Basics Flashcards
Wolf-Parkinson-White Syndrome
Bundle of Kent. PR interval is less than 0.12. Wide QRS with Delta waves.
Atrial Fibrillation
Artial rate is greater than 350. Ventricular rate varies. Chaotic baseline (fibrillatory waves). Irregularly Irregular.
Hypothermia
All intervals are prolonged. Osborne waves: ST elevation with abrupt ascent at the J point and plunge back to baseline. Slow A-fib.
Interpolated PVCs
PVC that falls between two regular complexes and don’t disrupt the normal cardiac cycle.
Sinus Node Dysfunction
Degenerative disease of the elderly. Periods of bradycardia, tachycardia and prolonged pauses.
Myocardial Ischemia
ST Depression greater than 1mm in 2 or more leads. Inverted or tall peaked T waves ( larger than 6mm in limb leads and 12mm in precordial leads). T wave becomes more symmetrical.
Sinus Arrest
SA node transiently stops and 3 or more beats are lost.
Second Degree Heart Block Type II
“mobitz” 2:1 conduction. PR interval is prolonged but constant. Intermittently a P wave is not followed by a QRS
Ventricular Fibrillation
Chaotic baseline. No heart contraction.
Lown-Ganong-Levine Sydrome
James fibers. PR less than 0.12. Normal QRS. Absence of Delta waves.
Junctional escape rhythm
Rate of 40-60. Inverted P waves (P waves can be inverted, absent or after the QRS) with short PR interval.
Lead II position on axis
+60 degrees
Anterior MI
Changes in V1-V4
Bundle Branch Blocks
Prolonged QRS. Must be greater than 0.12 seconds. RR’ configuration (rabbit ears) in the chest leads.
Anteroseptal MI
V1-V3
Drugs that prolong the QT interval
Quinidine, Procainamide (pronestyl), disopyramide (norpace), amiodarone (cordarone), sotalol (betapace), TCAs, Phenothiazines, Erythromycin.
Hypocalcemia
QT prolongation. Easily progresses to torsades or V-tach.
Third Degree Heart Block
Upright and round P waves “march” through the QRS complexes. No association between the P waves or the QRS complexes.
Multifocal Atrial Tachycardia
Rate of 120-150. Irregular rhythm. Similar to wandering atrial pacemaker but a faster rate.
aVF
Towards the Foot. Inferior view of the heart.
Hemiblocks
Change in the axis without a change in the duration of the QRS.
Small Square Height
1 mm or 0.1 mv
Electrical Alterans
Changing amplitude of the QRS complex
Large Box Duration
0.20 Seconds
Second Degree Heart Block Type I
“wenckebach” PR interval progressively increases until a QRS complex is dropped and then the cycle repeats.
Atrial Dysrhytmia Characteristics
P waves will differ in appearance, abnormal/shortened/prolonged PR interval. QRS complexes will appear normal.
Left Posterior Hemiblock
Right axis deviation (greater than +120 or +180), Normal QRS duration. Have to exclude other causes of RAD. Best to use subsequent EKGs.
Bifasicular Block
RBBB with LAHB or LPHB. RBBB features with axis deviation.
Right Atrial Enlargement Criteria
P wave larger than 2.5mm and/or if biphasic: The initial component is taller than the terminal component. Can also have RVH, Right Axis Deviation and/or V1 R wave is greater than the S wave.
Premature Ventricular Complexes
Early beat . Wide QRS.
Premature Junctional Complex
Early impulse that arises from the AV node. Inverted P waves (P waves can be inverted, absent or after the QRS). Short PR interval. Followed by a noncompensatory pause.
Right Ventricular Hypertrophy Criteria
Right axis deviation (greater than +90 degrees) V1: R wave greater than the S wave V6: S wave greater than the R wave
Multifocal PVC
PVCs look different
Hypercalcemia
Increased PR interval and QRS complex. Bundle branch and AV blocks. Shortened refractory period (short ST and QT).
