ECG I- CardioRush

P wave
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Terms in this set (98)
P wave
What is 1?
Image: P wave
QRS complex
What is 2?
Image: QRS complex
T wave
What is 3?
Image: T wave
Atrial depolarization
What does the P wave represent?
Ventricular depolarization
What does the QRS complex represent?
Ventricular repolarization
What does the T wave represent?
SA node, AV node, bundle of His, bundle branches
What is the pathway that electrical impulses travel through?
2
How many bundle branches does the left ventricle have?
1
How many bundle branches does the right ventricle have?
Slower
What is conduction through the AV node compared to the SA node?
Allow time for ventricular filling before contractionWhy is conduction through the AV node slower than the SA node?Outside high in Na, low in K, inside high in K, low in NaWhat is the concentration of ions within and outside the cell at rest?KWhat ion is responsible for repolarization?CaWhat ion is critical to the function of the pacemaker cells?Phase 4 slowly moves towards threshold due to Ca leak channelsWhat is the shape of the AP in pacemaker cells?False (only in diseased states, the pacemaker cells possess it in normal states)True or false: Ventricular myocytes possess automaticity in normal statesPhase 4 spontaneous depolarizationWhat is responsible for the timing of the next beat on the AP?NaWhat ion initiates rapid depolarization in the cardiac myocytes?CaWhat ion is responsible for the contraction of cardiac myocytes?KWhat ion is used in the inward rectifier currents?Prolong the QT intervalWhy do Inward K Rectifier blocking drugs cause sudden death?SAWhat node usually controls the heart rate?TrueTrue or false: Alteration to slope of phase 4 of the AP changes heart rateIncreases HRWhat is the effect of increased SNS tone on heart rate?SA node, intranodal pathways, AV junctional tissue, purkinje fibersWhich myocardial tissues have the capacity for automaticity?Depolarizes fastest and fires firstWhy is the SA node in charge of setting the HR?Valves, pericardiumWhat are examples of cardiac structures that are do NOT possess the property of excitability?Purkinje fiber, Bundle of HisWhat is an example of a cardiac tissue with fast conduction velocity?AV nodeWhat is an example of a cardiac tissue with slow conduction velocity?InterferenceWhat is this an example of?Absolute refractory periodWhat is the term for the time of the AP when NO stimulus will cause another AP to be sent, no matter how great?Relative refractory periodWhat is the term for the time of the AP when a greater than normal stimulus will cause another AP to fire?Supernormal periodWhat is the term for the time of the AP when the heart fires more easily because it is less stable?FibrillationWhat happens if a stimulus hits the heart during the supernormal period?Arrhythmias may or may not be a problem, dysrhythmias are a problemHow are arrhythmias and dysrhythmias different?Signal jumps off by septum, travels linearly to get contraction from top to bottomWhat causes the shape of an ECG in type A species?Dog, cat, manWhat species are type A on an ECG?Extensive purkinje fiber activation very quicklyWhat causes the type B pattern on an ECG?Horse, ruminantsWhat species are type B?Premature beatWhat type of beat comes early and shortens the RR interval?Escape beatWhat type of beat comes after a long pause?Premature beatWhat is this an example of?Escape beatWhat is this an example of?Ectopic beatWhat is the term for an impulse that originates from anywhere except the SA node?Conduction blockWhat is the term for a pathologic delay or interruption of conduction?CouplingWhat is the term for a fixed relationship between a premature beat and the beat that precedes it?Yes (Premature beat has the same RR interval each time)Are these beats coupled?Compensatory pauseWhat is the term for when the pause during premature beat is equal to 2x the normal RR interval, so that the normal RR interval is maintained despite the premature beat?Non compensatory pauseWhat is the term for when the pause during the premature beat is less than 2x the normal RR interval, so that the RR interval is NOT maintained when the premature beat is present?Atrial premature beat, SA node resetWhat usually causes a non-compensatory pause?AV dissociationWhat is the term for independent