Transcatheter aortic valve implantation and hybrid coronary artery revascularization: time to combine them

We report on simultaneous off-pump coronary artery bypass grafting to the left anterior descending artery, modified transapical aortic valve implantation, and stenting of the circumflex and right coronary arteries in an 84-year-old patient. The poly-morbid patient with a logistic EuroSCORE of 85% experienced recent myocardial infarction; the left ventricular ejection fraction was reduced to 20%. Postoperative recovery was fast and short. The strategy described is the next logical step in broadening the indication for transcatheter aortic valve interventions.     

Earlier accumulation of calcium, phosphorus, and magnesium in the coronary artery in comparison with the ascending aorta, aortic valve, and mitral valve

To explore reasons for a high accumulation of Ca and P occurring in the coronary artery of Thai with aging, the authors investigated age-related changes of elements in the coronary artery, ascending aorta near the heart, and cardiac valves in single individuals, and the relationships in the elements between the coronary artery and either the ascending aorta or cardiac valves. After an ordinary dissection by medical students at Chiang Mai University was finished, the anterior descending arteries of the left coronary artery, ascending aortas, mitral valves, and aortic valves were resected from the subjects. The subjects consisted of 17 men and 9 women, ranging in age from 46 to 76 yr. The element content was analyzed by inductively coupled plasma-atomic emission spectrometry. The average content of Ca and P was the highest in the coronary artery and decreased in the order aortic valve, ascending aorta, and mitral valve. The Ca, P, and Mg content increased in the coronary artery in the fifties and in the ascending aorta, aortic valve, and mitral valve in the sixties. It should be noted that the accumulation of Ca, P, and Mg occurred earlier in the coronary artery than in the ascending aorta, aortic valve, and mitral valve. It was found that with respect to the Ca, P, Mg, and Na contents, the coronary artery correlated well with both the aortic valve and ascending aorta, especially with the aortic valve, but it did not correlate with the mitral valves. This finding suggests that the accumulation of Ca, P, Mg, and Na occurs in the coronary artery together with the aortic valve and ascending aorta, but not together with the mitral valve. Because regarding the accumulation of Ca, P, and Mg, the ascending aorta and aortic valve are preceded by the coronary artery, it is unlikely that the accumulation of Ca, P, and Mg spreads from the ascending aorta or aortic valve to the coronary artery.     

Biomechanical signals in the coronary artery triggering the metabolic processes during cardiac overload

Peculiarities in structure and deformability of epicardial conduit coronary arteries are described. The thin wall of animal coronary artery contrasts the human coronary artery in which the remarkable wall thickness is due namely by the intima thickness. Deformation in length and diameter of conduit coronary arteries, due to the left and right ventricle volume increase, has been defined in non-beating canine heart. Ramus interventricularis anterior being firmly tethered to the myocardium undergoes about 3 times larger deformation than ramus circumflexus In anaesthetized dogs a 30% increase in blood pressure, elicited by aortic constriction, induces an increase in diameter of coronary artery, in segment lenght, in blood flow and consequently in shear stress which represents a load for circumferentially running smooth muscle bundles, longitudinally running smooth muscle bundles, as well as for the endothelium. The above load lasting 4 h is already reflected by an increase in total RNA content and [¹⁴C] leucin incorporation in the left ventricle myocardium in the wall of ramus interventricularis anterior, not in ramus circumflexus. The finding fit completely with the different range of deformation of both the above coronary branches and indicates an increase in proteosynthesis not only in myocardium, but in ramus interventricularis anterior as well. An increase in ornithindecarboxylase activity in coronary wall leading to an increase in biogenic polyamines, is present in the case only, when blood pressure increase is induced by infusion of noradrenaline.     

