[Mechanical mitral valve prosthesis dysfunction in pregnant women. Report of 2 cases]. / Disfunción de prótesis mitral mecánica en embarazadas. Informe de dos casos.

We present two cases of pregnant women associated with mechanical mitral valve prostheses dysfunction, treated between October 1998 and September 2000, in congestive heart failure, functional class III, without fetal distress. Emergency surgery consisted in cesarean procedure immediately followed for mitral prostheses removal and implantation of new mechanical heart valve prostheses was realized in both patients. In each case a single live infant was obtained with good Apgar evaluation. Both patients had successful surgical procedures. In both patients were found thrombi in the mechanical heart valves. Actually patients and their children have good evolution, without any problem.

[Myxoma of the left auricle and ischemic cardiopathy. Report of a case]. / Mixoma de aurícula izquierda y cardiopatía isquémica. Informe de un caso.

Myxoma is most frequent tumor of the heart, and usually appears isolated. This case involves a 64-year-old female with left atrial myxoma and associated ischemic heart disease. The patient was surgically treated with excision of the myxoma and coronary artery bypass grafting with internal mammary artery to left anterior descending artery. There were no perioperative complications, and the patient is asymptomatic at present. In conclusion, when there exists evidence of associated pathology to a cardiac myxoma, the case must be integrally evaluated in order to effect a complete treatment.

[Preliminary pilot study in humans with coronary endovascular prosthesis (stent SAQ). Immediate and medium-term results]. / Estudio piloto preliminar en humanos con la prótesis endovascular coronaria (stent SAQ). Resultados inmediatos y a mediano plazo.

We report the results obtained of 23 patients in whom 25 intracoronary stents (SAQ) were placed. All had atherosclerotic coronary artery disease with different clinical types of presentation, such as stable angina, unstable angina, myocardial infarction. In others cases the reason for the procedure was postangioplasty complications. The majority of cases had complex lesions: total occlusion, long plaques and patients in critical and unstable state. The immediate results were considered satisfactory due to the fact that there was angiographic improvement compared to just conventional angioplasty, the final flow was TIMI-3 in 23 and TIMI-2 en two others, in these cases the initial flow was TIMI-0. The arterial diameter improved compared to prior angioplasty. Acute thrombosis occurred in one case and was resolved with repeated dilatation, in two cases the atherosclerotic plaque protruded within the stent, in both cases the occlusion was considered non significant, without modifications in the flow. All patients had a 3 months follow up with treadmill test. In 10 cases angiography was indicated, in 4 due to positive treadmill. Restenosis was resolved in three cases, in another coronary arterial by-pass was necessary. In all other cases angiographic findings were normal, included one patient with two stents.

[De novo neoplasms in transplant patients]. / Neoplasias de novo en pacientes trasplantados.

To identify the number of patients with de novo tumors in organ transplant recipients, we collected the information from eleven hospitals of the Instituto Mexicano del Seguro Social with organ transplant programs. During a period of 9 years, we found only five cases of neoplasia. The median age was 26 years. All tumor occurred in renal transplant recipients. All patients received cyclosporine, azathioprine and steroids. One breast tumor, one renal carcinoma, two Kaposi's sarcoma and one angioleiomyosarcoma were found. The frequency of tumors in these patients is lower than reported by other authors, probably due, in our series to the fact that the patients were younger and the existence of a recently created transplant program with a short period of follow-up.

[Rheumatic cardiopathy and Chagas disease]. / Cardiopatía reumática y enfermedad de Chagas.

Rheumatic heart disease is common in the undeveloped world; Chagas disease, a typical rural parasitic condition started to affect urban areas. Both have a relatively high incidence and prevalence in Latin America, however, we could not find a report of patients with coincidental rheumatic heart disease and Chagas disease. Herein we report the first documented case.

[Effects of bezafibrate in the diet of hypertensive patients with dyslipidemia and hyperfibrinogenemia]. / Efecto de bezafibrato en la dieta de hipertensos con dislipidemia e hiperfibrinogenemia.

