Densitometric analysis of GnRH and IBA1 immunocytochemistry in the basal ventromedial hypothalamus of the ewe.

Gonadotropin releasing hormone (GnRH) synthesis and secretion regulates seasonal fertility. In the brain, the distribution of GnRH-positive neurons is diffuse, hindering efforts to monitor variations in its cellular and tissue levels. Here, we aim at assessing GnRH immunoreactivity in nuclei responsible for seasonal fertility regulation (SFR) within the posterior, anterior, and preoptic areas of the basal hypothalamus during estrous in ewes. We detected reaction products in the ventromedial basal hypothalamus in neurons, nerve fibers, non-neuronal immunoreactive bodies, and diffuse interstitial areas. Immunoreactivity correlated with the distribution of the main SFR nuclei in the arcuate, retrochiasmatic, periventricular, medial preoptic, supraoptic, and preoptic areas. By independent component analysis density segmentation and by interferential contrast, we identified GnRH non-neuronal positive bodies as microglial cells encapsulated within a dense halo of reaction products. These GnRH-positive microglial cells were distributed in patches and rows throughout the basal ventromedial hypothalamus, suggesting their role in paracrine or juxtacrine signaling. Moreover, as shown by ionized calcium-binding adaptor molecule 1 (IBA1) immunocytochemistry, the distribution of GnRH reaction products overlapped with the microglial dense reactive zones. Therefore, our findings support the assertion that a combined densitometric analysis of GnRH and IBA1 immunocytochemistry enables activity mapping for monitoring seasonal changes following experimental interventions.

Multisession anodal epidural direct current stimulation of the auditory cortex delays the progression of presbycusis in the Wistar rat.

Presbycusis or age-related hearing loss (ARHL) is one of the most prevalent chronic health problems facing aging populations. Along the auditory pathway, the stations involved in transmission and processing, function as a system of interconnected feedback loops. Regulating hierarchically auditory processing, auditory cortex (AC) neuromodulation can, accordingly, activate both peripheral and central plasticity after hearing loss. However, previous ARHL-prevention interventions have mainly focused on preserving the structural and functional integrity of the inner ear, overlooking the central auditory system. In this study, using an animal model of spontaneous ARHL, we aim at assessing the effects of multisession epidural direct current stimulation of the AC through stereotaxic implantation of a 1-mm silver ball anode in Wistar rats. Consisting of 7 sessions (0.1 mA/10 min), on alternate days, in awake animals, our stimulation protocol was applied at the onset of hearing loss (threshold shift detection at 16 months). Click- and pure-tone auditory brainstem responses (ABRs) were analyzed in two animal groups, namely electrically stimulated (ES) and non-stimulated (NES) sham controls, comparing recordings at 18 months of age. At 18 months, NES animals showed significantly increased threshold shifts, decreased wave amplitudes, and increased wave latencies after click and tonal ABRs, reflecting a significant, spontaneous ARHL evolution. Conversely, in ES animals, no significant differences were detected in any of these parameters when comparing 16 and 18 months ABRs, indicating a delay in ARHL progression. Electrode placement in the auditory cortex was accurate, and the stimulation did not cause significant damage, as shown by the limited presence of superficial reactive microglial cells after IBA1 immunostaining. In conclusion, multisession DC stimulation of the AC has a protective effect on auditory function, delaying the progression of presbycusis.

Reward and fictive prediction error signals in ventral striatum: asymmetry between factual and counterfactual processing.

Reward prediction error, the difference between the expected and obtained reward, is known to act as a reinforcement learning neural signal. In the current study, we propose a model fitting approach that combines behavioral and neural data to fit computational models of reinforcement learning. Briefly, we penalized subject-specific fitted parameters that moved away too far from the group median, except when that deviation led to an improvement in the model's fit to neural responses. By means of a probabilistic monetary learning task and fMRI, we compared our approach with standard model fitting methods. Q-learning outperformed actor-critic at both behavioral and neural level, although the inclusion of neuroimaging data into model fitting improved the fit of actor-critic models. We observed both action-value and state-value prediction error signals in the striatum, while standard model fitting approaches failed to capture state-value signals. Finally, left ventral striatum correlated with reward prediction error while right ventral striatum with fictive prediction error, suggesting a functional hemispheric asymmetry regarding prediction-error driven learning.

Cross-modal reaction of auditory and visual cortices after long-term bilateral hearing deprivation in the rat.

