1. DR. PRIYA KUBENDIRAN M-1 UNIT PROF DR.RUCKMANIS UNIT

2. BRIEF HISTORY

A 40 year old male was admitted on 10.08.09 with

c/oacute watery diarrhoea 3 days

No H/O vomiting/fever

No H/O any chest discomfort

H/O recurrent episodes of diarrhoea over the past 4 months.

Not a k/c of DM/SHT/PT/BA/IHD

3.

O/E : conscious, oriented

afebrile

pallor +

mild dehydration +

PR 110/min

BP 96/70 mm Hg

RS NVBS +, no added sounds

CVS S1 S2 +, no murmur

P/A soft, no organomegaly

CNS- NFND

4. 5. ECG TAKEN ON 10.08.09

HR 100/min

Normal sinus rhythm

Axis 70

PRinterval 0.16 s

QRS interval 0.08 s

QU 0.48 s

6.

Lab investigations :

B.urea-36 mg/dl

S.creatinine 0.7 mg/dl

S.electrolytesNa 138 meq/l

Cl -90 meq/l

Hco3 20 meq/l

K- 2.2 meq/l

ELISA for HIV1 - positive

7. 8.

Cardiac evaluation

Echocardiogram:

No RWMA

Normal Echo study

9.

After adequate hydration, i.v antibiotics and corrective measures for hypokalemia

oral KCl 15 ml tds

i.v-20 mEq/day

3 days later repeat s.potassium 4.2 mEq/L

A repeat ecg was taken

10. 11. REPEAT ECG ON 14.08.09

HR 43/min

Normal sinus rhythm

QRS axis - 60

PR interval 0.16 s

QRS interval 0.08 s

QT interval 0.48

QTc 0.41 s

12. ECG CHANGES IN HYPOKALEMIA

The ecg changes are due to

DELAYEDVENTRICULARREPOLARIZATION

Diagnosis is therefore based on ST segment, T wave & U wave abnormalities

13.

T wave

-progressive dimunition in amplitude, may eventually disappear

- a remnant of T maybe visible as a slight irregularity (minimal upward bump) on ST segment

U wave

progressive increase in amplitude & maintains its rounded appearance

may get superimposed on T-TU complex

ST segment

ST depression is seen in all leads which may be horizontal or concave upwards

14.

Prominent U waves combined with ST segment depression & flattened T waves

ROLLER COASTER EFFECT

15.

QT interval

U wave may be mistaken for a T wave leading to an incorrect diagnosis of prolonged QT interval

QT interval is usually unchanged

P wave

increase in amplitude/ duration

PR interval

1 stdegree AV block is common

Prolongation may lead to superimposition of P on TU TUP complex

2 nddegree AV block of Wenkebach type may be seen

16.

QRS complex

decreased voltage & increased duration

Arrythmias

Atrial & ventricular ectopics

Atrial tachycardia with block with AV dissociation

Ventricular tachycardia

Ventricular fibrillation

Torsades de pointes

17.

ST depression 0.5 mm

U wave amplitude > 1 mm

U wave amplitude > T wave amplitude in same lead

Typical ecg :3 features in 2 leads

Compatible ecg :2 features- U wave related characteristics is present

18. 19.