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La insuficiencia cardíaca presenta en la actualidad altas tasas de morbilidad y mortalidad. Diferentes modelos fisiopatológicos intentaron explicar esta enfermedad, a partir de los cuales se evaluó la eficacia y seguridad de distintas drogas para el tratamiento médico de la falla cardíaca. A pesar de ello, las altas tasas de mortalidad y rehospitalizaciones por insuficiencia cardíaca aguda se mantienen. El advenimiento de la terapia de resincronización cardíaca intenta restaurar la performance de la función ventricular al mejorar la sincronía en la contracción. Los estudios clínicos randomizados que evaluaron esta modalidad terapéutica fueron concluyentes al demostrar mejoría de los parámetros clínicos y disminuir la mortalidad pero aún son necesarios otros estudios para precisar los criterios para una más adecuada selección de los pacientes que se beneficiarán con esta terapia.

Heart failure is currently presenting high rates of morbidity and mortality. Different pathophysiological models tried to explain this disease, and with them different drugs were evaluated for the treatment of heart failure. However, heart failure remains with high post discharge rates of mortality and readmission for acute heart failure. Myocardial injury produces conduction system disturbances, with abnormal ventricular depolarization. Cardiac resynchronization therapy attempts to restore ventricular function performance by improving ventricular contraction synchrony. The results of randomized clinical trials to assess this therapy showed improvements in clinical parameters and decrease mortality. Although cardiac resynchronization therapy, associated with optimal medical treatment, showed improvements in heart failure patients, new trials are still necessary to select the optimal criteria for the patients who will more benefit with this kind of therapy.

La detección de fibrilación ventricular (FV) por medio de algoritmos apropiados es crítica en la funcionalidad de los cardiodesfibriladores automáticos externos. Una de las técnicas más recientes y efectivas reportadas en la literatura médica es la reconstrucción de espacio de fase (REF), basada en el comportamiento caótico y no linear del electrocardiograma. En este trabajo se propone un nuevo algoritmo basado en la REF para la detección de la FV considerando retardos variables, el cual señala las diferencias entre una señal normal y una señal irregular correspondiente a FV. La evaluación y validación del algoritmo se realizó mediante registros de la base de datos de arritmias del Instituto Tecnológico de Massachusetts y del Hospital Beth Israel, así como de la base de datos de arritmias ventriculares sostenidas de la Universidad de Creighton. Los resultados han demostrado una mejora en términos de sensibilidad, especificidad, predicción positiva y exactitud respecto de otros algoritmos evaluados en condiciones similares.

Detection of ventricular fibrillation (VF) by means of appropriate algorithms is crucial for automatic external defibrillators function. One of the more recent and effective technique reported in scientific literature is the phase space reconstruction (PSR) which is based on the non-linear and chaotic behaviour of the electrocardiogram. It is proposed in this work a novel PSR based algorithm for VF detection considering variable delay times which stresses the differences between normal signals and irregular signals of VF. The evaluation and validation of the algorithm was made with records of the Massachusetts Institute of Technology, the Beth Israel Hospital and the Creighton University arrythmia databases. The results have shown improvement in terms of sensitivity, specificity, positive predictive value, and accuracy in respect to other algorithms evaluated under similar conditions.

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Utilidad diagnóstica del tilt test sin fase pasiva y sensibilizado con dinitrato de isosorbide en pacientes con sospecha de síncope vasovagal.
Diagnostic value of isosorbide dinitrate-stimulated tilt test without the prior passive phase in patients with suspected vasovagal syncope.
OSCAR A. PELLIZZÓN, ANTONIA CATALANO, IDELMO NICOLA, CARLOS ALBINOLI, STELLA PEZZOTTO

El aporte de la fase pasiva a un protocolo de tilt test estimulado con dinitrato de isosorbide parece ser de poca ayuda. Se investigó la utilidad diagnóstica de un tilt test sin fase pasiva y sensibilizado con dinitrato de isosorbide sublingual en pacientes con sospecha de síncope vasovagal. El protocolo utilizado demostró ser exacto, sensible, breve, fácil de realizar y con un alto valor predictivo positivo para provocar reacciones vasovagales. La utilidad diagnóstica de este protocolo sería semejante a la de aquellos de mayor duración.

