Nicasio Pérez Castellano

Usefulness of Unipolar Electrograms to Detect Isthmus Block After Radiofrequency Ablation of Typical Atrial Flutter

Background—RS morphology of the unipolar electrogram is associated with propagation of the wave front through the exploring electrode, whereas positive uniphasic (R) unipolar electrograms are characteristic of the end of activation. Methods and Results—Unipolar electrograms were recorded in 45 consecutive patients with atrial flutter who were undergoing radiofrequency ablation (RFA). Bidirectional cavotricuspid isthmus (CTI) block was achieved in 44 patients. The unipolar electrogram obtained before RFA at the low anterolateral right atrium during coronary sinus pacing changed from RS, rS, or QS to R or Rs in all patients after clockwise CTI block was obtained. The morphology of unipolar electrograms recorded close to the coronary sinus during pacing from the low anterolateral right atrium changed from RS or rS to R or Rs in all but 4 patients after counterclockwise CTI block. In the patient in whom CTI block was not achieved, the RS morphology of the unipolar electrogram remained unchanged. In 18 patients, the results of the RFA were assessed with only the unipolar electrogram. The unipolar electrogram correctly predicted 100% and 89% of the cases of clockwise and counterclockwise CTI block, respectively. Conclusions—The creation of CTI block is associated with an easily detectable loss of negative components and development of an R or Rs pattern of the unipolar electrogram recorded close to the ablation line while pacing at the opposite side of the CTI.

Estratificación del riesgo y prevención de la muerte súbita en pacientes con insuficiencia cardíaca

Los pacientes con insuficiencia cardiaca (IC) pueden fallecer como consecuencia de un fallo progresivo de bomba o de muerte subita (MS). En este articulo analizaremos los predictores de MS en pacientes con IC secundaria a disfuncion sistolica ventricular izquierda. Aunque en los estudios realizados en estos pacientes se han detectado distintos predictores univariados independientes relacionados con la supervivencia, la mayor parte de ellos ha demostrado tener un valor predictivo positivo muy limitado. El desfibrilador implantable ha confirmado ser el tratamiento mas eficaz en pacientes resucitados de una parada cardiaca debida a fibrilacion ventricular o a una taquicardia ventricular hemodinamicamente mal tolerada. La presencia de una fraccion de eyeccion ventricular izquierda baja, un mal grado funcional, una taquicardia ventricular no sostenida y la inducibilidad de arritmias ventriculares en el estudio electrofisiologico ayudan a identificar a los pacientes candidatos al implante de un desfibrilador. El papel de la amiodarona a la hora de prevenir la MS en pacientes de riesgo elevado con fracaso cardiaco parece pequeno. Se necesitan mas estudios que nos ayuden a conseguir una mejor estratificacion del riesgo en pacientes con IC, con el fin de reconocer mejor a los candidatos a un desfibrilador implantable. Palabras clave: Insuficiencia cardiaca. Muerte subita. Estratificacion del riesgo.

Percutaneous Epicardial Radiofrequency Ablation of Idiopathic Ventricular Tachycardia

We describe 3 patients with ventricular tachycardia in whom epicardial ablation was done after prior attempts of endocardial ablation had failed. Clinical ventricular tachycardia originated at the right ventricular outflow tract in one patient and near the mitral annulus in another patient. In these two cases ventricular tachycardia was mapped and successfully ablated with a percutaneous subxiphoid approach to the pericardial space. In the remaining patient, ventricular tachycardia originated near the mitral annulus and was ablated via a coronary vein. The two patients who presented tachycardiomyopathy recovered normal left ventricular function after successful ablation. Failure of endocardial ablation may reflect a substrate of epicardial arrhythmia. Epicardial ablation is effective and provides an alternative therapy for patients with ventricular tachycardia, including those with no structural heart disease.

Comments on the 2016 ESC Guidelines for the Management of Atrial Fibrillation.

In line with the methodology recommended by the Guidelines Committee of the Spanish Society of Cardiology,1 the present article discusses the innovations and most controversial aspects of the recent guidelines for atrial fibrillation (AF).2 Notably, of 154 recommendations, only 23 (15%) have a level of evidence A and 80 (52%) a level of evidence B, confirming the need for further clinical research into this condition. Some of the most novel or relevant aspects of the guidelines are summarized in Table, in conjunction with some critical comments.

Ablación epicárdica percutánea mediante radiofrecuencia de taquicardias ventriculares idiopáticas

Presentamos los casos de 3 pacientes con taquicardia ventricular en los que se realizo ablacion epicardica despues de intentos fallidos de ablacion endocardica. La taquicardia ventricular clinica se originaba en el tracto de salida del ventriculo derecho en 1 paciente y en las cercanias del anillo mitral en otro. En ambos casos, la cartografia y ablacion con exito de la taquicardia se llevo a cabo desde el pericardio mediante un abordaje percutaneo. En el paciente restante, la taquicardia ventricular se originaba tambien cerca del anillo mitral, pero pudo ser ablacionada desde una vena coronaria. Dos pacientes presentaban taquimiocardiopatia y, en ambos, la funcion ventricular izquierda se recupero tras la ablacion. Los intentos fallidos de ablacion endocardica pueden significar la presencia de sustratos arritmicos epicardicos. La ablacion epicardica es eficaz y resulta una alternativa terapeutica en pacientes con taquicardias ventriculares, incluso sin cardiopatia estructural.