金钱豹和猪獾冠状动脉的解剖

为了阐明金钱豹(Panthera pardus)和猪獾(Arctonyx collaris)心冠状动脉的分支分布特征及血供情况,为心脏生物学及动物学研究提供结构基础资料,利用血管铸型和组织透明方法观察研究了金钱豹与猪獾心左、右冠状动脉的分支分布.结果表明,金钱豹和猪獾的心均由左右冠状动脉营养.金钱豹左冠状动脉分为室间隔支、前降支和旋支.前降支又分出左室上支、左室中支和左室下支.右冠状动脉沿途分出右室前支、右室后下支和右室后上支.猪獾左冠状动脉分为前降支和旋支.前降支又分出室间隔支和左室前支,旋支又分出左缘支和左室后支.其右冠状动脉沿途分出右室前支、右缘支和右室后支.金钱豹和猪獾心的室间隔均由发自左冠状动脉的独立的室间隔支营养,二者左右冠状动脉在膈壁的分布属于均衡型.     

Arterial supply of the atrio-ventricular bundle and its right branch by the first diagonal artery: a dual vascularization

A case is described in which a septal artery originating from the first artery contributed to the vascular supply of the atrio-ventricular bundle, its right branch, the moderator band and the anterior papillary muscle of the right ventricle. Postmortem coronary angiograms and microdissection were use to determine the course of the arteries. The different patterns of origin of the anterior septal arteries were reviewed, and the role of these arteries as an anastomotic route in situations of proximal stenosis of the anterior interventricular artery is discussed.     

The arterial system of the sperm whale (Physeter macrocephalus)

The angioarchitecture of the sperm whale is basically similar to that of other mammals, but it has specific attributes associated with the aquatic environment of this animal and its tolerance for deep and long diving. Specialized features include an expansive aortic arch, unusually far anterior localization of the arch, symmetrical branching of common carotid and subclavian arteries from the aorta, the absence of direct connection between internal carotid arteries and brain arteries, the absence of a costocervical artery, and the presence of a well-developed occipital artery. The sperm whale has extraordinarily well-developed retia mirabilia, distributed in the cranial cavity, vertebral canal, neck and thoracic cavity, around the optic nerve, and in the walls of the uterus. These retia are more extensively developed in the sperm whale than in any other cetacean previously studied. J. Morphol. 234:37–50, 1997. © 1997 Wiley-Liss, Inc.     

Differential effects of serotonergic and peptidergic cardioexcitatory neurons on the heart activity in the pteropod mollusc, Clione limacina

A group of four cardioexcitatory neurons has been identified in the intestinal ganglia of the mollusc Clione limacina. Relatively weak stimulation of the intestinal neurons induced auricle contractions only, while strong stimulation produced initial auricle contractions followed by full-cycle auricle-ventricle contractions. Intestinal cardioexcitatory neurons probably utilized as their transmitter a peptide similar to Tritonia pedal peptide – they showed pedal peptide-like immunoreactivity, and their effects were mimicked by application of the exogenous pedal peptide. The pedal cardioexcitatory neuron was found to produce strong excitatory effects only on the ventricle contractions. Its stimulation induced ventricle contractions in the quiescent heart or significantly accelerated the rate of ventricle contractions in the rhythmically active heart. The pedal cardioexcitatory neuron apparently utilized serotonin as a neurotransmitter, based upon serotonin immunoreactivity, blocking effect of serotonin antagonists mianserin and methysergide, and the observation that exogenous serotonin mimicked its effect. A dense network of pedal peptide-like immunoreactivity was found both in the auricle and ventricle tissue. Serotonin immunoreactivity was densely present in the ventricle, while the auricle contained only a separate serotonin-immunoreactive unbranched axon. Thus, there are two separate groups of central cardioexcitatory neurons with different effects on heart activity, which together might provide a complex cardio-regulatory function in Clione. Accepted: 14 August 1999     

Use of pattern recognition to classify beef cardiovascular tissues on the basis of their trace metal compositions.

The pattern recognition procedure of discriminant analysis has been used to characterize the trace metal profiles created by the concentrations of 8 trace metals in 15 anatomic sites of beef heart tissue. Metals analyzed were copper, tin, lead, molybdenum, strontium, cesium, barium, and aluminum. Anatomic sites sampled included main pulmonary artery, aorta, mitral and tricuspid valves, left and right coronary arteries, os cordis, right atrium, left atrial appendage, crista supraventricularis, left bundle branch, free wall of the right and left ventricles, interventricular septum, and papillary muscle of the left ventricle. The striking features of the data were: (1) All specimens of the mitral valve, tricuspid valve, and os cordis were ambiguously described by their trace metal profiles; (2) the four blood vessels constituted two groups of two tissues each (aorta, main pulmonary artery; left and right coronary arteries); (3) tissues derived from ordinary and specialized myocardium were quite different from blood vessels, heart valves and os cordis. Using these profiles, 85% of the specimens analyzed were correctly classified by discriminant analysis with respect to their anatomic origin.     

