ECG Flashcards
ECG: Définir les termes suivants
* Segment
* Intervalle
* Complexe
- Segment : portion spécifique de l’ECG
- Intervalle : distance, mesurée comme un temps, qui survient entre 2 événements cardiaques (intervalle de temps)
- Complexe : représente un événement électrique cardiaque (dépolarisation des oreillettes, repolarisation des oreillettes, dépolarisation des ventricules, repolarisation des ventricules, transmission de l’influx via les faisceaux de His, etc.)
ECG: Définir le terme suivant - SEGMENT
Segment : portion spécifique de l’ECG
ECG: Définir le terme suivant - INTERVALLE
- Intervalle : distance, mesurée comme un temps, qui survient entre 2 événements cardiaques (intervalle de temps)
ECG: Définir le terme suivant - COMPLEXE
- Complexe : représente un événement électrique cardiaque (dépolarisation des oreillettes, repolarisation des oreillettes, dépolarisation des ventricules, repolarisation des ventricules, transmission de l’influx via les faisceaux de His, etc.)
ECG: Définir les termes suivants
* Q wave
* R wave
* S wave
- Q wave : first negative wave that we reach after the P wave
- R wave: first positive deflection after the P wave
- S wave: first negative component after an R wave
ECG: Définir le terme suivant - Q WAVE
- Q wave : first negative wave that we reach after the P wave
ECG: Définir le terme suivant - R WAVE
- R wave: first positive deflection after the P wave
ECG: Définir le terme suivant - S WAVE
- S wave: first negative component after an R wave
ECG: Onde P - Ce que l’onde représente
Electrical depolarization of both atria
- The wave starts when the SA node fires. It also includes transmission of the impulse through the three internodal pathways, the Bachmann bundle, and the atrial myocytes themselves.
- Positives: DI, DII, DIII, aVF
- Negative : aVR
- Inverted P waves are found when the pacing or initial impulse originates at or below the AV node
ECG: Onde P - Dérivations où elle est POSITIVE vs NÉGATIVE
- Positives: DI, DII, DIII, aVF
- Negative : aVR
- Inverted P wave are found when the pacing or initial impulse originates at or below the AV node
ECG: Onde P - Ce que veut dire des onde P INVERSÉE
- Inverted P waves are found when the pacing or initial impulse originates at or below the AV node
ECG: Segment PR - Ce que le segment représente
- Occupies the time frame between the end of the P wave and the beginning of the QRS complex.
- Transmission of the electrical depolarization wave through the AV node, His bundles, bundle branches, and Purkinje system.
- It can be depressed by less than 0,8 mm under normal circumstances; anything greater than that is pathological.
- It is pathologically depressed in pericarditis, and when there is an atrial infarct (rare).
ECG: Segment PR - Dans quelles criconstances / pathos peut-il être affecté?
- It can be depressed by less than 0,8 mm under normal circumstances; anything greater than that is pathological.
- It is pathologically depressed in pericarditis, and when there is an atrial infarct (rare).
ECG: Intervalle PR - Ce qu’il représente
- Time period from the beginning of the P wave to the beginning of the QRS complex: it includes the P wave and the PR segment.
- Covers all the events from the initiation of the electrical impulse in the SA node up to the moment of ventricular depolarization.
- The atria, the AV node, bundle of His, both bundle branches and the Purkinje system are all depolarizing and conducting the impulse.
ECG: Compexe QRS - Ce qu’il représente
- Ventricular depolarization
- Two or more waves
- Q wave: can be benign, or it can be a sign of dead myocardial tissue
— Significant if it is 0,04 seconds or wider, or its height is equal to or greater than 1/3 the height of the R wave = indicates a myocardial infarction
— It if doesn’t meets either of these criteria = not a significant Q wave
ECG: Compexe QRS - Nombre de vague nécessaire
- Two or more waves
ECG: Compexe QRS - Les ondes Q peuvent signifier quoi?
Q wave: can be benign, or it can be a sign of dead myocardial tissue
* Significant if it is 0,04 seconds or wider, or its height is equal to or greater than 1/3 the height of the R wave = indicates a myocardial infarction
* It if doesn’t meets either of these criteria = not a significant Q wave
ECG: Segment ST - Ce quil représente
- From the end of the QRS complex to the beginning of the T wave.
