Right Coronary Artery Diameter Research Articles

Evaluation of Coronary Circulation by 13N-Ammonia Myocardial Perfusion Positron Emission Tomography in Patients with Right Coronary Artery Occlusion Due to Kawasaki Disease.

Although occlusion of the right coronary artery (RCA) is common in the remote stages of Kawasaki disease, revascularization of the RCA is challenging in children and is usually managed by observation without intervention. Using adenosine-stress 13N-ammonia myocardial perfusion positron emission tomography, we evaluated coronary circulation in 14 patients (12 males) with RCA occlusion to identify ischemia (myocardial flow ratio < 2.0) in the RCA region and examined hemodynamics, cardiac function, and coronary aneurysm diameter. These variables were also compared in patients with/without RCA segmental stenosis (SS). There were five cases of ischemia in the RCA region. RCA myocardial blood flow (MBF) at rest was higher in patients with ischemia than in those without ischemia, but the difference was not significant (1.27 ± 0.21 vs. 0.82 ± 0.16 mL/min/g, p = 0.2053). Nine patients presented with RCA SS, and age at onset of Kawasaki disease tended to be lower in those with SS. The maximum aneurysm diameter of RCA was significantly smaller in patients with SS (10.0 ± 2.8 vs. 14.7 ± 1.6, p = 0.0239). No significant differences in other variables were observed between patients with/without ischemia and SS. At rest, MBF in the RCA region was relatively well preserved, even in patients with RCA occlusion, and there was no progressive deterioration in cardiac function. Adenosine stress showed microcirculatory disturbances in only half of the patients, indicating that it is reversible in children with Kawasaki disease.

A study of coronary dominance and its clinical significance.

Coronary artery disease is the most common cause of morbidity and mortality especially in the developing countries. The aim of the study was to find out cardiac dominance percentages and its association with coronary artery stenosis among each pattern of dominance. The objectives were to assess coronary vessel morphology of patients within each pattern of dominance, to find if gender differences exist among dominance patterns and also to find the distribution percentages of stenosis among dominance patterns. Four thousand angiograms from patients of Indian origin were studied prospectively after procuring the sanction for the same from the ethical committee of the pre-selected hospitals from four states of South India. Informed consents were obtained. Post coronary artery bypass grafting, post percutaneous coronary intervention patients and patient being diabetic for ≥ 5 years were excluded from the study. Right cardiac dominance was seen in 85.5%, left in 9.7%, and co-dominant in 4.8% cases. The percentages of dominance were almost similar among both genders except for left dominance which were higher among male samples. The diameter of right coronary artery and left circumflex coronary artery coronary arteries were significantly associated with dominance patterns. The prevalence of stenosis was more for left dominance patterns, followed by right dominance patterns and least for co-dominant patterns. There is a necessity to see association between dominance patterns with the coronary artery disease which can help the interventional cardiologists. The disease patterns in the present study were predominantly in the left dominant or in the co-dominant hearts.

Variations in coronary artery diameter: a retrospective observational study in Indian population

Objective: The diameter of coronary arteries varies greatly among general population. The knowledge of variations in coronary arteries helps the clinicians to define abnormalities and plan the treatment. Hence, the present study was aimed to study common primary variations of coronary arteries by angiography in Indian population. Methods: The data for this unicenter, retrospective, observational study was collected from general hospital, Maharashtra, as patient data sheets and coronary angiograms (CAG) reports for a period of 1 year and 8 months. The CAG were studied for variations in main trunk diameter of coronary arteries and range of diameters of coronary arteries. Results: A total of 400 conventional CAGs were observed, of which 17 angiograms showed anatomical variations. The diameter of left coronary artery was more than right coronary artery (RCA) in 90.5% and less in 9.5% of CAGs. Statistically significant difference was observed on comparing the mean diameter of RCA (3.40(0.81 mm) and left coronary artery (4.52(0.95 mm; p&amp;lt;0.001). The range of diameter of RCA (1.8 to 6.2 mm) and left coronary artery differed significantly (2 to 7.3 mm; p &amp;lt;0.001). Conclusion: From the results, it was evident that the diameter of left coronary artery was larger than right coronary artery in majority of CAGs.

