This is the ECG of a 19 years old male who presented to ED with recurrent episodes of palpitations.
No chest pain or breathlessness at any point in time.
No old ECGs for comparison.
Currently completely asymptomatic.
This is the ECG of the patient when asymptomatic in between the episodes.
Then the patient suddenly developed another episode of palpitations, so another ECG was done, this is what you found.
Courtesy to Dr. Chris Beng, Emergency Medicine Consultant, UK.
What is your diagnosis of the underlying condition?
Let's analyze the presentation first:
This is an excellent case to cover one of the most important D.D. in Emergency Cardiology, which is the D.D. of syncope/pre-syncope/palpitations from the ECG perspective.
When you interpret an ECG of a syncope/pre-syncope/palpitations patient, & before you call it normal, you must first rule out:
1) ACS.
2) Arrhythmias, heart blocks.
3) Pulmonary Embolism.
4) 2 Abnormal intervals:
- Long / Short PR interval.
- Long / Short QT interval.
5) 3 Genetic problems:
- Hypertrophic Cardiomyopathy (HCM).
- Brugada Syndrome.
- Arrhythmogenic Right Ventricular Dysplasia (ARVD)
Now, Let's analyze the ECG:
If you look carefully at the above ECG (with no VT), you will notice the presence of the following abnormalities:
T wave inversion in V1-V3.
Epsilon wave in V2 (a funny wave at the end of the complex & beginning of the ST segment).
When you look at the VT ECG, you will notice that it has a LBBB morphology.
If you combine all of the above, you will easily find the underlying diagnosis.
The Answer:
This was a case of Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC).
Also known as Arrhythmogenic Right Ventricular Dysplasia (ARVD).
Discussion:
It is the second most common cause of sudden cardiac death in young people (after HOCM), causing up to 20% of sudden cardiac deaths in patients < 35 years of age.
Typically inherited as an autosomal dominant (AD) disease, more common in men than women (3:1), and in people of Italian or Greek descent.
Estimated to affect approximately 1 in 5,000 people overall. (not as uncommon as you might think).
Pathogenesis:
Characterized pathologically by fibro-fatty replacement of the right ventricular myocardium, resulting in paroxysmal ventricular arrhythmias and sudden cardiac death.
ECG findings:
ARVD is associated with characteristic ECG abnormalities:
Epsilon wave (most specific finding, seen in 30% of patients).
T wave inversions in V1-3 (85% of patients).
Prolonged S-wave upstroke in V1-3 (95% of patients).
Localized QRS widening in V1-3.
Paroxysmal episodes of ventricular tachycardia with LBBB morphology (e.g. right ventricular VT).
When ARVC patients develop Ventricular Tachycardia (VT), it has LBBB morphology.
Let's talk about some basics first to be able to understand the above statement.
FACT number 1: With any LBBB, the right ventricle is stimulated first (as the left bundle is blocked), & this results in this shape in V1.
FACT number 2: With any RBBB, the left ventricle is stimulated first (as the right bundle is blocked), & this results in this shape in V1.
There are many applications to these 2 simple facts:
1) Any PVC with RBBB morphology is coming from the left ventricle (the left ventricle is stimulated 1st, just like RBBB) & vice versa.
2) With pre-excitation syndrome, if the accessory pathway is in the left side, the ECG will be with RBBB morphology (& vice versa).
3) If the focus of the VT is coming from the right ventricle, the complexes with take the shape of LBBB as the right ventricle is stimulated first (& vice versa).
This is an example of a VT coming from the left ventricle (left ventricle is stimulated 1st = same as RBBB = RBBB morphology)
ARVC is a good example of a VT that comes from the right ventricle, this is where the pathology is, i.e. (right ventricle is stimulated 1st = same as LBBB = LBBB morphology).
This particular patient was known to have ARVC & all his VTs self self-terminated which made our life much easier.
Fontaine leads
Fontaine bipolar precordial leads (F-ECG) are used to increase the sensitivity of epsilon wave detection. Leads are placed as shown:
Right Arm (RA) over the manubrium.
Left Arm (LA) over the xiphoid process.
and Left Leg (LL) in the standard V4 position (5th ICS MCL).
Investigations:
Echo: dilated, hypokinetic right ventricle.
Cardiovascular MRI: investigation of choice, fibrofatty infiltration and thinning of the RV myocardium.
Treatment:
Anti-arrhythmic drugs: beta-blockers (Sotalol) or amiodarone.
Anticoagulants: to prevent thrombus formation due to RV hypokinesis.
Radiofrequency ablation of conduction pathways may be attempted.
Implantable cardioverter-defibrillator (ICD).
In severe cases, cardiac transplantation may be required.
Here is a link to the video that discusses the case above
For references & further readings about ARVC:
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