Interpreting ECG using 10 steps including 2 cases in remote general practice.

1. Case-Based ECG
Hung The Nguyen
hung@hmvtteachingspace.com

2. Outline
‣10 Steps ECG
‣2 cases from the bush

3. Ten Steps ECG
‣name, age, sex
‣time performed
‣chest pain?
‣BP
‣digoxin?
1.Importantbasicinformation

4. ‣300/number of big
squares
2.Rate Ten Steps ECG

5. ‣ sinus rhythm
‣ ectopics, premature beats
‣ narrow based arrhythmias;
➡ AF, atrial flutter
➡ SVT
‣ broad based arrhythmias:
➡ VT, VF
‣ asytole
3.Rhythm Ten Steps ECG
Does this
ECG look
right?

6. ‣look at leads II, III, aVF, V1
‣P pulmonale
➡amp >3 mm = RA
dilatation eg pulmonary HT
(COAD, secondary LVF)
‣P mitrale
➡notched P wave and sinus
wave inV1 >1 mm = MR, MS
4.Pwave Ten Steps ECG

7. ‣AV node conduction,
normally 3-5 mm (0.12 to
0.2 sec)
‣shortened
➡accessory pathway =
WPW (delta wave)
➡Digoxin,
➡hyper Ca, K, Mg
5.PRinterval Ten Steps ECG

8. 5.PRinterval Ten Steps ECG

9. ‣prolonged
➡1st degree heart block (constant
prolonged PR int) = past inf and ant
AMI, drugs (B-blocker, Digoxin, Ca
channel blockers), age related,
rheumatic fever
➡2nd degree HB – Mobitz type I
(Wenkebach); Mobitz type II can
progress to complete HB
➡3rd HB – atrial rate (P) 100-300,
ventricular rate (QRS) 30-40
5.PRinterval Ten Steps ECG

10. ‣Presence of the Q wave
Physiological Q <1mm, ¼ height of R
Pathological Q = AMI
➡Lead II, III, aVF = inferior wall;
➡Lead I, aVL,V3-4 = anterior wall;
➡LeadV1-2 = septal wall
➡LeadV5-6 = lateral wall
Q+ = full thickness AMI, Q- = subendocardial AMI
6.QRScomplex Ten Steps ECG

11. ‣Amplitude
<10 mm inV leads;
V1 R = RV, S = LV;
V6 Q = septum, R = LV, S = RV
determined by amount of fluid (pericardial
effusion), fat (breast, obesity), air
(emphysema);
determined by strength of signal (heart failure)
➡LVH =V1orV2 S plusV6 orV5 > 35 mm
➡RVH R>S inV1 plus prominent S inV6
➡Prominent R wave in V1 = post AMI, RVH,
WPW, RBBB, PE
6.QRScomplex Ten Steps ECG

12. ‣Duration
<3 mm (0.12)
for BBB look at I,V1,V6 (note
cannot Dx AMI, LVH when LBBB
or RBBB present)
➡RBBB ↑S in I,V6 plus rSR’ inV1
(MaRRoW)
➡LBBB ↑R in I,V6 plus ↑S inV1
(WiLLiaM)
6.QRScomplex Ten Steps ECG

13. ‣Axis deviation
Physiological = pregnant, tall and
thin (short and obese)
Pathological
➡ant fascicular damage, left ant
hemiblock (LAXD);
➡post fascicular damage, left post
hemiblock (RAXD);
➡MI (necrosis),
➡HT (hypertrophy)
6.QRScomplex
N LAXD RAXD
I ↑ ↑ ↓
II ↑ ↓ ↓
III ↓ ↓ ↑
Ten Steps ECG

14. Absolute refractory period
‣Depression
➡Angina
Exercise stress test – peak performance HR 200-age, SBP
+60, DBP stay the same or ↓, monitorV5 + when >1 mm
depression 2 mm after the J point;
2/3 women have + exercise stress with normal coronary
arteries
➡LV strain
Severe LVH; signs of LVH with ST ↓ in anterolat leads = HT
➡LBBB
➡Digoxin
‣ST sag
7.STsegment Ten Steps ECG

15. Elevated
‣AMI
‣Ant
‣Inf – RCA 95%, CXA 5% →1st degree
HB (AV nodal art)
➡Variant angina – ST↑ without ↑cardiac
enzymes
➡LV aneurysm – persistent ↑ST
➡Pericarditis – widespread ST↑, saddled
shaped
7.STsegment Ten Steps ECG

