Anatomical Study of the Cardiac Veins and their Tributaries in Bovines (Bos indicus) in Comparison with Humans and Other Animal Species / Estudio Anatómico de las Venas Cardiacas y sus Tributarias en Bovinos (Bos indicus) en Comparación con Humanos y Otras Especies Animales

SUMMARY: In bovines, anatomical observations of the coronary vascular tree describe qualitative characteristics. The objective of this study was to morphometrically characterize the coronary veins and their tributaries in cattle. An arcuate application with 2.0 silk was performed around the ostium of the coronary sinus of 28 bovine hearts and a number 14 catheter was placed, through which semi- synthetic polyester resin and mineral blue color was perfused. In 22 hearts (78.6 %) the great cardiac vein was originated at the cardiac apex. The configuration of the arteriovenous trigone was mainly closed inferior and superior types (50 %). The caliber of the great cardiac vein at the level of the atrioventricular sulcus was 6.7 +/- 1.2 mm. The origin of the left marginal vein was observed in the lower third of the left cardiac margin (53.6 %), its distal caliber was 4.1 +/- 0.8 mm and its drainage was at the level of the great cardiac vein. The middle cardiac vein originated from the cardiac apex in 78.6 % of the samples, emptied mainly into the coronary sinus (82.1 %) and its distal caliber was 4.7 +/- 0.9 mm. Anastomoses occurred in 28.6 % of the hearts, being found in most cases between the middle cardiac vein and the great cardiac vein (50 %), which was significant compared to other anastomoses (p<0.001). The length of the coronary sinus was 42.2 +/- 5.1 mm, its distal caliber was 13.8 +/- 2 mm, and its shape was cylindrical. Myocardial bridges were found in 3 hearts (10.7 %) mainly in the lower third of the middle cardiac vein (66.6 %). Most of the main coronary veins drained into the coronary sinus, with some cases with atypical outlets and the presence of a high percentage of anastomosis that serves to improve cardiac venous drainage in case of venous compression or obstruction.

En bovinos, las observaciones anatómicas de árbol vascular coronario describen características cualitativas. El objetivo de este estudio fue caracterizar morfométricamente las venas coronarias y sus tributarias en bovinos. Se realizó una aplicatura arciforme con seda 2.0 alrededor del ostium del seno coronario de 28 corazones de bovino y se colocó un catéter número 14, a través del cual se perfundió resina de poliéster semisintética y color azul mineral. La vena cardiaca magna se originó en 22 corazones (78,6 %) en el ápex cardiaco. La configuración del trígono arteriovenoso fue principalmente cerrado inferior y superior (50 %). El calibre de la vena cardiaca magna a nivel del surco atrioventricular fue 6,7 +/- 1,2 mm. El origen de la vena marginal izquierda se observó en el tercio inferior del margen izquierdo cardiaco (53,6 %), su calibre distal fue 4,1 +/- 0,8 mm y su desembocadura fue a nivel de la vena cardiaca magna. La vena cardiaca media se originó en el ápex cardiaco en el 78,6 % de las muestras, desembocó principalmente en el seno coronario (82.1 %) y su calibre distal fue 4,7 +/- 0,9 mm. Se presentó anastomosis en el 28,6 % de los corazones, encontrándose en la mayoría de los casos entre la vena cardiaca media y la vena cardiaca magna (50 %), lo cual fue significativo en comparación con otras anastomosis (p<0,001). La longitud del seno coronario fue 42,2 +/- 5,1 mm, su calibre distal fue 13,8 +/- 2 mm y su forma fue cilíndrica. Se encontró puentes miocárdicos en 3 corazones (10,7 %) y en el tercio inferior de la vena cardiaca media (66,6 %). La mayoría de las venas coronarias principales desembocan en el seno coronario, con algunos casos con desembocaduras atípicas y la presencia de un alto porcentaje de anastomosis que sirve para mejorar el drenaje venoso cardiaco en caso de compresión u obstrucción venosa.

