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Biomedical subjects

F Torres

Publications and source records attributed to F Torres.

At least 55 records · Page 3Linked to original sources
PubMed1995

Short-term reproducibility of time domain, spectral temporal mapping, and spectral turbulence analysis of the signal-averaged electrocardiogram in normal subjects and patients with acute myocardial infarction.

The aim of this prospective study was to compare the short-term reproducibility of the signal-averaged ECG (SAECG) with three analysis techniques, conventional time-domain analysis, spectral-temporal mapping (STM), and spectral-turbulence analysis (STA), in a large series of normal subjects and patients with acute myocardial infarction (AMI). Two consecutive SAECGs were recorded in 225 consecutive patients 10.2 +/- 2.7 days after AMI and in 85 healthy volunteers. The visual, diagnostic, and quantitative reproducibility of the three techniques was compared. Time-domain analysis was the most reproducible method, having high R2 correlations, statistically fewer inconsistent diagnostic recordings, and statistically smaller differences compared with other techniques. STM was the least reproducible, justifying caution in its current form. Although STA was significantly less reproducible than time-domain analysis, it was also significantly better than STM. Two STA parameters, spectral entropy and interslice correlation mean, showed good reproducibility, suggesting that modification of this analysis technique could be useful in risk stratification.

Aged↗
PubMed1995

Follow-up patency of side branches covered by intracoronary Palmaz-Schatz stent.

To assess the risk of late side branch occlusion after Palmaz-Schatz stent deployment, we analyzed the angiographic evolution of 62 patients treated by successful stent implantation who had a total of 85 side branches starting from the stented segment. Side branches were considered minor (n = 39) when the diameter was < 1 mm and intermediate (n = 46) when the vessel had > or = 1 mm diameter. One angiographic follow-up study was available in all patients at 8 +/- 5 months. Eight minor branches presented some degree of stenosis at origin before stent deployment (4 totally occluded). After stent deployment, 32 (82%) of 39 remained unchanged and 3 became occluded. Late progression at origin occurred in 4 of 34 (3 occluded). Before stent deployment, 48% of the intermediate branches had some compromise degree at their starting point (1 totally occluded). Eight of 45 intermediate branches became occluded after stent implantation. Late progression at origin happened in 5 of 32 branches (2 occluded). Some degree of follow-up stenosis regression at the origin was observed in 22 (26%) of 85 arteries. Neither clinical nor angiographic factors could be identified as predictors of late side branch occlusion or stenosis progression at its origin. Later occlusion or progression at origin of a side branch covered by a Palmaz-Schatz stent seems to be an uncommon occurrence (7% and 12% respectively) that cannot be predicted by angiographic or clinical factors. On the contrary, regression at follow-up of a side branch-origin stenosis can also come about.

Adult↗
PubMed1995

[Acute myocarditis with severe cardiac dysfunction in the pediatric population. The evolution and differential characteristics with respect to adult myocarditis].

AIMS: The aim of our study was to assess the spontaneous outcome of acute myocarditis associated with severe cardiac dysfunction in children, as well as to compare these features with those occurring in adult patients. METHODS: Fifty patients consecutively diagnosed of acute myocarditis during the last 7 years in our hospital were studied; 15 patients were children younger than 14 years, and 35 were adults. Immunosuppressive therapy was not used in any patient. RESULTS: Mean age was 2 +/- 3 years in children, ranging from 2 months to 12 years. One patient required temporary pacing for a third-degree atrioventricular block, while the remaining 14 children had severe congestive heart failure, with a left ventricular ejection fraction of 30 +/- 12% (16 to 44%). After a mean follow-up of 21 +/- 26 months, only 3 children died, at 1, 4 and 10 months after the initial diagnosis. Death was sudden in all 3 patients. Left ventricular ejection fraction rose to 45 +/- 14% at 1 month after diagnosis, and to 58 +/- 15% at the end of follow-up. Unfavorable evolution (death or evolution to chronic dilated cardiomyopathy, with a left ventricular ejection fraction < 45%) occurred in 6 children (40%) at 1 month after diagnosis and in only 4 (25%) at the end of follow-up. The 9 children with 1-month favorable outcome were alive and had an ejection fraction > 45% at long-term, while only 2 of the 6 children with 1-month unfavorable outcome were alive and had an ejection fraction > 45% at long-term. Only the 3 children who died had an ejection fraction < 30% at 1-month. Favorable outcome was more frequent in children that in adult patients with acute myocarditis (75% versus 46%). CONCLUSIONS: The outcome of acute myocarditis with severe cardiac dysfunction was favorable in a majority of pediatric patients; this favorable evolution was less frequent in adults. Patients in whom left ventricular ejection fraction did not increase at short-term had a higher risk of death, and they should probably be considered for heart transplantation.

