Análisis tiempo-frecuencia de la fibrilación ventricular. Estudio experimental

Introduction and objectives. The analysis of frequency variability during ventricular fibrillation has yielded inconsistent results. We used an experimental model of ventricular fibrillation, with a short timescale, to analyze variations in frequency and their associated spatial distribution. Methods. Epicardial recordings of ventricular fibrillation were made in 10 perfused isolated rabbit heart preparations using a multiple electrode system (i.e., 240 unipolar electrodes). Both spectral and time-frequency analysis were used to derive the dominant frequency in the anterolateral wall of the left ventricle. Results. Linear regression analysis showed that there was a good correlation between …

Usefulness of Clinical Data and Biomarkers for the Identification of Frailty After Acute Coronary Syndromes

Abstract Background Frailty predicts mortality after acute coronary syndrome (ACS). The standard frailty scales, such as the Fried score, consist of a variety of questionnaires and physical tests. Our aim was to investigate easily available clinical data and blood markers to predict frailty at discharge, in elderly patients after ACS. Methods A total of 342 patients older than 65 years, survivors after ACS, were included. A high number of clinical variables were collected. In addition, blood markers potentially linked to frailty and related to the processes of inflammation, coagulation, hormonal dysregulation, nutrition, renal dysfunction, and heart dysfunction were determined. Frailty was …

Microvascular obstruction in the right ventricle in reperfused anterior myocardial infarction: macroscopic and pathologic evidence in a swine model

Modifications in Ventricular Fibrillation and Capture Capacity Induced by a Linear Radiofrequency Lesion

[EN] Introduction and objectives: An analysis was made of the effects of a radiofrequency-induced linear lesion during ventricular fibrillation and the capacity to capture myocardium through high-frequency pacing. Methods: Using multiple epicardial electrodes, ventricular fibrillation was recorded in 22 isolated perfused rabbit hearts, analyzing the activation maps upon applying trains of stimuli at 3 different frequencies close to that of the arrhythmia: a) at baseline; b) after radio-frequency ablation to induce a lesion of the left ventricular free wall (length=10 [1] mm), and c) after lengthening the lesion (length=23 [2] mm). Results: Following lesion induction, the regularity of the r…

Changes in the Spectral Characteristics of Ventricular Fibrillation in Lesions Produced by Radiofrequency Ablation. An Experimental Study

INTRODUCTION AND OBJECTIVES Although electro- physiological databases contain information about changes in the time domain in lesions produced by radiofrequency ablation, very few data on changes in the frequency domain are available. The aim of this study was to investigate changes in the spectral characteristics of ventricular fibrillation in zones with radiofrequency lesions. METHODS Recordings of ventricular fibrillation were obtained in 11 isolated perfused rabbit heart preparations using a multiple epicardial electrode located on the left ventricular free wall. Spectral parameters derived by Fourier analysis before and after the creation of transmural radiofrequency lesions were compa…

Limitations of Clinical History for Evaluation of Patients With Acute Chest Pain, Non-Diagnostic Electrocardiogram, and Normal Troponin

Decision making and risk stratification for patients with acute chest pain, nondiagnostic electrocardiogram results, and normal troponin levels are challenging. The aim of this study was to optimize the clinical history for the evaluation of these patients. A total of 1,011 patients presenting to an emergency department were included. The following data were collected: clinical presentation (pain characteristics and number of pain episodes), coronary risk factors, previous ischemic heart disease, and extracardiac vascular disease (peripheral artery disease, stroke, or creatinine >1.4 mg/dl). Two different predictive models were calculated according to the end points: model 1 for 1-year majo…

Patrones de activación durante la fibrilación auricular en un modelo experimental

Introduccion y objetivos En la fibrilacion auricular junto a los mecanismos de reentrada y de activacion aleatoria se han descrito patrones de activacion focal que se han atribuido tanto a propagacion desde el endocardio como a la existencia de zonas de actividad automatica. Los objetivos del presente estudio son analizar y cuantificar los patrones de activacion auricular en un modelo experimental de fibrilacion. Material y metodos Se estudian 11 preparaciones de corazon aislado de conejo segun la tecnica de Langendorff en los que se inducen episodios de fibrilacion auricular mediante sobreestimulacion tras haber provocado dilatacion auricular derecha con un balon intraauricular. Utilizando…

Prognostic value of the interaction between galectin-3 and antigen carbohydrate 125 in acute heart failure

AIM:Galectin-3 (Gal-3) and carbohydrate antigen 125 (CA125) have emerged as robust prognostic biomarkers in heart failure. Experimental data have also suggested a potential molecular interaction between CA125 and Gal-3; however, the biological and clinical relevance of this interaction is still uncertain. We sought to evaluate, in patients admitted for acute heart failure, the association between plasma Gal-3 with all-cause mortality and the risk for rehospitalizations among high and low levels of CA125. METHODS AND RESULTS: We included 264 consecutive patients admitted for acute heart failure to the Cardiology Department in a third-level center. Both biomarkers were measured on admission. …

Usefulness of the neutrophil to lymphocyte ratio in predicting long-term mortality in ST segment elevation myocardial infarction.

