3. P Wave Overview - ECG assessment and ECG interpretation made easy

[Music] hello my dear students now as a part of the continuation of this ecg lecture series in this session i will be discussing the abnormalities of the p wave so if you take the p wave p wave it is the first positive deflection on the ecg right so let me just show you that so this is the first positive deflection within the ecg right now why is this p wave due to this particular p wave it is due to atrial depolarization right it is due to atrial depolarization now if you take the p wave what is the morphology of the p wave it is having a smooth surface which is monophasic now what do you understand by the word monophasic in the sense the p wave in all the leads it is having a positive deflection right p wave in all the leads it is having the positive reflection now there are certain exceptions there are certain leads where you have biphasic p wave and there are certain leads where you have a negative p wave as well what are those leads we will discuss now the next important point here what you need to know is what does this particular p wave represent right that is your atrial depolarization but if you take this as the p wave it has two halves first half and as well as the second half the first half of the p wave it is due to right atrial depolarization and second half of the p wave it is due to left atrial depolarization right so first half is your right atrial depolarization and second half is your left atrial depolarization so this is your p wave and i said you the p wave is monophasic but you see a question so the question is in which of the following leads the p wave is biphasic lead to lead 3 avr and lead v1 so biphasic p wave right how it will be this is your biphasic p wave right this is your biphasic p wave so this biphasic p wave is seen in lead v1 in lead v1 you have the biphasic p wave now in this biphasic p wave the first half it represents right atrial depolarization the second half it represents the left atl depolarization write the second half it represents the left atl depolarization and let me show you the ecg strip so this is the ecg strip with biphasic p wave now out of which i have said you the first half with positive deflection that is your right atrial depolarization the second half with negative deflection that is your left atrial depolarization now after having discussed about the morphology of the p wave next before that i have said you that p wave will be having a negative deflection in lead avr right so in lead avr the p wave it is having a negative deflection okay and why is that let me explain so right you see this image where do you place the avr the avr is placed at this point and how will be the wave of depolarization which moves the wave of depolarization it moves from the ac node and then av node from here the wave of depolarization will be towards the apex that means the wave of depolarization is moving away from the abr and that is the reason why in avr the p wave will be negative right that is the reason why in avr the p wave will be negative now after having discussed about the morphology of the p wave in all the leads now the next question is about the axis right let me discuss that so you see this question normal p wave axis is approximately 90 degrees approximately 60 degrees approximately 120 degrees approximately 30 degrees now the normal p wave will have an axis of approximately 60 degrees now let me explain you why it is 60 degrees so if you see this particular image in this image you can make out that the wave of depolarization from the ac node it is moving towards the apex when it is moving towards the apex in your hexageal diagram right so you go back to my section on the axis there i have explained you a very detailedly about the hexageal diagram so in the hexagon diagram the wave of depolarization or the direction of the depolarization in a normal heart is towards more or less 60 degrees so if you take the p wave also the p wave axis it is nearly around 60 degrees so in a simple term if the question is asked what is a normal p wave axis the answer is 60 degrees now after having explained about the axis now let me also tell you one important point about the atrial repolarization so if you take this atrial repolarization remember we don't have any separate wave for the atrial repolarization and the question is why because the potential which is generated by atrial repolarization is very minimal right the potential which is generated by the atrial repolarization is very minimal right it is very small and the potential which is generated by the atrial repolarization is masked by the qrs complex right it is superimposed by the high amplitude the qrs complex so that is the reason why for the atrial repolarization there is no separate wave right there is no separate wave for the atrial repolarization now you see the question here so the question is the amplitude of atrial repolarization is less than 50 microvolts less than 100 microvolts less than 1 millivolt less than 1 volt so the answer to this question is less than 100 microvolts so remember this very important point the repolarization the potential which is generated is less than 100 microvolts which is a very low amplitude and this particular low amplitude is superimposed by the high amplitude the qrs complex right it is superimposed by high amplitude qrs complex all right now after having discussed about the atl depolarization atrial repolarization and as well as the axis now let me tell you about the amplitude and as well as the duration of the normal p wave so right so if you see this question the amplitude