ECG- ST segment

ECG
ST segment

1. MBBS, FCPS, MD, FACC, FESC, FRCP, FSCAI,
FCCP,FAPSC, FAPSIC, FAHA,FACP,FASE
Professor and Head of Cardiology
Colonel MalekMedical College , Manikganj.
For under-graduates
[email protected]/11/2019
Under graduate version 2019

2. [email protected]
28.11.2019 CMMC-02 ECG Lecture 08
ST segment
Professor DrMdToufiqurRahman
•TheST segmentis the flat, isoelectric section of
the ECG between the end of the S wave (the J
point) and the beginning of the T wave.
•The ST Segment represents the interval
between ventricular depolarization and
repolarization.
•The most important cause of ST segment
abnormality (elevation or depression)
ismyocardial ischaemiaorinfarction.

3. [email protected]
28.11.2019 CMMC-02 ECG Lecture 08
ST segment
Professor DrMdToufiqurRahman

4. [email protected]
28.11.2019 CMMC-02 ECG Lecture 08
ST segment
Professor DrMdToufiqurRahman
Causes of ST Segment Elevation
•Acute myocardial infarction
•Coronary vasospasm (Printzmetal’sangina)
•Pericarditis
•Benign early repolarization
•Left bundle branch block
•Left ventricular hypertrophy
•Ventricular aneurysm
•Brugadasyndrome
•Ventricular paced rhythm
•Raised intracranial pressure
•TakotsuboCardiomyopathy

5. [email protected]
28.11.2019 CMMC-02 ECG Lecture 08
ST segment
Professor DrMdToufiqurRahman
Morphology of the Elevated ST segment
Myocardial Infarction
Acute STEMI may
produce ST elevation
with either concave,
convex or obliquely
straight morphology.

6. [email protected]
28.11.2019 CMMC-02 ECG Lecture 08
ST segment
Professor DrMdToufiqurRahman
Morphology of the Elevated ST segment

7. [email protected]
28.11.2019 CMMC-02 ECG Lecture 08
ST segment
Professor DrMdToufiqurRahman
Morphology of the Elevated ST segment

8. [email protected]
21.11.2019 CMMC-02 ECG Lecture 07
ST segment
Professor DrMdToufiqurRahman
Morphology of the Elevated ST segment
Patterns of ST Elevation
Acute ST elevation myocardial infarction (STEMI)
ST segment elevation and Q-wave formation in contiguous
leads.
•Septal(V1-2)
•Anterior (V3-4)
•Lateral (I + aVL, V5-6)
•Inferior (II, III, aVF)
•Right ventricular (V1, V4R)
•Posterior (V7-9)

9. [email protected]
21.11.2019 CMMC-02 ECG Lecture 07
ST segment
Professor DrMdToufiqurRahman
Morphology of the Elevated ST segment
Acute ST elevation myocardial infarction (STEMI)
There is usuallyreciprocal ST depressionin the electrically
opposite leads. For example, STE in the high lateral leads I +
aVLtypically produces reciprocal ST depression in lead III

10. [email protected]
28.11.2019 CMMC-02 ECG Lecture 08
ST segment
Professor DrMdToufiqurRahman
Coronary Vasospasm (Prinzmetal’sangina)
•This causes a pattern of ST elevation that is very
similar to acute STEMI —i.e. localisedST elevation
with reciprocal ST depression occurring during
episodes of chest pain.
•However, unlike acute STEMI the ECG changes are
transient, reversible with vasodilators and not
usually associated with myocardial necrosis.
•It may be impossible to differentiate these two
conditions based on the ECG alone.

11. [email protected]
21.11.2019 CMMC-02 ECG Lecture 07
ST segment
Professor DrMdToufiqurRahman
Pericarditis
•Acute Pericarditiscauses widespread
concave (“saddleback”) ST segment elevation
withPR segment depressionin multiple
leads, typically involving I, II, III, aVF, aVL, and
V2-6.
•Spodick’ssignwas first described byDavid H.
Spodickin 1974 as a downward sloping TP
segment with specificity for acute pericarditis.

12. [email protected]
21.11.2019 CMMC-02 ECG Lecture 07
ST segment
Professor DrMdToufiqurRahman
Pericarditis
Concave “saddleback” ST elevation in leads I, II, III, aVF, V5-6
with depressed PR segments. There is reciprocal ST
depression and PR elevation in leads aVRand V1.

