arrythmia Flashcards
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 )
what is the treatment of premature ventricular contraction PVC?
usually no need to for treatment
BB if persistent symptoms
treatment of the underlying cause if present
describe the ECG of ventricular tachycardia?
sustained v tach more than 30 seconds
WIDE qrs higher than 0,12 seconds
rate : atrial rate normal
RHYTHM :
onset of tachycardia : abrupt
regular HR 160-240 bpm
P waves : hidden in QRS ( AV DISSOCIATION )
P:QRS : blocked by AV node
what are the causes v tachy?
Ischemic heart disease
myocarditis
cardiomyopathy
what are the clinical features of V tach?
palpitation
hypotension
heart failure
myocardial ischemia
sudden death
frequent cannon waves on JVP jugular venous pulse due to AV dissociation
what are the treatments of V tach?
complicated with hypotension and HF and IHD —> DC
if patient is stable : lidocaine/ amiodarone
preventing attacks : intra ventricular cardioverter defibrillator
describe polymorphic V tach?
aka torsade de pointe
Rate : atrial rate normal obscured
rhythm : onset of tachycardia is absrupt FATAL
irregularly regular
P waves : hidden with QRS complexes
what is the treatment of polymorphic V tach?
unsynchronized defibrillation shock
magnesium —> stops prolonged QT
describe ventricular fibrillation ECG?
Rate : chaotic ,uncountable
Rhythm : Onset is abrupt, irregular , fatal
P waves: absent
QRS : no organized QRS complexes
what are the treatment for v fib?
immediate unsynchronized defibrillation shock
what are the shockable rhythms?
ve tach- –> monomorphic , Pulseless –> synchronized
Polymorphic V tach ( torsade de pointe ) –> unsynchronized
V fib —> unyschronized
what are the un shockable rhythms?
pulseless electric activity
asystole
describe ECG of pulseless electrical activity PEA
rate : variable- depends on baseline rhythm
Rhythm : not single rhythm
Organized Rhythm but no pulse
what is the treatment of Pulseless electrical activity PEA?
CPR : cardiopulmonary resuscitation
epinephrine during CPR , NO DC cuz no electrical problems
identify the cause :
5 Hs : hypovolemia, hypoxia, hydrogen ion ( Acidosis ), hypo/hyperkalemia , hypothermia
5 Ts: tension pneumothorax, tamponade , toxin, thrombosis ( pulmonary ), thrombosis ( coronary )
describe ECG of asystole?
Rate : absent
rhythm : none ( flatline )
P waves : absent
QRS : absent
P/QRS : not applicable
what is the treatment for ASYSTOLE?
CPR, epinephrine,
no dc cuz nothing to restart
5 HS, 5 TS
what are the types of transvenous pacemakers?
Single atrial —> rare
dual chamber : in atrium and ventricle –> commonest
Single ventricular
what are the cells affected in sick sinus syndrome?
Pacemaker cells P cells —> if affected no generation of pulse
Transitional cells T CELLS —> if affected the signal wont exit the SA node –> exit block
