Pediatric echocardiographic patterns: analysis of structural cardiovascular development

For decades the pulmonary circulation was not considered as important as the systemic ("greater") circulation. However, pulmonary hypertension can arise because of many diseases of the heart and lung. Therefore, increasing efforts in research have been undertaken leading to a profound increase in understanding pulmonary vascular physiology and pathophysiology. This review discusses basic physiology, clinical concepts, and treatment options for pulmonary hypertension and the related right ventricular heart failure focusing on secondary pulmonary hypertension in patients during anesthetic procedures. Physiology of Pulmonary Circulation The pulmonary vascular bed is a high-flow, low-pressure circulation system. Pulmonary vessels have less resistance in comparison to the systemic circulation under normal conditions because of higher compliance of pulmonary precapillary arterioles with a thinner media and less smooth muscle cells (SMCs) compared with the corresponding systemic arterioles. In addition, the cross-sectional area of the pulmonary vascular bed is large and highly distensible with recruitable vessels available to accommodate increase in flow resulting in low pressure and low resistance. In contrast to the systemic arteries, pulmonary vessels constrict with hypoxia (Euler-Liljestrand reflex) and relax in the presence of hyperoxia. Furthermore, changes in cardiac output (CO), airway pressure, and gravity affect the pulmonary more than the systemic circulation. Increases in CO distend open vessels and recruit previously closed vessels. Therefore, the cross-sectional area of pulmonary circulation enlarges and results in a decrease in pulmonary vascular resistance (PVR). An increase in CO has very little effect on pulmonary arterial pressure (PAP) because of the recruitment and distension of pulmonary vessels. An increased PAP or left atrial pressure (LAP) may also distend and recruit pulmonary vessels. Clinically, this means that enhanced CO caused by the administration of inotropic drugs or enlarged blood volume will passively decrease PVR. The contribution of intra- and extraalveolar vessels accounts for the unique U-shaped relationship between lung volume and PVR, which is minimal at functional residual capacity and increased at large and small lung volumes (Fig. 1). Clinically, this may be observed when hyperinflation of the lungs greatly increases PVR.Figure 1: Relationship between lung volume and pulmonary vascular resistance (PVR) (123). RV = residual volume, FRC = functional residual capacity, TLC = total lung capacity.Gravity influences the distribution of blood flow in the pulmonary circulation. Blood flow as well as ventilation increases in the dependent areas of the lung. The relationship between alveolar and hydrostatic pressure implies important clinical consequences. Patients with unilateral lung disease should be positioned with the diseased side up as was already shown by Remolina et al. (1). Lying with the sick lung dependent resulted in the worst gas exchange and the lowest arterial oxygen pressure (1). Application of high levels of positive end-expiratory pressure (PEEP) will narrow the capillaries in the well-ventilated lung areas and divert flow to less well-ventilated or nonventilated areas. Therefore, a decrease in PaO2 is the consequence. Constantly changing hemodynamics, mechanical forces, and hormonal environment influence the vascular endothelium and the underlying SMCs. Under normal circumstances, the interaction between endothelium and SMCs results in a low vascular resistance in the pulmonary circulation. An increasing number of molecules seem to be involved in these biochemical transductions: L-arginine-nitric oxide (NO)-cyclic-3′-5′guanosine monophosphate (cGMP) pathway seems to have a predominant role (2). Physiological agonists such as bradykinin and acetylcholine as well as mechanical stress derived from pulmonary blood flow can activate endothelial cells. This results in oxidation of the guanidino-nitrogen atom of the amino acid L-arginine by the constitutive NO synthase to form and release NO. NO diffuses from endothelial cells to the SMCs, and produces relaxation by activating guanylate cyclase with increasing intracellular cGMP (2). Pulmonary endothelial cells (surface area of 200 m2 in the adult) have a very strategic location: they are exposed to the entire CO, link the pulmonary and systemic circulation, and also regulate SMC tone by signaling to the vascular wall. Endothelial cells both seem to sense local shear stress and to initiate a response (e.g., production of NO) in order to accommodate rapid changes of blood flow. NO and prostacyclin (PGI2) support oxygenation and lung inflation in dilating the pulmonary vasculature after birth, keeping a key regulatory role in the lung because of its prompt, local powerful action compared with a brief half-life time (3). Pathophysiology of Pulmonary Hypertension It is now understood that the balance between vasoconstrictors