Neutrophil to lymphocyte ratio (N/L) has been associated with poor outcomes in patients who underwent cardiac angiography. Nevertheless, its role for risk stratification in acute coronary syndromes, specifically in patients with ST-segment elevation myocardial infarction (STEMI), has not been elucidated. We sought to determine the association of N/L maximum value (N/L max) with mortality in the setting of STEMI and to compare its predictive ability with total white blood cell maximum count (WBC max). We analyzed 515 consecutive patients admitted with STEMI to a single university center. White blood cells (WBC) and differential count were measured at admission and daily for the first 96 hour…

[Effect of flecainide on longitudinal and transverse conduction velocities in ventricular myocardium. An experimental study].

It is known that the effect of flecainide on longitudinal and transverse ventricular conduction velocities depends on the coupling interval. If this is so, whether the longitudinal or transverse direction is predominantly affected could depend on the magnitude of the coupling interval. In order to investigate this hypothesis, we studied the effect of flecainide, 1 micromol/L, on conduction velocities in excised heart preparations from 11 rabbits using a basal cycle length of 250 ms and inserting two extrastimuli at a decreasing coupling interval. Flecainide significantly reduced both conduction velocities. However, the effect increased as the coupling interval decreased for only the longitu…

Relationship between low lymphocyte count and major cardiac events in patients with acute chest pain, a non-diagnostic electrocardiogram and normal troponin levels.

Risk stratification of patients with acute chest pain, non-diagnostic electrocardiogram and normal troponin (ACPneg) remains a challenge, partly because no standardized set of biomarkers with prognostic ability has been identified in this population. Lymphopenia has been associated with atherosclerosis progression and adverse outcomes in cardiovascular diseases; although its prognostic value in ACPneg is unknown. We sought to determine the relationship between the lymphocyte count obtained in the Emergency Department (ED) and the risk of the long-term all-cause mortality or myocardial infarction (MI) in patients with ACPneg.We analyzed 1030 consecutive patients admitted with ACPneg in our i…

Usefulness of delta troponin for diagnosis and prognosis assessment of non-ST-segment elevation acute chest pain.

The additional diagnostic and prognostic information provided by delta high-sensitivity troponin T (hs-cTnT) in patients with acute chest pain and hs-cTnT elevation remains unclear.The study group consisted of 601 patients presenting at the emergency department with non-ST-segment elevation acute chest pain and hs-cTnT elevation after two determinations (admission and within the first six hours). Maximum hs-cTnT and delta hs-cTnT (absolute or percentage change between the two measurements) were considered. Cutoff values were optimized using the quartile distribution for the endpoints. The endpoints were diagnostic (significant stenosis in the coronary angiogram) and prognostic (death or rec…

The Sum of ST-Segment Elevation Is the Best Predictor of Microvascular Obstruction in Patients Treated Successfully by Primary Percutaneous Coronary Intervention. Cardiovascular Magnetic Resonance Study

Introduction and objectives The usefulness of ST-segment elevation resolution (STR) for predicting epicardial reperfusion is well established. However, it is still not clear how ST-segment changes are related to microvascular obstruction (MVO) observed by cardiovascular magnetic resonance (CMR) after primary percutaneous coronary intervention (pPCI) for ST-segment elevation myocardial infarction (STEMI). Methods The study involved 85 consecutive patients admitted for a first STEMI and treated by pPCI who had a patent infarct-related artery. An ECG was recorded on admission and 90 min and 6, 24, 48 and 96 h after pPCI. Thereafter, STR and the sum of ST-segment elevation (sumSTE) in all leads…

Antigen carbohydrate 125 and brain natriuretic peptide serial measurements for risk stratification following an episode of acute heart failure.

Abstract Background The prognostic utility of combining serial measurements of brain natriuretic peptide (BNP) and antigen carbohydrate 125 (CA125) is largely unknown. The aim of this work is to assess the prognostic utility of serial measurements of BNP, CA125, and their optimal combination for predicting long-term mortality, following a hospitalization for acute heart failure (AHF). Methods and results We analyzed 293 consecutive patients admitted with AHF where CA125 and BNP were measured at discharge (T1) and at the first ambulatory visit (T2: median 31days after discharge). Biomarkers were evaluated as snapshot determinations or as serial changes in absolute, relative or categorical ch…

Contractile Reserve and Extent of Transmural Necrosis in the Setting of Myocardial Stunning: Comparison at Cardiac MR Imaging

To perform a comparison of cardiac magnetic resonance (MR) imaging-derived ejection fraction (EF) during low-dose dobutamine infusion (EF(D)) with the extent of segments with transmural necrosis in more than 50% of their wall thickness (ETN) for the prediction of major adverse cardiac events (MACEs) and late systolic recovery soon after a first ST-segment elevation myocardial infarction (STEMI).Institutional ethics committee approval and written informed consent were obtained. One hundred nineteen consecutive patients with a first STEMI, a depressed left ventricular EF, and an open infarct-related artery underwent MR imaging at 1 week after infarction. EF(D) and ETN (by using a 17-segment m…

The DD genotype of the angiotensin converting enzyme gene independently associates with CMR-derived abnormal microvascular perfusion in patients with a first anterior ST-segment elevation myocardial infarction treated with thrombolytic agents