OBJECTIVE: To evaluate the fibrinogen and lipids response to diet plus bezafibrate in insulin-resistant patients with arterial hypertension and mixed hyperlipidemia. METHODS: A randomized double blind parallel design was used during a 90 days treatment period. Fibrinogen, lipids, insulin and peptide C assays as well as a glucose tolerance test were done at the start and end of treatment. The 28 patients received a hypolipemic diet low in refined sugars with bezafibrate added (400 mg/day) in 15 and a placebo in 13. RESULTS: The groups were similar in age, blood pressure and BMI. At the end of treatment, fibrinogen, cholesterol, triglycerides and LDL-C were lower in both groups as compared to the initial values, but only in the bezafibrate group there were: a) significant decrease in triglycerides (64 mg/dL, p 0.01); and b) marginal changes in fibrinogen (decreased 35 mg/dL, p = 0.09), total cholesterol (decreased 26 mg/dL, p = 0.10) and glucose/insulin ratio (increased from 4.4 to 5.2, p = 0.09). Bezafibrate lowered slightly the insulin level but did not affect peptide C. A correlation of changes in fibrinogen levels and the 60 min insulin concentration in the glucose tolerance test was higher in the bezafibrate group (r = 0.61) than in the placebo group (r = 0.23). CONCLUSIONS: In insulin resistant patients with high cardiovascular risk, bezafibrate and a placebo added to a hypolipemic diet decreased plasma fibrinogen. Bezafibrate lowered significantly the levels of triglycerides in these patients.

[Design and development of a stent (SAQ) for the treatment of arterial coronary arterioscleotic obstruction]. / Desarrollo y diseño de un stent (SAQ) para el tratamiento de obstrucciones arteriales aterosclerosas coronarias.

The practice of percutaneous transluminal coronary angioplasty has shown that the major complications are acute dissection as well as suboptimal results and restenosis. The effort to reduce these complications has led to create an intravascular device called Stent. The technology is complex and very expensive, for this reason we designed and made a new model of stent named SAQ. We introduce: The methodology of development, fabrication and modifications of a new intravascular device Stent SAQ. The results obtained in coronary arteries of ex vivo hearts of pigs and humans. The results in two model of animals, rabbit aorta and peripheral arteries in dogs. This investigation at this phase, shows satisfactory properties of SAQ which is secure and effective, with similar properties to the stents in use.

[Stents: experience at the Cardiology Hospital of the 21st century National Medical Center]. / Stents: Experiencia en el Hospital de Cardiología del Centro Médico Nacional Siglo XXI.

UNLABELLED: From february 1995 to february 1997 we implanted 157 stents in 105 patients. Age ranged from 38 to 81 years (mean 58), there were 83 males and 22 females. In 62.8% cases we implanted one stent and in 39 (37.2%) cases 2 to 6. Eighty three were Palmaz/Schatz (P/S), 27 ACT-ONE, 18 Wiktor (W), 9 Gianturco Rubin (GR), 8 Wallstent, 6 XT-Bard and 6 microstent. Indication were de novo in 23.8%, 87.5% post failure PTCA and in 13.3% late PTCA restenosis. Implant was successful al 96.1% of the patients. The first 32 patients received oral anticoagulation, the last 72 received aspirin and ticlopidine only. COMPLICATIONS: 4.7% acute thrombosis, 0.9% sub-acute thrombosis, three of them (2.5%) developed myocardial infarction, 0.9% emergency surgical treatment, 2.8% vascular complications and death in 2.8%. During follow-up (1 to 18 months, mean 7.7) we repeated angiography and 35 patients two to 14 months (m = 5.6), 12 of them had restenosis, during dilation two cases had dissection of the main left coronary artery and were send to surgery, the others were dilated without complications. One case had restenosis of the stent with obstructive lesions in other vessels and was send to elective surgery. The reminded patients are symptom free and had negative stress test. We conclude that this technology is an excellent alternative to percutaneous myocardial revascularization. Larger trials with long term follow-up is necessary to determine the true incidence of restenosis with the different types of stents.

