[Radiofrequency ablation of permanent supraventricular tachycardia through an accessory pathway with slow retrograde conduction]. / Ablación con radiofrecuencia de taquicardia supraventricular incesante por una vía accesoria con conducción retrógrada lenta.

We present the case of a 6 year old boy with permanent junctional reciprocating tachycardia. The tachycardia had been present since 3 years before ablation and was treated with two drugs without good control. He began to complain of palpitations and shortness of breath on exertion and the left ventricle ejection fraction was 55% by echocardiography. We performed an electrophysiologic study which showed the most early atrial activation at the coronary sinus with a long V-A interval. Orthodromic AV reciprocating tachycardia was confirmed as the mechanism of tachycardia by demonstrating atrial pre-excitation when a premature ventricular stimulus was delivered at the time the His bundle was refractory. With the ablation catheter, the accessory pathway potential was recorded at the coronary sinus near the os. Radiofrequency current was applied with temperature control at 60 degrees C for one minute at this site with success. While on sinus rythm we performed programmed atrial and ventricular stimulation with isoproterenol infusion and there was no evidence of accessory pathway function. This patient is asymptomatic and on sinus rythm 6 months later.

[Transtelephonic electrocardiography in Mexico. A report of the first 3434 cases]. / La electrocardiografía transtelefónica en México. Reporte de los primeros 3434 casos.

The transtelephonic electrocardiographic system started in the 70's and it was used mainly in the study of heart disease, cardiac arrhythmias, syncope and sudden death. This report, include 3434 electrocardiogram (ECG) of patients whom visit the emergency room at the General Hospital and private clinic, using three different forms of transtelephonic monitors. The total population were 1715 males and 1719 females with average age of 52.2 +/- 28.8 years. 26.9% had was present in history of systemic hypertension, non-insulin dependent diabetes 12.3% and myocardial ischemic disease in 5.3%. The main ECG indications were chest pain 38.7%, most of them atypical angina, palpitations in 6.9% and dyspnea in 6.5%. 50.1% of the ECG were abnormal. The most important diagnosis were: tachyarrhythmias (25.2%), intraventricular conduction abnormalities (17.7%), myocardial ischemic disease (16%), and premature ventricular and supraventricular beats (11.6%). We concluded that the transtelephonic electrocardiographic system is a very useful method, and available now in Mexico. We detected a high percentage of electrocardiographic abnormalities, it was possible to give the right diagnosis of arrhythmias, acute myocardial infarction, old infarction, and to evaluate the pacemaker functionality. Finally, it helped to get in brief time the diagnosis and treatment in cases of acute myocardial infarction or severe arrhythmias.

[The surgical treatment of cardiac myxomas: 10 years of experience]. / Tratamiento quirúrgico de mixomas cardíacos: experiencia de 10 años.

Over a ten-year period (September 1980-July 1990) 3172 patients underwent open heart surgery in our hospital. Twenty five patients (0.78%) had a cardiac myxoma. There were 18 female and 7 male patients, mean age of 32.3 +/- 21 years (4-61). Left atrial myxomas were diagnosed in 18 patients, left ventricular myxoma in three, right atrial myxoma in two, and one in right ventricle; there was a biatrial myxoma in one case, another had biatrial and left ventricular myxoma. The clinical manifestations of right sided myxomas was congestive heart failure. Patients with left myxoma frequently presented embolic episodes. Myxoma diagnosis was made by means of chest films, EKG and two-dimensional echocardiography which proved effective in twenty four of our patients; cardiac catheterization was performed in ten of them. Symptoms before diagnosis lasted an average of 16.3 months and mean time from diagnosis to operation was 6.6 days. Different surgical approaches are analyzed and discussed. Concomitant surgical procedures were performed in five patients: mitral annuloplasty in one, mitral valve replacement in four (two biological and two mechanical prosthesis). In eight patients the resulting septal defect due to resection of pedicle was closed with pericardial or dacron patches. There were two operative deaths due to pulmonary emboli in one and multiple organ failure in other. Cardiac myxoma is the more frequent primary neoplasm of the heart; its "benign" nature is doubtful; cure by surgical excision can be considered in vast majority of patients and its morbidity is reasonably low.

[Coronary angioplasty as the treatment in different myocardial ischemic syndromes: a report of 121 consecutive cases]. / Angioplastía coronaria como tratamiento de diversos síndromes de isquemia miocárdica: informe de 121 casos consecutivos.