and duration of the normal p wave in the limb leads so amplitude is different in the limb leads and as well as the chest leads so the limb leads they include lead 1 li-2 and as well as lead 3 so the amplitude and duration of the normal p wave in the limb leads it is the options given to you is less than 1.5 mm and 120 milliseconds less than 2.5 mm and less than 120 milliseconds less than 2 mm less than 1 to 10 milliseconds less than 3 mm and less than 110 milliseconds so the answer to this question here is less than 2.5 mm and less than 120 milliseconds so this is the amplitude and duration of the normal p wave in the limb leads so remember this very important point the amplitude in case of the chest leads if you see it is less than 1.5 mm right less than 1.5 mm whereas the amplitude in the limb leads it is less than 2.5 mm right less than 2.5 mm now what do you understand by this word 1.5 mm and 2.5 mm let me tell you i have discussed in detail about like how much is equal to 1 mm on the ecg how much it is equal to 2 mm on the ecg i have discussed in detail in my section of the ecg basics right now and the duration of the p wave either you take in the limb leads or you take in the chest leads it is like standard it is less than 120 milliseconds so less than 120 milliseconds duration it is nothing but it is equivalent to less than three small boxes on the x axis right less than three small boxes on the x axis okay because one small box is around 40 milliseconds right one small box is around 40 milliseconds so 40 multiplied by 3 that becomes around 120 milliseconds all right so this is about the normal p wave the amplitude less than 2.5 mm and duration 120 milliseconds so duration is on the x axis amplitude is on the y axis and this is in the limb leads right this is in the limb leads okay now i'll just show you one normal ecg as well so this is the normal ecg and if you see this the amplitude in lead 2 right so lead 2 is called as the standard lead why because the wave of depolarization is towards your lead 2 in your hexagon diagram so that is the reason why your lead to right that is the reason why lead to it is considered as the standard lead so in limb leads the amplitude is less than 2.5 mm whereas in the chest leads the amplitude is less than 1.5 mm so 1mm is nothing but one small box on the y-axis less than 2.5 mm is less than two and half small boxes okay so this is about the normal p wave and i have said you that in v1 it is biphasic right you see here it is biphasic right and you take in avr i have said you it is a negative complex the p wave will be negative right and remaining all it is a monophasic positive deflection right remaining all is monophasic positive deflection so whatever i have discussed now is completely about the normal p wave now let me discuss about the abnormalities of the p wave so if you take the abnormalities so the first question is this patient is suffering from mitral stenosis tricuspid stenosis iotic stenosis mitral regurgitation now i'll just zoom the ecg as well for you right so this is slightly little enlarge now when we are discussing about the p wave right i will be discussing mainly about the abnormalities of the p wave in the ecg now you see this p wave here this is your p wave right this is your p wave now what should be the normal p wave amplitude less than 2.5 mm and if you calculate the p wave amplitude here it is occupying three small boxes that means the amplitude is more than 2.5 mm right the amplitude is more than 2.5 mm so this particular patient is having increased amplitude of the p wave and where do you have that so the options given to you are mitral stenosis tricuspid stenosis iotic stenosis mitral regurgitation so you will have this in a clinical scenario of tricuspid stenosis right you will have this in clinical scenario of tricuspid stenosis so amplitude more than 2.5 mm in lead 2 this we call as p pulmonal right this we call it as the p pulmonal all right now what does this p pulmonal represent right let me discuss in detail about the p pulmonary so p pulmonary it tells that the amplitude of the p wave is more than 2.5 mm in the limb leads and it represents right atrial enlargement right it represents the right atl enlargement okay that is a very very important point that means the p wave it is taller right the p wave it is taller right i'll just show you that so this is the p wave which is tall that is more than 2.5 mm that is called p pulmonal right that is called p pulmonary now followed by that you see the similar right atrial enlargement how it will be in the chest leads that is in lead v1 so this is your right atrial enlargement in lead 2 whereas if you take the right atrial enlargement in lead v1 right in lead v1 what is that you will have what did we discuss about the normal v1 the first half of the p wave represents the right atrial enlargement so in your right atrial enlargement what will happen is the first half of the p wave that is initial positive deflection of the p wave in v right so this is your right atl enlargement right this is your right atrial enlargement all right now the next important point that you need to know is that in right atrial enlargement the initial half will be more than 1.5 mm right normally how much it is normally it is only just 1 mm in normal right atrium but whenever there is right atrial enlargement the initial half of the p wave in lead v1 it will be more than 1.5 mm amplitude right now after having discussed about the right atl enlargement there are certain criteria for the right atrial abnormality what is the criteria so whatever i have discussed in lead to whatever i have