Hydrated silicate minerals on Mars observed by the Mars Reconnaissance Orbiter CRISM instrument.

Phyllosilicates, a class of hydrous mineral first definitively identified on Mars by the OMEGA (Observatoire pour la Mineralogie, L'Eau, les Glaces et l'Activitié) instrument, preserve a record of the interaction of water with rocks on Mars. Global mapping showed that phyllosilicates are widespread but are apparently restricted to ancient terrains and a relatively narrow range of mineralogy (Fe/Mg and Al smectite clays). This was interpreted to indicate that phyllosilicate formation occurred during the Noachian (the earliest geological era of Mars), and that the conditions necessary for phyllosilicate formation (moderate to high pH and high water activity) were specific to surface environments during the earliest era of Mars's history. Here we report results from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) of phyllosilicate-rich regions. We expand the diversity of phyllosilicate mineralogy with the identification of kaolinite, chlorite and illite or muscovite, and a new class of hydrated silicate (hydrated silica). We observe diverse Fe/Mg-OH phyllosilicates and find that smectites such as nontronite and saponite are the most common, but chlorites are also present in some locations. Stratigraphic relationships in the Nili Fossae region show olivine-rich materials overlying phyllosilicate-bearing units, indicating the cessation of aqueous alteration before emplacement of the olivine-bearing unit. Hundreds of detections of Fe/Mg phyllosilicate in rims, ejecta and central peaks of craters in the southern highland Noachian cratered terrain indicate excavation of altered crust from depth. We also find phyllosilicate in sedimentary deposits clearly laid by water. These results point to a rich diversity of Noachian environments conducive to habitability.

Once weekly azithromycin in secondary prevention of rheumatic fever.

Rheumatic fever and rheumatic heart disease (RHD) are still important problems in developing countries. Secondary prophylaxis which is the most cost-effective method in preventing recurrences of rheumatic fever is fraught with problems of drug compliance. The utility of 500 mg once weekly azithromycin (AZT), an orally effective long-acting antibiotic was evaluated against oral penicillin (phenoxy methyl penicillin 250 mg twice daily) in this study. Forty-eight consecutive patients (44% males, mean age 29.4 years) with established RHD were randomised into two groups-26 patients received AZT and 22 received oral penicillin. Patients were evaluated at randomisation, at 1 month, 3 months, and 6 months, clinically, serologically and by throat swab culture. End points were absence of streptococcal colonisation, infection or fever at the end of 6 months. During the study, 4 patients (15.4%) in the AZT group developed sore throat and fever, had positive throat culture and positive serology indicating streptococcal infection. None satisfied the criteria for rheumatic fever reactivation. None in the oral penicillin group developed streptococcal infection. In conclusion, weekly 500 mg of AZT is not effective in the prevention of streptococcal throat infection compared to oral penicillin therapy in adult patients with established RHD.

Left atrial myxoma-influence of tumour size on electrocardiographic findings.

OBJECTIVE: The data of 51 patients (33 females) who underwent excision of left atrial (LA) myxoma were retrospectively reviewed for correlation of tumour size and electrocardiographic (ECG) findings. METHODS AND RESULTS: Mean age was 39.1 ± 15 years (range 9-53 years). The LA enlargement (LAE) on ECG was defined by standard criteria. The LAE in ECG in these patients did not correlate with echocardiographic LA dimensions or with the degree of left ventricular (LV) inflow obstruction. But it was found that the presence of LAE in ECG predicted maximum tumour dimension of >5 cm and correlated with the degree of mitral regurgitation (MR). The LAE in ECG disappeared following surgery in 87.5% of patients. CONCLUSION: The LA enlargement on ECG in a patient with LA myxoma signifies larger tumour size or the presence of significant MR but is not necessarily associated with an increased LA size or LV inflow obstruction.

Prevalence of Schistosomiasis in a neglected community, South western Nigeria at two points in time, spaced three years apart.