Visual cortex (VC) over-activation analysed by evoked responses has been demonstrated in congenital deafness and after long-term acquired hearing loss in humans. However, permanent hearing deprivation has not yet been explored in animal models. Thus, the present study aimed to examine functional and molecular changes underlying the visual and auditory cross-modal reaction. For such purpose, we analysed cortical visual evoked potentials (VEPs) and the gene expression (RT-qPCR) of a set of markers for neuronal activation (c-Fos) and activity-dependent homeostatic compensation (Arc/Arg3.1). To determine the state of excitation and inhibition, we performed RT-qPCR and quantitative immunocytochemistry for excitatory (receptor subunits GluA2/3) and inhibitory (GABAA-α1, GABAB-R2, GAD65/67 and parvalbumin-PV) markers. VC over-activation was demonstrated by a significant increase in VEPs wave N1 and by up-regulation of the activity-dependent early genes c-Fos and Arc/Arg3.1 (thus confirming, by RT-qPCR, our previously published immunocytochemical results). GluA2 gene and protein expression were significantly increased in the auditory cortex (AC), particularly in layers 2/3 pyramidal neurons, but inhibitory markers (GAD65/67 and PV-GABA interneurons) were also significantly upregulated in the AC, indicating a concurrent increase in inhibition. Therefore, after permanent hearing loss in the rat, the VC is not only over-activated but also potentially balanced by homeostatic regulation, while excitatory and inhibitory markers remain imbalanced in the AC, most likely resulting from changes in horizontal intermodal regulation.

APACHE II score for critically ill patients with a solid tumor: A reclassification study. / Escala APACHE II para pacientes críticos con cáncer sólido. Estudio de reclasificación.

OBJECTIVE: To improve the accuracy of the Acute Physiology and Chronic Health Evaluation (APACHE) II model for predicting hospital mortality in critically ill cancer patients. MATERIALS AND METHODS: This was a prospective cohort study of 522 patients admitted to ICU with a solid tumor. We developed the "APACHE II score for critically ill patients with a solid tumor" (APACHE IICCP score), in which typical variables of critically ill cancer patients were added to general APACHE II score. Calibration and discrimination were evaluated by Hosmer-Lemeshow test (H-L) and area under receiver operating characteristic curve (AROC), respectively. The improvement in predicting hospital mortality with the new model was assessed using a reclassification analysis by integrated discrimination improvement (IDI), net reclassification improvement (NRI; cut-off point of 20% in risk of death) and quantitative NRI (qNRI). RESULTS: The hospital mortality rate was 13%. Discrimination was superior for APACHE IICCP score (AROC=0.91 [95% CI 0.87-0.94; P<.0001]) compared to general APACHE II score (AROC=0.62 [95% CI 0.54-0.70; P=.002]). Calibration was better using APACHE IICCP score (H-L; P=.267 vs. P=.001). In reclassification analysis, an improved mortality prediction was observed with APACHE IICCP score (IDI=0.2994 [P<.0001]; total qNRI=134.3% [95% CI 108.8-159.8%; P<.0001]; total NRI=41.5% [95% CI 23.7-59.3%; P<.0001]). CONCLUSIONS: The performance of APACHE IICCP score was superior to that observed for general APACHE II score in predicting mortality in critically ill patients with a solid tumor. Other studies validating this new predictive model are required.

c-Fos and Arc/Arg3.1 expression in auditory and visual cortices after hearing loss: Evidence of sensory crossmodal reorganization in adult rats.

Cross-modal reorganization in the auditory and visual cortices has been reported after hearing and visual deficits mostly during the developmental period, possibly underlying sensory compensation mechanisms. However, there are very few data on the existence or nature and timeline of such reorganization events during sensory deficits in adulthood. In this study, we assessed long-term changes in activity-dependent immediate early genes c-Fos and Arc/Arg3.1 in auditory and neighboring visual cortical areas after bilateral deafness in young adult rats. Specifically, we analyzed qualitatively and quantitatively c-Fos and Arc/Arg3.1 immunoreactivity at 15 and 90 days after cochlea removal. We report extensive, global loss of c-Fos and Arc/Arg3.1 immunoreactive neurons in the auditory cortex 15 days after permanent auditory deprivation in adult rats, which is partly reversed 90 days after deafness. Simultaneously, the number and labeling intensity of c-Fos- and Arc/Arg3.1-immunoreactive neurons progressively increase in neighboring visual cortical areas from 2 weeks after deafness and these changes stabilize three months after inducing the cochlear lesion. These findings support plastic, compensatory, long-term changes in activity in the auditory and visual cortices after auditory deprivation in the adult rats. Further studies may clarify whether those changes result in perceptual potentiation of visual drives on auditory regions of the adult cortex.

