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The morphology of myocardial bridges (MB) in the heart of the domestic pig remain an open issue. Despite numerous analyses of the subject, many controversies still exist. Opinions also differ when the influence of the MB on haemodynamic processes in the coronal vessel system is concerned. In the examined group of 150 domestic pig's hearts, the length of the detected MB varied from 1.8 to 39.7 mm while their thickness amounted to 0.8 - 4.7 mm. Both the longest and the thickest bridges were connected with the posterior interventricular branch. It was noticed that the MB muscle bands cross the long axis of the vessels located in the grooves mostly at almost a right angle. Three forms of perivascular space were educed using the criterion of the distance of the vessel from the surrounding muscularis externa.
One of the hypotheses put forward concerning the mechanism of vasovagal syncope is that the vagal afferent fibres are activated during vigorous contractions against a partly empty left ventricle. The aim of the study was to confirm this hypothesis by using 2D echocardiography during a head-up tilt test. The study was carried out on 39 patients (17 male, 22 female, age range 21–64 years), all with a history of recurrent syncope. The patients were examined using a 2D echo to measure the end-diastolic and end-systolic volume before the head-up tilt test after the Westminster protocol (45min/60 grade) and every five minutes after tilting. T patients during head-up tilt test had a positive response and 32 proved negative. A reduction of both the end-diastolic and end-systolic volumes of the left ventricle was noticed. There was no significant difference in the degree of ejection fraction reduction. The difference in ejection fraction reduction between the two groups was similarly non-significant. It was also noticed that the patients with a positive response had more vigorous contractions than those with a negative test. The decision was therefore taken to use a different parameter for the left ventricle contraction, namely the LV posterior wall slope. As this parameter is partly dependent on time, its use in confirming the extremely vigorous nature of the contractions was considered appropriate. Only 6 patients were tested using this parameter. A tendency towards greater left ventricle posterior wall slope values, both before and during tilting was noticed in the group of patients with vasovagal reaction. Our data shows that vigorous contraction is probably less responsible for vasovagal syncope release than left ventricle volume reduction.
The majority of anatomical structures within the heart during typical atrial flutters’ ablation, right sided accessory pathway ablation or slow pathway ablation are invisible or blurred. Therefore it is very important to know in details interior right atrial structures during such procedures. In the neighborhood of coronary sinus orifice small concavity is visible. This area, called subthebesian fossa, is placed between the os of coronary sinus, the orifice of vena cava inferior and tricuspid annulus. The fossa is on the way of typical atrial flutters’ reentrant circuit and is placed next to the isthmus area, which has become a target site for ablative therapy. Regarding the facts mentioned above we decided to examine the topography of this concavity in relation to neighboring structures. Research was conducted on material consisting of 45 human hearts of both sexes, from 19 to 71 years of age. The hearts came from patients whose death was not cardiologic in origin. The topography of the fossa was examined in relation to coronary sinus orifice (diameter A), vena cava inferior orifice (diameter B) and the attachment of the posterior leaflet of the tricuspid valve (diameter C). Besides we measured two perpendicular sizes in the inlet plane of the fossa. There were the longest size (diameter D) and the shortest size of the fossa (diameter E). We also defined deepness of the fossa (diameter F). Diameter A was from to 2 to 7 mm (avg. 4.9 ± 1.4 mm), diameter B from 2 to 8 mm (avg. 4.0 ± 1.6 mm) and diameter C from 5 to 9 mm (avg. 7.0 ± 1.5 mm). The longest size in inlet plane of the concavity (diameter D) was from 12 to 18 mm (avg.14.1 ± 1.7 mm) and shortest size (diameter E) was from 7 to 14 mm (avg. 9.0 ± 1.7 mm). The deepness of the fossa (diameter F) was from 2 to 7 mm (avg. 4.8 ± 1.2 mm). The subthebesian concavity is inconstant anatomical structure, occurring in all forty five examined hearts (100%). The shape and sizes of the subthebesian fossa were variable in examined group of hearts. Our data suggest that differences in diameters between subthebesian fossa and neighboring structures may have clinical importance during ablation procedure.
