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cvs.electrocardiogram

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What are the three stages of a MI?
E: 1. Abnormal T wave, which is tall, prolonged, inverted, or upright. Hyperacute tall T waves are typically seen in the first hour or two of MI evolution. The T wave usually becomes inverted after ST-segment elevation has occurred and may remain inverted for days, weeks, or years.
2. ST-segment elevations in leads facing the infarcted myocardial wall and reciprocal ST depressions in opposite leads. ST-segment changes are the most common ECG signs of acute MI. ST-segment elevations rarely persist > 2 weeks except in patients with a ventricular aneurysm.
3. Appearance of new Q waves, often several hours or days after the onset of MI symptoms. Alternatively, the amplitude of the QRS complex is decreased. Q waves may develop earlier when thrombolytic therapy is administered (Fig. 3-2).

A: T, ST, Q
What are the EKG manifestations of atrial infarction?
E: 1. Depressed or elevated PR segment
2. Atrial arrhythmias
* Atrial flutter
* Atrialfibrillation
* AV nodal rhythms

A: ect
The venous a wave appears (before,during,after) the P wave.
E: During the course of one cardiac cycle, the electrical events (ECG) initiate and therefore precede the mechanical (pressure) events, and the latter precede the auscultatory events (heart sounds) that they produce. Shortly after the P wave, the atria contract to produce the a-wave; S4 may succeed the latter.
A: aft
When does S3 occurr in relation to the QRS complex? (before,during,after)
E: The QRS complex initiates ventricular systole, followed shortly by LV contraction and the rapid buildup of LV pressure. Almost immediately, LV pressure exceeds left atrial (LA) pressure to close the mitral valve and produces S1. When LV pressure exceeds aortic pressure, the aortic valve opens, and when aortic pressure is once again greater than LV pressure, the aortic valve closes to produce S2 and terminate ventricular ejection. The decreasing LV pressure drops below LA pressure to open the mitral valve, and a period of rapid ventricular filling commences. During this time, an S3 may be heard (Fig. 3-3). (For simplification, right-sided heart pressures have been omitted.)
A: aft
What is the atrial rate in atrial fibrillation?
E: AF differs from all other SVTs by having totally disorganized atrial depolarizations without effective atrial contraction. An ECG may occasionally show small, irregular waves of variable amplitude and morphology, occurring at a rate of 350-600/min, but these are often difficult to recognize on a routine 12-lead ECG.
A: 350
What is the commonest atrial rate in atrial flutter and what is the commonest ventricular rate?
E: The flutter rate (i.e., the atrial rate) in atrial flutter ranges between 250 and 350 bpm. The most common flutter rate is 300 bpm, and the most common ventricular rates are 150 and 75 bpm, respectively.
A:300,150
What is the upper limit of sinus rhythm?
E:Atrial tachycardias have slower atrial rates, ranging from 150 to 250 bpm.
A:250
What is the commonest cause of atrial tachycardia with block?
E: Unlike AF, atrial tachycardia (or paroxysmal atrial tachycardia) and atrial flutter demonstrate a regular ventricular rhythm and are characterized by regular and slower atrial rhythms (Table 3-1). The flutter rate (i.e., the atrial rate) in atrial flutter ranges between 250 and 350 bpm. The most common flutter rate is 300 bpm, and the most common ventricular rates are 150 and 75 bpm, respectively. Atrial tachycardias have slower atrial rates, ranging from 150 to 250 bpm. The most common cause of atrial tachycardia with block is digitalis toxicity.
A: dig
What are the four axes of comparison when we try to distinguish between atrial fibrillation, atrial flutter and atrial tachycardia?
E: We look at atrial rhythm, atrial rate, AV block (conducted vs non-conducted beats) and the ventricular rate. Flutter and tachycardia are regular rhythms; atrial tachycardia is cannot be faster than 240-250; flutter is always above 240 and is usually around 300.
A: rhythm, atrial rate,block, vent
Intermittent cannon waves in the jugular venous pulse suggests which condition?
E: The clinical hallmark of AV dissociation is the presence of intermittent cannon waves in the jugular neck veins.
A: AV disso
What are the three EKG findings in VT?
E: Three ECG findings are virtually pathognomonic of VT: AV dissociation, capture beats, and fusion beats (Table 3-2).
A: AV, fus, captu
What is a fusion beat?
E:A fusion beat has a QRS morphology intermediate between a normally conducted narrow beat and a wide-complex ventricular beat.
A: intermed
What is a capture beat?
E: A capture beat is a normally conducted sinus beat interrupting a wide-complex tachycardia.
A: norma
What are the contradindications to stress testing?
E: 1. MI acute or pending
2. Unstable angina
3. Acute myocarditis or pericarditis
4. Left main CAD
5. Severe aortic stenosis
6. Uncontrolled hypertension
7. Uncontrolled cardiac arrhythmias
8. Second- or third-degree AV block
9. Acute noncardiac illness

