9- Electrical signals of the heart - the Electrocardiogram Flashcards
Site the main components of heart anatomy.
2 atrias
2 ventricles
Valves
Name the different type of valves in the heart
Ventricles → arteries Atria → Ventricles Tricuspid valve (re.) - Mitral-, Bicuspid valve (li.)
Site the two mains function of the heart
- Blood De/Oxygenation
- Transport of nutrients, oxygen, metabolic end
products
What are the two aims of the cardiac pathway ?
1- Controlled excitation and contraction of heart muscle 2- External modulation according to physical activity
Site the conduction pathway of the heart.
1-Sinoartrial node 2-Atrioventricular node 3-Atrioventricular bundle 4-bundle branches 5-purkinje fibers
What’s the name of the heart msucle ?
Syncytium
What’s the aim of the plateau in the AP during cardiac electrical activity ?
It inhibits the reintry of calcium ions and creates a relative refractory period where an increased threshold is necessary for reactivation
What’s the primary pacemaker in the heart ?
The sinoatrial node.
When was the electrocardiogram discovered ?
1902
What defines the P Wave ?
Depolarisation in the atria
What is the PQ interval ?
Conduction from atria to ventricles - Baseline voltage: isoelectric line
What is the QRS Complex ?
Rapid depolarisation of right and left
ventricles
What is the ST interval ?
the Total activation of the ventricles
What is the T Wave ?
Repolarisation of the ventricles,
cardiac muscle prepared for next
cycle of ECG
What is the U wave ?
- Normally low amplitude, sometimes
completely absent - Origin unclear
Describe the electrodes used in electrocorticogram.
-Stick on electrodes
-Ag/AgCl
-Single use
-Gel reduces movement
artefacts between skin
and electrode
What are the characteristics for the lead placement for einthovens triangle ?
Electrodes/leads places on limbs
Frontal plane
Bipolar
I, II,III
what are the characteristics for the lead placement in Goldberger ?
Unipolar
limb leads
frontal plane
what are the characteristics for the lead placement in wilson’s method ?
core/chest electrodes : frontal and horizontal plane,
unipolar
How and why is made an esophageal ECG
diagnostic of posterior wall of heart
unipolar
Esophageal lead
How and why are HIS-Bundle ECG made ?
Intracardiac
Diagnosis of atrial, ventricular or AV nodal
arrhythmias or conduction blocks
define Sinoatrial conduction disorders .
P wave can be postponed and ultimately some nbeats can be deleted
define atrioventricular conduction disorders
time between p wave and qrs complex can be delayed. if it is more important, we can see p wave and the rest missing till another cycle is repeated.
Define left Bundle branch
block
depol slow repol double spike
