Transcript Electrophysiologic backround for ECG evaluation

Electrophysiologic backround for ECG
evaluation
Prof. J. Hanáček, MD, PhD
Physiologic ECG curve – its parts
Standard bipolar and augmented unipolar leads
ECG record from standard limb leads
Precordial leads
Scheme of horizontal cut of chest with projection of chest
leads and direction of atrial and ventricular depolarisation
Calculation of heart rate from ECG curve
Evaluation of ECG curve
1) Basic information on the patient –age gender, reason for
recording ECG, preliminary Dg
2) Technical parameters of ECG curve – speed of recording,
sensitivity of recording device
3) Date and time of ECG recording
Calculation of heart rate
Electric axis of a heart
Factors which influence electric axis of hart
How to create electric axis of a heart – lead I
How to create electric axis of a heart – lead I and
aVF
Left axis deviation
Right axis deviation
Description QRS complex deflections
Heart rhythms
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Sinus rhythm
Atrial rhythm
Junctional rhythm (atrio-ventricular)
Ventricular rhythm
● Heart rhythm is not heart rate, is not regularity of heart
function
● Heart rhythm means localisation of source of
electrical impuls for activation of heart
Sinus rhythm
- heart function ic controled by sinus node activity
Characteristics of sinus rhythm:
- There should be P wave in front of QRS complex
- P wave is negativ in aVR lead and positive in aVF lead
- P wave should have normal duration and shape
Junctional rhythm
- Polarity of P wave is changed
-Localisation of P wave is also
changed
Passive ventricular depolarisation – escape beat
Simple guide for ECG evaluation
- In ECG curve is hidden a lot of important information
useful for understanding heart function under
physiologic and pathologic conditions
- To find this informations you should have appropriate
knowledge and ability to observe carefully the ECG curve
- For good result of ECG curve evaluation is necessary
to evaluate it systematically – using some type of
algorhythm
1) Characteristics of patient – age, gender, date of ECG record was done
preliminary diagnosis, other informations on patient
2) To control technical quality of ECG record, speed of ECG record,
sensuitivity of recording device (inappropriate contact of electrodes
with the skin, interference of electricity, other
3) Evaluation frequency of QRS complexes, P waves
4) Evaluation of heart rhythm
5) Evaluation of heart axis
6) Evaluation of separate waves, deflections, segments and intervals
7) Each abnormality should be taken into accont