Term
| Atrial enlargement is produced by |
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Definition
| increased atrial work or volume overload. |
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Term
| Ventricular enlargement is caused by |
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Definition
| clinical conditions that increase the workload of the ventricle or volume overload. |
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Term
| Right atrial enlargement (RAE) |
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Definition
–Tall peaked P waves (P pulmonale)
–>2.5mm in inferior leads
–Tall initial upstroke of the P wave in V1 and a terminal negative deflection
–Width remains normal |
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Term
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Definition
–Notched or M shaped P wave in leads I, II, aVL (P mitrale)
–Small initial upstroke of the P wave in V1 with a deep terminal negative deflection
–P wave width of 0.11 seconds |
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Term
| •Right Ventricular Enlargement |
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Definition
–Right axis deviation
–R wave in V1 exceeds the depth of the S wave
–R wave in V1 is >7mm and >5mm in aVR
–Delayed intrinsicoid deflection
–RSR’ pattern in lead V1
–QRS width 0.10 seconds
–Reversed R wave progression in V1-V6 |
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Term
| •Left Ventricular Enlargement |
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Definition
–Left axis deviation
–R wave voltage >11mm in lead I and aVL
–R wave voltage >26mm in lead V5-V6
–Height of the R wave in V5-V6 plus the depth of the S wave in V1 > 35mm
–QRS is prolonged and increases in amplitude
–R wave grows taller |
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Term
| Right Bundle Branch Block (RBBB) |
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Definition
–Conduction system delay through the right bundle branch of the ventricular conduction system
–QRS >0.12 seconds
–RSR’ pattern with final R in V1
–QRS pattern with final wide S in V6
–Right chest lead will show T wave inversion
–Complete RBBB, QRS >0.12 seconds
–Incomplete RBBB, QRS 0.10 to 0.12 seconds |
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Term
| •Left Bundle Branch Block (LBBB) |
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Definition
–QS pattern > 0.12 seconds in V1
–Wide tall R wave in V6
–Septal depolarization is right to left |
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Term
| •Turn signal method of bundle branch block determination |
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Definition
-Works only in lead V1
-Go to the J point at the end of the QRS
-Draw a straight line over to the QRS complex
-Fill in this triangle and observe the direction it points
-This correlates with the motion you would make to indicate the direction you want to turn while driving your car
-Triangle points up : turn right (RBBB)
-Triangle points down: turn left (LBBB) |
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Term
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Definition
•Branch of the LBBB
•Mean QRS axis of -45 degrees or more (left axis deviation)
•S wave in aVF equals or exceeds the R wave in lead I
•Deep S wave in lead II
•Basically: LAD + negative QRS in lead II
•QRS usually <0.12 seconds |
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Term
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Definition
•Posterior branch of the LBBB
•Mean QRS axis of +120 or greater (right axis deviation)
•Tall R wave in lead II
•Basically: RAD + tall R wave in lead II
•QRS < 0.12 seconds
•Rule out RVH |
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Term
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Definition
•Represents an abnormal direction of ventricular depolarization
•Determination of axis is obtained by overlapping the standard and augmented limb leads |
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Term
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Definition
•Use lead I and aVF
•Normal axis, + lead I, + aVF
•Left axis, + lead I, -aVF
•Right axis, -lead I, +aVF
•Extreme right axis, -lead I and aVF |
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Term
| Precise Axis Determination |
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Definition
•Find the most biphasic limb lead.
•The axis will be 90 from the biphasic limb lead. |
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Term
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Definition
•Decreased blood flow to the myocardium.
•T wave depressed or flattened.
•T wave inversion in leads V1 through V6 is considered pathological.
•ST segment elevation indicates myocardial injury.
•ST segment elevation alone represents small infarction.
•ST elevation with Q waves represents large infarcted area.
•ST elevation concaved in shape throughout all chest and limb leads suggest pericarditis. |
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Term
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Definition
•Death of the myocardial muscle due to prolonged lack of oxygen.
•Q wave in leads II, III, aVF with ST elevation or depression indicates inferior infarction.
•Q waves in leads V1, V2, V3, V4 indicates anterior wall infarction.
•Q waves in leads I, aVL, V5, V6 indicates lateral wall infarction.
