Clinical Disorders: Difference between revisions

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{{authors|
{{authors|
|mainauthor= I.A.C. van der Bilt, MD  
|mainauthor= [[user:Vdbilt|I.A.C. van der Bilt, MD]]
|coauthor=
|moderator= [[T.T. Keller]]
|moderator= I.A.C. van der Bilt, MD
|supervisor=
|editor= [[user:Drj|J.S.S.G. de Jong, MD]]
}}
}}


==Medication==
==Medication==
===Digoxin===
===Digoxin===
[[Image:med_digitalis.png|thumb|Typical for digoxin intoxication is the odd shaped ST-depression]]
[[Image:med_digitalis.png|thumb|300px|Typical for digoxin intoxication is the oddly shaped ST-depression]]
ECG changes typical for digoxin intoxication (digoxin = Lanoxin) are:
ECG changes typical for digoxin '''use''' (digoxin = Lanoxin) are:
*odd shaped ST-depression.
*Oddly shaped ST-depression with 'scooped out' appearance of the ST segment (see figure)
*T-wave flat, negative or biphasic
*Flat, negative or biphasic T wave
*Short QT interval
*Short QT interval
*Increased u-wave amplitude
*Increased u-wave amplitude
*Prolonged PR-interval
*Prolonged PR-interval
*Brady-arrhytmias:
*Sinus bradycardia
**Sinusbradycardia
ECG changes typical for digoxin '''intoxication''' are:
*Bradyarrhythmias:
**AV block. Including complete AV block and Wenkebach.
**AV block. Including complete AV block and Wenkebach.
*Tachyarrhythmias:
*Tachyarrhythmias:
**Junctional tachycardia
**Junctional tachycardia
**Atrialtachycardia
**Atrial tachycardia
**Ventricular ectopia, bigemini, monomorphic ventricular tachycardia, bidirectional ventricular tachycardia
**Ventricular ectopia, bigemini, monomorphic ventricular tachycardia, bidirectional ventricular tachycardia


Intoxication can lead to a SA-block or AV-block, sometimes in combination with a tachycardia. '''NB''' these effects are increased by hypokaliemia. In extreme high concentrations rhythmdisturbances (''ventricular tachycardia, ventricular fibrillation, atrial fibrillation'') may develop.
Intoxication can lead to an SA-block or AV-block, sometimes in combination with tachycardia. '''NB''' these effects are increased by hypokalemia. In extreme high concentrations rhythm disturbances (''ventricular tachycardia, ventricular fibrillation, atrial fibrillation'') may develop.
{{clr}}


===Anti-arhythmics===
===Antiarrhythmics===
* '''anti-arhythmics:''' These may lead to several ECG-changes;
* '''Anti-arrhythmics:''' These may lead to several ECG-changes;
**broad and irregulair P-wave
**Broad and irregular P-wave
**broad QRS-complex
**Broad QRS complex
**prolonged QT-interval (brady-, tachycardia, AV-block, ventricular tachycardia)
**Prolonged QT interval (brady-, tachycardia, AV-block, ventricular tachycardia)
**prominent U-wave
**Prominent U-wave
**In case of intoxication, the above mentioned characteristics are more prominent
**In case of intoxication, the above mentioned characteristics are more prominent


Additionally, several arrhtythmias can be seen.
Additionally, several arrhthytmias can be seen.
===Beta blockers===
[[File:E000542.jpg|thumb|right|ECG of a patient with atenolol intoxication]]Beta blocker intoxication can result in bradycardia, hypotension, QRS widening and seizures. In a series of 260 patients with beta blocker intoxication, 41 (15%) developed cardiovascular morbidity and 4 (1.4%) died. Cardioactive coingestant (e.g. calcium channel blockers) was the only factor significantly associated with the development of cardiovascular morbidity. <cite>bb</cite>
{{clr}}


