Mean cardiac axis (cardiac vector)

1. Mean Cardiac Axis
(Cardiac Vector)
IZADI, TAVAKOLLI, MORADI
Dr.H.R.Marateb
Department of Biomedical Engineering
Faculty of Engineering
University of Isfahan

2. Table of Contents
Heart, Structure ,Function and Location of ESH
Cardiac axis
Estimating the cardiac (QRS) axis
Causes of Axis Deviation
Diagnosing by Cardiac Axis
Related Research
Reference

3. Heart
• It is a little larger than the size of your fist
• Heart is the most hard-working muscle.
• Components of the heart :
©http://my.clevelandclinic.org/ccf/media/Images/heart/coronaryarteriesnew.jpg

4. Structure ,Function and Location of ESH
• Sinoatrial (SA) node
• Internodal pathways
• Atrioventricular (AV) node
• Bundle of His
• Left bundle branch
• Right bundle branch
• Purkinje system
©http://my.clevelandclinic.org/ccf/media/Images/heart/coronaryarteriesnew.jpg

5. Conduction System
©http://theodysseyonline.com/springfield/7-things-wish-knew-before-living-massachusetts/225376
Sinoatrial (SA) node
Atrioventricular (AV) node

6. Cardiac axis
Method
ECG
Ultra
sonography
X-Ray MRI
Age
Fetal Adult
©http://www.slideshare.net/NakhieeranNallasamy/ecg-27462381©http://radiopaedia.org/cases/dextrocardia-1

7. ECG Axis Interpretation by Ultrasonography
(Echocardiography)

8. Estimating the cardiac (QRS) axis
Method 1 – The Quadrant Method
Method 2 – Leads I + II
Method 3 – The Isoelectric Lead
S. Meek and F. Morris,"Introduction to leads, rate, rhythm, and cardiac axis“ British Medical Journal,
vol. 324, p. 415, 2002.
http://en.ecgpedia.org/wiki/QRS_axis
https://courses.kcumb.edu/physio/ecg%20primer/ecgaxis.htm

9. Estimating the cardiac (QRS) axis
©http://www.bem.fi/book/15/15x/1509x.htm
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10. ECG (The Standard 12 Lead ECG)
©http://cdn.lifeinthefastlane.com/wp-content/uploads/2010/04/RAD-due-to-RVH.jpg

11. Estimating the cardiac (QRS) axis
Height of Q wave: -0.5 mm
+ Height of R wave: +8.0 mm
+ Height of S wave: 0.0 mm
____________________________
+ 7.5 mm
©http://cdn.lifeinthefastlane.com/wp-content/uploads/2010/04/RAD-due-to-RVH.jpg
MEAN CARDIAC AXIS

12. ECG Axis Interpretation
•Normal Axis = between -30 and +90 degrees.
•Extreme Axis Deviation = between -90 and 180 degrees
•Right Axis Deviation = greater than +90 degrees.
•Left Axis Deviation = less than -30 degrees.
•Borderline left axis deviation
©http://www.slideshare.net/NakhieeranNallasamy/ecg-27462381

13. Causes of Axis Deviation
Right Axis Deviation
• Right ventricular hypertrophy
• Chronic lung disease, e.g. COPD
• Hyperkalaemia: Renal insufficiency and K
• Dextrocardia
• Wolff-Parkinson-White syndrome
• Ventricular ectopy
• Sodium-channel blockade, e.g. TCA poisoning
• Acute right ventricular strain
• Lateral STEMI
• Secundum ASD – rSR’ pattern
• Normal paediatric ECG
• Left posterior fascicular block – diagnosis of exclusion
• Vertically orientated heart – tall, thin patient

14. Causes of Axis Deviation
Left Axis Deviation
• Left ventricular hypertrophy
• Left bundle branch block
• Inferior MI
• Wolff-Parkinson-White Syndrome
• Ventricular pacing /ectopy
• Primum ASD – rSR’ pattern
• Left anterior fascicular block – diagnosis of exclusion
• Horizontally orientated heart – short, squat patient
Extreme Axis Deviation
• Ventricular rhythms – e.g.VT, AIVR, ventricular ectopy
• Hyperkalaemia
• Severe right ventricular hypertrophy

15. Related Research

16. Related Research

17. Related Research

18. Suggestions
Dextrocardia Diagnosing By Cardiac Mean Axis in Fetal ECG's

19. References