Isolated left bundle branch block progressing to complete heart block and asystole: A novel presentation of a desmin mutation

Desmin‐related myopathy characterized by non‐compaction cardiomyopathy, cardiac conduction defect, and coronary artery dissection

“…Even though most patients with DES mutations present a combined skeletal and cardiac myopathy, the clinical phenotypes associated with DES mutations are heterogeneous. Among the previously reported DES mutations, R454W, which was found in the case, exhibited a severer clinical course than other DES mutations . It is reported that this type of mutation was associated with an accelerated and severe cardiac phenotype with a high incidence of ventricular arrhythmia, progressive cardiomyopathy, and sudden death .…”

“…Among the previously reported DES mutations, R454W, which was found in the case, exhibited a severer clinical course than other DES mutations . It is reported that this type of mutation was associated with an accelerated and severe cardiac phenotype with a high incidence of ventricular arrhythmia, progressive cardiomyopathy, and sudden death . Therefore, R454W mutation is a ‘red flag’ for clinicians .…”

Isolated left bundle branch block in the young: case reports and review of literature

“…An 11‐year‐old Caucasian girl with de novo desminopathy [R454W mutation in Desmin ( DES ) gene] has also been reported with an isolated LBBB aberrancy which rapidly progressed to complete AV block. A cardiac MRI was not obtained; however, no structural cardiac abnormalities were noted on echocardiography 5 . Agarwal et al.…”

“…It was identified in only one child in two large pediatric series in which electrocardiograms of >550,000 healthy children were evaluated 3,4 . Two additional patients have been reported, one of whom carried a mutation in the Desmin gene 5,6 . A recent report described five children (0.5 to 5.7 years old) with varying degrees of ventricular dysfunction and isolated LBBB aberrancy who showed an improvement in left ventricular function after epicardial left ventricular lead placement and dual‐chamber pacing 7 .…”

DES mutation associated with cardiac hypertrophy and alternating bundle branch block

“… 3 , 4 According to a meta-analysis enrolling 159 DES mutation carriers with 40 different mutations, 5 74% of carriers presented neurological signs and cardiologic signs; 70% of carriers had myopathy and one-third of them had normal serum creatine kinase level; 50% of carriers had cardiomyopathy; and 60% had cardiac conduction disease or arrhythmia, among which atrioventricular block (AVB) was quite common. Isolated left bundle branch block progressing to complete heart block and asystole has been found in pediatric patients with DES mutation, 6 but alternating bundle branch block (ABBB) remained scarcely reported.…”