16. ‣inversion T in leads III,
aVR, aVF, V1-2, can be
normal
‣normal if in the same
direction as QRS and
amplitude <10 mm inV
leads
8.Twave Ten Steps ECG

17. Repol of septum/papillary
muscle inV2-V4 septal
leads
9.Uwave Ten Steps ECG

18. Depol and repol time
<1/2 RR interval
QTc = QT/√RR <0.44 sec
‣Prolonged
➡↑risk ofVT (torsade de point)
➡familial,
➡electrolyte imbalance (K. Mg, Ca),
➡drugs (phenothiazines,TCA, ventricular
anti-arrhythmic drugs = 10% risk of pro-
arrhythmia)
‣Shortened
No clinical significance
10.QTinterval Ten Steps ECG

19. Thomasina
‣ Thomasina is a 10 year old girl presenting
with her grandmother. She is visiting a
Community Health Clinic in a remote
Aboriginal community.
‣ The grandmother says to you in broken
English that she is very worried about
Thomasina who is having strange
movements of her hands. “She’s going mad!”

20. Thomasina
‣ with further questioning she is feeling
unwell, lethargic and has a mild fever.
‣ she complained of sore elbows and wrists.
she also had sore knees as few days ago but
it has abated.
‣ she never had this before

21. Thomasina
‣ When you examine her, she was short of breath (RR
20), HR= 92
‣ she has jerky and uncoordinated movements of her
right upper limb. She says that she cannot control it.
‣ her elbow and wrist joints are tender but not
swollen
‣ she had no rash
‣ she does not have a heart murmur

22. Thomasina
‣ you did the following tests according to the
CARPA Standard Treatment Manual:
‣ throat swab MCS
‣ bloods for ASOT, ANTiDNAse B, CRP,
FBC, ESR, blood cultures
‣ ECG

23. Thomasina

24. Thomasina
6 mm

25. Thomasina
‣ you give her paracetamol

26. Thomasina
‣ you call the DMO and discussed the case
‣ Thomasina will be evacuated by plane

27. Thomasina
‣ when she returned to the community, you instruct
the health staff to put her on the rheumatic fever,
heart disease list
‣ Thomosina will have Bicillin LA 2 ml IM every 4
weeks until she is 21 years of age
‣ she will need to see a doctor every year for review
‣ she is to have pneumococcal and flu vaccines
‣ she is to see the dentist once a year

28. Frank
‣ You are having a restful Friday afternoon in
remote Aboriginal Community Health
Centre. This is quite unusual but
welcomed.
‣ Frank came in wondering if the clinic is
opened. He said that he is the pilot of the
mail plane that just arrived and he is having
trouble breathing.

29. Frank
‣ Frank is a 40 year old pilot for 20 years.
‣ he is healthy and fit.
‣ he says that he suddenly developed short of
breath and palpitations just before he
landed the plane in your community. He
feels faint and worries that he is having a
heart attack.

30. Frank
‣ he does not have chest pain.
‣ he has no reasons to be stressed or
anxious.
‣ he drinks coffee 4 times a day
‣ takes no alcohol nor does he smoke

31. Frank
‣ you examine him and found that he is short
of breath (RR 24) and tachycardic (HR
150), afebrile, with a BP = 130/80
‣ his cardiac examination is normal and he is
not in heart failure

32. Frank
‣ you asked the nurse to do a 12 lead ECG

33. Frank

34. Frank
‣ you tell Frank that he has SVT and that you
will need him to help you slow the heart
rate down
‣ you ask him to perform a valsalva
manoeuvre
‣ after a few goes, it did not work

35. Frank
‣ you tell Frank that there is something else
you can try called the “carotid sinus
massage”
‣ he asks “What happens if that doesn’t
work?”

36. Frank
‣ you tell him that there are drugs that can
slow the heart down.“Lets not think about
those until we have to,” you said to him.
‣ you proceed to perform the carotid sinus
massage

37. Frank
‣ his heart rate is now in sinus rhythm!

38. Frank
‣ He thanks you for an exceptional job, asked
whether he needs to pay for anything and
proceeded to walk out the of the clinic.

39. Frank
‣ unfortunately for Frank, you stopped him
and told him that he cannot fly today and
you have to let the authorities know about
his condition
‣ you arranged for another plane to fly him
home.

40. Close
‣10 Steps ECG
‣2 cases from the bush

41. hung@hmvtteachingspace.com