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BACKGROUND: It is believed that QRS dispersion (QRSd) is caused by asynchrony of ventricular activation, but there are no studies that prove it. OBJECTIVES: To determine the mechanism that best explains QRSd in surface electrocardiogram (ECG). METHODS: Cross-sectional study in 95 consecutive patients (median age: 31.0 years [25-52], female sex: 66.3%) with atrioventricular nodal reentrant tachycardia. All 12 ECG leads were recorded at once, simultaneously with the intracardiac recordings. QRSd was quantified as the difference between maximum (QRSmax) and minimum QRS duration (QRSmin). QRS was measured firstly at a calibration of 20 mm/mV and a sweep speed of 50 mm/s, enhancement 10× (basic measurement [BM]), and after at sweep speed of 150 mm/s, enhancement 80 - 160×. The interventricular dyssynchrony (IVD) was also quantified. RESULTS: QRSmax increased from BM (98 ms [91-103]) to 80× (102 ms [99-108]; p = 0.029) and 160× (104 ms [101.5-110]; p = 0.027). QRSmin, almost equaled the duration of QRSmax at 160× (103 ms [100-108]). With BM, QRSd was 26 ms [22-35] and was reduced 26-fold (p < 0.001) by magnifying the QRS at 160× (1 ms [0-3]). IVD was weakly correlated with QRSd (r = 0.234, p = 0.023), but strongly with the total QRS at 160× (r = 0.676, p < 0.001). CONCLUSION: When QRS complex is narrow, the best explanation for the origin of QRSd on the surface ECG is the unequal projection of the ventricular depolarization vector in the different axis of the leads.
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Electrocardiografía , Humanos , Femenino , Adulto , Estudios TransversalesRESUMEN
BACKGROUND: Local theory and the vectorial theory are used to explain the origin of P-wave dispersion (PWD). There are no previous studies that analyze both at the same time. OBJECTIVES: We set out to determine the implication of local and vectorial theories in the origin of PWD. METHODS: Cross-sectional study in 153 randomly selected patients aged 18-70 years, undergoing electrophysiological study. Inhomogeneous atrial conduction was evaluated by atrial electrogram dispersion in terms of duration (EGMdurdis) and morphology (EGMmorph dis). P-distal coronary sinus interval (P-DCS) was also measured. P-wave was measured twice, firstly at a calibration of 20 mm/mV and a sweep speed of 50 mm/s, enhancement 10× (basic measurement [BM]), and second time at sweep speed of 150 mm/s, enhancement 80-160× (high precision measurement [HPM]). RESULTS: PWD with BM was 48 ms [36-54 ms] while with HPM it was 4 ms [0-10 ms], p < 0.001. With BM, maximum and minimum P- wave duration presented a moderate correlation (r = 0.342; p < 0.001), using HPM it becomes strong (r = 0.750; p < 0.001). In cases with P-DCS < 80 ms (r = 0.965; p < 0.001), but not with P-DCS ≥ 80 ms (r = 0.649; p < 0.001), the previous correlation became almost perfect with HPM. EGMdurdis and EGMmorphdis were weak but significantly correlated with PWD. This correlation became moderate in patients with P-DCS ≥ 80 ms and disappeared in those with P-DCS, using BM and HPM. CONCLUSION: Vectorial theory explains almost entirely the PWD phenomenon. Inhomogeneous conduction could be an additional mechanism to explain PWD, but its contribution is small.
