Coronary Sulcus Research Articles

Great cardiac vein variations.

A novel variation in the relationship of the great cardiac vein to the circumflex artery was observed in an otherwise normal cadaver heart. Vessels originated and terminated normally, but in their midcourse they were twisted around each other such that each made one complete loop around the other. This variation did not seem to be involved in any pathologies. Variations in the course of the great cardiac vein have been little studied until recently, but their simplicity emphasizes the uniqueness of our intertwined case. Commonly, the great cardiac vein varies with respect to presence, location, and the superficial or deep relationship of single crossings of the anterior interventricular and circumflex arteries. Although rare, the intertwined variation described in the present case may have important basic science implications for understanding mechanisms of vasculo-angiogenesis, and clinical implications for catheter-based procedures and surgeries in the region of the coronary sulcus. Also, a review of great cardiac vein variations is presented herein.

Morphological Features of External Genitalia in Hypospadiac Rat Model: 3-Dimensional Analysis

We examined 3-dimensionally the process of external genitalia formation in the experimental hypospadiac rat model. We administered 7.5 mg flutamide daily, a blocker of androgen receptor, into the abdomen of naturally pregnant female Sprague-Dawley rats from gestational days 14 to 20 to produce a hypospadiac rat model. The control group consisted of male offspring not exposed to flutamide. The fetal phallus was obtained at gestational days 17.5, 19.5 and 21.5. We observed them by scanning electron microscopy. In the 17.5-day-old embryo the projection on the ventral side of the phallus was observed from the base of the phallus to the coronary sulcus in the control rat. This finding demonstrated that the urethra develops from the base of the phallus to the coronary sulcus. On the other hand, this projection was not observed in the hypospadiac rat and the urethra was not seen on the ventral side of the phallus. In the 19.5-day-old embryo the ventral preputial closure appeared in the proximal phallus of the control rat but not of the hypospadiac rat. In the control rat the scrotum was discerned in the perineum and divided by a median fold (the raphe). The raphe reached the base of the phallus, where it was concurrent with the preputial fold that covers the urethra. On the other hand, the hypospadiac rat did not have a raphe and the hollow at the base of the phallus appeared to give rise to the future orifice of the urethra. In the 21.5-day-old embryo the control rat prepuce completely surrounded the distal phallus, whereas that of the hypospadiac rat was dorsally hooded with a ventral cleft and the external appearance resembled the morphology of human penoscrotal hypospadias. This hypospadiac rat model is considered valuable for further studying penile growth and differentiation, and the molecular mechanisms in external genitalia formation in hypospadias.

Investigation of coronary arteries in the porcupine (Hystrix cristata) by latex injection and angiography

Coronary arteries were investigated in the porcupine by means of angiography performed on each of 5 adult porcupines (3 male, 2 female) which was followed by injection of a colored latex mixture from the aortic arch for the demonstration of these arteries. The results showed that the aorta branched out at the level of the cardiac outlet to form the left and right coronary arteries and right ramus coni arteriosi. Coronary arteries coursed and ramified in the myocardium. The left coronary artery divided to form the paraconal interventricular artery and left circumflex artery when it reached the coronary sulcus. The interventricular septum was vascularized by the septal branch of the paraconal interventricular artery and by the small septal branches. The left and right coronary arteries gave off all the branches reported in the literature for other species. When the ramus coni arteriosi originates from the right coronary artery, it is designated a third coronary artery. In conclusion, it was found that the coronary arteries of the porcupine had an "intramyocardial course" as in other rodents. The coronary supply of the heart represented a "left coronary type" which was similar to those of carnivores and ruminants. The results of this study may contribute to the data in this area of science.

Studies on coronary arteriopathy in dogs following administration of CI-1020, an endothelin A receptor antagonist.

