[The use of beta-blockers in pregnancy].
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Adrenergic beta-Antagonists↗
Biomedical subjects
L Colín Lizalde
Publications and source records attributed to L Colín Lizalde.
[Transtelephonic electrocardiography in Mexico. A report of the first 3434 cases].
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.
Adult↗
[Auricular flutter associated with an interatrial septal aneurysm submitted to radiofrequency ablation].
We present the case of a young man who began with type I atrial flutter, he had no response to antiarrhythmic drugs. The echocardiogram showed an atrial septal aneurysm in the region of the fossa ovalis. We performed an electrophysiologic study which showed an atrial flutter with atrial rate of 257 bpm, and 2:1/3:1 AV conduction. The flutter waves were negatives in leads II, III and a VF (type I atrial flutter). An endocardial mapping was obtained in order to localize the area of slow conduction. It was located in the isthmus of atrial tissue bounded by the inferior vena cava and the tricuspid valve annulus in the low posterior septal right atrium. In this area we applied radiofrequency energy in 10 occasions but the arrhythmia was not suppressed. With atrial pacing we achieve a concealed entrainment and then resumption of atrial flutter after cessation of pacing. After another 6 applications of radiofrequency in this same area in sinus rhythm, we paced the atrium without inducing any form of arrhythmia. He was asymptomatic 15 days later, but one month after the ablation, the flutter reappeared, we performed a second successful radiofrequency ablation. In this time he was asymptomatic.
Adult↗
[A new electrocardiographic algorithm for localizing accessory pathways using only the polarity of the QRS complex].
From 250 consecutive patients who underwent radiofrequency ablation of accessory pathways, we studied 102 patients with successful ablation of a single overt accessory pathway. All patients had manifested preexcitation on a baseline 12 lead electrocardiogram. None of this patients had additional congenital or acquired cardiac abnormalities which could have affected the QRS morphology. A new algorithm for localizing the AP site was developed, based only on the polarity of the QRS complexes in DIII, V1 and V2, without analysis of the delta wave. We could localize the accessory pathway in five sites with 88% of probability of success. This simplify the electrocardiographic analysis of Wolff Parkinson White and improvement the results of radiofrequency ablation.
Adolescent↗
[The DDD pacemaker implanted intravenously].
Retrospectively, we studied 66 consecutive patients in whom we implanted an intravenous DDD pacemaker. The indications were: AV block in 52 patients (79%), sick sinus syndrome in 5 patients (7.5%), both AV block and sick sinus syndrome in 4 patients (6%), and other causes in 5 (7.5%). The venous access route was by subclavian punction in 38 cases (57.5%) and by cephalic vein dissection in 28 (42.5%). With a mean follow-up of 16 months, there were complications in 11 patients (17%), in 9 of them, it was necessary a change in pacing mode different to DDD, and was possible to maintain a DDD pacing mode in 2 patients with a minimal reprogramming. The complications were: A) lost of sense and/or atrial capture in 10 patients (3 of them, had also loss of ventricular capture, one had pacemaker-mediated tachycardia, other had diaphragmatic stimulation and other had a severe infection of the pocket), B) atrial fibrillation appeared in another patient. At the implantation time there were significant differences between patients with and without complications on follow-up, the P wave amplitude was 1.86 +/- 0.75 mV in the first group vs. 3.06 +/- 1.52 mV in the latter group, p < 0.005, and the atrial pacing threshold was 1.10 +/- 1.17 microJ in the first group vs. 0.65 +/- 0.66 microJ in the latter group, p < 0.005. We consider that dual chamber stimulation is a well established form of therapy, although, it requires a more laborious implantation and specialized personal for its follow-up.(ABSTRACT TRUNCATED AT 250 WORDS)
Adolescent↗
[The response of ventricular tachycardia to adenosine administration].
Ten patients with ventricular tachycardia were studied. Two groups were formed. Group A included 5 patients with idiopathic ventricular tachycardia and group B included 5 patients with coronary heart disease. In all patients an electrophysiologic study was performed and monomorphic sustained ventricular tachycardia was induced through programmed stimulation. All patients received 12 mg of intravenous adenosine. The response was satisfactory in 3 of 5 patients in group A, with the presence of sinus rhythm. No response was seen in the other 2 patients. None of the patients in group B responded to the administration of intravenous adenosine. We concluded that adenosine may be useful in patients with cyclic AMP-mediated triggered activity ventricular tachycardia, in contrast to the coronary heart disease patients in which the mechanism is reentry. This interpretation is supported by results obtained in 15 experiments in canine heart.
Adenosine↗