ECG in IHD
Welcome message from author
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
ECG in IHD
Topics will be covered• ECG basics• How to identify normal ECG• How to identify abnormal findings in ECG
– Atrial hypertrophy - Hyperkalaemia– Atrial fibrillation - Hypokalaemia– Atrial flutter- Pericarditis– Heart blocks– Chambers enlargement– IHD– AMI
Topics will not be covered• Signs and symptoms of the diseases with
abnormal ECG • Treatments of those diseases
What is ECG?• ECG is a medical device capable of
recording the electrical activity of the heart from electrodes placed on the skin in specific locations.
Standard ECG leads• Limb leads
Bipolar limb leads – I, II, IIIUnipolar limb leads – aVL, aVR, aVF
• Chest leadsV1 - V6
Right Arm
Right Leg
Left Leg
Left Arm
• Limb leads are typically placed on the inside of the wrists and ankles
• To help reduce artifacts you can use the upper arms and thighs
• Do not place limb leads on the torso
Limb leads
Chest Leads look at the heart in Chest Leads look at the heart in a horizontal plane.a horizontal plane.
• V1: right sternal edge (4th)V1: right sternal edge (4th)• V2: Left sternal edge (4th)V2: Left sternal edge (4th)• V4: the patient’s apex V4: the patient’s apex
beatbeat• V3: half-way b/t V2 and V4V3: half-way b/t V2 and V4• V5: anterior axillary lineV5: anterior axillary line• V6: mid-axillary lineV6: mid-axillary lineV5 and V6 are in the same V5 and V6 are in the same
horizontal plane as V4horizontal plane as V4ChestLeads
Interpretation of an ECGPatient identificationStandardization1.Rate2.Rhythm3.Axis4.P wave5.PR interval6.QRS complex7.ST segment8.T wave9.U wave10.QT interval
Conduction system of heart
Wave. Interval. Complex.• One letter = wave
– Eg = P, T• Need to check height and width
• Two letters = interval– PR interval
• Need to check length
• 3 letters = complex– QRS complex
• Need to check height, width and shape
• Name• Age • ID number• DOB• Father’s name
Patient identification and standardization
• Regular RhythmRate = 300÷numbers of large square
• Irregular RhythmNumbers of R in 6 sec x 10 (6s method)
Rate determination
Regular Rhythm
Irregular Rhythm
Using 6-sec ECG rhythm strip to calculate heart rate: 7×10 = 70 bpm.
P wave• Atrial depolarization• Best seen at Lead II• Normal Height <2 ⅟2 small square Width <2 ⅟2 small square
Causes of ST depression• Angina
• NSTEMI
• LVH
ST depression
• A – upward may be normal• B – down sloping strain / digoxin effect• C – planar ischaemia***
Angina Pectoris• Imbalance between myocardial oxygen
demand and supply• ST depression and/or T inversion
Causes of ST elevation
• AMI
• Pericarditis
Acute Myocardial Infarction• Hyper acute T • ST elevation – myocardial injury• T inversion – myocardial injury• Q wave – myocardial necrosis
Q wave• NormalLateral leads (I,aVL,V5,V6)III alone mb present1:1:4 =Physiological Q(height <1 ssq, width < 1ssq,Q <1/4 R)
-Old MI
Standard ECG leads• Limb leads
Bipolar limb leads – I, II, IIIUnipolar limb leads – aVL, aVR, aVF
• Chest leadsV1 - V6
Infarction Leads
Inferior II,III,aVF
Lateral I,aVL,V5,V6
Septal V1,V2
Anterior V1-V4
Localizing the Infarct
Inferior Infarction
• Right coronary artery
• Leads II, III, aVF
Inferior Infarction
I II III aVR aVL aVF V1 V2 V3 V4 V5 V6
Right coronary artery
Lateral Infarction
• Left circumflex artery
• I, aVL, V5, V6
• Usually associated with another infarction
Lateral Infarction
I II III aVR aVL aVF V1 V2 V3 V4 V5 V6
Left circumflex artery
Anterior Infarction
• Left anterior descending artery
• V2-V4
• V1-V4 = antero-septal infarction
• V1-V6 = extensive anterior infarction
Anterior Infarction
I II III aVR aVL aVF V1 V2 V3 V4 V5 V6
LADA
Pericarditis
T wave• Normal1/8 R < T < 2/3 R
• Tall T– Peak T wave (> 50% of preceding R)– Hyperkalaemia(Tall T , Small P, Wide QRS)
U wave• Slow repolarization of papillary muscle
• Normal – V1, V2
• Prominent U wave – hypokalaemia
Interpretation of an ECGPatient identificationStandardization1.Rate2.Rhythm3.Axis4.P wave5.PR interval6.QRS complex7.ST segment8.T wave9.U wave10.QT interval
P wave : Duration: 0.08 sec ( 2 small squares ) Height: < 2.5 mm ( 2 small squares )
PR interval: Duration: 0.12 - 0.20 sec (3-5 small squares)
QRS Complex : Duration: 0.07–0.10 sec(2 – 2½ small squares)
ST segment : Isoelectric
T wave : 1/8 previous R < T < 2/3 previous R
Important intervals and durations
Thank You
Related Documents
