Congenital coronary artery-cardiac chamber fistulae: Report of two cases

Two cases of coronary arteriovenous fistulae are reported. In the first case, the right coronary artery (RCA) drained into the right ventricular outflow tract, and the distal RCA filled through a branch of the left anterior descending coronary artery. In the second case, the RCA drained into the right atrium and filled through a branch of the left circumflex artery. The fistulae were closed with subcoronary mattress sutures that preserved the continuity of the native circulation.     

A rare combination of coronary anomalies

Coronary anomalies are found in less than 1% of diagnostic coronary angiograms. The clinical relevance of these anomalies varies from insignificant to potentially lethal. The major role of coronary angiography in interventional cardiology and coronary surgery underscores the importance of having knowledge of the variations in coronary anatomy and their clinical relevance. We report a rare case of a patient with a combination of coronary anomalies: coronary fistulae, a double circumflex coronary artery and anomalous origin of a circumflex artery from the proximal right coronary artery. (Neth Heart J 2009;17:387-9.)     

Recurrent electromechanical dissociation due to severe underlying coronary heart disease.

Recurrent electromechanical dissociation, eventually fatal, presented as Stokes-Adams-like syncope in a patient with severe underlying coronary heart disease. Mechanical function was probably suppressed because of myocardial ischemia due to recent occlusion of the proximal right main coronary artery; the left main coronary artery had been occluded previously. Spasm of the proximal right coronary artery may have accounted for his recurrent attacks of pain and syncope. It is suggested that this clinical picture has a grave prognosis, demanding urgent therapeutic measures. While these measures are likely to be more hazardous than usual, the grave prognosis and potential for therapeutic success make them well worth the risk.     

Scanning electron microscopy substantiates histology in showing the inadequacy of the existing theories on the development of the proximal coronary arteries and their connections with the arterial trunks

Development of proximal coronary arterial segments and coronary arterial orifices was studied by scanning electron microscopy in 20 rat embryos and by light microscopy in serial sections of 20 human and another 18 rat embryos. Neither by scanning electron microscopy nor by light microscopy did we observe more than two coronary arterial orifices. These coronary orifices were always situated in the sinuses of the aorta that faced the pulmonary artery. In the human embryos the coronary orifices emerged between 37-39 days of gestation (16-19 mm crown-rump length, Streeter horizon XVIII-XIX) and were invariably present beyond 39 days (19 mm crown-rump length, Streeter horizon XIX). In rat embryos, the coronary orifices emerged in both scanning electron microscopy and light microscopy at 15-17 days of gestation (13-17 mm crown-rump length) and were invariably present beyond 17 days (17 mm crown-rump length). In both human and rat embryos, either by scanning electron microscopy and light microscopy, the left coronary orifice was observed significantly earlier. In all the investigated embryos, human as well as rat, septation at arterial orifice level was complete, including the earliest stages studied. Light microscopy showed that at the emerging stages of the coronary orifices, the proximal epicardial segments of the left and right coronary arteries could already be identified in a peritruncal ring of epicardial vasculature, before the coronary orifice was observed. This was the case in human as well as in rat embryos. Thus, a coronary orifice was never seen in the absence of a proximal coronary artery. The present theories on development of the proximal coronary arteries and coronary orifices do not offer an adequate explanation for either these data or the known possible congenital abnormalities of the coronary arteries. Our study supports dual proximal coronary arterial development. These two proximal coronary arteries develop out of a peritruncal ring of vascular structures on to the aorta. The process by which the coronary orifices actually develop remains to be explained.     

Anomalous right coronary artery originating from the left sinus of Valsalva in a Yucatan minipig

A 39.2-kg, castrated male Yucatan minipig (Sus scrofa domestica) was presented for enrollment in a coronary artery study. Angiography revealed an anomalous right coronary artery originating from the left sinus of Valsalva. The left anterior descending, left circumflex, and anomalous right coronary arteries were implanted with metallic stents without complications. The minipig remained on the study for 3 mo until it reached its predetermined study endpoint, during which time it showed no clinical signs of disease. Histologic examination of the implanted coronary arteries revealed no differences between the normal (left anterior descending and left circumflex arteries) and the anomalous right coronary artery. Swine are important models for coronary research. Although several cases of anomalous human coronary arteries have been documented, the current case is the first report of a coronary artery anomaly in a minipig.     