Quantification of eNOS mRNA in the canine cardiac vasculature by competitive PCR

The goal of the present study was to develop a competitive PCR assay to measure changes in the expression of endothelial nitric oxide synthase (eNOS) mRNA levels throughout the canine vascular tree. A partial sequence of canine eNOS cDNA (1.86 kb), inducible NOS (1.95 kb), and neuronal NOS (1.16 kb) was cultured from canine aortic endothelial cells, LPS-treated canine splenic vein endothelial cells, and from canine left ventricle, respectively. Competitor eNOS cDNA (eNOS-C) was constructed via recombinant PCR. Thus, with the use of a standard curve competitive PCR with eNOS-C, the amount of eNOS mRNA in 500 ng of total RNA was greatest in the circumflex > right coronary artery > left anterior descending coronary artery > aorta. The isolation of coronary microvessels from the left ventricle was associated with an enrichment of endothelial cell markers such as eNOS, von Willebrand factor, and caveolin-1, an observation supported by the detection of up to 15-fold higher levels of eNOS mRNA in coronary microvessels relative to the larger arteries. The ability to quantify changes in eNOS mRNA levels throughout the canine vasculature should provide greater insight into the molecular mechanisms of how this gene is regulated in physiological and pathophysiological states.     

Uncommon acquired Gerbode defect following extensive bicuspid aortic valve endocarditis

Gerbode defect is a rare type of left ventricle to right atrium shunt. It is usually congenital in origin, but acquired cases are also described, mainly following infective endocarditis, valve replacement, trauma or acute myocardial infarction. We report a case of a 50-year-old man who suffered an extensive and complex infective endocarditis involving a bicuspid aortic valve, the mitral-aortic intervalvular fibrosa and the anterior leaflet of the mitral valve. After dual valve replacement and annular reconstruction, a shunt between the left ventricle and the right atrium - Gerbode defect, and a severe leak of the mitral prosthesis were detected. Reintervention was performed with successful shunt closure with an autologous pericardial patch and paravalvular leak correction. No major complications occurred denying the immediate post-surgery period and the follow-up at the first year was uneventful.     

Accumulation of elements in the arteries and cardiac valves of Thai with aging

To elucidate whether the extent of element accumulation in the arteries and cardiac valves with aging was different between different races, the authors investigated the accumulation of elements in the arteries and cardiac valves of the Thai with aging and the relationships among elements in the cardiac valves. After ordinary dissection at Chiang Mai University was finished, 16 arteries and 4 cardiac valves were resected and element contents were determined by inductively coupled plasma-atomic emission spectrometry. In the 16 arteries, the average content of calcium was the highest in the site of the abdominal aorta ramifying into the common iliac arteries, and it decreased in the order internal iliac, coronary, abdominal aorta, common iliac, external iliac, superior mesenteric, inferior mesenteric, thoracic aorta, brachial, radial, common carotid, subclavian, ulnar, axillary, renal, and internal thoracic arteries. The average contents of phosphorus and magnesium in respective arteries were parallel with the average contents of calcium, except for the coronary artery. In comparison with the arteries of the Japanese, the trend of calcium accumulation in the arteries of the Thai was almost similar to that in the arteries of the Japanese, except for the coronary artery and thoracic aorta. The calcium accumulation in the coronary artery was much higher in the Thai than in the Japanese, whereas that in the thoracic aorta was lower in the Thai than in the Japanese. Regarding elements in the cardiac valves, the calcium content increased remarkably in the seventies in the aortic valve and in the nineties in the pulmonary valve, but it hardly increased in both the mitral and tricuspid valves with aging. The average content of calcium was the highest in the aortic valve, and it decreased in the order pulmonary, tricuspid, and mitral valves. Regarding the relationship among elements in the aortic valves, it was found that there were extremely significant direct correlations among the contents of calcium, phosphorus, and magnesium, whereas there were significant direct correlations between zinc and either calcium or phosphorus contents. Although significant correlations were found between sulfur and the other element contents in the aortic valves of the Japanese, no significant correlations were found between them in the aortic valves of the Thai. In the mitral valves, extremely or very significant direct correlations were found among the contents of calcium, phosphorus, magnesium, and sulfur, with some exceptions that there were no significant correlations between phosphorus and either magnesium or sulfur contents. In addition, no significant correlation was found in the calcium content between the aortic valve and coronary artery in the same individuals.     

