1. ECG to continue….

2. Interval changes assessment

3. PR (PQ) interval QT interval Normally .12 s - .20 s
(that is 3 – 5 mm of horizontal distance)
Shorter (e.g.) in preexcitation syndromes
Longer (e.g.) in AV block of first degree
Dependent of the frequency
For 60 beats / s is around 0.45 s
QT interval

4. Preexcitation syndromes
Accessory signal pathway
Orientation of QRS complex vector depends on the direction of propagation of the signal
Sy Wolff-Parkinson-White
has “delta” wave
Sy Lown-Ganong-Levin (without “delta” wave)
Risk of supraventricular paroxysmal tachycardia

5. type A type B

6. Reentry tachyarrythmias
Reentry in Wolff-Parkinson-White’s Syndrome
Accessory pathway
Ectopic atrial extrasystole
tachycardia
wave
Short PR

7. AV block 1-st degree: Long PR inteval 2-nd degree
type one
type two
3-rd degree: No connection between atria and ventriculi

8. AV block of 2-nd degree
Wenkebach’s periods
(Mobitz II)

9. AV block of 3-rd degree

10. Other causes of interval changes
Short PR interval
preexcitation sy,
sympathetic act.,
hypoK,
AV nodal rhythms from the beginning of it
Long PR interval
AV block 1-st degree
parasympathetic act.,
hyperK,
IHD,
medicaments (e.g. beta blockers)
Short QT interval Digitalis,
hyperCa
(hyperK – tall pointing T wave)
Long QT
hypertension, after MI
hypoCa,
(hypoK– U wave),
Congenital (risk of sudden death)

11. QRS – left ventricular overload
Sokolow’s index: R in (V5 or V6) + S inV1
> 35mm
Attention young slim individuals (heart as a voltage source is closer to the chest leads – bigger voltage on the leads without hypertrophy)
Left heart hypertrophy
physiological

13. QRS – right ventricular overload
Vertical electrical axis (> 100°)
in V1: R >= 7mm or qR (volume overload)
in avR: r > 4 mm
in V6: R smaller/equal S (volume overload)
Physiological Pressure overload Physiological Volume overload

14. Pozn: Zde videt objemove pretizeni s dilataci prave komory…
Pozn: Zde videt objemove pretizeni s dilataci prave komory…. Zaroven je videt obraz pretizeni leve predsine – P mitrale…jedna se tedy o levopravy zkrat.

15. QRS - right BBB Causes: Dilatation and/or overload of right heart, MI,
sometimes “physiological”
QRS > 0,11 s
If complete, then R’(r’) wave is bigger then R(r ) in V1
Repolarization changes

17. QRS – left BBB Causes: IHD, hypertension, cardiomyopathy,
valvular disease,
unknown
QRS >0,11s (with complete block)
Discordant T! and discordant dinivelization of ST

19. QRS – Q wave myocardial infarction
In the Q-wave MI, there is necrosis throughout the cardiac wall, while in the non-Q wave, necrosis affects the endocardial zone only.
Pathological Q-wave
Appears in the first 0,04 s of QRS
Appears in the leads where there should be no Q or overlays the normal R (r) (e.g. in V1 to V5) – absence of the R-wave
Deeper then 2mm (6mm in III)
Q > 0,25 R for I, II, avL, (avF)
Q > 0,15 R forV1 to V6

21. QRS – Q wave MI
There is no Q-wave in the beginning, but so-called “Pardee’s” wave (elevation of ST+ negative T)
We imagine the (left) heart as pyramid to describe the MI location.
Anterior
Septal (right)
Lateral (left)
Inferior (down side at the apex) and it’s posterior extension (close to the base of the pyramid)

26. Combination of BBB and MI

27. QRS – serious embolism, fibrosis, hydropericardium

28. Beware – some changes are result of lead displacement