Abstract Introduction The role of the angiotensin converting enzyme (ACE) gene on the result of thrombolysis at the microvascular level has not been addressed so far. We analyzed the implications of the insertion/deletion (I/D) polymorphism of the ACE gene on the presence of abnormal cardiovascular magnetic resonance (CMR)-derived microvascular perfusion after ST-segment elevation myocardial infarction (STEMI). Materials and Methods We studied 105 patients with a first anterior STEMI treated with thrombolytic agents and an open left anterior descending artery. Microvascular perfusion was assessed using first-pass perfusion CMR at 7 ±1 days. CMR studies were repeated 184 ± 11 days after STEM…

Low lymphocyte count in acute phase of ST-segment elevation myocardial infarction predicts long-term recurrent myocardial infarction

Objective We sought to determine the relationship between the lowest lymphocyte count (lymphocyte(min))obtained within the first 96 h of symptoms onset and the risk of postdischarge recurrent spontaneous myocardial infarction (re-MI) in patients admitted with ST-segment elevation MI (STEMI). Methods We analyzed 549 consecutive patients admitted with STEMI from a single academic hospital. Lymphocyte counts were determined at admission and routinely during the first 96 h. Lymphocyte(min) was selected as the main exposure. Patients with inflammatory or infectious diseases, in-hospital death, or reinfarction were excluded from the analysis (final sample= 426 patients). Lymphocyte(min) was divid…

Release of necrosis markers and cardiovascular magnetic resonance-derived microvascular perfusion in reperfused ST-elevation myocardial infarction

Abstract Introduction The association of the temporal evolution of cardiac necrosis marker release with cardiovascular magnetic resonance-derived microvascular perfusion after ST-elevation myocardial infarction is unknown. Methods We analyzed 163 patients with a first ST-elevation myocardial infarction and a patent infarct-related artery treated with thrombolysis (67%) or primary angioplasty (33%). Using first-pass perfusion CMR, abnormal perfusion was defined as a lack of contrast arrival into the infarct area in > 1 segment. Troponin I, creatine kinase MB and myoglobin were measured upon arrival and at 6, 12, 24, 48 and 96 hours after reperfusion. Results Abnormal perfusion was detected i…

Naked DNA delivery to whole pig cardiac tissue by coronary sinus retrograde injection employing non-invasive catheterization.

Background Hydrodynamic injection has demonstrated to be very efficient in the liver of small animals, although this procedure must be translated to the clinical practice in a milder but no less efficient way. The present study evaluates the capacity of non-invasive interventional catheterization as a procedure for naked DNA delivery to the heart in large animals. Methods Two catheters were placed in the coronary sinus: one of them to block blood circulation and the other to retrogradely inject 50 ml of a saline solution of DNA (20 µg/ml) containing the enhanced green fluorescent protein (EGFP) gene, at a flow rate of 5 ml/s. Results The results obtained show that EGFP protein, identified b…

Prognostic value of dipyridamole stress cardiovascular magnetic resonance imaging in patients with known or suspected coronary artery disease.

ObjectivesWe evaluated the prognostic value of dipyridamole stress cardiovascular magnetic resonance imaging (CMR) in patients with chest pain and known or suspected coronary artery disease.BackgroundStress perfusion CMR has been incorporated in daily practice. Data on its prognostic value are preliminary.MethodsDipyridamole stress CMR was performed in 420 patients with chest pain and known or suspected coronary artery disease. The extent (number of segments according to the 17-segment model) of abnormal wall motion at rest (AWM-rest), abnormal wall motion with dipyridamole (AWM-D), perfusion deficit (at stress first-pass perfusion imaging), and delayed enhancement (at late enhancement imag…

Effect of ischemic postconditioning on microvascular obstruction in reperfused myocardial infarction. Results of a randomized study in patients and of an experimental model in swine.

Background: Ischemic postconditioning (PCON) appears as a potentially beneficial tool in ST-segment elevation myocardial infarction (STEMI). We evaluated the effect of PCON on microvascular obstruction (MVO) in STEMI patients and in an experimental swine model. Methods: A prospective randomized study in patients and an experimental study in swine were carried out in two university hospitals in Spain. 101 consecutive STEMI patients were randomized to undergo primary angio-plasty followed by PCON or primary angioplasty alone (non-PCON). Using late gadolinium enhancement cardiovascular magnetic resonance, infarct size and MVO were quantified (% of left ventricular mass). In swine, using an ang…

Analyzing the electrophysiological effects of local epicardial temperature in experimental studies with isolated hearts

As a result of their modulating effects upon myocardial electrophysiology, both hypo- and hyperthermia can be used to study the mechanisms that generate or sustain cardiac arrhythmias. The present study describes an original electrode developed with thick-film technology and capable of controlling regional temperature variations in the epicardium while simultaneously registering its electrical activity. In this way, it is possible to measure electrophysiological parameters of the heart at different temperatures. The results obtained with this device in a study with isolated and perfused rabbit hearts are reported. An exploration has been made of the effects of local temperature changes upon…

Additional diagnostic value of systolic dysfunction induced by dipyridamole stress cardiac magnetic resonance used in detecting coronary artery disease.

