Ecg abnormalities

1. ECG &
ABNORMALITY
Presented by : Dr Arnab
Banerjee
Moderator : Dr Shailendra

2. RATE ABNORMALITIES
• Normal heart rate is between 60 beats/min to 100 beats/min for adults
• More than 100/min is tachycardia and less than 60/min is bradycardia
• Combination of both seen in tachy brady syndrome
• Can be physiologic like sleeping brady, athletes
• Can increase physiologicaly with pregnancy,activities etc

3. ATRIAL ENLARGEMENTS
• Right atrial enlargement produces a tall p wave of more than 2.5mm in amplitude
• It is known as p pulmonale
• Left atrial enlargement produces wide p waves more than .12 sec
• It is called p mitrale.
• Bi atrial enlargement produces wide and tall p waves

4. VENTRICULAR ENLARGEMENT
• In right ventricular hypertrophy instead of of the rS pattern in lead V1, there is tall
R waves ,along with RAD and T wave inversion in right to mid precordial leads.

5. • Left ventricular hypertrophy produces deep S wave in V1 and tall R waves in v6, it
is exaggeration of the normal pattern.
• Voltage criteria : Sv1 + Rv6 >35mm or Rv6 >25mm
• R wave more than 11 – 13 mm in lead aVL
• May be associated with LAD or LBBB
• Broad LA and biphasic p wave in V1
• Bi ventricular enlargement show pattern of LVH predominantly or LVH with RAD

6. RHYTHM ABNORMALITIES
• Junctional rhythm : ventricular contraction is controlled by AV node , QRS hides P
nodes.
• Idioventricular rhythm : ventricular contractions controlled by purkinjee fibres,
wide QRS and QRS independent of P waves.

8. AV BLOCKS
• First degree AV block : uniform slowing of conduction between atria and ventricle,
prolongation of PR interval.
• Second degree AV block: intermittent interruption of conduction, Mobitz 1 and
Mobitz 2
• Third degree AV block : complete AV dissociation

12. BUNDLE BRANCH BLOCK
• RBBB : lead V1 shows rsR’ pattern with wide R’ wave. Lead V6 shows qRS pattern
with a wide S wave. T wave inversion can be seen in right sided chest leads.
• Complete rbbb has qrs width of > 0.12sec incomplete rbbb has width between 0.10-
0.12 sec
• Lbbb : lead V1 shows wide entirely negative QS complex (rarely a wide rS complex)
lead V6 shows wide tall R wave without a q wave.
• Complete lbbb has qrs width of > 0.12sec incomplete lbbb has width between 0.10-
0.12 sec

15. • Left anterior fascicular block result in marked LAD(-45 or more negative) , left posterior fascicular
block result into marked RAD(+120 or more positive)

16. • Biphasicular and trifascicular block : RBBB with LAFB produces an RBBB with
marked LAD. RBBB with LPFB produces an RBBB pattern with marked RAD.
• Trifascicular block produces complete AV block.

18. ELECTROLYTE DISTURBANCES
• Hyperkalemia : normal serum potassium level is between 3.5 to 5meq/l.
• 1st sign of hyperkalemia is tall peaked t waves.with further increament the PR
interval lengthens and P waves may disappear. Further increament cause AV
conduction delay with widening of QRS width.
• Eventually leading to large undulating sine wave pattern and asystole with cardiac
arrest.

21. • Hypokalemia : most common pattern is ST depression with prominent U waves and
prolonged repolarization.

22. HYPOCALCEMIA AND HYPERCALCEMIA

24. ARRYTHMIAS
• Supra ventricular arrythmias :

25. • Atrial Tachycardia
• Classical atrial tachycardia (AT) is defined as three or more consecutive APBs coming
from a single atrial focus and having identical nonsinus P wave morphology. A variant is
multifocal AT, in which the P waves vary because they come from different firing
sites.

26. • AV Nodal Reentrant (Reentry) Tachycardia
• AV nodal reentrant (reentry) tachycardia (AVNRT) is a supraventricular arrhythmia,
usually paroxysmal, resulting from the reentry in the AV node area.

27. • Atrioventricular Reentrant (Bypass Tract–Mediated)
Tachycardia
• Atrioventricular reentrant (bypass tract–mediated) tachycardia (AVRT), the third most
common cause of PSVT, involves an accessory atrioventricular bypass tract (see
Chapter 12), which provides the substrate for reentry.

28. • ATRIAL FLUTTER
• The reentrant circuit of atrial flutter revolves around the tricuspid valve in the right
atrium, it is initiated by a premature atrial complex (PAC) that blocks in one
direction, while propagating in another. The signal then keeps circling in the same
trajectory over and over again.

29. • ATRIAL FIBRILLATION
• Unlike atrial flutter, the reentrant waves of atrial fibrillation (AF) cannot be localized to
any repetitive and stable circuit in the atria.

30. • VENTRICULAR TACHYCARDIAS
• The usual definition of VT is three or more VPBs in a row at a rate of 100 or more
beats/min
• Monomorphic: all QRS complexes look the same in a given lead
• Polymorphic: QRS shapes, directions, and sometimes rate vary from beat to beat
• Nonsustained ventricular tachycardia (VT): lasting 30 sec or less
• Sustained VT: longer than 30 sec or requiring direct current (DC) shock due to
hemodynamic instability

32. • VENTRICULAR FIBRILLATION
• Ventricular fibrillation is a completely disorganized ventricular rhythm resulting in
immediate cessation of cardiac output and cardiac arrest.

34. MYOCARDIAL INFARCTION

39. RECOGNITION OF MI
• What to look for : ST segment elevation > 1mm and in two contiguous leads.
• Where to look for : I, AVL , V5 , V6 –lateral
• V1 – V4 – anterior
• II, III, AVF - inferior

42. LOCATION OF INFARCT COMBINATION

50. CONCLUSION
• Ecg is a basic and easy investigation to identify many pathologic condition of heart
• An acute MI can occur with normal ecg
• Diagnosis of acute or old anterior MI with a LBBB can be difficult but not imposible
• Serial ecg changes is of more value in acute coronary syndrome

51. THANK YOU