- Electrically neutral period between ventricular depolarization and repolarization (represents the time that the myocardium is maintaining contraction in order to push the blood out of the ventricles)
- J point: point where the QRS complex ends and the ST segment begins
- Many times, a clear J point cannot be identified because of ST segment elevation.
- The ST segment is usually found along the baseline. It can vary up to 1 mm from baseline in the limb leads of normal patients, and up to 3 mm in the right precordials of some patients.
- Any ST elevation in a symptomatic patient should be considered significant and representative of myocardial injury or infarction until proven otherwise.
ECG: Segment ST - Localisation
From the end of the QRS complex to the beginning of the T wave.
ECG: J Point
- J point: point where the QRS complex ends and the ST segment begins
- Many times, a clear J point cannot be identified because of ST segment elevation.
ECG: Segment ST - Décrivez un segment ST normal
- The ST segment is usually found along the baseline. It can vary up to 1 mm from baseline in the limb leads of normal patients, and up to 3 mm in the right precordials of some patients.
- Any ST elevation in a symptomatic patient should be considered significant and representative of myocardial injury or infarction until proven otherwise.
ECG: Segment ST - Qu’est-ce qu’un segment ST anormal?
- The ST segment is usually found along the baseline. It can vary up to 1 mm from baseline in the limb leads of normal patients, and up to 3 mm in the right precordials of some patients.
- Any ST elevation in a symptomatic patient should be considered significant and representative of myocardial injury or infarction until proven otherwise.
ECG: T Wave - Qu’est-ce qu’elle représente?
- Represents ventricular repolarization
- Should begin in the same direction as the QRS complex
- A negative wave (repolarization is a negative wave) traveling away from the electrode is perceived the same as a positive wave moving toward it.
- The T wave should be asymmetrical, with the first part rising or dropping slowly and the latter part moving much faster.
- Symmetric T waves can be normal, but are usually a sign of pathology
ECG: T Wave - Qu’est-ce qu’une onde T normale?
- A negative wave (repolarization is a negative wave) traveling away from the electrode is perceived the same as a positive wave moving toward it.
- The T wave should be asymmetrical, with the first part rising or dropping slowly and the latter part moving much faster.
- Symmetric T waves can be normal, but are usually a sign of pathology
ECG: T Wave - Qu’est-ce qu’une onde T Anormale?
- The T wave should be asymmetrical, with the first part rising or dropping slowly and the latter part moving much faster.
- Symmetric T waves can be normal, but are usually a sign of pathology
ECG: Intervalle QT - Ce que c’est, ce qu’il représente
- Section of the ECG complex encompassing the QRS complexe, the ST segment, and the T waves – from the beginning of the Q to the end of the T wave
- Represents all of the events of ventricular systole, from the beginning of ventricular depolarization to the end of the repolarization cycle.
- QTc: QT corrected interval (corrected for the heart rate)
ECG: Qu’est-ce que le QTc?
- QTc: intervalle QT corrected interval (corrected for the heart rate)
ECG: U wave - Ce que c’est, ce que ça représente
- Small, flat wave sometimes seen after the T wave and before the next P wave.
- Nobody knows for sure what it really represents.
- Deflects in the same direction as the T wave
ECG: U wave - Décrire son apparence
Deflects in the same direction as the T wave
ECG: R-R interval - Définir / décrire, utilité, normale
- Distance between identical points of two consecutive QRS complexes
- Measuring this often to evaluate the rhythm.
- Regular rhythms are those that have consistent R-R intervals.
ECG: P-P interval - Décrire / définir, utilité
- Distance between two identical points on one P wave and the next
- Very useful in evaluating the patient for rhythm abnormalities
ECG: Qu’est-ce qu’un rythme sinusal normal?
- The SA node is always the primary pacemaker for the heart in normal sinus rhythm.
- Since there is only one pacemaker, the P waves need to be identical. In addition, since the distance and route taken to reach the AV node are the same, the PR intervals have to be both normal and consistent.
- ECG: the P wave must always be upright in leads II, III and aVF during NSR.
- If the P waves are negative in leads II, III and aVF, the rythym cannot be NSR and there has to be an ectopic pacemaker