Dextrocardia

Dextrocardia, (from Latin dexter, meaning "right," and Greek Kardia, meaning "heart") refers to a condition in which the heart is on the right side of the mediastinum. With dextrocardia situs inversus, the heart is a mirror image of its normal position. dextrocardia situs totalis all visceral organs are mirrored. So, if you see a ECG and it looks as if your leads are all reversed, consider that maybe the heart is.

Dextrocardia is a rare condition and occurs in approximately 1 in 12,000 people.

Dextrocardia of embryonic arrest

Is a form of dextrocardia, the heart is simply placed further right in the thorax than is normal, this can be commonly associated with severe defects of the heart and related abnormalities including pulmonary hypoplasia.

Causes of Dextrocardia:

- Kartagener syndrome: Also known as Primary ciliary dyskinesia (PCD). A rare ciliopathic, autosomal recessive genetic disorder that causes defects in the action of cilia lining of the respiratory tract, this is characterized by enlarged bronchial tubes, chronic sinusitis in the lower and upper sinuses, Eustachian tube, middle ear.

- Marden-Walker Syndrome: A rare genetic disorder characterized by blepharophimosis, joint contractures and fixed facial expression.

- Campomelia Cumming type: A rare syndrome characterized by limb and multiple abdominal organ abnormalities. The disorder results in death before birth or soon after.

ECG Features of Dextrocardia 

* Right axis deviation (RAD)

* Positive QRS complexes (with upright P and T waves) in aVR

* Lead I: inversion of all complexes, aka ‘global negativity’ (inverted P wave, negative QRS, inverted T wave)

* Absent R-wave progression in the chest leads (dominant S waves throughout)

Diagram above shows left-sided ECG recorded of a patient with Situs inversus dextrocardia 

Click ECG to enlarge

Differential Diagnosis of Suspected Dextrocardia

Accidental reversal of the left and right arm electrodes may produce a similar picture to dextrocardia in the limb leads (but with normal appearances in the precordial leads).

Diagnosis

This done with either a chest x-ray or 12-lead ECG. .

The chest X-ray below is not reversed, this is a patient with dextrocardia situs inversus showing the cardiac apex facing the right.

Click X-ray to enlarge

Suggested correct lead placement for dextrocardia

ECG study card for dextrocardia

Click study card to enlarge

Things to consider if your patient has dextrocardia and needs pacing/cardioversion or is in cardiac arrest and you have a shockable rhythm.

When defibrillating or pacing the patient with dextrocardia, its is suggested that you place the pads opposite of normal showed in the diagram below. It is suggested that traditional pad placement should be mirrored to the right chest. Anterior/posterior placement should be just right of the mediastinum. 

Artwork by Jason Winter

Click study card to enlarge

REFERENCES:

1) http://circ.ahajournals.org/content/91/5/1602.full

2) http://medicmadness.com/2010/05/dextrocardia-and-proper-lead-placement/

3) http://europepmc.org/articles/PMC2564044

4) http://www.wikidoc.org/index.php/Dextrocardia_electrocardiogram

5) http://www.emtcity.com/topic/14811-modifying-paddles-placement-dextrocardia/

6) https://www.researchgate.net/publication/8478385

7) http://emj.bmj.com/content/23/2/147.abstract

8) http://ecgguru.com/ecg/dextrocardia

9) https://en.wikipedia.org/wiki/Marden%E2%80%93Walker_syndrome

10) https://en.wikipedia.org/wiki/Primary_ciliary_dyskinesia

Acute coronary syndrome and infarctions

De Winters T waves

***ANTERIOR STEMI EQUIVALENT ALERT***

The aims of this post is really to educate and alert all emergency ambulance staff, emergency department physicians and interventional cardiologists, that are involved in the care of STEMI patients in the recognition of de Winters T waves high-risk ECG pattern. 

I hope to achieve by doing so, more lives and myocardial muscle could be saved in the future. These patient's need to receieve emergent reperfusion therapy with PCI or thrombolysis. 