and vasodilators and mitogenic and antimitogenic factors derived from the endothelium is disturbed in situations with an increase in PAP (4, 5). Endothelial dysfunction is promoted by hypoxia, acidosis, free radicals (6), inflammatory mediators, shear stress caused by increased pulmonary blood flow from left-to-right intracardiac shunt (7), and fibrin from thromboembolism (8). There is no widely accepted range for normal PAP. However, mean PAP >25 mm Hg (normal 15 mm Hg) at rest or >30 mm Hg with exercise is generally accepted as indicative for pulmonary hypertension (9). The enhanced pressure in the pulmonary circulation is associated with an increase in PVR and results in a progressive inability of the right ventricle (RV) to sustain its output leading to RV hypertrophy and RV failure depending from acute or chronic changes (4). In a study by Vizza et al. (10), prevalence of RV dysfunction (defined as RV ejection fraction [RVEF] <45%) was significantly higher in patients with pulmonary hypertension compared with all other groups with end-stage pulmonary disease. Determination of PVR is difficult in clinical settings even if the respective variables such as LAP, mean PAP, pulmonary capillary wedge pressure (PCWP), and thermodilution CO are measured directly because of their intrinsic inaccuracies. Therefore, indirect estimations use the equation: Normal PVR is approximately 1.1–1. 4 Wood units or about 90–120 dynes · s · cm−5, and a PVR >300 dynes · s · cm−5 is indicative of pulmonary hypertension. Pulmonary blood flow and volume are not always equal to or correlated with CO, because of intracardiac or other shunts. Vascular Remodeling Chronic pulmonary hypertension leads to structural alterations of the pulmonary vasculature and to a progression of histological changes known as "vascular remodeling" (11). Under physiological conditions, pulmonary arterioles are thin-walled vessels with the media occupying only 7% of the vessel thickness. The major finding in remodeled vessels caused by a chronic stimulus like hypoxia is the increase in SMCs in already muscularized arteries and extension of SMCs into vessels that are normally thin and nonmuscular (12) and thickening of the adventitial layer (13). Thickening of the adventitial layer is the result of marked proliferation of the fibroblasts, which has been shown to be modulated by protein kinase C and mitogen-activated protein kinase (14). After the proliferative response, there is an increase in adventitial connective tissue including a switch in SMC phenotype to a more synthetic cell that is responsible for deposition of increased connective tissue (12). This deposition of most notably collagen is probably a protective mechanism strengthening the vascular wall against the increase in intravascular pressure (15). Additionally, damage to intimal endothelium as well as intimal hyperplasia and fibrosis can be detected (5). The central regulatory function of the pulmonary endothelium is underlined by the fact that a dysfunctional endothelium can influence the development of pulmonary hypertension at the levels of coagulation control, vasomotor tone, and pulmonary vascular remodeling (16). The major stimulus for remodeling is hypoxia (17). The increase in PVR is predominantly caused by the hypoxic pulmonary vasoconstriction (HPV), which resides primarily distal to lobar arteries and proximal to the capillaries and occurs in resistance arterioles 30–300 μm in diameter (18). Pulmonary arteriolar SMC oxygen-sensitive voltage-dependent potassium channels seem to have an important role for initiating HPV (19). Inhibition of these channels by decreased PO2 inhibits outward potassium current, causing membrane depolarization and calcium entry through voltage-dependent calcium channels (19). The main determinant of HPV is alveolar PO2, but mixed venous PO2 contributes to approximately 20% of the response (19). HPV is inhibited by substances such as substance P, atrial natriuretic peptides, by mediators such as PGI2 and NO, by increased LAP, by increased alveolar pressure, and by alkalosis. Enhanced HPV, however, could be observed with acidosis, by using epidural anesthesia and by inhibition of cyclooxygenase or NO synthase (19). Subsequent increases in PAP are predominantly caused by vascular remodeling as well as secondary polycythemia. Proliferation and differentiation of pericytes and intermediate cells to SMCs are a consequence of chronic exposure to hypoxia followed by elastin and collagen synthesis and deposition (20). In addition, vasomotor function may be altered in these remodeled vessels (20). Among the candidates of biochemical mediators of hypoxia-induced pulmonary hypertension are voltage-gated potassium channels, mitochondrial oxygen sensing, and an imbalance in vasoactive factors (see below) (21). Remodeling also happens in inflammation secondary to sepsis (22) and in patients with chronic lung disease (23) and adult respiratory distress syndrome (ARDS) (24). The inflammation process and increased blood flow lead to vascular remodeling by