=== Nortriptyline intoxication ===
=== Nortriptyline Intoxication ===
[[Image:ECG_nortr_intox.png|thumb| An example of severe nortriptyline intoxication. The inhibitory effect of the sodiumchannel manifests as a broadened QRS complex and a prolonged QT interval.]]
<div align="center">
{|
|
[[Image:ECG_nortr_intox.png|thumb|left|300px|An example of severe nortriptyline intoxication. The inhibitory effect on the sodium channel manifests as a broadened QRS complex and a prolonged QT interval.]]
|
[[Image:ECG_TCA_intox.jpg|thumb|left|300px| Another example of severe nortriptyline intoxication.]]
{{clr}}
{{clr}}
 
|}
=== Amitriptyline intoxication ===
</div>
[[Image:ECG_amitr_OD_during.jpg|thumb| An example of a severe amitriptylin intoxication. The inhibitory effect of the sodiumchannel manifests as a broadened QRS complex.]]
=== Amitriptyline Intoxication ===
[[Image:ECG_amitr_OD_before.jpg|thumb| An ECG of the same patient before the intoxication.]]
<div align="center">
 
{|
|
[[Image:ECG_amitr_OD_during.jpg|thumb|300px| An example of a severe amitriptyline intoxication. The inhibitory effect on the sodium channel manifests as a broadened QRS complex.]]
|
[[Image:ECG_amitr_OD_before.jpg|thumb|300px| An ECG of the same patient before the intoxication.]]
|}
</div>
{{clr}}
{{clr}}


==Pericarditis==
==Pericarditis==
[[Image:Stadia_pericarditis.png|thumb| Several stages of pericarditis]]
[[Pericarditis]]
[[w:Pericarditis|Pericarditis]] is an inflammation of the pericardium. This can lead to ST elevation in all leads. Therefore, it is important to distinguish pericarditis from a myocardial infarction, which has more acute complaints and ST-elevations are limited to the infarct area.


In pericarditis four stages can be used:
==Myocarditis==
*stage I:   ST elevation in all leads. PTa depression (depression between the end of the P-wave and the beginning of the QRS- complex)
[[File:E000535.jpg|thumb|A patient with myocarditis and pericarditis showing diffuse ST elevation]]
*stage II:  pseudonormalisation (transition)
[[w:Myocarditis|Myocarditis]] is an inflammation of the myocardium and the interstitium. The symptoms are faint chest pain, abnormal heart rate and progressive heart failure. It can be caused by several factors: viruses, bacteria, fungi, parasites, spirochetes, auto-immune reactions, borreliosis (Lyme's disease) and HIV/AIDS.
*stage III:  inverted T-waves
*stage IV:  normalisation


Keep into account that in stage I pericarditis, ST-elevation is present in all leads except in aVR, V1 and III.
Acute peri/myocarditis causes nonspecific ST segment changes. These can be accompanied by supraventricular and ventricular rhythm disturbances and T-wave abnormalities.
{{clr}}
{{clr}}


==Myocarditis==
==Pulmonary Embolism==
See the chapter [[Pulmonary Embolism]]


[[w:Myocarditis|Myocarditis]] is an inflammation of the myocardium and the interstitium. The symptoms are faint chestpain, abnormal heartrate and progressive heartfailure. It can be caused by several factors: viral, bacterial, fungi, parasites, spirochaet, auto-immune, borreliosis (Lyme's disease) and HIV/AIDS.
==Chronic Pulmonary Disease Pattern==
 
[[File:E000004.jpg|thumb|right|An example of right ventricular hypertrophy (and right atrial enlargement) in a patient with chronic pulmonary hypertension due to peripheral embolisation.]]The ECG shows low voltage QRS complexes in leads I, II, and III and a right axis deviation. This is caused by the increased pressure on the right chamber. This leads to right ventricular hypertrophy.
Acute peri/myocarditis causes aspecific ST changes. These can be accompanied with supraventricular and ventricular rhythmdisturbances and T-wave abnormalities.
{{clr}}
 
==Pulmonary embolism==
[[Image:Pulm_embolism.jpg|thumb|ECG of a patiënt with pulmonary embolism]]
In case of a [[w:Pulmonary_embolism|pulmonary embolism]] several clinical features may be present:<cite>Rodger</cite>
* Sinustachycardia
* Stress on the right ventricle:
**[[Chamber_Hypertrophy_and_Enlargment#Right_atrial_enlargement|right atrial dilatation]]
**Heartaxis is to the right
**[[RBBB|Right bundlebranchblock]]
* Deep S in I
* Q and negative T in III
* T wave inversion anterior <cite>Ferrari</cite>
 
Pulmonary embolism cannot solely be diagnosed using an ECG, but it may be helpful.
 
==Chronic pulmonary disease pattern==
The ECG shows low voltaged QRS-complexes in leads I, II, and III and a right axisdeviation. This is caused by the increased pressure on the right chamber. This leads to right ventricular hypertrophy.


