Term
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Definition
| Method of tracing the electric current genterated by the heart muscle during a heartbeat. |
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Term
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Definition
1.Monitor Heart Rate.
2.Assess the effects of injury or disease on cardiac function.
3.Assess pacemaker function.
4.Gives a baseline for cardiac function.
5.Tells us the orientation of the heart within the chest.
6.Detects the presence of ischemic changes with in the heart muscle. |
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Definition
| The ability for the heart to adequately supply the body with oxygenated blood. |
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Definition
| Helps the heart stay in rhythm when the heart cannot do it on its own. |
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Definition
| The repeated pumping process of the heart, and includes all the events associated with the flow of blood through the heart. |
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Term
| Two Phases of the Cardiac Cycle |
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Definition
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Term
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Definition
| The period during which a chamber contracts and blood is forced out. |
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Definition
| The period which a chamber relaxes and fills with blood. The Myocardium receives blood in diastole. |
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Definition
Is when the blood is ejected out of the heart and to the organs.
Left ventricle to the body.
Right ventricle to the lungs. |
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Definition
| Blood enters the ventricles through the atrioventricular valves as the ventricles are relaxing. |
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Definition
| Blood is ejected from the atria into the ventricles. |
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Definition
| Blood enters the atria and fills while the atria are relaxed. |
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Definition
Atrial systole occurs during ventricular diastole.
Atrial diastole occurs during ventricular systole. |
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Term
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Definition
The # of beats per minute (BPM).
60-100 BPM
Heart rate is influenced by the autonomic nervous system. |
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Term
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Definition
Fight or flight. Prepares the body to function under stressful situations.
Norepinepherine: Increases heart rate, blood pressure and force of contracion. |
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Term
| Parasympathetic Stimulation |
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Definition
| Rest & Digest. Conserves and restores the bodies resources. Acetylcholine:Decreases rate of discharge from the SA node, rate of conduction through the AV Node, strength of atrial contraction. May generate a small increase in ventricular contraction. |
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Term
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Definition
| Located in the internal carotid atery and aortic arch. Detects changes in arterial blood pressure. Cause change through the autonomic nervous system. |
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Term
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Definition
| Located in the ICA and aortic arch. Detects changes in the concentration of oygen and CO2 and the changes in pH of the blood. Cause change through the autonomic nervous system. |
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Term
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Definition
| Return of blood to the heart from the systemic circulation via the IVC,SVC and coronary sinus. Most significant factor determining the amount of blood pumped out of the heart. |
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Term
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Definition
| Amount of blood pumped out of the heart per minute. Normal CO for an adult is 4-8 L/min. CO=HR*SV |
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Term
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Definition
| The amount of blood forced out of the ventricle with one contraction (heartbeat). |
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Term
| Determinants of Stroke Volume |
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Definition
1.Preload
2.Afterload
3.The myocardium's contractile state(relaxed or contracted). |
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Definition
| The force exerted on the walls at the end of diastole. Amount of blood that enters the ventricles during relaxation. Venous return up-Preload up. |
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Definition
| The pressure against which the ventricle must pump. Determined by arterial blood pressure. The ability of arteries to stretch. |
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Definition
The force exerted on the arterial walls
by the circulating blood volume. Depends on: Heart's contraction, viscosity of blood,resistance to flow, volume of blood and elasticity of walls. |
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Term
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Definition
BP=Cardiac Output*Peripheral Resistance
120/80 Normal Adult. |
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Term
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Definition
| The more blood that enters the ventricle during diastole, the more blood will be ejected during systole to a certain point. |
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Term
| Mechanical Function of Cardiac Cells |
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Definition
| Myocardial cells have contractille filament,when stimulated contract. |
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Term
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Definition
| Provides the stimulus to contract the myocardial cells. |
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Term
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Definition
| 5 phase cycle that reflects the difference in concentration of electrolytes across a cell membrane. |
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Term
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Definition
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Term
| 5 Phases of Cardiac Action Potential |
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Definition
Phase 0:Rapid Depolarization-contraction. Na+ in.
Phase 1:Inactivation of the Na+ channels.
