[Comparative study of treatment with quinupristin-dalfopristin alone or in combination with gentamicin, teicoplanin, imipenem or levofloxacin in experimental endocarditis due to a multidrug-resistant Enterococcus faecium]. / Comparacion de la eficacia de quinupristina-dalfopristina en monoterapia y combinada con gentamicina, teicoplanina, imipenem o levofloxacino en un modelo experimental de endocarditis por Enterococcus faecium multirresistente.

The incidence of multidrug-resistant Enterococcus faecium is increasing despite advances in antibacterial therapy. Thus, new antibiotics are required to treat hospital- or community-acquired infections caused by these multidrug-resistant organisms. The aim of this study was to compare the therapeutic efficacy of quinupristin-dalfopristin (QD) alone, or in combination with gentamicin (G), teicoplanin (T), imipenem (I) or levofloxacin (L) against a strain of multidrug-resistant E. faecium in an experimental model of aortic valve endocarditis in rabbits. The study group consisted of 28 control animals. Eighty-two animals were treated with one of the following antibiotic regimens: G1: 18 animals QD (30 mg/kg/8 h); G2: 18 animals QD+G (6 mg/kg/12 h); G3: 16 animals QD+T (20 mg/kg/12 h); G4: 14 animals QD+I (60 mg/kg/8 h); and G5: 16 animals QD+L (20 mg/kg/12 h). The response to therapy was determined by the comparison of the number of CFU/g of E. faecium in each vegetation. In vitro, time-kill studies looking for synergy for the combinations that showed better efficacy in vivo were done. The sensitivity of the strain was intermediate to QD, resistant to T and I, and sensitive to L. There was no high-level resistance to G. QD alone revealed a significant decrease (p <0.001) in the CFU/g in the control group (9.49 vs. 7.31). There were no differences in the average of CFU/g between the QD alone (G1), QD+G (G2) and QD+T (G3) groups. These three groups revealed a significant difference in decrease of CFU/g respect of the group control (p <0.001). There were no differences in the average of CFU/g between QD+I (G4) and QD+T (G5). These two groups revealed the greatest decrease in average CFU/g (G4: 4.38 and G5: 4.04) with differences respect of the group control (p <0.0001) and respect of the groups G1, G2 and G3 (p <0.001). We did not detect any alteration of MIC from QD in the course of the treatment for either of the final isolations. Only the time kill corresponding to concentrations of I 32 mg/l (0.25 x MIC) and QD 1 mg/l (0.25 x MIC presents a descending slope in the curve at 4 and 8 h, suggesting an early synergy phenomenon, which was lost after 8 h. In light of these results, the combination QD with I and L may be considered suitable alternatives for the treatment of multiresistant E. faecium.

Comparación de la eficacia de quinupristina-dalfopristina en monoterapia y combinada con gentamicina, teicoplanina, imipenem o levofloxacino en un modelo experimental de endocarditis por Enterococcus faecium multirresistente / Comparative study of treatment with quinupristin-dalfopristin alone or in combination with gentamicin, teicoplanin, imipenem or levofloxacin in experimental endocarditis due to a multidrug-resistant Enterococcus faecium

La incidencia de infecciones por Enterococcus faecium multirresistentes va aumentando a pesar de los avances que se han producido en antibioticoterapia.Por ello, se necesitan nuevos antibióticos para tratar las infecciones nosocomiales o comunitarias causadas por este microorganismo.El objetivo principal del presente estudio fue comparar la eficacia de quinupristina-dalfopristina (QD), sola o combinada con gentamicina(G), teicoplanina (T), imipenem (I) o levofloxacino (L), en un modelo de endocarditis experimental en conejos por E. faecium multirresistente.Se utilizaron 110 animales, 28 como grupo control y 82 como grupos terapéuticos, que fueron G1: 18 animales con QD (30mg/kg/8 h); G2: 18 con QD+G (6 mg/kg/12 h); G3: 16 con QD+T (20 mg/kg/12 h); G4: 14 con QD+I (60 mg/kg/8 h); y G5: 16 con QD+L(20 mg/kg/12 h). Se valoró la respuesta terapéutica comparando la concentración de E. faecium en las vegetaciones cardiacas expresada comolog10 de las unidades formadoras de colonias por gramo de tejido (UFC/g). Se realizaron pruebas de cinética de letalidad bacteriana paralas asociaciones que mostraron mejor comportamiento in vivo: QD + I y QD + L. El patrón de sensibilidad de la cepa utilizada fue: sensiblepara L, intermedia para QD, resistente para T e I, y sin resistencia de alto grado para G. El tratamiento con QD logró una reducción significativa(p <0.001) en las UFC/g respecto al grupo control (9,49 frente a 7,31). No hubo diferencias significativas entre los grupos G1 (QDsola), G2 (QD + G) y G3 (QD + T), consiguiendo estos tres grupos una redución significativa respecto del grupo control (p <0.001). No hubodiferencias entre G4 (QD + I) y G5 (QD + L). Estos dos grupos se mostraron como los más eficaces en reducir la media de UFC/g en lasvegetaciones cardiacas (G4: 4,38 y G5: 4,04), con p <0.0001 respecto al grupo control y p <0.001 respecto a G1, G2 y G3. No se detectóningún cambio en la CMI de QD durante el tratamiento. Sólo la curva de letalidad correspondiente a la concentración de I de 32 mg/l (0,25x CMI) con QD 1 mg/l (0,25 x CMI) presentó una curva descendente a las 4 y 8 horas, sugiriendo una sinergia precoz que se perdió a las 8 horas.A la vista de estos resultados, la combinación de QD con I o L podría considerarse como alternativa terapéutica en la endocarditis porE. faecium multirresistente

