ELECTROCARDIOGRAPHY EMERGENCY IN PRACTICE:
Introduction:
The intent of this writing, is not to create a new manual rather not clarify whether those concepts to my students mainly emergency leave their practices and are pressed against the EKG reading.
how?
Therefore to truly learn electrocardiography should study the texts created for that purpose (as Punto Dubin heading, is a simple and very practical manual)
1 .- What do I do with an EKG in hand? Seeing
when done.
If there is bad art (baseline vibration, disconnection of an electrode, ...) should be repeated. Always follow a systematic
for interpretation.
At the head of the EKG should include the patient's name and date and time of completion and whether or not symptoms.
not hesitate to consult.
not write to the measure on the path electrocardiográfico.Ni marking pencil. The electrocardiogram generalmemte
edit the EKG in the following format:
I aVR V1 V4II aVL aVF V3 V6 V2 V5III rhythm strip (II)
EKG's role should be "run" at a speed of 25 mm / s, with a look to see when we see changes in HR that "we do not add up."
The paper is separated by "squares" smaller than 1 mm each and every 5 mm, there is a thicker line.
The distance between each line is 5 mm thick, and corresponds to 0.2 seconds (200msec), so that a second corresponds to 25 mm.ONDAS, COMPLEX, CLASS AND SEGMENT OF EKG first thing we do is "take a look "them, which, while not have to llevarnosmucho time we begin to focus on the pathological that could have EKG before us.
2.-There
P wave? Atrial contraction.
3.-There
QRS complex? Ventricular contraction.
4.-There
T wave? Ventricular repolarization.
PR interval (from the beginning of the p to the beginning of the QRS). Should be 0.2 sec: first degree AV block (see if you take drugs that lower conducciónpor NAV). If 0.12 sg: QRSancho. Check
is sinus rhythm (or SV): Bundle branch block.
Go to V1.
If QS: BRI.
If R: BRD. Important
see previous EKG (pre-BR) and BR assess frequency-dependent aberrancy (Sonbre displayed at high frequencies, and frequencies disappear "low").
If tachycardia or bradycardia and QRS width, see section bradicardias.El QRS tachycardia and in which we look at is the QRS of the derivation in which more ancho.QT: Since the beginning of QRS to the end of the T (U?). Should be 500 msec, risk of torsade de pointes, especially if bradicardia.El QT in which we look at is the QT of the derivation in which the longest.
WHERE DO I START?
1. heart rate (ventricular rate): Go to strip ritmo.Contar the number of QRS complexes of all rhythm strip and multiply by FC seis.Si regular, you can see the distance between two adjacent complexes, if 5 mm: FC300 bpm, if 10 mm: HR 150 bpm, if 15 mm: HR 100 bpm, if 20 mm FC 75 bpm if 25mm: FC 60 lpm, if 30 mm FC 50 mm.Si 100 bpm tachycardia. In this case the important thing is objectively the case detaquicardia QRS QRS wide or narrow. In case of narrow QRS in mayoríade try cases supraventricular tachycardia (SVT). If we QRS width, this should get very alert, and in these first we must ask Councilof guards immediately, as may be due to ventricular tachycardia (VT). Tenemosque look if it is regular or irregular tachycardia (irregular is extremely rare if it is TV, except AF with WPW). The first thing is to know if the patient has had previous BR or not (EKG or previous reports). There are some criteria for the identification of wide QRS tachycardia, you can see in texts EKG. Anyway
with wide QRS tachycardia, we must discard urgent question of TV, yaque they can degenerate into ventricular fibrillation (VF) and death.
2. Rate:
ritmo.Observar Go to strip if the QRS are separated by the same distance from each other. Nap at the same distance is a regular ventricular rate or rhythm. If not Loest is said to be irregular or wave arrítmico.Buscar "p" (? Atrial contraction). Where better is identified ENV1 and II. Study its relation to the QRS (if regular distance atodos precedes the QRS, usually RS). The sinus
p is positive in inferior (II, III and aVF) and negative p aVR.Si not see any leads: AVB 2 or 3rd grade.
Observe what is the pacemaker of the heart: sinus node, focus (AF, Flutter, Atrial Tachycardia: TA), AV node (narrow QRS, not observaactividad handset before each QRS, can be seen waves "p" after QRS decade: p backward, which are negative in bottom). Focus
ventricular (QRS width can be observed independent atrial activity laventricular: AV dissociation or retrograde p times).