Unifocal PVC
PVCs look the same
QT Interval Duration
0.36-0.44 seconds (9-11 small squares)
Inferior MI
Leads II, III and aVF.
First Degree Heart Block
Consistent delay of conduction at the AV node. Consistently prolonged PR interval. Regular rhythm.
Anterolateral MI
V1/2-V5/6
Atrial Tachycardia
Rate of 150-250. P waves will appear different. the PR interval will be shorter than normal.
Left Anterior Hemiblock
Left Axis Deviation (-45 to -90), Tall R waves in lead I, Deep S waves in avf, Normal QRS duration.
R-on-T PVC
PVCs occuring on/near the previous T wave. Can precipitate V-Tach or V-Fib.
Q wave duration
less than 0.04 seconds (one small square)
Pulseless Electrical Activity
Organized ECG rhythm but patient is pulseless. Associated with severe underlying heart disease.
T wave height
5mm in limb leads, 10mm in precordial leads
Normal Electrical Axis
Down and to the left. From 0 to +90 degrees.
Prior Infarction
Pathologic Q waves in the absence of ST segment or T wave abnormalities.
Ventricular Dysrhythmias Characteristics
Wide/bizarre QRS complexes. T waves in the opposite direction of the R wave. Absence of a P wave.
Sinus Pause
SA node transiently stops and 1-2 beats are lost.
Idioventricular Rhythm
Rate of 40-100. Wide bizarre QRS with no P waves.
Ventricular Tachycardia
Rate of 100-250. Regular rhythm. No P waves. Wide/bizarre QRS. Can occur with/without a pulse.
Small Square Duration
0.04 seconds
Polymorphic V-Tach
The appearance of each QRS varies.
Sinus Dysrhythmia
Patterned irregularity. Cycle of slowing then speeding. HR increases with inspiration and decreases with expiration.
Wandering Atrial Pacemaker
Normal rate. Slightly irregular rhythm. P waves that change in appearance from beat-to-beat. The PR interval varies.
Lead I position on axis
0 degrees
Premature Atrial Complexes
Irregular rhythm due to early beat. P wave will appear different then the underlying rhythm. QRS complex is normal. Followed by a non compensatory pause.
Evolution of a Q-Wave MI
1.) Hyperacute T wave changes with ST elevation 2.) Marked ST elevation 3.) Pathologic Q waves with less ST elevation, Terminal T wave inversion 4.) Pathologic Q waves with T wave inversion 5.) Pathologic Q waves with upright T waves
Right Deviation Axis
Between +90 and +180 degrees
Accelerated Junctional Rhythm
Rate of 60-100. Inverted P waves (P waves can be inverted, absent or after the QRS) with short PR interval.
Brugada Syndrome
Autosomal Dominant. Variable St elevation abnormalities. Less than 30 yo, more common in Asians. Treat with an ICD.
aVL
Towards Left Arm. Lateral view of the heart.
PR Interval Duration
0.12-0.20 seconds (3 to 5 small squares)
Right Atrial Enlargement Leads
Lead II and V1 are most helpful
P wave duration
0.06-0.10 seconds (1.5 to 2.5 small squares)
Left Circumflex Artery
Left atrium, anterolateral, posterolateral and posterior left ventricle.
Lead II
From Right arm to the Left leg. Inferior view of the heart.
aVR
Towards Right Arm. Views base of the heart.
Posterior MI
Reciprocal (ST depression) changes in V1-V3. R waves longer than 0.04 seconds and larger than the S wave. Patient is greater than 30 yo.
Pulmonary Embolism
Sinus Bradycardia is most commmon. RBBB in V1-V3. Signs of RAE or RAD. S1 Q3 T3 pattern (Large S wave in lead 1, Deep Q wave and inverted T wave in lead 3).