The incidence of multidrug-resistant Enterococcus faecium is increasing despite advances in antibacterial therapy. Thus, new antibiotics arerequired to treat hospital- or community-acquired infections caused by these multidrug-resistant organisms. The aim of this study was tocompare the therapeutic efficacy of quinupristin-dalfopristin (QD) alone, or in combination with gentamicin (G), teicoplanin (T), imipenem(I) or levofloxacin (L) against a strain of multidrug-resistant E. faecium in an experimental model of aortic valve endocarditis in rabbits. Thestudy group consisted of 28 control animals. Eighty-two animals were treated with one of the following antibiotic regimens: G1: 18 animalsQD (30 mg/kg/8 h); G2: 18 animals QD+G (6 mg/kg/12 h); G3: 16 animals QD+T (20 mg/kg/12 h); G4: 14 animals QD+I (60 mg/kg/8 h);and G5: 16 animals QD+L (20 mg/kg/12 h). The response to therapy was determined by the comparison of the number of CFU/g of E. faeciumin each vegetation. In vitro, time-kill studies looking for synergy for the combinations that showed better efficacy in vivo were done.The sensitivity of the strain was intermediate to QD, resistant to T and I, and sensitive to L. There was no high-level resistance to G. QD alonerevealed a significant decrease (p <0.001) in the CFU/g in the control group (9.49 vs. 7.31). There were no differences in the average of CFU/gbetween the QD alone (G1), QD+G (G2) and QD+T (G3) groups. These three groups revealed a significant difference in decrease of CFU/grespect of the group control (p <0.001). There were no differences in the average of CFU/g between QD+I (G4) and QD+T (G5). These twogroups revealed the greatest decrease in average CFU/g (G4: 4.38 and G5: 4.04) with differences respect of the group control (p <0.0001)and respect of the groups G1, G2 and G3 (p <0.001). We did not detect any alteration of MIC from QD in the course of the treatment for eitherof the final isolations. Only the time kill corresponding to concentrations of I 32 mg/l (0.25 x MIC) and QD 1 mg/l (0.25 x MIC presents adescending slope in the curve at 4 and 8 h, suggesting an early synergy phenomenon, which was lost after 8 h. In light of these results, thecombination QD with I and L may be considered suitable alternatives for the treatment of multiresistant E. faecium

Comparative study of treatment with penicillin, ceftriaxone, trovafloxacin, quinupristin-dalfopristin and vancomycin in experimental endocarditis due to penicillin- and ceftriaxone-resistant Streptococcus pneumoniae.

The efficacy of different antibiotics was compared in an experimental model of aortic valve endocarditis in rabbits, using a serotype 19 strain of Streptococcus pneumoniae resistant to penicillin (MIC 12 mg/L) and ceftriaxone (MIC 12 mg/L). The results were compared with those of a control group, which received no treatment. One hundred and nineteen animals were treated with one of the following antibiotic regimens: im procaine penicillin G at a dosage of 300,000 U/kg weight/12 h (16 animals); iv trovafloxacin, 13.3 mg/kg/12 h (31 animals); iv ceftriaxone, 75 mg/kg/24 h (21 animals); iv vancomycin, 20 mg/kg/12 h (15 animals) and im quinupristin-dalfopristin, 30 mg/kg/8 h (20 animals). All the antibiotics used in this study proved to be efficient in reducing numbers of S. pneumoniae and in increasing the percentage of aortic vegetations that were rendered sterile compared with the control group. Penicillin at the dosage used in our study was capable of achieving serum concentrations two or three times greater than the MIC, thus demonstrating its effectiveness as an antibiotic for this endocarditis model. No significant difference was observed between the effects of vancomycin, quinupristin-dalfopristin and penicillin. Vancomycin proved to be more efficient than trovofloxacin in reducing the bacterial load and increasing the numbers sterilized. There was also a tendency for this antibiotic to be more effective than ceftriaxone in reducing the bacterial load of the vegetations. There was a statistically significant correlation between the weight of the vegetations and their bacterial load. In the light of these results, vancomycin and quinupristin-dalfopristin may be considered suitable alternatives to penicillin for the treatment of penicillin-resistant S. pneumoniae endocarditis.