3. Shaft:
In the emergency setting has little practical value, especially in our primerasguardias. Should be calculated both in RS, such as tachycardia, because the location of ejepuede help us identify the origin of certain tachycardias (VT). To calcularlode is approx., We should only look at I and aVF. If the QRS is positive (R> S or Q) R aVF yen, it said that the axis is normal (between 0 º and 90 º). If R is positive, but negative enaVF, the axis is izdo (between - 90 º and 0 º). If R is negative (no matter how seaen aVF), the shaft will dcho (> 90 °).
4. Hypertrophy:
is important in the overall context of the EKG as well as in emergency management administration drugs, as certain drugs, especially antiarrhythmic agents, should not be administered to patients with structural heart disease, and monitoring electrocardiographic signs suggestive of hypertrophy is a relatively reliable indicator of structural heart disease.
We look at V2 and V5. If the sum of voltages V2 S plus R in V5 is 35mm, we can say that there is LV hypertrophy. Anyway, looking at high R izdas precordial (V4-V6), and / or deep enprecordiales dchas S (V1-V3), let us also think VI.5 hypertrophy.
Alterations of repolarization:
First of all we know the relationship between the leads of the EKG and cardiac anatomy, mainly VI. V1 and V2
correspond to the interventricular septum.
V2, V3 yV4 correspond to the front.
V5 and V6 lateral.
I and aVL high lateral.
II, III and aVF inferior.
We must look to the orientation of the T (positive, flat or negative) and the ST segment changes.
We should try to know if the electrocardiographic alteration is acute or chronic corresponds to something.
SCA (ACUTE CORONARY SYNDROME :
In cases of suspected acute coronary Sd, it is important to note that to observe "changes in the EKG," we have more of a patient's EKG, EKG although the first seems "normal." (Example: If a patient arrives with chest pain and EKG bland, we administer NTG SL and gives pain, we must repeat the EKG, that seemed quite normal for the first EKG). ST
Promotions: To be meaningful must be 1mm.
is important to note the location (consistent with anatomical areas), since, for example, simultaneous
ST elevation in V1 and aVL is meaningless because it does not correspond to the same anatomical area; whereas if the lift is in V5 and V6, targets an caralateral process.
also important to note whether the ST elevation is localized or generalized (in leads for various anatomic areas).
The morphology of the ST elevation is another aspect to consider. A elevaciónconvexa up is suggestive of disease, while if it is concave upward (hanging) is more suggestive of pericardial process or early repolarization (low probability of ischemic).
Of all the ways it is important to know that the morphology can "fool" as we sometimes see low elevations suggestive of ischemic sufriendoeventos in patients with coronary disease. ST
Drops: Also remember the anatomical areas. Importantly, LV overload can lead ST depression in lateral and valvular disease (stress). Q Waves
: Depending on the size of the Q wave, it will be significant or not, is usually a Q wave decirque significant when more than 1 mm wide and at least 1 / 3 "high" that the RS of the same complex. In the emergency setting, the observation of Q waves do not mean an acute phenomenon, although us towards the possibility of an ischemic patient setrate (Former AMI).
Also remember that Q waves are not only in ischemic patients, but also seen in ventricular overloads and other cardiomyopathy (HCM).
negative T waves: They are a warning sign on, as can be seen encardiopatía ischemic, reperfused myocardial infarction (open cup), unstable angina and pulmonary embolism.
To discriminate if indeed they are of acute nature, we observe "the evolution in time", since a patient with positive T and chest pain, after removing the pain, negative the T, is very suggestive of being ischemic (pseudonormalization T wave), while if these negative T waves is a casual event, and already presented in previous EKG, may be "something" chronic, which is less a matter of urgency.
However, the observation of negative T we must rule out ischemic heart disease (most often) and PET.
In patients with implanted pacemakers, the observation of negative T waves in the fasesde no ventricular stimulation, may have no pathological significance, as the most frequent question last eléctrica.Como memory "recommendation" in this section changes repolarization, it would be good to convey, we can not remain calm with a single EKG. This means that if we suspect an ischemic event (through clinical risk factors, previous episodes, ...), we should never dismiss because the ECG or EKG `s are normal, as is ischemic heart disease patients with pacemakers traicionera.En implemented, it is very difficult to assess changes in repolarization, as well as in patients with LBBB base.
As a final summary, here is a table of the aspects we look at an EKG, for this or any other order.
1. Frequently (rhythm strip).
2. Rhythm (rhythm strip).
3. Watching the PR, QRS width and morphology, and QT.
4. Axis (in I and aVF).
5. Hipretrofias (in V2 and V5).
6. Alterations of repolarization (T wave, Q wave, ST).
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