PMC9869367_01
Changes in ECG during treatment. (A) Holter on admission showed R on T phenomenon (red arrow) and torsades de pointes. (B) After treatment of propranolol and magnesium sulfate, the QT interval was in the normal range, and no obvious ventricular premature beats were found. (C) Recurrence of torsades de pointes episode during oral propranolol.
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F1
Tdp (Figure 1A). The QTc ranged from 410 to 468 ms. An ECG showed that the premature ventricular contractions were significantly reduced and that no ventricular tachycardia (VT) occurred, and the QTc was 416 ms (Figure 1B). Tdp (Figure 1C). Temporary subclavian pacing was given to the patient, and vasoactive drugs were used to maintain circulatory stability.
(A,B) the patient and her mother had a heterozygous mutation of AKAP9 gene mutation of c.11714T > C (p.M3905T). (C) Her father had no relevant genetic mutations.
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F2
As a result, a heterozygous mutation, namely, c.11714T > C (p.M3905T), in the AKAP9 gene of the patient was detected, which was inherited from her mother (Figure 2), whose ECG was normal without QT prolongation and no history of syncope.
Chest x-ray after the implantation of the implantable cardioverter-defibrillator.
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F3
Considering that the child had syncope after drug treatment, she was implanted with an implantable cardioverter defibrillator (ICD) under general anesthesia after 7 days of stabilization (Figure 3).