Discussion:
This is the first case reporting the association of Lamin A/C with
ventricular noncompaction and a vertical vein connection from the LSPV
to the SVC. The occurrence of atrial and ventricular arrhythmias and AV
block has been typically observed (3-5). Interestingly in these 2
sisters the atrial arrhythmias arose from the basal interatrial septum,
closed to the area where the AV block was present. In addition
significant interatrial conduction delay was present. Hence the MRI in
one patient did not show any late enhancement nor scar. The disease is
inherited as autosomal dominant trait with high penetrance; most
importantly it may be associated with an adverse cardiac outcome
including heart transplantation and malignant ventricular arrhythmia (5,
6). It is important for the electrophysiologist to diagnose Lamin A/C
mutations, as the prognosis is worse and therefore ICD implantation
recommended in many cases(7).
Irregular atrial flutters with intraatrial conduction delay are
impossible to map with contact mapping systems using summation of serial
activation measurements annotated to a reference, because atrial
conduction times are not constant. Instead beat to beat analysis of the
simultaneous activation in the entire heart chamber shows the origin of
arrhythmias at the instant without annotation. Noncontact mapping of the
electrical potential has limitations set by the physics of the
electrical field (1). But the development of a novel mapping system
analyzing the source of the electrical field (charge density and dipole
density) has allowed successful treatment of these 2 patients without
major arrhythmias over a follow up of 1.5 and 3 years, as demonstrated
in PM and ICD interrogation.
Key Teaching Point :
We describe several cardiac disorders associated with Lamin A mutation
in the same family including, dilated cardiomyopathy, left ventricular
non compaction, complex atrial and ventricular arrhythmias and a
vertical vein connection.
Ablation of complex atrial arrhythmias was possible by the use of
noncontact dipole density mapping and radiofrequency ablation