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Fibrilación Atrial , Electrocardiografía , Adolescente , Adulto , Anciano , Estudios Transversales , Atrios Cardíacos , Frecuencia Cardíaca , Humanos , Persona de Mediana EdadRESUMEN
OBJECTIVE: Several P-wave parameters reflect atrial conduction characteristics and have been used to predict atrial fibrillation (AF). The aim of this study was to determine the relationship between maximum P-wave duration (PMax) and new P-wave parameters, with atrial conduction times (CT), and to assess their predictive value of AF during electrophysiological studies (AF-EPS). SUBJECTS AND METHODS: This was a cross-sectional study in 153 randomly selected patients aged 18-70 years, undergoing EPS. The patients were divided into 2 groups designated as no AF-EPS and AF-EPS, depending on whether AF occurred during EPS or not. Different P-wave parameters and atrial CT were compared for both study groups. Subsequently, the predictive value of the P-wave parameters and the atrial CT for AF-EPS was evaluated. RESULTS: The values of CT, PMax, and maximum Ppeak-Pend interval (Pp-eMax) were significantly higher in patients with AF-EPS. Almost all P-wave parameters were correlated with the left CT. PMax, Pp-eMax, and CT were univariate and multivariate predictors of AF-EPS. The largest ROC area was presented by interatrial CT (0.852; p < 0.001; cutoff value: ≥82.5 ms; sensitivity: 91.1%; specificity: 81.1%). Pp-eMax showed greater sensitivity (79.5%) to discriminate AF-EPS than PMax (72.7%), but the latter had better specificity (60.4% vs. 41.5%). CONCLUSIONS: Left atrial CT were directly and significantly correlated with PMax and almost all the parameters of the second half of the P-wave. CT, PMax, and Pp-eMax (new parameter) were good predictors of AF-EPS, although CT did more robustly.
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Fibrilación Atrial/diagnóstico , Electrocardiografía/métodos , Adulto , Anciano , Electrofisiología Cardíaca , Estudios Transversales , Femenino , Atrios Cardíacos , Sistema de Conducción Cardíaco , Humanos , Masculino , Persona de Mediana EdadRESUMEN
Objectives: Due to their anti-inflammatory and immunosuppressive effects, topical corticosteroids (TCs) are commonly used for the treatment of patients with oral lichen planus (OLP) with an erosive or ulcerative component. It has been suggested that many of these patients may suffer from fear or anxiety as a result of prolonged treatment with TCs. The objective of this study was twofold: (1) to optimise a patient reported outcome measure (PROM) in order to explore this feature, and (2) to evaluate this PROM in the treatment of OLP patients.Methods: A group of qualitative researchers adapted the TOPICOP questionnaire in order for it to be used as a PROM for OLP via structural equation modelling (SEM) and internal consistency (IC) analysis. Consequently, 34 patients with symptomatic OLP who were undergoing treatment with TCs completed a questionnaire and underwent a clinical assessment.Results: SEM presented an adequate fit (RMSA = 0.07, CFI = 0.94 and WRMR = 1.18), as well as a high IC (α = 0.81). A total of 16 patients (47.1%) reported TCs phobia. The receiver operating characteristic analysis (ROC) revealed that a TOPICOP value ≥50% predicted the presence of TCs phobia with a sensitivity of 93% and a specificity of 100%.Conclusions: The optimised TOPICOP scale proved valuable as a PROM in OLP. TCs phobia can be a real consideration in OLP, nonetheless, it does not appear to be an impediment to treatment adherence.
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Liquen Plano Oral , Trastornos Fóbicos , Ansiedad , Humanos , Liquen Plano Oral/diagnóstico , Liquen Plano Oral/tratamiento farmacológico , Reproducibilidad de los Resultados , Encuestas y CuestionariosRESUMEN
BACKGROUND: Oblique course of some left accessory pathways is rare An incomplete electrophysiological study may confuse us between an oblique accessory pathway or the presence of two accessory pathways. The proximity of all atrial and ventricular electrograms, at each pole of the catheter, within the coronary sinus may be a novel finding. CASE PRESENTATION: A 68-year-old woman patient presented arrhythmias with hypotension requiring electrical cardioversion. Her electrocardiogram (ECG) was interpreted as atrial fibrillation by accessory pathway. We performed with the protocol of ablation stablished in our laboratory: two punctures on the right femoral vein with placement of introducers (8F and 7F) by Seldigner technique and one puncture on the left femoral vein (7F). The study was performed with BIOTRONIK technology (Multicath study catheter), a non-deflectable 7F quadripolar catheter with 2 mm tip electrode to record the His electrogram, a non-deflectable decapolar catheter with 5 pairs of coronary sinus (CS) electrodes. Accessory pathway mapping was performed in right and left cavities and within the CS. All electrograms into CS showed short AV from proximal to distal CS. Finally, ablation of two accessory pathway recordings was achieved at two distant epicardial points within the CS. CONCLUSIONS: Ablation at two distant sites, one on the ventricular side and the other on the mitral annulus, suggests the presence of an oblique accessory pathway and at the same time the differential diagnosis of the presence of two accessory pathways. In our point of view according the above, we consider this is a very rare case of oblique AP with epicardial trajectory. The sequence of electrograms (in this case) along the CS has not been seen before in the literature reviewed. It is important, regardless of the urgency, to follow diagnostic and therapeutic protocols in invasive electrophysiology.