A: MI, unstable, cardit, non-card
What sort of coronary artery disease is a contraindication to stress testing?
E: Left main CAD
A: L
Which type of AV block is this: Prolongation of the PR interval due to a conduction delay at the AV node.
E: First degree AV block
A: firs
Which type of second degree AV block is this: The PR interval lengthens with each successive beat until a beat is dropped and the cycle repeats itself. (I/II)
E: Type I: Wenkebach
A: I
Wenkebach phenomenon is seen in Type (I/II)?
E: Type I
A: I
Which type of AV block is this: The PR intervals are prolonged but do not gradually lengthen until a beat is suddenly dropped. The dropped beat may occur regularly, with a fixed number (X) of beats for each dropped beat (called an X:1 block) (I/II).
E: Type II
A: II
Which is the more common type of second degree AV block: Wenkebach phenomenon or Type II?
E: Wenkebach (Type I) is more common.
A: Wenke
What is second degree AV block, Type II associated with?
E: Bundle branch blocks
A: bundle
What is the ventricular rate in 3rd degree AV block?
E: Third-degree AV block (complete heart block): The atria and ventricles are controlled by separate pacemakers. It is associated with widening of the QRS complex and a ventricular rate of 35-50 bpm.
A: 35
What are the EKG changes seen in hyperkalemia?
E: A tall, peaked, symmetrical T wave with a narrow base (so-called tented T wave) is the earliest ECG abnormality and is usually present in leads II, III, V2, V3, and V4. Shortening of the QT interval, widening of the QRS interval, ST-segment depression, flattening of the P wave, and PR-interval prolongation follows this. Eventually, the P waves disappear and the QRS complexes assume a configuration similar to a sine wave, eventually degenerating into ventricular fibrillation (VF). Widening of the QRS complex can assume a configuration consistent with atypical right bundle branch block (RBBB) or left bundle branch block (LBBB) making the recognition of hyperkalemia more difficult. Unlike typical RBBB, hyperkalemia often causes prolongation of the entire QRS complex.
A: tall, PR, flat, sine
The QT segment (shortens/prolongs) in hyperkalemia?
E: It shortens.
A: short
At what K level is ventricular fibrillation seen in experimental hyperkalemia?
E: Tall, symmetric T: 5.7
Reduced P amp: 7.0 mEq/L
Prolonged PR:7.0
Absent P:8.4 mEq/L
Widened QRS: 9-11 mEq/L
Vfib:12
A: fib.*12
The QTc interval (shortens/lengthens) in hypercalcemia.
E: Hypercalcemia shortens the QT interval, particularly the interval between the beginning of the QRS complex and the peak of the T wave. The abrupt slope to the peak of the T wave is most characteristic of hypercalcemia. Another cause of shortened QT interval is digitalis toxicity.
A: short
What is the normal PR interval interval (in milliseconds)?
E: The normal range for the PR interval is 120-200 milliseconds. It is not significantly related to age, sex, or heart rate.
Q:120-200
What is the normal QT interval (in milliseconds)?
E: The normal range for the QTc is 0.36-0.44 sec. A prolonged QTc is defined as QTc > 0.44 sec.
A: 360-440
Does the PR interval change with heart rate?(Yes/No)
E: It is not significantly related to age, sex, or heart rate.
A: N
What happens to the QT interval when the heart rate goes up? (shortens/same/prolongs)?
E: It shortens. The normal range for the QT interval also is unrelated to age, but it does vary with heart rate. As the heart rate increases, the QT interval shortens. To help evaluate a QT interval independent of heart rate, the corrected QT interval (QTc) can be calculated:
QTc (in msec) = measured QT (in msec)/square root of the R-R interval (in sec)
A: shor
Is a QRS axis of 120+ compatible with left anterior hemiblock? (Yes/No)
E: This diagnosis requires the presence of a QRS of -60° to -90° in the frontal plane. A frontal plane QRS axis of +120° is consistent with right axis deviation and is therefore not compatible with a diagnosis of left anterior hemiblock (left anterior fascicular block).
A:N
List the diagnostic criteria for left anterior hemiblock?
E: * QRS axis -60° to -90°
* Small q-wave in lead I
* Small r-wave in lead III

A: -60.*-90, small q.*I, small r.*III
What are the 5 features of right ventricular hypertrophy?
E: * R greater S in V1 or V2
* R 5+ mm in V1 or V2
* Right axis deviation
* Persistent rS pattern V1-6
* Normal QRS duration
A: r.*s, r.*5, right axis, rS, normal qrs.*
What are the congenital causes of prolonged QT interval?
E: * With deafness: Jervell syndrome
* Without deafness: Romano-Ward syndrome
A: Jerve, romano
What electrolyte abnormalities can cause prolonged QT interval?
E: Hypocalcemia, hypokalemia, hypomagnesemia
A: hypoc, hypok, hypom
Which drugs commonly cause prolonged QT?
E:Drugs: class IA/IC antiarrhythmics, tricyclic antidepressants, and phenothiazines
A: I/IIc, phenothi, TCA
What sort of diets can cause prolonged QT?
E: Liquid diets
A: liquid
What can cause prolonged QT other than liquid diets, electrolyte abnormalities and drugs?
E: * Hypothermia
* Central nervous system injury (least common cause)
* CAD
* Cardiomyopathy
* Mitral valve prolapse
A: CAD, cardiomyopathy, MVP, hypothermia, CNS
QT prolongation, in certain patients, is associated with a risk of VF and death. True/False?
E: True
A: T
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