Couplet PVC
Two PVCs in a row
Supraventricular Tachycardia
P waves can’t be identified so can’t determine is atrial or junctional.
aVR position on axis
-150 degrees
Pathological Q Waves
Longer than 0.04 seconds. 1/3 the height of the R wave (or deeper than 1mm). Present in at least two leads.
Digoxin Toxicity
AV blocks, Tachy-Dysrhythmias. Paroxysmal Atrial Tachycardia with second degree AV block is most common.
Pericarditis with Effusion
Low Voltage EKG. With diffuse ST elevation. Electircal Alterans.
Incomplete Bundle Branch Block
RR’ Configuration with a normal QRS interval
Torsades De Pointes
Polymorphic V-tach. “twisting about the points”
Atrial Flutter
Atrial rate of 250-350. Absent P waves with saw-tooth flutter waves. The number of impulses conducted through the AV node determines the ventricular rate.
Pericarditis
Diffuse ST elevation
Large Box Height
5 mm or 0.5 mv
Monomorphic V-Tach
Each QRS looks similar.
Junctional Tachycardia
Rate of 100-180. Inverted P waves (P waves can be inverted, absent or after the QRS) with short PR interval.
Left Deviation Axis
Between 0 and -90 degrees
QRS complex Amplitude
5-30 mm
QRS Complex Duration
0.06-0.11 seconds (1.5 to 2.75 small squares)
Lateral MI
Lead I, aVL, V5-V6
Hyperkalemia
Tall, peaked T waves. Flattened P waves. First degree AV block. Widened QRS. Merging of S and T waves producing a “sine-wave” pattern.
P wave Amplitude
0.5-2.5 mm
aVL position on axis
-30 degrees
Right Bundle Branch Block
Prolonged QRS (Greater than 0.12), M-shaped RR’ in V1, Wide S-wave in Lead I and V6. T wave is in opposite direction as the terminal portion of the QRS (if they were same direction it would be indicative of ST-T changes).
Lead I
From the Right arm to the Left arm. Lateral view of the heart.
Junctional Dysrhytmias Characteristics
P waves can be inverted, absent or after the QRS. the QRS is normal.
Left Anterior Descending Artery
Anterior/lateral left ventricle, anterior 2/3 of the septum, right and left bundle branches.
Nonspecific Intraventricular Conduction Deficits
Prolonged QRS without features of RBBB or LBBB
Myocardial Infarction
ST elevation greater than 1mm in 2 or more leads. Release of cardiac enzymes.
Conditions with Right Atrial Enlargement
Pulmonic or tricuspid stenosis and tricuspid regurgitation.
Hypokalemia
U waves (extra wave after the T, may be more prominent than the T wave). Flattening of the T wave. ST depression.
Accelerated Idioventricular Rhythm
Rate of 40-100. Wide bizarre QRS with no P waves.
Right Coronary Artery
Right atrium, Right ventricle and inferior/posterior walls of the left ventricle.
Left Bundle Branch Block
Prolonged QRS with a wide R wave (flat or notched top) in leads I and V6.
Lead III position on axis
+120 degrees
aVF position on axis
+90 degrees
Asystole
Absence of any cardiac activity. Flat line.
Septal MI
V1-V2
“Digoxin Effect”
Expected with therapeutic levels. Shortened QT. Flattened T waves. Asymmetric ST depression and T wave inversion in leads with tall R waves. Gradual down slope of the ST.
Left Ventricular Hypertrophy Criteria
Sum of the deepest S in V1/V2 and the tallest R wave in V5/V6 is greater than 35mm R wave in aVL is greater than 11mm Sum of the R wave in Lead I and the S wave in Lead III is greater than 25mm
Lead III
From Left arm to the Left leg. Inferior view of the heart.
Left Atrial Enlargement Criteria
P wave duration longer than 0.10 seconds in the frontal plane (Lead II) often with notching. V1: Terminal potion of the P wave is negative, duration greater than 0.04 seconds and depth greater than 1mm.
