ElectroCardiogram Flashcards
Resting state, myocytes are POLARIZED, the inferior wall of every cell ________-ly charged.
NEGATIVE
Depolarized stimulates the heart myocytes, they become POSITVE and
_______.
CONTRACT
Phase when cell inferiors become positive
DEPOLARIZATION
Phase when cell interiors return to back to NEGATIVE
REPOLARIZATION
Refers to a positive electrode actively recording a patient’s EKG
Positive
Hearts dominant pacemaker
SA NODE (SINUS NODE)
Sinus rhythm
The ability of the SA NODE to generate pacemaking stimuli known as?
Automaticity
Wave on ECG recorded for atrial depolarization
Valves prevent ventricle to atrium blood back-flow and they electrically insulate the ventricles from the atria.
ATRIO-VENTRICULAR (AV) valves
Right side of the heart recieves under oxygenated VEVOUS blood from all over the body, and pumps it into the____?
LUNGS
The RV contracts, forcing the under-oxygenated venous blood through the pulmonary valve into the PULMONARY ___
ARTERY
LA contracts, forcing OXYGENATED blood through ____valve into the left ventricle.
MITRAL
muscular left ventricle contracts, forcing oxygenated blood through the ____into the aorta?
AORTIC VALVE
on EKG, Depolarization of the entire ventricular myocardium produces?
QRS complex
Wave is the first downward deflexion of the QRS complex
Q wave
Repolarization is accomplish by __ions leaving the myocytes
Potassium — K+
QT interval represents the duration of ventricular___ and is measured from the beginning of the QRS until the end of the T T wave.
SYSTOLE
Amount of time represented by the distance between TWO HEAVY BALCK LINES is
0.2 of a second
How many seconds, Each small divisions ( measured horizontally between fine lines) represents?
0.04 of a second
Four of the small squares represents___ of a second?
0.16
Hormones secretes by the terminal ends of SYMPATHETIC nerves that activates the ADRENERGIC receptors
Nor-epinephrine
Neurotransmitter secrete by the terminal PARASYMPATHETIC nerve ends, that activates cell RECEPTORS called CHOLINERGIC receptors.
ACRTYLCHOLINE
Receptors activates the heart in sympathetic system
Heart B1
Cardiac excitatory effects
( Sympathetic system)
Increase of SA Node pacing
Increase rate of conduction
Increase force of contraction
Irritability of FOCI
Receptors activates by Parasympathetoc system
CHOLINERGIC SYSTEM
Cardiac Inhibitory effects
Decrease all
Effects of VAGAL MANUEVERS
Parasympathetic reflex
—inhibits focus ( atrial or AV junctiona)
SVT convert to Sinus Rhythm
Inhibits AV node
Diagnostic aid
•With 2:1 AV block
• with atrial flutter
Type of hypotension secondary to abrupt fall in blood pressure caused by failure of these compensatory sympathetic mechanisms.
ORTHOSTATIC
Receptors are cardiovascular sensors
That the body uses to detect changes in BP
BARORECEPTORS
Impaired parasympathetic reflex in elderly due to inadequate peripheral vasoconstriction.
Neurocardiogenic syncope
Location of SA NODE
upper-posterior wall of RIGHT Atrium
Focal areas of Automaticity in the heart?
Automaticity foci
Potential pacemaker that are capable of pacing in the emergency situations
Node where the tail of the VECTOR
AV node
biphasic P wave seen on ECG
Atrial enlargement
P wave interval msec?
< 120 msecs
PR interval normal interval
< 200 msec
QRS duration normal interval?
< 110-120 msecs
Receptors activated by sympathetic system?
Adrenergic receptors
Cardiac B1
Receptor activates by Parasympathetic system
CHOLINERGIC
Neurotransmitter release by Parasympathetic nerves?
Acetylcholine (ACh)
Inhibitory
Neurotransmitter release by sympathetic system?
Norepinephrine
Activates the Heart B1
Stimulates the SA node
