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Biomedical subjects

M Cárdenas

Publications and source records attributed to M Cárdenas.

At least 73 records · Page 4Linked to original sources

[Clinical development of the in-hospital phase of acute myocardial infarction in patients treated with intravenous streptokinase].

In order to determine the clinical in-hospital course of patients with acute myocardial infarction treated with intravenous Streptokinase (SK), 132 patients were studied divided as follows: Group I: 44 patients who arrived to the hospital within 6 hours from the onset of symptoms and received fibrinolytic therapy. Group II: 44 patients who arrived more than 6 hours delay and did not receive SK. Group III: 44 patients who arrived less than 6 hours delay but they did not receive SK. The overall hospital mortality was 2.2% in the SK recipients versus 4.4% in the group II (Odd ratio 0.95, p = NS) and 13.6% in group III (Odd ratio 0.79, p greater than 0.05). The incidence of hemorrhagic episodes was not increased in SK recipients. In-hospital period differences between groups were explained by protocol studies and postoperative complications in patients that needed further revascularization procedures.

Aged↗

[Silent myocardial ischemia in unstable angina and acute myocardial infarction. Prospective clinical study].

To establish the prevalence and characteristics of silent myocardial ischemia in patients with unstable angina and acute myocardial infarction and its possible correlation with coronary artery lesions; two groups patients were studied, fifteen with unstable angina and fifteen with acute myocardial infarction. In all patients a continuous 24 hours ECG recording was made with a solid state microprocessor for ST variation analysis, and all underwent coronary arteriography and ventriculography, the severity of coronary heart disease was determined by Gensini scoring system and the coronary angiography morphology was studied. In 86% patients with unstable angina ischemic ST changes were found, 90% of these episodes were silent. There were 66% of the patients with acute myocardial infarction and ST ischemic changes of these 75% were silent. There was no correlation with the ischemic myocardium score index, nor with the angiographic morphology or the heart rate. Therefore it can be said that myocardial ischemia is a result not only of anatomic factors but of many others such as vasoconstriction, endothelial, myocardial, systemic and hemorheological alterations.

Aged↗

[Predictive value of sudden death in repetitive ventricular extrasystole].

Prognostic significance of repetitive ventricular premature contractions (RVPC) were evaluated retrospectively in 452 patients studied with a 24 hours continuous electrocardiographic monitoring (Holter System). The patients were analysed in two groups: Group 1.- 199 patients; with primary heart disease: previous myocardial infarction (MI) in 114 patients, angina pectoris (AP) in 29 cases, congestive cardiomyopathy in 19 cases (COCM); hypertensive heart disease (AHCD) in 14 cases, Atherosclerotic heart disease (AEC) with conduction disturbance and without angina pectoris 23 cases. Group 2.- 253 patients without heart disease. Two different types of RVPCs were defined: Type A: as the occurrence of self-terminating two (coupled) or multifocal. RVACs Type B: Self limited ventricular tachycardias or "R on T phenomena". Forty patients of group 1 had RVPCs (23 type A and 17 type B) and 22% of them had sudden death (SD). Among 199 patients with structural heart disease, 74 had congestive heart failure (CHF) and 12 of these had RVPCs. 83% of patients with RVPCs died suddenly. No patients with CHF and without RVPCs had SD. In group 2 (without heart disease no patients died on the follow up, and 6% of them had RVPCs (68% type A and 32% type B). Coronary arteriographic and ventriculographic findings were reviewed in 92 patients with previous MI. In the patients followed 40 has RVPCs, and 9 of them had SD. Those 4 cases were cases of MI (25% of the patients with MI having RVPCs), 4 (25%) with COCM, and 1 (2.5%) with hypertensive cardiac disease. Thus, patients with MI or COCM had higher incidence of RVPCs, so they are at a high risk for sudden cardiac death.

Cardiac Complexes, Premature↗

[Predictive value of ventricular extrasystole in the exertion test and its relation to the magnitude of coronary damage].

The predictive value of ventricular arrhythmias, associated with treadmill exercise testing was evaluated in 115 patients undergoing coronary angiography and left ventriculography within three months of the exercise test. 39 patients with ventricular arrhythmias (at least one premature ventricular complex, paired complex or ventricular tachycardia) had a higher or multivessels disease than the patients without ventricular arrhythmias (P less than 0.05). This study demonstrated that ventricular arrhythmias detected at exercise testing are related to the extent of coronary artery disease, and the presence of the left ventricular disfunction.

Cardiac Complexes, Premature↗

[Asymptomatic myocardial ischemia].