13. [email protected]
28.11.2019 CMMC-02 ECG Lecture 08
ST segment
Professor DrMdToufiqurRahman
Benign Early Repolarization
•Benign Early Repolarization(BER) causes mild ST
elevation with tall T-waves mainly in the precordial
leads.
•BER is a normal variant commonly seen in young,
healthy patients.
•There is often notching of theJ-point—the “fish-
hook” pattern.
•The ST changes may be more prominent at slower heart
rates and disappear in the presence of tachycardia.

14. [email protected]
28.11.2019 CMMC-02 ECG Lecture 8
ST segment
Professor DrMdToufiqurRahman
Benign Early Repolarization
There is slight concave ST elevation in the precordial and inferior leads
with notching of the J-point (the “fish-hook” pattern)

15. [email protected]
28.11.2019 CMMC-02 ECG Lecture 08
ST segment
Professor DrMdToufiqurRahman
Left Bundle Branch Block (LBBB)
•InLeft bundle branch block(LBBB), the ST
segments and T waves show “appropriate
discordance” —i.e. they are directed opposite to
the main vector of the QRS complex.
•This produces ST elevation and upright T waves in
leads with a negative QRS complex (dominant S
wave), while producing ST depression and T wave
inversion in leads with a positive QRS complex
(dominant R wave).

16. [email protected]
28.11.2019 CMMC-02 ECG Lecture 08
ST segment
Professor DrMdToufiqurRahman
Left Bundle Branch Block (LBBB)
ST elevation in leads with deep S waves —most apparent in V1-3.
ST depression in leads with tall R waves —most apparent in I and
aVL.

17. [email protected]
28.11.2019 CMMC-02 ECG Lecture 08
ST segment
Professor DrMdToufiqurRahman
Left Ventricular Hypertrophy (LVH)
Left Ventricular Hypertrophy(LVH)
causes a similar pattern of
repolarization abnormalities as LBBB,
with ST elevation in the leads with
deep S-waves (usually V1-3) and ST
depression/T-wave inversion in the
leads with tall R waves (I, aVL, V5-6).

18. [email protected]
28.11.2019 CMMC-02 ECG Lecture 08
ST segment
Professor DrMdToufiqurRahman
Left Ventricular Hypertrophy (LVH)
•Deep S waves with ST elevation in V1-3
•ST depression and T-wave inversion in the lateral leads V5-6
•there is alsoright axis deviation, which is unusual for LVH and may
be due to associatedleft posterior fascicular block

19. [email protected]
28.11.2019 CMMC-02 ECG Lecture 08
ST segment
Professor DrMdToufiqurRahman
Ventricular Aneurysm
•Ventricular Aneurysm–residual ST
elevation and deep Q waves seen in
patients with previous myocardial
infarction.
•It is associated with extensive myocardial
damage and paradoxical movement of the
left ventricular wall during systole.

20. [email protected]
28.11.2019 CMMC-02 ECG Lecture 08
ST segment
Professor DrMdToufiqurRahman
Ventricular Aneurysm
•ST elevation with deep Q waves and inverted T waves in V1-3.
•This pattern suggests the presence of a left ventricular aneurysm
due to a prior anteroseptalMI.

21. [email protected]
28.11.2019 CMMC-02 ECG Lecture 08
ST segment
Professor DrMdToufiqurRahman
BrugadaSyndrome
•BrugadaSyndromeis an inherited
channelopathy(a disease of myocardial
sodium channels) that leads to paroxysmal
ventricular arrhythmias and sudden cardiac
death in young patients.
•The tell-tale sign on the resting ECG is the
“Brugadasign” —ST elevation and partial
RBBB in V1-2 with a “coved” morphology.

22. [email protected]
28.11.2019 CMMC-02 ECG Lecture 08
ST segment
Professor DrMdToufiqurRahman
BrugadaSyndrome
•ST elevation and partial RBBB in V1-2 with a coved
morphology —the “Brugadasign”.

23. [email protected]
21.11.2019 CMMC-02 ECG Lecture 07
ST segment
Professor DrMdToufiqurRahman
Ventricular Paced Rhythm
Ventricular pacing(with a pacing wire in
the right ventricle) causes ST segment
abnormalities identical to that seen in
LBBB.
There isappropriate discordance, with the
ST segment and T wave directed opposite
to the main vector of the QRS complex.

24. [email protected]
28.11.2019 CMMC-02 ECG Lecture 08
ST segment
Professor DrMdToufiqurRahman
Ventricular Paced Rhythm
There isappropriate discordance, with the ST segment and T wave
directed opposite to the main vector of the QRS complex.