Dipyridamole stress perfusion cardiovascular magnetic resonance (CMR) is used to detect coronary artery disease (CAD). However, few data are available on the diagnostic value of the systolic dysfunction induced by dipyridamole. This study investigated whether the induction of systolic dysfunction supplements the diagnostic information provided by perfusion imaging in the detection of CAD.Overall, 166 patients underwent dipyridamole CMR and quantitative coronary angiography, with CAD being defined as a stenosisor =70%. Systolic dysfunction at rest, systolic dysfunction with dipyridamole, induced systolic dysfunction, and stress first-pass perfussion deficit (PD) and delayed enhancement were …

Influencia del tipo de registro (unipolar o bipolar) en las características espectrales de los registros epicárdicos de la fibrilación ventricular. Estudio experimental

Introduction and objectives. The aim of this study was to examine the hypothesis that the recording mode (ie, unipolar or bipolar) affects the information obtained using spectral analysis techniques during ventricular fibrillation by carrying out an experiment using epicardial electrodes. Methods. Recordings of ventricular fibrillation were obtained in 29 isolated rabbit hearts using a multipleelectrode probe located on the left ventricular free wall. The parameter values obtained in the frequency domain (by Fourier analysis) using unipolar or bipolar electrodes, different interelectrode distances, and different orientations (ie, horizontal, vertical, or diagonal) were compared. Results. Ch…

Hyperuricemia in acute heart failure. More than a simple spectator?

Hyperuricemia is a prevalent condition in chronic heart failure (CHF), describing increased oxidative stress and inflammation. Although there is evidence that serum uric acid (UA) predicts mortality in CHF, its role as a prognostic biomarker in acute heart failure (AHF) has not yet been well assessed. The aim of this study was to determine if UA levels predict all-cause mortality. Additionally, as a secondary endpoint we sought the clinical predictors of UA serum level in this population.We analyzed 560 consecutive patients with AHF admitted in a single university center. UA (mg/dl) was measured during early hospitalization. Patient survival status was followed up after discharge (median fo…

Modificaciones de las características espectrales de la fibrilación ventricular en las lesiones producidas con radiofrecuencia. Estudio experimental

Introduccion y objetivos Aunque se dispone de informacion sobre las modificaciones en el dominio del tiempo de los registros electrofisiologicos en zonas lesionadas con radiofrecuencia, los datos disponibles en el dominio de la frecuencia son muy escasos. Se analizan las modificaciones de las caracteristicas espectrales de la fibrilacion ventricular en zonas lesionadas con radiofrecuencia. Metodos En 11 preparaciones de corazon aislado y perfundido de conejo, se registra la fibrilacion ventricular con un electrodo multiple epicardico situado en la pared libre ventricular izquierda. Se comparan los parametros espectrales obtenidos mediante analisis de Fourier antes y despues de practicar les…

Frailty and other geriatric conditions for risk stratification of older patients with acute coronary syndrome

Background Geriatric conditions may predict outcomes beyond age and standard risk factors. Our aim was to investigate a wide spectrum of geriatric conditions in survivors after an acute coronary syndrome. Methods A total of 342 patients older than 65 years were included. At hospital discharge, 5 geriatric conditions were evaluated: frailty (Fried and Green scores), physical disability (Barthel index), instrumental disability (Lawton-Brody scale), cognitive impairment (Pfeiffer questionnaire), and comorbidity (Charlson and simple comorbidity indexes). The outcomes were postdischarge mortality and the composite of death/myocardial infarction during a 30-month median follow-up. Results Seventy…

Alteration of Ventricular Fibrillation by Flecainide, Verapamil, and Sotalol

Background—The purpose of this study was to determine whether the myocardial electrophysiological properties are useful for predicting changes in the ventricular fibrillatory pattern. Methods and Results—Thirty-two Langendorff-perfused rabbit hearts were used to record ventricular fibrillatory activity with an epicardial multiple electrode. Under control conditions and after flecainide, verapamil, or d,l-sotalol, the dominant frequency (FrD), type of activation maps, conduction velocity, functional refractory period, and wavelength (WL) of excitation were determined during ventricular fibrillation (VF). Flecainide (1.9±0.3 versus 2.4±0.6 cm, P<0.05) and sotalol (2.1±0.3 versus 2.5±0.5 cm, P…

Cartografía epicárdica de la activación reentrante durante la fibrilación ventricular. Estudio experimental

Introduccion y objetivos Analizar las caracteristicas de la activacion reentrante durante la fibrilacion ventricular en un modelo experimental mediante cartografia epicardica de alta resolucion. Metodos En 30 preparaciones de corazon aislado de conejo se ha registrado la actividad fibrilatoria ventricular utilizando un electrodo multiple epicardico. En los mapas de activacion con patrones de activacion reentrante se han determinado el numero de giros consecutivos, la longitud maxima de la zona central de la reentrada, el area abarcada por la zona central y dos electrodos alrededor de la misma y la duracion de los ciclos. Resultados En la mayor parte de los mapas se han observado patrones co…

Modificaciones de la fibrilación ventricular y de la capacidad de captura inducidas por una lesión lineal con radiofrecuencia

