ECGs need to be interpreted in the context of the patient from whom they were recorded. You need to learn to appreciate the variations of normality and of the patterns associated with different diseases, and to think about how the ECG can help patient management. Although no book can be a substitute for practical experience, ECG Problems goes a stage nearer the clinical world than books that simply aim to teach ECG interpretation.
It presents clinical problems in the shape of simple case histories, together with the relevant ECG. It then invites the reader to interpret the ECG in the light of the clinical evidence provided, and to decide on a course of action before looking at the answer. Please use the direct link mentioned below to download John R.
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You may send an email to newkrrish gmail. Tags ECG Guide. Labels: ECG Guide. No comments:. Newer Post Older Post Home. Subscribe to: Post Comments Atom. Keep Updating About New Articles. Follow Us. If the link is not responding, kindly inform us through comment section. We will fixed it soon. We highly encourage our visitors to purch ase orig inal books from the respected publishers. What abnormality does it show? Atrial extrasystoles are not a manifestation of cardiac disease, but the atrial tachycardia may be and will need treating on symp- tomatic grounds.
What to do Ensure that there is no other evidence of heart disease. She should stop smoking and avoid alcohol, coffee and tea. A beta-blocker will probably prevent the tachycardia. He had no symptoms, and no abnormalities were detected on physical examination. This ECG was recorded during a routine follow-up appointment. Does it give any cause for concern, and if so, what would you do? This is due to fibrosis, almost certainly the result of long-standing hypertension. It is, therefore, possible that the T wave inversion is due to ischaemia.
An echocardiogram should be recorded to assess his left ventricular thickness and function, because the prognosis is worse if there is left ventricular hypertrophy or if there is any reduction in function. The presence of other risk factors, such as diabetes and hypercholesterolaemia, must be checked and, if necessary, treated. If there is any suggestion of angina, an exercise test should be performed, but if he really is completely asymptomatic this is probably not essential.
Careful control of his blood pressure is the key to management, and since there is evidence of cardiac damage, an angiotensin-converting enzyme inhibitor should be the basis of treatment. What does it show and what would you do? There is nothing on the ECG to suggest a cause for the arrhythmia. What to do When an arrhythmia causes severe heart failure, immediate treatment is more important than establishing the underlying diagnosis.
Carotid sinus pressure and adenosine may increase the degree of block, but are unlikely to convert the heart to sinus rhythm. It is worth trying intravenous flecainide, but a patient with severely compromised circulation is best promptly treated with DC cardioversion. In the long term, ablation therapy to prevent further episodes of atrial flutter may be needed.
Apart from the features associated with pain there are no abnormal physical findings. The rate of development of Q waves is very variable: compare this record with ECG 32, which came from a patient with a similar duration of symptoms. What to do Pain relief must take priority. In the absence of contraindications i. Attacks occur about once per year.
They start suddenly, his heart feels very fast and regular, and he quickly feels breathless and faint. The attacks stop suddenly after a few minutes. There are no abnormalities on examination, and this is his ECG. What would you do? What to do The patient gives a clear story of a paroxysmal tachycardia, and during attacks he feels dizzy, so the circulation is clearly compromised.
The attacks are infrequent, so there is little point in recording an ambulatory ECG. The patient needs immediate referral to an electrophysiologist for ablation of the aberrant conducting pathway.
It shows one abnormality: what is its significance? The partial RBBB is probably not significant. What to do First degree block does not cause any haemodynamic impairment, and by itself is of little significance. However, when a patient has symptoms in this case dizziness which might be due to a bradycardia, there may be episodes of second or third degree block, or possibly Stokes—Adams attacks, associated with a slow ventricular rate.
The appropriate action is therefore to request an ambulatory ECG, recorded over 24 h, in the hope that the patient will have one of her attacks of dizziness during this time. It would then be possible to see whether the dizziness was associ- ated with a change in heart rhythm. First degree block itself is not an indication for permanent pacing or for any other intervention. Although a Q wave is well developed in lead V3, the changes are entirely consistent with the story of pain for 1 h.