Phase 2:Plateau Phase, Ca+ in,K+ out.
Phase 3:Rapid Repolarization-relaxation.
Phase 4:Resting membrane potential. |
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Term
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Definition
| The inside of the cell is more negatively charged than the outside of the cell when at rest. Called a membrane potential. |
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Definition
| Cell lets Na+ in, pacemaker can create an electrical impulse. Normally begins in the SA node. Displayed as an upward spike on the ECG tracing. |
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Term
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Definition
| Travels down conduction system to myocardial cells causing them to contract. Thus heart contracts. |
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Term
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Definition
| K+ out. Cells rapidly begin to return to their normal negative charge. Starts in the epicardium and travels to the endocardium. Relaxation. |
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Term
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Definition
| The amount of time required for a cell membrane to be ready for the next stimulus after it has been excited. In the myocardium it is longer than the actual contraction. |
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Term
| Absolute Refractory Period |
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Definition
| Cell will not respond to stimulus. |
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Term
| Relative Refractory Period |
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Definition
| Some cells have depolarized, and can respond to a strong stimuli. |
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Term
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Definition
| Occurs after the Relative Refractory Period, and weaker than normal impulses can cause depolarization. Arrhythmias can arise here. |
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Term
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Definition
Sinoatrial(SA)Node,Atrioventricular (AV)Node,Bundle of His,Bundle Branches,
Purkinje Fibers, Myocardial Cells. |
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Term
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Definition
| The pacemaker. Upper wall of right atrium, near SVC. Generates heart's rhythm. Starts impulse in both atria. 60-100 BPM |
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Term
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Definition
Between atria and ventricles. Delays impulse to allow atria to empty.
40-60 BPM. |
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Term
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Definition
Located in superior portion of septum.
Allows coordinated contraction of ventricles. |
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Term
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Definition
10 electrodes:12 Leads
A lead shows us the elecctrical activity between two electrodes. |
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Term
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Definition
Right Arm: White
Left Arm: Black
Right Leg: Green
Left Leg: Red |
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Term
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Definition
All limb leads are bipolar (+,-)
Lead + - View
I Left Arm Rt Arm Lateral
II Left Leg Rt Arm Inferior
III Left Leg Lt Arm Inferior |
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Term
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Definition
| An imaginary equilateral triangle with corners at the right shoulder,left shoulder and pubic region. The sides are leads I,II,& III. |
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Term
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Definition
All chest leads are unipolar (+).
Lead Location View
V1 4th IC Right Septum
V2 4th IC Left Septum
V3 Mid V2 and V4 Anterior Surface
V4 5th IC MidClav Anterior Surface
V5 Ant Axillary,V4 Lateral Surface
V6 Mid Axillary,V4/V5 Lateral Surface |
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Term
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Definition
Unipolar Limb Leads, heart is neg. pole
Lead + View
aVR Rt Arm Base of Heart
aVL Lt Arm Lateral Surface
aVF Lt Leg Interior Surface |
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Term
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Definition
Small Box: 0.04 sec
Large Box: 0.2 sec (5 small boxes)
5 Large Boxes: 1 sec |
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Term
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Definition
| Depolarization of Atria. 1st "bump" on an normal ECG. No more than 2.5mm(.25mv) in amplitude. No more than .11 sec. |
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Term
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Definition
Time from SA Node to AV Node.
Start of P wave to start of QRS complex
0.12-0.20 sec in duration. |
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Term
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Definition
Depolarization(contraction) of ventricles. Narrow,high amplitude.
Normal adult .06-.10 sec for complex.
Q-wave 1/3 amplitude & less than .04 sec. |
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Term
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Definition
Time following depolarization of ventricles. Immediately prior to repolarization of the ventricles.
From end of QRS to start of T-wave. |
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Term
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Definition
Repolarization of the ventricles.
Normally positive.
