Mean cardiac axis (cardiac vector)

Mean Cardiac Axis (Cardiac Vector)

IZADI, TAVAKOLLI, MORADI

Dr.H.R.Marateb

Department of Biomedical Engineering

Faculty of Engineering

University of Isfahan

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

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

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

Conduction System©

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Sinoatrial (SA) node

Atrioventricular (AV) node

Cardiac axis

Method

ECGUltra

sonographyX-Ray MRI

Age

Fetal Adult

©http://www.slideshare.net/NakhieeranNallasamy/ecg-27462381©http://radiopaedia.org/cases/dextrocardia-1

ECG Axis Interpretation by Ultrasonography(Echocardiography)


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

http://en.ecgpedia.org/wiki/QRS_axis

https://courses.kcumb.edu/physio/ecg primer/ecgaxis.htm


©http://www.bem.fi/book/15/15x/1509x.htm

aVf

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ECG (The Standard 12 Lead ECG)

©http://cdn.lifeinthefastlane.com/wp-content/uploads/2010/04/RAD-due-to-RVH.jpg


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

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


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


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

Related Research

Suggestions

Dextrocardia Diagnosing By Cardiac Mean Axis in Fetal ECG's

References

Mean cardiac axis (cardiac vector)

Engineering

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