A selective nonpeptide endothelin A (ETA) receptor antagonist, CI-1020, was administered to beagle dogs intravenously (i.v.) for 4 hours to 4 weeks. One animal/sex received CI-1020 at 1 mg/kg/hr intravenously for 4, 8, or 24 hours to investigate onset of arteriopathy. Control animals (1/sex) received the vehicle only. To determine reversibility of arteriopathy, 8 dogs/sex were given CI-1020 at 1 mg/kg/hr for 4 days. Two dogs/sex were sacrificed 1, 3, 8, and 29 days following cessation of infusion. Lesion development with prolonged exposure was investigated in 1 male dog. It was given CI-1020 by i.v. bolus at 120 mg/kg/day for 4 weeks and Monastral blue dye was administered i.v. to facilitate localization of vascular lesions. Coronary blood flow was determined in 4 dogs infused with CI-1020 at 0.3, 3, and 30 mg/kg for one hour at each dose. Macroscopically, hemorrhage or blue discoloration of Monastral blue was noted in the extramural coronary arteries along the coronary groove and atrium. Histologically, the earliest coronary changes were noted in animals sacrificed after 24 hours of treatment and characterized by medial hemorrhage and necrosis with a few infiltrating neutrophils. In the reversibility study, incidence and severity of arteriopathy was dependent on time of sacrifice following cessation of infusion. Acute necrotizing inflammation of arteries was present in all animals (n = 4) on day 1 postinfusion, whereas on day 8 postinfusion, lesions characterized by medial small pockets of trapped red cells, cell debris, and adventitial thickening were seen in 1 dog/sex. By day 29 postinfusion, coronary arteries were similar to controls. In the dog given daily i.v. bolus injections of CI-1020 for 4 weeks, arterial inflammatory lesions varied from acute to chronic, although most lesions were considered chronic active. Monastral blue pigments were noted in the wall of most arteries with chronic or chronic active lesions. Acute lesions were similar to those noted in day 1 postinfusion of the reversibility study. Medial smooth muscle necrosis and/or fibrosis with mixed inflammatory cell infiltrates characterized chronic or chronic active lesions. Smooth muscle proliferation and migration into the intima were also noted. There were no significant changes in coronary blood flow, coronary vascular resistance, or mean arterial blood pressure following CI-1020 infusion for 3 hours. In the 24-hour infusion study, plasma endothelin 1 (ET-1) levels were mildly elevated (1.5-4 fold) during CI-1020 infusion when compared to either pretest or control values. These results indicate that administration of endothelin antagonist (CI-1020) to dogs was associated with development of coronary arteriopathy, which was completely resolved within 29 days following cessation of treatment. With prolonged (4-week) CI-1020 treatment, arterial lesions at varying stages of development (acute, chronic active, chronic) were seen, suggesting that tolerance to treatment (up to 4 weeks) does not occur.

The anatomy of the coronary sinus and its tributaries

The coronary sinus and its tributaries were studied by anatomical dissection in 37 adult human cadaveric hearts, which had been fixed in formalin solution. An anastomosis of approximately 1.0 mm in calibre was observed between the anterior and posterior interventricular veins in 19% of specimens. Myocardial bridges were detected above the anterior interventricular vein or its tributaries in 8% of specimens. The great cardiac vein formed the base of the arteriovenous trigone of Brocq and Mouchet with the bifurcating branches of the left coronary artery in 89% of specimens and formed an angle accompanying these arterial branches in 11%. In the trigone the anterior interventricular and great cardiac veins were superficial to the arteries in 73% of specimens. The left marginal vein was present in 97% of specimens, emptying into the great cardiac vein in 81% of cases and into the coronary sinus in the remaining 19%. The small cardiac vein was present in 54% of specimens. In the coronary sulcus the great cardiac vein was adjacent to the circumflex branch of the left coronary artery in 76% of specimens and to the right coronary artery in 5%: in 19% there was no relationship with either artery. The coronary sinus maintained a relationship with the right coronary artery in 46% of specimens and with the left coronary artery in 32%: in 22% it had no relationship with these vessels.

Localization of sympathetic, parasympathetic and sensory neurons innervating the heart of the Beijing duck by means of the retrograde transport of horseradish peroxidase.

Sympathetic, parasympathetic and sensory neurons were labeled by injections of horseradish peroxidase into various regions of the heart in 33 Beijing ducks. Sympathetic postganglionic neurons innervating the heart were located in the paravertebral ganglia C15 (C16 is the last cervical segment in the duck) to T3, especially in the ganglion T1. The coronary sulcus and ventricle were more abundantly innervated by sympathetic neurons than the atrium. The left side of the heart was preferentially innervated by sympathetic postganglionic neurons in the left side of paravertebral ganglia but the right side of the heart were equally supplied from the right and left ganglia. Within the medulla oblongata, the number of labeled vagal preganglionic neurons in the nucleus ambiguus was much greater than that in the dorsal motor nucleus of the vagus nerve. Labeled neurons of the nucleus ambiguus were found in many ducks injected into the coronary sulcus. Cardiac sensory neurons were observed in the dorsal root ganglia C15 to T2 (highest in the ganglion T1) and in the nodose and jugular ganglia of the vagus nerve. These labeled neurons probably form the afferent and efferent limbs of cardiac reflexes and control circulation in the Beijing duck.