damaging endothelial cells and disturbs the sensitive balance of pulmonary tone. Under physiological conditions, these cells eliminate factors that initiate SMC proliferation such as angiotensin II, endothelin, thromboxane A2, prostaglandin H2 and O2−(25). Alternatively, damaged endothelial cells may fail to produce inhibitory factors, possible heparin-like substances, which normally decrease SMC proliferation. Removal of the inciting stimulus can lead to reversal of structural changes. Etiology of Pulmonary Hypertension Pulmonary hypertension is caused by a variety of acute and chronic pulmonary diseases with an increase in PAP (Table 1). In contrast to secondary pulmonary hypertension, primary pulmonary hypertension (PPH) is not related to a known underlying disease.Table 1: World Health Organization Diagnostic Classification of Pulmonary Hypertension (1998) (21)PPH PPH is rare (1–2 per million in the general population), affects more women than men (1.7:1), sometimes has a familial link (6% of all cases), and has a poor prognosis (median survival 2–3 yr after diagnosis). PAP usually is >60 mm Hg in these patients (9, 26). PPH is a diagnosis of exclusion, because it is idiopathic. Hypoxemia and increased PVR resulting in an increased PAP can lead to RV failure and death. Altered vasoreactivity alone is not responsible for PPH. Vascular remodeling contributes to the vasculopathic process. However, regression of extensive changes caused by hypertension can occur. Secondary Pulmonary Hypertension Secondary pulmonary hypertension is more common, the increases in PAP are generally less severe (mean PAP <40 mm Hg) (26), and it is also more frequently seen in the perioperative period. Therefore, in this review, we have focused on secondary forms of pulmonary hypertension. Most cases of pulmonary hypertension are secondary to cardiac or pulmonary disease (Table 1) and may be reversible in some cases. Clinical manifestations might be overshadowed by the symptoms of the underlying disease (Table 2). Blood vessel changes are not confined to PPH but are also found in many forms of secondary pulmonary hypertension. Congenital cardiac disease with an atrial or ventricular septal defect causes an increase in pulmonary blood flow. Over time, in response to the increased blood flow, the PVR is increased and eventually will exceed systemic vascular resistance (SVR). Under these conditions, blood flow is shunted from right to left, often referred to as Eisenmenger syndrome. In contrast, high-pressure shunts such as those associated with truncus arteriosus, ventricular septal defects, or patent ductus arteriosus (28) cause pulmonary hypertension much earlier and it is often more severe.Table 2: Common Symptoms and Signs of Pulmonary Hypertension (27)The relevance of pulmonary hypertension in the perioperative period was shown in a study by Reich et al. (29). In patients undergoing coronary artery bypass grafting with cardiopulmonary bypass (CPB), the development of pulmonary hypertension was a significant predictor of increased mortality and perioperative myocardial infarction (29). The severity of the observed vasoconstriction correlates with the extent of CPB-induced endothelial injury (30). Levels of thromboxane A2(31) and endothelin (32) were increased after CPB, whereas PGI2 and NO levels were reduced (33). For a long time, it was thought that CPB did not cause any pulmonary endothelial injury due to ischemia-reperfusion because of the protection via the vasa vasorum of the bronchial circulation. It has been shown, however, that total CPB may cause complete cessation and reestablishment of pulmonary artery flow, with inadequate pulmonary endothelial blood supply by the vasa vasorum, resulting in an ischemia-reperfusion injury (34). The intraoperative injury and postoperative endothelial dysfunction of the pulmonary endothelium is promoted by the following factors (2): Preoperative status of the pulmonary vascular bed, i.e., pulmonary hypertension, valvular pathology; chronic obstructive pulmonary disease, pulmonary thromboembolism, and shear stress caused by increases in pulmonary blood flow and pressure of left-right intracardiac shunt. Bando et al. (35) demonstrated in patients with congenital heart disease that preoperative pulmonary hypertension, absence of mixed venous saturation monitoring, and absence of prophylactic α-blockade significantly increased postoperative pulmonary hypertension. Intraoperative vasospastic stimuli, such as hypoxia, hypercarbia, acidosis, duration of total CPB, ischemia-reperfusion injury, free radical formation, inflammatory mediators, pulmonary leukosequestration, excess thromboxane or endothelin production, and microemboli. Postoperative factors such as adrenergic tone, atelectasis, and HPV. Other examples of pulmonary hypertension during anesthesia are shown in Table 3.Table 3: Occurrence of Pulmonary Hypertension During Anesthesia (36)Symptoms and Diagnosis of Pulmonary Hypertension The most common clinical signs of pulmonary hypertension are dyspnea and fatigue (9) (see also