Anatomy of the coronary sinus with regard to cardiac resynchronization therapy implantation.

Knowledge of the coronary sinus (CS) anatomy is crucial for implantation of cardiac resynchronization therapy (CRT). Obstacles to CS entry, such as the Eustachian ridge and Thebesian valve, as well as within the CS, such as Vieussen's valve and the vein of Marshall, are important to understand and differentiate during implantation or to identify earlier by imaging. Anatomic knowledge is mandatory to select the most suitable side branch for lead implantation. Modern tools and techniques almost always enable other anatomic problems, such as tortuous, small, short, or overly straight side branches, to also be overcome.

Peculiarities in coronary sinus anatomy: implications for successful cannulation from an autoptic study.

AIMS: The number of cardiovascular procedures using the coronary sinus (CS) as a gateway is constantly increasing. The present study aimed to define specific structures within CS, which could potentially complicate CS cannulation and to develop a new Thebesian valve (TV) classification system. METHODS AND RESULTS: The study was performed on 560 consecutive unfixed cadaveric hearts during routine autopsy examination (1-3 days post-mortem). Basic CS dimensions were measured and the presence and dimensions of the TV and the Vieussens valve (VV) were assessed. Thebesian valves were classified according to their morphology into six main types: remnant fold, semilunar, fenestrated, chord, fused strands, and mixed shaped. The median age of hearts was 48 years (range 16-95 years), and 38.9% were female. Thebesian valve was present in 79.5%. The most common TV type was semilunar (54%) followed by fenestrated (8.2%), remnant fold (5.5%), fused strands (4.8%), chord (4.0%), and mixed shaped (3.0%). In 1.1% of hearts, TV totally covered the coronary sinus ostium (CSO). The VV was detected in 67.9%. Potentially occlusive VV was found in 1.1% hearts and in all of which it coexisted with obstructive TV. The median CSO area was 87.9 mm2 [interquartile range (IQR): 56.5-127.1 mm2] and median CS length was 38 mm (IQR: 29.5-45 mm). The CSO area and CS length correlated with each other and with the right atrium's dimensions. CONCLUSION: We identified six types of TVs, among which only 1.1% TVs caused total occlusion of CSO. The obstructive TV co-existed with potentially occlusive VV what might hinder CS cannulation.

Coronary venous anatomy relevant to cardiac resynchronization therapyan angiographic study

Cardiac resynchronization therapy (CRT) in-volves placing a lead through the coronary sinus to pace the left ventricle. However, technical problems arise in the procedure either due to variant anatomy or due to the presence of valves. Information on coronary venous anatomy is scarce in the South Indian population. The aim of this study was to describe the coronary sinus anatomy in patients undergoing CRT implant. Coronary sinus angiograms were used to study the following parameters: (a) Dimensions of coronary sinus (b) Number and distribution of tributaries (excluding middle and great cardiac veins) (c) Diameter of major veins at the origin (d) Angulation of tributaries with CS. Measurements were made using calipers in the dicom viewer. Out of the 24 angiograms studied, only a single tributary of adequate size was noted in 70.8% (17/24) of the cases, which was most commonly a midlateral vein (76.5%). Two prominent tributaries were noted in 29.2% (7/24) of cases. The average diameter of the veins was 3.93 mm and 80.6% of the veins had an obtuse angle of drainage. Anatomical variations in the coronary venous systemin this population suggest that the majority of patients have a single suitable tributary and this is most often the midlateral vein, which is known to have the most favorable outcome. Data obtained in this study will guide clinicians in left ventricular lead placement in the South Indian population leading to greater procedural success

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Presence of the annular ridge and location of the coronary sinus ostium as morphological features ofthe right atrium and interatrial septum in healthy common marmosets (Callithrix jacchus).