The concept, physiopathology, epidemiology, diagnostic procedures, prognosis and treatment of asymptomatic myocardial ischemia are reviewed. Hypotheses given to explain the absence of pain in the presence of myocardial ischemia are analyzed; Cohn's classification of asymptomatic myocardial ischemia is described and complemented with other clinical entities of painless myocardial ischemia. Prevalence of asymptomatic myocardial ischemia in different groups of patients is also discussed as well as the most important characteristics of diagnostic procedures. Finally the prognosis of asymptomatic myocardial ischemia is analyzed and the present therapeutic possibilities are discussed.

Coronary Disease↗

[Value of the DI and AVL leads in the diagnosis of infarction of the right ventricle].

The present study attempts to analyze the sensitivity and specificity of the S-T segment depression in I and a VL leads in the diagnosis of postero-inferior myocardial infarction with right ventricular extension. Thirty four specimens from autopsies performed in the Instituto Nacional de Cardiología Ignacio Chávez with histopathological evidence of postero-inferior myocardial infarction, with an adequate clinical, enzymatic and electrocardiographic documentation were studied. In 23 the postero-inferior myocardial infarction had extended to the right ventricle (group I) and in ll only left ventricle was involved (group II). There were not significative differences in severity and extension of coronary obstructions between the two groups studied. Sensitivity of S-T segment depression in DI lead ad diagnosis of right ventricular extension had 82.6%, specificity 90.9%, positive predictive value 95%, negative predictive value 71.4% and diagnostic efficiency 85.2%. Sensitivity of S-T segment depression in a VL lead as diagnostic of right ventricular extension was 91.3%, specificity 81.8%, positive predictive value 91.3%, negative predictive value 81.8% and diagnostic efficiency 88.2%.

Electrocardiography↗

[Demonstration of the role of stimulation of purinergic receptors in the electrophysiologic effect of adenylic compounds in man].

In order to study the mechanism of action of AMP on the AV node conduction, 10 patients with re-entrant tachycardia including the AV node in the circuit (SVT) were studied. The mean age was 32.8 +/- 11.1. Tachycardia was induced by programmed atrial stimulation. Electrophysiological studies were made in all the cases. Intravenous injection of AMP suppressed SVT in all the patients in the first part of the study. The mean doses was 0.095 +/- 0.037 mg/Kg., and the mean time was 15.2 +/- 2.6 sec. In the second part (after 0.04 mg/Kg. IV atropine) the induced SVT was suppressed with a mean doses of 0.122 +/- 0.45 mg/Kg of AMP (P = NSD) in a mean time of 16.2 +/- 2.2 sec. (p = NSD). In the last part of this study the intravenous injection of aminophylline (4 mg/Kg) avoided the suppression of induced SV T in 8/10 patients. In to patients the AMP doses was 0.250 mg/Kg., and in the other 0.075 mg/Kg. Our studies demonstrated that the mechanism of action of AMP is by means of agonistic stimulation of purinergic receptors in the AV node.

Adenosine Monophosphate↗

[Metabolic disorders in survivors of myocardial infarct].

Several lines of evidence have clearly established the role of lipoproteins as risk factors for the development of atherosclerosis. Epidemiologic studies from different countries have found that about one third of myocardial infarction survivors under 60 years of age are hyperlipidemic. The acute stress reaction occurring in the first hours following an acute myocardial infarction causes distinct changes in the patient's metabolic profile, these changes include a significant reduction of total cholesterol and cholesterol associated with low density lipoproteins and a usually mild elevation of blood glucose. With the purpose of establishing the prevalence and severity of lipoprotein disorders found in myocardial infarction survivors living in Mexico city we conducted a prospective study of 106 consecutive admissions to the coronary care unit at the National Institute of Cardiology with the fully proven diagnosis of acute myocardial infarction, we included only patients younger than 60 years of age that could be sampled within the first 72 hours of the appearance of typical symptoms, at this time the coronary risk factor profile was assessed and blood samples were drawn (acute sample). After three months of the diagnosis we sampled 81 of the original 106 patients (chronic sample). The comparison of these 81 patients showed remarkable differences in the lipid values obtained on each sample. The mean value for total cholesterol in the acute sample was 225 mg/dl whereas the corresponding value for the chronic sample was 240.5 mg/dl (p less than 0.005). This difference was also highly significant for the low density fraction. On the basis of the chronic sample analysis we estimated a prevalence of hyperlipoproteinemia of 35.8%. (II: 18.5%, III: 2.5%, IV: 14.8%), an additional subgroup of 10 patients (12.3%) had the hypo-HDL phenotype raising the number of subjects at risk for atherosclerosis to as high as 48.1% considering only the lipoproteins. The prevalence figures for the rest of the risk factors were as follows: 70.3% for tobacco smoking, 35.8% for Systemic Arterial Hypertension, 33.4% for Obesity and 30.8% for Diabetes Mellitus. Among the group of 81 patients, 17 were known diabetics, eight additional cases of Diabetes Mellitus were diagnosed at the chronic phase (two with fasting hyperglycemia and six with diagnostic oral glucose tolerance tests). The "acute plase" glycemia for these eight subjects was significantly higher (mean: 98.4 mg/dl) than the corresponding value for the non diabetic patients (mean: 83.4 mg/dl p less than 0.002), the seventeen known diabetics had a mean glycemia of 150.6 mg/dl in the acute sample.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗

[Digital radiocardioangiography as an auxiliary method for the precise localization of zones of myocardial concentration of 99mTc-Sn(II)-pyrophosphate. Preliminary report].