==Pacemaker==
==Pacemaker==
Line 85: Line 81:


==Tamponade==
==Tamponade==
In case of a tamponade, fluid collects in the pericardium. The pericardium is stiff and the heart cannot pump, because it cannot relax as well. The ECG shows:
[[Image:ECG000028.jpg|thumb|Electrical alternans on the ECG]]
In case of tamponade, fluid collects in the pericardium. Because the pericardium is stiff, the heart is compressed, resulting in filling difficulties. This is a potentially life-threatening situation and should be treated with pericardiocentesis, drainage of the fluid. Tamponade can be the result of pericarditis or myocarditis. After a myocardial infarction a tamponade can also develop; this is called Dresslers' Syndrome. In case of cancer,increased pericardial fluid may develop. This is usually caused by pericarditis carcinomatosis, meaning that the cancer has spread to the pericardium
 
The ECG shows:
*Sinus tachycardia
*Sinus tachycardia
*Low-voltaged QRS complexes [[microvoltages]]
*Low-voltage QRS complexes [[microvoltages]]
*Alternation of the QRS complexes, usually in a 2:1 ratio. Electrical alternans can also be seen in myocardial ischemia, acute pulmonary embolism, and tachyarrhythmias
*Alternation of the QRS complexes, usually in a 2:1 ratio. Electrical alternans can also be seen in myocardial ischemia, acute pulmonary embolism, and tachyarrhythmias
*PR segment depression (this can also be observed in an [[Ischemia#Atriaal_.2F_boezem_infarct|atrial infarction]])
*PR segment depression (this can also be observed in an [[Ischemia#Atriaal_.2F_boezem_infarct|atrial infarction]])
{{clr}}


==Ventricular Aneurysm==
==Ventricular Aneurysm==
The ECG pattern suggests an acute MI. All classical signs of MI may occur:; Q-waves, ST-elevations (>1mm, >4 weeks present)and T-wave inversions are present. To exclude an acute MI, comparison with old ECG's is compulsory (MI has occurred years before).
The ECG pattern suggests an acute MI. All classical signs of MI may occur:; Q waves, ST segment elevations (>1mm, >4 weeks present)and T wave inversions are present. To exclude an acute MI, comparison with old ECG's is compulsory (MI has occurred years before).


==Dilated Cardiomyopathy==
==Dilated Cardiomyopathy==
Often, a LBBB or broadened QRS-complex can be seen. Additionally, aspecific ST changes are present with signs of left atrial enlargement.
Often, a LBBB or broadened QRS-complex can be seen. Additionally, nonspecific ST segment changes are present with signs of left atrial enlargement.


==Hypertrophic Obstructive Cardiomyopathy==
==Hypertrophic Obstructive Cardiomyopathy==
A HOCM is an heditary illness.
A HOCM is a hereditary illness.
On the ECG there are signs of [[hypertrophy|left ventricular hypertrophy]] and [[P wave morphology|left atrial enlargement]].
On the ECG there are signs of [[hypertrophy|left ventricular hypertrophy]] and [[P wave morphology|left atrial enlargement]].


==Electrolyte disturbances==
==Electrolyte Disturbances==
See chapter: [[electrolyte disturbances]]
See chapter: [[electrolyte disturbances]]


==Hypothermia==
==Hypothermia==
In hypothermia a number of specific chnages can be seen;
[[Image:osborne.png|thumb|left|250px| An Osborn J wave]]
* sinubradycardia
[[Image:Osborn-wave.gif|thumb|left|250px|Osborn wave.  81-year-old black male with BP 80/62 and temperature 89.5 degrees F (31.94 C).]]
* prolonged QTc-interval
<div style="float:right">
* ST-elevation (inferior and left precordial leads)
<gallery>
* Osborne-waves (slow deflexions at the end of the QRS-complex)
Image:osborne_ecg.jpg|A 12 lead ECG of a patient with a body temperature of 32 degrees Celsius. Note the sinus bradycardia, the prolonged QT interval (QTc is not prolonged) and the Osborn J wave, most prominently in leads V2-V5
Image:JJ0001.jpg|An ECG of a patient with a body temperature of 28 degrees Celsius.
</gallery>
</div>
In hypothermia a number of specific changes can be seen;<cite>hypoth</cite>
* Sinus bradycardia
* Prolonged QTc-interval
* ST segment elevation (inferior and left precordial leads)
* Osborn-waves (slow deflections at the end of the QRS-complex)