25. [email protected]
28.11.2019 CMMC-02 ECG Lecture 08
ST segment
Professor DrMdToufiqurRahman
Raised Intracranial Pressure
•Raised Intracranial Pressure(ICP) (e.g. due
to intracranial haemorrhage, traumatic
brain injury) may cause ST elevation or
depression that simulates myocardial
ischaemiaor pericarditis.
•More commonly, raised ICP is associated
with widespread, deep T-wave inversions
(“cerebral T waves“).

26. [email protected]
28.11.2019 CMMC-02 ECG Lecture 08
ST segment
Professor DrMdToufiqurRahman
Raised Intracranial Pressure
Widespread ST elevation with concave (pericarditis-like) morphology
in a patient with severe traumatic brain injury

27. [email protected]
28.11.2019 CMMC-02 ECG Lecture 08
ST segment
Professor DrMdToufiqurRahman
TakotsuboCardiomyopathy
•TakotsuboCardiomyopathy, A STEMI mimic
producing ischaemicchest pain, ECG changes +/-
elevated cardiac enzymes with characteristic
regional wall motion abnormalities on
echocardiography.
•Typically occurs in the context of severe
emotional distress (“broken heart syndrome“).
Commonly associated with new ECG changes (ST
elevation or T wave inversion) or moderate
troponin rise.

28. [email protected]
21.11.2019 CMMC-02 ECG Lecture 07
ST segment
Professor DrMdToufiqurRahman
TakotsuboCardiomyopathy

29. [email protected]
21.11.2019 CMMC-02 ECG Lecture 07
ST segment
Professor DrMdToufiqurRahman
Less Common Causes of ST segment Elevation
•Pulmonary embolismand acute corpulmonale(usually in
lead III)
•Acute aortic dissection (classically causesinferior
STEMIdue to RCA dissection)
•Hyperkalaemia
•Sodium-channel blocking drugs(secondary to QRS
widening)
•J-waves(hypothermia,hypercalcaemia)
•Following electrical cardioversion
•Others: Cardiac tumour, myocarditis, pancreas or
gallbladder disease

30. [email protected]
28.11.2019 CMMC-02 ECG Lecture 08
ST segment
Professor DrMdToufiqurRahman
TransientSTelevationafterDC
cardioversionfromVF

31. [email protected]
21.11.2019 CMMC-02 ECG Lecture 07
ST segment
Professor DrMdToufiqurRahman
J waves in hypothermia simulating
ST elevation

32. [email protected]
21.11.2019 CMMC-02 ECG Lecture 07
ST segment
Professor DrMdToufiqurRahman
Causes of ST Depression
•Myocardial ischaemia/ NSTEMI
•Reciprocal change in STEMI Posterior MI
•Digoxin effect
•Hypokalaemia
•Supraventricular tachycardia
•Right bundle branch block
•Right ventricular hypertrophy
•Left bundle branch block
•Left ventricular hypertrophy
•Ventricular paced rhythm

33. [email protected]
28.11.2019 CMMC-02 ECG Lecture 08
ST segment
Professor DrMdToufiqurRahman
Morphology of ST Depression
•ST depression can be either upsloping,
downsloping, or horizontal.
•Horizontal or downslopingST depression ≥ 0.5 mm
at the J-point in ≥ 2 contiguous leads indicates
myocardial ischaemia(according to the2007 Task
Force Criteria).
•UpslopingST depression in the precordial leads
with prominentDe Winter T wavesis highly
specific for occlusion of the LAD.

34. [email protected]
28.11.2019 CMMC-02 ECG Lecture 08
ST segment
Professor DrMdToufiqurRahman
Morphology of ST Depression
•Reciprocal change has a morphology that
resembles “upside down” ST elevation and is
seen in leads electrically opposite to the site
of infarction.
•Posterior MI manifests as horizontal ST
depression in V1-3 and is associated with
upright T waves and tall R waves.

35. [email protected]
28.11.2019 CMMC-02 ECG Lecture 08
ST segment
Professor DrMdToufiqurRahman
Morphology of ST Depression

36. [email protected]
28.11.2019 CMMC-02 ECG Lecture 08
ST segment
Professor DrMdToufiqurRahman
Morphology of ST Depression
ST segment morphology in myocardial ischaemia

37. [email protected]
28.11.2019 CMMC-02 ECG Lecture 08
ST segment
Professor DrMdToufiqurRahman
Morphology of ST Depression
Reciprocal change

38. [email protected]
28.11.2019 CMMC-02 ECG Lecture 08
ST segment
Professor DrMdToufiqurRahman
Morphology of ST Depression
ST segment morphology in posterior MI

39. [email protected]
28.11.2019 CMMC-02 ECG Lecture 08
ST segment
Professor DrMdToufiqurRahman
Morphology of ST Depression
MyocardialIschaemia
•STdepressionduetosubendocardial
ischaemiamaybepresentinavariablenumberof
leadsandwithvariablemorphology.
•Itisoftenmostprominentintheleftprecordial
leadsV4-6plusleadsI,IIandaVL.
•WidespreadSTdepressionwithSTelevationin
aVRisseeninleftmaincoronaryartery
occlusionandseveretriplevesseldisease.