Feasibility of measuring pericoronary fat from precontrast scans: Effect of iodinated contrast on pericoronary fat attenuation

BackgroundPericoronary adipose tissue (PCAT) attenuation has been identified as a marker for cardiovascular risk. The effect of contrast enhancement on fat attenuation is unknown. We aim to compare precontrast coronary scans to postcontrast CCTA for quantification of pericoronary fat volume and attenuation. MethodsThin slice pre- and post-contrast studies obtained at 120 kVp, heart rate <60, with no plaque or artifact in the right coronary artery (RCA) were selected. Analysis was limited to pixels −30 Hounsfield units (HU) to −190 HU and from 10 mm to 50 mm distal to the RCA origin at a radial distance equal to the vessel diameter. A subgroup with no plaque across all coronaries was also analyzed. ResultsOf 119 study pairs, the average RCA diameter was highly correlated at 3.85 mm (postcontrast) and 3.84 mm (precontrast), r = 0.97, p < 0.0001. The mean attenuation of pre- and postcontrast images was also highly correlated at −87.02 ± 7.15 HU and −82.74 ± 6.54 HU, respectively (r = 0.65, p < 0.0001). Pericoronary fat volume in the −190 to −30 HU range was 396 mm³ lower in the post contrast versus pre-contrast, consistent with higher attenuation (less negative) voxels postcontrast (p < 0.0001). Inter- and intra-reader agreement ranged 95–100% and 90% for precontrast and 85–90% for postcontrast studies, respectively. Subgroup analysis revealed precontrast attenuation −85.59 ± 7.53 HU and postcontrast −82.21 ± 7.15 HU were highly correlated r = 0.67, p < 0.0001. ConclusionPericoronary fat enhances with iodinated contrast, potentially explaining some of its risk-predictive capabilities. Fat attenuation and volume can be reliably measured from precontrast calcium scans, with volume quantification showing particularly strong correlation. Excellent inter- and intra-reader agreement is also demonstrated.

Intravascular assessment of coronary arteries in patients with cyanotic congenital heart disease.

Patients with cyanotic congenital heart disease (CCHD) have been suggested to develop less atherosclerosis than the general population. This study aimed to evaluate the extent of coronary atherosclerosis in patients with CCHD using intravascular ultrasound (IVUS) and near-infrared spectroscopy (NIRS). Fifteen patients with CCHD (women, 9; median age, 53 years) and 14 acyanotic controls (women, 6; median age, 53 years) were examined with IVUS-NIRS of the right coronary artery (RCA). The patients with CCHD presented with a larger RCA diameter than the controls (external elastic membrane diameter, 6.1 [4.8-6.7] vs. 4.7 [4.1-5.1] mm, respectively; p=0.01). No difference in area stenosis was found between the patients and the controls (15.8% [12.3-19.7] vs. 15.2% [9.5-18.8]; p=0.87). The presence of lipid by NIRS was noted in 43% of patients with CCHD and in 92% of the controls; however, no differences in total or max 4 mm lipid core burden index (LCBI) or in plasma lipid profile were found. Patients with CCHD presented with larger coronary arteries than acyanotic controls. No difference in the degree of area stenosis in the coronary arteries was found between the cyanotic and acyanotic patients; however, a lower proportion of patients with CCHD showed a positive LCBI.

A comparative study of established z score models for coronary artery diameters in 181 healthy Korean children.