Resumen Introduccion y objetivos Analizar los efectos, en la fibrilacion ventricular y en la capacidad de capturar al miocardio mediante estimulacion a frecuencias rapidas, de una lesion lineal producida con radiofrecuencia. Metodos En 22 corazones de conejo aislados y perfundidos, se utilizaron electrodos multiples epicardicos para registrar la fibrilacion ventricular. Se analizaron los mapas de activacion al aplicar trenes de estimulos a tres frecuencias distintas, cercanas a las de la arritmia, en tres situaciones: a) basalmente; b) tras producir con radiofrecuencia una lesion en la pared libre del ventriculo izquierdo (longitud, 10 ± 1 mm), y c) tras ampliar su extension (longitud, 23 ±…

La suma de la elevación del segmento ST predice mejor la obstrucción microvascular en pacientes tratados con éxito con una intervención coronaria percutánea primaria. Un estudio de resonancia magnética cardiovascular

Introduccion y objetivos La utilidad de la resolucion del segmento ST (RST) para la prediccion de la reperfusion epicardica esta bien establecida. La asociacion de los cambios del segmento ST con la obstruccion microvascular (OMV) observada en la resonancia magnetica cardiovascular (RMC) tras una intervencion coronaria percutanea primaria (ICPp) en el infarto de miocardio con elevacion del ST (IMEST) no se ha aclarado todavia. Metodos Estudiamos a 85 pacientes consecutivos ingresados por un primer IMEST y tratados con una ICPp que tenian una arteria relacionada con el infarto permeable. Se registro un ECG al ingreso, tras 90 min y tras 6, 24, 48 y 96 h de la ICPp. Se calculo la RST y la sum…

A suspicious calcium spike.

Right ventricular involvement in anterior myocardial infarction: a translational approach.

Aims The aim of the present study was to evaluate the involvement of the right ventricle (RV) in reperfused anterior ST-elevation myocardial infarction (STEMI). Methods and results Left anterior descending (LAD)-perfused area (using thioflavin-S staining after selective infusion in proximal LAD artery, %), infarct size (using triphenyltetrazolium chloride staining, %), and salvaged myocardium (% of LAD-perfused area) in the right and left ventricle (LV) were quantified in a 90-min LAD occlusion 3-day reperfusion model in swine ( n = 8). Additionally, we studied, using cardiovascular magnetic resonance, 20 patients with a first STEMI due to proximal LAD occlusion treated with primary angiopl…

Insuficiencia cardiaca aguda post-alta hospitalaria tras un síndrome coronario agudo sin elevación del segmento-ST y riesgo de muerte e infarto agudo de miocardio subsiguiente

Introduccion y objetivos. La informacion disponible acerca del impacto pronostico de un episodio de rehospitalizacion por insuficiencia cardiaca aguda (ICA) tras un sindrome coronario agudo sin elevacion del segmento ST (SCASEST) es escasa. El objetivo de este trabajo fue evaluar el valor pronostico atribuible a un primer ingreso por ICA en cuanto a riesgo de infarto agudo de miocardio (IAM) y mortalidad en pacientes supervivientes a un episodio de SCASEST de alto riesgo. Metodos. Analizamos consecutivamente a 972 pacientes supervivientes a la fase hospitalaria de un SCASEST de alto riesgo. El reingreso por ICA se considero como la variable principal de estudio, y su asociacion con IAM y mo…

Efficacy of coronary revascularization in patients with acute chest pain managed in a chest pain unit.

To investigate the safety of discharge of patients deemed at low risk of cardiac events after evaluation in a chest pain unit and to determine the prognostic effect of revascularization of patients deemed at high risk.The study population consisted of 1088 patients presenting at the emergency department from January 15, 2001, to September 1, 2006, with chest pain but without ischemia on electrocardiography or troponin elevation. Patients were managed by a chest pain unit protocol that included early exercise testing. Three groups of patients were distinguished: (1) those discharged after exercise testing (424 [39%]); (2) those in whom unstable angina was ruled out after in-hospital evaluati…

Vasodilator Stress CMR and All-Cause Mortality in Stable Ischemic Heart Disease

Abstract Objectives This study explored the association of ischemic burden, as measured by vasodilator stress cardiovascular magnetic resonance (CMR), with all-cause mortality and the effect of revascularization on all-cause mortality in patients with stable ischemic heart disease (SIHD). Background In patients with SIHD, the association of ischemic burden, derived from vasodilator stress CMR, with all-cause mortality and its role for decision-making is unclear. Methods The registry consisted of 6,389 consecutive patients (mean age: 65 ± 12 years; 38% women) who underwent vasodilator stress CMR for known or suspected SIHD. The ischemic burden (at stress first-pass perfusion imaging) was com…

Valor diagnóstico adicional de la disfunción sistólica inducida para la detección de enfermedad coronaria mediante resonancia magnética cardiaca de estrés con dipiridamol

Introduccion y objetivos La perfusion con dipiridamol en resonancia magnetica cardiaca (RMC) de estres se utiliza para la deteccion de enfermedad de las arterias coronarias (EAC). Sin embargo, se carece de informacion sobre el valor diagnostico de la disfuncion sistolica (DS) inducida con dipiridamol. Este estudio se centra en investigar si la DS inducida aporta un valor diagnostico adicional junto con la perfusion para la deteccion de las EAC. Metodos Se sometio a 166 pacientes a una RMC con dipiridamol y a una angiografia coronaria cuantitativa. Se definio EAC para valores ≥ 70% de estenosis. Se analizo la extension de la DS en reposo, la DS con dipiridamol, la DS inducida, el deficit de …