BACKGROUND: In recent years, the prevalence of schistosomiasis, a neglected tropical infection, has increased in underprivileged rural communities characterized by poverty. OBJECTIVE: This cross-sectional community-based study was carried out to determine the prevalence of urinary schistosomiasis in a neglected community of Apojola community, South-Western Nigeria at two points in time, spaced three years apart. METHOD AND RESULTS: A total of 145 participants were screened and 44.1% were diagnosed to have urinary Schistosoma haematobium infection after sedimentation and microscopy. The prevalence of schistosomiasis among females was higher (45.3%) than that among males (42.4%) but not significantly different (0.723). The prevalence of participants with light infection (26%) was significantly higher than those with heavy infection (11.0%). The predisposing factors with statistically significant association with Schistosoma haematobium infection were age (0.000), level of education (0.002), eating/selling of snails (0.037), occupation (0.000), drinking water (0.001), swimming (0.008), and washing in a river (0.019). CONCLUSION: These findings indicate that the study area is still endemic to urinary schistosomiasis after three years of research and school-age children and teenagers are the populations at risk of urinary schistosomiasis. Community health education on the cause, mode of transmission, prevention, and prompt treatment of schistosomiasis is recommended.

Association of Pediatric Cardiac Surgical Volume and Mortality After Cardiac ECMO.

Centers with higher surgical and extracorporeal membrane oxygenation (ECMO) volumes have improved survival for children undergoing pediatric cardiac surgery and ECMO, respectively. We examined the relationship between both cardiac surgical and cardiac ECMO volumes, with survival. Using data from the Pediatric Health Information System, we reviewed patients who underwent ECMO during the hospitalization for cardiac surgery or heart transplantation from January 2003 to June 2014. Among 106,967 patients in 43 centers undergoing a Risk Adjustment for Congenital Heart Surgery-1 1-6 procedure (n = 104,951) or cardiac transplantation (n = 2,016), 2.9% (n = 3,069) underwent ECMO support. Centers were categorized into volume quartiles based on annual ECMO and cardiac surgical volumes. Multivariable logistic regression models controlling for clustering by center and adjusting for factors associated with mortality were constructed. Although mortality was lower in ECMO centers that performed ≥7 ECMO runs (odds ratio [OR]: 0.44, 95% confidence interval [CI]: 0.22-0.88)] and centers performing ≥158 cardiac surgical cases (OR: 0.37, 95% CI: 0.22-0.63), surgical volume was more strongly associated with ECMO mortality. Centers with higher cardiac surgical volume had fewer ECMO complications. Cardiac surgical volume, compared with ECMO volume, is more strongly associated with cardiac ECMO survival.

Islet cell transplantation for insulin-dependant diabetes mellitus: perspectives from the present and prospects for the future.

The long-term complications of insulin-dependant diabetes mellitus have become a major health care problem, and it is now clear that they arise from inadequate homeostatic control of blood glucose by injected replacement insulin. Transplantation of pancreatic islets is arguably the most logical approach to restoring metabolic homeostasis in people with diabetes. This review looks at the current status of human islet transplantation and the problems that remain. These include: (1) the limited supply of human islet tissue available for transplantation; (2) the adverse effects of current immunosuppressive protocols on diabetic patients; (3) the problems of primary nonfunction of the transplanted islets; (4) the rejection of islets; and (5) the recurrence of autoimmune diabetic disease. Some of the approaches that might solve these problems are then examined: (1) immune modulation to reduce or prevent immune attack by the recipient's immune system; (2) immunoisolation to prevent recognition of the islet graft; (3) induction of tolerance; (4) xenotransplantation using islets derived from animals; and (5) gene therapy.

Comparison of percutaneous transmitral commissurotomy with Inoue balloon technique and metallic commissurotomy: immediate and short-term follow-up results of a randomized study.