40. [email protected]
28.11.2019 CMMC-02 ECG Lecture 08
ST segment
Professor DrMdToufiqurRahman
Morphology of ST Depression
Myocardial Ischaemia
ST depression localisedto the inferior or high lateral leads is more likely to
represent reciprocal change than subendocardialischaemia

41. [email protected]
28.11.2019 CMMC-02 ECG Lecture 08
ST segment
Professor DrMdToufiqurRahman
Morphology of ST Depression
ReciprocalChange
•STelevationduringacuteSTEMIisassociatedwith
simultaneousSTdepressionintheelectricallyopposite
leads.
•InferiorSTEMIproducesreciprocalSTdepressioninaVL
(±leadI).
•LateraloranterolateralSTEMIproducesreciprocalST
depressioninIIIandaVF(±leadII).
•ReciprocalSTdepressioninV1-3occurswithposterior
infarction

42. [email protected]
28.11.2019 CMMC-02 ECG Lecture 08
ST segment
Professor DrMdToufiqurRahman
Morphology of ST Depression
Reciprocal Change
Reciprocal ST depression in aVLwith inferior STEMI

43. [email protected]
28.11.2019 CMMC-02 ECG Lecture 08
ST segment
Professor DrMdToufiqurRahman
Morphology of ST Depression
Reciprocal Change
Reciprocal ST depression in III and aVFwith high lateral STEMI

44. [email protected]
28.11.2019 CMMC-02 ECG Lecture 08
ST segment
Professor DrMdToufiqurRahman
Posterior Myocardial Infarction
AcuteposteriorSTEMIcausesSTdepressionintheanteriorleadsV1-
3,alongwithdominantRwaves(“Q-waveequivalent”)anduprightT
waves.ThereisSTelevationintheposteriorleadsV7-9.

45. [email protected]
28.11.2019 CMMC-02 ECG Lecture 08
ST segment
Professor DrMdToufiqurRahman
De Winter T Waves
DeWinterTwaves:apatternofup-slopingSTdepressionwith
symmetricallypeakedTwavesintheprecordialleadsisconsideredto
beaSTEMIequivalent,andishighlyspecificforanacuteocclusionof
theLAD.

46. [email protected]
28.11.2019 CMMC-02 ECG Lecture 08
ST segment
Professor DrMdToufiqurRahman
Digoxin Effect
DigoxinEffect:Treatmentwithdigoxincausesdownsloping
STdepressionwitha“sagging”morphology,reminiscentof
SalvadorDali’smoustache.

47. [email protected]
28.11.2019 CMMC-02 ECG Lecture 08
ST segment
Professor DrMdToufiqurRahman
Hypokalaemia
HypokalaemiacauseswidespreaddownslopingST
depressionwithT-waveflattening/inversion,prominentU
wavesandaprolongedQUinterval.

48. [email protected]
28.11.2019 CMMC-02 ECG Lecture 08
ST segment
Professor DrMdToufiqurRahman
Right ventricular hypertrophy (RVH)
Right ventricular hypertrophy(RVH) causes ST depression
and T-wave inversion in the right precordial leads V1-3.

49. [email protected]
28.11.2019 CMMC-02 ECG Lecture 08
ST segment
Professor DrMdToufiqurRahman
Right Bundle Branch Block (RBBB)
Right Bundle Branch Block(RBBB) may produce a similar
pattern of repolarisationabnormalities to RVH, with ST
depression and T wave inversion in V1-3.

50. [email protected]
28.11.2019 CMMC-02 ECG Lecture 08
ST segment
Professor DrMdToufiqurRahman
Supraventricular tachycardia (SVT)

51. [email protected]
28.11.2019 CMMC-02 ECG Lecture 08
ST segment
Professor DrMdToufiqurRahman
Supraventricular tachycardia (SVT)
Supraventriculartachycardia(e.g.AVNRT)typicallycauseswidespreadhorizontalST
depression,mostprominentintheleftprecordialleads(V4-6).
Thisrate-relatedSTdepressiondoesnotnecessarilyindicatethepresenceof
myocardialischaemia,providedthatitresolveswithtreatment.