What to do This patient needs pain relief with diamorphine. The ECG shows ST segments raised by more than 2 mm in several leads, so he needs immediate percutaneous coronary intervention PCI or thrombolysis once any risk of excessive bleeding has been excluded. This treatment should not be delayed by waiting for a chest X-ray or any other investigations.
Ventricular extrasystoles do not need treating. You find that he has a systolic heart murmur. His ECG and chest X-ray are shown. What is the diagnosis and what do you do next? Clinical interpretation This is the classic ECG appearance of left ventricular hypertrophy. What to do The combination of dizziness on exercise, a systolic murmur, and evidence of left ventricular hypertrophy suggests significant aortic stenosis.
The next step is an See p. He needed an urgent aortic valve replacement. What abnormality does this ECG show and what physical signs would you look for? The ECG cannot be interpreted further. What to do A patient who has chest pain that could be angina, and who has dizziness and syncope on exertion, probably has severe aortic stenosis — this was the case with this woman. There was a loud ejection systolic murmur, best heard at the upper right sternal edge and radiating to both carotids. The diagnosis was con- firmed by an echocardiogram, which showed a gradient across the aortic valve of about mmHg.
A cardiac catheter was necessary to exclude coronary disease. She then had an aortic valve replacement, and made a complete recovery. This is his ECG. What does it show and what treatment is needed? What to do The patient should be treated in the usual way for his acute myocardial infarction, with pain relief and immediate percutaneous coronary intervention PCI or throm- bolysis. Wenckebach second degree block is usually benign when it occurs with an inferior infarction, and although he must obviously be monitored until sinus rhythm with normal conduction returns, temporary pacing is not necessary.
What does it show? There is a beat-to-beat variation in the interval between QRS complexes, with the heart rate speeding up and slowing down. Com- parison of the rate recorded in lead VF with that recorded in lead V3 may give a false impression of a change of rhythm, but the rhythm strip lead II clearly shows the progressive alteration of the R—R interval.
This variation in heart rate relates to respiration and is called sinus arrhythmia, which is normal in young people. Sinus arrhythmia can be distinguished from atrial extrasystoles because in sinus arrhyth- mia the morphology of the P waves is unchanged.
What to do Nothing! What to do This ECG does not meet the conventional criteria for immediate percutaneous coro- nary intervention PCI or thrombolysis, which are raised ST segments or new left bundle branch block. The treatment is pain relief, aspirin, heparin, a beta-blocker and a statin — with PCI as soon as possible.
The immediate outlook is good but the patient should be monitored and the ECG repeated after 1 h to see if ST segment elevation is appearing. He had a heart murmur. What do the ECG and chest X-ray show and what treatment would be appropriate? No further interpretation is possible. What to do This patient has angina, and the chest X-ray suggests aortic stenosis.
LBBB is char- acteristic of severe aortic stenosis. The problem is deciding whether his episode of severe pain is due to a bad attack of angina or to a myocardial infarction. An aortic dissection is also a possibility. Percutaneous coronary intervention PCI or throm- bolytic agents should not be given unless there is evidence from previous records that the LBBB is new, and treatment will depend on whether the plasma troponin level is elevated.
The patient urgently needs an echocardiogram, and probably needs early cardiac catheterization with a view to aortic valve replacement. He will need long-term anticoagulants because of the atrial fibrillation. What might be the diagnosis of the underlying heart condition and what would you do? Clinical interpretation The ventricular rate is not adequately controlled, though the downward-sloping ST segment depression suggests that he is taking digoxin.
The horizontal ST segment depression suggests ischaemia. What to do Despite the ECG evidence of ischaemia, possible diagnoses include rheumatic heart disease, thyrotoxicosis, alcoholic heart disease, and other forms of cardiomyopathy. The chest X-ray suggests severe mitral regurgitation.
Echocardiography is necessary. The serum digoxin level must be checked and the digoxin dose increased if appro- priate. In addition to digoxin, the patient will need an angiotensin-converting enzyme inhibitor, a diuretic and, unless contraindicated, anticoagulants. Beta- blockers must be considered once his cardiac failure is controlled. What does his ECG show, and what would you do? What to do The patient should be given pain relief, and in the absence of the usual contraindica- tions should immediately be treated with aspirin, immediate percutaneous coronary intervention PCI or a thrombolytic agent.
