[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.

[Stent in protected and non-protected left main coronary artery: results and short-term follow-up]. / Stent en tronco coronario izquierdo protegido y no protegido: resultados y seguimiento a corto plazo.

UNLABELLED: We examined the immediate and short-term outcomes after stenting protected and unprotected left main coronary artery (LMCA) stenoses, in patients with normal ventricular function. Left main coronary artery disease is regarded as an absolute contraindication for coronary angioplasty, because it has been associated with high procedural morbidity and poor mid-term results. Between february 1995 and february 1999, 596 procedures were performed in 468 patients. Ten patients who had disease involving the left main coronary artery were included. They were not candidates for coronary surgery. The post-stent antithrombotic regimens were aspirin and ticlopidine. The procedural success rate was 100% without episodes of subacute thrombosis. Three to six months follow-up angiography was performed in all, restenosis occurred only in two patients, there were two repeat PTCA (20%) and there were no deaths. CONCLUSIONS: Stenting of unprotected and protected left main coronary artery stenoses may be a safe and effective alternative to surgery in carefully selected patients with normal left ventricular function. The results of our study suggests that when patients have prohibitive surgical risks, elective LMCA angioplasty and/or stenting maybe undertaken with a high procedural success rate as an effective alternative to CABG in carefully selected patients. Further studies in larger patient populations are needed to assess late outcome.

[Immediate results of coronary stent implants in octogenarian patients]. / Resultados inmediatos post implante de stents coronarios en pacientes octogenarios.

UNLABELLED: We review our experience and also evaluate the clinical and angiographic results of octagenarians patients subjected to percutaneous transluminal angioplasty and endovascular prosthesis (stents). In the period between february 1995 and august 1998, 532 procedures were performed in 400 patients, we describe a subgroup of 51 patients, who rejected surgical treatment or were considered non appropriate candidates for this therapeutic approach. Ages ranged 71 a 85 years mean (74.09 +/- 3.1). Sex: 37 male and 14 female, their clinical presentation was severe angina according to Canadian Society of Cardiology (CSC) in 64%. In 64% previous myocardial infarction and multivessel disease in 58.8%. The mean percentage of coronary obstruction was 90 +/- 9.2 and ejection fraction 51.6 +/- 8.8, the immediate angiographic success was 88.3% six patient (12%) died during 36 to 72 hours post-procedure from different causes. The follow-up period was 3 to 48 months, but had angiographic control just eighteen patients (35%). Eighteen cases were lost to follow-up for different reasons. Two patients died of non cardiac causes. CONCLUSIONS: Stent implantation has an angiographic and clinical success with low complications profile. It is a therapeutic option in the management of advanced coronary artery disease in this frail group.

[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.

[Electrocardiographic data suggesting anteroseptal myocardial infarction, in presence of infarction of the left ventricle]. / Datos electrocardiográficos sugestivos de infarto del miocardio anteroseptal, en presencia de infarto del ventrículo derecho.

We present a case of right ventricular myocardial infarction, secondary to postangioplasty occlusion of ventricular ramus of the right coronary artery, that developed electrocardiographic changes suggestive of septal myocardial infarction, this diagnosis was eliminated through angiographic study. We conclude that the carefully analysis of the electrocardiographic changes in ST segment in V1 to V4 can guide to the diagnosis of right ventricular myocardial infarction. For that reason we recommend the routinary register of the right electrocardiographic derivations as V3R and V4R, and left derivations V7 and V8, that is, the thoracic circle, in all patients with acute myocardial infarction regardless its location.

[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.

Correlation between dobutamine stress transesophageal echocardiography, thallium 201-dipyridamole scintigraphy and coronary angiography in the early detection of myocardial ischemia.

In order to establish the sensitivity and specificity of transesophageal stress echocardiography with dobutamine (TEE-dobutamine) in the early detection of myocardial ischemia we studied 30 consecutive patients from the Coronary Care Unit (CCU) of the Hospital de Cardiología, Centro Médico Nacional Siglo XXI. The results were correlated with thallium-201-dipyridamole scintigraphy (TDS), and coronary angiography. Two groups were formed: Group I-20 patients, 18 females/2 males, aged 37-73 years (mean 55 years) within the first week of myocardial infarction and/or unstable angina; Group II-10 patients, five males/five females, aged 35-65 years (mean 48 years) with atypical chest pain but with high suspicion of CHD. All group I patients, and none of group II, had significant stenoses on coronary angiography. Twenty patients had a positive TDS (18 patients from group I and two from group II). Twenty one patients had a positive test with TEE-dobutamine, 20 from group I and one from group II, which yields a sensitivity of 100%, a specificity of 90%, positive predictive value of 95% and negative predictive value of 100%.