To effectively use a common marmoset (Callithrix jacchus) as an experimental animal species, it is critical to establish a normal characteristics and morphology of the organs of the common marmoset. Although gross morphology of the common marmoset heart is reportedly the same as that of humans, little information is available regarding detailed morphology of the right atrium and the interatrial septum. Heart specimens were collected from three male and 10 female marmosets aged 9 to 65 months to determine the morphological features of the right atrium and the interatrial septum. Ten specimens were evaluated morphologically with a stereoscopic microscope in accordance with preparation and investigation methods designed to facilitate evaluation. Three specimens were histologically evaluated after being stained with hematoxylin-eosin, Elastica van Gieson and periodic acid Schiff. An annular ridge that is not present in the human heart was present in the right atrium and the interatrial septum of the common marmoset hearts. Tissue structure of the annular ridge was similar to atrial myocardial fibers. Furthermore, location of the coronary sinus ostium was different to that in humans. Present findings were used to create a schematic view of the annular ridge in the common marmoset heart. In the common marmoset heart, the annular ridge may function as a valve of the superior vena cava ostium, inferior vena cava ostium, and coronary sinus ostium. Present study provides morphological evidence that common marmosets have a valve-like structure in the right atrium.

Coronary Computed Tomography Angiography-Derived Fractional Flow Reserve in Patients with Anomalous Origin of the Right Coronary Artery from the Left Coronary Sinus.

OBJECTIVE: To examine the fractional flow reserve derived from computed tomographic angiography (CT-FFR) in patients with anomalous origin of the right coronary artery from the left coronary sinus (R-ACAOS) with an interarterial course, assess the relationship of CT-FFR with the anatomical features of interarterial R-ACAOS on coronary computed tomographic angiography (CCTA), and determine its clinical relevance. MATERIALS AND METHODS: Ninety-four patients with interarterial R-ACAOS undergoing CCTA were retrospectively included. Anatomic features (proximal vessel morphology [oval or slit-like], take-off angle, take-off level [below or above the pulmonary valve], take-off type, intramural course, % proximal narrowing area, length of narrowing, minimum luminal area [MLA] at systole and diastole, and vessel compression index) on CCTA associated with CT-FFR ≤ 0.80 were analyzed. Receiver operating characteristic analysis was performed to describe the diagnostic performance of CT-FFR ≤ 0.80 in detecting interarterial R-ACAOS. RESULTS: Significant differences were found in proximal vessel morphology, take-off level, intramural course, % proximal narrowing area, and MLA at diastole (all p < 0.05) between the normal and abnormal CT-FFR groups. Take-off level, intramural course, and slit-like ostium (all p < 0.05) predicted hemodynamic abnormality (CT-FFR ≤ 0.80) with accuracies of 0.69, 0.71, and 0.81, respectively. Patients with CT-FFR ≤ 0.80 had a higher prevalence of typical angina (29.4% vs. 7.8%, p = 0.025) and atypical angina (29.4% vs. 6.5%, p = 0.016). CONCLUSION: Take-off level, intramural course, and slit-like ostium were the main predictors of abnormal CT-FFR values. Importantly, patients with abnormal CT-FFR values showed a higher prevalence of typical angina and atypical angina, indicating that CT-FFR is a potential tool to gauge the clinical relevance in patients with interarterial R-ACAOS.

Effect of lead design and pacing vector on electrical parameters of quadripolar coronary sinus leads: The RALLY-X4 study.

BACKGROUND: Various lead designs have been developed to accommodate different coronary sinus anatomies. Our objectives were to compare electrical parameters of straight and spiral left ventricular leads, to evaluate capture thresholds and impedances using different pacing vectors, and to study evolution of thresholds over time. METHODS: The RALLY-X4 study enrolled patients implanted with a lead from the Acuity X4 family (straight, spiral short, or spiral long). Electrical parameters (including capture thresholds from all 17 vectors) were measured at baseline and follow-up. RESULTS: Data from 795 patients who were successfully implanted were analyzed. Straight and spiral leads had similar proportions of patients with thresholds <2.5 V/0.4 ms using the distal electrode (61-65% of patients) or from at least one of the proximal (E2-E4) electrodes (81-83% of patients). Unipolar vectors had significantly lower thresholds and impedances than bipolar vectors, with similar measurements compared to extended bipolar configurations. Capture thresholds increased with more proximal electrodes for all leads. Over a mean follow-up of 1 year, a slight decrease in capture thresholds was observed. CONCLUSION: Straight and spiral quadripolar leads allow to obtain clinically acceptable capture thresholds from at least one of the proximal electrodes in >80% of patients. Pacing vectors significantly affect electrical parameters, with higher thresholds in more proximal electrodes and lower thresholds with unipolar and extended bipolar configurations. Capture thresholds slightly decreased over a mean follow-up of 1 year.