[Thrombosis of mechanical heart valve prosthesis. Predisposing factors and results of surgical treatment]. / Trombosis de las prótesis valvulares cardíacas mecánicas. Factores predisponentes y resultados del tratamiento quirúrgico.

Heart valve thrombosis is a serious complication. From February, 1995 to January, 1996, 19 patients were studied to identify predisposing factors and results of surgical management. Mean age was 47.3 years. Thirteen patients (73.6%) had an irregular surveillance of anticoagulation therapy. Fifteen patients showed low anticoagulation effect during their evolution. Sixteen patients were in functional class III and 80% (15 patients) showed imaging of thrombus in the echocardiographic study. All patients presented thrombus on both sides of the prothesis. There were no deaths, and 15 patients returned to functional class I. It was concluded that the main predisposing factor in this series of patients was deficient anticoagulation therapy, and surgical results are comparable to those other authors.

[Usefulness of intracoronary ultrasound in percutaneous transluminal coronary angioplasty]. / Utilidad del ultrasonido intracoronario en la angioplastía coronaria transluminal percutánea.

UNLABELLED: From February 1995 to April 1996 we performed intracoronary ultrasound (ICUS) in 32 patients who had percutaneous transluminal coronary angioplasty (PTCA). Eccentric plaques were found in 53% (n = 17) and concentric in 47% (n = 15). We found that 59.3% (n = 19) were soft, hard 21.8% (n = 7) and calcified plaques in 19% (n = 6). More than 40% of the plaques had some degree of calcium and most of them had dissection post PTCA ICUS deferred the procedure in 25% (n = 8) of cases. Seven of them were patients with late control post PTCA and no significant obstruction and a patient was found not to be a good candidate for PTCA. In 24 lesions we found morphology changes post PTCA: 41.6% type A, 12.5% type B, 45.8% type C, 8.3% type D, 90.9% type E1 and 9.1% type E2. Dissection was present in 54.1% post PTCA, ICUS information indicated other interventions (prolonged insufflations or stents). Two cases with acute coronary syndromes had smooth and fibrous plaques with excellent response to PTCA. Residual percentage stenosis post PTCA for quantitative coronary angiography was 23.7% and with ICUS 52.4%. COMPLICATIONS: there were three cases with coronary spasm that responded well to nitroglycerin. In conclusion, ICUS provides information to evaluate results of PTCA. It also identifies complications and in some cases can improve results.

[Transcatheter closure of ductus arteriosus with coils. Immediate results. Initial experience in Mexico]. / Cierre transcateterismo del conducto arterioso mediante espirales (coils). Resultados inmediatos. Experiencia inicial en México.

From March to May 1996 we performed transcatheter closure of patent ductus arteriosus with spring coils in 4 patients. Age ranged from 5 month to 11 years (mean 4.3 years). One of them had two previous Rashkind occluders with persistant shunt and other case had pulmonary valve stenosis, in this case we performed pulmonary valvuloplasty and after that closure of ductus arteriosus. Mean pulmonary arterial pressure was 10 to 38 mmHg (mean 18), QP/QS was 1.2 to 5.0 (mean 3.2). Immediate total occlusion occurred in two cases and the other had trivial shunt by doppler echocardiography. No complications were detected. In conclusion we believe that this device is another no surgical alternative to treat persistant ductus arteriosus. It is effective, it has a low cost, and all the patients are candidates. The procedure carries minimum risk and has no mortality.

[Intravascular ultrasound. Initial experience and review of the literature]. / Ultrasonido intravascular. Experiencia inicial y revisión de la literatura.