PurposeThe aim of this study was to investigate the statistical properties of four previously developed pediatric coronary artery z score models in healthy Korean children.MethodsThe study subjects were 181 healthy Korean children, whose age ranged from 1 month to 15 years. The diameter of each coronary artery was measured using 2-dimensional echocardiography and converted to the z score in the four models (McCrindle, Olivieri, Dallaire, and Japanese model). Descriptive statistical analyses and 1-sample t tests were performed.ResultsAll calculated z scores had P values of ≥0.050 using the Kolmogorov-Smirnov test. The one sample t test showed that the mean z scores did not converge to zero except in 1 model, and the mean right coronary artery (RCA) z score was less than zero in all 4 models. The smaller RCA diameter in this study could be associated with the more distal measuring point used to avoid the conal branch. The percentage of subjects with extreme z score values (≥2.0 and ≥2.5) for the left main coronary artery (LMCA) seems to be higher in the Dallaire (4.9% and 3.3%) and Japanese models (7.1% and 3.8%).ConclusionAll 4 models showed statistical feasibility of normal distribution. More precise instructions would be needed for the measurement of the RCA. The higher percentage of extreme z scores for the LMCA is compatible with the basic understanding of anatomic variation in the LMCA.

Impact of the size mismatch between saphenous vein graft and coronary artery on graft patency.

The saphenous vein graft (SVG) is widely used in coronary artery bypass grafting because of its availability and ease of use. However, the patency rate of the SVG grafted to the right coronary artery (RCA) is poor. Diameter mismatch between the coronary artery and SVG is an important cause of graft occlusion. In this study, we assessed how the degree of diameter mismatch affects SVG patency. We reviewed the records of 123 patients who underwent aorto-right coronary artery bypass grafting with an SVG. The patency rate of the SVG, SVG diameter, RCA diameter and SVG-RCA diameter ratio (SR ratio) was assessed based on angiography and CT. The mean SVG diameter was 3.61±0.72mm, the mean RCA diameter was 1.57±0.32mm and the mean SR ratio was 2.37±0.57. Cumulative patency rate of the SVG was 95.5% at the early phase, 85.2% at 1year, and 70.2% at 5years. Multivariate analysis showed that the SR ratio was an independent predictor of SVG occlusion. The cutoff value of the SR ratio was 2.8, calculated from the point of maximal specificity (81.2%) and sensitivity (64.7%), and the area under the ROC curve was 0.734. When the SR ratio was ≤2.8, the 3-year patency rate was 86.1%. A mismatch between SVG diameter and RCA diameter has an impact on the patency rate of the SVG. Evaluation of the saphenous vein before surgery and selection of a graft to minimize mismatch should improve SVG patency.

Effect of Dexmedetomidine on Normal Coronary Vessel Diameter

Dexmedetomidine is a selective alpha2 agonist, which is widely used for conscious sedation in ICU patients. It is being increasingly used to provide conscious sedation in out-of-theatre procedures like CT scan, MRI, endoscopies and catheterization (cath) procedures. There is limited data till date regarding the effect of dexmedetomidine on coronary vessel diameter. The aim of this prospective observational study was to observe the effect of dexmedetomidine on normal coronary vessel diameter. Fifty patients who had come for elective coronary angiography in the cath lab were enrolled in the study. After taking the first shot of the coronary angiogram and confirming that the right coronary artery (RCA) is normal, dexmedetomidine was administered in a dose of 1 µg/kg intravenously over 15 min. Immediately after that, another shot was taken to check the diameter of RCA. Paired Student's t test was used to analyze the data. The mean diameter of RCA before giving dexmedetomidine was 2.7634 ± 0.3189 mm. The mean diameter decreased significantly to 2.6296 ± 0.3379 mm after administration of dexmedetomidine (p value <0.0001). Thus, dexmedetomidine decreases the coronary vessel diameter.