Acute Disease↗
PubMed1995

General anesthetic effects on compound muscle action potentials elicited by single or dual spinal cord stimulation.

The aim of this study was to determine the optimal conditions, during general anesthesia, to obtain reproducible monitoring of compound muscle action potentials (CMAPs) as a means to evaluate motor tract integrity. The CMAPs were recorded in the soleus muscle of cats and were elicited by either single or double pulse stimulations (with various amplitudes and interpulse durations) of the spinal cord via an epidural electrode. The effects of various depths of general anesthesia with halothane, enflurane, isoflurane, or propofol on such recordings were also determined. For each agent, the CMAP amplitudes were significantly greater following double pulse stimulations (2-ms optimal interpulse duration) relative to single pulses. The CMAP amplitudes elicited by double pulse stimulations were the same at propofol concentrations of 50, 100, 150, and 200 micrograms/kg/min, whereas those for each volatile anesthetic, at all concentrations studied (0.5%, 1.0%, 1.5%, or 2.0%), were significantly lower. It was concluded that to obtain reliable CMAP amplitudes, general anesthesia with propofol should be employed and the potentials should be evoked by double pulse stimulations.

Action Potentials↗
PubMed1995

[For whom and when is a heart transplant indicated].

Selection of receptor has a great importance in the field of heart transplantation, due to its influence on short and long-term results after transplantation and to a better profit of available donors and resources. Although several parameters of prognostic value in patients with severe heart failure have been suggested, the indication and timing of heart transplantation are still based on a accurate assessment of contraindications or risk factors in the receptors, as well as on the clinical and functional condition of patients while receiving an adequate medical therapy.

Adult↗
PubMed1994

The effects of volatile anesthetics on the relative amplitudes and latencies of spinal and muscle potentials evoked by transcranial magnetic stimulation.

STUDY DESIGN: The effects of halothane, enflurane, or isoflurane on motor-evoked potentials via transcranial magnetic stimulation were investigated in cats. Time and dose effects on muscle potentials and spinal potentials were determined by measuring relative changes in amplitudes and latencies. METHODS: In 16 cats, muscle potentials and spinal potentials were evoked transcranially using magnetic stimulation. Potentials were recorded every 2 minutes for 10 minutes at end-tidal anesthetic concentrations of 0.25%, 0.5%, 0.75%, or 1.0%, and for 10 minutes after agents were removed. RESULTS: These anesthetics significantly attenuated the amplitude, but not the latency of muscle potentials. Effects were reversible and time and dose dependent. In contrast, these agents had little or no effect on amplitudes or latencies of spinal potentials. CONCLUSIONS: Monitoring intraoperative changes in spinal potentials may provide useful information regarding motor pathway assessment, because anesthetics have minimal effects on spinal potentials, whereas this is not so for muscle potentials.

Anesthetics, Inhalation↗
PubMed1994

Multicentre hospital drug utilization study on the prophylaxis of venous thromboembolism. The Venous Thromboembolism Study Group of the Spanish Society of Clinical Pharmacology.