discussed in lead v1 right everything i just summarize in one slide so in right atrial abnormality you will have a peaked p wave amplitude of more than 0.25 millivolts that is called p palm nail so more than 0.25 millivolts so that is what that is equivalent to more than 2.5 mm right and prominent initial positivity in lead v1 or v2 how much is that more than 0.15 millivolts so that is equivalent to more than 1.5 mm right and increased area under initial positive portion of the p wave in lead v1 how much is that more than point zero six millimeter second and they will have the right axis deviation of the p wave you take the normal axis of the p wave the normal axis of the p wave it is 60 degrees right normal axis of the p wave is 60 degrees but here there will be rightward shift of the mean p wave axis right and how much is that that is more than plus 75 degrees that is more than plus 75 degrees okay right so this is about the features of the right atrial abnormality so let me just show you a small strip of this right atrial abnormality and then we will do some mcqs on that right so if you see this ecg strip over here this particular ecg strip right you can make out the p wave here right so you can right so you can make out the p wave here where the amplitude is more than 2.5 mm which is nothing but your p pulmonal right which is nothing but your p pulp nail now you see the question also following are the causes of p palm nail except pulmonary artery hypertension tetralogy of fallow and pulmonic stenosis in right to left sided shunts tricuspid stenosis iotic regurgitation the answer to this question is the iot regard station now remember in which of the following clinical scenarios you will have the people nail is you will have people nail wherever there is right atrial enlargement right wherever there is right atrial enlargement you will have this p pulp nail you take pulmonary artery hypertension there is increased after load on the right ventricle there will be right ventricular hypertrophy and subsequently there will be increase in your right ventricular end diastolic pressure and that will exert the pressure on the right atrium and there will be right atrial hypertrophy causing p-pulp nail and similarly you take in case of tetralogy of fallow and pulmonic stenosis in case of tetralogy of fallow and pulmonic stenosis there will be right ventricular hypertrophy increase in your right ventricular endoscopic pressure and there will be also increase in your right atrial pressure subsequently and you take in case of tricuspid stenosis so in tricuspid stenosis also there is increase in your right atrial pressure and thereby there will be right atrial enlargement there will be p pulmonary right and in case of the other important clinical scenario what you need to remember is core pulmonal right that is in case of core pulmonal so even in case of carpal nail you will have this particular the people nail why again same reason there in carpal meal there will be right ventricular dilatation and right ventricular hypertrophy there will be increase in your right ventricular and diastolic pressure and subsequently there will be increase in your right atrial pressure and thereby the individual will have the p pulmonary okay so the conditions where you will have p-polymer that is in pulmonary artery hypertension tetralogy of fallow tricuspid stenosis and as well as the carpal name now you see the next question so the question is this patient should undergo treatment with adrenaline the patient should undergo surgery that is pbmv that is perputain is balloon mitral valvetomy treatment with digoxin surgery that is coronary artery bypass graft right so i'll just slightly zoom the ecg right so this is the ecg and the abnormalities has been circled over there right so this is the abnormality now what is the shape of this particular abnormality it is m shaped right the shape of this abnormality is m shape and what is this called this is called as p mitral right this is called as p mitral now where do you have this p mitral this p mitral you will have this in patients with the mitral stenosis right this p mitral you will have this in patients with the mitral stenosis okay so in patients with mitral stenosis what is the treatment the treatment what you have to give is pbm that is percutaneous balloon mitral valve watering i will be discussing in detail about the p mitral but before that you see this is the pbmv right this is your pbmv right that is percutaneous balloon mitral valve watering so what do we do here we bring an inner balloon up to the level of the miter valve and we keep at the level of the miter valve and we inflate the balloon so that will cause the opening of the miter valve and that is called as pbmv that is percutaneous balloon michael valvotomy now you will have this particular p mitral in case of left atrial enlargement right so right so in case of left atrial enlargement you will have the presence of the p mitral okay now this left atrial depolar what actually is happening here right why do you have that now in left atrium enlargement which half of the p wave should get affected the second half of the p wave should get affected so the first half of the p wave it is normal but second half of the p wave right you have the depolarization which will be lasting longer than the normal time right so if you take the duration of the p wave in left atrial enlargement the duration will be more than 120 milliseconds right the duration will be more than 120 milliseconds okay that is in case of the left atrial enlargement and one important point you should know is that in left atrial enlargement or