An anatomical investigation of the coronary ostia and its relationship to the sinotubular junction within a select South African population

The coronary ostia (CO) lie within the left and right aortic sinuses, respectively; and are bound by the sinotubular junction (STJ) superiorly. The high frequency of cardiac procedures that require catheterization has necessitated the reappraisal of the anatomy of the origin of the coronary arteries. Therefore, this study aimed to describe the CO by recording its diameter, shape, and relation to the sinotubular junction in a select South African population.The present study included the gross dissection of 50 formalin fixed, adult cadaveric hearts. The average diameter of the right coronary ostium (RCO) was 3.29mm and the left coronary ostium (LCO) was 3.87mm. With regard to the shape of the ostia, the RCO was described as circular in 52% (26/50), horizontally ellipsoid in 24% (12/50) and vertically ellipsoid in 24% (12/50) of cases. The LCO was circular in 30% (15/50), horizontally ellipsoid in 60% (30/50) and vertically ellipsoid in 10% (5/50) of cases. The RCO was located below the STJ in 88% (44/50) and at the level of the STJ in 12% (6/50) of cases. The LCO was recorded below the STJ in 64% (32/50), at the level of the STJ in 32% (16/50) and above the STJ in 4% (2/50) of cases. Multiple ostia arising from a single aortic sinus was recorded in 14% (7/50) of cases. In 2% (1/50) of cases, the RCO was located in the non-coronary sinus. In addition, the RCO arose from the left aortic sinus in 2% of cases. The results of the present study correlate with those of previous studies. Anomalous CO, although asymptomatic has been linked to myocardial infarction and sudden cardiac death. It is, therefore, imperative for the clinician to be aware of variant CO anatomy, which may alert them to the predisposition of cardiac risks

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Observations of foetal heart veins draining directly into the left and right atria.

Evaluation of semiserial sections of 14 normal hearts from human foetuses of gestational age 25-33 weeks showed that all of these hearts contained thin veins draining directly into the atria (maximum, 10 veins per heart). Of the 75 veins in these 14 hearts, 55 emptied into the right atrium and 20 into the left atrium. These veins were not accompanied by nerves, in contrast to tributaries of the great cardiac vein, and were negative for both smooth muscle actin (SMA) and CD34. However, the epithelium and venous wall of the anterior cardiac vein, the thickest of the direct draining veins, were strongly positive for SMA and CD34, respectively. In general, developing fibres in the vascular wall were positive for CD34, while the endothelium of the arteries and veins was strongly positive for the present DAKO antibody of SMA. The small cardiac vein, a thin but permanent tributary of the terminal portion of the great cardiac vein, was also positive for SMA and CD34. A few S100 protein-positive nerves were observed along both the anterior and small cardiac veins, but no nerves accompanied the direct dra- inage veins. These findings suggested that the latter did not develop from the early epicardiac vascular plexus but from a gulfing of the intratrabecular space or sinus of the atria. However, the immunoreactivity of the anterior cardiac vein suggests that it originated from the vascular plexus, similar to tributaries of the great cardiac vein.

Coronary sinus morphology in pediatric patients with supraventricular tachycardia.

