Nicolás Sobrino

Initial outcome of percutaneous balloon valvuloplasty in rheumatic tricuspid valve stenosis

Abstract Percutaneous balloon valvuloplasty (PBV) has been used as an effective treatment for some cases of valvular stenosis, mainly in the mitral, 1 pulmonary 2 and aortic 3 valves. Less experience has been achieved with this procedure for valvular tricuspid stenosis. 4–7 We present the immediate results of 5 cases of PBV in stenotic tricuspid valves.

Transient Entrainment of Bundle-Branch Reentry by Atrial and Ventricular Stimulation Elucidation of the Tachycardia Mechanism Through Analysis of the Surface ECG

BACKGROUND Different responses to entrainment have been reported in relation to the pacing site of a variety of tachycardias. However, transient entrainment of bundle-branch reentrant tachycardia (BBRT) has not been investigated systematically. METHODS AND RESULTS We attempted entrainment of 13 BBRTs in 9 patients by pacing first the right ventricle and then the right atrium. The initial pacing cycle length (CL) was 10 ms faster than the tachycardia CL. Subsequent pacing sequences were performed with 5- to 10-ms CL decrements until tachycardia termination or loss of postatropine 1:1 AV conduction. Both full ventricular-paced and AV-conducted QRS complex references were obtained during sinus rhythm pacing from the same sites and with similar CL as during entrainment. Transient entrainment was achieved by ventricular and atrial stimulation in 11 and 8 tachycardias, respectively. Constant fusion was always present during entrainment by ventricular stimulation. There was no change in the QRS complex (orthodromically concealed fusion) during entrainment by atrial stimulation in 6 of 6 tachycardias with left bundle-branch block morphology and in 1 of 2 tachycardias with right bundle-branch block morphology. CONCLUSIONS BBRT, especially if it has a left bundle-branch block morphology, can be differentiated from other wide-QRS-complex tachycardia mechanisms through analysis of the ECGs recorded during tachycardia entrainment by atrial and ventricular stimulation. This diagnostic approach may be especially useful when it is difficult to record a stable or sufficiently sized His bundle electrogram or when spontaneous changes in the ventricular CL precede similar changes in the His bundle CL.

Utilización de enoxaparina o heparina no fraccionada en combinación con abciximab durante la intervención coronaria percutánea: estudio piloto aleatorizado

Objectives. The cumulative experience gleaned from the NICE trials suggests that adjunctive enoxaparin therapy for percutaneous transluminal coronary angioplasty (PTCA), with or without concomitant abciximab therapy, is both safe and effective. However, no randomized studies have been conducted to compare the two strategies. The aim of this study was to evaluate the safety of combined enoxaparin-abciximab compared with standard therapy using unfractionated heparin and abciximab. Patients and method. Ninety-nine patients undergoing PTCA were randomly assigned to receive either enoxaparin (enoxaparin group, 50 patients, 0.75 mg/kg) or unfractionated heparin (UH group, 49 patients, 70 U/kg) in an intravenous bolus. Both groups received standard abciximab treatment. The aPTT, creatine kinase (CPK), MB, troponin I, hemoglobin, and platelet count were determined 5 h and 17 h after PTCA. Endpoints were major bleeding and clinical or biochemical in-hospital events. Results. There was less major bleeding in the enoxaparin group than in the UH group (1 vs 4) but the difference was not statistically significant. There were no significant differences in the frequency of in-hospital clinical events. There was a lower increase in aPTT at 5 h in the enoxaparin vs UH group (p = 0.02). It was impossible to remove the introducer in 7 of the UH group patients due to aPTT > 60 s as opposed to 1 patient in the enoxaparin group. Post-procedural CK elevation occurred in 8.0% of the enoxaparin group and in 6.1% of the UH group (p = NS). No thrombocytopenia was observed in either group. Conclusions. Combined enoxaparin-abciximab as an adjuvant therapy during PTCA was safe and associated with a low incidence of major bleeding, major ischemic inhospital events, and post-procedural CPK elevation.

Effectiveness of balloon percutaneous valvuloplasty for stenotic bioprosthetic valves in different positions

Abstract Percutaneous balloon valvuloplasty has been used as treatment for native valvular stenosis in the mitral, aortic, pulmonary and tricuspid positions. 1–4 It has also been used as palliative therapy for stenotic bioprosthetic valves. 5–8 In this study we present the immediate results and midterm follow up of percutaneous balloon valvuloplasty of 5 bioprosthetic valves in different positions.