BACKGROUND: The Inoue balloon technique for mitral commissurotomy is well established and carried out worldwide. Metallic commissurotomy is reported to be a cheaper and effective alternative to balloon mitral commissurotomy. METHODS: One hundred patients were randomized into 2 groups to undergo percutaneous transmitral commissurotomy (PTMC) by means of the Inoue balloon technique (IBMC, n = 49) or metallic commissurotomy (PMMC, n = 51). Patients were crossed over to the other technique when the initial technique was a failure. Success of valvotomy, procedure-related complications, and follow-up events of the 2 techniques were compared. RESULTS: Basal echocardiographic and hemodynamic data were similar in both groups. Procedural success was similar in both groups: 45 of 49 procedures (91.8%) in the IBMC group, compared with 46 of 51 procedures (90.18%) in the PMMC group (P = 1.0). Crossover was also comparable, with 1 occurring in the IBMC group, compared with 3 in the PMMC group. Complications such as cardiac tamponade and mitral regurgitation (requiring or not requiring mitral valve replacement) were similar in both groups, with 3 complications in the IBMC group, compared with 4 complications in the PMMC group (P =.29). After a follow-up period of approximately 4 months, both groups had similar event rates and comparable hemodynamic parameters (P = not significant). CONCLUSIONS: Both IBMC and PMMC are successful means of providing relief from severe mitral stenosis with a gain in valve area and reduction in transmitral gradient. Both techniques have similar procedural success, complication rates, and follow-up events.

Transplantation of mouse pancreatic islets into primates--in vivo and in vitro evaluation.

BACKGROUND: Islets transplanted from other species to man has the potential to cure diabetes but whether islets are subject to hyperacute rejection after xenotransplantation is contentious. We transplanted mouse pancreatic islets of mouse beneath the primate renal capsule and assessed natural xenoantibody binding, complement activation and cell lysis in vitro. METHODS: Freshly isolated mouse islets were transplanted in a blood clot under the renal capsule of cynolmogus monkeys. The graft was removed after 24 hr for histological and ultrastructural analysis. Freshly isolated mouse pancreatic islets were analyzed in vitro by immunohistochemistry for Gal(alpha1,3)Gal and Von Willebrand factor expression and for IgG, IgM, C3, C4, and C5b-9 binding after incubation in 100% human serum. Complement mediated cell lysis was evaluated by 51Cr release assays after incubation of islets for 4 hr in human serum, plasma, and lymph with and without added neutrophils. RESULTS: Mouse islets transplanted under the renal capsule of cynomolgus monkeys were destroyed within 24 hr by a process involving necrosis with neutrophil and mononuclear cell infiltration. Gal(alpha1,3)Gal was strongly positive on only 10% of islet cells. After islet incubation in 100% human serum before frozen section, human IgG and IgM, C3, C4, and C5b-9 was deposited on islets with increased intensity in the periphery. Measurement of 51Cr release from labeled fresh islets after four hours incubation in 100% human serum showed 17% lysis and was not changed by addition of neutrophils. CONCLUSION: These results indicate that mouse islets in a primate recipient undergo rapid destruction by a process that has features similar to hyperacute rejection in vascularized organs and we propose the same term be used.

Percutaneous coil closure of recanalised anomalous origin of left coronary artery from pulmonary artery.

An asymptomatic boy underwent surgical correction of anomalous origin of left coronary artery from pulmonary artery (ALCAPA) with trans-pulmonary artery interruption and saphenous vein grafting to left anterior descending coronary artery. He developed a shunt through the re-canalised pulmonary artery end of the ALCAPA which was successfully embolised using a detachable PDA coil delivered into the left main coronary artery from the pulmonary artery.

Central pulmonary artery anatomy in right ventricular outflow tract obstructions.