Prevalence, vasculature, and innervation of myocardial bridges in dogs

SUMMARY Objective To report gross anatomic examination of the canine myocardial bridge (MB), a muscular band found above the coronary artery (CA), with respect to its occurrence, location, vascularization, and innervation. Sample Population 629 canine hearts obtained within 1 to 3 hours after euthanasia. Procedure After an incision was made at the left fifth intercostal space, the pericardial sac was cut open, and if an MB was present, the heart, lungs, and annexed structures were removed together and subsequently subjected to macroscopic examination of MB musculature and innervation after formalin fixation. Vascular casting was performed by use of methyl methacrylate perfusion. Results Of the 629 canine hearts examined, 189 (30%) had MB, occurrence of which was independent of sex, age, and breed. Among 13 MB-containing specimens examined in detail, there was great variation in thickness (0.11 to 2.24 mm; mean, 0.45 mm) of MB and distance (24 to 236 μm; mean, 103 μm) between the MB and the paraconal interventricular branch of the left CA (PIBL). One pair or 2 pairs of blood vessels from the PIBL supplied the MB muscle. Venous blood returned to the coronary circulation via the branches of the great coronary vein coursing on both sides of the PIBL, in close contact with the PIBL and the groove wall. The 2 veins rejoined at the upper portion of the PIBL and passed obliquely to the coronary groove under the left auricle, and finally drained the blood through the coronary sinus into the right ventricle. Innervation to the MB muscle was derived from nerve branches of the middle cervical ganglion and left vagus nerve. Conclusion Prevalence and localization of MB in dogs and human beings are similar. Vascularization of the MB muscle originates from the PIBL. The cervical ganglion and vagus nerve control the MB muscle. (Am J Vet Res 1997;58:1209–1215)

Morphogenesis of the human external male genitalia.

The morphogenesis of the external genitalia of human fetuses (16-250 mm crown-rump [CR] length, 6-26 weeks of gestation) obtained after medical termination of pregnancy were studied. Differential development (male/female) started after 50 mm CR length (9 weeks). At that time the external genitalia consisted of a cylindrical genital tubercle 2 mm in length with a visible coronary sulcus and glans and genital swellings on either side. A groove on the ventral aspect of the genital tubercle extended to the coronary sulcus; the lateral boundaries of this groove separated to form the urethral folds. In male fetuses the free edges of the urethral folds fused, starting from the proximal end, to form a tunnel over the ventral aspect of the phallus. The pelvic urethra opened into this tunnel, slightly distal to its origin. The mesodermal tissue forming the genital swellings migrated ventrally and then medially. As medial migration started, the skin in the midline between the genital swellings was raised up as a skin fold, which subsequently, as the genital swellings migrated further, became elevated. The proximal part of the tunnel formed by fusion of the urethral folds (proximal to the point of entry of the pelvic urethra) also was compressed and pushed out as the genital swellings fused in the midline over the root of the phallus. These changes took place at between 80 and 110 mm CR length (12-13 weeks' gestation); at this stage the phallus appeared short and was bent ventrally. With further growth and caudal migration of the scrotum, the phallus lost its ventral curvature. The appearance of the external genitalia at different gestational ages bore a close resemblance to that in children with hypospadias. We therefore conclude that hypospadias can be explained on the basis of an embryological arrest due to the absence of the required stimulus for male phenotypic development at the appropriate time.

Cortico-cortical mediation of short-latency (lemniscal) sensory input to the motor cortex in deeply pentobarbitone anaesthetized cats.