Learning Process for Transseptal Puncture Guided by Intracardiac Echocardiography

We prospectively analyzed the learning process for transseptal catheterization guided by intracardiac echocardiography, in 50 patients who underwent radiofrequency ablation for left atrial arrhythmias. In 20 patients the intracardiac echocardiography catheter was positioned in the right atrium to visualize the fossa ovalis and the tenting of the fossa caused by the Brockenbrough needle. In the other 30 patients, the intracardiac echocardiography catheter was positioned so that it impinged upon the fossa ovalis, and the needle was advanced alongside the intracardiac echocardiography catheter under fluoroscopic guidance in two orthogonal projections. In all but one patient, transseptal catheterization was performed successfully on the first attempt. The learning process for transseptal puncture guided by intracardiac echocardiography was uncomplicated, resulting in a procedure that is safe and effective. The intervention is simplified by positioning the echocardiography catheter at the fossa ovalis and using this as a reference point for fluoroscopic monitoring of the progress of the Brockenbrough needle.

Risk Stratification and Prevention of Sudden Death in Patients With Heart Failure

Patients with heart failure can die of progressive refractory heart failure or sudden cardiac death. This article reviews the major clinical predictors of sudden death in patients with heart failure due to left ventricular systolic dysfunction. Although earlier studies have identified many independent univariate predictors of reduced survival in these patients, the positive predictive value of most of them is low. Cardioverter defibrillator implantation has been shown to be the most effective therapy in patients resuscitated after cardiac arrest caused by ventricular fibrillation or poorly tolerated ventricular tachycardia. Low left ventricular ejection fraction, low New York Heart Association functional class, unsustained ventricular tachycardia and inducibility of ventricular arrhythmia in electrophysiological studies may also identify high-risk patients who are candidates for cardioverter defibrillator implantation. The role of amiodarone in preventing sudden death in high-risk patients with heart failure seems to be small. Further studies are needed to improve risk stratification criteria to select patients with heart failure who are candidates for cardioverter defibrillator implantation.

Repercusión cardíaca de la amiloidosis y de la hemocromatosis

Although rare, amyloidosis and hemochromatosis are the infiltrative diseases in which the heart is more frequently involved. The most common clinical presentation is heart failure with hemodynamic features of restrictive heart disease in cardiac amyloidosis. The diagnosis is often made because of symptoms of other organ involvement, although sometimes cardiac symptoms may be the initial manifestation. The non-specific clinical presentation and the low prevalence of these cardiomyopathies make the diagnosis difficult if the clinician does not suspect it. Once symptoms develop, the evolution is fast. Usually, the unsatisfactory and ineffective treatment of amyloidosis and hemochromatosis contribute to the poor prognosis. The indication of cardiac transplantation in advanced cases is questionable because of the high recurrence of the illness.Del grupo de enfermedades infiltrativas y de deposito, la amiloidosis y la hemocromatosis son, dentro de su rareza, las que con mayor frecuencia afectan al corazon. Su forma mas habitual de presentarse es como sindrome de insuficiencia cardiaca, frecuentemente con hemodinamica restrictiva en el caso de la amiloidosis. A menudo el diagnostico se ve facilitado por una historia previa deafectacion de otros organos, pero no es infrecuenteque los primeros en producirse sean sintomas cardiologicos. La inespecificidad en su forma de presentaciony el que se trate de cardiopatias pocoprevalentes, obligan al medico a mantener siempreun alto indice de sospecha para poder diagnosticarlas. Una vez que provocan manifestaciones clinicas,evolucionan muy rapidamente. A su mal pronosticopuede unirse la ausencia de un tratamiento especificoeficaz. La indicacion de trasplante cardiaco en las fases mas avanzadas se ve cuestionada por el alto indice de recurrencias.

Hay un lugar para los fármacos antiarrítmicos

Los farmacos antiarritmicos son un grupo de compuestos heterogeneo, con mecanismos de accion diversos y distintos perfiles de efectos secundarios. En general tienen una eficacia moderada y, en muchas ocasiones, un margen terapeutico estrecho. En algunos casos, pueden incluso resultar letales si no se usan con el adecuado conocimiento. La seleccion del tratamiento esta condicionada por el tipo de arritmia que se va a tratar y el perfil del paciente (especialmente, la cardiopatia de base). Es importante tener en cuenta que, en algunas de las arritmias, la ablacion con cateter o dispositivos como el desfibrilador han resultado ser de eficacia superior que los farmacos antiarritmicos. En la presente revision se analiza el papel de los farmacos en las principales arritmias encontradas en la practica clinica, con especial atencion a la relacion riesgo/beneficio en cada uno de los escenarios clinicos.