Table 2). These major symptoms might be explained through the associated decrease in CO; however, an exact etiology is still missing. On physical examination, a prominent P2 heart sound, a tricuspid regurgitation murmur, an atrial (S3), or ventricular (S4) heart sound might be heard. The chest radiograph can display an enlarged main pulmonary artery and enlarged hilar vessels, whereas the electrocardiogram shows a right axis deviation suggesting right ventricular hypertrophy. However, the validity of acute changes in the electrocardiogram attributed to right heart insufficiency in the intraoperative period is limited. Transesophageal echocardiography (TEE) as a more advanced technique diagnoses pulmonary hypertension indirectly attributed to RV enlargement, paradoxical interatrial and interventricular movement, partial systolic closure of pulmonary valve, tricuspid regurgitation, and an increased RV systolic pressure (Fig. 2). There are two approaches to obtaining hemodynamic measurements using TEE. By using spatial imaging methods, cardiac chamber volumes can be estimated to obtain both preload and stroke volume. In addition, Doppler-based methods can be used to estimate both right ventricular filling and CO (37). Because of the inherent difficulty in developing a simple geometric model of the RV, regression equations may inaccurately predict ventricular volumes. In addition, TEE measurements are further altered by changing loading conditions, which alter both the size and geometry of the RV. Although TEE evaluation of RV volume can be difficult to determine in adults, high-quality images are routinely obtained in pediatric patients. One of the main limitations on further use of TEE is the availability of equipment as well as costs of echocardiography machines and probes, and expertise (37). The definitive diagnosis is obtained by right heart catheterization with direct measurement of PAP, right atrial pressure (RAP), PCWP, and CO.Figure 2: Transesophageal echocardiography for diagnosis of pulmonary hypertension. Dilated right ventricle (RV) in the midesophageal four chamber view. The figure shows the classical septal (S) interventricular shift to the left side. RA = right atrium, LA = left atrium, LV = left ventricle.RV and Pulmonary Hypertension Like the pulmonary circulation, the RV was not considered as important as the left ventricle (LV) in maintaining normal hemodynamics and counted for a long time as a "quantite negliable" (38). Today it is recognized that RV and LV are interdependent and both have vitally important functions. The RV is a thin-walled, highly compliant, but poorly contractile chamber. Under normal loading conditions and when function is not compromised, RV ejects blood against 25% of the afterload of the LV, resulting in a smaller RV wall thickness (39). The RV is bound by the RV free wall and the interventricular septum. Failure of the septum (e.g., because of ischemia) to contract normally will decrease RV systolic function. Blood supply for the RV and the septum depends mostly on whether a right or left dominant, or a "balanced" coronary circulation is present. Usually the right and the left anterior descending coronary artery supply the septum and parts of the free wall of the RV. The continuous pressure gradient between the aorta and the RV (coronary perfusion pressure) is responsible for the coronary blood flow to the RV free wall throughout systole and diastole (40). Therefore, the RV blood/oxygen supply is proportional to the systemic pressure but inversely proportional to the RV pressure. Systemic hypotension or increased RV pressure results in a decreased RV coronary perfusion pressure (41). Vlahakes et al. (42) previously showed that right heart performance is directly related to systemic pressure during pulmonary hypertension. RV function is very sensitive to increased RV preload or afterload, septic shock, coexistent LV dysfunction, or right coronary artery occlusive disease (43, 44). In a fundamental study, Urabe et al. (45) demonstrated that an increase in the afterload of the RV resulted in a rightward shift of the relationship between perfusion pressure and regional shortening. Also, end-diastolic segment lengths increased significantly after banding of the pulmonary artery. In contrast to LV performance, RV function is relatively sensitive to increases in afterload. Acute increase in mean PAP above approximately 40 mm Hg results in a significant decrease in RVEF even in the presence of a normal RV contractility. However, gradual increases in afterload are well tolerated, because the RV has time to assemble new sarcomeres in parallel to increase wall thickness (39). In the presence of decreased RV contractility, the RV is even more susceptible to acute increases in afterload. The decrease in RVEF results from a disproportionate increase in end-systolic volume compared with end-diastolic volume (41). The RV is less preload-responsive than the LV such that a given increase in preload results in a smaller increase in stroke work. Therefore, attempts at volume