Author + information
- Claudia Stöllberger, MD∗ ( and )
- Josef Finsterer, MD, PhD
- ↵∗Krankenanstalt Rudolfstiftung, Steingasse 31/18, A-1030 Vienna, Austria.
With interest we read the article by Stacey et al. (1) about systolic and diastolic criteria for left ventricular hypertrabeculation/noncompaction (LVHT). Uniform diagnostic criteria for LVHT are a still unsolved problem in echocardiography as well as other imaging modalities like cardiac magnetic resonance (CMR). Whether the results of their investigations will lead to more clarification is questionable due to the following reasons: 1) No pathoanatomic gold standard is provided; thus, neither sensitivity nor specificity of the proposed criteria can be assessed. 2) It remains uncertain in how many patients LVHT was diagnosed by echocardiography. There is a need to calculate the percentage of LVHT patients in whom LVHT was diagnosed on echocardiography and CMR, on CMR but not on echocardiography and on echocardiography but not on CMR. 3) The duration and quality of follow-up remain uncertain. Were follow-up data obtained for each of the included patients? 4) Differentiation between LVHT on the one hand and papillary muscles, false tendons, and aberrant bands on the other is a difficult issue because these structures are seen frequently, and there is considerable anatomic variability (2,3). To our knowledge, the proposed “papillary muscle classification system” is not based on any pathoanatomic classification. Furthermore, it seems rather difficult to differentiate between papillary muscles and trabeculations when only short-axis views are considered. Only by using longitudinal views will it be possible to visualize the communication of the papillary muscles with the mitral valve leaflets via the chordae tendineae. Not to differentiate between LVHT and papillary muscles is not acceptable because LVHT diagnostic criteria definitions clearly exclude papillary muscles from the evaluation. 5) There is no need to distinguish between “myopathic LVHT” and “normal variants” because they are morphologically the same and have a similar complication rate and outcome. Normal variants may have subclinical myopathy or may have chromosomal abnormalities, which manifest only in the heart. This is why we recommend referring all LVHT patients to a myologist to also detect neurological abnormalities which are clinically inapparent for the cardiologist. As an initial step, the authors should provide information about how many of their patients had an elevated creatine kinase level and in how many patients was LVHT familial. Familial LVHT may suggest hereditary disease, including neuromuscular disorders.
Additionally, we have the following questions regarding the presented data. 1) It was previously reported that echocardiographically diagnosed LVHT is more often visible on CMR in patients with an enlarged left ventricle and systolic dysfunction than in those with normal-size, well-contracting left ventricles (4). Did any of the patients undergo follow-up CMR studies and did the ratios of noncompacted to compacted layers and the trabecular mass change? 2) From pathoanatomic investigation we know that endocardial fibrosis is frequently found in LVHT patients (5). Was that phenomenon also visible on CMR? 3) Because of unknown reasons, LVHT was diagnosed more frequently in male than female patients. How can the relatively high proportion of female patients in the present study be explained?
In conclusion, only close cooperation between cardiologists, radiologists, neurologists, and cardiac pathologists will solve the enigmas of LVHT.
- American College of Cardiology Foundation