[[Image:osborne.gif|thumb| An Osborne J wave]]
{{clr}}
{{clr}}


==ECG changes after neurologic events==
==ECG Changes after Neurologic Events==
[[Image:ECG_SAB.png|thumb| ECG of a 74 year old patient with a subarachnoid hemorrhage. Note the negative T-waves and the prolonged QT interval.]]
[[Image:ECG_SAB.png|thumb| ECG of a 74 year old patient with a subarachnoid hemorrhage. Note the negative T-waves and the prolonged QT interval.]]
In 1938, Aschenbrenner <cite>Aschenbrenner</cite> noted that repolarisation abnormalities may occur after increased intracranial pressure. Since then, many publications have occurred discribing ECG changes after acute neurological events.
In 1938, Aschenbrenner <cite>Aschenbrenner</cite> noted that repolarization abnormalities may occur after increased intracranial pressure. Since then, many publications have described ECG changes after acute neurological events.


De ECG changes that may occur are:  
ECG changes that may occur are:  
*q-waves
*Q waves
*ST-elevations,  
*ST segment elevations,  
*ST-depressions,  
*ST segment depressions,  
*T-wave changes. Large negative T waves over the precordial leads are observed frequently.
*T wave changes. Large negative T waves over the precordial leads are observed frequently.
*prolonged QT-interval.
*Prolonged QT-interval.
*prominent u-waves.
*Prominent u-waves.


These abnormalites are frequently seen after [[w:Subarachnoid_hemorrhage|subarachnoid_hemorrhage (SAH)]] (if measured serially, almost every SAH patients has at least one abnormal ECG.), but also in [[w:Subdural_haematoma|subdural haematoma]], ischemic [[w:Cerebrovascular_accident|CVA]]'s, [[w:Brain_tumor|brain Tumors]], [[w:Guillain-Barre|Guillain Barré]], [[w:Epilepsy|epilepsy]] and [[w:Migraine|migraine]]. The ECG changes are generally reversible and have linited prognostic value. However, the ECG changes can be accompanied with myocardial damage and echocardiographic changes. The cause of the ECG changes is not yet cl;ear. The most common hypothesis is that of a neurotramittor "catecholaminestorm" caused by sympathtic stimulation.
These abnormalities are frequently seen after [[w:Subarachnoid_hemorrhage|subarachnoid_hemorrhage (SAH)]] (if measured serially, almost every SAH patients has at least one abnormal ECG.), but also in [[w:Subdural_hematoma|subdural hematoma]], ischemic [[w:Cerebrovascular_accident|CVA]]'s, [[w:Brain_tumor|brain Tumors]], [[w:Guillain-Barre|Guillain Barré]], [[w:Epilepsy|epilepsy]] and [[w:Migraine|migraine]]. The ECG changes are generally reversible and have limited prognostic value. However, the ECG changes can be accompanied with myocardial damage and echocardiographic changes. The cause of the ECG changes is not yet clear. The most common hypothesis is that of a neurotramitter "catecholamine storm" caused by sympathetic stimulation.


==Cardiac contusion==
==Cardiac Contusion==
Cardiac contusion (in latin: contusio cordis or commotio cordis) is caused by a blunt trauma to the chest, often caused by a car- or motorbikeaccident or in martial arts<cite>Maron</cite>. Rhythmdisturbances may occur and even heartfailure. Diagnosis is made using echocardiography and laboratorytesting for cardiac enzymes.  
Cardiac contusion (in latin: contusio cordis or commotio cordis) is caused by a blunt trauma to the chest, often caused by a car or motorbike accident or in martial arts<cite>Maron</cite>. Rhythm disturbances and even heart failure can occur. Diagnosis is made using echocardiography and laboratory testing for cardiac enzymes.  
Possible ECG changes are:<cite>Sybrandy</cite>
Possible ECG changes are:<cite>Sybrandy</cite>


