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67 Cards in this Set
- Front
- Back
- 3rd side (hint)
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What is unique about nodal cells? |
They spontaneously conduct an action potential |
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Explain the conduction system of the heart: |
SA node to AV node to bundle of His to left/right bundle branch to purkinje fibers |
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Why is there no direct electric impulse from the atrium to ventricle? |
Because there's fibrous tissue between them |
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Chronotropic effects are and associated with a ______ node. |
Measure the heart rate, SA |
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Dromotropic effects are and associated with the ______ node. |
Conduction velocity AV |
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Inotropic effects are: |
Force of contractility in the heart |
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Normal bpm: |
50-99 |
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An arrhythmia causes: |
Abnormalities in the impulse throwing the sinus off |
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Sinus tachycardia bpm: Sinus brachyrdia bpm: |
T: +100 B: 50-60 |
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Explain possible causes to supraventricular arrhythmia: |
Ectopic foci from atria or AV node producing an extra systole (contraction) in the ventricles throwing the sinus rhythm off |
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What is the P wave structure for atria extra systole and nodal extra systole? |
Atria: P wave is deformed Nodal: P wave is negative and masked by QRS complex |
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What occurs in ventricular extra systole? |
Ectopic foci produces an impulse distal to purkinje fibers; basically a heart beat is started from there instead of the SA node |
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The VPC is ____________ and the most common cause for ventricular ES. |
Ventricle premature complex |
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What occurs to the QRS complex of ventricular ES? |
It's deformed |
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Two mechanism of the VPC and what they're associated with: |
Automaticity, ischemic myocardium Reentry circuit: damaged myocardium, after an MI |
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Automaticity of VPC means: |
New depolarization site that's not non-nodular |
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Reentry circuit of VPC means: |
Slow connecting tissue adjacent to normal tissue |
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Treatment for ventricular ES: Two methods |
-Restoring magnesium, potassium and calcium in the body -pharmaceutical agents |
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Symptoms of ventricular ES: |
-retrosternal chest pain -faint feeling -fatigue -hyperventilation -ventricular tachycardia |
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What are the different type of pharmaceutical agents and examples: Class I Class II Class III Class IV |
Class I: Na channel blockers (lidocaine, phenytoin) Class II: beta blockers; reduce AV conduction; metrapolol, atenolol, propranolol Class III: K+ channel blockers; prolong repolarization: sotalol Class IV: Ca+ channel blockers; reduce AV conduction and retain heart rate; valapramil, diltiazem |
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What is the bpm for atrial tachycardia? |
100-250 |
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What occurs in ventricular tachycardia and its bpm? |
Ventricular filling and CO decrease; 100-250 bpm |
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If blood isn't ejected a ventricular tachycardia can get as dangerous as a _________________. |
Cardiac arrest |
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Which part of the EKG indicates AV node block? |
PR interval |
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What occurs in: 1st degree AV block 2nd degree AV block 3rd degree AV block |
1st: exceeds .2 sec 2nd: 2-4 atrial waves between ventricle 3rd: no atrial waves between ventricles |
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How much oxygen does myocardia cells absorb from the blood passing by? |
80% |
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_____ of myocardia cells is made up of mitochondria. |
1/3 |
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Other structures of myocardia cells: |
-tight junction -gap junction -myosin and actin -one nucleus |
4 |
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Factors that increase inotropic? |
-increases heart rate -beta-1 of sympathetic system -digitalis |
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What decrease inotropic factor? |
Parasympathetic system, muscarinic receptors |
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What is pre-load and how can it be described? |
Pre-load relates to right atrial pressure and is the amount of volume in the ventricle in relaxation phase; seen as the "stretch" due to the amount of blood volume that is created |
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Pre load = |
EDV |
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After load is seen as what? |
The squeeze of the ventricle and the amount of pressure needed to eject blood Equals aortic pressure Equals pulmonary pressure |
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Pre load = |
EDV |
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The velocity of contraction is maximum when after load is: |
Zero |
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When does velocity of contraction decrease? |
When after load increases |
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What are the steps in the cardiac cycle: |
Isovolumetric contraction Ventricular ejection period Isovolumetric relaxation Ventricular filling |
4 of them |
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What happens in isovolumetric contraction? |
Venous system fills right atrium with blood; pressure increases and is greater than ventricle; AV valve opens as blood flows into ventricle and 140 mL is present |
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EDV is: (number) |
140 mL |
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What happens in isovolumetric contraction? |
Venous system fills right atrium with blood; pressure increases and is greater than ventricle; AV valve opens as blood flows into ventricle and 140 mL is present |
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Ventricular ejection: |
Pressure increases in ventricle as aortic valve opens and 70 mL flows out to aorta, this is stroke volume |
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Isovolumetric relaxation: |
Great venous system flows blood into atria and it flows into ventricle, making it 140 mL again |
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Isovolumetric relaxation: |
Great venous system flows blood into atria and it flows into ventricle, making it 140 mL again |
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Formula for stroke volume, cardiac output, and ejection fraction: |
SV = EDV - ESV CO = SV/ HR Ejection fraction= stroke volume/ EDV |
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Isovolumetric relaxation: |
Great venous system flows blood into atria and it flows into ventricle, making it 140 mL again |
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Formula for stroke volume, cardiac output, and ejection fraction: |
SV = EDV - ESV CO = SV/ HR Ejection fraction= stroke volume/ EDV |
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Ejection fraction is usually _______. |
55% |
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What does cardiac oxygen consumption depend on? |
Tension created by ventricles |
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What factors increase cardiac O2 consumption: |
-increased: after load, heart size, contractility, heart rate |
Increased... |
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What pressure does the ventricle reach to eject blood into aorta: |
80 mmHg |
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What is cardiac output? |
The amount of blood pumped by each ventricle per minute |
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Resting bpm: |
70 |
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Normal cardiac output is: |
5 L/min |
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What is the CO of a normal person who exercises? |
20 L/min |
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What is the CO of an athlete who exercises? |
35-40L/min |
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Atherosclerosis is a inflammatory response to ________________ injury. |
Endothelial |
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What occurs in atherosclerosis? |
There is a build up atheromas (plaque) |
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What is the content of atheromas that builds up in the arteries? |
Ca deposit Lipid Inflammatory cells Connective tissue Smooth muscle cells Thrombi |
Six things |
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Possible causes of atherosclerosis? |
Dypsilipedemia, diabetes, obesity, family history, hypertension, smoking |
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Symptoms and complications of atherosclerosis: |
Symptoms: shortness of breath, tightness of chest Complications: stroke, damaged muscle, angina |
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What occurs in atrial flutter and fibrillation: |
Flutter: atrium beats faster than ventricle but is steady Fibrillation: beats faster than ventricle but is irregular as well |
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What occurs in atrial flutter and fibrillation: |
Flutter: atrium beats faster than ventricle but is steady Fibrillation: beats faster than ventricle but is irregular as well |
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Atrial ______________ can cause a blood clot. |
Fibrillation |
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Heart murmur is due to a _________ of blood flow. |
Turbulent |
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Heart murmur is due to a _________ of blood flow. |
Turbulent |
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Stenosis and regurgitation causes heart murmur how: |
Stenosis: valves are unable to open Regurgitation: valves are unable to close |
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Causes for atrial-fib and atrial flutter: |
Caffeine, tobacco, open heart surgery, dietary pills and stress and anxiety |
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