loading may be less effective in increasing RV output compared with volume loading of the In addition, volume loading may even the of RV oxygen (41). Vlahakes that two important in the of right heart RV afterload be reduced and systemic pressure be or Normal and are for maintaining normal RV function The of is as important for RV as it is for LV RV performance is by both intrinsic factors of the RV as well as factors afterload, of the pressure, right coronary artery perfusion pressure, LV performance, and the contractile of the interventricular of the LV function like coronary artery disease, heart valvular heart disease, or systemic hypertension influence RV function by ventricular Also, a RV and right can shift the interatrial and interventricular septum and the left and LV end-diastolic volume. venous pressure not on RV filling pressure and volume because it is dependent on the compliance of the RV in the tricuspid methods, and imaging are and more in the RV RV dysfunction caused by increased PAP was demonstrated in patients with chronic pulmonary disease and in patients ventilation can also RV the interventricular septum paradoxical resulting in right heart and decreased LV chamber size In postoperative a decrease in RVEF is observed at levels because of of alveolar vessels and increase in RV afterload significant was between RVEF and increasing of airway pressure by ventilation of the underlying disease has Because symptoms often arise in pulmonary hypertension, the after of signs of RV insufficiency is yr in for lung disease, as well as systemic for chronic lung are of of pulmonary hypertension. of which causes and and for can also definitive of congenital heart diseases can and mortality from postoperative pulmonary hypertension common clinical is the of the right heart because of chronic left heart In this of the LV has of the right heart by means of coronary or coronary artery bypass treatment and should PVR, which can be with the following and factors the pulmonary oxygenation with oxygen of respiratory acidosis, mm Hg) of a to of respiratory of the lung of release caused by stress and of options for RV dysfunction with increased PVR whereas positive inotropic drugs are the treatment of in RV dysfunction with normal PVR. of RV of RV preload should be considered if central venous pressure is mm Hg It is however, that preload of the RV should be estimated by a simple volume in an increase in mean arterial blood pressure and can increase RVEF with volume if RV is normal and PAP is increased only However, administration of volume also can have in patients with right heart treatment in for (defined as patients no increase in to the with central venous pressure mm of RV of the of the pulmonary circulation of CO and RV failure previously or vasodilators should be keeping in to a significant decrease in the decrease in the in RV stroke volume, systemic hypotension can be the consequence. is thought to produce by calcium channels has other such as the to NO synthase activate and release in both endothelial and SMCs. of SMCs is by both release of NO and direct of SMCs has a half-life it is relatively for the pulmonary circulation. It has been shown to be a and of other drugs to produce pulmonary in of patients with PPH a but there are no observed because of the small In contrast to treatment with that to reduced PAP and PVR in patients with secondary pulmonary hypertension treatment did not any This might be explained by the fact that on their to vascular remodeling The angiotensin reduced PAP and PVR in patients with secondary pulmonary hypertension 4 after have been shown to be effective in the treatment of pulmonary hypertension secondary to connective tissue vascular disease but not in patients with treatment was because of the on venous The of with calcium in secondary pulmonary hypertension seems to on the of PAP, i.e., the higher the of PAP, the less effective the of to the of on PAP in patients with pulmonary showed that a in PAP in of The in PAP in patients with the and the in PAP with clinical Although these drugs have shown their they have severe if used it is that calcium treatment should be to to Patients with pulmonary hypertension and severe clinical right heart failure (mean mm CO should be from treatment with calcium because of the inotropic of these by or more responsible for the of monophosphate leading to an increased of these with increased LV and pulmonary given have been used in patients with pulmonary hypertension after cardiac was shown for cardiac patients with increased PVR to pulmonary systemic It also seems to have an pulmonary effect to The PGI2 was in to PAP in PPH It is by the vascular endothelium and via prostaglandin to cyclase with following increase of PGI2 production is in patients with pulmonary hypertension of PGI2 may in to these are an inhibition of both and SMC proliferation from treatment of PGI2 or its also PAP in pulmonary hypertension of the pulmonary hypertension after heart in or pulmonary hypertension secondary to connective tissue diseases in a