Please share this post and educate others practitioners about De Winters T waves :) 

Background

• First identified in 2008 by Dr. de Winter found a characteristic patterns in 30 of his 1532 patient database of anterior MI
• 2% of proximal LAD occlusions will have this presentation
• de Winter T-waves is a proposed STEMI-equivalent proposed by the AHA

Diagnostic Features

1. Precordial ST-segment depression at the J-point, 1-3 mm
2. Tall, peaked, symmetric T waves in the precordial leads
3. Lead aVR shows slight ST-segment elevation in most cases

Figure 1: 12-lead ECG showing De Winters T waves, (ECG above and below is courtesy of Dr Steve Smith, check out his excellent blog) @: http://hqmeded-ecg.blogspot.co.uk/

Figure 2: Blue arrows show hyper acute T waves, Red arrows show ST depression

Figure 3: 8 patient's examples of de Winters T waves, all patient's had LAD occlusion.

Figure 4:

Figure 5: Please save this study card and share it with your friends and colleagues, the more emergency medical staff that recognize this high risk pattern, then more lives could be saved  

Differential Diagnosis:

- Peaked T-waves
- MI (hyperacute T waves)
- Hyperkalemia
- Benign Early Repolarization
- De Winter's T waves (acute LAD occlusion)

References and links

* http://hqmeded-ecg.blogspot.co.uk/2009/02/hyperacute-t-waves.html
* http://lifeinthefastlane.com/ecg-library/de-winters-t-waves/

Giant T waves

48 year old male who fell while intoxicated, patient was also complaining of right-sided chest pain on arrival of the emergency services.

PMH:

Past medical history: Polio, Liver carcinoma, Pulmonary hypertension, patient is also alcohol dependent, and he has had numerous attendances at the Emergency Department (ED) regarding alcohol issues and chest pain over the last few months. On this occasion the patient was admitted to a cardiology ward for further investigations because his ECG showed widespread global diffuse T-wave inversion. The patient had a echo the following day after admission, the results showed Right-sided right ventricular enlargement.

Inverted T waves are frequently seen in electrocardiograms (ECGs) and may represent a myriad of pathologies or nonspecific change. However, deep (giant) inverted T waves are only seen in a few clinical conditions. Presence of giant T waves should generally prompt investigations for apical (Yamaguchi) variant of hypertrophic cardiomyopathy, raised intracranial pressure, severe myocardial ischemia, post tachycardia syndrome, and a few other conditions. 

What is Global (Diffuse) T-wave inversion?

• T wave is inverted in most of the standard leads except aVR, which shows a reciprocal upright T wave.

• The QT interval is often prolonged, and T-wave inversion is often symmetric and “giant” >10 mm, i.e, 2 big boxes).

• This is different from Wellens T waves, wherein the T abnormality is limited to the anterior leads (especially V2-V4) and ST segment is slightly upsloping.

Most common causes of Global T-wave inversion

1) Myocardial ischemia

2) Intracranial hemorrhage or any intracranial process

3) Hypertrophic cardiomyopathy

4) High catecholamine states: cocaine use, pheochromocytoma, Takotsubo (stress-induced) cardiomyopathy

5-Other: pericarditis or myocarditis, high-grade AV block, Pulmonary Embolism.

Figure 1: This is the patient's ECG that was recorded two months prior to this hospital admission, what abnormalities do you see?

Figure 2: ECG shows widespread diffused T wave inversion. Giant T wave inversion can be broad and deep or just deep T inversions. A depth of T wave of >10 mm or above is generally considered as deep T inversion 

Figure 3: Illustrated copy of above ECG, shows the pre-hospital ECG recorded by paramedics on scene in the patient own home.

Figure 4: This 12-lead ECG was recorded by the Emergency Department staff on the day of admission.

Figure 5: Shows long rhythm strip recorded 

Figure 6: This study card of giant T-wave inversion is for you to save as a memo aid, save the image to your electronic devices for future reference.