in case of p mitral the amplitude does not change okay so the height of the p wave it remains within the normal limits right the height of the p wave it remains within the normal limits whereas in p pulmonal the height is increased but the duration is normal but whereas in p my trail the duration is increased but amplitude is normal right amplitude is normal okay now the next important point you should know is about this particular shape of the p wave which is like m shape that is called as the p mitral now what is the criteria for left atrial abnormality so the criteria for the left atrial abnormality is number one there should be prolonged p wave duration right there will be prolonged p wave duration right so that is around more than 120 milliseconds right that is number one next the prominent notching of the p wave you see here so this is a notch right this is a notch and what should be the distance between the two prominences that is there should be prominent notching of the p wave and that should be most obvious in lead to with interval between notches right the interval between the notches it should be more than 40 milliseconds right so this distance should be more than 40 milliseconds so that is when you call it as the p my trail right that is when you call it as p mitral then apart from that if you take the ratio of p by pr segment right ratio of p in lead 2 and as well as the pr segment the duration of the pr segment the ratio between p and pr segment it should be more than 1.6 to call it as p my trail what is this i will discuss right we have what is called morris index and as well as macros index i will discuss both morris and as well as the macros index and the other point is they should have what is called the p terminal force now what is this particular the p terminal force that is if you take the second half of the p wave in lead v1 how much it should be deep the depth should be more than 2 mm normally how much it is it is only just 1 mm deep but in lefty ideal enlargement the depth should be more than 2 mm and the duration right the duration it should be more than 40 milliseconds then we call it as the p terminal force and apart from that there should be left axis deviation of the p wave and how much should be that left axis deviation that is around minus 30 and minus 45 degrees right minus 30 and minus 45 degrees so this is the criteria of the left atrial abnormality right and let me show you that so this is you in your lead v1 okay so this is your p terminal force the duration should be more than 40 milliseconds and the depth should be up to 2 mm right the depth should be up to 2 mm normally it is only up to 1 mm but here in p terminal force you will have the depth of the second half of the p wave in lead v1 it will be up to 2 mm so this is what is a criteria of left atrial enlargement or left atrial abnormality and the p mitral now let me discuss about the two important index that is morris index and as well as the macros index that is so first you see about the morris index right your morris index it is nothing but your p terminal force in lead v1 and that is your p terminal force in lead v1 that means what what is the criteria that is in case of lead v1 the second half of the p wave the depth should be up to 2 mm or more than or equal to 2 mm and the duration of the second half of the p wave it should be more than right it should be more than 40 milliseconds that is what is your morris index that is what is nothing but your morris index okay now after having discussed about the morris index now let me take up the question on the macros index you see this question so the question is what is the macros index for mitel synosis the options are 1 1.6 more than 1.6 and less than 1 so the answer to this question is more than 1.6 now how do you calculate this particular macros index right how do you calculate this macros index that is so this is your p wave right and this is your pr segment right this is your pr segment so macros index how do we calculate p by pr segment right p by pr segment is nothing but your macros index now you need to know that what is the normal macros index the normal macros index it is 1 to 1.6 whereas if the macros index if it is like more than 1.6 that indicates p mitral right that indicates p mitral and if the macros index is less than 1 then that indicates the p pulmonal right that indicates the p palm nail so that is what is your macros index so morris index and as well as macros index it is mainly helpful to decide whether there is right atrial or left atrial abnormality is present or absent now summarizing all the abnormalities right atrial abnormality and as well as the left atrial abnormality so if you see this right this is the summary right so this is your normal p wave which is monophosia can lead to and biphasic in lead v1 and in right atrial enlargement you have the presence of the p pulmonal and the first half of the p wave in lead v1 it is enlarged and if you take in case of left atl enlargement right you have the p mitral which is the p wave of m shape in lead two and second half of the p wave right the second half of the p wave it is more deeper and more wider right it is more deeper and as well as more wider that is what you will have in case of left atrial enlargement whereas in biatrial enlargement you will have both p mitral will be there and as well as the p pulmonal also will be there so this is the summary of both right atrial and as well as left atrial abnormalities and where do you have left leftyl abnormalities that is in case of mainly mitral stenosis you will have the left atrium enlargement and how will be the ecg