Chest pain
Syncope
Pulmonary oedema
Treatment of AF? (haemodynamically unstable)
Cardioversion
Treatment of AF?
Beta blockers/calcium blockers or amiodarone if heart failure.
Must anticoagulate
Complications of AF
Stroke
MI
Heart failure
When is digoxin used?
Older patients
What is electrical alterans?
Varied QRS - pericardial effusion
Asystole?
No cardiac activity
Right atrial enlargement on ECG?
Peaked p wave - P Pulmonale
Left atrial enlargement on ECG?
bipeaked p waves - P Mitrale
Sign of previous MI?
Q waves
Medication causing long QT?
Sotalol Amiodarone Erythromycin Clarithromycin Haloperidol Chlorpromazine
What is the normal range of QRS axis?
-30 to +90
Leads V1, V2 and V3 measure which direction?
anterior/posterior forces
Leads I, aVr, aVl, V4, V5 and V6 measure which direction?
Right to left
What forces do II, III and aVf measure?
Inferiorly
Cardioversion for new-onset AF?
Flecainide or amiodarone if no structural or ischemic heart disease
Amiodarone if structural abnormality