Case Study: A 28 years old female presented in the OP with complains of palpitations and giddiness. There was a positive history of anxiety, chest pain and episodes of fainting. The presentation was ideal for holter monitoring to narrow down the diagnosis. She was prescribed a 5 day smart heart holter monitoring program. The holter report demonstrated the occurrence of Short PR Interval (< 120ms) with Prolonged QRS Complexes (>110ms). The instances of premature ventricular complexes and supra ventricular complexes were shown with magnitude and time of occurrence on those 5 days. The AI engine of the Vigo platform analysed the report and suggest the presence of WPW syndrome by reading the short PR interval and prolonged QRS complexes. Furthermore, the appearance of premature ventricular complexes were suggested as benign. The patient was treated conservatively. The clear and precise smart heart ECG report avoided the need for surgical intervention in the patient. The follow up ECGs showed fewer instances of tachycardias.
Wolff-Parkinson-White is characterized by presence of congenital “accessory pathway” . This pathway connects the electrical system of atria and ventricle directly by bypassing atrioventriclar node. This phenomenon thus produces episodes of tachyarrthmias. It was first described in 1930 by Luis Wolf, John Parkinson and Paul Dudley White. The syndrome shows the incidence of 0.1-0.3 per 1000 and is associated with risk of sudden cardiac death.
Understanding the occurrences of tachyarrthmias
In a normal heart sinus node is the gatekeeper to create necessary action potential to maintain appropriate heart pressure for normal body circulation. In cases of WPW, an electric pathway bypasses the sinus code and reaches the ventricle earlier. This detour activates the ventricle too early and is known as “preexcitation”. The extra pathway can also transmit electrical impulses from the ventricles back to the atria, disrupting the coordinated movement of the electrical signals through the heart, leading to changes in the heart rhythm.
ECG changes and findings
Electrophysiology of ECG changes
The typical ECG finding of WPW is a short PR interval and a “delta wave.“ A delta wave is slurring of the upstroke of the QRS complex. This occurs because the action potential from the sinoatrial node is able to conduct to the ventricles very quickly through the accessory pathway, and thus the QRS occurs immediately after the P wave, making the delta wave. Clinical features
- Younger age
- A rapid, fluttering or pounding heartbeat (palpitations)
- Dizziness or lightheadedness
- Shortness of breath
- Chest pain
- Difficulty breathing
Why do we need to diagnose and manage the condition proactively?
Stand alone WPW syndrome doesn’t cause serious problems. However, in cases of any other cardiac conditions, the combination becomes fatal. Atrial fibrillation is seen in 20% and Atrial flutter in 7% of WPW syndrome. Due to erratic action potentials, patient with WPM and AF have higher ventricular rates than those without WPW, may result in degeneration to VT or VF.
Gold standard is holtermonitoring .The device records your heart’s activity while you perform your everyday activities for days as prescribed by the treating physician.
1.1. https://www.mayoclinic.org/diseases-conditions/wolff-parkinson-white-syndrome/symptoms-causes/syc-20354626 accessed on 03.04.21
2. https://www.healio.com/cardiology/learn-the-heart/ecg-review/ecg-topic-reviews-and-criteria/wpw-reviewaccessed on 03.04.21
3. https://litfl.com/pre-excitation-syndromes-ecg-library/ accessed on 03.04.21 4.https://emedicine.medscape.com/article/159222accessed on 03.04.21 5.https://jamanetwork.com/journals/jama/article-abstract/345030accessed on 03.04.21