Basic EKG (Exam #1) Flashcards
What is the ability to produce an electrical impulse without outside nerve stimulation?
Automaticity
What is the ability to respond to electrical stimulus?
Excitability
What is the ability to transmit electrical stimulus from cell-to-cell?
Conductivity
What is ability to contract when electrically stimulated?
Contractibility
What phase of the cardiac cycle does systole correlate with? Diastole?
- Systole = contraction
- Diastole = relaxation
What ANS system is the cardioaccelerator, and what NT(s) is released?
Sympathetic
- Adrenergic (NE, Epi)
What ANS system is the cardioinhibitor, and what NT(s) is released (via what)?
Parasympathetic
- Cholinergic (ACh) via Vagus n.
What is the intrinsic rate of the SA Node, and what is another name for this? What ion drives the SA node?
Primary Pacemaker
- IR: 60-100 bpm
- Na driven
What is the intrinsic rate of the AV Node, and what is another name for this? What ion drives the AV node?
“Gatekeeper”
- IR: 40-60 bpm
- Ca driven
What is the intrinsic rate of the Purkinje fibers? When would this take over as pacemaker?
20-40 bpm
- Becomes pacemaker if SA & AV nodes fail
With resting state, what is the polar state is the cell in and what does this mean for ion movement?
Resting = Polarization
- NO net ion flow
With an action potential, what is the polar state is the cell in and what does this mean for ion movement?
AP = Depolarization
- Na enters cell and interior becomes positively charged
With repolarization, what does this mean for ion movement?
Na, Ca and K leave cell and interior returns to negatively charged resting state
What does bipolar lead mean, and what are the three bipolar leads?
Opposite polarity (- AND +) - Standard (I-III)
What does unipolar lead mean, and what are the nine unipolar leads?
ONLY +
- Chest/Precordial Leads (V1-V6)
- Augmented Limb Leads (aVR, aVL, aVF)
What part of the cardiac cycle does the P wave represent?
Atrial depolarization
What part of the cardiac cycle does the QRS complex represent? What other part is hidden in this complex?
Ventricular depolarization
- Also, atrial repolarization = hidden
What part of the cardiac cycle does the T wave represent?
Ventricular repolarization
What are the six LIMB leads, and what plane view do they make up? What is another name for this?
FRONTAL plane = Einthoven’s Triangle
- Standard (I-III)
- Augmented (aVR, aVL, aVF)
What are the six CHEST/Precordial leads, and what plane view do they make up?
HORIZONTAL plane
- V1-V6
Movement TOWARD ___ will appear ___ the baseline on the EKG pacing?
Toward positive electrode = ABOVE baseline
Movement AWAY from ___ will appear ___ the baseline on the EKG pacing?
Away from positive electrode = BELOW baseline
- Or toward negative electrode