We reviewed the cine-angiograms of 190 patients with right ventricular outflow tract (RVOT) obstructions for size and anatomy of pulmonary arteries, patent ductus arteriosus (PDA) and major aorto pulmonary collateral arteries (MAPCAs). Patients were grouped into three, Tetralogy of Fallot (TOF) with pulmonary atresia (group 1, N=86), TOF with pulmonary stenosis (group 2, N=97) and 7 cases of pulmonary atresia with intact interventricular septum (group 3). Out of 86 patients in group 1, 49 had PDA alone, 30 had MAPCAs alone, six had both and one had none. In group 2, 31 patients had persistent PDA and one patient had MAPCAS and PDA. A discrete stenosis (DS) of pulmonary artery was seen significantly more in patients with RVOT obstructions associated with PDA compared to patients without PDA (67/84 vs. 5/96). Out of the 84 cases with ducti, 53 had stenosis of the pulmonary artery at the site of ductus insertion. Thus presence of PDA was an important factor in the development of DS. The likely cause of pulmonary artery stenosis in TOF with PDA may be the opposing flows through RVOT and PDA producing a watershed effect at the ductus-pulmonary artery junction. Diffuse hypoplasia of pulmonary arteries (DH) was seen more significantly in RVOT obstructions associated with MAPCAs, compared to other patient groups (19/36 vs. 14/87). These small pulmonary arteries had no discrete stenosis and this diffuse hypoplasia might be the result of inadequate blood flow during intrauterine life [Harikrishnan S, Tharakan J, Titus T, Bhat A, Sivasankaran S, Bimal F, Syam Sunder KR, James, KJ. Central pulmonary artery anatomy in right ventricular outflow tract obstructions. Indian Heart Journal 1997;49:624 (Abstract)[18]].

Clinical profile and natural history of Ebstein's anomaly of tricuspid valve.

There were 63 patients of Ebstein's anomaly of tricuspid valve encountered from 1976 to 1991; 28 (44.4%) were male and 35 (55.6%) female. Their age at presentation ranged from 3 months to 51 years. Five (7.9%) patients were asymptomatic, 48 (76.2%) had class II-III exertional dyspnoea, palpitation or both. Thirty patients (47.6%) had cyanosis. Electrocardiogram showed paroxysmal atrial fibrillation in two, chronic atrial fibrillation in four (6.3%), paroxysmal supraventricular tachycardia in seven, atrial or ventricular ectopic beats in five (7.9%), 2:1 atrioventricular block in one (1.6%), complete atrioventricular block in two (3.2%) and type B WPW syndrome in nine patients (14.3%). Chest X-ray showed diminished vascularity in 22 (34.9%). Diagnosis was established by cardiac catheterization and or echocardiography. Atrialized right ventricular chamber was demonstrated in 51 (80.9%) by angiography and in 40 (63.5%) by electrophysiology. Patients were followed up for 1-172 months. Seventeen patients (26.9%) required surgery. Three patients (4.8%) died during medical follow-up, and five (7.9%) died following surgery. Survival probability for 46 medical patients was 88.9% at 172 months. Factors affecting survival were pulmonary blood flow, cyanosis, clubbing and systemic arterial oxygen saturation.

Prognosis for patients with Eisenmenger syndrome of various aetiology.

The objective of this study was to determine the long-term survival pattern and variables affecting long-term survival and complications occurring during follow-up of patients with Eisenmenger syndrome. A retrospective study of patients diagnosed with Eisenmenger syndrome were followed up. A tertiary care centre was used and it provided superspeciality services in various disciplines. The subjects included 201 patients with Eisenmenger syndrome--diagnosed by a combination of echocardiography and a peripheral arterial oxygen saturation study and/or cardiac catheterisation with or without angiocardiography--worked up and followed up for variable duration over a period of 16 years from 1976 to 1992. One hundred nine patients were females and 92 were males--age of presentation varied from 3 months to 62 years (mean +/- standard deviation 19.23 +/- 12.62 years). A total of 12 different anatomic lesions were seen--the most common three being ventricular septal defect (33.33%), aterial septal defect (29.85%), and patent ductus arteriosus (14.23%). History, physical examination, chest skiagram and electrocardiogram established only the presence of pulmonary arterial hypertension except where differential cyanosis indicating ductus was discernible or the degree of splitting of second heart sound provided some clue to the level of shunt. Contrast echocardiography, completed in 25.4% established the level of shunt in all patients. In others the diagnosis was confirmed by cardiac catheterisation. Twenty patients died during a mean follow-up period of 54.6 +/- 54.47 months. Sudden cardiac deaths (30%), congestive heart failure (25%) and haemoptysis (15%) were the most predominant causes of death. Only one patient died during puerperium.(ABSTRACT TRUNCATED AT 250 WORDS)

Balloon pulmonary valvoplasty: factors determining short- and long-term results.

