14 research outputs found
An谩lisis de regularidad en fibrilaci贸n ventricular: aplicaci贸n a registros de mapeado card铆aco
Las t茅cnicas utilizadas en el an谩lisis de la se帽al de fibrilaci贸n
ventricular (FV), obtenida mediante sistemas de mapeado
utilizando matrices de electrodos, extraen informaci贸n del
proceso a partir de par谩metros calculados principalmente en el
dominio del tiempo o de la frecuencia. El presente trabajo
plantea la aplicaci贸n del 铆ndice de regularidad (IR), propuesto
inicialmente para caracterizar la fibrilaci贸n auricular humana,
a la se帽al de FV en un modelo experimental de coraz贸n animal.
Los resultados obtenidos muestran que el IR permite extraer
informaci贸n de los mapas de FV no disponible de forma directa
cuando se estudian mediante los m茅todos cl谩sicos en el tiempo o
la frecuencia, cuantificando el grado de modificaci贸n en la
morfolog铆a de las ondas de activaci贸n durante la FV
Alteration of Ventricular Fibrillation by Flecainide, Verapamil, and Sotalol
Background鈥擳he 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鈥擳hirty-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卤0.3 versus 2.4卤0.6 cm, P<0.05) and sotalol (2.1卤0.3 versus 2.5卤0.5 cm, P<0.05) prolonged WL and diminished FrD during VF, whereas verapamil (2.0卤0.2 versus 1.7卤0.2 cm, P<0.001) shortened WL and increased FrD. Simple linear regression revealed an inverse relation between FrD and the functional refractory period (r=0.66, P<0.0001), a direct relation with respect to conduction velocity (r=0.33, P<0.01), and an inverse relation with respect to WL estimated during VF (r=0.49, P<0.0001). By stepwise multiple regression, the functional refractory periods were the only predictors of FrD. Flecainide and sotalol increased the circuit size of the reentrant activations, whereas verapamil decreased it. The 3 drugs significantly reduced the percentages of more complex activation maps during VF. Conclusions鈥擳he activation frequency is inversely related to WL during VF, although a closer relation is observed with the functional refractory period. Despite the diverging effects of verapamil versus flecainide and sotalol on the activation frequency, WL, and size of the reentrant circuits, all 3 drugs reduce activation pattern complexity during VF.Chorro Gasco, Francisco Javier, [email protected] ; Guerrero Martinez, Juan Francisco, [email protected] ; Sanchis Fores, Juan, [email protected] ; Such Belenguer, Luis, [email protected]
Modifications on regularity and spectrum of ventricular fibrillation signal induced by physical training
The objective of this work is to study the modifications
on cardiac response during ventricular fibrillation (VF)
induced by physical training. The analysis was performed
in the frequency domain of VF, and the regularity of the
signal was also considered.
Two sets of records were acquired: control (G1:
without physical training, N=10), and trained (G2, N=9).
Cardiac registers were obtained using a 240-electrodes
matrix located on left ventricle of isolated rabbit heart. A
Langendorff system was used to maintain the heart
perfusion. VF was induced by increased frequencies.
To analyze the time course of VF, records were
processed in 4-second segments. For every segment and
channel, Welch periodogram with Hanning window, two
non-overlapped sections and zero padding, was
computed. Parameters considered in frequency domain
are: dominant frequency (DF) and normalized energy
(NE: spectral energy in the window DF卤1Hz, normalized
by spectral energy in 5-35Hz band).
For every segment and channel, a regularity analysis
of VF was performed, obtaining the regularity index (RI),
which is a measure of similarity among local activation
waves present in every channel.
Mean values for the parameters (DF, NE and RI) of
the whole set of electrodes were computed for every
segment. Obtained results show that DF is lower for
trained rabbits (G1: 18.234卤1, 241Hz; G2: 14.370卤0,
866Hz; p<0.001). NE is greater for this group (G1:
0.140卤0.006; G2: 0.263卤0.017; p<0.001), suggesting a
greater spectral concentration around DF. Finally, a
greater regularity has been observed in the fibrillation
signal for trained group (IR, G1: 0.756卤0.026; G2:
0.834卤0.014; p<0.001).