Efecto del estiramiento miocárdico sobre las frecuencias de activación determinadas mediante análisis espectral durante la fibrilación ventricular

Introduction and objectives. The aim of this study was to analyze the effects of myocardial stretching on excitation frequencies, as determined by spectral analysis, during ventricular fibrillation. Methods. In 12 isolated rabbit heart preparations, ventricular activation during ventricular fibrillation was recorded with multiple electrodes. Recordings were obtained before, during and after ventricular dilatation produced with an intraventricular balloon. The dominant frequency of the signals obtained with each of the electrodes was determined by spectral analysis. Results. During the control phase, the mean, minimum and maximum dominant frequencies were, respectively, 14.3 ± 1.7, 12.5 ± 1.…

Randomized comparison between clinical evaluation plus N-terminal pro–B-type natriuretic peptide versus exercise testing for decision making in acute chest pain of uncertain origin

Background Exercise testing constitutes the usual tool for decision making in chest pain units. This policy implies logistical constrains. Our aim was to evaluate a new strategy, combining a clinical risk score and N-terminal pro–B-type natriuretic peptide (NT-proBNP), in patients presenting to the emergency department with chest pain, without ischemic electrocardiogram changes or troponin elevation. Methods A total of 320 patients were randomized to either usual management, involving exercise testing, or a new strategy combining a clinical risk score and NT-proBNP without exercise testing. In the usual management, discharge decision was guided by the result of exercise test. In the new str…

Metabolomic Profile of Human Myocardial Ischemia by Nuclear Magnetic Resonance Spectroscopy of Peripheral Blood Serum

Objectives The aim of this study was to investigate the metabolomic profile of acute myocardial ischemia (MIS) using nuclear magnetic resonance spectroscopy of peripheral blood serum of swine and patients undergoing angioplasty balloon‐induced transient coronary occlusion. Background Biochemical detection of MIS is a major challenge. The validation of novel biosignatures is of utmost importance. Methods High-resolution nuclear magnetic resonance spectroscopy was used to profile 32 blood serum metabolites obtained (before and after controlled ischemia) from swine (n 9) and patients (n 20) undergoing transitory MIS in the setting of planned coronary angioplasty. Additionally, blood serum of c…

Valor pronóstico de la fracción de eyección del ventrículo izquierdo en pacientes con insuficiencia cardíaca aguda

Fundamento y objetivo La influencia de la fraccion de eyeccion del ventriculo izquierdo (FEVI) en el pronostico de los pacientes con insuficiencia cardiaca es motivo de controversia. El objetivo de nuestro estudio ha sido determinar, durante un seguimiento a largo plazo, el valor pronostico de la FEVI sobre la mortalidad y el reingreso hospitalario por insuficiencia cardiaca aguda (ICA) en una poblacion no seleccionada de pacientes ingresados por ICA. Pacientes y metodo Estudiamos a 507 pacientes consecutivos ingresados por ICA en el Servicio de Cardiologia de nuestro centro. Se determino la FEVI mediante ecocardiografia transtoracica durante el ingreso indice, y durante el seguimiento se r…

Prognostic Value of a Comprehensive Cardiac Magnetic Resonance Assessment Soon After a First ST-Segment Elevation Myocardial Infarction

ObjectivesTo evaluate the prognostic value of a comprehensive cardiac magnetic resonance (CMR) assessment soon after a first ST-segment elevation myocardial infarction (STEMI).BackgroundCMR allows for a simultaneous assessment of wall motion abnormalities (WMA), WMA with low-dose dobutamine (WMA-dobutamine), microvascular obstruction, and transmural necrosis. This approach has been proven to be useful to predict late systolic recovery soon after STEMI. Its prognostic value and the relative prognostic weight of these indexes are not well-defined.MethodsWe studied 214 consecutive patients with a first STEMI treated with thrombolytic therapy or primary angioplasty discharged from hospital. In …

Perfusión miocárdica alterada tras un infarto en pacientes con flujo TIMI 3 mantenido. ¿Sólo un fenómeno agudo?

Introduccion y objetivos Se ha senalado que la perfusion anormal analizada mediante resonancia magnetica cardiaca (RMC) es una alteracion transitoria de la microcirculacion despues de un infarto agudo de miocardio (IAM) con flujo TIMI 3. Planteamos la hipotesis de que las alteraciones de la perfusion miocardica pueden persistir en los meses siguientes. Metodos Estudiamos 47 pacientes con un primer IAM y flujo TIMI 3 mantenido mediante ecografia miocardica con inyeccion intracoronaria de contraste (EMC) en la primera semana y el sexto mes postinfarto. Se considero que habia perfusion anormal mediante EMC si habia mas de un segmento hipoperfundido. Resultados En la primera semana 20 pacientes…

Modificaciones agudas de la longitud de onda del proceso de activación auricular inducidas por la dilatación. Estudio experimental