Indonesia has significant fisheries potential due to its vast waters. Its abundant fishery resources have strong export potential. However, export activities often face challenges that cause export volumes to fluctuate. This fluctuation is influenced by various factors. These factors can be minimized using statistical methods such as Principal Component Analysis (PCA) and Factor Analysis. This study includes data characterization for each variable and testing PCA and factor analysis assumptions, including multivariate normality testing, independence testing (Bartlett's test), sampling adequacy (KMO test), anti-image correlation testing, PCA testing, and factor analysis. The results indicate that the percentage contribution of fisheries to GDP, the number of coastal villages with disaster mitigation facilities, and the average daily per capita calorie consumption from fish are relatively less dispersed and not highly variable around the mean. Additionally, all data meet the assumptions, and the sample size is adequate. Factors such as aquaculture pond production and the percentage contribution of fisheries to GDP sufficiently explain the data variations.

AIUM Practice Parameter for the Performance of Fetal Echocardiography.

Arterial switch in a 1146-gram neonate with transposition of the great arteries and an intramural coronary artery

This review focuses on the effects of altitude exposure from 1 to several days or weeks as occurs in tourists, trekkers, and mountaineers who visit high altitude and normally reside near sea level. We briefly review the acute physiological adjustments and early acclimatization that occur in the cardiovascular system and the lungs of healthy individuals. These ensure life-sustaining oxygen delivery to the tissues despite a reduction in the partial pressure of inspired oxygen between 20% and 60% at 2500 and 8000 m, respectively. One of the acute adjustments, hypoxic pulmonary vasoconstriction (HPV), may be disadvantageous in those with a vigorous response and lead to 2 potentially lethal illnesses, high-altitude pulmonary edema (HAPE) and subacute mountain sickness (SAMS), which we present in more detail. Finally, on the basis of knowledge about the acute physiological adjustments and acclimatization and, when available, a review of the literature, we discuss the high-altitude tolerance of patients with coronary artery disease, congestive heart failure, arrhythmias, systemic hypertension, and pulmonary hypertension. ### Circulation The major effects of acute hypoxia on the heart and lung are shown in Figure 1. Hypoxia directly affects the vascular tone of the pulmonary and systemic resistance vessels and increases ventilation and sympathetic activity via stimulation of the peripheral chemoreceptors.1 Interactions occur between the direct effects of hypoxia on blood vessels and the chemoreceptor-mediated responses in the systemic and pulmonary circulation. Figure 1. Effects of hypoxia on systemic and pulmonary circulation. Unraveling the underlying mechanisms of the hypoxic vasodilatation of systemic arterioles is an active area of research. Several mechanisms appear to regulate local oxygen delivery according to the needs of the tissues2,3; for instance, the release of ATP from red blood cells and the generation of NO by various ways appear to regulate local oxygen delivery according to the needs …

The aim of the study was to compare contraction initiated by intracellular Ca2+ release in the middle cerebral, coronary and pulmonary arteries of the sheep. With all three arteries from the sheep, incubation in Ca(2+)-free physiological salt solution (PSS) reduced agonist-induced contraction much more than occurred with the rabbit aorta. The intracellular Ca2+ store appeared to be of limited capacity, since contraction was transient in Ca(2+)-free conditions with most agonists. In the middle cerebral artery, contraction in Ca(2+)-free conditions was much reduced if a previous contraction had been obtained (for 5-hydroxytryptamine, 5-HT, from 11 +/- 4 to 1 +/- 0.5% of control contraction in 2.5 mM Ca2+), suggesting that the previous contraction had partly discharged the intracellular Ca2+ store. Contraction was less affected in the pulmonary artery and almost unaffected in the coronary artery (for 5-HT, from 15 +/- 1 to 11 +/- 1%) by a previous contraction in Ca(2+)-free conditions. Rings prepared from small branches of the pulmonary and coronary arteries were affected by Ca2+ deprivation in a similar manner to large diameter pulmonary and coronary artery rings. In Ca(2+)-free PSS, contraction induced by prostaglandin E2 was almost eliminated (3 +/- 1% of control contraction in 2.5 mM Ca2+), contractions induced by 5-HT and noradrenaline were reduced, and contraction induced by the thromboxane mimetic U46619 was least affected (up to 73 +/- 8%). Increasing agonist concentration from EC50 to the maximally effective concentration raised the percentage contraction remaining in the middle cerebral artery (for noradrenaline from 7 +/- 2% to 12 +/- 3%) but not in the pulmonary artery (for noradrenaline from 22 +/- 2% to 24 +/- 6%). The present study has revealed notable differences, in coupling to intracellular Ca2+ release between the three vascular territories studied.

The purpose of this study was to evaluate the use of a triphasic contrast bolus for ECG-gated CT in the assessment of chest pain by measuring vascular luminal attenuation and determining the degree of contrast-related streak artifact. We reviewed the images from 44 ECG-gated CT examinations performed with a coronary contrast bolus modified for imaging of the entire chest. Luminal attenuation achieved with the resulting triphasic bolus was measured at specified vascular locations in the right side of the heart, pulmonary arteries, coronary arteries, and thoracic aorta. The occurrence of contrast-related streak artifact was recorded, and artifact severity was scored on a subjective 4-point scale. The mean attenuation values in the pulmonary arteries (345.3 +/- 136.7 HU), coronary arteries (340.8 +/- 82.5 HU), and thoracic aorta (386.4 +/- 67.2 HU) were above a diagnostic threshold of 200 HU. Although there was no significant difference between the mean arterial values, the right-heart attenuation (281.6 +/- 121.8 HU) was significantly lower than the attenuation in the other two locations. On a location basis, 92.2% of the 1,972 arterial measurements were above the 200-HU threshold. Streak artifacts were found in 21 examinations (47.7%), and none was scored as severe. Statistical analysis revealed that the occurrence of streak artifact increased with higher right-heart attenuation. In this series, a triphasic contrast bolus for ECG-gated whole-chest CT consistently achieved arterial attenuation above a diagnostic threshold in the pulmonary arteries, coronary arteries, and aorta. Right-heart attenuation was simultaneously reduced, which is important for decreasing the prevalence and severity of streak artifacts.

