Author + information
- Claudia Stöllberger, MD⁎ ( and )
- Josef Finsterer, MD
- ↵⁎KA Rudolfstiftung, 2nd Medical Department, Juchgasse 25, Vienna A-1030, Austria
With interest we read the report by Petersen et al. (1) concerning cardiovascular magnetic resonance imaging (CMRI) in patients with left ventricular hypertrabeculation (LVHT), also termed “noncompaction.” Currently, several echocardiographic definitions of LVHT exist, and up to now no CMRI-specific diagnostic criteria for LVHT have been developed (2–4). We have, however, concerns and doubts as to whether the current study will clarify the confusion regarding the diagnosis of LVHT.
According to their definition, the investigators found by CMRI that “areas of non-compaction” were common in healthy volunteers, athletes, patients with hypertrophic or dilated cardiomyopathy, and aortic stenosis. Because these findings were not correlated with echocardiographic or anatomic data, how can Petersen et al. be sure that these areas were indeed “noncompacted” and not just the papillary muscles, false tendons, or aberrant bands, which are common cardiac findings (5)?
When assessing the myocardial layers with different degrees of tissue compaction, how did the researchers differentiate myocardium from flow artifacts? Why did they measure the ratio of noncompacted/compacted myocardial layers in diastole and not in systole, as recommended by one of the echocardiographic definitions (3)? How to explain the discrepancy between the relatively smooth endocardial surface as seen on CMRI and the bizarre morphology of trabeculations and deep intertrabecular recesses when examining LVHT patients echocardiographically and at autopsy?
Echocardiography often does not visualize with clarity the left ventricular apex. Thus, we do not understand why this cardiac region, which can be much better visualized by CMRI than by echocardiography, was excluded from measurements. According to the investigators, a ratio of noncompacted to compacted myocardial layers >2.3:1 in diastole distinguished “pathological” from “nonpathological” noncompaction. Why did they then diagnose “partial expression” of the disease in Patient #2, with a ratio of only 1.1? What is the distinction between “nonpathological” noncompaction and “partial expression” of noncompaction? According to which echocardiographic criteria was LVHT-diagnosed in the seven patients? Why were other family members of Patient #4, who had a positive family history, not included? Did any of these relatives suffer from a neuromuscular disorder? According to which type was LVHT transmitted in the families?
Moreover, which neuromuscular disorder was diagnosed in Patient #7? Did the patient undergo only clinical neurological investigations or were invasive procedures also carried out? Were thrombi detected in any of the investigated patients, particularly in Patient #5, who had systemic embolism?
Also, how to explain the pathomechanism of acquired LVHT, where the myocardium was once totally compact? In these cases, pathogenetic explanations other than noncompaction of the embryonic myocardium are required.
In conclusion, the distinction between “normal” and “abnormal” trabeculation is a continuing challenge. Commonly accepted diagnostic criteria for LVHT should be developed based on the correlation of pathoanatomical and imaging findings. The diagnosis of LVHT relies on morphological abnormalities and does not require a positive family history, neuromuscular disorders, embolization, or regional wall motion abnormalities as additional diagnostic criteria.
- American College of Cardiology Foundation
- Petersen S.E.,
- Selvanayagam J.B.,
- Wiesmann F.,
- et al.
- Chin T.K.,
- Perloff J.K.,
- Williams R.G.,
- Jue K.,
- Mohrmann R.
- Jenni R.,
- Oechslin E.,
- Schneider J.,
- Attenhofer Jost C.,
- Kaufmann P.A.