UNLABELLED: From February 1995 to February 1996, 52 patients underwent intravascular ultrasound (IVUS) imaging: three with aortic coarctation (AoCo), one with persistent ductus arteriosus (PDA), 5 with rheumatic heart disease (RHD) and normal coronary arteries by angiography, one with muscular bridge in anterior descending artery, 20 with percutaneous transluminal coronary angioplasty PTCA (Group I), one of them with eximer laser and 22 stents (Group II). In patients with AoCo was possible to observe obstruction mechanism and the effect of dilation. In patient with PDA we measured the diameter of ductus. In patients with RHD we found early atherosclerosis in four cases, no detected by angiography. In Group I, we found soft plaque in 8, fibrous/mixed in 7 and calcified plaque with the calcium located superficially near the lumen in 5, concentric in 6 and 14 eccentric plaques. In this group the objective was observational in most of the cases, except when the imaging was characteristic of mayor dissection or small final lumen. In 10 cases we observed fracture or dissection of the plaque, in some with small flaps into the lumen. In the last two cases, IVUS was used to optimize results after PTCA in one, in the other we postponed the procedure because the characteristics of the lesion (severe superficial calcification). The patient who underwent eximer laser, IVUS demonstrated irregular and small lumen and was followed by PTCA. In Group II, IVUS was used to optimize deployment of stents. We did not have any case with subacute thrombosis. COMPLICATIONS: Only four cases had angina with ischemic ECG changes during the procedure, but reverted after catheter pullback and intracoronary nitroglycerin. In summary, IVUS gives information about mechanism of obstruction, its complications and results of PTCA. Also detect early atherosclerotic disease not observed by angiography. Optimize deployment of stents and avoids cumarinic anticoagulation in most of the patients. Rational selection of device or deferral of the procedure is possible if we know the characteristics of the plaque before intervention. Utility in other cardiovascular diseases is limited at this time. It's a safe procedure, the morbidity is low and in our experience, without mortality. In the future this new technology will bring useful information in other types of coronary arteries diseases.

[Tutorial training in cardiology and cardiothoracic surgery. Preliminary report]. / Enseñanza tutelar en cardiología y cirugía cardiotorácica. Informe preliminar.

INTRODUCTION AND OBJECTIVES: Personal contact has been lost in medical training due to the increase in numbers of medical students but not of teachers. This fact has impaired training in medical specialties. This is the reason that the Hospital for Cardiology has developed a program of tutelary training. In this paper we present our initial evaluation of this program. METHODS: The inclusive criteria for tutors and students have been defined as have the procedures to develop the program. After three months, 20 residents involved in the tutelary training program were randomly analyzed. Academic activities, clinical practice, research activities and extra-academic activities were evaluated. RESULTS: Currently there are 14 tutors. 50% of residents have developed research projects, 60% has increased academic activities, 50% has improved clinical practice and 65% has defined their postgraduate research projects. CONCLUSIONS: It was concluded that tutelary training in Cardiology and Cardiothoracic Surgery is a useful alternative to improve quality of graduates in these specialties.

[Transcatheter closure of patent ductus arteriosus with Rashkind's occluder. Experience during 3.7 years]. / Cierre transcateterismo del conducto arterioso (CTCA) con oclusor de Rashkind. Experiencia de 3.7 años.

Thirty eight transcatheter umbrella closure (TUC) of a persistently patent ductus arteriosus using the Rashkind umbrella occluder (USCI), were attempted in thirty four patients. Mean age 8.5 +/- 9.0 years (range 1.5 to 31). Internal diameter of ductus arteriosus (DA) average 4.0 +/- 1.5 mm (range 2 to 9 mm). Successful implantation was achieved in 36 procedures (94.7%). Complete closure immediately postimplantation was achieved in 15 (45.4%), 12 (36.3%) had trivial and 6 (18.1%) severe residual shunt. In four cases we implanted successfully a second device. At the follow-up (average 24 months) in 31 patients, 87.0% (n = 27) had complete closure and 96.7% (n = 30) did not need another intervention. Device embolization to distal left pulmonary artery occurred in two cases (5.2%), one was retrieved by surgery and in the other case it was allowed to remain. No mortality was observed. This results confirm the efficacy, with low morbidity and no mortality of TUC, especially in those with smaller PDA (< 4 mm).

[Percutaneous mitral commissurotomy with an Inoue catheter in congenital mitral stenosis]. / Comisurotomía mitral percutánea con catéter de Inoue en estenosis mitral congénita.