'''Not-specific changes'''
'''Nonspecific changes'''
*Pericarditis-like ST elevation or PTa depression
*Pericarditis-like ST elevation or PTa depression
*Prolonged QT interval
*Prolonged QT interval
Line 139: Line 146:
*ST-T segment elevation or depression
*ST-T segment elevation or depression
'''Conduction delay'''
'''Conduction delay'''
*Right bundelbranchblok
*Right bundle branch block
*Fascicular blok
*Fascicular blok
*AV delay(1st, 2nd, and 3rd degree AV blok)
*AV delay(1st, 2nd, and 3rd degree AV blok)
'''Arrhythmias'''
'''Arrhythmias'''
*Sinustachycardia
*Sinus tachycardia
*Atrial and ventricular extrasystoles
*Atrial and ventricular extrasystoles
*Atrial fibrillation
*Atrial fibrillation
*Ventricular tachycardia
*Ventricular tachycardia
*[[Arrhythmias#Ventricular fibrillation|Ventricular fibrillation]]
*[[Arrhythmias#Ventricular fibrillation|Ventricular fibrillation]]
*Sinusbradycardia
*Sinus bradycardia
*Atriala tachycardia
*Atrial tachycardia


==Lown Ganong Levine Syndrome==
==Lown Ganong Levine Syndrome==
The Lown Ganong Levine Syndrome is a pre-excitation syndrome in which the atria are connected to the lower part of the AV node or bundle of His. On the ECG:
The Lown Ganong Levine Syndrome is a pre-excitation syndrome in which the atria are connected to the lower part of the AV node or bundle of His. On the ECG:
* short PR interval, < 120 ms
* Short PR interval, < 120 ms
* normal QRS complex
* Normal QRS complex
* no delta wave
* No delta wave
==Left and right bundelbranch block==
==Ebstein==
[[File:E000403.jpg|thumb|300px|ECG from a patient with Ebstein's anomaly showing huge P waves and low amplitude QRS waves. RBBB and T wave inversion are not present on this ECG.]]
In Ebstein anomaly the tricuspid valve is inserted more apically than normal. This yields a very large right atrium. About 50% of individuals with Ebstein's anomaly have evidence of Wolff-Parkinson-White syndrome, secondary to the atrialized right ventricular tissue.
 
Other abnormalities that can be seen on the ECG include
#signs of right atrial enlargement or tall and broad 'Himalayan' P waves,
#first degree atrioventricular block manifesting as a prolonged PR-interval
#low amplitude QRS complexes in the right precordial leads
#atypical right bundle branch block
#T wave inversion in V1-V4 and Q waves in V1-V4 and II, III and aVF.
#Q waves in II, III, AVF. These Q waves are thought to reflect fibrotic thinning of the right ventricular free wall and/or septal fibrosis with coexisting left posterior hemiblock<cite>khairy</cite>
{{clr}}
 
==Left and right bundle branch block==
See: [[Conduction_delay|Conduction delay]]
See: [[Conduction_delay|Conduction delay]]


==Cocaine Intoxication==
|<!--col1-->[[Image:JJ00001.jpg|200px]]
==Sarcoidosis==
In patients with proven pulmonary sarcoidosis ECG changes can be used as a marker of cardiac involvement. Presence of a fractionated QRS or a Bundle Branch Block increases the likelihood of cardiac involvement.<cite>schuller</cite>
{{Box|
==References==
==References==
<biblio>
<biblio>
Line 164: Line 192:
#Rodger pmid=11018210
#Rodger pmid=11018210
#Ferrari pmid=9118684
#Ferrari pmid=9118684
#Aschenbrenner Aschenbrenner R, Bodechtel G, ''Über Ekg.-Veränderungen bei Hirntumorkranken''. Journal of Molecular Medicine, 17, 9, 2/1/1938, Pages 298-302, http://dx.doi.org/10.1007/BF01778563
#Aschenbrenner Aschenbrenner R, Bodechtel G, ''Über Ekg.-Veränderungen bei Hirntumorkranken''. Journal of Molecular Medicine, 17, 9, 2/1/1938, Pages 298-302, http://dx.doi.org/10.1007/BF01778563
#Maron pmid=14681516
#Maron pmid=14681516
#hypoth pmid=2738372
#khairy pmid=18056539
#schuller pmid=21615816
#bb pmid=10866327
</biblio>
</biblio>
<analytics uacct="UA-807577-6"></analytics>
}}
[[Category:ECG Textbook]]

Latest revision as of 02:26, 31 May 2012

Author(s) I.A.C. van der Bilt, MD
Moderator T.T. Keller
Supervisor
some notes about authorship

Medication

Digoxin

Typical for digoxin intoxication is the oddly shaped ST-depression

ECG changes typical for digoxin use (digoxin = Lanoxin) are:

  • Oddly shaped ST-depression with 'scooped out' appearance of the ST segment (see figure)
  • Flat, negative or biphasic T wave
  • Short QT interval
  • Increased u-wave amplitude
  • Prolonged PR-interval
  • Sinus bradycardia

ECG changes typical for digoxin intoxication are:

  • Bradyarrhythmias:
    • AV block. Including complete AV block and Wenkebach.
  • Tachyarrhythmias:
    • Junctional tachycardia
    • Atrial tachycardia
    • Ventricular ectopia, bigemini, monomorphic ventricular tachycardia, bidirectional ventricular tachycardia

Intoxication can lead to an SA-block or AV-block, sometimes in combination with tachycardia. NB these effects are increased by hypokalemia. In extreme high concentrations rhythm disturbances (ventricular tachycardia, ventricular fibrillation, atrial fibrillation) may develop.

Antiarrhythmics

  • Anti-arrhythmics: These may lead to several ECG-changes;
    • Broad and irregular P-wave
    • Broad QRS complex
    • Prolonged QT interval (brady-, tachycardia, AV-block, ventricular tachycardia)
    • Prominent U-wave
    • In case of intoxication, the above mentioned characteristics are more prominent

Additionally, several arrhthytmias can be seen.

Beta blockers

ECG of a patient with atenolol intoxication

Beta blocker intoxication can result in bradycardia, hypotension, QRS widening and seizures. In a series of 260 patients with beta blocker intoxication, 41 (15%) developed cardiovascular morbidity and 4 (1.4%) died. Cardioactive coingestant (e.g. calcium channel blockers) was the only factor significantly associated with the development of cardiovascular morbidity. [1]


Nortriptyline Intoxication

An example of severe nortriptyline intoxication. The inhibitory effect on the sodium channel manifests as a broadened QRS complex and a prolonged QT interval.
Another example of severe nortriptyline intoxication.


Amitriptyline Intoxication

An example of a severe amitriptyline intoxication. The inhibitory effect on the sodium channel manifests as a broadened QRS complex.
An ECG of the same patient before the intoxication.


Pericarditis

Pericarditis

Myocarditis

A patient with myocarditis and pericarditis showing diffuse ST elevation

Myocarditis is an inflammation of the myocardium and the interstitium. The symptoms are faint chest pain, abnormal heart rate and progressive heart failure. It can be caused by several factors: viruses, bacteria, fungi, parasites, spirochetes, auto-immune reactions, borreliosis (Lyme's disease) and HIV/AIDS.

Acute peri/myocarditis causes nonspecific ST segment changes. These can be accompanied by supraventricular and ventricular rhythm disturbances and T-wave abnormalities.

Pulmonary Embolism

See the chapter Pulmonary Embolism

Chronic Pulmonary Disease Pattern

An example of right ventricular hypertrophy (and right atrial enlargement) in a patient with chronic pulmonary hypertension due to peripheral embolisation.

The ECG shows low voltage QRS complexes in leads I, II, and III and a right axis deviation. This is caused by the increased pressure on the right chamber. This leads to right ventricular hypertrophy.


Pacemaker

See the chapter Pacemaker

Tamponade

Electrical alternans on the ECG

In case of tamponade, fluid collects in the pericardium. Because the pericardium is stiff, the heart is compressed, resulting in filling difficulties. This is a potentially life-threatening situation and should be treated with pericardiocentesis, drainage of the fluid. Tamponade can be the result of pericarditis or myocarditis. After a myocardial infarction a tamponade can also develop; this is called Dresslers' Syndrome. In case of cancer,increased pericardial fluid may develop. This is usually caused by pericarditis carcinomatosis, meaning that the cancer has spread to the pericardium

The ECG shows:

  • Sinus tachycardia
  • Low-voltage QRS complexes microvoltages
  • Alternation of the QRS complexes, usually in a 2:1 ratio. Electrical alternans can also be seen in myocardial ischemia, acute pulmonary embolism, and tachyarrhythmias
  • PR segment depression (this can also be observed in an atrial infarction)


Ventricular Aneurysm

The ECG pattern suggests an acute MI. All classical signs of MI may occur:; Q waves, ST segment elevations (>1mm, >4 weeks present)and T wave inversions are present. To exclude an acute MI, comparison with old ECG's is compulsory (MI has occurred years before).