•Large R wave in V1, V2, and Q wave in V6 with ST depression in V1–V3 indicates posterior wall infarction. |
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Term
| •Digitalis Effect At Normal Therapeutic Levels |
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Definition
•Shortened ventricular depolarization and repolarization time
•Shortened QT interval
•Scooping of the ST-T complex (characteristic finding) |
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Term
| •Digitalis Toxicity – EKG Findings- |
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Definition
•Sinus bradycardia
•Sinoatrial block
•Atrioventricular blocks
•Ventricular tachycardia (including bidirectional ventricular tachycardia)
•Torsades de pointes
•Ventricular fibrillation |
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Term
| Quinidine and Procainamide Effects |
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Definition
•Prolonged ventricular repolarization
•Wide QRS
•Prolonged QT interval
•Torsades de pointes and Ventricular Tachycardia |
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Term
| •Tricyclic Antidepressants. |
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Definition
•Three Major EKG Criteria
•Sinus tachycardia
–Due to anticholinergic and adrenergic effects
–May persist for several days post exposure
•QRS complex prolongation
–From slowed ventricular conduction
•QT interval prolongation
–From delayed repolarization |
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Term
| •Hyperkalemia (>5.5 mEq/L)- |
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Definition
•Tented tall T waves
•AV block
•Flattened P waves and long PR interval
•Slow ventricular conduction (wide QRS) |
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Term
| •Hyperkalemia (>9.0 mEq/L) – |
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Definition
•Loss of P waves
•Wide QRS (to the point of looking like a “Z”)
•Sine waves
•Ventricular fibrillation leading to death |
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Term
| •Hypokalemia (<3.5 mEq/L) – |
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Definition
•U waves prominent
•Ventricular ectopy
•Ventricular tachycardia |
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Term
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Definition
–Prolonged PR interval
–Shortened QT interval and ST segment
–Ventricular arrhythmias may occur if severe imbalance
–Increased risk for digitalis toxicity |
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Term
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Definition
–QT prolongation with increased risk for arrhythmias (torsades de pointes)
–Prolonged ST segment, normal T wave morphology |
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Term
| •Hypermagnesemia (>2.5 mEq/L) |
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Definition
•Prolonged PR interval
•Widened QRS complex
•Tall T waves
•Atrioventricular block
•Cardiac arrest |
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Term
| •Hypomagnesemia (<1.5 mEq/L) |
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Definition
•Prolonged QT and PR interval
•ST segment depression
•Premature ventricular complexes (warning signs!!)
•Torsades de pointes |
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Term
Effects of Cardiovascular Disease States
•Mitral Stenosis |
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Definition
•Reduced opening of mitral valve due to calcification or fusing of cusps from rheumatic heart disease
•Results in back-up of pressure into LA and into pulmonary vasculature, eventually into right heart
•ECG changes include concomitant presentation of LAE and RVH |
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Term
Effects of Cardiovascular Disease States
•Pulmonary Embolism |
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Definition
•The ECG is not a sensitive test for pulmonary embolism
•ECG changes are usually indirect reflections of pulmonary arterial obstruction: |
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Term
| •Pulmonary Embolism EKG Criteria |
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Definition
•Sinus tachycardia
•Atrial fibrillation possible
•Premature ventricular complexes possible
•RV strain pattern (inverted T waves in V1-V4)
•SIQIIIT-inversionIII (S wave in I, Q wave in III, and T wave inversion in III, due to acute RV dilation)
•Shifting of mean QRS axis towards RAD
•ST depression indicative of subendocardial ischemia
•Incomplete or complete RBBB |
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Term
| Analyze the following features on every ECG: |
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Definition
•Heart rate
•P wave
•Origin of the rhythm
•PR interval
•QRS duration
•QT interval
•QRS axis
•QRS voltage
•Precordial R wave progression
•Abnormal Q waves
•ST segment
•T wave
•U wave
•Electronic pacemaker evaluation |
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Term
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Definition
•Single stimulus (beat)
•Appear earlier in the cycle
•Atrial, junctional, or ventricular foci become irritable |
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Term
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Definition
•Rapid rhythms originating in very irritable automaticity foci
•Defined by rate, range, and origin |
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Term
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Definition
•Sinoatrial (SA) node
•SA block
•Misses one pacing stimulus
•Sufficient pause |
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Term
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Definition
•Leads are V1–V6.
•Record electrical voltages transmitted onto the horizontal plane of the body (a plane dividing the body into upper and lower halves).