As a summary, the results suggest that both spectral
characteristics and regularity of VF signal are clearly
different for G1 and G2 groups. The trained group (G2)
shows greater regularity, lower DF and spectral
dispersion. These factors should be interpreted as a more
stable cardiac response to V
Analysis of spatial and temporal evolution of regularity maps during ventricular fibrillation
The analysis of cardiac mapping allows investigating
the structure of ventricular fibrillation (VF). This work
analyzes regions of interest (ROI) on cardiac maps
obtained from the regularity analysis of VF records,
providing information about signal regularity at each
time instant and its spatial distribution.
Cardiac registers were obtained using a 240-
electrodes matrix located on left ventricle of isolated
rabbit heart. A Langendorff system was used to maintain
the heart perfusion. VF was induced by increased
frequencies. Two groups of records were considered:
control (G1: without physical training, N=10), and
trained (G2, N=9).
Records were processed in consecutive 4-second
segments. Regularity index (RI) was obtained for every
segment and channel. RI is a measure of similarity
degree among local activation waves for every channel.
A map with the RI value of each channel was computed
for the 82 register segments.
To analyze the spatial distribution of RI, a threshold
value was determined experimentally and applied to the
map in order to obtain the ROI. Two parameters were
calculated: ROI spatial number (ROIsn, a measure of
spatial fragmentation), and ROI spatial area (ROIsa, the
percentage of area map occupied by ROI).
In case of the time course of ROI, two additional
parameters were computed: the number of electrodes
which value had changed respect to the threshold in two
consecutive maps (ROIen, which is related with the
change size), and the cumulative absolute differences of
RI values for the electrodes which are changed (ROIed).
Obtained results for spatial analysis show that the
number of ROI is lower for trained rabbits (ROIsn; G1:
4.465卤1.120; G2: 2.,227卤0.623; p<0.001), but ROI
spatial area is greater than the control group (ROIsa;
G1: 76.235卤5.355%; G2: 88.163卤2.885%; p<0.001).
Time-course analysis shows that more electrodes change
between consecutive maps in the control group (ROIen,
G1: 22.455卤6.702; G2: 13.877卤2.485; p<0.001). No
significant differences were found for ROIed (G1:
18.509卤6.932; G2: 18.619卤4.196; n.s.).
To conclude, ROI analysis on RI maps applied to
trained and no trained rabbits groups shows that VF
cardiac response is more irregular and spatially
fragmented in no trained group. In addition, regularity
maps are more stable with time in trained group
Evoluci贸n de la investigaci贸n cardiol贸gica espa帽ola y an谩lisis comparativo mundial de t贸picos de especial relevancia
Trabajo presentado en el SEC 2019 - El Congreso de las Enfermedades Cardiovasculares, celebrado en Barcelona (Espa帽a), del 17 al 19 de octubre de 2019[Introducci贸n y objetivos] La importancia de la investigaci贸n cardiol贸gica es de tal magnitud y
relevancia que, seg煤n Science Citation Index Expanded (SCIE) de Web of Science Core Collection,
las publicaciones cient铆ficas mundiales se han doblado desde principios de siglo, pasando de
alrededor de 32.000 en 2000 a m谩s de 77.000 en 2018. Nuestro objetivo es identificar temas
relevantes de la medicina cardiovascular y analizar su evoluci贸n anual y comparativa mundial, sus
fuentes de difusi贸n, los grupos de investigaci贸n y su grado de impacto y excelencia. Entre los t贸picos
analizados se encuentran: Implantaci贸n valvular a贸rtica transcat茅ter (TAVI), Tratamiento de
resincronizaci贸n cardiaca (RCT), Nuevos anticoagulantes orales (NACO) y 鈥淪acubitrilo/valsart谩n
(S/V).
[M茅todos] El an谩lisis se realiz贸 en SCIE utilizando perfiles de b煤squeda validados en trabajos
previos y considerando todas las posibles variantes y sin贸nimos de los temas elegidos. Se
seleccionaron los art铆culos originales, revisiones, editoriales y cartas, los cuales se normalizaron y
examinaron mediante t茅cnicas bibliom茅tricas y an谩lisis de redes sociales. Entre los indicadores
calculados se encuentran: el coeficiente de evoluci贸n de la producci贸n nacional frente a mundial, la
media de citas por trabajo y los trabajos m谩s citados.