PURPOSE: The anatomic basis of atrioventricular node reentrant tachycardia (AVNRT) remains incompletely characterized in children. Differences in coronary sinus (CS) size and morphology have been observed in adults with AVNRT but have not been well characterized in children. METHODS: Children (< 18 years) brought to the EP lab with supraventricular tachycardia for ablation underwent CS venography. A blinded pediatric interventional cardiologist performed CS measurements, which were indexed to body surface area. Patients were excluded if they were < 25 kg or had significant congenital heart disease. RESULTS: Forty-six patients (age 14.2 ± 3.3 years) met inclusion criteria, 17 with AVNRT and 32 with an accessory pathway (AP). CS ostium (LAO projection, end-systole) was 7.8 ± 2.9 mm/m2 for the AVNRT group versus 6.0 ± 2.5 mm/m2 for the AP group (p = 0.04). CS "windsock" morphology was more prevalent in the AVNRT group (16/17, 94.1%) than the AP group (11/32, 34.3%) (p < 0.001). Within the AVNRT group, there was no correlation between CS ostium size and tachycardia cycle length (R = 0.01, p = 0.96), fast-pathway ERP (FPERP) (R = 0.42, p = 0.12), or A2-H2 at the FPERP (R = 0.25, p = 0.39). CONCLUSIONS: Children with AVNRT have larger CS ostia and more prevalent windsock morphology. CS size/morphology did not correlate with EP properties of the AVNRT substrate. These features may explain the basis for the development of the electrophysiologic substrate for dual AV node physiology in children.

Three-dimensional visualisation of coronary sinus ostium from the inside right atrium perspective.

BACKGROUND: There is no in vivo method of coronary sinus visualisation from the right atrium perspective. AIM: The objective of the study was to create a cardiac computed tomography (CT) angiography-based method of visualising the coronary sinus ostium and the Thebesian valve from the inside right atrium perspective. METHODS: In 78 consecutive patients, a cardiac CT angiography (Aquilion 64, Toshiba) with retrospective gating (slice 0.5 mm) was performed. Raw data were reconstructed on Vitrea 2 workstations (Vital Images). In order to create the three-dimensional (3D) coronary sinus visualisation from the "inside view" perspective, patented "Fly Through" algorithms were used, and the anatomical positions on the multiplanar reconstruction images were marked. A dedicated, Likert-based five-point scale was developed and used to evaluate the quality of the visualisations. RESULTS: The average quality of the visualisations of the coronary sinus ostium in two-dimensional multiplanar reconstruction images was good (4.17 ± 0.85 points) and was clinically interpretable in all cases. The image quality of the "inside view" 3D images was 3.61 ± 1.12 points. In 57.7% of cases we obtained high scores (4 and 5 points). The main diameter was 10.72 ± 2.48 mm, and the entrance angle of the coronary sinus into the right atrium was 103.76 ± 10.71°. CONCLUSIONS: Cardiac CT angiography is a useful method that permits the coronary sinus ostium and Thebesian valve to be visualised in vivo from the inside of the right atrium in a comparable manner.

Fiber-reinforced computational model of the aortic root incorporating thoracic aorta and coronary structures.

Cardiovascular diseases are still the leading causes of death in the developed world. The decline in the mortality associated with circulatory system diseases is accredited to development of new diagnostic and prognostic tools. It is well known that there is an inter relationship between the aortic valve impairment and pathologies of the aorta and coronary vessels. However, due to the limitations of the current tools, the possible link is not fully elucidated. Following our previous model of the aortic root including the coronaries, in this study, we have further developed the global aspect of the model by incorporating the anatomical structure of the thoracic aorta. This model is different from all the previous studies in the sense that inclusion of the coronary structures and thoracic aorta into the natural aortic valve introduces the notion of globality into the model enabling us to explore the possible link between the regional pathologies. The developed model was first validated using the available data in the literature under physiological conditions. Then, to provide a support for the possible association between the localized cardiovascular pathologies and global variations in hemodynamic conditions, we simulated the model for two pathological conditions including moderate and severe aortic valve stenoses. The findings revealed that malformations of the aortic valve are associated with development of low wall shear stress regions and helical blood flow in thoracic aorta that are considered major contributors to aortic pathologies.

