Electrocardiogram Flashcards
What is the first event you can see on the EKG?
Atrial activation (depolarization) which is resembled by the P wave.
What is the second event you can see on the EKG?
The onset of the QRS complex.
What does the T wave represent on the EKG?
ventricular repolarization, but still shows upward deflection.
What does the QRS complex represent?
It represents the impulse from the AV node through the ventricles = ventricular contraction = Systole
What does the S-T segment represent?
It is the interval when ventricles are contraction, it correlates w/ plateau phase of the myocyte AP.
How are abnormal sinus rhythms calculated?
by looking at the R-R interval.
What HR is considered to be Tachycardia?
anything >100 BPM
What HR is considered to be Bradycardia?
anything <60 BPM
Does HR increase more during inhalation or exhalation?
Inhalation
How is AV block identified?
By looking at the P-R interval.
What are causes of AV block?
- Ischemia of A-V bundle
- Compression or Inflammation of A-V bundle
- Extreme vagal stimulation.
What happens during a “dropped” beat?
The atria empty but the ventricles fail to contract.
What results if a ectopic pacemaker is present?
It results in a premature atrial or ventricular contraction.
What is characteristic of a premature atrial contraction?
a premature P wave is seen which indicates the ectopic foci near the AV node, also causes a compensatory pause which discharges SA node.
What happens when the AV node becomes a ectopic pacemaker?
It creates a premature ventricular contraction because its sending the signal to the ventricles without propagating through the atria. (you get a absence of P wave)
What is ventricular fibrillation?
Complete asynchrony of ventricles, which does not allow them to coordinate a normal contraction.
How do you correct ventricular fibrillation?
With Defibrillation (completely shocks the heart and allows for everything to depolarize “reset”)
What are causes of ventricular fibrillation?
sudden electric shock
Ischemia
What is Atrial Fibrillation?
The ventricular filling time is compromised, and does not allow for a proper contraction. Can live with AFib.
What causes Atrial Fibrillation?
It is caused by many ectopic foci.
What is Atrial Flutter?
It can be asymptomatic or patient can experience palpitations. Usually can physically feel heart beating.
True or False: Atrial Fibrillation and Atrial Flutter are the same thing.
False
