An endoscopic and anatomical approach to the septal papillary muscle of the conus.

Many authors have questioned the gross anatomy of the septal papillary muscle of the conus known as the papillary muscle complex (PMC) during the past century. An anatomical investigation was conducted to identify the morphology and the topography of the PMC. Our study involved 200 formalin fixed adult human hearts. The PMC was present in 82% of the hearts, while in the remaining 18% of specimens, it was replaced by tendinous chords. The PMC was connected with the septal (59.7%), anterior (20.7%), or both septal and anterior leaflets (19.5%) with single (29.8%) or multiple chordae tendinae (70.1%). The PMC was also found to be present as a single papilla (51.8%), double papilla (32.9%) or triple papilla (15.2%). In addition to the PMC, we observed accessory single septal papillary muscles 42 specimens, double septal papillary muscles 32 specimens and triple septal papillary muscles 26 specimens. In the right ventricular inflow tract, the location of the PMC was consistently found to be in a position below the junction of the anterior and septal leaflets of the tricuspid valve. In the right ventricular outflow tract, we were able to identify 73 specimens in which the PMC was located at the junction formed superiorly by the inferior border of the subpulmonary infundibulum and inferiorly by the superior-lateral border of the septal band, extending into the region of the subpulmonary infundibulum. In the remaining 27%, the PMC was located primarily at the area occupied by the superiolateral border of the septal band without extending to the subpulmonary infundibulum. The present study describes the topography of the PMC according to its surrounding anatomical structures such as the tricuspid valve, subpulmonary infundibulum and septal band of the right ventricle. This anatomical data could have important clinical significance for cardiac surgeons operating in this area.

A retroesophageal right subclavian artery originating from the left aortic arch -- a case report and review of the literature.

The retroesophageal right subclavian artery is an anatomical abnormality encountered by anatomists and pathologists and recently interventional cardiologists and thoracic surgeons have also come across this phenomenon. We report a case of a retroesophageal right subclavian artery arising from a normally located left aortic arch in a young male autopsied in the Department of Forensic Service of Warsaw Medical University. In addition to the aforementioned anomaly, the presence of a right non-recurrent inferior laryngeal nerve was noticed. The possible embryonic development of these branching patterns and their clinical significance is discussed.

False tendons: an endoscopic cadaveric approach.

False tendons (FTs) have been extensively described and recognized by gross anatomic studies. However, in the clinical setting the recognition of FTs is limited to the use of echocardiography. We examined 200 formalin fixed adult hearts, with gross dissections. In addition, 90 of these specimens were also examined with ultrasonographic and endoscopic techniques. Gross examination was able to identify FTs in 128 (62%) specimens. The total number of FTs observed, was 248 and was classified into five types according to their location. In Type I (92, 37.1%) the FT was located between the posteromedial papillary muscle and the ventricular septum. In Type II (55, 22.1%) the FT was located between the two papillary muscles. Type III (41, 16.5%) was classified as an FT between the anterolateral papillary muscle and the ventricular septum. The FT in Type IV (31, 12.5%) was observed to connect between the ventricular septum and the free wall and lastly in Type V (29, 11.6%) the FTs were found to be weblike with three or more points of insertion. When using all three techniques (n = 90), gross dissection and endoscopy were able to identify FTs in 62.2% of specimens while echocardiographic imaging was only able to identify FTs in 27.7% of specimens. Of the 114 FTs detected grossly and endoscopically, echocardiography was only able to identify 46 (40.3%). Therefore, the overall sensitivity of echocardiography for detecting left ventricular FTs was only 40.3%, compared to 100% for endoscopy. Based upon the ability or lack thereof of echocardiography to detect certain topographical patterns, we have created a small series of subtypes for the FTs. Histologically, in 30% of the FTs, conduction tissue fiber was observed to be present, which may implicate them in the appearance of arrhythmias.

The relationship of myocardial bridges to coronary artery dominance in the adult human heart.

Myocardial bridging is recognized as an anatomical variation of the human coronary circulation in which an epicardial artery lies in the myocardium for part of its course. Thus, the vessel is 'bridged' by myocardium. The anterior interventricular branch of the left coronary artery has been reported as the most common site of myocardial bridges but other locations have been reported. The purpose of this study was to provide more definitive information on the vessels with myocardial bridges, the length and depth of the bridged segment, and the relationship between the presence of bridges and coronary dominance. Two hundred formalin-fixed human hearts were examined. Myocardial bridges were found in 69 (34.5%) of the hearts with a total of 81 bridges. One bridge was found in 59 of these hearts and multiple bridges were observed in ten (eight with double bridges and two with triple bridges). Bridges were most often found over the anterior interventricular artery (35 hearts). Bridges were also found over the diagonal branch of the left coronary artery (14), over the left marginal branch (five) and over the inferior interventricular branch of the left coronary artery (six). Bridges were also found over the right coronary artery (15 hearts), over the right marginal branch (four) and over the inferior interventricular branch of the right coronary artery (two). The presence of bridges appeared to be related to coronary dominance, especially in the left coronary circulation. Forty-six (66.6%) of the hearts with bridges were left dominant. Forty-two of these had bridges over the left coronary circulation and four over the right coronary circulation. Seventeen hearts (24.6%) were right dominant. Eleven of these had bridges over the right coronary circulation and six over the left coronary circulation. The remaining six hearts were co-dominant with four having bridges over the left coronary circulation and two over the right coronary circulation. The mean length of the bridges was 31 mm and the mean depth was 12 mm. The possible clinical implications of myocardial bridging may vary from protection against atherosclerosis to systolic vessel compression and resultant myocardial ischaemia.