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Long QT syndrome with a de novo CALM2 mutation in a 4‐year‐old boy
Author(s) -
Fujita Shuhei,
Nakagawa Ryo,
Futatani Takeshi,
Igarashi Noboru,
Fuchigami Takamasa,
Saito Shinsuke,
Ohno Seiko,
Horie Minoru,
Hatasaki Kiyoshi
Publication year - 2019
Publication title -
pediatrics international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.49
H-Index - 63
eISSN - 1442-200X
pISSN - 1328-8067
DOI - 10.1111/ped.13959
Subject(s) - medicine , catecholaminergic polymorphic ventricular tachycardia , ventricular fibrillation , cardiology , long qt syndrome , qt interval , sinus tachycardia , short qt syndrome , sinus rhythm , ventricular tachycardia , cardiopulmonary resuscitation , electrocardiography , anesthesia , resuscitation , atrial fibrillation , ryanodine receptor 2 , ryanodine receptor , calcium
Background Human calmodulin (CALM) gene mutation has been reported to be related to inherited arrhythmia syndromes, but the genotype–phenotype relationship remains unclear. Methods and Results We report here a 4‐year‐old boy who had cardiac arrest while playing in a kindergarten playground. Cardiopulmonary resuscitation was initiated immediately. Eleven minutes after the cardiac arrest, ambulance crews arrived and an automated external defibrillator was attached. His heart rhythm, which was ventricular fibrillation (VF), was returned to sinus rhythm after only one shock delivery. The boy was brought to hospital by air ambulance. During transfer, electrocardiogram (ECG) showed transient VF. On arrival, chest radiograph showed a cardiothoracic ratio of 55% without pulmonary congestion. A 12‐lead ECG showed a normal sinus rhythm, biphasic T wave, and prolongation of the corrected QT interval. On ECG, VF was preceded by torsade de pointes or frequent polymorphic premature ventricular contractions (PVC). Echocardiography showed a normal heart structure with decreased cardiac function. On the second day of hospitalization, ECG showed remarkable QT prolongation, T‐wave alternans, and frequent PVC. Thereafter, propranolol was started. The ECG showed rapid improvement of QT prolongation and T‐wave abnormality. Genetic test indicated a CALM2 mutation, and he was diagnosed with long QT syndrome‐15 (LQT15). Conclusions CALM mutations cause long QT syndrome (LQTS), catecholaminergic polymorphic ventricular tachycardia (CPVT) and idiopathic VF. This patient with a CALM2 p.N98S mutation had both phenotypes of LQTS and CPVT.