Objetivos Estudiar en un modelo experimental las modificaciones agudas de la longitud de onda del proceso de activacion auricular inducidas por la dilatacion auricular. Material y metodos En 10 preparaciones de corazon aislado y perfundido de conejo segun la tecnica de Langendorff, mediante mapeo epicardico con un electrodo multiple se determina en la auricula derecha la longitud de onda del proceso de activacion auricular (periodo refractario funcional × velocidad de conduccion) y se analiza la inducibilidad de respuestas repetitivas auriculares rapidas, cuantificando su numero tras 20 episodios de sobreestimulacion auricular rapida. Las determinaciones se efectuan en situacion basal, tras…

Efectos de la flecainida sobre las velocidades de conducción longitudinal y transversal en el miocardio ventricular. Estudio experimental

Es conocido que el efecto de la flecainida sobre las velocidades de conduccion ventricular longitudinal y transversal depende del acoplamiento entre estimulos. Si esto es asi, el predominio de los efectos en sentido longitudinal frente al transversal puede variar en funcion de dicho acoplamiento. Con el objetivo de analizar dicha hipotesis, se ha estudiado el efecto de la flecainida (1 μmol/l) sobre dichas velocidades de conduccion en 11 preparaciones de corazon aislado de conejo, para lo que se ha utilizado un tren base de estimulacion de 250 ms y se han acoplado 2 extraestimulos con acoplamiento decreciente. La flecainida ha reducido ambas velocidades de forma significativa. Este efecto s…

Pronóstico a corto plazo de los pacientes ingresados por probable síndrome coronario agudo sin elevación del segmento ST. Papel de los nuevos marcadores de daño miocárdico y de los reactantes de fase aguda

Objectives. The relative value of classic markers, myocardial damage variables, and levels of acute-phase reactants in establishing the pre-discharge prognosis of acute coronary syndrome without ST-segment elevation was analyzed. Method. We prospectively studied 385 consecutive patients admitted from our chest pain unit with a highprobability diagnosis of acute coronary syndrome without ST-segment elevation. The clinical and electrocardiographic data, myocardial damage markers (troponin I, CK-Mb mass, myoglobin), and acute-phase reactants (high-sensitivity C-reactive protein, fibrinogen) were recorded. Results. During admission, 15 deaths (3.9%) and 16 complicative infarctions (4.2%) occurr…

Características de los electrogramas auriculares registrados en las líneas de bloqueo producidas con radiofrecuencia en un modelo experimental

Objetivos Analizar y cuantificar las modificaciones de los electrogramas auriculares tras la realizacion de lesiones lineales en la pared auricular utilizando procedimientos de ablacion con radiofrecuencia. Metodos En 12 preparaciones de corazon aislado de conejo segun la tecnica de Langendorff se ha utilizado un electrodo multiple epicardico (221 electrodos unipolares) para analizar la activacion auricular antes y despues de la realizacion de una lesion lineal en la pared auricular izquierda mediante aplicaciones sucesivas de radiofrecuencia. Tras comprobar la existencia de bloqueo de la conduccion en la zona lesionada mediante cartografia epicardica y analisis de los vectores de propagaci…

Uncontrolled immune response in acute myocardial infarction

Recently, the theory that hyperinflammation is the body's primary response to potent stimulus has been challenged. Indeed, a deregulation of the immune system could be the cause of multiple organ failure. So far, clinicians have focused on the last steps of the inflammatory cascade. However, little attention has been paid to lymphocytes, which play an important role as strategists of the inflammatory response. Experimental evidence suggests a crucial role of T lymphocytes in the pathophysiology of atherosclerosis and acute myocardial infarction (AMI). In summary, from the bottom of an imaginary inverted pyramid, a few regulatory T-cells control the upper parts represented by the wide spectr…

Evolution of 5 cardiovascular magnetic resonance–derived viability indexes after reperfused myocardial infarction

The objective of this study was to evaluate the simultaneous evolution of 5 cardiovascular magnetic resonance-derived myocardial viability indexes.We studied 72 patients with a first ST-elevation myocardial infarction and sustained TIMI 3 flow. In the first week and in the sixth month of the study, using cardiovascular magnetic resonance imaging, we determined wall thickening (WT) and the following viability indexes: wall thickness, WT with low-dose dobutamine, microvascular perfusion in first-pass imaging, microvascular obstruction in late-enhancement imaging, and transmural extent of necrosis.In 250 dysfunctional segments, the evolution outcomes for the viability indexes were as follows: …

Abnormal Myocardial Perfusion After Infarction in Patients With Persistent TIMI Grade-3 Flow. Only an Acute Phenomenon?

