Evolution of electrocardiographic abnormalities in association with neuromuscular disorders and survival in left ventricular hypertrabeculation/noncompaction.

BACKGROUND: Left ventricular hypertrabeculation/noncompaction (LVHT) is frequently associated with neuromuscular disorders (NMDs) and electrocardiographic (ECG) abnormalities. The prognostic relevance of newly developed ECG abnormalities in LVHT and its dependency on NMD is largely unknown. Aim of the following retrospective cohort study in LVHT patients was thus to assess the development of new ECG abnormalities and its dependency on NMD and survival.
METHODS: Included were patients in whom (a) LVHT was diagnosed between 1995 and 2011, (b) baseline ECG recordings (bECG), and (c) follow-up ECG recordings (fECG) were available. Survival status was assessed in June 2013.
RESULTS: Included were 105 patients (mean age 55 years, 36 females, 67 with NMD). The interval between bECG and fECG was 3.6 years. ECG abnormalities increased in 46%, were unchanged in 44% and decreased in 11%. Increase was associated with age (59 years vs 49 years, P = 0.0169), exertional dyspnea (79% vs 53%, P = 0.013), heart failure (81% vs 47%, P = 0.0149), a left ventricular end-diastolic diameter >57 mm (76% vs 43%, P = 0.004) and a left ventricular fractional shortening <25% (68% vs 42%, P = 0.0429). New ECG abnormalities were ST-T wave abnormalities (n = 35), left anterior hemiblock (n = 6) and Q waves (n = 6). During 71 months, 40 patients died. Multivariate analysis identified age, male gender, "constant" (in bECG as well as fECG) atrial fibrillation, disappearance of atrial fibrillation, development as well as disappearance of low voltage ECG, increase of QRS width, constant QRS width >120 ms and constant tall QRS complexes as predictors for mortality.
CONCLUSIONS: LVHT-patients develop frequently new ECG abnormalities of prognostic relevance.