•Record electrical voltages directed anteriorly, posteriorly, and to the right and left |
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Term
| Augmented Limb (Extremity) Leads |
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Definition
•The voltages recorded at each extremity are electronically augmented by 50% by the electrocardiograph.
–aVR (augmented Voltage, Right arm)
–aVL (augmented Voltage, Left arm)
–aVF (augmented Voltage, Left Foot) |
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Term
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Definition
–Records the difference in voltage between left leg (LL) and left arm (LA) electrodes (Lead III = LL minus LA)
–Points downward. Lower pole (LL) is positive and its upper pole (LA) is negative
–Einthoven’s triangle: graphic representation of standard limb leads |
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Term
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Definition
–Records the difference in voltage between the left arm (LA) and right arm (RA) electrodes (Lead I = LA minus RA)
–Is horizontal. Left pole (LA) is positive and right pole (RA) is negative |
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Term
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Definition
–Records the difference in voltage between left leg (LL) and right arm (RA) electrodes (Lead II = LL minus RA)
–Points diagonally downward. Its lower pole (LL) is positive and its upper pole (RA) is negative |
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Term
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Definition
•12 leads (I, II, III, aVR, aVL, aVF, and V1–V6) provide a real-time, 3 dimensional view of the heart's electrical activity.
•Record voltage currents in the heart.
•Leads are placed on the limbs and chest.
•Specific electrode locations assess different segments of the heart. |
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Term
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Definition
•Single stimulus (beat)
•Appear earlier in the cycle
•Atrial, junctional, or ventricular foci become irritable |
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Term
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Definition
•Rapid rhythms originating in very irritable automaticity foci
•Defined by rate, range, and origin |
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Term
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Definition
•Sinoatrial (SA) node
•SA block
•Misses one pacing stimulus
•Sufficient pause |
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Term
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Definition
•Leads are V1–V6.
•Record electrical voltages transmitted onto the horizontal plane of the body (a plane dividing the body into upper and lower halves).
•Record electrical voltages directed anteriorly, posteriorly, and to the right and left |
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Term
| Augmented Limb (Extremity) Leads |
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Definition
•The voltages recorded at each extremity are electronically augmented by 50% by the electrocardiograph.
–aVR (augmented Voltage, Right arm)
–aVL (augmented Voltage, Left arm)
–aVF (augmented Voltage, Left Foot) |
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Term
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Definition
–Records the difference in voltage between left leg (LL) and left arm (LA) electrodes (Lead III = LL minus LA)
–Points downward. Lower pole (LL) is positive and its upper pole (LA) is negative
–Einthoven’s triangle: graphic representation of standard limb leads |
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Term
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Definition
–Records the difference in voltage between the left arm (LA) and right arm (RA) electrodes (Lead I = LA minus RA)
–Is horizontal. Left pole (LA) is positive and right pole (RA) is negative |
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Term
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Definition
–Records the difference in voltage between left leg (LL) and right arm (RA) electrodes (Lead II = LL minus RA)
–Points diagonally downward. Its lower pole (LL) is positive and its upper pole (RA) is negative |
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Term
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Definition
•12 leads (I, II, III, aVR, aVL, aVF, and V1–V6) provide a real-time, 3 dimensional view of the heart's electrical activity.
•Record voltage currents in the heart.
•Leads are placed on the limbs and chest.
•Specific electrode locations assess different segments of the heart. |
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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
| Spontaneous electrical impulse generation. Performed by P cells |
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Term
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Definition
| Waveform having two distinct phases; partly positive and partly negative from the isoelectric line |
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Term
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Definition
| receive and conduct electrical stimulus. Performed by cardiac cells. |
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Term
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Definition
| Movement of ions across the cell membrane that causes the inside of the cell to become positive |
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Term
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Definition
| Impulse originating from a source other than the sinoatrial (SA) node |
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Term
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Definition
| Ability of the cell to respond to an outside stimulus |
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Term
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Definition
| Small bundle of nerve fibers |
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Term
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Definition
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Term
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Definition
| Having a uniform size and shape |
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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
| The premature activation of part of the ventricle due to transmission of impulses along an accessory pathway that is not subject to the normal delay of the atrioventricular (AV) node. Travels to the ventricles via a pathway other than the AV node or bundle of HIS |
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Term
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Definition
| Condition in which an impulse returns to stimulated tissue that was previously depolarized |
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Definition
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