Dorsal nucleus of the lateral lemniscus in the rat: concentric organization and tonotopic projection to the inferior colliculus.

A basic principle of organization in auditory centers is the topographic-tonotopic order. Whether this applies to the dorsal nucleus of the lateral lemniscus (DNLL), however, is still debated. To clarify this problem, we have utilized the neuroanatomical tracers horseradish peroxidase (HRP) and biotinylated dextran (BD) injected into different regions of the central nucleus of the inferior colliculus (CNIC) in the rat. After large injections of HRP that included most of the CNIC, retrogradely labelled neurons were found all across the ipsi- and contralateral DNLL, showing that all parts of this nucleus innervate the CNIC bilaterally. More neurons were seen consistently on the side contralateral to the injection site. Labelled fibers, however, were abundant ipsilaterally, but scarce in the contralateral DNLL. Single, small injections of HRP or BD into the CNIC resulted in labelling in restricted areas of the ipsi- and contralateral DNLL. In coronal sections, the neurons and fibers labelled in the ipsilateral DNLL formed a well-defined, ring-shaped structure made of dendrites and axons oriented parallel to each other, which we termed "annular band." The observation of serial sections revealed that the annular band seen in any individual section represents a slice through a more or less complete three-dimensional, hollow, ovoid structure oriented rostrocaudally. The position and diameter of the annular band changed as the injection site was shifted along the tonotopic axis of the CNIC. Single injections placed in the ventromedial, high-frequency region of the CNIC produced a large annular band along the periphery of the DNLL. After injections placed in progressively more dorsolateral, lower-frequency regions of the CNIC, the annular band became smaller in diameter and occupied a successively more central position in the DNLL. Double injections along the tonotopic axis of the CNIC resulted in two roughly concentric annular bands. The labelled neurons and fibers in the contralateral DNLL systematically occupied a position symmetric to the annular band seen ipsilaterally. These findings indicate that the rat DNLL is primarily composed of neurons with flattened dendritic arbors and flattened fields of terminal fibers. These two elements intermingle, forming concentric layers around the geometric center of the nucleus. The axons of neurons within corresponding layers on the two sides converge onto the CNIC of both sides in a strict topographic fashion: the peripheral layers project to the ventromedial, high-frequency region of the CNIC, and the central layers project to the dorsolateral, low-frequency region. These results suggest that the concentric arrangement of the DNLL is the substrate of its tonotopic organization.

Rapid westernization of children's blood cholesterol in 3 countries: evidence for nutrient-gene interactions?

The aim of this study was to examine potential factors that modify blood cholesterol among children in countries in which dietary and lifestyle habits are becoming westernized. Population data on serum total and lipoprotein cholesterol, anthropometric indexes, and dietary intake were reviewed and compared for children aged 1-18 y from Japan, Spain, and the United States. The data show that total serum cholesterol in Japanese and Spanish children recently exceeded the 75th percentile for US children, primarily reflecting LDL cholesterol, although both LDL and HDL cholesterol contributed. Adiposity indexes do not explain the trends observed. Total and saturated fat intakes increased substantially in both Japan and Spain but in Japan are still lower than intakes in the United States. The Hegsted equation was used to relate differences in serum cholesterol to dietary fat intake. Changes in total serum cholesterol followed established dietary correlations among children in Spain, but not in Japan. Serum cholesterol in Japanese children was predicted to be 0.20-0.32 mmol/L lower than in US children; actual concentrations were considerably higher. These results suggest that a rapid westernization of children's blood cholesterol concentrations has occurred in Japan and Spain. Changes in fat intake predict changes in blood cholesterol in Spain, but not in Japan. Differences in genetic response to diet in certain populations, such as the Japanese, may explain higher blood cholesterol concentrations with lower fat intakes compared with the United States.

Severe inherited "homozygous" protein C deficiency in a newborn infant.

