Consider neuromuscular disorders in association with noncompaction.

To the Editor: With interest, we read the article by Fox et al (1) on a 29-year-old African-American female in whom left ventricular hypertrabeculation (LVHT), also known as noncompaction, was detected upon investigation for heart failure from dilative cardiomyopathy. The presentation raises the following concerns:

LVHT is presented as an exclusively congenital abnormality. In rare cases, however, LVHT can develop during one's lifespan, as confirmed by previous echocardiograms without LVHT. (2) All of these patients suffered from a neuromuscular disorder (NMD). In these patients, LVHT may represent the attempt to compensate for the failing myocardium. (2) No systematic studies have been carried out to investigate the general prevalence of acquired LVHT.

LVHT involving the septum is rare. Among 100 LVHT patients of our own study, septal involvement was found in none of them. How can septal involvement be explained in the presented patient? Did the patient respond to pharmacotherapy? Did the left ventricle decrease in size or did the ejection-fraction increase? It appears premature to implant an cardioverter defibrillator (ICD) and to refer him for heart transplantation without waiting for the response to drug-therapy. Did the patient have a left ventricular bundle branch block and was a biventricular pacemaker considered? Did he have a history of syncope or severe rhythm abnormalities? Which was the indication for oral anticoagulation (OAC)? Were OAC given for severely reduced systolic function, for atrial fibrillation, or for LVHT? Did the patient have a history of previous thromboembolism? In a study on 62 patients with sex, age, and systolic function matched, we did not find an increased risk for thromboembolism. (3) Nonindicated OAC may jeopardize LVHT patients and may be more harmful than beneficial.

LVHT is associated with NMDs in up to 80% of the cases. Obviously, the presented patient was not seen by a neurologist. Was there any indication for a NMD, such as Barth-syndrome, myoad-enylate-deaminase deficiency, myotonic dystrophy, dystrophinopathy, zaspopathy, hereditary neuropathy, Friedreich ataxia, Pompe's disease, a mitochondrial disorder, or laminopathy, which have been reported to be associated with LVHT?

LVHT may not only be diagnosed according to Oechslin's criteria, but also according to Stollberger's or Chin's criteria. (4) Did the patient also fulfill these definitions? According to Oechslin's criteria, the ratio of noncompacted to compacted layer needs to be measured in end-systole. (5) Was the ratio measured in endsystole or end-diastole?

Overall, LVHT patients require thorough and comprehensive investigations, not only by a cardiologist but also by a neurologist. LVHT per se is no indication for an ICD or OAC.

Josef Finsterer, MD, PhD

Krankenanstalt Rudolfstiftung

Vienna, Austria

Claudia Stollberger, MD

Second Medical Department

Krankenanstalt Rudolfstiftung

Vienna, Austria

References

1. Fox EH, Wood ML, Trotter J, et al. New onset heart failure in a 29-year-old: A case report of isolated left ventricular noncompaction. South Med J 2006;99:1130-1133.

2. Finsterer J, Stollberger C, Schubert B. Acquired left ventricular hypertrabeculation/noncompaction in mitochondriopathy. Cardiology 2004;102:228-230.

3. Stollberger C, Finsterer J. Left ventricular hypertrabeculation/noncompaction and stroke or embolism. Cardiology 2005;103:68-72.

4. Stollberger C, Finsterer J. Left ventricular hypertrabeculation/noncompaction. J Am Soc Echocardiogr 2004;17:91-100.

5. Oechslin EN, Attenhofer Jost CH, Rojas JR, et al. Long-term follow-up of 34 adults with isolated left ventricular noncompaction: a distinct cardiomyopathy with poor prognosis. J Am Coll Cardiol 2000;36:493-500.