Mitral valve prolapse detected during hemodynamic studies

To estimate frequency of the posterior mitral valve leaflet prolapse in routinely performed left ventriculography, 1000 consecutive ventriculograms of the right anterior oblique projection were analyzed. A group of patients consisted of 511 women and 489 men at mean age 46,5 years. Clinical diagnosis of heart lesions, myocardial disease, pulmonary hypertension or arrhythmias were indications for hemodynamic studies. In the investigated group of patients, there were no patients with clinical diagnosis of the coronary artery disease. Prolapse of the posterior mitral valve leaflet was diagnosed in 59 patients. Idiopathic mitral valve prolapse was diagnosed in 10 patients. Prolapse of the posterior mitral valve leaflet was most frequent in atrial septal defect (16.6%), myocardial lesion (12.5%), and after mitral commissurotomy (8.9%). Posterior mitral valve leaflet prolapse is not a frequent anomaly in routinely performed left ventriculography. Relatively often occurrence of the mitral valve prolapse in atrial septal defect and only occasional in the aortic lesions and dilated cardiomyopathy seems to point out at a role of the left ventricle size in pathogenesis of this syndrome.     

INSERTION OF AN INTRAAORTIC BALLOON THROUGH A LIMB OF AN AORTOFEMORAL GRAFT AFTER AORTIC VALVE REPLACEMENT, DOUBLE CORONARY ARTERY BYPASS, AND RESECTION OF AN ABDOMINAL AORTIC ANEURYSM

This case report describes a useful and unusual route for insertion of an intraaortic balloon in 63-year-old man who was operated upon for calcific aortic stenosis, coronary atherosclerosis involving the left anterior descending and right coronary arteries, and a large abdominal aortic aneurysm. Aortic valve replacement was accomplished with a porcine heterograft prosthesis. Bypasses to the left anterior descending and right coronary arteries were constructed with reversed saphenous vein grafts, and the abdominal aneurysm was resected and repaired with a bifurcated woven Dacron vascular graft. An electively placed intraaortic balloon was inserted through the right limb of the aortic graft prosthesis and used to assist the patient during the immediate postoperative period. Uneventful recovery ensued.     

Coronary artery embryogenesis in cardiac defects induced by retinoic acid in mice

BACKGROUND: Although normal coronary artery embryogenesis is well described in the literature, little is known about the development of coronary vessels in abnormal hearts. METHODS: We used an animal model of retinoic acid (RA)-evoked outflow tract malformations (e.g., double outlet right ventricle [DORV], transposition of the great arteries [TGA], and common truncus arteriosus [CTA]) to study the embryogenesis of coronary arteries using endothelial cell markers (anti-PECAM-1 antibodies and Griffonia simplicifolia I (GSI) lectin). These markers were applied to serial sections of staged mouse hearts to demonstrate the location of coronary artery primordia. RESULTS: In malformations with a dextropositioned aorta, the shape of the peritruncal plexus, from which the coronary arteries develop, differed from that of control hearts. This difference in the shape of the early capillary plexus in the control and RA-treated hearts depends on the position of the aorta relative to the pulmonary trunk. In both normal and RA-treated hearts, there are several capillary penetrations to each aortic sinus facing the pulmonary trunk, but eventually only 1 coronary artery establishes patency with 1 aortic sinus. CONCLUSIONS: The abnormal location of the vessel primordia induces defective courses of coronary arteries; creates fistulas, a single coronary artery, and dilated vessel lumens; and leaves certain areas of the heart devoid of coronary artery branches. RA-evoked heart malformations may be a useful model for elucidating abnormal patterns of coronary artery development and may shed some light on the angiogenesis of coronary artery formation.     

