Term
| myocardial infarction presentation and finding |
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Definition
| most present w classic chest pain and have ST elevation and pathalogic Q waves but 25% do not present w classic signs and 50% have nondiagnostic EKGs (why we need cardiac markers) |
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Term
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Definition
| myoglobin (lowest molecular weight so released by cells 1st, detect within 1st 1-4 hrs peaks at 12 hrs cleared at 24 hrs, also present in other skeletal muscle and smooth muscle tissue), creatine kinase (released when cells are damaged, transfers phosphate between creatine phosphate and ADP, found in muscle, brain, heart, MM- skeletal muscle, MB- heart, BB- brain, also used for rhabdomyolosis or stroke/seizure, total CK and CK-MB ratio at 4-6hrs post injury ratio >4 is high suspicion for MI) ,CRP, BNP, troponin (protein complex that regulates the contraction of striated muscle, C-skeletal muscle, T and I- heart muscle, released 3 hrs post MI and peaks 24-48 hrs, remains elevated 2 weeks, in unstable angina troponin elevation is a risk factor for future ischemic events), troponin and CK-MB can be used to assess extent of damage but coronary angiography or echo may be better |
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Term
| steps if person has symptoms of MI |
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Definition
| EKG, then CK troponin and myoglobin, for management of ST elevation- get CBC w plt count, INR and PT, PTT, electrolytes, BUN and creatinine, glucose, serum lipids. to look for risk factors for coronary artery disease |
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Term
| what is congestive heart failure |
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Definition
| where the heart is unable to pump enough blood to meet tissue demands, can't perfuse tissues adequately or take away waste products. can be due to MI, atrial fibrillation, hypertension, sepsis, endocarditis, embolisms, certain medications (doxorubicin chemo agent) |
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Term
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Definition
| BNP- hormone released from ventricle myocytes in response to high atrial and ventricular filling pressures (inc pressures bc trying to make heart a better pump), not specific for CHF, indicated fluid overload and hemodynamic stress. BNP >100 is consistent w heart failure. can be useful to r/o heart failure so you don't have to do invasive tests like a cardiac echo. also elevated in renal failure and elevated serum creatinine, . CRP can also be elevated due to inflammation w CHF, it's an acute phase reactant that elevates in less than 2 hrs, very nonspecific. hs-CRP is a marker for low-level inflammation in arterial disease/future cardiovascular risk prediction, <1 = low risk >3 = high risk |
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Term
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Definition
| pacemaker cells- set HR + create their own action potentials, electrical conducting cells, myocardial cells (trigger contraction) |
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Term
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Definition
| predominant pacemaker of the heart, firing rate of 60-100 beats per min. it depressed other cells in heart can also set HR but aren't as fast- AV node |
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Term
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Definition
| cells in the ventricle that drive the HR in the ventricle, small delay to allow ventricles to fill |
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Term
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Definition
| may compete w SA node for control of HR |
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Term
| electrical conducting cells |
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Definition
| long thin cells that make up the electrical wiring in the heart, carry stimulus from atrium and SA node -> AV node -> ventricles -> bundle of His -> R or L branch -> perkinje fibers -> distributes impulse to myocardial muscle cells |
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Term
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Definition
| paper moves 25mm/sec. vertical axis is voltage. horizonal axis is time. each small box is 0.1mV. One big box is 0.20 sec. Each little box is 0.04 sec. |
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Term
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Definition
| atrial depolarization, 1st part in right atrium, 2nd part in left atrium |
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Term
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Definition
| distance from beginning of P wave to beginning of QRS complex. time it takes the impulse to travel from the SA node to the AV node and entering the ventricle, good estimate of AV node function (long delays is something blocking transition from AV node to ventricle, could be heart block), always use the shortest PR interval, it can vary. normal is 0.12 sec - 0.20 sec |
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Term
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Definition
| beginning to end of QRS complex, depolarization of the ventricles, usually <0.12 sec or less than 3 boxes |
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Term
| what can widen the QRS interval |
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Definition
| (conduction delay bc this is going through the bundle of his), will slow down if one ventricle is hypertrophied, or if the impulse is starting in the ventricle there is a delay |
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Term
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Definition
| if neg is a Q wave, if pos is an R wave |
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Term
| 1st downward deflection after an upward deflection |
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Definition
| S wave (additional upward or downward defections are S' |
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Term
| smaller waves designated as |
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Definition
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Term
| if only 1 negative deflection |
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Definition
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Term
| if no deflection above baseline |
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Definition
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Term
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Definition
| between QRS complex and beginning of T wave, normally isoelectric/back to baseline, impt for MIs |
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Term
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Definition
| junction at end of QRS complex and beginning of T wave. J point depression can be noted during a stress test put is normal |
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Term
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Definition
| large delta wave following a QRS or a small secondary R wave, has a slow down stroke, can be seen in Wolff-Parkinson-White syndrome, hypercalcemia, hypothermic pts |