In pentobarbitone-anaesthetized cats, responses were recorded as surface positive potentials in the motor cortex on forelimb and brachium conjunctivum stimulation. In such a preparation, the forelimb nerve responses are mediated via the spino-cervical tract and the dorsal column-lemniscal pathway. Lesions of the sensory cortex (sparing only the depth of the coronary sulcus) abolished or reduced short-latency peripheral responses, in the motor cortex, on both skin and muscle nerve stimulation to less than 10% of control, while brachium conjunctivum responses were unchanged. Lesions of the second somatosensory area alone reduced the motor cortex responses on peripheral nerve stimulation by 10-20%. When the sensory cortex was inactivated by spreading depression, peripheral responses in the motor cortex were abolished before the spreading depression reached the recording point, as judged from the brachium conjunctivum response. The depth distribution of positive and negative field potentials, constituting the early components of a peripheral response in the motor cortex, closely resembled that of a cortico-cortical response evoked on stimulation in area 3. It differed from that of thalamo-cortical response evoked on brachium conjunctivum stimulation. These data suggest that most, if not all, sensory input through the dorsal column and spino-cervical tract to the motor cortex is mediated via the sensory cortex.

Left ventricular endocardial proliferation in chickens.

Left ventricular endocardial proliferation in chickens.

Penile vein ligation for venogenic impotence.

We have performed penile vein ligation on 35 patients with venogenic impotence from July 1989 to December 1991. The criteria for surgery were (1) age less than 60 years; (2) negative vasoactive agent intracavernous injection but normal penile arterial function, and (3) abnormal venous leakage documented by dynamic infusion cavernosometry and cavernosography. The procedure in venous ligation is excision of the deep dorsal vein from coronary sulcus to pubic arch, and ligation of cavernous veins after identification. The average follow-up was 27.5 months (range 12-37 months) for 30 patients. The 2 patients who revealed no erection at all immediately after operation had dense adhesion of penile hilar region caused in one case by severe pelvic trauma and in the other by pubic bone fracture. Twenty-eight (93.3%) patients were found to sustain excellent erection within 3 months postoperatively. However, only 12 (40.0%) patients sustained spontaneous erection at long-term follow-up, while another 7 (23.3%) responded to intracavernous injection. It is worth mentioning that tortuous and marked dilation of the deep dorsal vein and/or cavernous veins were found intraoperatively in 6 patients who were observed to have excellent erections postoperatively. Inadequate elimination of the leakage veins, especially crural veins, is the most likely factor in those who had a recurrence of erectile dysfunction. However, the corpus cavernosum, particularly a myopathic condition or inadequate neurotransmitters, also plays an important role. Complications included shortness of penis (3 patients), penile deviation (3), numbness of glans penis (4) and wound infection (1).(ABSTRACT TRUNCATED AT 250 WORDS)

The development of pericardial villi in the chick embryo.

The development of pericardial villi and their relation to the development of the cardiac surface was studied in chick embryos from the 3rd to 10th day of incubation by scanning electron microscopy. During the 3rd day of incubation (stage 14-17 HH) the coelomic epithelium covering the ventral wall of the sinus venosus forms villous protrusions. By the end of the 3rd day (stage 17 HH) these protrusions contact the dorsal wall of the heart, so that a secondary dorsal mesocardium is formed. This bridges the pericardial cavity between the ventral wall of the sinus venosus and the dorsal base of the ventricles. This sinu-ventricular mesocardium exists only temporarily, as on the 8th day of incubation it becomes a part of the cardiac wall due to fusion with the epicardium of the coronary sulcus. During the 4th and 5th day of incubation (stage 17-25 HH), the formation of the epicardium proceeds from the point of attachment of the sinu-ventricular mesocardium. Although these findings suggest that the epithelium of the villous protrusions spreads over the surface of the embryonic heart, one cannot exclude other hypotheses on epicardial origin. The impression of a spreading epicardium could also be created if epicardial cells were to delaminate from a local epithelium in a temporally and spatially organized pattern.

The great cardiac vein.

The great cardiac vein is the longest venous vessel of the heart; in the majority of our cases it originated at the lower third of the anterior interventricular sulcus (58%). The great and the middle cardiac veins merge at the apex of the heart, forming together with the coronary sinus into which they both empty, a complete venous ring around the left ventricle (13%). On reaching the area of the coronary sulcus, the great cardiac vein crosses the anterior interventricular branch and the circumflex branch of the left coronary artery forming the triangle of Brocq and Mouchet in which the vein is mainly superficial (61%). One, two or three anterior ventricular branches of the left coronary artery traverse this triangle; the relations of the vein and these arteries are very variable and practically unpredictable in 30% of the cases.