Balloon pulmonary valvoplasty was performed in 139 patients (age 2-44 years) with pulmonary valve stenosis. The right ventricular peak systolic pressure decreased from 137.1 +/- 46.8 mmHg to 76 +/- 51.3 mmHg (P < 0.001) and the right ventricle to pulmonary artery peak systolic gradient decreased from 116.3 +/- 49 mmHg to 54.4 +/- 51.9 mmHg (p < 0.001). There was no significant change in systemic artery systolic pressure. The right ventricular peak systolic pressure to systemic artery systolic pressure ratio decreased from 1.13 +/- 0.41 to 0.63 +/- 0.42 (P < 0.001). Patients with incomplete immediate relief of obstruction (right ventricle to pulmonary artery peak systolic gradient > 35 mmHg) had higher pre-dilatation right ventricular peak systolic pressure (161.1 +/- 45.3 mmHg vs. 93.9 +/- 38.8 mmHg, P < 0.001) and higher right ventricular peak systolic pressure to systemic artery systolic pressure ratio (1.31 +/- 0.42 vs 0.98 +/- 0.33, P < 0.001) pre-dilatation and were older (17.2 +/- 8.6 years vs. 12.8 +/- 9.7 years, P < 0.01). The residual right ventricle to pulmonary artery peak systolic gradients in the majority of patients were infundibular, which regressed at follow up even in patients who did not receive long-term oral beta blockers. Follow up catheterisation in 79 patients after 13 +/- 8.7 months showed a further fall in right ventricular peak systolic-pressure (P < 0.001) and right ventricle-to-pulmonary artery peak systolic gradient (P < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Percutaneous transvenous mitral commissurotomy using an Inoue balloon in children with rheumatic mitral stenosis.

Percutaneous transvenous mitral commissurotomy (PTMC) using the Inoue technique was performed in 557 patients with rheumatic mitral stenosis. Of these, 107 were children aged 10-18 years (mean +/- SD 14.5 +/- 2.3). All patients were symptomatic New York Heart Association (NYHA) Class II (n = 78) and Class III (n = 29). All were in sinus rhythm. Following PTMC, the mitral valve area (MVA) increased from 0.73 +/- 0.18 to 1.7 +/- 0.53 cm2 (P < 0.001). There was a significant fall in mean transmitral gradient from 15.6 +/- 5.2 to 5.1 +/- 2.3 mmHg, and in mean pulmonary artery pressure from 41 +/- 15 to 28.4 +/- 10 (P < 0.001). Cardiac tamponade developed in one patient. One patient developed severe mitral regurgitation requiring emergency mitral valve replacement. Five patients (4.7%) developed moderate mitral regurgitation. There was no mortality or cerebral embolism in any of the children. Four patients (3.7%) had oximetry evidence of atrial septal defect. Mean mitral valve area and transmitral gradient at 14 months mean follow up was 1.68 +/- 0.4 cm2 and 6 +/- 3.5 mmHg, respectively, and were comparable to the immediate post-PTMC results. Two patients (1.8%) developed restenosis. The immediate haemodynamic results in children were compared to 450 adult patients who underwent PTMC in the same period. The outcome was similar in both groups. Children were found to have significantly higher pulmonary artery pressure compared to adults. We found that PTMC using an Inoue balloon is very effective and safe in children, and consider that it should be the procedure of choice for young patients with symptomatic rheumatic mitral stenosis.

Balloon angioplasty for native coarctation of the aorta in children and adults: factors determining the outcome.