This is a interesting case I have NOT seen that often, if you have any interesting ECG's like this in your collection, that you would like to share with others, then please send them to me at: ECG.EDUCATOR@GMAIL.COM

References and further reading:

1) http://circep.ahajournals.org/content/2/6/e42.full

2) http://aaimedicine.org/journal-of-insurance-medicine/jim/2004/036-02-0153.pdf

3) https://www.researchgate.net/publication/18940327_Giant_T_wave_inversion

4) http://www.ccjm.org/index.php?id=107937&tx_ttnews[tt_news]=368617&cHash=6eff580824667de2a5a83d7c3317ec76

5) http://ecgguru.com/ecg/giant-t-waves

6) http://europepmc.org/articles/PMC490091

7) http://www.consultantlive.com/cardiovascular-diseases/inverted-t-wave-differential-diagnosis-adult-patient

8) http://europepmc.org/articles/PMC2499903

9) http://www.scielo.org.ar/pdf/rac/v77n2/en_v77n2a12.pdf

10) http://www.sciencedirect.com/science/article/pii/073510979090225E

11) https://www.researchgate.net/publication/8410427_Giant_negative_T_waves

12) http://www.mayoclinicproceedings.org/article/S0025-6196(11)61982-4/fulltext

13) http://www.hindawi.com/journals/crivam/2011/942045/

14) http://www.jecgonline.com/article/S0022-0736(09)00377-X/fulltext

15) http://ecg-interpretation.blogspot.co.uk/2013/01/ecg-interpretation-review-59-t-wave.html

16) http://hqmeded-ecg.blogspot.co.uk/2015/04/giant-inverted-t-waves-in-elderly.html

17) http://circep.ahajournals.org/content/2/6/e42.extract

18) http://heart.bmj.com/content/91/7/913.full

19) http://europace.oxfordjournals.org/content/early/2014/08/06/europace.euu190

21) http://circ.ahajournals.org/content/112/20/e322.full

22) http://www.ajronline.org/doi/abs/10.2214/AJR.07.7116

23) http://www.academia.edu/24365787/Giant_T_waves_simulating_apical_hypertrophic_myocardiopathy_that_disappear_with_sodium_nitroprusside_administration

24) https://www.jstage.jst.go.jp/article/internalmedicine/55/5/55_55.5770/_article

25) https://drsvenkatesan.com/tag/giant-t-wave-inversion/

26) http://www.ingentaconnect.com/content/bsc/jce/2002/00000013/00000006/art00023

27) https://ojs.kardiologiapolska.pl/kp/article/viewFile/KP.2013.0330/7577

Basic to Advanced ECG Classes available

My name is Jason Winter and I work for a NHS Ambulance service in the UK as a ambulance clinician. I hold a Diploma in Electrocardiography by the Society of Cardiological Science and Technology (SCST) and also I have attended other specialist ECG courses at university level 6 and 7. My classes can be arranged to suit the need of your students. Please send a email for further details. ECG.Educator@gmail.com

Introduction to the 12-lead ECG

TO BE COMPLETED

Bundle Branch Blocks

In BBB, one or the other (or both) of these bundle branches no longer conduct electrical impulses normally. This can occur from disease or damage to one of the bundle branches, or it may occur for no apparent reason in completely healthy people. When the electrical impulse is delayed in reaching its respective ventricle, the delay shows up as a distinctive pattern on the ECG called a BBB. The chief effect of a BBB is to disrupt the normal, coordinated and simultaneous contraction of the two ventricles. The contraction of one ventricle (the one whose bundle branch is blocked) occurs slightly after the contraction of the other.

People with BBB usually will have either right bundle branch block (RBBB) or left bundle branch block (LBBB), depending on which of the two bundle branches is "blocked." Sometimes both bundle branches are affected, and the BBB pattern on the ECG is not clearly identifiable as either right or left BBB - in this case, the BBB is referred to as an intraventricular conduction delay (IVCD).