Dynamic capacitance of epicardial coronary arteries in vivo

The dynamic capacitance of epicardial coronary arteries (i.d. greater than or equal to 0.4 mm) in vivo was assessed from the volume stiffness and volume of these arteries. The volume stiffness was derived from the pressure wave front velocity as determined in dogs by measuring the delay time between the pressure pulses recorded proximal and distal to a segment of the anterior descending branch of the left coronary artery. The pressure pulse was generated elsewhere in the arterial system during diastole. The volume of the epicardial coronary arteries was calculated from the lengths and diameters as measured in araldite casts, making corrections for in-vitro/in-vivo differences in dimensions. The dynamic capacitance of the right coronary artery, and the anterior descending and circumflex branches of the left coronary artery at an arterial pressure of 13.3 kPa and a frequency between 7 and 30 Hz was found to be 0.0024 +/- 0.0013, 0.0062 +/- 0.0028 and 0.0079 +/- 0.0035 mL/kPa (mean +/- SD), respectively. The total capacitance of the epicardial coronary arteries was calculated to be (0.007 mL/kPa)/100 g, which is small as compared to the total capacitance of the coronary vasculature, including the intramyocardial compartment, which is in the order of (0.5 mL/kPa)/100 g [1].     

Velocity and wall shear stress patterns in the human right coronary artery.

Blood flow dynamics in the human right coronary artery have not been adequately quantified despite the clinical significance of coronary atherosclerosis. In this study, a technique was developed to construct a rigid flow model from a cast of a human right coronary artery. A laser photochromic method was used to characterize the velocity and wall shear stress patterns. The flow conditions include steady flow at Reynolds numbers of 500 and 1000 as well as unsteady flow with Womersley parameter and peak Reynolds number of 1.82 and 750, respectively. Characterization of the three-dimensional geometry of the artery revealed that the largest spatial variation in curvature occurred within the almost branch-free proximal region, with the greatest curvature existing along the acute margin of the heart. In the proximal segment, high shear stresses were observed on the outer wall and lower, but not negative, stresses along the inner wall. Low shear stress on the inner wall may be related to the preferential localization of atherosclerosis in the proximal segment of the right coronary artery. However, it is possible that the large difference between the outer and inner wall shear stresses may also be involved.     

Redistribution in left ventricular regional flow following acute right ventricular pressure overload

The left ventricular dysfunction following acute pulmowary hypertension remains unexplained. We wondered if acute pulmonary hypertension could alter the transmural flow distribution within the left ventricular myocardium, independent of coronary flow and perfusion pressure. We used a canine preparation in which the left coronary system was perfused at constant flow and induced a two- to three-fold increase in pulmonary artery pressure by banding the pulmonary artery. Regional myocardial blood flow of the left coronary system was measured using radioactive microspheres, injected into the left coronary system before and after 10-30 min of banding of the pulmonary artery. The left ventricular subendocardial:epicardial ratio fell by 12 and 31% (p less than 0.05) of control value, 10 and 30 min, respectively, after banding of the pulmonary artery, the total flow to the left coronary system being kept constant. Left atrial mean pressure increased from 2.9 +/- 2.4 to 3.6 +/- 1.9 and 6.0 +/- 2.1 (p less than 0.05) following banding. The mechanism of the redistribution of coronary flow may relate to inappropriate vasodilation of the right septal myocardium with consequent relative left ventricular subendocardial hypoperfusion which might aggravate left ventricular ischemia in the presence of hypotension and hypoxia.     