Myocardial coverage of the coronary sinus and related veins

AbstractThe incidence and distribution of landmarks relating to the coronary sinus (c.s.) were evaluated in 240 human hearts. Special attention was directed to the myocardial coat of the c.s., the distribution and pattern of the cardiac veins, and their dimensions. In all specimens the myocardial coat of the c.s. also covered the adjacent 2 to 11 mm of the great cardiac vein. In 15% of cases this myocardial layer was thickened in a sphincter‐like fashion, the edge of which was formed obliquely, in a crescent‐like manner, or diffusely without a sharp border.In 3% of the hearts the myocardial cover of the c.s. extended over the terminal 10 mm of the middle cardiac vein as a strong fiber cord. In 9%, single isolated belts of fibers fixated the terminal parts of the adjoining cardiac veins to the posterior wall of the left atrium, and in 8% two or three myocardial cords, embedded in the fatty tissue of the left coronary sulcus, did the same.Because the myocardial cover extended leftwards to variable distances over the c.s., the left edge of the myocardial covering cannot serve to define the beginning of the coronary sinus. The location of the ostial valve of the great cardiac vein (valve of Vieussens) was variable as well, being found on the average 2.5 mm proximal to the opening of the oblique vein of the left atrium. Moreover, the valve of the great cardiac vein was found in only 87% of cases; therefore it is inappropriate for defining the beginning of the coronary sinus. Finally, the dot‐like ostium of the oblique vein was most constant, and from the viewpoint of embryologic development, it is the logical landmark for determining the beginning of the coronary sinus, a necessary presupposition for cardiologic procedures like reperfusion of cardiac veins.

Anatomy of the tricuspid annulus. Circumferential myofibers as the structural basis for atrial flutter in a canine model.

Little anatomic information is available on the annular myocardium. This study was conducted to determine the anatomic substrate for atrial flutter due to circus movement around the tricuspid annulus in the Y-shaped incision canine model of atrial flutter. We studied photographs of the annular myocardium serial histological sections, made in either of three different planes, and compared these with photographs of the intact and blocked gross heart specimens. We found that the annulus is the most caudal region of the atrial wall. The epicardial aspect of the annulus abuts the ventricular septum or the aortic root in the medial region; in other regions, it is covered by the fat of the coronary sulcus. Its endocardial aspect is delimited by the tricuspid leaflets inferiorly and by the pectinate muscle bundles superiorly, except in the medial region where the pectinate muscle bundles are absent. The annular myocardium is bilaminated. A continuous subepicardial circumferential lamina is the most prominent and is robust in the anterior, lateral, and posterior regions, but it attenuates to a fine muscular connection in the medial region. Myofibers of its superior border merge with the pectinate muscle bundles or are admixed in the medial region with myocardium at the base of the medial atrial wall. Its inferior border makes little contact with the annulus fibrosus about the ring; however, in the medial region, these myofibers insert into fibrous tissue superior to the septal leaflet. A discontinuous, subendocardial perpendicular lamina contains myofibers that descend from the atrium; most of these myofibers insert into the annulus fibrosus about the ring, but the lamina is absent in the anteromedial region. We conclude that the continuous circumferential lamina provides the anatomic substrate for circus movement of excitation in this model.

Left Cranial Vena Cava in a Horse

A complete left cranial vena cava (LCVC) was found in a normal horse. The LCVC was well developed, but there was a complete absence of the right cranial vena cava. The azygous vein was normally distributed on the right side of the thoracic vertebral bodies but passed ventral to the aortic arch to empty into the cranial vena cava on the left close to the origin of the aortic arch. The LCVC passed over the dorsal aspect of the left atrium to reach the coronary sulcus on the caudal aspect of the heart. The LCVC opened into the right atrium via a 5 cm diameter orifice (orifice of coronary sinus). The vena cordis magna joined the LCVC 6 cm from the orifice of the coronary sinus. Complete dissection of the horse revealed no other developmental abnormalities. This case is compared with similar cases in the literature.