changes we have discussed that in detail now after having discussed about the right atrial line as well as left heel abnormalities and subsequent p wave abnormalities on the ecg now let me discuss how do you assess the rhythm based on the p wave morphology and based on where the p wave is appearing so if you see the next question these questions are like how to interpret the rhythm based on the p wave morphology so you see the question what is the rhythm normal sinus rhythm irregularity ventricular rhythm accelerated junctional rhythm right so you see this is the ecg and let me just tell you the answer first and then i will explain you so the answer is accelerated junctional rhythm now how to make out this right how to make out it is an accelerated junctional rhythm so if you see the p wave the p wave it is inverted p wave whatever you are having here right now if the inverted p wave if it is having short pr interval if it is having normal pr interval that will decide the rhythm so in a scenario of inverted p wave in the ecg what you need to check you need to check the pr interval for suppose if the pr interval if it is less than 120 milliseconds right if the pr interval is less than 120 milliseconds then we call it as the origin of the impulse is near the av junction okay the origin of the impulse is near the av junction okay so which we call it as accelerated junctional rhythm so this we call it as accelerated junctional rhythm now first of all you should understand why there will be inverted p wave first so when there is inverted p wave right when there is inverted p wave it tells you that there is non sinus origin of the p wave right it indicates a non-sinus origin of the p wave and upon that if the pr interval is less than 120 milliseconds then it is called accelerated junctional rhythm so you have the inverted p wave and the pr interval it is short right the pr interval it is short that is less than 120 milliseconds and that we call it as accelerated junctional rhythm now followed by that if you take the pr interval right if the pr interval is more than 120 milliseconds with inverted p wave then in such case we call it as ectopic atrial rhythm right we call it as ectopic atrial rhythm now let me show you that particular ecg strip as well that is so if you take this ecg strip you can make out that the p wave is inverted here and the pr interval if you calculate it is more than or equal to 120 milliseconds so this we call it as ectopic atrial rhythm right this we call it as ectopic atrial rhythm all right now followed by that in certain ecgs you will not have p wave at all let me show you the ecg so if you see this ecg there is no p wave at all right there is no p wave now when there is no p wave what does it tells you it tells that the impulse is originating from the av node but not the ac node right it tells that the impulse is originating at the av node but not at the ac node so when the impulse originates at the av node it moves retrogradely and it moves anterogradely and the impulse which is generated or the wave of depolarization which is generated due to anti-grade direction where it will depolarize the ventricle that particular depolarization wave will neutralize the depolarization wave of the atrial origin right that will neutralize the depolarization wave of the atrial origin or it will mask the p wave so that is the reason why you don't have the p wave so remember if there is no p wave it tells you it is a junctional rhythm so to summarize everything now if there is inverted p wave it is non-sinus origin that means it is not originating from the sa node and along with that if the pr interval is less than 120 milliseconds junctional rhythm if the pr interval is more than 120 milliseconds it is ectopic atrial rhythm and if there is no p wave it is your junctional rhythm right now now after having discussed about the various p wave abnormalities in the form of inverted p wave now let me discuss variable morphologies of the p wave right you see this question so the question is treatment to be given for this patient suffering with the copd cardioversion metaprolol verapamil amirone so the answer to this question is vera pamel first of all what is this ecg right so if you take this ecg here you have right if you just closely observe the p waves you have variable p wave of morphologies right all the p waves they are not of similar morphology they are of variable p wave morphologies now and upon that if you see the rate the heart rate it is more than 100 right the heart rate it is more than 100 per minute now we have a clinical entity called as right we have a clinical entity called as multifocal atrial tachycardia that is called mat now what is the criteria for mac there should be more than or equal to three different p waves right there should be more than or equal to three different p wave morphologies and along with that the heart rate it should be more than 100 per minute that is what is called as multifocal atrial tachycardia and we have one more terminology called multifocal atrial rhythm this is multifocal atrial tachycardia this multifocal atl tachycardia it is more common in copd patients and in copd patients right we usually avoid the beta blockers right we usually avoid the beta blockers so that is the reason why the alternative drug that can be given is calcium channel blocker that is verapamil can be given so this is the ecg of matt multifocal atrial tachycardia now let me show you a ecg of multifocal atrial rhythm that is so you see this ecg here what is that you are observing you are having different p wave morphologies right you are having different p wave