Morphometry of the coronary ostia and the structure of coronary arteries in the shorthair domestic cat.

The aim of this study was to measure the area of the coronary ostia, assess their localization in the coronary sinuses and to determine the morphology of the stem of the left and right coronary arteries in the domestic shorthair cat. The study was conducted on 100 hearts of domestic shorthair cats of both sexes, aged 2-18 years, with an average body weight of 4.05 kg. A morphometric analysis of the coronary ostia was carried out on 52 hearts. The remaining 48 hearts were injected with a casting material in order to carry out a morphological assessment of the left and right coronary arteries. In all the studied animals, the surface of the left coronary artery ostium was larger than the surface of the right coronary artery ostium. There were four types of the left main coronary artery: type I (23 animals, 49%)-double-branched left main stem (giving off the left circumflex branch and the interventricular paraconal branch, which in turn gave off the septal branch), type II (12 animals, 26%)-double-branched left main stem (giving off the left circumflex branch and the interventricular paraconal branch without the septal branch), type III (11 animals, 23%)-triple-branched left main stem (giving off the left circumflex branch, interventricular branch and the septal branch, type IV (1 animal, 2%)-double-branched left main stem (giving off the interventricular paraconal branch and the left circumflex branch, which in turn gave off the septal branch). The left coronary artery ostium is greater than the right one. There is considerable diversity in the branches of proximal segment of the left coronary artery, while the right coronary artery is more conservative. These results can be useful in defining the optimal strategies in the endovascular procedures involving the coronary arteries or the aortic valve in the domestic shorthair cat.

Geometry of Koch's triangle.

AIMS: The first aim of this study was to determine the size of the Koch's triangle. The second one was to investigate relation between its dimensions and other individual-specific and heart-specific parameters as well as to create universal formula to estimate triangle dimensions based on these parameters. METHODS AND RESULTS: This study is a prospective one, presenting 120 randomly selected autopsied hearts dissected from adult humans (Caucasian) of both sexes (31.7% females), with mean age of 49.3 ± 17.4 years. The length of triangle sides and angles were measured and the triangle area was calculated as well. Sixteen additional heart parameters were measured in order to analyse potential relationship between the dimensions of Koch's triangle and other dimensions of the heart, using linear regression analysis. The mean (±SD) length of the anterior edge was approximated to 18.0 ± 3.8 mm, the posterior edge to 20.3 ± 4.3 mm, and the basal edge to 18.5 ± 4.0 mm. The average values of the apex angle, the Eustachian angle, and the septal leaflet angle were 58.0 ± 14.4°, 53.8 ± 10.6°, and 67.6 ± 14.4°, respectively. The mean value of the Koch's triangle area was 151.5 ± 55.8 mm2. The 95th percentile of triangle's height (the distance from the apex to the coronary sinus) was 21.8 mm. CONCLUSION: Mean values and proportions of triangle's sides and angles were presented. Koch's triangle showed considerable individual variations in size. The dimensions of the triangle were strongly independent from individual-specific and heart-specific morphometric parameters; however, the maximum triangle's height can be estimated as 22 mm.

Spatial relationship of coronary sinus-great cardiac vein to mitral valve annulus and left circumflex coronary artery: implications for cardiovascular interventional procedures.