1. Thromboembolic disease (TED) is an important cause of in-hospital morbidity and mortality. Although different prophylactic approaches have been shown to be effective and cost-effective, surveys have suggested that they are underused. The aim of this study was to estimate the prevalence of use of TED prophylaxis in our hospitals. 2. All patients admitted on a specified day to the Internal Medicine and General Surgery wards of seven Spanish university hospitals were included in the study. They were identified cross-sectionally and followed up until discharge or for 15 days. Information about the following variables was collected: risk factors for venous thromboembolism, prophylactic measures used (if any), contraindications to the use of each specific drug or other prophylactic measure, and dosage schedule of the drug used, if any. 3. Nine hundred and thirty-nine patients (53% men) were studied. The most common risk factors for venous thromboembolism were: age > or = 40 years (802; 85%), major surgery (298; 32%), immobilization > or = 6 days (285; 30%), obesity (241; 26%), and cancer (202; 22%). 4. Prophylactic measures were used in 320 patients (34%). Of these, 297 (93%) received heparin, mainly as low molecular weight heparins (248, 78%); physical measures were rarely used. 5. Five hundred and eighty-three patients (62%) fulfilled criteria for moderate or high risk of venous thromboembolism; only 275 (47%) of them received any form of prophylaxis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

[Infectious endocarditis in non-addict patients without predisposing heart disease. Differential features].

INTRODUCTION AND AIMS: Although uncommonly, infective endocarditis in non-addict patients may involve people without predisponente heart disease. The aim of our study was to assess the clinical and prognostic features of this type of endocarditis and to compare them with those of the more common type of endocarditis with underlying lesion. METHODS: With this aim, we have reviewed 71 consecutive cases of non-addict infective endocarditis diagnosed in our hospital in the last 7 years; there was no preexisting cardiac lesion in 9 patients (13% of all endocarditis and 21% of native valve endocarditis), while underlying heart disease, including mitral valve prolapse, was present in the remaining 62 patients. RESULTS: Mean age was significantly lower in 9 patients without preexistent lesion (28 +/- 18 versus 46 +/- 17 years, p < 0.01), while there was no differences for gender. Infection involved the aortic valve in 56%, the tricuspid or pulmonary valve in 33% and the mitral valve in only 11% of the patients without underlying cardiopathy (for 44%, 4% and 49%, respectively, in patients with cardiopathy). Staphylococcus aureus caused 67% of cases in patients without cardiopathy and only 9% in those with cardiopathy. Surgery was required in a similar proportion by both groups of patients (55% and 56%), although mortality was more than twice higher in patients with prior cardiac lesions (25% versus 11%). CONCLUSIONS: A significant proportion of non-addict infective endocarditis involves patients without predisponente heart disease. These cases have some differential features (younger age, aortic and right heart valves involvement, S. aureus as the main causative agent and lower mortality) in comparison to those of endocarditis in patients with underlying cardiopathy.

Adolescent↗
PubMed1994

[The echocardiographic findings in patients with brain death. The implications for their selection as heart transplant donors].

INTRODUCTION AND AIMS: Brain death causes myocardial impairment by some mechanisms not yet well understood. The aim of this work was to assess the echocardiographic features found in these patients and their implication in donor selection for heart transplantation. METHODS: With this aim, we have studied 38 consecutive patients with brain death assessed as possible donors for heart transplant in our hospital in the last 3 years. Age was 23 +/- 13 years; 77% were male. No history of cardiac disease was present in any patient. An adequate transthoracic echocardiogram was obtained in 74% of patients; transesophageal view was used in the remaining 26%. RESULTS: Echocardiogram was strictly normal in only 14 patients (37%). Mild valvular alterations were found in 5 patients (13%); a dilated aortic root in 1 (3%); moderate concentric left ventricular hypertrophy in 5 (14%); mild pericardial effusion in 1 (3%); mild septal hypokinesia with normal left ventricular ejection fraction in 4 (10%); abnormal left ventricular diastolic function in 7 (18%); and diffuse hypokinesia with ejection fraction less than 60% in 14 (37%). In 7 patients (18%) ejection fraction was lower than 40% (one of them was cocaine-addict). Mean ejection fraction was 59 +/- 15% (23 to 83%). Only 2 of the 19 (10%) donor hearts implanted in our hospital showed early dysfunction after transplant, but no relation to pretransplant ejection fraction was found. Ejection fraction increased from 62% pretransplant to 73% at one week after transplant in the other 17 cases. CONCLUSIONS: Brain death commonly causes alterations of left ventricular function, and this impairment is severe in almost 20% of cases. These echocardiographic features must be known when selection of donors for heart transplantation is concerned.