Revisión y perspectivas actuales de la endocarditis por neumococo / Review and current perspectives on endocarditis due to pneumococci

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[The anomalous origin of the left common coronary trunk in the right sinus of Valsalva with an interarterial path. Apropos a case]. / Origen anómalo del tronco coronario común izquierdo en el seno de Valsalva derecho con trayecto interarterial. A propósito de un caso.

We present the case of an old patient with coronary artery disease and two previous myocardial infarctions, admitted to the hospital by syncopal episodes, in which the coronariographic study showed the ectopic origin of the left main coronary artery in the right sinus of Valsalva with anomalous course between the aortic and pulmonary arteries. In this case the initial coronariographic diagnosis and the therapeutical attitude (initially aggressive only in cases of interarterial course) was confirmed by mean of transesophageal echocardiography, showing a better topographical definition of the ectopic vessel aberrant course, although due to the high degree of left ventricular disfunction and the diffuse disease of distal vessels in this patient, CABG surgery was avoided. The angiographic feature is described and the transesophageal approach is remarked as a complementary diagnostic tool in the correct definition of the anomalous course.

[Mitral valve insufficiency in acute myocardial infarction. Assessment with pulsed and coded Doppler color]. / Insuficiencia mitral en el infarto agudo del miocardio. Valoración con Doppler pulsado y codificado en color.

We studied 108 patients who sustained an acute myocardial infarction (AMI) by means of echocardiography, pulsed doppler (PD) and Doppler color flow imaging (CD). We evaluate the presence of mitral regurgitation (MR) and it relationship to the site of the AMI and also to the ventricular function. The incidence of MR was 50.92%, (55/108), it was detected in higher percentage when the AMI was inferior (61.8%) than when anterior (39.6%). The correlation with the ejection fraction (EF) was only significative when the AMI was anterior. The incidence of MR was 57.1% when the EF was below 25%. CD had better diagnostic capabilities independently of the site of the AMI, (48% vs 32.1% when the AMI was anterior and 76.1% vs 52.6% when it was inferior).

[Clinico-pathologic manifestations of ruptured aneurysm of the sinus of Valsalva]. / Manifestaciones clínico-patológicas de los aneurismas rotos del seno de Valsalva.

The clinical files from the National Institute of Cardiology "Ignacio Chávez" were reviewed, we found 26 corroborated cases of ruptured aneurysms Valsalva's sinus. There is predominance of the male sex in proportion 3:1 and the median age when the diagnosis was made was 22 years. 77% of these cases were in N.Y.H.A. clinical class I or II and the main symptom was dyspnoea on exertion. On the physical examination a continuous murmur or sistolo-diastolic murmur was heard over precordium in 92% of the cases and a hyperkinetic circulatory regimen. Only in 23% of these patients the diagnosis was suspected and the more common confusion was with the V.S.D. associated with aortic incompetence. On the E.K.G. we found data with volumetric overload of the right heart in 15 cases. The hemodynamic study confirmed the diagnosis only in 60%. The aortic valve was substituted for associated incompetence in 12 cases and the pathological study revealed fibromixoid degeneration in 9 cases and only fibrosis in the remaining 3. The sinus of Valsalva more affected was the right coronary and the chamber where the rupture was more frequent was the right ventricle in 73% of the cases. We conclude that the ruptured aneurysms of the Valsalva's sinus is rather frequent among the congenital heart diseases and has particular clinical data and special features in making a precise diagnosis.

[Left aortic arch without a circumflex segment and a right descending aorta: a hypothetical case and a real example]. / Arco aórtico izquierdo sin segmento circunflejo y aorta descendente derecha: de un caso hipotético a un ejemplo real.

We studied a case of a patent left ductus arteriosus, with a left aortic arch connected to a right descending aorta without an aortic circumflex (retroesophageal) segment. We believe this is the first world-published example of this--so far--hypothetical anomaly, included in Kirkling and Edwards classification of vascular rings. The case was a 27-year-old deaf-mute female patient with a patent left ductus arteriosus, with important left to right shunt and moderate pulmonary arterial hypertension who underwent a successful closing surgical procedure. In the aortographic study a left (normal) aortic arch was seen, which after giving off a large left ductus arteriosus, crossed to the right and connected to a right descending aorta. In the upper part of the thorax the esophagus and trachea were displaced to the right by the left aortic arch. The esophagus in the middle and the upper inferior parts of the thorax was also displaced to the right by the descending right aortic segment. Complete vascular ring was not evident. The case--although without clinical importance--reinforces the pathogenic concept of the Rathke diagram of a complete double aortic primitive arch originating the pulmonary and supraaortic vascular structures which are formed by the obliteration or disappearance of particular segments of the structure. This knowledge explains the embryogenesis of these complex anomalies. Our case is believed to be formed by the very early disappearance of a frontal portion of the primitive left dorsal aorta.

[Value of the DI and AVL leads in the diagnosis of infarction of the right ventricle]. / Utilidad de las derivaciones DI y AVL en el diagnóstico del infarto del ventrículo derecho.

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%.