Atrioventricular and Ventriculoatrial Branches of the Coronary Arteries in Human Hearts

Atrioventricular (AV) and ventriculoatrial (VA) branches of the coronary arteries are vessels which supply simultaneously atrial and ventricular walls by means of recurrent rami. The terminology indicates the name of the main vessel followed by the name of the recurrent vessel both combined in an adjective. These branches establish a vascular 'suture' across the coronary sulcus in front (superficially to) or behind (deeply to) the trunks of the right coronary artery and of the left coronary artery (circumflex artery). The AV and VA branches, found in 95% of 40 human hearts, should be considered a normal characteristic of the coronary circulation and an important anatomical factor for the clinical interpretation of pathological cardiac phenomena.

陰茎硬度・周径連続測定法による本邦正常成人の夜間陰茎勃起現象の解析

Continuous monitoring of penile rigidity and tumescence has been proved to be of use for accurate diagnosis of erectile impotence, since it provides objective recording of penile rigidity as well as circumferential expansion. Prior to clinical use of this procedure in Japan, a study was performed to clarify normal features of nocturnal penile tumescence of Japanese and to ensure safety of this procedure. The subjects consisted of 16 normal volunteers, aged from 24 to 44 years. With fully informed consent of the volunteers, nocturnal penile rigidity and circumferential expansion were simultaneously measured for three consecutive nights by means of RigiScan at the base of the penis (base) and at about five millimeters proximal to the coronary sulcus (tip). The minimum circumference of the penis was 62.7 +/- 4.6 mm (mean +/- SD) at the tip and 65.4 +/- 9.3 mm at the base. The maximum circumference, which meant full erection in the normal volunteers, was 102.5 +/- 14.2 mm at the tip and 108.6 +/- 14.7 mm at the base. The mean duration of tumescence, i.e. circumference expansion more than 10 mm, was 23.0 +/- 6.9 minutes at the tip and 38.3 +/- 12.0 minutes at the base. The mean rate of episodes of circumference expansion more than 10 mm was 0.75 +/- 0.27 per hour at the tip and 0.70 +/- 0.26 per hour at the base. The maximum rigidity lasting more than 10 minutes was 82.9 +/- 10.1% at the tip and 85.4 +/- 8.4% at the base.(ABSTRACT TRUNCATED AT 250 WORDS)

Arterial Supply of the Region of the Coronary Sinus in Man

Patterns of arterial supply to the atria were studied with respect to the coronary sinus region in 60 human hearts obtained from patients with a negative cardiac history and in 2 hearts with ECG-demonstrated coronary sinus rhythm. The atria, including the interatrial septum, were supplied by the right (40%) or left (30%) or both (30%) sinuatrial arteries which, however, did not reach as far as the posterior margin of the oval fossa and the coronary sinus. The region of the coronary sinus with the Eustachian ridge received direct branches from the trunk of the right (41%) or left (11%) coronary artery or both (48%) in the adjacent part of the coronary sulcus. Possible development of the 'coronary sinus rhythm' on the basis of multifocal damage of the sinuatrial arteries is discussed.

Two cases of double superior vena cava.

Two cases of double superior vena cava were found among 300 Japanese cadavers dissected at Kyoto University from 1980 to 1989. Case 1 was an 82-year-old male patient who died of cerebral infarction. Case 2 was a 39-year-old well-developed male patient who died of sepsis. They had no history of cardiovascular disorders. Common features in both cases are as follows: In addition to a right superior vena cava with normal appearance located in the normal position, on the left side, a normal-looking extra superior vena cava persisted and descended vertically in front of the aortic arch between the left pulmonary vein and the left auricle, traversed the coronary sulcus and finally drained into the right atrium. No differences in diameter were found between right and left venae cavae. No communicating vessels were present between them. Therefore, both cases, which had a persistent left superior vena cava draining into the coronary sinus, may be classified as McCotter's 1st type (1916) or Donadio's 3rd type (1925). Furthermore, in Case 2, the double azygos vein persisted symmetrically, suggesting the 4th type of Nandy and Blair (1965). In addition to venous anomalies, Case 2 had arterial anomalies such as the right subclavian artery arising as the last branch of the aortic arch similar to the G type of Adachi (1928), and the right vertebral artery arising from the right common carotid artery. The present cases are considered to be the 53rd and 54th cases of double superior vena cava found in Japanese cadavers, and the 18th and 19th cases of double superior vena cava without communicating vessels between them.