The incorrect notion of the ‘unique myocardial band’

The recent editorial by Buckberg [1] on the topic of right ventricular failure subsequent to cardiac surgery contains, in our opinion, inaccurate anatomical descriptions of the heart. In his editorial, the author promotes the oversimplified assertion that the myocardial mass is arranged on the basis of the unique myocardial band. He may well be correct that the results reported by Couperus et al. [2] reflect ‘a problem with the surgery’ and correct in his criteria for contraindicating surgical ventricular restoration. We are insufficiently qualified to pass expert judgement on this issue. These points, however, are presented in the setting of the alleged myocardial band. This aspect is now pertinent, as 2 reviews published in the first issue of the journal for 2018 have provided evidence from multiple sources showing that the ventricular mass is not organized on the basis of the ‘unique myocardial band’ [3, 4]. It is true that the cardiomyocytes are attached one to the other so as to produce opposing endocardial and epicardial helical formations. This fact, however, has been known for centuries, with Pettigrew, for example, pointing out that the myocardium was not arranged in the fashion of skeletal muscle. It is significant that, to the best of our knowledge, the author himself has made no attempt to validate the anatomical arrangement as depicted in his model. If the cardiomyocytes were truly arranged as suggested, then the boundaries between the alleged components of the unique band would be revealed by histological studies. There are no such studies providing the necessary validation. More recent techniques, such as diffusion tensor imaging and microcomputed tomography, as shown in our recent review [3], have produced results which are in keeping with the notion that the ventricular cardiomyocytes are aggregated so as to form a complex 3-dimensional mesh. Such an arrangement, validated using these techniques [3, 4], is incompatible with the notion of the ‘unique myocardial band’. In this regard, it is noteworthy that, in light of such new evidence, previous supporters of ‘the band’ are now posing the question as to the nature of the ‘real’ ventricular architecture [5], stating that the model based on the helical heart ‘ignores important aspects of ventricular anatomy and should probably be replaced’. This is particularly pertinent to the part of the current editorial that describes the architecture of the right ventricle, which states that ‘The RV free wall is formed by a wrap of transverse fibres that produce constriction or compression, whereas oblique helical fibres form the septum that will twist as they coil to shorten.’ Such a description ignores important findings regarding the transmural architecture of the right ventricle [6]. Acceptance of this assertion could lead the reader to the false assumption that the transmural helical arrangement is absent in this region. As the author has commented in his editorial ‘anatomy is our friend, not our enemy’. This statement holds true only when the anatomical findings are based on all the available information. The author also quotes physicist Neil de Grasse Tyson who stated that ‘the good thing about science is that it’s true whether or not you believe in it’. We agree with this statement, but suggest that science is a dynamic medium, in which our understanding is constantly changing based on the presentation of new data and evidence. Such new evidence [3, 4] has now been presented to disprove the concept of the unique myocardial band. It should not be ignored either by scientists or clinicians.