|LETTER TO THE EDITOR
|Year : 2022 | Volume
| Issue : 1 | Page : 68-69
Macro T-Wave alternans in recurrent orthodromic atrioventricular reentrant tachycardia
Debasish Das, Tutan Das, Subhas Pramanik
Department of Cardiology, All India Institute of Medical Sciences, Bhubaneswar, Odisha, India
|Date of Submission||27-Jul-2021|
|Date of Decision||25-Nov-2021|
|Date of Acceptance||08-Feb-2022|
|Date of Web Publication||26-Apr-2022|
Department of Cardiology, All India Institute of Medical Sciences, Bhubaneswar - 751 019, Odisha
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Das D, Das T, Pramanik S. Macro T-Wave alternans in recurrent orthodromic atrioventricular reentrant tachycardia. J Pract Cardiovasc Sci 2022;8:68-9
|How to cite this URL:|
Das D, Das T, Pramanik S. Macro T-Wave alternans in recurrent orthodromic atrioventricular reentrant tachycardia. J Pract Cardiovasc Sci [serial online] 2022 [cited 2022 Aug 17];8:68-9. Available from: https://www.j-pcs.org/text.asp?2022/8/1/68/344131
A 35-year-old female with structurally normal heart and good biventricular function with history of frequent palpitation for the past 6 months without any history of antiarrhythmic drug consumption in the past, presented in the emergency department with incessant long RP tachycardia in the surface electrocardiogram (ECG) [Figure 1]. Interestingly, the T-wave morphology and amplitude were changing with each alternate beat suggestive of macro T-wave alternans (TWA). Careful observation of the presenting ECG [Figure 1] and ECG during electrophysiology (EP) study [Figure 2] revealed the presence of QRS alternans and RR alternans along with macro TWA depicting a phenomenon of secondary TWA in long RP tachycardia. Serum electrolytes (Na+, K+, Ca++, and Mg++) were within normal limits excluding dyselectronemia (hypocalcemia and hypomagnesemia)-induced TWA. EP study confirmed the presence of RR alternans [Figure 3] with constant VA interval with the same atrial activation pattern during tachycardia. Tachycardia was confirmed to be orthodromic atrioventricular reentrant tachycardia (AVRT) through the right posteroseptal pathway which was successfully ablated. It was not slow-conducting posteroseptal pathway of permanent junctional reciprocating tachycardia. Our case is the first literature illustration of macro TWA in a case of orthodromic AVRT.
|Figure 1: Electrocardiogram showing long RP supraventricular tachycardia with T-wave alternans|
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|Figure 2: During electrophysiological study, narrow complex regular tachycardia showing T-wave alternans, QRS alternans, and RR alternans|
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|Figure 3: Corresponding electrograms showing RR alternans (RR cycle length of 316 and 308 ms), same VA interval, and atrial activation pattern which suggests that there is no beat-to-beat variation of RP interval and P-wave morphology; thus, confirming it as T-wave alternans|
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| Discussion|| |
Macro TWA is a rare electrical phenomenon. It is of two types, primary TWA which is arrhythmogenic and pseudo or secondary TWA which has no arrhythmogenic potential. Primary TWA suggests inhomogeneity in refractoriness of the myocardium which causes unidirectional functional block and reentry resulting in malignant ventricular arrhythmias. Primary TWA is due to beat-to-beat variation in intracellular calcium cycling known as “calcium hypothesis” which gives rise to early after depolarization causing arrhythmia. It is commonly seen in QT prolongation, electrolyte imbalance, acute myocardial ischemia, and in patients with severe left ventricular systolic dysfunction. Secondary or pseudo electrical alternans occurs as a consequence to RR alternans where cardiac movement and respiration also play a role. QRS alternans in orthodromic AVRT is a well-known entity but TWA, as described in our case, is a rare one to be reported. Interestingly, our patient had secondary TWA with associated QRS alternans and RR alternans. Tomcsayni J et al. have reported a case of atrial tachycardia with TWA which disappeared after the termination of tachycardia. TWA has been noted in atrioventricular nodal reentrant tachycardia (AVNRT) also due to group beating. Our case is unique and the first to demonstrate secondary TWA in surface ECG in a case of orthodromic AVRT. The change in LV geometry due to differential filling of the ventricle could be one of the explanations for the secondary TWA. TWA is not unique to AVRT and it does not help to differentiate three supraventricular tachycardias.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Institutional Ethical Committee (IEC) clearance has been obtained.
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Conflicts of interest
There are no conflicts of interest.
| References|| |
Narayan SM. T-wave alternans and the susceptibility to ventricular arrhythmias. J Am Coll Cardiol 2006;47:269-81.
Tomcsányi J, Arányi P. T-wave alternans and atrial tachycardia. Orv Hetil 2020;161:275-7.
Sorgente A, Bernier M, Benito B, Josephson ME. Group beating related T-wave alternans in a patient with atrio-ventricular nodal reentrant tachycardia. Europace 2011;13:1339.
[Figure 1], [Figure 2], [Figure 3]