In 121 patients (93 males, mean age 53.9 years), percutaneous transluminal coronary angioplasty (PTCA) of 140 lesions was performed as treatment of symptomatic, single or multiple vessel disease, with the following clinical syndromes: stable angina pectoris (Group I) in 59 cases (48.8%), unstable angina (Group II) in 40 (33%), and angina or residual ischemia after thrombolysis for myocardial infarction (MI) (Group III) in 22 patients (18.2%). PTCA was successfully accomplished in 123 of 140 segments (87.8%), with a reduction in mean luminal stenosis from 87.3 +/- 13% (range 70-100) to 15 +/- 10% (range 0-30, p less than 0.00001). Successful results were obtained in 85.9% of patients (104/121) and they were 84.7%, 82.5% and 95.5% in Groups I, II and III, respectively. The procedure failed in 17 cases (14.0%), and within this group, 14 complications occurred (11.6%): 2 deaths (1.6%), 3 cases of MI, acute closure in 4, and emergency coronary bypass surgery in 5 patients. Late evaluation (6-8 months) revealed clinical and functional improvement in 71/98 patients (72.4%), and recurrent ischemic symptoms (no improvement) in 27 cases. Coronary angiography performed in 20, showed restenosis in 10, and progressive disease in 7 patients. In conclusion, PTCA is an effective therapeutic option in selected cases of symptomatic ischemic heart disease with suboptimal results to medical management alone.

The role of luminal pH in production of gastrin cell hyperplasia in the rat.

Truncal vagotomy is associated with diminished gastric acid production, gastrin cell hyperplasia, and elevated serum gastrin levels. To study the role of reduced antral luminal acidity in the production of gastrin cell proliferation, gastrin cell densities were quantitated in preparations involving exposure of the antral mucosa to a non-acid lumen at different levels of the gastrointestinal tract. Female Sprague-Dawley rats were divided into the following experimental groups: intact controls, shams, antral diverticulum on the jejunum, antral diverticulum on the ileum, and antral diverticulum on the colon. At death, 2 weeks, 2 months, and 6 months after operation, luminal pH was at least 5.8 for each group of rats with antral diverticula. No significant changes in gastrin cell numbers were observed in rats with jejunal or ileal diverticula. For those animals with colonic diverticula, gastrin cell counts were increased 55% at 2 weeks (503 +/- 23 cells per cm versus 320 +/- 13 cells per cm for shams). At 2 months gastrin cell numbers had increased further (639 +/- 54 cells per cm) in rats with antral diverticula on the colon. Gastrin cell proliferation was sustained at 6 months in this group. A factor other than reduced luminal acidity induces gastrin cell proliferation in antral mucosa exposed to colonic content. The responsible agent is not present in the small-bowel lumen. A non-acid luminal environment is not, by itself, a sufficient stimulus for gastrin cell hyperplasia.

The results of aggressive regional operation in the treatment of cancer of the floor of the mouth.

We reviewed the records of 94 patients with cancer of the floor of the mouth who were treated during a 15-year period to assess the results of an aggressive regional surgical approach. The primary tumor was excised with a 2 cm margin of normal tissue. A marginal or segmental mandibulectomy was performed in 84 of 94 patients. An ipsilateral radical neck dissection was performed in 86 of 94 patients. Contralateral suprahyoid dissection was combined with ipsilateral radical neck dissection in 52 patients. Bilateral radical neck dissection was performed in 10 patients. In the 1 to 16-year follow-up period, local/regional control was achieved in 91% of stage I patients, 83% of stage II patients, 68% of stage III patients, and 48% of stage IV patients. Determinant 5-year survival rates were T1--72%, T2--47%, T3--25%, and T4--28%.

In-continuity gastrointestinal stapling.

Several surgical procedures have been proposed to interrupt continuity of the gut, without transection, by means of a row of staples. Using the dog, we investigated the functional and histologic results of incontinuity stapling of the gastric antrum, the small intestine, and the colon. After creation of an end antrostomy, ileostomy, or colostomy, a staple line was placed proximal to the stoma (TA 55-4.8 mm staples). Decompression of the bowel proximal to the staple line was accomplished by an enteric anastomosis. Separation of the staple closure was detected by intestinal contents exiting from the stoma. Animals were sacrificed at the time of disruption, and specimens were obtained for histologic examination. Three of five antral closures broke down at a mean of 19.6 days after operation. All five small-bowel staple lines opened at a mean of 12.4 days. Five of five colonic staple lines disrupted 13.0 days postoperatively. The staples pulled through the bowel wall without losing their "B" shaped configuration. Microscopic examination showed intact mucosa across the staple line, with no submucosa to submucosa healing. Staple lines in the undivided small bowel or colon disrupt after approximately two weeks, due to lack of fibrotic healing. Staple interruptions of the gastric antrum also disrupt, but with less regularity.