Numerical Modeling of Intraventricular Flow during Diastole after Implantation of BMHV

This work presents a numerical simulation of intraventricular flow after the implantation of a bileaflet mechanical heart valve at the mitral position. The left ventricle was simplified conceptually as a truncated prolate spheroid and its motion was prescribed based on that of a healthy subject. The rigid leaflet rotation was driven by the transmitral flow and hence the leaflet dynamics were solved using fluid-structure interaction approach. The simulation results showed that the bileaflet mechanical heart valve at the mitral position behaved similarly to that at the aortic position. Sudden area expansion near the aortic root initiated a clockwise anterior vortex, and the continuous injection of flow through the orifice resulted in further growth of the anterior vortex during diastole, which dominated the intraventricular flow. This flow feature is beneficial to preserving the flow momentum and redirecting the blood flow towards the aortic valve. To the best of our knowledge, this is the first attempt to numerically model intraventricular flow with the mechanical heart valve incorporated at the mitral position using a fluid-structure interaction approach. This study facilitates future patient-specific studies.     

Coronary artery anomalies and aortic valve morphology in the Syrian hamster

In the Syrian hamster, anomalies in the origin of the left coronary artery are significantly associated with the bicuspid condition of the aortic valve. In this species, bicuspid aortic valves are expressions of a trait, the variation of which takes the form of a phenotypic continuum, ranging from a tricuspid aortic valve with no commissural fusion to a bicuspid aortic valve with the aortic sinuses located in ventrodorsal orientation and devoid of any raphe. The intermediate stages of the continuum are represented by tricuspid aortic valves with a more or less extensive fusion of the ventral commissure and bicuspid aortic valves with a more or less developed raphe located in the ventral aortic sinus. The present study was designed to decide whether there is a gap between tricuspid and bicuspid aortic valves regarding the incidence of coronary artery anomalies, or whether this incidence varies according to the different tricuspid and bicuspid morphotypes of the continuum. The study was carried out in Syrian hamsters belonging to a single inbred family with a high incidence of tricuspid aortic valves with fusion of the ventral commissure, bicuspid aortic valves, and anomalies in the origin of the left coronary artery, i.e. single right coronary artery ostium in aorta, anomalous origin of the left coronary artery from the pulmonary artery, and anomalous origin of the left coronary artery from the dorsal aortic sinus. The specimens were examined by means of a stereomicroscope and, in several cases, scanning electron microscopy was also used. The relationships between anomalous coronary artery patterns and aortic valve morphologies were tested using a logistic regression model. The results obtained indicate that there is no discontinuity between tricuspid and bicuspid aortic valves regarding the incidence of coronary artery anomalies. The probability of occurrence of anomalous coronary artery patterns increases continuously according to the deviation degree of the aortic valve from its normal (tricuspid) design. The present findings suggest that in the Syrian hamster, the morphogenetic mechanisms involved in the formation of congenital anomalous aortic valves and anomalies in the origin of the left coronary artery, respectively, are strongly related from an aetiological viewpoint.     

Factors affecting the heart activity and blood pressure of the swan mussel Anodonta cygnea.

1. The rate of heart beat increased with temperature and was three times as high in the active as in the inactive animal. 2. The rate of shell valve movement rose and the rate of heart beat fell when the foot was extended. 3. The rates of heart beat and shell valve movement decreased when the water was saturated with carbon dioxide. This heart response remained when the visceral ganglion was destroyed. 4. Ventricular contraction occurred simultaneously over the shole chamber. The passage of blood into the posterior aorta could be restricted by the protuberances on its wall. 5. Pericardial cavity pressure rose by about 5 cm H2O at shell valve adduction and 0-25--0-6 cm H2O at ventricular diastole. 6. Pulse pressure changes of 0-25--0-6 cm H2O occurred in the auricle and 1--3 cm H2O in the ventricle and anterior aorta.     