Adolescent↗
PubMed1994

[The incidence, mechanisms and clinical factors predictive of sudden death in patients with severe heart failure evaluated in anticipation of heart transplantation].

INTRODUCTION AND OBJECTIVES: Sudden death is not uncommon in patients with severe congestive heart failure. The aim of our study was to assess the incidence, mechanisms and clinical predictors of sudden death in a large series of patients with severe congestive heart failure evaluated for heart transplantation. METHODS: With this aim we have reviewed our experience on 240 consecutive patients with severe heart failure studied in our hospital from May 1986 to June 1992. Heart failure was due to ischemic heart disease in 35% of patients and idiopathic dilated cardiomyopathy in 65%. Age was 47 +/- 12 years, left ventricular ejection fraction was 20 +/- 6%, and symptom class was IV in 88% of patients and III in 12%. RESULTS: Sixty-eight of the 240 patients (28%) died without transplantation. Death was sudden in 21 patients (31% of deaths, and 9% of all patients), due to heart failure in 41 (68%), and due to malignancy (ampuloma) in 1 (1%). Mechanism of sudden death could be identified in 12 cases: ventricular tachycardia/fibrillation in 8 and bradycardia/electromechanical dissociation in 4. On multivariate analysis (stepwise logistic regression), a lower tolerated captopril dosage (p = 0.004), a lower systolic blood pressure (p = 0.079) and a history of a ventricular tachycardia/fibrillation (p = 0.073) were independent predictors of sudden death. CONCLUSIONS: It seems possible to identify, between patients with severe heart failure, a subgroup of patients at higher risk for sudden death by means of such simple clinical parameters.

Acute Disease↗
PubMed1994

[Short- and long-term course of heart transplantation recipients with severe dysfunction of the graft associated with acute rejection].

INTRODUCTION AND OBJECTIVES: Acute rejection is still a common cause of death after heart transplantation, in spite of cyclosporine. The aim of our study was to assess the incidence of severe graft dysfunction associated with acute rejection and the short and long-term outcome of these patients. METHODS: Ten of our 100 first heart transplant patients have developed rejection-induced severe cardiac dysfunction (left ventricular ejection fraction determined by echocardiography < 35% associated with 3A, 3B or 4 acute rejection). Clinical outcome, complications and evolution of left ventricular function were studied. RESULTS: Five patients were given intravenous methylprednisolone 500 to 1000 mg/day for 3 days. The other 5 patients had severe heart failure and received antilymphocyte antibodies. Three patients treated with methylprednisolone alone and one patient treated with antilymphocyte antibodies died within the first week after therapy. Left ventricular ejection fraction increased from 26 +/- 4% to 51 +/- 6% at 1 month after therapy in the 6 survivor patients. Four of the 6 survivor patients also died before 1 year after rejection (3 due to infection). Thus, long-term, overall mortality was 80%. CONCLUSIONS: Although favorable short-term results can be achieved in patients with rejection-induced severe cardiac dysfunction with immunosuppressive therapy (mainly antilymphocyte antibodies), long-term prognosis seems poor, due to the increased rate of life-threatening infections.

Acute Disease↗
PubMed1994

[An analysis of the factors and phenomena associated with the formation of a spontaneous echo contrast in the left atrium].