BACKGROUND: The spatial relationship of the coronary sinus-great cardiac vein (CS-GCV) to free posterior portion of the mitral valve annulus (MVA) and left circumflex coronary artery (LCx) has gained importance with the advent of cardiovascular interventional procedures such as percutaneous transvenous mitral annuloplasty (PTMA) and mitral isthmus (MI) ablation. METHODS: In 50 normal (nondilated cardiomyopathy, or non-DCM) and 20 dilated cardiomyopathy (DCM) cadaveric hearts, the diameter and distance from the MVA of CS-GCV and its spatial relationship to LCx along the free posterior portion of the MVA were studied. RESULTS: The diameter of the CS-GCV increased from the beginning to termination in both non-DCM and DCM cases. The CS-GCV was located farthest from the MVA in the vertical plane in the middle of its course and in the horizontal plane at its beginning. The LCx was located above the CS-GCV in direct contact with the epicardial aspect of MI in 12% non-DCM and 15% DCM cases and was wedged between the CS-GCV and MI in 20% non-DCM and 15% DCM cases. CONCLUSIONS: Knowledge of the separation between the CS-GCV and MVA in the horizontal and vertical planes could help in selecting suitable candidates and the preprocedural prediction of success of PTMA. Awareness of the spatial relationship of LCx with CS-GCV in MI would help to reduce the risk of incomplete MI block due to a heat sink effect or damage to the LCx by direct thermal injury during MI ablation.

Variation of anatomical structures related to biventricular pacing procedures and cannulation of the coronary sinus.

The success of biventricular pacing procedures is at least partially related to the ability to implant leads into the heart. Lead placement into the coronary sinus can be particularly challenging because of variations in the coronary venous anatomy. We examined the anatomy of the coronary sinus and the Thebesian valve. Forty-three (22 male, 21 female) embalmed adult cadavers were used to determine the internal diameter of the coronary sinus ostium, the presence of a membranous or fenestrated Thebesian valve, and the percent occlusion of the coronary sinus ostium by the Thebesian valve, if present. An 8-French (F) guiding catheter was used to simulate coronary sinus cannulation. The average internal diameter of the coronary sinus ostium was 11.44 ± 3.21 mm. A Thebesian valve was present in 74 % of the cadavers, and the majority (84 %) of those valves were membranous. In the presence of a Thebesian valve, the opening at the ostium was reduced to 7.47 ± 2.69 mm. The percent occlusion of the coronary sinus ostium by the Thebesian valve varied from 8.26 to 100 %. The average cannulation distance (length of catheter travel into the coronary sinus from the coronary sinus ostium) was 69 ± 18 mm. Statistical analyses revealed no gender differences in the measurement data for either the coronary sinus or Thebesian valve. The most common presentation is a membranous Thebesian valve. Most frequently, the percent occlusion ranged between 41 and 50 %. The cannulation distance was greater in males than in females.

Introducer Development for Coronary Sinus Access From Parasternal Mediastinotomy.

OBJECTIVE: Right parasternal mediastinotomy with right atriotomy has been used clinically for pacemaker insertion. A similar approach might facilitate access to the coronary sinus for biventricular pacing and other manipulations when more conventional approaches are not feasible. The primary barrier to this is lack of appropriate introducers and techniques. METHODS: Anatomically derived introducers were developed in 2 anesthetized domestic pigs using data from computerized axial thoracic tomography. Each digitized tomogram defined a unique introducer shape and was constructed using 3-dimensional (3D) modeling software and printing. Each parent pig then underwent surgery demonstrating coronary sinus lead insertion, using its custom-configured introducer. Next, with institutional review board approval, 65 patients were identified who had undergone conventional endocardial coronary sinus lead insertion followed by thoracic scanning. These tomograms were used to design appropriately curved introducers for human anatomy. RESULTS: Fifty-one introducer paths were defined following anatomic pathways and avoiding bends inconsistent with materials used for commercial peel-away introducers. Each path was defined by a bend and distance toward the coronary sinus ostium and a hook and twist out of plane to align with the local orientation of the coronary sinus. The average dimensions were the following: distance, 67 mm; bend angle, 47 degrees; hook angle, 39 degrees; and twist angle, 20 degrees. A prototype cannula was tested for fit in a fresh frozen postmortem human specimen. CONCLUSIONS: Parasternal mediastinotomy access to the coronary sinus for cardiac resynchronization, mitral annuloplasty, and instrumentation is feasible. Human computerized tomographic scans can be used to define curvatures and dimensions for marketed introducers.