Respuesta variable a la inhibición biológica de las plaquetas por abciximab en pacientes sometidos a revascularización coronaria percutánea

Introduccion y objetivo La utilizacion de abciximab ha demostrado reducir el riesgo de complicaciones tromboticas en el contexto de la angioplastia coronaria transluminal percutanea (ACTP). Sin embargo, todavia quedan aspectos por resolver. Se han estudiado varios aspectos biologicos de la accion del abciximab sobre las plaquetas en la ACTP. Metodos Se determino el grado de inhibicion plaquetaria con adenosin difosfato (ADP) a concentraciones de 5 y 20 mmol/l, el tiempo de obturacion que mide la capacidad hemostatica de las plaquetas (PFA-100) y los marcadores de activacion plaquetaria en 15 pacientes sometidos a angioplastia coronaria basalmente, a los 15 min, al finalizar la intervencion y a las 24 h de ser tratados con abciximab. Resultados Un total de 13 pacientes tuvieron mas de un 80% de inhibicion de la agregacion plaquetaria durante el procedimiento, pero solo dos la mantenian a las 24 h (p de 300 s en 13 pacientes durante el procedimiento, normalizandose a las 24 h en seis (p Conclusiones La variabilidad en la inhibicion de la funcion plaquetaria y la existencia de activacion circulante durante la intervencion hace considerar la necesidad de realizar un control analitico precoz tras la administracion de abciximab, con objeto de poder modificar su pauta para optimizar su accion o asociarlo a otro agente antitrombotico.

Bradycardia-dependent interatrial block with retrograde left atrial activation.

A patient with a peculiar interatrial block is reported. The electrocardiogram showed a short PR interval and negative P waves in II, III, and aVF, which were preceded, 0-07 s earlier, by another positive P wave present in the right praecordial leads which were absent in the limb leads. From the study with His bundle electrograms, high right atrial electrograms, and bipolar oesophageal electrocardiograms, it could be proved that atrioventricular, His-Purkinje, and right intra-atrial conduction were normal, and that P waves recorded in limb leads represented left atrial depolarization; whereas the ones in the right praecordial leads corresponded to right atrial activation. The vectorial analysis from both P waves and atrial potentials showed that the left atrium was activated in a retrograde fashion, because of an interatrial block. This block was bradycardia dependent and it disappeared in the cycles shorter than 800 ms.

Disappearance of right bundle branch block with left anterior hemiblock when associated with a type B pre-excitation syndrome

Abstract A patient with mitral valve disease showing RBBB plus LAH with an intermittent association of type B pre-excitation is presented. The bifascicular block is masked by the existence of pre-excitation. The RBBB image is entirely canceled and the LAH is altered because its inital forces are replaced by a delta wave. The electrical axis in the frontal plane is also modified. The mechanism of production of this ventricular complex is explained on the basis of the premature excitation of the right ventricle and the sum of forces produced by the activation through the posteroinferior division of the left bundle.

Budd-Chiari Syndrome With Complete Occlusion of the Inferior Vena Cava: Percutaneous Recanalization by Angioplasty and Stenting

A 47-year-old man was diagnosed with primary antiphospholipid syndrome and Budd-Chiari syndrome (membranous complete obstruction of the intrahepatic inferior vena cava), with edema and ascites refractory to medical treatment. The inferior vena cava membrane was punctured with a Brockenbrough needle under multidirectional fluoroscopic guidance via a transfemoral approach. The occlusion was dilated with balloons of increasing size and was subsequently stented successfully. At 1-year follow-up venography showed patency of the stent, and the patient remains asymptomatic 2 years after the procedure.

Left ventricular cavity obliteration: hemodynamic behavior of the postextrasystolic beat

Abstract Thirteen patients with angiographic left ventricular cavity obliteration are analyzed. No transvalvular or subvalvular gradients were present except in two cases with a mild gradient after amyl nitrite inhalation. The commonest clinical features were chest pain (60%) and dyspnea (23%). Electrocardio-graphically proved left ventricular hypertrophy (70%) was prominent. The echocardiograms showed asymmetric septal hypertrophy (40%), symmetric hypertrophy (20%), systolic anterior motion of the anterior leaflet of the mitral valve (60%), and mitral valve prolapse (20%). In all the patients changes in systolic intraventricular pressure in the post-extrasystolic beat were evaluated and a decrease in intraventricular pressure was found in every case. In the four cases with extrasystoles recorded in the aorta a similar decrease of aortic pressure was found. This behavior is completely different in the hypertrophic cardiomyopathy with obstruction to the left ventricular outflow tract, where there is an increase in intraventricular pressure and a decrease in aortic pressure in the postextrasystolic beat. Left ventricular cavity obliteration is an angiographic phenomenon which is common in hypercontractile states, being an usual finding in hypertrophic cardiomyopathy. In cases without obstruction to the left ventricular outflow tract, the decrease in aortic pressure is caused by a different mechanism than the one involved in cases with obstruction. In cases without obstruction, the decrease in post-extrasystolic aortic pressure corresponds to a decrease in intraventricular pressure, whereas in subaortic stenosis there is an increase both of intraventricular pressure and gradient with the subsequent decrease in aortic pressure.