Anomalous origin of the right coronary artery from the pulmonary artery (ARCAPA) is rare. Unique anatomical characteristics observed include tethering secondary to the extensive collateral vessels, severe native coronary tortuosity, and massive dilation of the coronary arteries. This requires specific technical consideration to ensure safe translocation. A single-center retrospective review of six patients with ARCAPA was performed. Echocardiographic and computerized tomography scan data were analyzed for anatomical and functional cardiac characteristics. Operative techniques were analyzed, which reflected an evolution toward a modified-trapdoor technique. Five children presented with asymptomatic murmurs and one adult patient with unstable angina. All patients underwent successful surgical correction. The modified trapdoor technique provided the most ideal geometry for coronary transfer secondary to its anatomical characteristics. Two patients had coronary button transfers above the sinotubular junction using vertical stab incisions, one had the button implanted after excising part of the aortic wall, and last three patients had modified trapdoor incisions. Mean cardiopulmonary bypass and cross-clamp times were 170 ± 27 minutes and 99.5 ± 29 minutes respectively. The average hospital stay was five days and there were no mortalities. Anomalous right coronary from the pulmonary artery's unique anatomical characteristics require a coronary transfer technique different from that performed in aortic root replacement. In some respects, our modified technique resembles coronary transfers used in difficult arterial switch operations. The use of a modified trapdoor incision simplifies coronary transfer and may minimize coronary kinking and subsequent complications related to coronary transfer.

Pulmonary Hypertension: From an Orphan Disease to a Public Health Problem

Right Ventricular–Pulmonary Vascular Interactions: An Emerging Role for Pulmonary Artery Acceleration Time by Echocardiography in Adults and Children

The arterial (aortic and pulmonary) roots, although apparently of a simpler design, as compared with the atrioventricular valves, depict a more refined, more subtle and still less understood structure and function. The aortic root is constituted of interdependent elements: the sinuses, the leaflets, the interleaflet triangles, the sinotubular junction and additional “annuluses”, and lodges the origin of the coronary arteries. The normal gross anatomy, histology and physiology of the aortic root are synthetically described in order to underscore the importance of a thorough diagnostic interrogation while also presenting some limits of the standard measurements. The characteristics of the diseased aortic root are subsequently described offering a useful guide for a complete and clinically and surgically relevant diagnostic picture, for elaborating the most suited therapeutic indication in the individual patient and for the best and most accurate surgical procedure to be applied.