The contribution of the passive phase for the tilt test protocol stimulated with isosorbide dinitrate may be of low value. We investigated the diagnostic value of sublingual isosorbide dinitrate without the preceding passive tilt phase in patients with suspected vasovagal syncope.
Material and method. Seventy six patients (mean age 39.6±2.4 years) with clinically suspected vasovagal syncope and 18 healthy volunteers (mean age 46.1±5.4 years) were studied. Patients were studied in a motorized table at 60° and after attaining erect posture 1.25 mg of sublingual isosorbide dinitrate was administered. Sensitivity, specificity, positive and negative predictive value and overall value of the test were calculated.
Results. The tilt test was positive in 46/76 cases and in 8/18 controls. The time between the administration of sublingual isosorbide dinitrate and syncope development was 5.4±0.6 min and 4.6±1.4 min, for cases and the controls, respectively (NS). Estimates were as follows: sensitivity 61.8% (IC95% 49.9-72.5), specificity 55.6% (IC95% 31.3-77.6), positive predictive value 85.5% (IC95% 72.8-93.1), negative predictive value 25.6% (IC95% 13.6-42.4) and overall test value 60.6% (IC95% 50-70.4).
Conclusions. Sublingual dinitrate isosorbide stimulated tilt protocol without a prior passive phase proved to be accurate, sensitive, quick and easy to perform; yielding a high positive predictive value to provoke vasovagal reactions. The diagnostic value of this protocol may be similar to those of longer duration.

Supervivencia tras la parada cardiorrespiratoria después de la implementación de un programa de reanimación intrahospitalaria.
Outcome of cardiac arrests after implementation of hospital resuscitation program.
MARTA S. LÓPEZ RODRÍGUEZ, BEATRIZ VALLONGO MENÉNDEZ, SARA FERNÁNDEZ ABREU, JOSÉ GUNDIAN PIÑEIRA, VÍCTOR NAVARRETE ZUAZO, MARIETA DE LA BARRERA FERNÁNDEZ

La evaluación del resultado del paro cardíaco conduce a determinar la supervivencia. La instalación de un programa de reanimación intrahospitalaria es clave para la misma. El objetivo del presente trabajo fue determinar la supervivencia después de la implementación de un programa de reanimación intrahospitalario en la Clínica Central Cira García (Cuba). La supervivencia fue alta en relación con los estándares internacionales. Los factores relacionados con la supervivencia fueron: paro presenciado, lugar en que se produjo el evento, ritmo inicial, intervalos de respuesta, puntaje de Glasgow y capacidad funcional cerebral.

The implementation of a hospital cardiopulmonary resuscitation program is key for obtain appropriate outcome. The aim of our study was to determine outcomes after the implementation of a resuscitation program. Methods: A cuasi experimentally study was conducted in the Cira García Clinic from January, 2004 to December, 2006. The study group consisted of the all patients with in-hospital cardio respiratory arrest. The systematic compilation of the data was carried out by the observation, interview and written questionnaire. The studied variables were recorded according to in-hospital resuscitation UTSTEIN style. The population of patients was characterized by using descriptive statistics. Two entries statistical scores were made up taking in count several variables of interest with relation to changeable discharge of patients. Kaplan Meier’s method was used to evaluate the probability of survival. Results: The survival was 56.5 %. Conclusions:  Survival rate at hospital discharge is high in relation to international standards. The factors related with the survival are: witnessed cardiac arrest, location of cardiac arrest, first cardiac rhythm, intervals of response and functional cerebral capacity.

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Importancia de la hipertrofia ventricular izquierda inapropiada en la regresión del daño en órgano blanco.
Importance of inappropriate left ventricular mass in the regression of left ventricular hypertrophy.
DANIEL PISKORZ, ALICIA S. TOMMASI

La hipertrofia ventricular izquierda inapropiada es el incremento del índice de masa ventricular izquierda más allá de lo esperable para la carga de trabajo, en 201 pacientes hipertensos seguidos durante un año. El objetivo de este trabajo fue determinar la importancia de la hipertrofia ventricular izquierda de tipo inapropiada sobre la regresión del índice de masa ventricular izquierda. Se concluye que: 1) la hipertrofia ventricular izquierda inapropiada podría deberse a un incremento en la presión de pulso más que a la carga de trabajo; 2) la regresión del índice de masa ventricular izquierda observada en la hipertrofia inapropiada es insuficiente para alcanzar los valores considerados normales.

