ECG Flashcards
Combien de mm entre les lignes du papier et combien de temps cela représente?
-1 mm entre chaque petite ligne;
-5 mm entre les lignes épaisses;
Sur l’axe des x:
-Chaque boîte de 1 mm = 40 ms (0,04s);
-5 petites boîtes = 200 ms (0,2 s).
Sur l’axe des y:
-Chaque boîte de 1 mm = 0,1 mV;
-10 boîtes de 1 mm = 1 mV.
Durées normales des ondes et des segments:
-P: <= 120 ms (0,12 s);
-Intervalle PR: 120-200 ms (0,12-0,20 s);
-QRS: < 100 ms (0,10 s) (2,5 petites boîtes);
-Intervalle QT: < 440 ms (0,44 s).
Fréquences cardiaques à l’ECG:
-300
-150
-100
-75
-60
-50
Chaque petite boîte représente environ 3 bpm.
Qu’est-ce qu’un « SA nodal reentrant tachycardia »?
Abnormal current that spins rapidly around in the area of the SA node, resulting in fast HR.
-P wave appears normal since the depolarizations come from the SA node;
-Sudden onset and sudden cessation.
What is a sinus pause
A delay before the appearance of a P wave;
May be caused by failure of the SA node to depolarize or SA « block » which does not permit the depolarization to escape from the SA node.
What is a premature atrial complex?
Early (premature) beat, arising from somewhere above the ventricules other than the SA node (ex: in the atria or the AV junction).
Starts in an ectopic focus in the atria or AV junction. Appearance of the P wave will differ from the sinus P waves and will take a different amount of time to travel through the atria (PR interval will differ).
What is atrial bigeminy/trigeminy/quadrageminy?
Situation wherein every second/3rd/4th beat is a premature atrial complex.
What is atrioventricular reetrant tachycardia?
Abnormal current that spins rapidly around in the area of the AV node. The P waves are usually not seen or are negative and follow the QRS complex.
Quel est le rythme intrinsèque d’un foyer jonctionnel?
40-60 bpm
Quelle est la particularité du « Wandering Atrial Pacemaker and Multifocal Atrial Tachycardia »?
The P waves differ in appearence.
A commonly accepted critereon is the presence of 3 or more different P wave morphologies.
What is called the occurence of two/three premature ventricular complexes?
Ventricular couplet.
What is a string of three or more ventricular couplets called?
V-Tach
Différence entre TVNS et TVS?
-TVNS: Séquences de TV durant moins de 30 secondes;
-TVS: Séquences de TV durant plus de 30 secondes.
Que sont les torsades de pointe?
Subclass of polymorphic V-Tach in which the polarity of the QRS complexes repetitively shifts.
The cause may be reversible (ex: electrolyte abnormalities and certain medication effects).
Dans quel cas est-ce qu’une ESV est particulièrement dangereuse?
When a premature ventricular complex falls on the T wave of the preceding beat, it is much more likely to lead to a serious arythmia, such as V-Tach or V-Fib.
Called « R-on-T PVCs ».
What is a ventricular escape rythm?
Usually seen in situations when higher pacemakers (SA node, AV node) have failed to depolarize the ventricles.
Qu’est-ce qu’un bloc AV de 1er degré?
Delay in the conduction of depolarization from the atria to the ventricles. PR intervals are consistently long (>= 200 ms), but all of the depolarizations reach the ventricles.
Que sont les blocs AV de 2e degrés?
Some P waves are followed by a QRS complex, but some are not. Two major types exist: Mobitz type I (aka Wenckebach) and Mobitz type II.
Mobitz type I: progressive lengthening of the PR interval, culminating in a P wave that does not conduct down to the ventricles and therefore is not followed by a QRS complex.
-The missing QRS causes a break in the rhythm that leads to a characteristic appearence of groupes of P-QRS-Ts with spaces in between.
Mobitz type II: multiple P waves per QRS complex. It may occur occasionnally or be persistant for long periods of time. Many types depending of the number of P waves apprearing before a QRS is conducted (ex: 2:1, 3:1, 4:1, etc.).
What is AV dissociation?
The atria and ventricles are functionning independently (like a 3rd degree block), but the ventricle rate is faster than the atrial rate.
-Benign type of AV dissociation often occurs when the supraventricular (usually sinus) rate has slowed and a lower pacemaker (junctional or idioventricular) begins to pace the ventricles;
-Condition is typically transicent (when the atrial rate increases, the ventricles are captured).
Dérivations des membres et précordiales:
Dérivations des membres: I, II , III, aVF, aVR, aVL.
Dérivations précordiales: V1, V2, V3, V4, V5, V6.
À quels endroits se retrouvent les dérivations I, II et III + leurs pôles?
I: LA (+ - ) –> RA (-)
II: LL (+) –> RA (-).
III: LL (+) –> LA (+ -).
Inferior leads:
II, III, aVF
Septal leads:
V1, V2
Lateral leads:
I, aVL, V5, V6