INTRODUCTION AND AIMS: To determine the factors related to the formation of spontaneous echo contrast in left atrium. PATIENTS AND METHODS: We have analyzed our series of 1,066 patients undergoing transesophageal echocardiography until December 1991. It was found in left atrium in 387 patients (36%) and was associated with another pathology in 99%. We defined spontaneous echo contrast as mild in 64% and severe in 36%. RESULTS: The prevalence of spontaneous echo contrast was greater in patients with atrial fibrillation (p < 0.001), mitral stenosis (p < 0.001), double mitral lesion (p < 0.001), prosthesis (p < 0.001), embolism (p < 0.05) and a dilated left atrium (left atrial dimension greater than 60 ml) (p < 0.01). The presence of mitral regurgitation made it less frequent (p < 0.05). Thrombi were visualized in 104 patients and they were more frequent in the presence of spontaneous echo contrast. Severe spontaneous echo contrast was significantly more frequent in patients with atrial fibrillation (p < 0.001), mitral stenosis (p < 0.05) and thrombi (p < 0.001). CONCLUSIONS: Spontaneous echo contrast in left atrium is a common finding in transesophageal studies and it is associated with another pathology in 99%. It is more frequent in patients with atrial fibrillation, mitral stenosis, embolism or prosthesis. Left atrial enlargement is one of the more important factors. It is less frequent in patients with mitral regurgitation. Thrombi are less frequent in patients without spontaneous echo contrast. Severe spontaneous echo contrast is significantly associated with mitral stenosis, atrial fibrillation and left atrial thrombi.

Acute Disease↗
PubMed1993

Clinical and hemodynamic predictors of survival in patients aged < 65 years with severe congestive heart failure secondary to ischemic or nonischemic dilated cardiomyopathy.

To identify which clinical or hemodynamic parameters predict survival in patients with end-stage heart failure due to dilated cardiomyopathy, 130 consecutive patients aged < 65 years (mean 46 +/- 13) assessed for heart transplantation from May 1986 to April 1991 were studied. Mean follow-up was 15 +/- 11 months. Left ventricular ejection fraction was 22 +/- 7%. Left ventricular end-diastolic pressure was 27 +/- 9 mm Hg, and cardiac index was 2.2 +/- 0.6 liter/min/m2. Symptom class was IV in 91% of patients and III in 9%. Etiology was ischemic in 40% of patients and idiopathic in 60%. After intensive medical therapy, heart transplantation was considered indicated in 53% of patients, contraindicated in 20% and not indicated in 27%. Transplantation was performed in 36% of patients during follow-up, and 35% died and 29% were alive without transplantation. A comparison, excluding patients with transplantation, was performed between those who were alive and had survived > or = 6 months after assessment, and those who died. On multivariate analysis, the following 3 parameters were independent predictors of prognosis: intravenous inotropic requirement (p < 0.001), maximal, tolerated captopril dose (p = 0.013) and systolic blood pressure (p = 0.003). When patients with transplantation were considered as deaths, stabilization on medical therapy also reached statistical significance (p = 0.009). Classic prognostic markers including ventricular arrhythmias, left ventricular end-diastolic pressure, cardiac index, amiodarone therapy and etiology were not associated with prognosis in this homogeneous population of severely ill patients.

Adolescent↗
PubMed1993

Plasticity of the sensorimotor cortex representation of the reading finger in Braille readers.

We studied the organization of the somatosensory cortex in proficient Braille readers, recording somatosensory evoked potentials (SEPs) in 10 subjects and using transcranial magnetic stimulation (TMS) in five subjects, and compared the results with those of 15 control subjects. Somatosensory evoked potentials were elicited by a focal electrical stimulus to the tip of the index finger and recorded from a contralateral 4 x 4 grid of scalp electrodes centred around C3' and C4'. Transcranial magnetic stimulation, with an 8-shaped coil centred over the same scalp positions, was delivered simultaneously with, and at different intervals after, the finger stimulus. The results of the right index (reading) finger in Braille readers were compared with those of their left index (non-reading) finger and of the right and left index fingers of the control subjects. The scalp areas from which we recorded N20 and P22 components of the SEP with an amplitude of at least 70% of the maximal amplitude recorded in each trial were significantly larger in SEPs evoked from the reading fingers. Detection of the stimulus applied to the reading finger was blocked by TMS delivered over a larger contralateral scalp area and during a longer time window after the stimulus. These experiments suggest that reading Braille is associated with expansion of the sensorimotor cortical representation of the reading finger.

Adult↗
PubMed1993

Pharmacokinetic interaction between high-dose methotrexate and amoxycillin.