Differences in cardiac microcirculatory wave patterns between the proximal left mainstem and proximal right coronary artery

Despite having almost identical origins and similar perfusion pressures, the flow-velocity waveforms in the left and right coronary arteries are strikingly different. We hypothesized that pressure differences originating from the distal (microcirculatory) bed would account for the differences in the flow-velocity waveform. We used wave intensity analysis to separate and quantify proximal- and distal-originating pressures to study the differences in velocity waveforms. In 20 subjects with unobstructed coronary arteries, sensor-tipped intra-arterial wires were used to measure simultaneous pressure and Doppler velocity in the proximal left main stem (LMS) and proximal right coronary artery (RCA). Proximal- and distal-originating waves were separated using wave intensity analysis, and differences in waves were examined in relation to structural and anatomic differences between the two arteries. Diastolic flow velocity was lower in the RCA than in the LMS (35.1 +/- 21.4 vs. 56.4 +/- 32.5 cm/s, P < 0.002), and, consequently, the diastolic-to-systolic ratio of peak flow velocity in the RCA was significantly less than in the LMS (1.00 +/- 0.32 vs. 1.79 +/- 0.48, P < 0.001). This was due to a lower distal-originating suction wave (8.2 +/- 6.6 x 10(3) vs. 16.0 +/- 12.2 x 10(3) W.m(-2).s(-1), P < 0.01). The suction wave in the LMS correlated positively with left ventricular pressure (r = 0.6, P < 0.01) and in the RCA with estimated right ventricular systolic pressure (r = 0.7, P = 0.05) but not with the respective diameter in these arteries. In contrast to the LMS, where coronary flow velocity was predominantly diastolic, in the proximal RCA coronary flow velocity was similar in systole and diastole. This difference was due to a smaller distal-originating suction wave in the RCA, which can be explained by differences in elastance and pressure generated between right and left ventricles.     

Anomalous origin of the left coronary artery from the pulmonary artery treated by palliative Vineberg operation in an infant

Anomalous origin of the left coronary artery from the pulmonary artery was diagnosed in an infant girl who had evidence of transmural myocardial infarction of the free wall of the left ventricle. At age 13 months, she underwent a palliative left Vineberg implant, and remained asymptomatic until she was 8 years of age. At that time, she underwent suturing of the left coronary ostium for obliteration of the left coronary shunt at the pulmonary artery. At age 13, she underwent aortocoronary bypass to the left main coronary artery, with end-to-end anastomosis. The patient remains asymptomatic to date. We believe that this is the first reported case of a Vineberg operation performed in an infant for palliation of an anomalous left coronary artery originating from the pulmonary artery. This method allows time for the development of collateral circulation to the left coronary artery before definitive surgery is performed.     

Kawasaki disease causing saccular aneurysms of the coronary arteries

A 22-year-old man was referred for treatment of a 45 mm saccular aneurysm of the right coronary artery (RCA) and a 15 mm saccular aneurysm of the left anterior descending artery (LAD). The patient developed Kawasaki disease in 1998. The aneurysms were diagnosed in 2002. The RCA showed thrombus formation. Until now the patient had remained asymptomatic. He now presented with effort angina. On coronary angiography and magnetic resonance imaging, an occluded aneurysm of the proximal RCA (45 mm) was seen with a second aneurysm more distally (22 mm).     

Robotically assisted coronary endarterectomy

Robotic assistance has enabled coronary artery bypass surgery to be performed safely in a completely endoscopic fashion, but diffusely diseased target vessels may pose a technical challenge. We present a case in which coronary endarterectomy was performed on the left anterior descending coronary artery during a two-vessel totally endoscopic coronary artery bypass procedure. A 52-year-old woman presented with intermittent substernal pain. Preoperative studies showed diffuse disease in the left coronary artery system. Bilateral internal mammary arteries were harvested robotically using a skeletonized technique in a completely endoscopic fashion. Cardiopulmonary bypass was achieved via peripheral cannulation, and the heart was arrested with intermittent cold antegrade hyperkalemic blood cardioplegia delivered via an ascending aortic occlusion balloon catheter. The first obtuse marginal anastomosis was performed. The left anterior descending coronary artery was diffusely diseased and heavily calcified. An end-to-side anastomosis was attempted to the right internal mammary artery with unsatisfactory results. A localized coronary endarterectomy was performed, and an extended anastomosis was completed using the right internal mammary artery. The patient recovered uneventfully and was discharged home on postoperative day 6. Diffuse coronary artery disease was once thought to be a prohibitive challenge for minimally invasive coronary bypass procedures. This case demonstrates that local coronary endarterectomy is feasible and safe in robotic totally endoscopic coronary artery bypass surgery.     

