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.

Noncompaction in mitochondrial myopathy: visible on microscopy but absent on macroscopic inspection.

OBJECTIVES: Disappearance of left ventricular hypertrabeculation (LVHT) over time has been occasionally recognized, but absence on echocardiography and autopsy and presence on histological examination after autopsy has not been reported. METHODS: Routine investigations such as chocardiography, cardiac MRI and coronary angiography were applied. Autopsy studies included macroscopic inspection and dissection but also histological work-up. RESULTS: In a 64-year-old male, LVHT was diagnosed at age 51 years during diagnostic work-up for hypertrophic cardiomyopathy. He had a history of mitochondrial myopathy which was diagnosed long before the cardiac problem became evident. Thickening of the left ventricular myocardium increased over years, resulting also in thickening of the trabeculations and the disappearance of the intertrabecular recesses. This is why LVHT was no longer visible on echocardiography shortly before death at age 64 years. The autopsy revealed that macroscopically no LVHT was visible but upon histological work-up the preformed recesses were still visible but had become unfolded. CONCLUSIONS: This case shows that LVHT may disappear due to thickening of the trabeculations but may remain visible on postmortem histological examination in patients with hypertrophic cardiomyopathy from a mitochondrial myopathy.

Quantitative electrocardiographic measures, 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. Quantitative ECG-measures (QEMs) are risk markers for mortality in cardiomyopathies. We measured QEMs in the ECGs in LVHT patients with and without NMDs. METHODS: Included were patients in whom (a) LVHT was diagnosed between 1995 and 2011 and (b) baseline ECG recordings were available. All underwent a clinical examination and were invited for a neurological investigation. QRS duration, QT, QTc and PR intervals were analyzed. Survival status was assessed in June 2011. RESULTS: In 141 patients (mean age 54 years, 49 females) QRS duration ranged from 40 to 200 ms, a QRS duration >120 ms was found in 19% and was associated with increased age, heart failure, left ventricular dilatation and systolic dysfunction (P < 0.001). QT intervals ranged from 240 to 600 ms. The QTc intervals ranged from 302 to 612 ms, a QTc interval >440 ms was found in 38% and was associated with left ventricular dilatation and systolic dysfunction (P < 0.001). PR intervals ranged from 90 to 360 ms, a PR interval >200 ms was found in 16% and associated with left ventricular dilatation (P < 0.01). No QEM differences were found in 86 patients with and 13 without NMD. During 59 months follow-up 45 patients died. QEMs were no mortality predictors, whereas multivariate analysis identified heart failure (P < 0.01), atrial fibrillation (P < 0.01) and diabetes mellitus (P < 0.05) as mortality predictors. CONCLUSIONS: Prolonged QRS complexes, PR and QTc intervals in LVHT are associated with heart failure and left ventricular dilatation, but not with NMD. The prognostic role of QEMs in LVHT needs further investigations in larger series.

Pathomorphologic findings in left ventricular hypertrabeculation/noncompaction of adults in relation to neuromuscular disorders.

BACKGROUND: Aim of this study was to assess pathomorphologic findings (PATHO) in patients with echocardiographically (ECHO) diagnosed left ventricular hypertrabeculation/noncompaction. METHODS: ECHO-criteria for LVHT were: >3 trabeculations, moving synchronously with the compacted myocardium, and forming the noncompacted part of a two-layered myocardium. At autopsy, the hearts were investigated according to the pathologists' preferences. RESULTS: Twelve patients (2 females, age 27-81 years) were included. Seven suffered from neuromuscular disorders, 5 patients were not investigated neurologically. The specimens were acquired after explantation during heart transplantation (n=1), death due to heart failure (n=6), sudden death (n=2), pneumonia (n=2) and stroke (n=1). Eight hearts were investigated without fixation and 4 after formaldehyde fixation. The hearts were opened along the long-axis, in 3 hearts additional short-axis cuts were carried out. At PATHO the trabecular meshwork was better visible in the formaldehyde-fixed hearts than in the fresh hearts. Differentiation from papillary muscles was easier on the long-axis cuts, whereas the two-layered structure was better visible on short-axis cuts. The trabecular pattern was similar in patients with neuromuscular disorders and those who did not undergo neurologic investigation. Subendocardial fibrosis was found in each case. Due to the complex three-dimensional geometry, it was impossible to count the number of trabeculations. CONCLUSION: Formaldehyde-fixation should be performed when comparing ECHO with PATHO findings in LVHT. Long-axis as well as short-axis cuts should be carried out in order to assess the course of trabeculations and the extent of the two-layered structure. Subendocardial fibrosis in LVHT deserves further research.