Article1 April 1955ABERRANT CORONARY ARTERIES: EXPERIENCES IN DIAGNOSIS WITH REPORT OF THREE CASESW. C. SWANN, M.D., F.A.C.P., S. WERTHAMMER, M.D.W. C. SWANN, M.D., F.A.C.P.Search for more papers by this author, S. WERTHAMMER, M.D.Search for more papers by this authorAuthor, Article, and Disclosure Informationhttps://doi.org/10.7326/0003-4819-42-4-873 SectionsAboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinkedInRedditEmail ExcerptIn the last few years interest in congenital heart disease has increased inasmuch as surgical treatment is now possible in certain types. An attempt is now usually made to diagnose clinically and to classify anatomically the type of malformation present. Some malformations are difficult to diagnose, requiring such elaborate technics as catherization of the heart chambers and gas analysis of the blood. Many malformations can be correctly diagnosed by ordinary clinical means. Such a malformation is the anomalous origin of the left coronary artery from the pulmonary artery. This condition is very rare and only 54 cases have been so...Bibliography1. DenkoHagerty JVCS: Anomalous origin of the left coronary artery from pulmonary artery, Arch. Path. 56: 142 (Aug.) 1953. Google Scholar2. Taussig HB: Congenital malformations of the heart, 1947, The Commonwealth Fund, New York, p. 320. Google Scholar3. Kaunitz PE: Origin of left coronary artery from pulmonary artery, Am. Heart J. 33: 182 (Feb.) 1947. CrossrefMedlineGoogle Scholar4. GasulLoeffler BME: Anomalous origin of left coronary artery from the pulmonary artery (Bland-White-Garland syndrome), Pediatrics 4: 498 (Oct.) 1949. MedlineGoogle Scholar5. EidlowMackenzie SER: Anomalous origin of left coronary artery from the pulmonary artery, report of a case diagnosed clinically and confirmed by necropsy, Am. Heart J. 32: 243 (Aug.) 1946. CrossrefMedlineGoogle Scholar6. BlandWhiteGarland EJPDJ: Congenital anomalies of coronary arteries, report of an unusual case associated with cardiac hypertrophy, Am. Heart J. 8: 787, 1933. CrossrefGoogle Scholar7. Wuethrich R: Ueber den Abgang der Art. coronalis sinistra aus der Art. pulmonalis, Zugleich ein Beitrag zum Problem des ploetzlichen Todes, Cardiologia 18: 153, 1951. Google Scholar8. Abbott ME: Congenital heart disease, in Osler, Modern medicine, Vol. 4, 1928, Lea & Febiger, Philadelphia. Google Scholar9. EdmondsSeelye HWWB: Endocardial sclerosis, Pediatrics 7: 651 (May) 1951. MedlineGoogle Scholar10. GrayzelTennant DMR: Congenital atresia of tricuspid orifice and anomalous origin of coronary arteries from pulmonary artery, Am. J. Path. 10: 791, 1934. MedlineGoogle Scholar11. Limbourg M: Ueber den Ursprung der Kranzarterien des Herzens aus der Arteria pulmonalis, Beitr. z. path. Anat. u. z. allg. Path. 100: 191, 1937. Google Scholar12. MaloneyBlalock JVA: Problems in cardiovascular surgery, Ann. Int. Med. 40: 1 (Jan.) 1954. LinkGoogle Scholar This content is PDF only. To continue reading please click on the PDF icon. Author, Article, and Disclosure InformationAffiliations: Huntington, West Virginia*Received for publication July 13, 1954.From the Cardiological and Pathological Services of Saint Mary's Hospital, Huntington, West Virginia. PreviousarticleNextarticle Advertisement FiguresReferencesRelatedDetails Metrics Cited byTotal anomalous origin of the coronary arteries from the pulmonary artery: a systematic reviewSudden infant death with anomalous origin of the left coronary artery from the pulmonary arteryNormal and anomalous coronary arteries: Definitions and classificationMajor anomalies of coronary arterial origin seen in adulthoodOrigin of both coronary arteries from the pulmonary trunk associated with hypoplasia of the aortic tract complex: A new entityZur normalen und pathologischen Morphologie der CoronararterienCongenital Anomalies of the Coronary ArteriesMassive calcification of the myocardiumAnomalous origin of both coronary arteries from the pulmonary artery∗Aberrant origin of left coronary artery combined with mitral regurgitation in an adultAngeborene Herz- und GefäßmißbildungenAberrant Left Coronary ArteryZur Anatomie und Pathologie der CoronargefäßeCurrent pediatric references 1 April 1955Volume 42, Issue 4Page: 873-884KeywordsBloodCongenital heart diseaseCoronary arteriesGas analysisHeartLeft coronary arteryPulmonary arteries ePublished: 1 December 2008 Issue Published: 1 April 1955 PDF downloadLoading ...

Anomalous origin of the left coronary artery from the pulmonary artery: Is reconstruction of a double coronary artery system always necessary?

Atherosclerosis in coronary arteries and aorta among Greenlanders: an autopsy study

Significant pulmonary hypertension during exercise has been observed in patients with severe chronic obstructive pulmonary disease. Although favorable effects on pulmonary function and dyspnea symptoms have been demonstrated, the influence of lung volume reduction surgery (LVRS) on the pulmonary hypertension during exercise is still a controversial subject. A pulmonary function test and 6-minute walking test were performed before and 3, 6, 12 and 24 months after LVRS (n = 12). Pulmonary hemodynamics at rest and during exercise was studied 6 months after operation. Morphology was examined in pulmonary arteries with external diameters of 100 - 200 micro m in the resected lung, and the wall thickness (defined as intima plus media) and percentage wall thickness (percentage wall thickness of the external diameter) of the pulmonary artery were calculated. LVRS improved early-phase pulmonary function and 6-minute walking distance. Although the increase in pulmonary capillary wedge pressure during exercise was significantly ameliorated, exercise pulmonary hypertension did not change after LVRS. The percent wall thickness was highly correlated with Delta Ppa (difference between mean pulmonary artery pressure at rest and mean pulmonary artery pressure during exercise) not only before, but also 6 months after LVRS. LVRS has no significant influence on exercise-induced pulmonary hypertension in patients with severe emphysema. From a histological analysis of the pulmonary artery in the resected lung, remodeling the pulmonary artery that may exist in the remaining lung is possibly one of the important factors preventing postoperative improvement in exercise pulmonary hypertension in patients with chronic obstructive pulmonary disease.