Coronary artery dimensions in the Nepalese population

IntroductionThis study is an attempt to document normal dimensions of the coronary artery branches during life by using quantitative coronary angiography and compare them with international studies. MethodQuantitative coronary angiography (QCA) of 100 patients undergoing evaluation of ischemic heart disease but found to be free of coronary artery disease. Measurement was done using catheter tip as a calibrating object. ResultsOut of 57% right dominant circulation 56.1% were of males and 44% of females. Left coronary dominance was seen in 17% of which 52.9% were male and 47% female, by contrast 26% subjects had co-dominant hearts with 61.5% male and 38.4% female. The mean diameter of the right coronary artery was significantly smaller (p < 0.05) in left dominant hearts as compared to that of dominant right. In contrast the mean diameter of the circumflex artery was significantly smaller (p < 0.05) in right dominant pattern as compared to that of patients with dominant left. Similarly the diameter of circumflex artery was significantly smaller in case of co-dominant type of circulation when compared to that of left coronary pattern of dominancy. DiscussionThe distribution pattern of coronary artery in the Nepalese population is distinct from that specified in the literature and the diameters of right coronary artery and circumflex artery are significantly influenced by the nature of dominance.

1141 The Diameter of Coronary Arteries in Healthy Newborns at Birth, One and Six Months of Ages

ObjectiveThe aim of this study was to determine accurate and validated z-score equations for the normal values of coronary diameters adjusted with growth changes of the neonates by testing three...

The diameter of coronary arteries in healthy newborns at birth, 1 and 6 months of ages

Objective: The aim of this study was to determine accurate and validated Z-score equations for the normal values of coronary diameters adjusted with growth changes of the neonates by testing three different time periods. Methods: Echocardiography was performed on 200 healthy neonates at birth, 1 and 6 months of ages. Several regression models for the left (LCA) and right coronary artery (RCA) diameters were tested with weight, height, body surface area and aortic annulus diameter. Reliable standards for the coronary artery diameters for healthy newborns by determining Z-score equations with appropriate statistical validations were established. Results: The coronary diameters on birth measurements were strongly correlated with birth weight, height, surface area and the diameter of the aortic annulus (Pearson’s R > 0.8, all p < 0.01). There were significant associations between the mean data of weight, height, body surface area, aortic annulus and the LCA and RCA diameters measurements of study subjects at birth, 1 and 6 months of ages (p < 0.05). Z-score graphs of coronary artery diameters and weight of the subjects at three different time (LCA vs. weight at birth, R = 0.82, p < 0.001; LCA vs. weight at 1 month, R = 0.64, p < 0.001; LCA vs. weight at 6 months, R = 0.55, p < 0.001; RCA vs. weight at birth, R = 0.80, p < 0.001; RCA vs. weight at 1 month, R = 0.59, p < 0.001; RCA vs. weight at 6 months, R = 0.49, p < 0.001) were constructed. Conclusion: We present a new set of equations for neonatal Z-score calculation on the basis of a large number of healthy neonates on three different time period consisting of birth, 1 and 6 months of ages. It is clear with this study that the growth in caliber of the coronary arteries is definite and progressive during postnatal time.

Coronary artery dilation among patients with paediatric-onset systemic lupus erythematosus

Objectives: This study aimed to evaluate increased coronary artery dimensions in patients with paediatric-onset systemic lupus erythematosus (SLE) in comparison with healthy controls, and to identify risk factors associated with increased coronary artery dimensions in the SLE patients.Methods: As part of a longitudinal cohort study of coronary artery disease (CAD) in paediatric-onset SLE, 83 children with SLE and 36 healthy controls were enrolled for a cross-sectional analysis. Their coronary artery diameters were measured by echocardiography while their body mass index (BMI), blood pressure, and other cardiovascular factors were recorded. The age at diagnosis, serum uric acid (UA) and creatinine levels, and other lupus-related factors were further evaluated in SLE patients. Data were analysed using linear regression.Results: Mean body surface area (BSA)-adjusted dimensions of the left coronary artery (LCA) and right coronary artery (RCA) were significantly larger in SLE patients than in controls (both p < 0.001). The age at diagnosis, BMI, and serum UA and creatinine levels were associated with LCA and RCA diameters. There were no correlations between the coronary artery diameters and blood pressure, SLE duration, SLE Disease Activity Index (SLEDAI), C-reactive protein (CRP), C3, C4, anti-double-stranded-DNA (anti-dsDNA), or lipid profile. In multivariate analysis, serum UA level, age at diagnosis, and BMI were consistently associated with coronary artery dimensions (p < 0.001, p = 0.008, and p = 0.006 for LCA; p = 0.020, 0.013, and 0.008 for RCA).Conclusions: Increased coronary artery diameters were found in children with SLE and were associated with higher serum UA levels. The pathogenic mechanisms warrant further investigation.