[Elevation of total urinary catecholamines in patients with subarachnoid hemorrhage]. / Elevación de catecolaminas urinarias totales en pacientes con hemorragia subaracnoidea.

We designed a prospective study in order to evaluate total urinary catecholamines in patients with subarachnoid hemorrhage (SAH) and correlate them with some prognostic factors and its complications. We studied 24 patients: 19 were normotensive, five had had a previous arterial hypertension that persisted during the SAH, and five developed the hypertension during the SAH. The latter showed cardiac complications with a more severely affected Hunt and Hess scale and a higher level of excretion of urinary catecholamines than the normotensive patients (p < 0.003). The cases with previous arterial hypertension that persisted during the SAH had more complications than the normotensive patients but in a lesser degree compared to chose who developed the hypertension during the SAH.

[Percutaneous mitral commissurotomy with Inoue's technic and pregnancy. The initial experience in Mexico]. / Comisurotomía mitral percutánea con técnica de Inoue y embarazo. Experiencia inicial en México.

From March 1986 to January 1993, we performed percutaneous balloon mitral commissurotomy (PBMC) in ninety-one patients with rheumatic mitral stenosis, two of them during pregnancy. The gestational age at the time of valvotomy was thirty and twenty-seven weeks respectively. Balloon Inoue technique in both cases resulted in improvement in mitral valve area (0.8 vs 1.6 and 0.7 vs 1.9 cm2) and in mean mitral gradient (19 vs 4 and 12 vs 0 mm Hg) immediately after dilation, without residual atrial septal defect or mitral insufficiency. There were no complications. The estimated radiation exposure to the fetus was of 6.4 minutes of fluoroscopy and 6 seconds of angiography. To limit of X-ray irradiation, we used color Doppler echocardiography during dilatation in both cases. The subsequent course of gestation was uncomplicated and normal babies were delivered in both cases. Fetus protection against ionising radiation was assured by lead mantles. In the follow-up the mitral valve area was 1.7 and 2.1 cm2, 15 and 4 months later respectively. PBMC can be performed safely during pregnancy and is effective in increasing the valvular area and relieving symptoms. It offers an excellent alternative for the pregnant patients, with severe mitral stenosis. The risk to the fetus appears lower than previous reports of surgical commissurotomy performed during pregnancy.

[Balloon catheter valvuloplasty for calcified aortic stenosis in adults. Report of a case and review of the literature]. / Valvuloplastía con catéter de balón en la estenosis aórtica calcificada del adulto. Reporte de un caso y revisión de la literatura.

The first procedure of balloon valvuloplasty in adult calcific aortic stenosis was performed in Mexico on July 17 of 1987. It was a 69 year old female with calcific aortic stenosis and unstable, progressive angina pectoris. Cardiac catheterization showed trans-aortic gradient of 90 mmHg, minimal aortic regurgitation and ejection fraction of 85 percent. Aortic valvuloplasty was performed immediately after cardiac catheterization using the arterial retrograde way by means of a 15 mm. in diameter catheter initially and another of 18 mm. in diameter afterwards. At the end of procedure the gradient diminished to 56 mmHg and an slight increase of the aortic insufficiency was observed. The Doppler echocardiogram showed decreased severity of the stenosis. The patient was discharged asymptomatic and continued to do well for six months. She died suddenly after that period of time. A review of the literature is also presented.

Changes in cardiac repolarization and ventricular conduction in a case of acute hematomyelia. Report of a case.

A twenty year old man presented an acute hematomyelia at T2-T3 level and had electrocardiographic changes suggesting subendocardial and subepicardial ischemia; he also had precordial pain and elevation of the MB fraction of creatine phosphokinase. Neurons providing heart inervation are located at the T2-T3 spinal level. The electrocardiographic changes observed were considered neurogenic in origin and were transient. Although there are experimental reports showing electrocardiographic changes associated with compression of the upper part of thoracic spinal cord, this is the first report to our knowledge, in which an acute spinal injury is shown to be associated with neurogenic changes in ventricular repolarization simulating acute myocardial ischemia.