Dilated Cardiomyopathy

Often, a LBBB or broadened QRS-complex can be seen. Additionally, nonspecific ST segment changes are present with signs of left atrial enlargement.

Hypertrophic Obstructive Cardiomyopathy

A HOCM is a hereditary illness. On the ECG there are signs of left ventricular hypertrophy and left atrial enlargement.

Electrolyte Disturbances

See chapter: electrolyte disturbances

Hypothermia

An Osborn J wave
Osborn wave. 81-year-old black male with BP 80/62 and temperature 89.5 degrees F (31.94 C).

In hypothermia a number of specific changes can be seen;[2]

  • Sinus bradycardia
  • Prolonged QTc-interval
  • ST segment elevation (inferior and left precordial leads)
  • Osborn-waves (slow deflections at the end of the QRS-complex)


ECG Changes after Neurologic Events

ECG of a 74 year old patient with a subarachnoid hemorrhage. Note the negative T-waves and the prolonged QT interval.

In 1938, Aschenbrenner [3] noted that repolarization abnormalities may occur after increased intracranial pressure. Since then, many publications have described ECG changes after acute neurological events.

ECG changes that may occur are:

  • Q waves
  • ST segment elevations,
  • ST segment depressions,
  • T wave changes. Large negative T waves over the precordial leads are observed frequently.
  • Prolonged QT-interval.
  • Prominent u-waves.

These abnormalities are frequently seen after subarachnoid_hemorrhage (SAH) (if measured serially, almost every SAH patients has at least one abnormal ECG.), but also in subdural hematoma, ischemic CVA's, brain Tumors, Guillain Barré, epilepsy and migraine. The ECG changes are generally reversible and have limited prognostic value. However, the ECG changes can be accompanied with myocardial damage and echocardiographic changes. The cause of the ECG changes is not yet clear. The most common hypothesis is that of a neurotramitter "catecholamine storm" caused by sympathetic stimulation.

Cardiac Contusion

Cardiac contusion (in latin: contusio cordis or commotio cordis) is caused by a blunt trauma to the chest, often caused by a car or motorbike accident or in martial arts[4]. Rhythm disturbances and even heart failure can occur. Diagnosis is made using echocardiography and laboratory testing for cardiac enzymes. Possible ECG changes are:[5]

Nonspecific changes

  • Pericarditis-like ST elevation or PTa depression
  • Prolonged QT interval

Myocardial damage

  • New Q waves
  • ST-T segment elevation or depression

Conduction delay

  • Right bundle branch block
  • Fascicular blok
  • AV delay(1st, 2nd, and 3rd degree AV blok)

Arrhythmias

  • Sinus tachycardia
  • Atrial and ventricular extrasystoles
  • Atrial fibrillation
  • Ventricular tachycardia
  • Ventricular fibrillation
  • Sinus bradycardia
  • Atrial tachycardia

Lown Ganong Levine Syndrome

The Lown Ganong Levine Syndrome is a pre-excitation syndrome in which the atria are connected to the lower part of the AV node or bundle of His. On the ECG:

  • Short PR interval, < 120 ms
  • Normal QRS complex
  • No delta wave

Ebstein

ECG from a patient with Ebstein's anomaly showing huge P waves and low amplitude QRS waves. RBBB and T wave inversion are not present on this ECG.

In Ebstein anomaly the tricuspid valve is inserted more apically than normal. This yields a very large right atrium. About 50% of individuals with Ebstein's anomaly have evidence of Wolff-Parkinson-White syndrome, secondary to the atrialized right ventricular tissue.

Other abnormalities that can be seen on the ECG include

  1. signs of right atrial enlargement or tall and broad 'Himalayan' P waves,
  2. first degree atrioventricular block manifesting as a prolonged PR-interval
  3. low amplitude QRS complexes in the right precordial leads
  4. atypical right bundle branch block
  5. T wave inversion in V1-V4 and Q waves in V1-V4 and II, III and aVF.
  6. Q waves in II, III, AVF. These Q waves are thought to reflect fibrotic thinning of the right ventricular free wall and/or septal fibrosis with coexisting left posterior hemiblock[6]


Left and right bundle branch block

See: Conduction delay


Cocaine Intoxication

|JJ00001.jpg

Sarcoidosis

In patients with proven pulmonary sarcoidosis ECG changes can be used as a marker of cardiac involvement. Presence of a fractionated QRS or a Bundle Branch Block increases the likelihood of cardiac involvement.[7]


References

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