A relapsing clinical syndrome of skin lesions and disseminated intravascular coagulation (DIC) that showed remission with the infusion of fresh frozen plasma is described in a newborn infant with homozygous deficiency of protein C antigen. This patient presented since birth a recurrent clinical picture of DIC and ecchymotic skin lesions that resembled typical ecchymosis except for the fact that they showed immediate improvement with the administration of fresh frozen plasma. Using an enzyme linked immunosorbent assay method, the determination of protein C antigen levels in the patient, without ingestion of coumarin drugs, showed very low values (less than 1%). No other deficiencies in the vitamin-K-dependent factors or in antithrombin III, antiplasmin, and plasminogen were found. Seven relatives of the infant had heterozygous deficiency in protein C antigen (values between 40-55%), without clinical history of venous thrombosis. The pedigree analysis of this family suggests an autosomal recessive pattern of inheritance for the clinical phenotype, although an autosomal dominant pattern has been postulated until now in other reported families. We conclude that our patient has a homozygous deficiency in protein C and this homozygous state may be compatible with survival beyond the neonatal period.

Atrioventricular nodal dysfunction in patients with atrial septal defect. Abnormalities of conduction and reciprocal rhythms.

Electrophysiologic studies were performed in 17 unselected patients (mean age, 20 years) with atrial septal defect (ASD) of the ostium secundum type. In nine (52.9 percent) signs were found of atrioventricular (A-V) nodal dysfunction, in seven (41.1 percent) prolonged A-H interval, and in three (17.6 percent) prolonged effective refractory period of A-V node and in five (29.4 percent) A-V nodal tachycardia and reentry. Three of the four cases showed anterograde conduction (Ae-H interval) faster than retrograde conduction (H-A3 interval) during the tachycardia. In one patient with reentry a similar phenomenon was observed. In the remaining patient the conduction time was reversed (Ae-H longer than H-Ae). In two patients infrahisian and intrahisian block (first and second degree) with persistence of the tachycardia was observed. Patent or latent abnormalities in A-V node function are a frequent finding in patients with ASD. In the sinus node, any kind of significant abnormality can be found.

Centralized transfusion service: a novel approach to the delivery of transfusion services.

The development and expansion of the CTS in Pittsburgh shows the feasibility of this transfusion medicine delivery system. Few of the changes driven by health care reform both improve patient care and reduce costs. When properly implemented, a CTS achieves these objectives, benefits the community as a whole, and enhances the role of transfusion medicine specialists and the blood center in the region.

Cardiac size and function in Paget's disease of bone.

We performed non-invasive assessment of cardiac size and function by clinical criteria, standard electrocardiography, chest X-ray, systolic time intervals and echo-cardiography in 27 patients with Paget's disease of bone and in 20 control subjects. The patients were divided into two groups on the basis of the degree of skeletal involvement (less than 15% in Group I and greater than 15% in Group II). No differences in heart size parameters of left ventricular performance were noted between Group I and controls. Cardiomegaly, increased left ventricular diastolic dimension and increased left ventricular mass indicative of ventricular hypertrophy were found in Group II compared to control subjects. In addition, patients with more extensive skeletal involvement had signs of depressed myocardial contractility, increased left ventricular volumes in diastole and systole and enlarged stroke volume, with no differences in echographic cardiac output compared to Group I and controls. The findings show an above normal incidence of cardiac enlargement and disturbed left ventricular performance in patients with Paget's disease and osseous lesions in greater than 15% of skeleton. The clinical implications of the altered cardiac function in patients with Paget's disease are briefly discussed.

Biotransformation of n-hexadecane by cell suspension cultures of Cinchona robusta and Dioscorea composita.

This manuscript evaluates the phytotoxicity and biotransformation of n-hexadecane as well as peroxidase activity and cytochrome P450 concentration in microsomes for cell suspension cultures of Cinchona robusta and Dioscorea composita. Phytotoxicity was evaluated based on viability and growth. Cell cultures were exposed to a 2 and 4% (v/v) dose of n-hexadecane. The biotransformation of n-hexadecane was determined based on labeled recovery in polar, nonpolar, and cell residue fractions after cell culture extraction during exponential cell growth phase and stationary phase. Differences were observed in accumulation of label during cell growth phase and stationary phase for the cells of the two plants. Differences also were observed between phases for label in polar and nonpolar fractions. Thin-layer chromatography determined labeled intermediates and some were identified. The activity of peroxidase and concentration of cytochrome P450 was lower in C. robusta than in controls and greater in D. composita than in controls. In vitro biotransformation was not successful.