We describe a 3-years-old boy, with congenital mitral stenosis, who underwent percutaneous transvenous mitral commissurotomy (PTMC) with Inoue balloon. The mitral gradient decreased from 24 to 4 mmHg, the mitral valvular area (MVA) increased from 1.2 to 1.6 cm2 without modification in mitral regurgitation. One year later the recatheterization showed decreased pulmonary pressures, and a 7.5 mmHg mitral valvular gradient without mitral insufficiency. MVA by echo is 1.8 cm2 with mild regurgitation. As far as we know there is no experience with Inoue balloon in children. We conclude that PTMC with Inoue balloon could be an attractive alternative in some patients with congenital mitral stenosis.

[Residual shunts after application of the Rushkind occlusion system in closure of persistent ductus arteriosus. Insertion of a second device]. / Fuga residual postcolocación de oclusor de Rashkind para cierre del conducto arterioso persistente via percutánea. Colocación de un segundo dispositivo.

From May 1991 to August 1994, we performed transcatheter closure of patent ductus arteriosus with Rashkind umbrella system in 25 patients. In one, the device had embolism, to the right pulmonary artery and was operated 24 hs afterwards without complications. Seven had residual shunts, two had subsequent surgery, two are being followed (one for mild and one for moderate residual shunt). In the other three cases we inserted a second device. We used a 12 mm device in two cases and a 17 mm device in the other. Two cases had total occlusion 24 hrs after and in one had mild residual shunt without clinical repercussion. There were no complications. All had electrocardiographic and clinical improvement, take no medication, and their cardiomegaly had decreased (Cardiac index pre 61 vs post 54%). In conclusion the insertion of a second device is safe and effective alternative for residual shunt after first Rashkind occluder.

[Observer variation in diagnostic procedures related to cardiothoracic surgery]. / Variabilidad de observador en procedimientos diagnósticos afines a la cirugía cardiotorácica.

The results reliability is a predominant condition in the validity of clinical research. The observer agreement determination is a useful procedure in the confirmation of the obtained results in clinical research. The present work is a presentation of the basis about observer agreement and a review of national publications in cardiology, pneumology and cardiothoracic surgery between january 1980 and july 1993, where we found just two publications with the application of observer agreement determination in echocardiography, electrocardiography, microscopy and hemodynamics. It was concluded that is necessary the increase in determination of observer agreement and inform this results in our publications, excluding the variability attributed to patients, diagnostics equipment or the circumstances.

[Insulin resistance: an etiological factor in essential arterial hypertension and coronary cardiopathy]. / Resistencia a la insulina: factor etiológico de la hipertensión arterial esencial y de la cardiopatía coronaria.

Insulin resistance has been implicated in the pathogenesis of essential hypertension. Studies from other countries discovered insulin resistance; in people with essential hypertension in was also associated with obesity, however, insulin resistance was found in lean people too. In obesity, insulin resistance occurs secondarily to many physiopathological states and circulating factors which adversely affects insulin action. The metabolic abnormality in this action was mainly found in relation to abdominal fat; in other cases, insulin resistance was found to be inherited. Hyperinsulinaemia can actually increase blood pressure and is associated with venous and arterial thrombosis and it also rises lipid levels. It is interesting too that insulin resistance and hyperinsulinaemia are associated with impaired fibrinolysis through high levels of fibrinogen and plasminogen activator inhibitor of endothelial type and in identifying individuals prone to myocardial infarction. Some antihypertensive drugs like beta-blockers, methyl-dopa and diuretics increase insulin resistance, while angiotensin converting enzyme-inhibitors have not shown any adverse metabolic affects. Alfa-1-blocker were beneficial and alfa-2-agonists were neutral, whereas calcium channel-antagonists are still in controversy. Treatment should be designed to improve the metabolic state; physical exercise, a diet rich in fruit, vegetable and rott vegetables, the reduction of abdominal fat and, finally, the use of antihypertensive drugs which decrease insulin resistance would be expected to reverse hyperinsulinaemia. Biguanides like metformin have also been found to reduce insulin resistance.