morphologies but heart rate if you see right heart rate if you see it is less than hundred this is called as a multifocal atrial rhythm now the question is why do they have this variable p wave morphologies the presence of multiple p wave morphologies indicates that multiple ectopic pacemakers that means the impulse within the atria is not just originating only at the sa node it is originating at multiple sites within the atria and that is the reason why you are having multiple p wave morphologies right you see this image right so here you can make out that this is one particular site this is another side this is another side this is another side so like this multiple sites they are throwing the impulses and that is what is responsible for your variable p wave morphologies so here in multifocal atrial tachycardia sa node is not facing the heart right sa node is not facing the heart there are several groups of excitable cells in the atria that compete to paste the heart so it is several groups of excitable cells that is what i have shown you here right so these are all your several groups of the excitable cells right in mat as already have said you there should be at least three different p wave morphologies and the heart rate should be above 100 beats per minute and in case of math remember there is irregular pr interval irregular rr interval irregular pp interval so the rhythm in math it is an irregular rhythm right rhythm in the mat it is an irregularity now the other points are what are the clinical manifestations in patients with the mat so if you take the clinical manifestations remember very important because they have tachycardia palpitations is one of the very important clinical manifestations right and apart from palpitations if you take the blood pressure or of these individuals it will be on the lower side because there is like tachycardia heart rate is very high and it is like improper contractions they are not like complete contractions and that is the reason why the cardiac output also will be reduced so due to which they can have light headedness right due to which they'll have light headedness and they will also have syncopal attacks right they have syncopal attacks and on examination there is presence of low blood pressure and they will have tachycardia right and ecg it will show the features of mat which just now i have discussed and how do you treat these patients i said you copd is the most common risk factor so you need to manage the respiratory failure right you need to manage the respiratory failure cardioversion may not be helpful due to hypoxia and the treatment include beta blockers and these beta blockers examples are metoprolol and calcium channel blockers are given and this particular calcium channel blockers include vera pamela right these calcium channel blockers include the vera pamela okay so metaprolol and as well as the vera pamela these are the drugs that can be given in the treatment of patients with a mat and even for recurrent episodes right even for the recurrent episodes we give calcium channel blockers that verapamil is given right varapamil is given orally to prevent the further episodes right to prevent the further episodes and not only that you should also know what are the etiologies of the mat that is so if you see this question drug causing mat degoxin toxicity theophilian toxicity atropinization opioid poisoning remember the drug causing mat is the theophilian toxicity and apart from that copd as already i have said you that is the most common cause right copd is the most common cause and what is the mechanism copd will cause hypoxia and as well as the hypercarbia right so this hypoxia and hypercarbia is the one which will cause the multifocal atrial tachycardia and apart from that sepsis right apart from that sepsis so sepsis is another important cause for the development of multifocal atrial tachycardia okay next now the other important thing like what you need to understand is about the atrial extra system right atrial extra system let me show you that ecg so if you take this ecg this is the ecg of atrial extra systole right now why are you calling it as atrial extra systole now you take this this is the normal p wave normal p wave normal p wave and normal p wave but before the appearance of the next complex you have one more complex with abnormal p wave and here also the same thing before the appearance of the next normal complex there is appearance of another complex with abnormal p wave and this is nothing but your atrial extra systole or atrial premature contracture right atrial premature contracture or atrial premature complex right so let me show you the ecg also right let me show you the example i mean the multiple choice question as well comment on the ecg finding atrial fibrillation atrial premature contractures paroxysmal supraventricular tachycardia wpw syndrome so if you see here this is your normal p wave normal p wave normal p wave normal p wave but you see here these two complexes you are having the abnormal p waves and these abnormal p waves they are appearing earlier than the next normal complex so it is a atrial premature complex and the same way i will show you the ecgs of the other options as well but in this option the ecg it is suggestive of the atrial premature complex right next after having discussed about this now i let me explain you about the atrial premature complex like why are you having a complex earlier than the normal so if you see the mechanism this atrial premature complex it is nothing but it is your ectopic pacemaker right it is your ectopic focus and as well as the ectopic pacemaker so what is