Widespread posttracheostomy atypia simulating squamous cell carcinoma. A case report.

Squamous atypia appears as a benign posttracheostomy phenomenon occasionally mistaken for squamous carcinoma. Most often seen are clumps of atypical metaplastic cells with irregular nuclear rims and chromatin that can be either finely dispersed or coarsely clumped. The cytoplasm is thick, and the cytoplasmic membrane is sharply outlined. We describe a case of squamous atypia occurring in a patient 30 years after laryngectomy. The atypia was so extreme that segmental bronchoscopy was performed to search for occult carcinoma. No carcinoma was found, but numerous atypical cells were found in the segmental bronchi sampled by endobronchial brushings. This finding indicates that posttracheostomy atypia can involve respiratory mucosa distant from the tracheal (stump) mucosa. Sputum and bronchoscopic samples received from patients with tracheostomies should be screened with a clear understanding of the morphologically distinct atypia encountered.

[Combination of quinidine and verapamil in auricular fibrillation]. / Combinación de quinidina y verapamil en la fibrilación auricular.

The efficacy of the association of verapamil plus quinidine in 70 patients with atrial fibrillation, 64 of them after having cardiac surgery, was assessed. Oral dosage ranged from 825 mg to 1,100 mg for quinidine polygalacturonate and 240 mg to 320 mg for verapamil. All patients but two reached a good control of heart rate (mean heart rate less than 110 beats/min) while arrhythmia persisted. Sixty patients (85.7%) reverted to normal sinus rhythm in a period of 2.4 +/- 1.5 days (mean +/- SD). According to the atrial fibrillation duration three subsets of patients with different conversion rates to sinus rhythm were established (p less than 0.01): group A (lasting from 1 day to 3 months) 31/39 (96%); group B (lasting 3 to 6 months) 18/21 (85.7%) and group C (lasting 6 to 12 months) 5/10 (50%) (p less than 0.01). Plasma quinidine levels were maintained at either near to or therapeutic range (2.6 +/- 0.94 micrograms/ml). Adverse effects comprised one ventricular arrhythmia-induced syncope (quinidine syncope) and two cases of systemic hypotension. Quinidine-verapamil association is a good alternative in the treatment of atrial fibrillation, particularly in those of recent onset, according to the high rates of conversion to normal sinus rhythm, affording control of heart rate while atrial fibrillation persists. Adverse reactions did not differ in severity from those observed with quinidine monotherapy.

[The Fuenlabrada study: arterial pressure in children and adolescents]. / Estudio de Fuenlabrada: tensión arterial en niños y adolescentes.

Blood pressure was studied in 2,153 healthy children of both sexes, from 0 to 18 years of age; 1,115 were males and 1,038 females. Systolic and diastolic blood pressures were measured in the sitting position by the auscultatory method on the right arm with a mercury sphygmomanometer using an appropriate cuff size. Systolic blood pressure was measured on the first sound and diastolic blood pressure in the fourth phase of Korotkoff. In children younger than 3 years blood pressure was measured in the decubitus supine position using the Doppler technique. There were no significant differences in mean systolic and diastolic blood pressure in both sexes. But the percentage of systolic blood pressure greater than or equal to 130 mmHg was higher in males than females (p less than or equal to 0.01). 8.4% of the total population had systolic blood pressure greater than or equal to 130 mmHg, and 1.3% had diastolic blood pressure greater than or equal to 90 mmHg. The annual increase rates of systolic and diastolic blood pressure were 2.31/0.94 mmHg in males and 2/0.97 mmHg in females. Children with blood pressure greater than or equal to the 95th percentile had a higher prevalence of hypertriglyceridemia and obesity. 54% of the variation in systolic blood pressure was explained by the association of weight, subscapular skinfold, body mass index and C-HDL. 30% of the variation in diastolic blood pressure was explained by the association of weight, obesity index, subscapular skinfold and C-HDL.

[The Fuenlabrada study: a familial aggregation of ischemic cardiopathy and cardiovascular risk factors]. / Estudio de Fuenlabrada: agregación familiar de la cardiopatía isquémica y de los factores de riesgo cardiovascular.

