arrythmia Flashcards
(41 cards)
what is the anatomy of the conduction system ?
SA node
internodal pathway
AV node
Common bundle of his
left bundle branch
right bundle branch
purkinje system
describe the normal sinus rhythm?
60-100
regular rhythm
P wave present
P —> QRS 1:1 every p wave followed by QRS
what are the causes of cardiac arrhythmias ?
ENHACED AUTOMATICITY:
- Enhanced normal automaticity —> sinus tachycardia
-abnormal automaticity Ischemic
TRIGGERED ACTIVITY:
Early after depolarization EAD –> hypoxia, hypokalemia, acidosis, ion channel defects
delayed after depolarization DAD —> digoxin toxicity
RE ENTRY :
macro LARGE reentry commonest as in scar —> atrial flutter
micro SMALL reentry –> Ischemic Heart D induced arrhythmias , brugada syndrome
how do you approach and analysis ECG ?
Rate —> normal/tachy/brady
rhythm —> regular/irregular
QRS width —> normal wide
P wave —> is present or nah 1:1
what are the supraventricular arrhythmia?
Sinus tachy
atrial premature contraction ( APC ):
premature atrial beat
atrial premature beat
premature atrial complex
atrial fibrillation
atrial flutter
Reentry tachy
describe sinus tachycardia ?
rate is more than 100/min
regular rhythm
P waves are present
p —> QRS 1:1 conduction
what are the causes of sinus tachycardia ?
anemia
fever
thyrotoxicosis
heat failure
pulmonary embolism
shock
js treat the cause in case of pathological
physiological :
exercise
Fear
anger
Emotions
describe the premature atrial contraction PAC?
rate : sinus rate
rhythm : occasionally irregular - interrupted by the premature atrial contraction
-incomplete compensatory pause –> after the contraction LAG in the one behind to understand what happened
P waves : usually different morphology ( a wave for premature contraction before P wave )
P:QRS : usually 1:1 with the premature atrial contraction
what is the treatment for PREMATURE ATRIAL PAC?
treat underlying cause if present
usually occurs on normal hearts so no treatment needed
what are the different accessory pathways in SVT?
AV reentry tachycardia AVRT —> accessory pathway between the atrium and ventricle that is not AV node —> creating circuit between atrium and ventricle
AV nodal reentry tachycardia AVNRT ( COMMONEST ) —-> the AV node has an reentrant circuit near it leading to –> one signal keeps stimulating it over and over
Atrial tachycardia —> ectopic atrial focus
what is AVNRT usually associated with ?
Premature atrial contraction
also sometimes occur on normal hearts and sometimes due to disease or drug/substances
describe the ecg AV nodal reentry tachycardia?
rate : atrial rate 150-250 bpm
Rhythm : Abrupt onset and offset of tachycardia
Regular rhythm
P waves : hidden with QRS and sometimes retrograde
P:QRS –> regular conduction 1:1
what is the treatment for AVNRT?
Hemodynamically stable :
- Vagus maneuvers
- Adenosine 1st , Verapamil 2nd , BB or amiodarone 3rd line
IF hemodynamically unstable : DC
IF recurrent : Radiofrequency ablation of AV nodal slow pathway
describe ecg atrial flutter ?
rate : Atrial rate 250-400 bpm
Rhythm :
atrial rhythm is regular
Ventricular rhythm irregular or regular
irregular when 2:1 av block
P waves : Absent —> replaced by flutter waves , SAWTOOTH APPERANCE ( F WAVES )
F wave : QRS : conduction is regular unless AV block 2:1
what is the treatment for atrial flutter?
same as atrial fibrillation
what are the causes of atrial fibrillation ?
idiopathic
hypertension
myocardial ischemia
mitral stenosis
myocarditis
constrictive pericarditis
Cardiomyopathy
thyrotoxicosis
Drugs – > digoxin
describe the ECG of atrial fibrillation ?
RATE:
Atrial rate cannot be measured —> 400-600
Ventricle rate : variable ( irregular or regular )
RHYTHM :
Irregularly irregular
P waves : ABSENT –> FIBRILLATION WAVE ( F WAVE )
F : QRS : irregular
what is the treatment of atrial fibrillation ?
slow ventricle rate by rate control
anticoagulation
restore sinus rhythm
treat underlying cause
what are the treatment triad for atrial fib and atrial flutter ?
Anticoagulation : to protect from stroke
Ventricular rate control :
- BB, CCB, Digoxin ( in heart failure )
-AV node ablation + permanent pacemaker
Conversion to sinus rhythm IF STRUCTURE IS STILL NORMAL :
- Medically : flecainide , amiodarone, propafenone, quinidine
DC : if hemodynamically unstable and as an elective after 3 weeks of anticoagulation
what is the timing where you use DC?
synchronized with :
Peak of R wave
Nadir of S wave ( Deepest point
what are the ventricular arrhythmias?
premature ventricular contraction PVC :
ventricular premature contraction VPC
premature ventricular beat PVB
premature ventricular complex
Ventricular tachycardia
ventricular fibrillation
pulseless electrical activity –> non shockable
asystole –> non shockable
what are the cardiac arrest rhythms ?
Ventricular tachy : if pulseless
Ventricular fibrillation
pulseless electrical activity PEA
Asystole
describe the premature ventricular contraction PVC?
wide bizarre QRS complex larger than 0.12 seconds
originating from the ventricles
followed by a period of pause ( lag pause )
sinus node is continuous and continue to discharge normally
what are the types of premature ventricular contraction ?
unifocal isolated PVC –> one PVC , occur sporadically , no specific rhythm
Bigeminy —-> occur in a pattern , one PVC after one normal beat so , PVC normal PVC normal
MULTIFOCAL PVC : multiple ectopic foci , PVC different in sizes and origin , irregular rhythm
PVC couplet : 2 pvcs back to back
Non sustained VT/ VT run : 3 OR MORE PVC BACK TO BACK AND TERMINATE SPONTANEOUSLY ( LESS THAN 30 SECONDS )