Balloon angioplasty was performed in 46 patients (age 2-40 yr) with discrete native coarctation of aorta. Patients with associated patent ductus arteriosus, aberrant subclavian artery and aneurysms were excluded. The peak systolic gradient across the coarcted segment decreased from 52.1 +/- 18.5 mmHg to 18.6 +/- 14.8 mmHg (p less than 0.001), and the diameter of the coarcted segment increased from 3.6 +/- 1.7 mm/m2 to 9.1 +/- 3.2 mm/m2 (p less than 0.001). Follow-up haemodynamic and angiographic studies performed in 21 patients at 13.1 +/- 6.9 months after angioplasty, showed good results in 15 patients. Four patients undergoing haemodynamic study and 4 other patients undergoing noninvasive evaluation were graded as having bad results at follow-up. In 5 of these patients the poor results were due to primary failure of angioplasty in relieving the gradient, and three developed re-coarctation after initial fall in the trans-coarctation gradient. Four risk factors were identified on univariate analysis, which were associated with significantly larger residual gradients at follow-up: (1) size of isthmus/size of coarcted segment ratio less than 3.0; (2) size of post-coarctation descending aorta/size of isthmus ratio greater than 1.75; (3) size of coarcted segment after angioplasty/size of coarcted segment before angioplasty ratio less than 2.0; and (4) size of balloon/size of coarcted segment ratio less than 3.0. The presence of one or more risk factors was associated with bad late results. On multivariate analysis the ratio of balloon size/coarcted segment size was found to be the sole independent predictor of the late outcome (p less than 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary artery fistula in children and adults: a review of 25 cases with long-term observations.

We studied 25 patients with coronary artery fistula between 1976 and 1994. Age ranged from 1 to 58 years. Twelve patients were symptomatic; seven had dyspnoea, four had angina, one had palpitation and one had syncope. Coronary arteries in four. Coronary artery fistula drained into right ventricle in 11, right atrium in nine, pulmonary artery in four and left ventricle in two. The Qp/Qs ranged from 1.0 to 2.6 with a mean of 1.39 +/- 0.38. Five patients had associated cardiac anomalies. Two had atrial septal defects, one had patent ductus arteriosus, one had atresia of proximal right coronary artery and in one patient, the right coronary was arising from left coronary artery. Five patients underwent surgery without any operative mortality. Thirteen patients were followed-up medically for a mean period of 6.1 +/- 5.1 years. There were no complications related to coronary artery fistula during follow-up. In one patient coronary artery fistula closed spontaneously.

Development of a novel digestion chamber for human and porcine islet isolation.

BACKGROUND: The current technique of human pancreas digestion for islet isolation relies on selective distribution of collagenase delivered via the pancreatic duct to produce digestion and removal of peri-acinar fibrous tissue. However, the collagenase has relatively little effect on the interlobular fibrous tissue, which must therefore be broken down by mechanical means within the digestion chamber so as to release the contained acini and islets. The current way of achieving this in the Ricordi chamber is to place five or six stainless steel balls within the chamber and shake vigorously. The shaking presumably breaks down the interlobular fibrous tissue by a combination of shear force induced by the movement of tissue through the shaking process, assisted by numerous blows from the steel balls. Intuitively, one would expect some islets would be destroyed rather than released by such a battering. METHODS: In an attempt to improve the efficiency of islet isolation we have designed a new digestion/filtration chamber that consists of a glass cylinder, sealed with Teflon plates holding in mesh filters at each end, secured in place by a central threaded tie-rod and external knurled nuts. A ring-shaped piston within the cylinder can be pushed up and down the travel by two rods passing out through sealed ports in the Teflon disk at one end and connected to an external handle. The handle is used to gently push the piston up and down the travel of the cylinder, which pushes the fluid and tissue through the central lumen of the ring-piston. A series of hooks attached to the central tie-rod catch the fibrous strands of the passing tissue; the shearing forces produced cause disruption by a process thought to be similar to teasing the tissue apart with fine forceps. RESULTS: A series of initial experiments with human pancreas showed the prototype to be too large, causing temperature control problems, and a redesigned smaller chamber was produced, maintaining the crucial design features. Experience processing five human pancreata has now demonstrated that in three of five pancreata the new chamber produced a good yield (>200,000 I.E.) of remarkably well separated and intact islets, the entire dispersion process being under 1 hour. However, in two isolations the collagenase digestion was poor, with few free islets. A copy of the new chamber (reserved for porcine work only) has been produced, as well as a copy of the Ricordi chamber. We have confirmed that the new chamber can isolate porcine islets in large numbers (>5000 islets/g pancreas [n = 2], but note that pig islets are small). CONCLUSION: These preliminary studies are sufficiently encouraging to justify further direct comparison with the Ricordi chamber for the purpose of animal and human islet isolation.

Bidirectional Glenn shunt: a step in the right direction.