Introduction and objectives It has been suggested that abnormal perfusion as derived from cardiovascular magnetic resonance imaging (CMR) is a transient dysfunction of microcirculation after myocardial infarction (MI) with TIMI 3 flow. We hypothesized that defects of myocardial perfusion may persist during the following months. Methods Forty-seven patients with MI and sustained TIMI 3 flow underwent intracoronary myocardial contrast echocardiography (MCE) 1 week and 6 months after infarction. Abnormal perfusion by MCE was regarded as >1 hypoperfused segment. Results At one week, 20 patients showed abnormal perfusion as derived from MCE. At six months 10 patients displayed chronic abnormal p…

Microvascular obstruction in the right ventricle in reperfused anterior myocardial infarction. Macroscopic and pathologic evidence in a swine model.

article i nfo Introduction: Data on right ventricular (RV) involvement in anterior myocardial infarction are scarce. The presence of RV microvascular obstruction (MVO) in this context has not been analyzed yet. The aim of the present study was to characterize the presence of MVO in the RV in a controlled experimental swine model of reperfused anterior myocardial infarction. Materials and Methods: Left anterior descending (LAD) artery-perfused area (thioflavin-S staining after selective infusioninLADartery),infarctsize(lackof triphenyltetrazolium-chloride staining) andMVO (lack of thioflavin-S staininginthe core oftheinfarctedarea) inthe RVwere studied.A quantitative(%of theventricularvolume…

Prognostic and therapeutic implications of dipyridamole stress cardiovascular magnetic resonance on the basis of the ischaemic cascade

To determine the prognostic and therapeutic implications of stress perfusion cardiovascular magnetic resonance (CMR) on the basis of the ischaemic cascade.Single centre study in a teaching hospital in Spain.Dipyridamole stress CMR was performed on 601 patients with ischaemic chest pain and known or suspected coronary artery disease. On the basis of the ischaemic cascade, patients were categorised in C1 (no evidence of ischaemia, n = 354), C2 (isolated perfusion deficit at stress first-pass perfusion imaging, n = 181) and C3 (simultaneous perfusion deficit and inducible wall motion abnormalities, n = 66). CMR-related revascularisation (n = 102, 17%) was defined as the procedure prompted by t…

Linfopenia post-reperfusión y obstrucción microvascular en el infarto agudo de miocardio con elevación del segmento ST

Introduccion y objetivos La obstruccion microvascular tras un infarto agudo de miocardio con elevacion del segmento ST se asocia a mal pronostico. La fisiopatologia de este fenomeno no esta totalmente definida. Analizamos las implicaciones de la linfopenia post-reperfusion en la existencia de obstruccion microvascular. Metodos Estudiamos prospectivamente a 212 pacientes que habian sufrido un primer infarto agudo de miocardio con elevacion del segmento ST reperfundido con agentes tromboliticos o con angioplastia primaria y con la arteria responsable abierta. Cuantificamos de manera seriada las cifras de linfocitos, neutrofilos y monocitos. Usamos la resonancia magnetica cardiaca para determi…

Post-Reperfusion Lymphopenia and Microvascular Obstruction in ST-Segment Elevation Acute Myocardial Infarction

The presence of microvascular obstruction after ST-segment elevation acute myocardial infarction is associated with a poor outcome. The pathophysiology of this process has not been fully defined. The aim of this study was to investigate the relationship between post-reperfusion lymphopenia and microvascular obstruction.This prospective study involved 212 patients with a first ST-segment elevation acute myocardial infarction who underwent reperfusion with thrombolytic agents or primary angioplasty and who had an open infarct-related artery. Serial measurements of lymphocyte, neutrophil and monocyte counts were taken. Cardiac magnetic resonance was used to detect microvascular obstruction dur…

Effect of acute heart failure following discharge in patients with non-ST-elevation acute coronary syndrome on the subsequent risk of death or acute myocardial infarction.

Little is known about how prognosis is influenced by readmission for acute heart failure (AHF) following non-ST-segment elevation acute coronary syndrome (NSTEACS). The aim of this study was to determine the prognostic effect of a first admission for AHF on the risk of acute myocardial infarction (AMI) or death in patients who survived an episode of high-risk NSTEACS.The study involved 972 consecutive patients with high-risk NSTEACS who survived after hospital admission. Readmission for AHF was selected as the main exposure variable, and its association with subsequent AMI or all-cause death was assessed using Cox proportional hazards models for time-dependent covariates that also included …

Dofetilide effects on the inhibition by trains of subthreshold conditioning stimuli.

We investigated the electrophysiological actions of dofetilide upon the ventricular myocardium to determine whether the drug modifies the inhibitory effects of subthreshold stimuli trains upon ventricular refractoriness. In nine Langendorff perfused rabbit hearts, ventricular epicardial electrodes were used to determine the following parameters at baseline and during dofetilide perfusion (0.5 micromolar): effective (ERP) and functional (FRP) refractory periods, conduction velocity (CV), wavelength (WL), and ERP prolongation (inhibitory effect) induced by subthreshold stimuli trains (STr) at pulse frequencies of 100, 300, and 600 Hz. Dofetilide significantly prolongs ventricular refractorine…

Effectiveness of the Relative Lymphocyte Count to Predict One-Year Mortality in Patients With Acute Heart Failure

Several works have endorsed a significant role of the immune system and inflammation in the pathogenesis of heart failure. As indirect evidence, an association between a low relative lymphocyte count (RLC%) and worse outcomes found in this population has been suggested. Nevertheless, the role of RLC% for risk stratification in a large and nonselected population of patients with acute heart failure (AHF) has not yet been determined. Thus, the aim of this study was to determine the association between low RLC% and 1-year mortality in patients with AHF and consequently to define whether it has any role for early risk stratification. A total of 1,192 consecutive patients admitted for AHF were a…