Anomalous origin of the left coronary artery: the effects of aortocoronary vein bypass on left ventricular function

The diagnosis, angiographic evaluation and surgical treatment by aortocoronary vein bypass are described in a 3½-year-old girl with anomalous origin of the left coronary artery from the pulmonary artery. The anomaly had resulted in cardiac dilatation, diminished left ventricular contractility, an aneurysm of the left ventricular free wall and mitral regurgitation.At the postoperative cardiac catheterization the graft was demonstrated to be patent, but a significant proportion of the flow to the left coronary artery was derived from anastomotic connections with the right coronary artery. The most striking evidence of improvement was obtained from the left ventricular volume studies which showed that the end systoiic volume had decreased from 85 to 49 ml./m.² with an increase in ejection fraction from 0.39 to 0.62, suggesting enhanced left ventricular contractility after surgery.The patient continues to do well and is free from symptoms.     

Mitral re-repair and right coronary fistula closure: advantage of minimally invasive approach

A 51-year-old man developed severe mitral regurgitation 10 years after previous mitral valve repair; the echocardiographic images showed a remarkable eccentric jet toward posterior wall of left atrium associated with a high degree of pulmonary vein retrograde flow. The coronary arteriography pointed out no pathologic lesions but a coronary fistula from the proximal right coronary to the right atrium. The standard approach was avoided, and a right anterolateral minithoracotomy was chosen, providing an excellent view. Under cardiopulmonary bypass and mild hypothermia, the mitral valve was re-repaired, and a new ring was implanted. After aortic cross-clamp release, the right coronary fistula was closed through the right atrium. The postoperative course was uneventful, and the patient was discharged on the fourth postoperative day. In such a high-risk reintervention and concomitant procedure, we think that this different approach may represent a feasible and reliable alternative.     

Primary percutaneous coronary intervention in the left main stem of a monocoronary artery

In a 71-year-old female with evolving anterior wall myocardial infarction, coronary angiography revealed a monocoronary artery which arose from the right sinus of Valsalva. Originating from a short common trunk, the left main stem showed a thrombotic lesion that occluded the left anterior descending coronary artery while the circumflex artery was obstructed. Intracoronary administration of abciximab, followed by stenting of the transition between the left anterior descending coronary artery and the main stem, and final kissing balloon inflation of the bifurcation resulted in an excellent angiographic result and favourable clinical outcome. (Neth Heart J 2009;17:274–6.)     

Anomalous course and branches of human coronary arteries

132 hearts obtained from cadavers were dissected in order to study anomalies in the course and branches of human coronary arteries. Only in 1 heart was a deviation of the circumflex branch of the left coronary artery taking a course inferior to the coronary sulcus observed. The right coronary artery travelled the entire length of the coronary sulcus on the back of the heart and gave both a posterior ventricular and a collateral branch. Circumflex branches of the right and left coronary arteries did not anastomose.     

Multiscale modeling of the cardiovascular system: application to the study of pulmonary and coronary perfusions in the univentricular circulation

The objective of this study is to compare the coronary and pulmonary blood flow dynamics resulting from two configurations of systemic-to-pulmonary artery shunts currently utilized during the Norwood procedure: the central (CS) and modified Blalock Taussig (MBTS) shunts. A lumped parameter model of the neonatal cardiovascular circulation and detailed 3-D models of the shunt based on the finite volume method were constructed. Shunt sizes of 3, 3.5 and 4 mm were considered. A multiscale approach was adopted to prescribe appropriate and realistic boundary conditions for the 3-D models of the Norwood circulation. Results showed that the average shunt flow rate is higher for the CS option than for the MBTS and that pulmonary flow increases with shunt size for both options. Cardiac output is higher for the CS option for all shunt sizes. Flow distribution between the left and the right pulmonary arteries is not completely balanced, although for the CS option the discrepancy is low (50-51% of the pulmonary flow to the right lung) while for the MBTS it is more pronounced with larger shunt sizes (51-54% to the left lung). The CS option favors perfusion to the right lung while the MBTS favors the left. In the CS option, a smaller percentage of aortic flow is distributed to the coronary circulation, while that percentage rises for the MBTS. These findings may have important implications for coronary blood flow and ventricular function.     