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Term
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Definition
| repolarization of the ventricle. slow rise and rapid return to baseline. |
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Term
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Definition
| after T wave but not in everyone. represent the later phase of ventricular repolarization, possibly of the ventricular septum, noted in severe hypokalemia, hypocalcemia, hyperthyroidism, but can be normal in some pts |
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Term
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Definition
| beginning of Q wave, through the T wave, varies w HR, can be inc or dec w drugs or metabolic issues, usually <0.45 sec, some drugs can prolong the QT interval and lead to arrhythmias, in pts w normal prolonged QT interval would want to avoid ketoconazole, erythromycin, clarithromycin |
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Term
| calculating a regular HR from an EKG |
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Definition
| count number of boxes between 2 QRS complexes then divide out of 300 |
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Term
| calculating an irregular HR from an EKG |
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Definition
| you can average between QRS complexes or use a quicker method: larger boxes to the right of the QRS complex/R wave follow the pattern of 300, 150, 75, 60, 50, 40, 30, 15 for each big box to the right (small boxes between the big boxes have diff values for each segment) |
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Term
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Definition
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Term
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Definition
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Term
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Definition
| left arm is pos, right arm is neg, neg-> pos, vector angle 0 |
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Term
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Definition
| left leg pos, right arm is neg, 60deg, standard lead, predominantly pos, axis of heart, QRS is pos, P wave is pos, t wave is pos |
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Term
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Definition
| left leg is pos, right arm is neg, 120 deg |
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Term
| leads 1, 2 and 3 together |
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Definition
| these are bipolar leads bc made up of two leads. together make up einthoven's triangle where the heart is in the center of the extremities |
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Term
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Definition
| augmented, unipolar leads that record voltage at one location relative to 0. record the diff between positive extremity and electrical center of the heart |
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Term
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Definition
| rt arm is pos, waveform usually neg, most currents on EKG below baseline, neg 150 deg |
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Term
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Definition
| legs are pos, looks at inferior portion of the heart (also look at leads 2 and 3 for this) |
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Term
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Definition
| left arm is pos, looks at lateral portion of the heart, 30 deg |
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Term
| if you add a lot of muscle mass to left side of heart vs right side |
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Definition
| if left side gets bigger, electrical current will shift towards the left, get left axis deviation. if rt side gets bigger get right axis deviation |
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Term
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Definition
| V1 is on chest on right side of heart -4th intercostal space on right sternal border (look at this for right heart hypertrophy), V6 is at the apex of the heart at the bottom (look at left ventricle) is midaxillary and at level of v4. different locations can help determine where damage is occuring in heart |
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Term
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Definition
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Term
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Definition
| disturbance in rate, regularity, site of origin, or conduction of the impulse, look at lead 2 rhythm strip |
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Term
| what can cause bradycardia |
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Definition
| runner (50s), drugs (beta blockers, calcium channel blockers), inc vagal tone, hypothyroidism, hyperkalemia, inferior wall wall MI, carotid massage |
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Term
| what can cause tachycardia |
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Definition
| anxiety, fever (up 10bpm per degree F), infection, drugs (epinephrine, dopamine, cocaine, tricyclic antidepressants, anticholinergics), PE, MI, hyperthyroidism, |
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Term
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Definition
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Term
| inspiration vs expiration |
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Definition
| inspiration will accelerate HR, expiration will dec (changes in vagal tone) |
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Term
| p wave in lead 2 vs AVR and AVL |
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Definition
| upward in lead 2, downward in AVR, smallest in AVL |
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Term
| normal vs pathological Q wave |
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Definition
| less than 1 box wide or less than 1 box deep is normal, too deep or wide is positive deflection /pathological Q wave and can indicate old MI |
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Term
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Definition
| ratio of R wave to S wave is 1 (can change with infarct or loss of tissue) |
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Term
| too much depression or elevation of ST segment |
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Definition
| worry about ischemia or infarct of heart |
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Term
| normal t wave progression |
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Definition
| slow then fast return to baseline, generally follows direction of QRS complex. always pos in lead 2, always neg in aVR. if T wave is pos in any chest lead, should be pos in all chest leads to the left of it, height should be less tahn 5mm in extremity leads and less than 10 mm in chest leads |
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Term
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Definition
| <.45 sec of 50% of R to R interval |
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