If he was treated with streptokinase for his previous infarction, he should be given alteplase or reteplase on this occasion. He had no symptoms. What does this ECG show and what physical signs would you look for?
The right axis deviation suggests left posterior hemiblock. What to do RBBB is seen in a small proportion of people with otherwise perfectly normal hearts. In the presence of a heart murmur, however, the possibility of an atrial septal defect should be considered.
This is what this patient had. The physical signs were a widely split pulmonary second sound which did not vary with inspiration this is typical of RBBB , and an ejection systolic murmur best heard at the left sternal edge. On deep inspiration a soft diastolic murmur could be heard at the lower left sternal edge. The systolic murmur is a pulmonary flow murmur due to the extra flow through the right side of the heart, and the diastolic murmur that occurs on inspira- tion is a tricuspid flow murmur.
Following opera- tion, the RBBB persisted. He was not aware of a fast heart rate and had had no chest pain. Apart from a rapid rate there were no cardiovascular abnormalities, but he looked a little jaundiced and had an enlarged spleen. What to do Provided the patient is not in heart failure, it is always a good idea to identify the cause of an arrhythmia before treating it.
The combination of an atrial arrhythmia, jaundice and splenomegaly suggests alcoholism. The patient needs anticoagulants, but his INR international normalized ratio may already be high. An echocardio- gram is needed to assess left ventricular function.
Carotid sinus massage will prob- ably increase the degree of atrioventricular block, but is unlikely to correct the arrhythmia. Digoxin, a beta-blocker or verapamil could be given in an attempt to control the ventricular rate. After anticoagulation, cardioversion — either electrical or with flecainide — will be necessary. She had no previous history of breathlessness, and no chest pain. Examination revealed nothing, other than a rapid heart rate.
A pulmonary angiogram was carried out as part of a series of investigations immediately after admission. What is the diagnosis? However, the fact that leads V1—V3 are affected suggests a right ventricular problem. The pulmonary angiogram shows a large central pulmonary embolus and occlu- sion of the arteries to the right lower lung.
Clearly something has happened: the sudden onset of breathlessness without pain suggests a central pulmonary embolus — with pulmo- nary emboli that do not reach the pleural surface of the lung there may be little pain.
In this patient, an echocardiogram and then a pulmonary angiogram demon- strated a large pulmonary embolus. Remember that sudden breathlessness with clear lung fields on a routine chest X-ray is always assumed to be due to a pulmonary embolus until proved otherwise. Heparin is essential; thrombolysis should be considered.
What does the ECG show and how should the patient be treated? Since the T wave inversion is in leads V1—V3 but not V4, the possibility of a pulmonary embolus must be considered. What to do The ECG changes do not meet the conventional criteria for percutaneous coronary intervention PCI or thrombolysis for myocardial infarction raised ST segments or new left bundle branch block , but the patient does need the full range of treatment for an NSTEMI — heparin, aspirin, clopidogrel, a beta-blocker, possibly a nitrate, and a statin.
Early angiography must be considered. First degree block is not an indication for temporary pacing, but the patient must be monitored in case higher degrees of block develop. He is untreated. Does his ECG help with his diagnosis and management? An alternative explanation might be poor lead positioning. What to do The ECG should be repeated, to ensure proper positioning of the chest leads. An echocardiogram and a chest X-ray are needed, to see if left ventricular impairment is responsible for the breathlessness, and stress echocardiography or perfusion imaging are needed, to investigate the chest pain.
The patient was cold, clammy and confused, and his blood pressure was unrecordable. What does the ECG show and what would you do? Here the regularity of the rhythm and the very broad complexes of bizarre configuration leave no room for doubt that this is vent- ricular tachycardia. What to do In cases of severe circulatory failure, immediate DC cardioversion is needed.
The pain is characteristic of a myocardial infarction. Apart from signs due to pain, the examination is normal. The rapidity of Q wave development is extremely variable, but the trace is certainly consistent with a 4 h history. The depressed and downward-sloping ST segment in lead V2 suggests involvement of the posterior wall of the left ventricle.