Bidirectional Glenn (BDG) shunt was carried out in 14 patients (age range 1.5-22 years; mean 9.3 years) for a variety of congenital cyanotic heart diseases with decreased pulmonary blood flow. Postoperative cardiac catheterisation was carried out in 10 patients including successful balloon angioplasty of the shunt and LPA in one patient. There was a significant improvement in oxygen saturation and a drop in haematocrit level at follow-up. Doppler echocardiography studies in 13 patients revealed functioning shunts in all cases with low velocity continuous flow. Thus BDG is a useful palliative procedure and could be undertaken as the first stage of total cavopulmonary connection in high-risk Fontan groups where biventricular repair is not feasible.

Coronary artery ectasia: angiographic, clinical profile and follow-up.

Out of 3200 coronary angiograms we reviewed, there were 144 cases of coronary ectasia--an incidence of 4.5 percent. Among these, 122 were associated with atherosclerotic coronary artery disease, i.e. coronary stenosis more than 50 percent (group A) and 22 not associated with coronary artery disease (group B). The patients in groups A and B were compared with age- and sex-matched patients (group C) (n=100) who had coronary artery disease alone without ectasia. The incidence of ectasia was not increased in patients with thoracoabdominal aortic aneurysm i.e. 2/154 (1.8%) or in patients with peripheral occlusive vascular disease i.e. 5/161 (3.1%). Ectasia was typed according to a modified version of the criteria proposed by Markis et al. Type II was the commonest, followed by type I, III and IV. Right coronary artery was the most commonly involved vessel by ectasia followed by left circumflex, left anterior descending artery and left main coronary artery. Diffuse ectasia was seen more frequently in right coronary artery and localised ectasia in left anterior descending artery. Patients in groups A and B had similar epidemiological characteristics, though more patients with ectasia alone (group B) had better left ventricular function and negative stress tests. The patients in group A had a similar incidence of previous myocardial infarction, coronary risk factor profile, treadmill exercise test status and severity of coronary artery disease when compared to group C. On a mean follow-up of 3+/-1.2 years, all the three groups had similar event rates.

Clinical and angiographic profile and follow-up of myocardial bridges: a study of 21 cases.

Myocardial bridging describes an angiographic entity, which is any degree of systolic narrowing of a coronary artery observed in at least one angiographic projection. Among the cineangiograms of 3200 patients reviewed, there were 21 cases (19 males) of myocardial bridges--incidence of 0.6 percent. Of these, seven had hypertrophic cardiomyopathy, six had atherosclerotic coronary artery disease and remaining eight had no evidence of either. All 21 patients had myocardial bridges in proximal or mid left anterior descending coronary artery. In addition, one case of hypertrophic cardiomyopathy had whole posterior descending coronary artery under a myocardial bridge. Another case of hypertrophic cardiomyopathy had a short normal segment of 5 mm inside a long myocardial bridge of 35 mm (tandem myocardial bridges). The length of the bridges varied from 10 to 35 mm (mean 24.5 +/- 4.5 mm) and diameter stenosis during systole varied from 40-90 percent (mean 70 +/- 8%). Two patients had large saccular coronary aneurysms proximal to the muscle bridge. Four of the eight patients who had neither hypertrophic cardiomyopathy nor coronary artery disease presented with acute anterior wall myocardial infarction and three of them had regional wall motion abnormality of left descending territory. Of the six patients who had coronary artery disease, one had 60 percent left descending artery lesion and two had recanalized segments proximal to the bridge. Five of the above six patients had significant stenosis of other coronary vessels. Four patients were lost to follow-up (mean period 3.4 +/- 2 years). In the coronary artery disease group, one patient underwent coronary artery bypass graft surgery for 3-vessel disease including graft to left descending artery and one developed inferior wall myocardial infarction. The patients in the hypertrophic cardiomyopathy group and "no hypertrophic cardiomyopathy-no coronary artery disease" group were free of events at last follow-up. Long-term prognosis of isolated myocardial bridges appears to be excellent. Degree of systolic narrowing or length of myocardial bridge does not correlate with event rates on follow-up.