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Quiz Time
Electrocardiography Quiz Parag Barwad Department of Cardiology, PGIMER, Chandigarh, India
ECG Quiz Question - analyze the ECG Figure 1.
Clinical Details A 32‑year‑old male patient had an episode of palpitation
lasting for 3 h. The onset was abrupt, but there was no hemodynamic compromise. There is a history of similar episodes since last 2 years, lasting for few hours with spontaneous termination. However, required intravenous verapamil for termination on few occasion. The echocardiogram done was normal.
Figure 1: Electrocardiography for quiz.
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Website: www.j-pcs.org
DOI: 10.4103/2395-5414.157578
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Address for correspondence: Dr. Parag Brawad, Department of Cardiology, PGIMER, Chandigarh ‑ 160 012, India. E‑Mail:
[email protected]
Journal of the Practice of Cardiovascular Sciences ¦ January-April 2015 ¦ Volume 1 ¦ Issue 1
[Downloaded free from http://www.j-pcs.org on Wednesday, September 28, 2016, IP: 158.181.64.173] Brawad: Quiz time
Figure 2: Electrocardiography quiz answer.
Electrocardiography features
• R egular tachycardia with right bundle branch block (RBBB) morphology, QRS duration of 120 ms • Left axis deviation • Inverted P waves are seen, best in lead III (red arrow) • Constant QRS and P relationship (red arrow).
Interpretation [Figure 2]
• B road, complex regular tachycardia in young patients is usually supraventricular tachycardia with aberrancy • However, any broad complex tachycardia not fulfilling the criteria for a typical bundle branch block (RBBB or left bundle branch block), may be a tachycardia of ventricular origin • RBBB usually has an associated right axis deviation • Thus, the present patient has a ventricular tachycardia (VT) arising from the left posterior fascicle (fascicular VT) • Though atrioventricular dissociation is a diagnostic feature for VT, this is seen in only 50% of patients. In fact, up to 25% of patients in VT may have 1:1 ventriculoatrial conduction, as shown, in this case. Further case details: The patient was taken‑up for electrophysiological study, which showed recurrently
inducible left posterior fascicular VT, for which a successful radiofrequency ablation was performed.
Comments
• F ascicular VT is a relatively benign variety of VT arising from the left ventricle with re‑entry within the posterior left fascicle as the possible mechanism • Electrocardiography characteristics of fascicular VT are RBBB with left axis deviation/northwest axis, with relatively narrow QRS • This tachycardia usually does not cause hemodynamic compromise and occur in younger population • However, in few patients incessant tachycardia may cause left ventricular dysfunction • Verapamil/Diltiazem is effective in terminating this VT; Adenosine is ineffective • Radiofrequency ablation has a success rate of 90% • Early recognition and differentiating it from other VTs is important in view of its treatment strategy. How to cite this article: Barwad P. Electrocardiography quiz. J Pract Cardiovasc Sci 2015;1:72-3. Source of Support: Nil. Conflict of Interest: None declared.
Journal of the Practice of Cardiovascular Sciences ¦ January-April 2015 ¦ Volume 1 ¦ Issue 1
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