Measurement of the flow in coronary artery bypass grafts

The aim of our study was to measure the flow in coronary artery bypass grafts and to compare the flow between two groups of patients. In group A the arterial revascularization was performed with both internal thoracic arteries using as a Y graft and in group B conventional revascularization using left internal thoracic artery (ITA) attached to the left anterior descending artery (LAD) and venous grafts to the other branches of the left coronary artery was performed. The flow in all grafts was measured at six time points during the operation. The cumulative flow at the end of the operation in the group A (arterial Y graft) was 51.8 +/- 24.5 ml/min and in group B (conventional technique) it was 96.8 +/- 41.1 ml/min (p < 0.05). The flow in left ITA to LAD was similar in both groups (27.3 +/- 15.9 ml/min and 26.3 +/- 16.1 ml/min in group A and B). The flow in right ITA (25.2 +/- 18.4 ml/min) was significantly lower than in venous grafts (72.5 +/- 45.5 ml/min). The calculated flow reserve was 2.2 in group A and 2.1 in group B. We found that the cumulative flow in arterial Y graft was lower in comparison with conventional revascularization. This is due to the lower flow in the right ITA branch of the Y graft compared to venous grafts. However based on clinical results, we can postulate that the flow in the Y graft is sufficient to meet the demand of the myocardium originally supplied by the left coronary artery.     

正常小鼠冠状动脉的超声成像技术分析

目的探讨利用高频小动物心脏超声对C57BL／6小鼠冠状动脉进行评价的可行性,为小鼠冠状动脉相关疾病动物模型的制备及其功能评价提供依据。方法采用Vevo770型高分辨小动物超声仪,频率30mHz的宽频探头,对20只健康C57BL／6小鼠于4、8和12周龄时冠状动脉的情况进行观察。测定和分析不同周龄小鼠冠状动脉内径值的变化。结果全部20只小鼠超声均成功检测到冠状动脉。超声心动图显示小鼠4周龄时左冠状动脉主干内径检测值为0．36±0．02mm,右冠状动脉主干内径值为0．29±0．03mm;8周龄时左冠状动脉主干内径值为0．38±0．06mm,右冠状动脉主干内径值为0．37±0．02（mm）;12周龄时左冠状动脉主干内径值为0．38±0．02mm,右冠状动脉主干内径值为0．39±0．03mm。结论利用高频小动物心脏超声可获取正常小鼠清晰的冠状动脉图像,并能准确反映小鼠冠状动脉内径值动态变化。为小鼠冠状动脉疾病模型的制备及其功能评价提供依据。     

Coronary artery anomalies detected by MSCT-coronary angiography in the adult

Background. Before coronary evaluation by modern imaging techniques was feasible, premorbid diagnoses of coronary artery anomalies (CAAs) were usually made fortuitously by invasive coronary angiography (ICA). However, this technique is limited by its invasive and projectional nature. Coronary magnetic resonance angiography (CMRA) and multi-slice computed tomography (MSCT) broadened clinical information by enabling visualisation of the coronary arteries in their anatomical environment. Methods. This case series visualises and reviews anomalous coronary artery from the opposite sinus (ACAOS) and coronary artery fistulae. All CAAs were detected by means of 64-slice dual source computed tomography after 1000 cardiac scans at the Erasmus MC, Rotterdam, the Netherlands. Results. Eight ACAOS cases, one anomalous left coronary artery from the pulmonary artery (ALCAPA) and one congenital aneurysm of an aortic sinus were found. Seven out often detected CAAs were considered malignant whereas three CAAs of the ACAOS type (retroaortic path) were considered benign. Significant coronary artery disease was found in three out of eight ACAOS cases. In one of the ACAOS cases complete evaluation of the anomalous coronary artery was limited by motion artifacts. All five cases of right ACAOS were referred for MSCT because the right coronary artery could not be located by invasive angiography. Conclusion. All CAAs were easy to diagnose because of 3D imaging and high temporal and spatial resolution. High resolution made it possible to not only depict coronary artery abnormalities, but also to quantify luminal and vessel properties such as stenosis grade, aspects of plaque, anomalous vessel length, luminal area ratio and the asymmetry ratio. Because of its comprehensiveness, MSCT can be an effective imaging modality in patients suspected of coronary artery abnormalities caused by coronary artery disease, CAAs, or a combination of both. (Neth Heart J 2008;16:369-75.)