What to do Pain relief is the most important part of the treatment. In the absence of contra- indications, the patient should be given aspirin immediately, and then percutaneous coronary intervention PCI or thrombolysis as soon as possible.
The appearance of the ECG is characteristic of severe cardiac ischaemia. The lack of a tachycardia is surprising. He needs anticoagulation with aspirin and heparin, though his postoperative state may prevent this, and intravenous nitrates should be given cautiously.
He had not had any chest pain or dizziness. Apart from a slow pulse, there were no abnormalities on examination. What three abnormalities are present in this record and how would you treat the patient? The left axis deviation indicates left anterior hemiblock.
The poor R wave progression virtually no R wave in lead V3, a small R wave in lead V4, and a normal R wave in lead V5 suggests an old anterior infarction. What to do This patient needs a permanent pacemaker. He was worried — should he have been?
There are, however, no T wave changes. The U waves are perfectly normal, and this pattern is common in athletes. What to do Tell the student to buy a good book on ECG interpretation, but if reassurance is not enough, echocardiography could be used to measure the left ventricular thickness. His problem had begun quite suddenly a few weeks previously, when he had had a few hours of dull central chest discomfort.
What do his ECG and the enlarged part of his chest X-ray show and what would you do? Clinical interpretation The raised ST segments suggest an acute infarction, but the deep Q waves suggest that the infarction occurred at least several hours previously.
These ECG changes are therefore probably all old; the anterior changes might indicate a left ventricular aneurysm. Since the ECG is compatible with an old infarction it should be assumed that this diag- nosis is correct, and the patient should be treated for heart failure in the usual way with diuretics, angiotensin-converting enzyme inhibitors and beta-blockers.
Since the heart failure is clearly due to ischaemia he also needs aspirin and a statin. The upper ECG is his record at rest, and the lower one was taken during stage 1 of the Bruce exercise protocol 1. What do these ECGs show and what would you do? Nevertheless, with the story of exercise-induced chest pain a diagnosis of angina seems likely, and an exercise test is the appropriate next step.
Even this light exercise level markedly increased the heart rate. Both the inferior and the anterior chest leads show definite ischaemia, so widespread coro- nary disease is likely, possibly including the main stem of the left coronary artery.
What to do This patient can be treated immediately with short- and long-acting nitrates, beta- blockers and calcium antagonists, but he also needs urgent coronary angiography with a view to percutaneous coronary intervention PCI or coronary artery bypass graft surgery. Risk factors such as smoking, weight and hypercholesterolaemia must See p. His pulse feels irregular but there are no other abnormal signs. This was his ECG. The progressively increasing PR intervals followed by a nonconducted P wave represent second degree block of the Wenckebach Mobitz type 1 type.
The next nonconducted P wave followed by a conducted P wave with a long PR interval is second degree block of Mobitz type 2. The final beat, with the same prolonged PR interval, shows first degree block. The changing heart rate is presumably the cause of his attacks of dizziness. What to do Since this man has had no pain, and there is no evidence of ischaemia on the ECG, it is perhaps unlikely that coronary disease is responsible for the conduction problem.
You should always think about myocarditis, and about infiltrative diseases that might affect the bundle of His, but in a hypertensive patient the most likely cause of this sort of heart block is medication.
He may well be taking either a beta-blocker or a calcium-blocker, and the first thing to do would be to discontinue these. However, the flutter-like activity is variable, and the QRS complexes are completely irregular, so this is atrial fibrillation. The ST segments are normal, with no suggestion of digoxin effect, and the ventricular rate is not controlled, so the patient is probably not taking digoxin. Her thyroid function tests should be checked, and she needs an echocardiogram to assess heart size and left ventricular function.
The heart rate needs to be controlled, and digoxin is the first drug to use. Her heart failure must be treated with a diuretic and probably an angiotensin-converting enzyme inhibitor, and then a decision has to be taken regarding cardioversion. This is unlikely to be successful unless some remediable cause of the atrial fibrillation, such as thyrotoxicosis, is detected.