UNLABELLED: Familial aggregation of coronary heart disease (CHD) and coronary risk factors (CRF) were evaluated by clinical history in adult relatives of children surveyed for CRF. Population was divided into two groups: Group I included 2,153 children without parental history of CHD. Group II included 266 children of 112 families with parental history of early CHD (before 56 years). In 105 cases the patients were the fathers and in 7 cases the mothers. All the patients were admitted to a coronary care unit. Familial aggregation of CHD was 9.7 times more frequent in paternal families of group II (p less than or equal to 0.0001) than in group I; there was no differences in maternal families. Higher prevalence of hyperlipidaemia, blood pressure hypertension, smoking habits, diabetes and obesity in fathers of group II was observed. Children in group II showed increased levels of C-LDL and decreased levels of C-HDL compared with those of group I. The prevalence of CRF was also significantly higher in children of group II, although in the 33% of the children of group II no CRF was detected. CONCLUSION: a substantial proportion, but not all cases, of familial aggregation of CHD could be explained by known CRF.

[The return to work after coronary revascularization]. / Retorno al trabajo después de la revascularización coronaria.

INTRODUCTION: Work resumption after a therapeutical intervention has been considered as a sensitive indicator of its success. There are some reports analyzing working status after coronary artery revascularization in western countries. However, to our knowledge, similar studies have not been published in Spain. PATIENTS AND METHODS: We studied 210 patients after coronary artery revascularization surgery or percutaneous transluminal coronary angioplasty. Exclusion criteria were age of 65 or more years and female sex gender (n = 64). RESULTS: Working patient rate before and after coronary revascularization was respectively 63.2% and 28.9% for surgery, and 57.1% and 41.4% for percutaneous angioplasty (p = 0.11). None of the former inactive patients, with the exception of one in the surgery group, went back to work after the revascularization procedure. Asymptomatic patients after percutaneous angioplasty had a higher postprocedure working rate than symptomatic ones (58.1% vs 11.1%, p < 0.0001). Patients in the surgery group did not show this relation (30% vs 25%, p = 0.69). CONCLUSIONS: Surprisingly, coronary artery revascularization interventions, mainly coronary surgery, seems to behave in our environment as important determinants of working cessation.

[Fuenlabrada study: lipid and lipoprotein levels in children and adolescents associated with ischemic cardiopathy prevalence among their relatives]. / Estudio de Fuenlabrada: asociación entre los niveles de lípidos y lipoproteínas en niños y adolescentes con la prevalencia de cardiopatía isquémica en sus familiares.

The prevalence of coronary heart disease (CHD) was studied in parents and grandparents of 2,419 children surveyed for lipid levels. Children and their families were divided into 3 groups depending on the level of each lipid and lipoprotein studied in children: high greater than or equal to 95 percentile (p), medium 5-95 p, and low less than 5 p. Total cholesterol (Chol) and triglycerides (TG) were determined by enzymatic techniques in autoanalyzer. C-HDL was determined by precipitation method. C-LDL and C-VLDL were obtained by Friedewald-Fredrickson's equation. The prevalence of CHD in parents and grandparents was ascertained from clinical history. Fathers of children in the high groups of Chol, TG, C-LDL/C-HDL, and low group of C-HDL had increased prevalence of CHD compared with those of the low groups of Chol, TG, C-LDL, C-LDL/C-HDL and high group of C-HDL. The strongest association was with C-HDL. Maternal and paternal grandfathers of children in the high groups of Chol had also increased prevalence of CHD compared with those of low group of Chol. There was no association with any other variable. The association was not significant neither in mothers nor in maternal and paternal grandmothers. Childhood lipid and lipoprotein levels could identify families at elevated risk for CHD.

[Free thrombus in the left atrium associated with mitral stenosis. Diagnostic and therapeutic aspects. Apropos of a case]. / Trombo libre en aurícula izquierda asociado a estenosis mitral. Aspectos diagnósticos y terapéuticos. A propósito de un caso.

A patient with a history of transient cerebral ischemic episodes had two-dimensional echocardiographic findings consistent with mitral stenosis associated with a spherical free-floating left atrial thrombus. The patient was operated on in the next few days, performing a mitral commissurotomy, and the left atrial thrombus was removed, without intra- or postoperative complications. The patient was discharged from the hospital on an antiplatelet drug regimen. Free-floating left atrial thrombi are a very rare finding with an easy echocardiographic diagnosis. Prompt surgical treatment is mandatory because the risk of systemic embolization and sudden death are inherent in this entity.