A case report of toxicity following concurrent administration of high-dose methotrexate and amoxycillin is presented. A 16-year-old male patient was administered 10 high-dose methotrexate cycles for treatment of a fully malignant osteogenic sarcoma. Methotrexate was administered at a dosage of 8 g/m2 and infused intravenously over a 6-h period. The patient received pre- and posttreatment hydration and sodium bicarbonate for alkalinization of urine. Calcium folinate rescue was performed when appropriate. During the 10th cycle, coadministration of amoxycillin (1 g/6 h, p.o.) resulted in prolonged and marked enhancement of methotrexate serum levels. Pharmacokinetic parameters obtained in cycle 10 indicate significant differences for total plasma clearance, mean residence time, and distribution half-life when compared to those in cycles 1-9. Amoxycillin decreased the renal clearance of methotrexate, probably by competition at the common tubular secretion system and by secondary methotrexate-induced renal impairment. The patient experienced acute and subacute toxicity with renal failure, myelosuppression, mucositis, nausea, vomiting, fever, and dermatologic abnormalities. Patients receiving amoxycillin during methotrexate therapy should be closely monitored to avoid severe toxicity.

Adolescent↗
PubMed1993

[Patients with an acute myocardial infarct treated in a coronary unit or in a general cardiology ward A comparative study].

INTRODUCTION AND OBJECTIVES: Coronary care units have been accepted as the standard location for treatment for patients with acute myocardial infarction. Nevertheless, controversy over their clinical impact, current role and cost-effectiveness still remains. Due to the increased incidence of coronary artery disease in Spain, coronary care units are often full, and patients with acute myocardial infarction must be cared for in a general cardiology ward. METHODS: We have studied the features and results of 420 patients with acute myocardial infarction consecutively admitted to our hospital and compared patients cared for in the coronary care unit (329 [78%]) with those cared for in the cardiology ward (91 [22%]). Admission to cardiology ward or coronary care unit was based on the clinical judgment of emergency room physicians and the bed availability. No differences in age, sex, risks factors, prior history of coronary heart disease, blood pressure on admission, extension and complications of myocardial infarction were found between both groups. RESULTS: The percentage of patients with evolved and non-Q wave acute myocardial infarction, and admission electrocardiogram not suggestive of infarction was significantly higher in ward group (23 versus 2.4%, p < 0.001; 19 versus 11%, p < 0.01; and 43 versus 15%, p < 0.01; respectively). Although patients admitted to the coronary care unit underwent intravenous thrombolysis and coronary artery revascularization procedures in a higher proportion, mortality was similar in both groups (14% for ward patients and 17% for coronary care unit patients). When patients with evolved or non-Q wave infarctions and those with admission electrocardiograms not suggestive of infarction were excluded from the analysis, mortality rates remained similar. Subgroups mortality was in general similar for patients cared for in cardiology ward or in coronary care unit, although patients without shock, with Killip class I or II, and older than 70 years, had a slightly lesser mortality when treated in the Cardiology ward (5 versus 11%, 6 versus 11%, and 14 versus 28%, respectively). By contrast, patients with shock, Killip class III or IV, and electrocardiogram at admission not suggestive of infarction, had a lesser mortality when cared for in coronary care unit. CONCLUSIONS: We conclude that some subgroups of patients with acute myocardial infarction can be, if needed, effective and safely cared for in cardiology ward.

Aged↗
PubMed1993

[Infectious endocarditis due to Q fever. A report of 4 new cases].

Q fever (Coxiella burnetii) is an uncommon cause of culture-negative infective endocarditis. Four cases of Q fever endocarditis diagnosed at our hospital in the last 7 years are reported (8% of all infective endocarditis). Infection involved a prosthetic heart valve in 3 cases (15% of all prosthetic valve endocarditis), and one patient with single ventricle and pulmonary stenosis in the remaining case. Important complications developed in all cases, and 3 patients underwent cardiac surgery. Mortality was 50%. Some diagnostic and therapeutical aspects of this disease are discussed.

Adult↗