Sudden Death Due to Coronary Tree Hypoplasia

A 20-year-old woman complained for several weeks before her death of unspecific epigastric pains. Such episodes were labeled as "dyspeptic episode." A month later, once again she started to complain about stomach pains, then she collapsed unconscious. She was rushed to a hospital, where she was admitted in cardiorespiratory arrest. An electrocardiogram revealed a ventricular fibrillation. All resuscitation efforts were unsuccessful. The autopsy revealed nonspecific general changes (subpleural petechiae and blood pooling). Dissection of the coronary arteries revealed a normal topography of coronary arteries but a marked hypoplasia of all the subepicardial coronary arteries (maximum diameter of left anterior descending coronary artery = 1.9 mm, maximum diameter of right coronary artery = 1.43 mm). Furthermore, the left anterior descending coronary artery was slightly compressed by a fibrous bridge at about 1.5 cm of its origin; a fibrinoleukocytic thrombus has formed immediately above this bottleneck, obstructing the entire lumen of the artery. Microscopic examination revealed an area of recent myocardial necrosis; diffuse subendocardial fibrosis, with extension into the subjacent myocardium, disorganizing the myocardial fibers; and variable thickening of the vascular walls with periarteriolar fibrosis. Weigert stain has shown marked intimal hyperplasia, either focal or diffuse, in different segments of vascular wall, accompanied by disruption of the internal elastic lamina due to subintimal cellular proliferation, in the medium branches of coronary arteries. The micrometric measurements showed that intimal thickening was at least the size of the media (∼358 vs 356.8 μm) and sometimes double.

Elevated oxidative stress and endothelial dysfunction in right coronary artery of right ventricular hypertrophy

Remodeling of right coronary artery (RCA) occurs during right ventricular hypertrophy (RVH) induced by banding of the pulmonary artery (PA). The effect of RVH on RCA endothelial function and reactive oxygen species (ROS) in vessel wall remains unclear. A swine RVH model (n = 12 pigs) induced by PA banding was used to study RCA endothelial function and ROS level. To obtain longitudinal coronary hemodynamic and geometric data, digital subtraction angiography was used during the progression of RVH. Blood flow in the RCA increased by 82% and lumen diameter of RCA increased by 22% over a 4-wk period of RVH. The increase in blood flow and the commensurate increase in diameter resulted in a constant wall shear stress in RCA throughout the RVH period. ROS was elevated by ∼100% in RCA after 4 wk of PA banding. The expressions of p47(phox), NADPH oxidase (NOX1, NOX2, and NOX4) were upregulated in the range of 20-300% in RCA of RVH. The endothelial function was compromised in RCA of RVH as attributed to insufficient endothelial nitric oxide synthase cofactor tetrahydrobiopterin. In vivo angiographic analysis suggests an increased basal tone in the RCA during RVH. In conclusion, stretch due to outward remodeling of RCA during RVH (at constant wall shear stress), similar to vessel stretch in hypertension, appears to induce ROS elevation, endothelial dysfunction, and an increase in basal tone.