Cardiac arrhythmias have troubled patients and fascinated physicians for centuries. The twentieth century was an era of progress, when the mechanism of cardiac disorders became more commonly recognised. Arrhythmias may be due to abnormalities of automaticity, to abnormalities of conduction, or to a combination of both. In order for re-entry to occur, an area of slowing conduction combined with unidirectional block must be present. Much investigation has centred on the underlying re-entry mechanisms of atrial flutter. In the light of these facts, it would seem that a close acquaintance with the detailed topography of the vena cava orifice (cavo), coronary sinus orifice (sinus) and the attachment of the septal leaflet of the tricuspid valve (tricupid) area could be of great interest, especially for invasive cardiologists. The research was conducted on material consisting of 41 hearts of humans of both sexes from the age of 12 to 80 (6 female, 35 male). Classical macroscopic methods of anatomical evaluation were used. The following measurements were made: the shortest distance between the Eustachian valve and the attachment of the tricuspid valve on the left margin of the coronary sinus orifice (diameter 1), the distance between the attachment of the tricuspid valve and the inferior margin of the sinus orifice (diameter 2), the distance between the Eustachian valve and the attachment of the tricuspid valve on the right margin of the coronary sinus orifice (diameter 3), the distance between the inferior margin of the vena cava inferior and the attachment of the tricuspid valve (diameter 4) and, finally, the diameter between the attachment of the septal cups of the tricuspid valve and the external border of the vena cava inferior (diameter 5). No correlation was found between the age and sex of the three groups of the material. The dimensions of the structure examined were similar in the three groups of hearts. In young adult hearts all the diameters measured ranged from 4 to 47 mm The average diameters were, respectively: 15.02 mm (diameter 1), 8.97 mm (diameter 2), 17.27 mm (diameter 3), 26.87 mm (diameter 4), 36.42 mm (diameter 5). In the mature adult hearts all the diameters measured ranged from 8 to 45 mm: 18.19 mm (diameter 1), 10.54 mm (diameter 2), 19.95 mm (diameter 3), 28.90 mm (diameter 4), 39.63 mm (diameter 5). In the older adults hearts all the diameters measured ranged from 4 to 47 mm. The average diameters were, respectively: 15.65 mm (diameter 1), 8.70 mm (diameter 2), 7.25 mm (diameter 3), 26.80 mm (diameter 4), 35.85 mm (diameter 5).
Atrioventricular nodal reentry tachycardia base on reentry circulation in nodal- -perinodal area. The radical treatment of choice is radiofrequency ablation. Procedure approached from the anterior-superior (fast) region sufficient a few seconds of energy delivery for success, however this can result in A-V block. The possibility that arrhythmias substrate may lie very superficially (success of ablation) and damage the normal structures (complication) in the perinodal region must be considered. In order to confirm this hypothesis we examined the autopsy material of 100 normal hearts, both sexes from 18 to 105 years of age (control) and 50 hearts with A-V total block 45–95 years of age (block). We paid attention to the morphology of the nodal artery (NA), atrial inputs (AI) and transitional inputs (TI). It was observed that NA at the level of the central fibrous body was positioned in 94% in the central and in 6% in the inferior part of Koch’s triangle. It was removed from the endocardium 3–6 mm in control and 2–5 mm in block group respectively (NS). In the perinodal area we distinguished AI that directly joined the A-V compact node: superficial (right part of the interatrial septum) or deep (left part). The former occurred in 100% of controls and in 80% of block groups (NS), and the latter in 80% of control group and in 34% in block respectively (p < 0.05). The real substrate of arrhythmia in anterior-superior region lies very superficially and far from the conduction tissue; NA in examined hearts was lying deep beneath the endocardium; ablation close to the node could result in A-V block.
The atria are highly complex multidimensional structures composed of a heterogeneous branching network of subendocardial muscular bundles. The relief of the inner part of the right atrium includes the crista terminalis as well as multiple pectinate muscles that bridge the thinner atrial free walls and appendages. However, a handful of studies have focused attention on the role of the naturally occurring complexities of the atrial subendocardial muscle structures in the mechanisms of cardiac arrhythmias. In accordance with the facts mentioned above, it was decided to examine the morphology and topography of the external interatrial junctions and related structures in order to define the possible anatomical basis of impulse propagation in focal atrial fibrillation. Research was conducted on material consisting of 15 human hearts of both sexes (female — 6, male — 9) from 18 to 82 years of age. In addition we were concerned, on the basis of the history and electrocardiograph tracings, that none of the patients had shown focal and non-focal type of atrial fibrillation. The classic macroscopic methods of anatomical evaluation were used. The walls of the atria were prepared via a stereoscopic microscope, the pericardium and fatty tissue were eliminated from the surface of the atria, visualising muscle fibres linking both of the atria, and the beginnings and the endpoints of fascicles in the right and left atrium were estimated. The structure, large muscle bundle, was present in all examined hearts. The muscle fascicle was descending from the anterior wall of the right atrium just below the orifice of the superior vena cava. The fascicle, running towards the left atrium, divided into two branches, one of which joined with the superior fascicle from the posterior wall and created one running above the interatrial septum and infiltrating into the wall of the left atrium on its superior surface between the superior pulmonary veins. The other branch of the anterior fascicle was running across the anterior wall of the atria and it penetrated into the left atrium muscle in the region of the inferior pole of the left auricle outlet. On the posterior wall of the atria three types of interatrial fascicles were distinguished: unifascicular, bifascicular and trifascicular. The bifascicular type was the most frequent configuration (9 cases — 60.0%), in 5 cases it was trifascicular (33.3%) and finally the unifascicular configuration was observed in just 1 heart (6.7%). On the basis of our study we can conclude that the external interatrial fascicles are the constant structure of the heart, although they may have a variable morphology. Those structures could be responsible for physiological conduction between the atria and may play an important role in patients with atrial fibrillation.
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