happening here is normally the impulse has to originate from the sa node but here in case of the ectopic pacemakers right but here in case of the ectopic pacemakers the impulse is originating apart from the snow right the impulse is originating apart from the sa node as well so that is your ectopic pacemaker now these ectopic pacemakers what they can do is they can send the impulse to the av node earlier than the snow when the ectopic pacemaker sends the impulse to the av node earlier than the sa nodal impulse that is the point when you will have this premature atrial complex right if the ventricle contracts secondary to your atrial ectopics then in such case you will have abnormal p wave but normal qrs complex why normal qr is complex because the ventricle depolarization is through your normal conducting system that is your bundle office right and left bundle branch but the atrial depolarization is not through the ac node the adrenal depolarization is through your ectopic pacemaker and that is the reason why you will have this abnormal p wave now let me show you ecgs of the other options as well now you take the atrial fibrillation and this is the ecg of the atrial fibrillation so in atrial fibrillation what is that you will have is number one you will have irregular rhythm right so if you see there the rhythm is irregularity that is why because you have variable rr interval and you don't have the p wave this is not your p wave what are these waves called these are called as the fibrillatory waves right these are called as the fibrillatory waves so this is the ecg of the atrial fibrillation and similarly one more option was your psvt that is peroxismal supraventricular tachycardia now if you see this ecg here you are having the tachycardia so you can make out there and the heart rate is nearly around 250 per minute or more than that and if you take the complexes the qrs complexes they are like narrow complexes so this is the ecg off narrow complex tachycardia right this is the ecg of narrow complex tachycardia now where is your p wave in this remember in examples of your narrow complex tachycardia one of the example is psvt paroxysmal supraventricular tachycardia in paroxysmal supraventricular tachycardia the p wave either it merges with the qrs complex or it appears after the qrs complex right depending upon the subtypes of psvt which we will be discussing in detail in ardhamyas separately okay so in case of peroxism supraventricular tachycardia you will have narrow complex tachycardia now at this juncture you should also know how will be the ecg of the atrial flucture right so if you see this ecg you are having the p wave as right you are having a p wave as sawtooth pattern so this sort of pattern p wave where is that you will have you will have this in patience with the atrial flutter right anyways i'll be discussing again in detail about the atrial fibrillation atrial flutter peroxism supraventricular tachycardia in the topic of the arrhythmias but here what i wanted to show you is variable p wave morphologies i wanted to show you when i am discussing the p wave abnormality right now the last question on the p wave right so the question here is pseudo p pulmonal is seen in hypokalemia hypocalcemia hyperkalemia hypomagnesemia so remember the pseudo p pulmonal it is seen in patients with the hypokalemia right in hypokalemia let me show you all the ecg changes right that is if you take this is the ecg changes in hypokalemia that is so this is your normal ecg complex the first one and gradually if you observe there will be flattening of the t wave right and finally there can be also inverted t wave as well so the first appearance is flattening of the t wave and there will be also appearance of the u wave and subsequently you can observe that there is st segment depression and subsequently you can also observe the qt interval being prolonged and apart from that very important you take the p wave right so you are having the p wave which is sharp and amplitude is also increased compared to that of the normal p wave and this is what is called as pseudo p wave or pseudo p pulmonal right this is called pseudo p palm nail now remember the true p pulmonal you will have that in patients with the tricuspid stenosis pulmonary stenosis pulmonary hypertension carpal nail tetralogy of fallow but pseudo people male is seen in patients with a hypokalemia so this is about your p wave abnormalities so we have discussed the p wave in right and left atrial enlargement and depending upon the p wave morphology we can decide the rhythm that is multifocal atrial tachycardia and as well as we will also be able to decide the ectopic pacemakers right that is multifocal atrial rhythm and then based on the p wave morphology we can decide atrial fibrillation and as well as the atrial flutter and lastly one important point related to your pseudo p pulmonary so these are the points what you need to know about the p wave abnormalities thank you very much

Channel: Dr.G Bhanu Prakash Animated Medical Videos

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Keywords: p wave, p wave inversion, inverted p waves, bifid p wave, normal p wave, p waves, p wave morphology, absent p wave, p wave abnormalities, normal p waves, ekg p waves normal, p waves basic, p wave basics, peaked p wave, p wave -ve, p mitrale, p pulmonale, p wave ecg, p wave represents, p mitrale ecg, biphasic p wave, p wave ecg abnormalities, prolonged p wave, normal p wave duration, p wave duration, the p wave represents, in ecg p wave represents, ecg basics, ecg, ekg

Id: lQMSkSdm8kU

Length: 56min 44sec (3404 seconds)

Published: Sat May 28 2022