Anomalous Right Coronary Artery Originated From Left Coronary Sinus With Interarterial Course

Anomalous origin of the right coronary artery (RCA) with an interarterial course is a potentially life-threatening anomaly. Clinical significance could depend on its orifice and interarterial course. We evaluated the anomalous RCA on multidetector row computed tomography (MDCT) with clinical correlation. Twenty-five electrocardiography-gated MDCT cases of 24 patients (mean [SD] age, 58.2 [12.3] years; 12 men and 12 women) with anomalous origin of RCA from left coronary sinus with an interarterial course were retrospectively reviewed in 3 hospitals. The cases were evaluated for the location of orifice, a takeoff angle from coronary sinus, mean diameters of RCA (orifice, interarterial, and reference), and the ratio of the diameters of RCA (orifice-reference and interarterial-reference) on MDCT with clinical correlation. The orifice and the interarterial course of all anomalous RCAs were well visualized on MDCT. The narrowest portion of RCA was more frequent in the orifice (16/25 cases) than the interarterial course (6 cases). Three cases revealed the same diameter between the orifice and the interarterial course. The location of the orifice was not correlated with the diameters of anomalous RCA. Takeoff angles were correlated with the relative narrowing of the orifice of anomalous RCA (P = 0.001) and the relative narrowing of the interarterial course (P = 0.007). Only 1 patient showed significant luminal narrowing (>50% stenosis), and this patient showed a minimal takeoff angle and a persistent symptom. The symptom of this patient had disappeared after operation, and postoperative MDCT revealed an increased takeoff angle and no significant luminal narrowing. The other patients showed no significant luminal narrowing. Symptoms were not correlated with the takeoff angle and relative luminal narrowing (orifice-reference and interarterial-reference; P = 0.923, P = 0.915, and P = 0.703). The takeoff angles of anomalous RCA with an interarterial course are correlated with the relative narrowing of luminal diameters at the orifice and the interarterial course. Most cases show a benign nature. Evaluation of the proximal structure of anomalous RCA with an interarterial course could be important in a treatment plan.

Does Coronary Artery Size Really Matter?

To evaluate ischemia in right ventricle (RV) in patients with small caliber of right coronary artery (RCA). The study population consisted of 60 consecutive patients undergoing coronary angiography within 3 months. The patients were divided into three different groups according to lumen diameter of RCA and coronary dominance. Group 1, 2, and 3 consisted of patients with small diameter of RCA, dominant RCA, and dominant circumflex artery, respectively. RV ischemia was assessed by using pulse-wave tissue Doppler sampling obtained from RV free wall close to the lateral tricuspid annulus at the apical four-chamber view during dobutamine stress echocardiography (DSE). When the mean systolic velocity percentages of increase from low to peak dose dobutamine in patients with small RCA were compared to those of other groups, statistically significant difference was found between group 1 and the other groups (P = 0.007 for group 1 vs group 2; P = 0.01 for group 1 vs group 3). The mean systolic velocity at peak dobutamine dose of patients with small caliber of right coronary artery was statistically lower than the other groups (P = 0.001 for group 1 vs group 2, P < 0.001 group 1 vs group 3). There are a group of patients with small diameter of RCA causing probable ischemia in RV and small caliber of RCA can really matter in these patients.

Coronary Artery Dilatation and Aortic Outflow Tract Enlargement in Children with Unicommissural Aortic Valves

We evaluated the aortic outflow tract (AOT) and coronary artery dimensions in pediatric patients with unicommissural aortic valves. A retrospective review of an echocardiographic database identified 37 patients with unicommissural aortic valves. A total of 115 echocardiograms were reviewed, and the right coronary artery (RCA), left main coronary artery (LM), left anterior descending coronary artery aortic valve annulus, aortic root, sinotubular junction (STJ), and ascending aorta were measured and z scores determined. The aortic stenosis peak gradient and the amount of aortic regurgitation (AR) were also measured. The RCA diameter (z score, 1.85 +/- 1.8, p = 0.03) and LM diameter (z score, 1.74 +/- 1.47, p = 0.04) are significantly dilated, as are all the AOT measurements: aortic annulus (2.02 +/- 1.9, p = 0.02), aortic root (2.25 +/- 1.9, p = 0.02), STJ (2.22 +/- 1.74, p = 0.01), and ascending aorta (4.38 +/- 2.03, p < 0.001). Longitudinal follow-up showed that there was no significant variation over time in any variable. The AOT measurements were significantly correlated with each other. A trend was found in which an increasing amount of AR gave an increase in AOT measurements. The aortic gradient was not significantly associated with any measurement. Our study population demonstrated significant dilatation of the RCA and LM as well as the AOT. The dilatation of the AOT structures is likely caused by the same mechanism that accounts for the AOT dilatation in patients with bicommissural aortic valves. Dilatation of the coronary arteries may represent an intrinsic abnormality in the vessel wall. Further studies are needed to define possible changes.