Same direction as QRS complex. |
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Term
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Definition
| Total duration of the electrical activity of the ventricles. Depolarization & repolarization. Measured from start of QRS to end of the T-Wave. 0.33-0.44 sec. |
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Term
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Definition
| Baseline. Area of no electrical activity. |
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Term
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Definition
| Not always seen. Small upright wave after the T-wave. Thought to be the repolarization of the Purkinje fibers or papillary muscles. Seen in hyperkalemia. |
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Term
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Definition
| Distortion of the waveform due to electrical interference. Caused by:Loose electrodes,Patient movement, 60 cycle interference. Isoelectric line is fuzzy. |
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Term
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Definition
1.6 sec. count
2.Count Large Squares
3.Count Small Squares
4.Sequence Method |
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Term
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Definition
| Count the number of QRS complexes in a 6 sec. period, multiply by 10. |
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Term
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Definition
| Count the number of large squares between two QRS complexes. Divide 300 by that number. |
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Term
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Definition
| Count the numbers of small boxes between two QRS complexes. Divide 1500 by that number. |
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Term
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Definition
| Select an R wave that falls on a dark line. Number the next 6 dark lines:300,150,100,75,60,50. The rate is where the next R-wave falls. |
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Term
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Definition
| Measure several points on the rhythm strip to evaluate if the rhythm is regular or irregular. Regular, Regularly Irregular, Irregularly Irregular. |
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Term
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Definition
| Distance between two consecutive R-Waves, R-R Interval. Compare to other R-R Intervals. |
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Term
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Definition
| Distance between two consecutive P-Waves, P-P Interval. Compare to other P-P Intervals. |
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Term
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Definition
1.Tall P-wave:Can indicate Right Atrial Enlargement,aka:P-Pulmonale.
2.Bifid:2 bumps,wide P-wave, Left Atrial Enlargement,aka:P-Mitrale
3.Inverted/Absent:Rhythm originated within the AV-junction or the ventricles. |
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Term
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Definition
1.Shortening: Accessory pathway,skips Av Node right to ventricles.
2.Lengthening: >.20 sec, AV Nodal Block,delay of impulse from ischemia,
toxicity,fibrosis. |
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Term
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Definition
| More than 1/3 of QRS means pathology: MI or Ischemia, could be old or new. |
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Term
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Definition
| An additional positive deflection in the R wave. |
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Term
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Definition
| Additional negative deflections in the S wave. |
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Term
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Definition
1.Increased amplitude(height): Ventricular Hypertrophy.
2.Wide: Slow conduction,ectopic electrical pacemaker. |
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Term
| Mechanical vs. Electrical |
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Definition
| The mechanical events happen slightly after the electrical events. |
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Term
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Definition
1.Prolonged: >.5 Long QT syndrome
2.Short:<.3 Short QT syndrome
Congenital Cardiac Abnormalities
Leads to Syncope. |
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Term
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Definition
| ST elevation or depression may be normal or may be ischemia/MI. |
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Term
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Definition
1.Inverted:Ischemia,Tension pneumothroax, Digitalsis toxicity, CNS disturbance.
2.Tall: Hyperkalemia
3.Flat:Hypokalemia |
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Term
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Definition
NSR: Rate
Regular Sinus Rhythm:Reg. vs. Irreg.
60-100 BPm, everything normal. |
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Term
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Definition
Less than 60 BPM
Severe: Less than 40 BPM
QT Interval may be longer. Caused by MI, sleep, meds etc. Help with Beta Blockers. |
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Term
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Definition
Greater than 100 BPM
In adults:101-180 BPM
Infants:>200 BPM
Child:>5, rate >160 BPM Caused by fever, pain, anterior MI, exercise. |
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Term
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Definition
SA Node fires irreg.(irreg. rhythm)
1.Respiratory Sinus Arrhythimia:breath
2.Non Respiratiry Sinus Arrhythimia: Meds or Heart Disease (inferior MI). Atropine can help. |
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Term
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Definition
Aka: SA Block, Sinus Exit Block.
Impulse blocked as it exits the SA Node. No QRS Complex. Irreg.(skipped) rhythm. MI and Meds, may need pacemaker. |
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Term
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Definition
| When the SA Node doesn't make the impulse. AV or ventricles may take over. Hypoxia, MI, Hyperkalemia, Digitalis Toxicity. > 3 sec or compromising hemodynamics then pacemaker. |
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