At this age, she will need life-long anticoagula- tion with warfarin, whatever her echocardiogram shows. Does it help in making a diagnosis? This rhythm is not uncommon, and is usually of no clinical significance.
It is unlikely to be the cause of her symptoms unless at times she has a paroxysmal atrial tachycardia. What to do Take a careful history and attempt to determine whether her symptoms sound like a paroxysmal tachycardia — ask about any sudden onset and ending of the palpita- tions; associated symptoms like breathlessness; precipitating and terminating factors; and so on.
If in doubt, some sort of ambulatory recording will be needed. Any comments? A normal trace would be obtained with the limb leads reversed and the chest leads attached in the usual rib spaces but on the right side of the chest.
What to do Ensure that the leads are properly attached — for example, inverted P waves in lead I will be seen if the right and left arm attachments are reversed. Of course, this would not affect the appearance of the ECG in the chest leads. No previous records are available. Does her ECG help her management? The ECG does not suggest digoxin toxicity, but nevertheless this is the most likely cause of her nausea. The U waves may be normal, but raise the possibility of hypokalaemia.
What to do Digoxin therapy should be temporarily discontinued, and her plasma potassium and digoxin levels should be checked. These are his ECG and chest X-ray: what do they show and what might be the problem? There is upper-zone blood diversion, indicating heart failure. The rhythm change, together with the development of RBBB, could be due to a chest infection but is more likely to have been caused by a pulmonary embolus. The right-sided pleural effusion could also be due to either infection or embolism, but the patient clearly has heart failure because the effusions are bilateral although asymmetrical and there is diversion of blood flow to the upper zones of the lungs.
What to do In a postoperative patient, anticoagulation can always cause haemorrhage. Never- theless, the risk of death from a pulmonary embolus is so high that the patient should immediately be given heparin while steps are taken white blood cell count, sputum culture, CT scan to differentiate between a chest infection and a pulmonary embolus.
The pain had been present for 6 h. What do the ECG and X-ray show and what would you do? Clinical interpretation This ECG shows an acute inferior myocardial infarction, which often causes first degree block.
The Q waves and raised ST segments are consistent with the story of 6 h of chest pain, and the first degree block is not important. What to do Chest pain radiating through to the back has to raise the possibility of aortic dis- section, which can occlude the opening of the coronary arteries and so cause a myocardial infarction. However, this is relatively rare compared with back pain associated with myocardial infarction, which is common.
In this case, the chest X-ray suggests that blood has leaked into the left pleural cavity from a dissection of the aorta. Thrombolysis for the myocardial infarction is obviously contraindi- cated, and the patient needs immediate investigation by CT or MR scanning to see if surgical repair of the dissection is possible.
What does it show and what might be the problem? The extrasystoles are supraventricular because they have the same abnormal QRS pattern as the sinus beats; they are atrial in origin because each is preceded by a T wave of slightly different shape from the sinus beats. What to do The palpitations of which the patient complains may well be due to the extrasys- toles: it is important to ensure that they correspond to her symptoms.
RBBB in a young person may indicate an atrial septal defect, and she should have an echocar- diogram. What does it tell you about the murmur?
The inverted T wave in lead V1 is normal at any age. A normal ECG helps to exclude serious causes of heart murmurs, but the record has not been very helpful in this case. What to do If in doubt, an echocardiogram will show whether there is any important structural abnormality of the heart.
What do you think has happened? The onset of atrial fibrillation may have been the cause or the consequence of the myocardial infarction, and the rapid ventricular rate will at least in part explain the pulmonary oedema. The left anterior hemiblock is probably a consequence of the infarction. The patient may not have experienced pain because of his diabetes.
He needs diamorphine, an intravenous diuretic, intravenous nitrates, and intravenous digoxin to control the ventricular rate — all with careful monitoring. Attention can then be turned to the treatment of his myocardial infarction. He will need anticoagulation with heparin. How would you interpret the ECG and what action would you take? In this patient, the exercise test was perfectly normal, and his symptoms cleared without any intervention.
A repeat ECG, recorded purely out of interest a month later, showed similar changes. What does the ECG show?
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