|LETTER TO EDITOR
|Year : 2021 | Volume
| Issue : 3 | Page : 187-188
Echocardiography-guided arrhythmic risk prediction in the long qt syndrome
Rakesh Agarwal1, Anunay Gupta2
1 Department of Cardiology, Institute of Postgraduate Medical Education and Research, Kolkata, West Bengal, India
2 Department of Cardiology, Vardhman Mahavir Medical College and Safdarjung Hospital, New Delhi, India
|Date of Submission||06-Mar-2021|
|Date of Decision||06-Mar-2021|
|Date of Acceptance||06-Apr-2021|
|Date of Web Publication||26-Oct-2021|
Department of Cardiology, SSKM Hospital and Institute of Postgraduate Medical Education and Research, AJC Bose Road, Kolkata - 700 020, West Bengal
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Agarwal R, Gupta A. Echocardiography-guided arrhythmic risk prediction in the long qt syndrome. J Cardiovasc Echography 2021;31:187-8
A 31-year old man presented to the cardiology emergency department with palpitations. An electrocardiogram (ECG) obtained showed polymorphic ventricular tachycardia [Figure 1]a. The patient developed cardiac arrest in the ER and was resuscitated with synchronized direct current cardioversion. A baseline ECG showed prolonged QT (corrected QTc 641 msec by Bazett's formula) [Figure 1]b.
|Figure 1: (a) ECG showing VT; (b) Baseline ECG showing Long QT; (c) Electromechanical Window on Echocardiography|
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Echocardiography revealed no structural abnormality. However, the electromechanical window (EMW) was found to be negative with a value of − 49 ms [Figure 1]c. Coronary angiography and cardiac magnetic resonance imaging were normal. An implantable cardioverter-defibrillator was implanted and the patient was discharged for routine follow-up.
The electromechanical window refers to the difference between mechanical and electrical systole in the same heart beat. Normally, mechanical systole is longer than electrical systole, resulting in the EMW being a positive number. In patients with long QT syndrome (LQTS), the EMW is negative as the electrical systole becomes prolonged.
Mechanical systole is calculated from beginning of QRS to aortic valve closure. Electrical systole is calculated as the QT interval from the ECG for the same beat. EMW has been shown to outperform QTc in predicting symptomatic patients. Furthermore, the measurement has shown good reliability among different operators. Exercise-induced greater negativity of the EMW and drug response as judged by reduced negative values (i.e., more positive values) may provide assessment of arrhythmic risk in patients with LQTS.,
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.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
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