MORPHOLOGICAL ADAPTATION OF THE CORONARY ARTERIES IN NEONATAL RATS. † 162

Morphological adaptation of the left and right coronary arteries of neonatal rats was studied using the whole body freezing technique. Newborn rats were fixed by using acetone cooled to -80°C by dry ice on 0(n=20), 1(n=13), 2(n=18),4(n=16) days after birth. The thorax of the frozen rat was sectioned on a freezing microtome in the coronal plane. These sections of the heart were photographed and the inner diameters of the two coronary arteries were measured. Biventricular masses were calculated as follows; all the cross-sectional areas of the ventricular muscles multiplied by 0.3 mm(thickness) were summed up. Left ventricular mass increased rapidly after birth (Oday; 7.9±0.2mm3, 1 day; 11.0±0.5mm3, p<0.01, 2 days; 13.8±0.5mm3,p<0.01, 4days; 22.0±0.7mm3,p<0.01). There was no significant change of the diameter of left coronary artery from 0 day after birth (122±4 μ m) to 2days after(128±2 μ m). Since then, it significantly increased(4days; 165±5 μ m, p<0.01). Right ventricular mass increased after birth (0day; 9.1±0.3mm3, 1day; 10.7±1.4 mm3, 2 days; 12.4±2.4mm3, p<0.01, 4days; 18.3±0.8mm3, p<0.01). The diameter of right coronary artery also significantly increased since 2days after birth(0day; 121±4 μ m, 2days; 123±3 μ m, 4days; 137±4 μ m, p<0.01). In neonatal rats right after birth, there were time lags in the morphological adaptation (increase of the diameters) of the coronary arteries to rapid increase of the ventricular masses.

ECHOCARDIOGRAPHIC DIFFERENTIATION BETWEEN ANOMALOUS LEFT CORONARY ARTERY FROM THE PULMONARY TRUNK AND DILATED CARDIOMYOPATHY

Direct visualization of an anomalous left coronary artery from the pulmonary trunk (ALCA) is not always possible by cross-sectional echocardiography (CSE). By contrast, a large right coronary artery (RCA) in ALCA can usually be seen. We reviewed the diagnostic value of the RCA diameter measurement by CSE in the differentiation between ALCA and dilated cardiomyopathy (DCM) of other etiology. In 28 controls, RCA increased with age; RCA(mm) = 0.781 log(months) + 0.639 (r=0.829, SEE=0.306), but RCA/aortic root ratio (RCA/AO) showed no variation with age (11.9±2.0%). Morphometric criteria for ALCA was made as RCA larger than the 95% confidence limit of normal or RCA/AO larger than 17%. Diagnostic criteria of (1) direct visualization of ALCA, (2) diastolic flow in pulmonary artery by Doppler echocardiography and (3) RCA morphometry were assessed in 10 patients with ALCA (3-105 mos; median 8.5 mos) and 11 with DCM (2-113 mos; median 7 mos) by blind observers. RESULT: There were no false positive diagnoses of ALCA. Sensitivity was 40% by (1); 40% by (2); 70% by (3); 60% by (1+2); and 80% by (1+3). Interobserver agreement was assessed in 18 patients and was significantly concordant: r=0.934 for RCA and r=0.905 for RCA/AO. CONCLUSION: Careful visualization and measurement of RCA can accurately confirm a diagnosis of ALCA.