If the P wave > 0.12 sec( 3 mm) usually in any lead. Notched P wave usually in lead I,aVl may be lead II Negative terminal portion of P wave in V1, 1 mm depth and 3 mm width( most specific) Since Mitral valve stenosis is the most common cause of LA enlargement. It is called P Mitrale
P wave > 0.12 sec, 2.5 mm (pecked) usually in Lead II III avf and V1. It is called P pulmonale, because chronic pulmonary disease is frequently the cause.
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P -WAVE P pulmonale Tall peaked P wave. Generally due to enlarged right atrium- commonly associated with congenital heart disease, tricuspid valve disease, pulmonary hypertension and diffuse lung disease. Biphasic P wave Its terminal negative deflection more than 40 ms wide and more than 1 mm deep is an ECG sign of left atrial enlargement. P mitrale Wide P wave, often bifid, may be due to mitral stenosis or left atrial enlargement.
LEFT VENTRICULAR HYPERTROPHY AND RIGHT VENTRICULAR HYPERTROPHY So, we have to start looking at the S waves and R waves
Voltage criteria : 1. R Lead 1 or avl > 20 mm 2. R V5 or V6 + S V1 > 35 mm 3. In sever LVH There will be ST segment depression and T wave inversion in Lateral leads (I avl,v5 V6)
Prominent R in V1 ( =or > S wave). prominent S in V 6( = or > R wave ). Usually associated with RT axis deviation(>+110). In sever RVH ST depression & T wave inversion V1 may be V2 V3
The impulse will be conducted from : SA node --- AV node ---- Bundle of His --- RT & LT bundle branches. Any interference with this path way leads to impulse delay or block Level of the block : SA block, AV block, Bundle branch block (BBB), Fascicular block
The most common site of block. Of three degrees : 1. 1 st Deg. : all impulses from SA node will reach the ventricle but with delay, normal P wave followed by normal QRS but the PR interval is > 0.2 sec (5mm)
Characterized by PR Interval > 0.20 seconds Delay in conduction AV Node Prolonged PR Interval constant Usually asymptomatic Least concerning of the blocks
Two types : 1. Mobitz type 1 (wenchebach phenomena): Progressive PR segment prolongation till the beat will drop out, P wave which will not followed by QRS, the cycle will recurs again.
P wave which is not followed by QRS with out preceding PR segment prolongation. We see P waves> than QRS complexes, if the P waves are double the no. of QRS, called 2:1 block, if every 3 Ps one QRS complexes, called 3:1 block and so on. The more the no of P for QRS the more sever the block.
The impulse generated in the SA node will not pass at all to the ventricle, the lower pace maker in the Perkinje fibers will act to stimulate the ventricle. There are P waves not related to QRS complexes, PP interval regular and different from RR interval also regular at other rate (30-40 b/min)
RT BBB : QRS > 0.12, Broad S lead I and V6 rsr in V1. T inversion in V1-V3
QRS duration 110ms rsr pattern or notched R wave in V 1 Wide S wave in I and V 6
RBBB
QRS > 0.11 RSR in lead I avl, V5 V6. ST segment depression, T wave inversion in the same leads. High voltage but LVH cannot be diagnosed.
Look at the ECG, regular or irregular. If it is regular irregularity or irregular irregularity. Look for the P wave and its relation to QRS Look to the Shape of the P wave and QRS configuration.
'supraventricular' (sinus, atrial or junctional) produce narrow QRS complexes ventricular produce narrow QRS complexes
There P wave for each QRS. PP or RR < 60 beat/mint. Frequently seen in : Athletes, Hypothyroidism Hypothermia, Increased intracranial pressure, inferior MI.
Hear rate > 100 b/min. P wave for each QRS. Seen in : fever, anxiety, exercise, anemia, hyperthyrodsim.
Premature Atrial Contraction PAC Basically the ECG is regular, some impulses are not, but there is P wave (which looks different from previous one) for each QRS (which is normal). The PR interval is changeable in these beats ( shorter or longer).
Very common dysrrhythmia. Heart rate 160-220 b/m. Usually regular rhythm.
Rapid atrial rate 250-350 b/m. Usually there is AV block (2:1, 3:1,4:1 etc.) Usually the PP rate is Faster than RR rate, the atrial rate is regular, ventricular rate could be regular or irregular depending on the degree of block. Because of very frequent P wave the base line in undulated, called saw teeth appearance.
Completely irregular (irregular irregularity). No P wave but there is f wave (fibrillatory wave). Atrial rate 350-450, ventricular rate is totally irregular.
Generally the ECG is regular with some beats looks wide,no preceding P wave, wide QRS and T wave in opposite direction to QRS. Usually followed by compensatory Pause. Could be single or multiple.
Runs of wide QRS complexes fast tachycardia, no preceding P wave, regular. Usually serious dysrrhytmia, may progress to more serious Ventricular fibrillation.
Fatal dysrhythmia, no actual QRS complexes, rather bizarre and chaotic undulation of the base line. Unconscious patient No central pulsation No respiration
Hypokalemia : ECG can be used as guide to give clue about serum potassium level. Hypokalemia leads to flattening of T wave, may be U wave. Hyprekalemia showed pecked T wave
Flat T wave
Pecked T wave