Right Internal Mammary Artery Implantation into Right Ventricular Myocardium for Revascularization of the Entire Heart: Experimental Data and Preliminary Report

The left internal mammary artery implant combined with epicardiectomy and free omental graft provides three extra-coronary sources of blood. This operation tested in dogs with 92% main-stem occlusion of three coronary arteries protected 75% of the animals. Applied clinically in over 100 patients, the operation resulted in 90% improvement. To obtain complete myocardial revascularization, the right internal mammary artery has been used as a fourth source of extra-coronary blood. In 57 animals, the right internal mammary arteries were implanted into the anterior walls of the right ventricle; in 80% this vessel formed anastomoses with the right coronary tree, and in 65% with the right and left coronary arteriolar systems. Six patients are described who underwent right internal mammary artery implantation; five of these in addition had the combined operation of left internal mammary artery implant, epicardiectomy and free omental graft. All patients had completely blocked right coronary arteries; in addition, five had advanced disease of the left coronary arterial tree.     

Modelling the circle of Willis to assess the effects of anatomical variations and occlusions on cerebral flows

Blood flow in the circle of Willis (CoW) is modelled using the 1-D equations of pressure and flow wave propagation in compliant vessels. The model starts at the left ventricle and includes the largest arteries that supply the CoW. Based on published physiological data, it is able to capture the main features of pulse wave propagation along the aorta, at the brachiocephalic bifurcation and throughout the cerebral arteries. The collateral ability of the complete CoW and its most frequent anatomical variations is studied in normal conditions and after occlusion of a carotid or vertebral artery (VA). Our results suggest that the system does not require collateral pathways through the communicating arteries to adequately perfuse the brain of normal subjects. The communicating arteries become important in cases of missing or occluded vessels, the anterior communicating artery (ACoA) being a more critical collateral pathway than the posterior communicating arteries (PCoAs) if an internal carotid artery (ICA) is occluded. Occlusions of the VAs proved to be far less critical than occlusions of the ICAs. The worst scenario in terms of reduction in the mean cerebral outflows is a CoW without the first segment of an anterior cerebral artery combined with an occlusion of the contralateral ICA. Furthermore, in patients without any severe occlusion of a carotid or VA, the direction of flow measured at the communicating arteries corresponds to the side of the CoW with an absent or occluded artery. Finally, we study the effect of partial occlusions of the communicating arteries on the cerebral flows, which again confirms that the ACoA is a more important collateral pathway than the PCoAs if an ICA is occluded.     

A radiological study of the central circulation in the lungfish, Protopterus aethiopicus

The dipnoan heart is only in part structurally developed to support a separated circulation in pulmonary and systemic circuits. In the present investigation biplane angiocardiography has been used to describe the extent of such a double circulation and the factors which may modify it in the African lungfish, Protopterus aethiopicus. Contrast injections in the pulmonary vein revealed a clear tendency for aerated blood returing from the lungs to be selectively dispatched to the anterior branchial arteries giving rise to the major systemic circulation. Contrast injections in the vena cava delineated the sinus venosus as a large receiving chamber for systemic venous blood. Contraction of the sinus venosus discharged blood into the right, posterior part of the partially divided atrial space. Contrast injection in the pulmonary vein showed that vessel to pass obliquely from right to left such that blood was emptied distinctly into the left side of the atrium. During contraction the atrial space tended to retain a residual volume in its anterior undivided part which minized mixing. Ventricular filling occurred through separate right and left atrio-ventricular connections. Right-left separation in most of the ventricle was maintained by the partial ventricular septum, the trabeculated, spongelike myocardium and the mode of inflow from the atria. Mixing in the anterior undivided portion of the ventricle during the ejection phase was slight due to a streamlined ejection pattern. The outflow through the bulbus cordis occurred in discrete streams which in part were structurally separated by well developed spiral folds. In the anterior bulbus segment the spiral folds are fused and make completely separate dorsal and ventral outflow tracts. The ventral bulbus channel provides blood to the three anterior branchial arteries. The second and third branchial arteries are large and represent direct shunts to the dorsal aorta. The fourth and fifth branchial arteries are gill bearing and receive blood form the dorsal bulbus channel. The most posterior epibranchial vessels give rise to the pulmonary arteries.