A new method is introduced for the superposition of 99mTc-pyrophosphate (PiF) myocardial images on the isolated images of the radioangiocardiographic dextrophase and levophase, in order to include cardiac anatomical references for the accurate topographic localization of the PiF concentration areas. Results in two different patients are presented. In one of them, the PiF concentration was evident at the inferoseptal, inferoapical and posterolateral regions of the left ventricle. In the other, the PiF concentration was evident at the same areas than in the former plus the inferoanterior region of the right ventricle. Our project is to validate this procedure by correlating its results with those obtained through other clinical methods that detect right ventricular infarction.

Angiocardiography↗

[Importance of the early intravenous administration of streptokinase in acute myocardial infarct].

To evaluate the importance of early initiation of fibrinolytic therapy with intravenous streptokinase (IVSK), we studied 34 consecutive patients, within less than six hours of the onset of acute myocardial infarction, who were treated with 1.5 million units of intravenous streptokinase. All the patients had coronary angiograms in the first seventy two hours. We correlated the angiograms with the time of onset of the IVSK. The patients were divided into 3 groups: Group num. 1: From zero to two hours (twelve patients); Group num. 2: From two to four hours (13 patients); and Group num. 3: From four to six hours (nine patients). We had angiographic reperfusion in twenty-four patients (70.2%) P less than 0.05. We observed reopening in the patients of group num. 1 (83.3%); in group 2, nine patients (69%) and in group num. 3, five patients, (55.5%), with statistical significance only in group num. 1 (p less than 0.05). We also demonstrated the utility of the electrocardiographic and enzymatic criteria to predict reperfusion. No mortality was related to the procedure. We concluded that a higher percentage of reperfusion is obtained the sooner intravenous streptokinase therapy is initiated.

Coronary Circulation↗

[The Wenckebach phenomenon in patients with acute myocardial infarction].

To show the incidence of second degree Auriculoventricular block (AVB) with Wenckebach phenomenon (WF) 1336 patients with acute myocardial Infarction (AMI) were studied. We found 67 cases with WF 5.0% from the total group of AMI and the 33.83% form the group with any type of AVB. Fifty three were male and 14 female (4:1). 77.5% arrived to ICU for their first AMI and 22.38% for their second AMI. 43.26% were posteroinferior with extension to right ventricule; 36.0% pare posteroinferior, 10.4% anterolateral; 9.0% posterolaterals and 1.4% lateral. The onset time of WF in relation to the AMI set was 64.2% in the first 24 hours; and 17.9% for the 24-48 hour group as well as for those over 48 hours. The duration of the WF in 43.3% was lees than 24 hours 19.4%; between 24-48 hours; 25.4% more than 48 hours and 11.9% was transient. The WF was always present with heart rate under 110x'. In 9 patients it occurred with sinus bradycardia with a 48 to 40x' heart rate. The QRS duration was from 80 to 90 msec in 91.0% and from 100 to 120 msec in 9.0%; 4.47% of them had right bundle branch block previous to WF. 10.4% had progression to Mobitz II and 11.9% lead to complete AVB. Mortality was the 2.98% in the group their first AMI; and 4.47% in the group with their second AMI.

Adult↗

[Diagnosis of ischemic heart disease by infusion of isopropylarterenol: comparison with ergometry and validation by coronary arteriography].

In order to evaluate isopropylarterenol infusion (ISO) as a diagnostic procedure in ischemic heart disease, we performed a clinical study in 54 patients controlled with exercise stress test (ERGO) and validated by coronary arteriography. Eighteen patients had normal coronary arteriographic findings and 36 had coronary artery disease. In both groups the hemodynamic response was similar in either test used (ERGO or ISO), when similar heart rates were reached. The sensitivity of ERGO was 80.55% and 86.11% for ISO and specificity of 77.72% and 72.26% respectively in the diagnosis of coronary artery disease. When both tests are associated their sensitivity is 83.30% and their specificity is 75.0% (Table V). The ISO test was not accompanied with adverse effects and could be considered as a useful method in the diagnosis of coronary heart disease, similar to ERGO. Additionally ISO could be applied to understand some physiopathological mechanisms of ischemic heart disease.

Adult↗