depolarization of the atrial and ventricles?VPCWhat are fusion beats another manifestation of?Normally conducted impulse and VPC signal occur simultaneouslyWhat causes the formation of a fusion beat?J pointWhat is the term for the point where the QRS interval ends?J pointWhat is this point?Paroxysmal tachycardiaWhat is the term for tachycardia that has a sudden onset and abrupt end?Paroxysmal tachycardiaWhat is this an example of?Unifocal occurs when one area of the ventricle is diseased, multifocal occurs when disease is more widespreadWhat is the difference between unifocal or multifocal VPCs?FibrillationWhat is the term for completely chaotic activation of the atria or ventricles?FibrillationWhat is this an example of?Less COWhat is the result of atrial fibrillation?No CO, DeathWhat is the result of ventricular fibrillation?1mmOn ECG paper, what is the size of the smallest boxes?0.02 secHow much time is in 1mm in 50mm/sec paper?0.04How much time is in 1mm in 25mm/sec paper?P height and width, PR interval, QRS length, R height, ST segment, QT intervalWhat are the measurements we are interested in on a typical ECG?0.1mVWhat is the height of 1mm box indicate on standard 50mm/sec calibration?1cm=1mvWhat is standard calibration on an ECG?70-160What is the normal HR range for adult dogs?Normal sinus rhythm, sinus arrhythmia, wandering SA pacemakerWhat are the normal cardiac rhythms that can be seen in dogs?Current towards positive sideWhat is the direction of current in a lead if it causes positive deflection from baseline?Away from positive sideWhat is the direction of current in a lead if it causes negative deflection from baseline?Right lateral recumbency, limb leads just below elbows and kneesWhen we have "normal" values, what position is the animal in and where are the leads?TrueTrue or false: ECG leads placed too high on the chest or legs not being parallel to each other can cause artifactCount number of QRS in 3 seconds and multiply by 20 to get HR, or divide 3000 by number of boxes in the RR intervalWhat are the 2 ways to calculate HR on a 50mm/sec ECG?Number of QRS in 3 seconds times 20, or 1500 divided by number of boxes in RR intervalWhat are the 2 ways to calculate HR on 25mm/sec ECG?1, 2, 3, aVR, aVL, aVFWhat are the standard leads we use for a diagnostic ECG?Pos front left, neg front rightWhat is the positioning of leads in lead 1?Pos hind left, neg front rightWhat is the positioning of leads in lead 2?Pos hind left, neg front rightWhat is the positioning of leads in lead 3?Neg avg left, pos front rightWhat is the positioning of leads in lead aVR?Pos front left, neg avg front right hind leftWhat is the positioning of leads in lead aVL?Pos hind left, Neg avg frontWhat is the positioning of leads in lead aVF?Lead IIWhat lead is used most frequently for ECG?False (Only useful for that in small animal. In large animal, used for rate and rhythm)True or false: ECGs are useful to identify cardiac enlargement in horses and ruminantsBase-apex leadsWhat positioning of leads is most common in large animals?False (Can be used sometimes, just not as often as limb leads)True or false: chest leads are never indicated, only limb placementCan sometimes see P waves better, evaluate ST segment, detect ventricular enlargementWhat are the advantages of chest leads?False (Doesn't typically occur in adults)True or false: cardiac hyperplasia is a common cause of hypertrophy in adultsExercise, anemiaWhat are some physiologic stimuli for cardiac hypertrophy?Systemic hypertension, mitral valve regurg,What are some pathologic stimuli for cardiac hypertrophy?Wall stress, catecholamines, AT-II, aldosterone, hypoxia/ischemia, cytokinesWhat signals trigger cardiac hypertrophy?Concentric, eccentricWhat are the two types of cardiac hypertrophy?ConcentricWhat type of hypertrophy occurs in response to pressure overload?Systemic hypertension, aortic stenosisWhat are some examples of causes of pressure overload leading to concentric hypertrophy?EccentricWhat type of hypertrophy occurs in response to volume overload?Mitral regurg, ventricular septal defect, anemiaWhat are some examples of causes of eccentric hypertrophy?False (Some animals with marked hypertrophy can have normal ECGs, other tests are more sensitive)True or false: ECG is the gold standard for detecting cardiac hypertrophy in small animals