Term
| how does asymmetric ventricular hypertrophy affect the EKG's axis? |
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Definition
| more ventricular hypertrophy on one side pulls axis to that direction, (if right ventricular hypertrophy, will pull the axis to right) |
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Term
| what is the rate determination mnemonic for heart rate? |
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Definition
| 300, 150, 100, 75, 60, 50 |
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Term
| what is the "2 thumbs up" sign that is indicative of a normal axis? |
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Definition
| lead I (right to left) and aVF (down) which add up to 0-90 degreees |
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Term
| why is the left ventricle and septum thicker? |
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Definition
| that is the side which is going to pump blood out to the body, and the end point of depolarization |
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Term
| what will show in a L axis deviation in terms of lead I and aVF? |
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Definition
lead I = positive
aVF = negative |
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Term
| what will show in a normal EKG in terms of lead I and aVF? |
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Definition
|
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Term
| what will show in a R axis deviation in terms of lead I and aVF? |
|
Definition
lead I = negative
aVF = positive |
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Term
| what will show in an extreme R axis deviation in terms of lead I and aVF? |
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Definition
|
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Term
| can R ventricular hypertrophy cause a R axis shift? |
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Definition
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Term
| what are the 2 types of cardiac hypertrophy? why is hypertrophy generally problematic? |
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Definition
| eccentric (both ventricular wall thickness and chamber radius increase) or concentric (just wall thickness increases). in cases of hypertrophy, increased muscle mass means increased chance of hypoxia b/c oxygen has to diffuse across a greater distance |
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Term
| how is hypertrophy detectable with an EKG? |
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Definition
| the more myocytes producing a signal, the QRS will also read as larger. for example, a larger left ventricle can cause a L axis shift. P and T waves can start to appear abnormal on the precordial leads |
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Term
| what is the criteria for left ventricular hypertrophy (LVH)? |
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Definition
| if the amplitude of V1 and V5 QRS's is greater than 35 mm |
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|
Term
| what is the criteria for right ventricular hypertrophy (RVH)? |
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Definition
| if there is an upright R wave in V1 (consider R ventricular hypertrophy) |
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Term
| if a pt comes in with chest pain and MI what needs to take place? |
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Definition
| thrombolytics, catheter into the coronary of interested, or bypass. if vessels become occluded b/c of clot/spasms/etc - ischemia will occur, (heart still working, using up O2, using mitochondria, membrane pumps are screwed up b/c no new ATP - Na starts to accumulate in cells and water comes in = cells burst) |
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Term
| when is the time of greatest blood flow into the coronary arteries? |
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Definition
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|
Term
| what enzymes are released during an MI? |
|
Definition
| myoglobin, CPK, and troponin |
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Term
| what happens during an MI to SV? what compensates for this? what can this lead to? |
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Definition
| SV will decrease (due to loss of heart muscle), and HR increases to compensate which can leads to pain and possibly ventricular fibrillation (if conduction is messed up enough) |
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Term
| what does it mean if the S-T segment in leads II, III, and aVF are elevated? |
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Definition
| interior infarct (from below) - possibly due to a R coronary occlusion |
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Term
|
Definition
| if lead I and aVL are messed up |
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|
Term
|
Definition
| S-T elevation, indicative of an MI or an impending one |
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Term
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Definition
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|
Term
| what is the cascade of events when an MI occurs? |
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Definition
| the low SV due to muscle death, will give a low CO - sympathetics will try to raise CO with increased TPR, but this increases the afterload - making the already damaged heart work harder (sweating is an indication of this) |
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Term
| how does sinus tachycardia appear on an EKG? |
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Definition
| rate: greater than/equal to 100, rhythm: regular, P waves: upright, consistent, normal in morphology |
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Term
| how does a R ventricular MI appear on an EKG? |
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Definition
| no R wave progression, the R waves are negative b/c the signal is blocked and the quick positive charges are going away from the precordial leads |
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Term
| what is seen in the instance of an acute septal MI? |
|
Definition
| elevated S-T segments in the precordial leads around the septum: V1-3 |
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|
Term
| what do changes in V3 and V4 indicate? |
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Definition
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|
Term
| what is likely with S-T segment depression? |
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Definition
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|
Term
| what is it called when the atrial rate is 2x the ventricular rate? |
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Definition
|
|
Term
| what is a sign on an EKG of digitalis toxicity? |
|
Definition
| scooped waves and bradycardia |
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|
Term
| what is a dual chamber pacemaker? |
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Definition
| one that activates both the atria and the ventricles |
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|
Term
| to read an EKG, what must you be able to determine? |
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Definition
| rate, rhythm, axis, hypertrophy, ischemia, and infarction |
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|
Term
| what is indicative of ischemia? |
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Definition
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Term
| what is hyperkalemia? how does it appear on an EKG? how can this be treated? |
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Definition
| hyperkalemia = high K+ (7-9), which leads to depolarization, causing the EKG to eventually look like a sine wave due to *increased amplitude of the T waves. the QRS will also widen, and the EKG may resemble ventricular tachycardia. extracellular K+ will follow glucose or insulin intracellularly if administered. bicarb can also drive the K+ intracellularly. (this can be caused by renal failure or too high K+ intake) |
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|
Term
| what is characteristic of hypokalemia? |
|
Definition
| U waves after the T waves, b/c low K+ (<3)affects membrane potential. |
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|
Term
| how does L atrial enlargement manifest itself on an EKG? |
|
Definition
| the P waves are elongated and bi-phasic (notched) |
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|
Term
| what is seen on an EKG in terms of LVH? |
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Definition
| tall R waves in LV leads, widened QRS/T angle, and a leftward shift in the frontal plane QRS axis. sinus tachycardia may also be seen. |
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Term
| how does a L bundle branch block appear on an EKG? |
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Definition
| the QRS's are widening (due to the bundle branch block - the action potentials are spreading) |
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Term
| how does pericarditis manifest itself on an EKG? |
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Definition
| tachycardia, lots of elevated S-T segmemnts (appears like an MI) - but there is also P-R interval depression in the precordial leads |
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|
Term
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Definition
| PAC - premature atrial contraction, where the QRS fires too soon after the last T wave. a PVC is a premature ventricular contraction, where the ventricles fire early - wide QRS |
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Term
| what is the danger with prolonged Q-T intervals? |
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Definition
| if there is a premature atrial contraction, this could send the person into ventricular fibrillation -> death |
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