[Resultados] SCIE incluye 1.572.747 de art铆culos cardiol贸gicos desde 1900 hasta 2018, de los que
36.584 (2,33%) estaban firmados por alguna instituci贸n espa帽ola. La participaci贸n espa帽ola pas贸 del
1,3% en 1990, al 2,5% en 2000 y al 3,5% en 2018. La tabla muestra el n煤merode trabajos para cada
t贸pico seleccionado tanto a nivel mundial como espa帽ol, as铆 como el decalaje entre los primeros
art铆culos publicados a nivel mundial y aquellos con participaci贸n espa帽ola
Relaci贸n de los valores de prote铆na C reactiva con los hallazgos angiogr谩ficos y los marcadores de necrosis en el s铆ndrome coronario agudo sin elevaci贸n del segmento ST
Introducci贸n y objetivos. El mecanismo implicado en la elevaci贸n de la prote铆na C reactiva (PCR) en los s铆ndromes coronarios agudos (inflamaci贸n en la placa de ateroma o necrosis mioc谩rdica) es motivo de controversia. Se investig贸 la relaci贸n de la PCR con la complejidad angiogr谩fica de la lesi贸n causante y con la elevaci贸n de la troponina en el s铆ndrome coronario agudo sin elevaci贸n del segmento ST. Pacientes y m茅todo. Se estudi贸 a 125 pacientes consecutivos con enfermedad de un vaso. Se determinaron la troponina I y la PCR, y se analiz贸 la complejidad angiogr谩fica de la lesi贸n causante (flujo TIMI y trombo). De la historia cl铆nica se recogieron la edad, el sexo, el tabaquismo, la hipertensi贸n, la hipercolesterolemia y la diabetes. Resultados. La distribuci贸n de la PCR por cuartiles evidenci贸 en el cuarto cuartil m谩s pacientes con flujo TIMI 18 mg/l (punto de corte del cuarto cuartil). Cuando fue tratada como una variable continua, una mayor concentraci贸n de PCR tambi茅n se asoci贸 con el trombo (p = 0,02) y con la elevaci贸n de la troponina (p = 0,003). Ninguna variable cl铆nica se relacion贸 con la PCR. Conclusiones. Tanto la complejidad angiogr谩fica de la lesi贸n causante como la elevaci贸n de la troponina est谩n relacionadas con los valores de la PCR en los s铆ndromes coronarios agudos sin elevaci贸n del segmento ST
Estudio de la perfusi贸n coronaria postinfarto mediante an谩lisis cuantitativo de la ecocardiograf铆a mioc谩rdica con inyecci贸n de contraste por v铆a intravenosa
Introducci贸n y objetivos. Tras un infarto de miocardio el da帽o en la microcirculaci贸n indica un peor pron贸stico. Investigamos la utilidad del estudio cuantitativo de la ecograf铆a mioc谩rdica con inyecci贸n de contraste por v铆a intravenosa (EMC-i.v.) para analizar la perfusi贸n coronaria en comparaci贸n con la inyecci贸n intracoronaria (EMC-i.c.). Pacientes y m茅todo. Estudiamos a 42 pacientes con un primer infarto con elevaci贸n del segmento ST, enfermedad de un vaso y arteria abierta (TIMI 3, estenosis 0,75) y EMC-i.v. (perfusi贸n de SonoVue, im谩genes 煤nicas capturando 1 de cada 6 ciclos con trigger en teles铆stole, perfusi贸n normal si > 0,9). Se consider贸 que un paciente ten铆a perfusi贸n alterada si 2 o m谩s segmentos estaban afectados. Resultados. La cuantificaci贸n de EMC-i.v. se realiz贸 en 5 卤 1 min. No se detectaron efectos secundarios. De los 176 segmentos del 谩rea infartada, 141 (80%) presentaron una EMC-i.c. normal y 35 (20%), alterada. Por pacientes, la EMC-i.c. fue normal en 31 (74%) casos y estaba afectada en 11 (26%). Una perfusi贸n normal con EMC-i.v. mostr贸 una sensibilidad del 91%, una especificidad del 84% y un 铆ndice kappa del 0,67 para predecir una perfusi贸n normal con EMC-i.c. (r = 0,86; p < 0,0001 entre ambas t茅cnicas). Conclusiones. Un an谩lisis cuantitativo de im谩genes 煤nicas capturadas durante una perfusi贸n intravenosa de contraste es un m茅todo sencillo, r谩pido y v谩lido para el an谩lisis de la perfusi贸n coronaria postinfarto al compararlo con EMC-i.c