Inappropriate left ventricular mass is the increase of left ventricular mass index beyond what is expected for the workload.
Objectives. To determine in hypertensive patients the importance of having inappropriate left ventricular mass on the regression of left ventricular hypertrophy.
Material and methods. Two hundred and one hypertensive patients starting treatment and follow up for 1 year. Left ventricular mass index was measured by Devereux method at baseline and after a year of treatment, and concordance of observed to predicted left ventricular mass ratio was calculated by De Simone method. Left ventricular mass index > 50 gr/m2.7 was considered left ventricular hypertrophy. Observed to predicted left ventricular mass ratio > 128% was considered inappropriate. Three groups were compared: A) patients without left ventricular hypertrophy; B) patients with appropriate left ventricular hypertrophy; C) patients with inappropriate left ventricular hypertrophy. Statistical analysis: variance test; statistical significance p < 0.05.
Results. There were 93 patients (46%) in group A, 71 patients (35%) in group B, and 37 patients (19%) in group C. The mean age was 53 ± 14 years; 55 ± 12 years; and 62 ± 12 years, and female frequency was 47 patients (51%), 20 patients (28%), and 32 patients (87%) (p < 0.0001) for groups A, B y C, respectively. The pulse pressure was 61 ± 18 mmHg, 66 ± 21 mmHg and 74 ± 18 mmHg, respectively (p < 0.003 group C vs A and B). The stroke volume was 70.4 ± 15.2 mL, 83.9 ± 19.1 mL, and 79.4 ± 18.6 mL, respectively (p < 0.005 groups B and C vs A). No differences were found in workload and systolic and diastolic blood pressure. The baseline left ventricular mass index was 39.5 ± 6.8 gr/m2.7, 60.6 ± 9.2 gr/m2.7, and 73.3 ± 13.4 gr/m2.7, respectively (p < 0.0001). At one year follow up under optimal treatment, left ventricular mass index was +1.7 ± 8.7 gr/m2.7, -5.3 ± 13 gr/m2.7, and -8.4 ± 14.8 gr/m2.7, respectively (p < 0.0001 groups B and C vs A).
Conclusions. 1) Left ventricular hypertrophy with inappropriate left ventricular mass would be a consequence of an increased pulse pressure rather than an increased workload. 2) The reduction of left ventricular mass index observed in patients with left ventricular hypertrophy and inappropriate left ventricular mass is insufficient to achieve normal values of left ventricular mass index.

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El ventrículo izquierdo no compactado es una forma de miocardiopatía no clasificable. Se produce en la vida fetal a causa de una detención del proceso normal de compactación de la pared ventricular, y se caracteriza por la presencia de una extensa capa trabeculada, con múltiples recesos, sobre el lado endocavitario. Se identifican formas familiares y aisladas, debido a heterogeneidad genética, documentándose mutaciones genéticas diversas. Clínicamente se manifiesta con insuficiencia cardíaca, arritmias y tromboembolismo sistémico. En la actualidad no existe un tratamiento específico; se tratan la insuficiencia cardíaca y las complicaciones. En el futuro será promisoria la terapia génica. Presentamos un caso clínico con insuficiencia cardíaca severa.

The left non compacted ventricle is a form of non-classifiable myocardiopathy. It occurs in the fetal stage, caused by a detention of the normal process of compactation of the ventricular wall, presenting a large trabecular layer, with multiple recesses on the endocavity side. It is possible to identify isolated and familiar forms (20%-50% of the cases) due to genetic heterogeneity with documented proof of diverse genetic mutations.
Clinically, it appears through cardiac insufficiency, arrhytmias and systemic thromboembolism. There is no clinical case of severe cardiac insufficiency.
The diagnosis by echocardiography reveals a relationship between the thick, non compacted leyer and the compacted myocardium > 2, being possible to visualize the blood flow by color Doppler, in the prominent intertrabecular separations. The cardiac magnetic resonance diagnosis, through the sequence called "steady state free precession". Nowadays, there is no specific treatment. The cardiac insufficiency and the complications are theated; in the future, the genetic therapy will be promissory though.

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Se presenta el caso de una mujer de 28 años, con historia de disnea y palpitaciones. El ecocardiograma reveló la presencia de múltiples masas heterogéneas, pediculadas, móviles en el interior del ventrículo izquierdo. El eco convencional Doppler y codificado a color demostró obstrucción del tracto de entrada y de salida del ventrículo izquierdo, causada por las masas intracavitarias, lo cual producía un gradiente de presión transmitral de 20 mmHg, y de 85 mmHg entre la aorta y el ventrículo izquierdo. Se realizó cirugía cardíaca, resecando cinco masas tumorales conjuntamente con su base de implantación. El estudio anatomopatológico de las piezas quirúrgicas confirmó que se trataba de mixomas.

In this report we describe the case of a 28 year-old woman who had dypsnea and palpitations. We performed transthoracic echocardiography, that showed multiple mobile masses in the left ventricle, attached to the endocardial surface by a narrow stalk. Conventional and color Doppler examination revealed left ventricular inflow and outflow tract obstruction caused by the masses that produced a transmitral pressure gradient of 20 mmHg, and 85 mmHg between the aorta and left ventricle. Open heart surgery was performed. Five masses were removed, and histologic examination confirmed the myxomal etiology.

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Publicación: Agosto 2009