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BACKGROUND: Permanent right ventricular apical pacing may have negative effects on ventricular function and contribute to development of heart failure. We aimed to assess intra- and interventricular mechanical dyssynchrony in patients with permanent right ventricular apical pacing, and to establish electrocardiographic markers of dyssynchrony. METHODS: 84 patients (46:38 male:female) who required permanent pacing were studied. Pacing was done from right ventricular apex in all patients. We measured QRS duration and dispersion on standard 12-lead ECG. Intra- and interventricular mechanical dyssynchrony and left ventricular ejection fraction were assessed by transthoracic echocardiography. Patients were followed-up for 24 months. Results: Six months after implantation, QRS duration increased from 128.02 ms to 132.40 ms, p≤0.05. At 24 months, QRS dispersion increased from 43.26 ms to 46.13 ms, p≤0.05. Intra- and interventricular dyssynchrony increased and left ventricular ejection fraction decreased during follow-up. A QRS dispersion of 47 ms predicted left ventricular dysfunction and long-term electromechanical dyssynchrony with a sensitivity of 80% and a specificity of 76%. Conclusion: In patients with permanent right ventricular apical pacing there is an increased duration and dispersion of QRS related to dyssynchrony and decreased left ventricular ejection fraction. This study shows that QRS dispersion could be a better predictive variable than QRS duration for identifying left ventricular ejection fraction worsening in patients with permanent right ventricular apical pacing. The electrocardiogram is a simple tool for predicting systolic function worsening in these patients and can be used at the bedside for early diagnosis in the absence of clinical symptoms, allowing adjustments of medical treatment to prevent progression of heart failure and improve the patient's quality of life.
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BACKGROUND: P-wave dispersion (PWD) is believed to be caused by inhomogeneous atrial conduction. This statement, however, is based on limited little solid evidence. The aim of this study was to determine the relationship between atrial conduction and PWD by means of invasive electrophysiological studies. METHODS: Cross-sectional study in 153 patients with accessory pathways and atrioventricular node reentry tachycardia (AVNRT) undergoing an electrophysiological study. Different atrial conduction times were measured and correlated with PWD. RESULTS: Only the interatrial (P-DCS) and left intra-atrial conduction times (ΔDCS-PCS) showed a significant correlation with PWD, but this correlation was weak. Multivariate linear regression analysis determined that both P-DCS (ß = 0.242; P = .008) and ΔDCS-PCS (ß = 0.295; P < .001) are independent predictors of PWD. Performing the multivariate analysis for arrhythmic substrates, it is observed that only ΔDCS-PCS continued to be an independent predictor of PWD. Analysis of the receiver operating characteristic curves showed that regardless of the types of arrhythmic substrates, PWD discriminates significantly, but moderately, to patients with P-DCS and ΔDCS-PCS ≥75 percentile. CONCLUSIONS: Interatrial and intraleft atrial conduction times were directly and significantly correlated with PWD, but only weakly, and were independent predictors of PWD. In general, PWD correctly discriminates patients with high values in interatrial and intraleft atrial conduction times, but moderately. This is maintained in cases with accessory pathways; however, in patients with AVNRT it only does so for intraleft atrial conduction times. Interatrial and intraleft atrial conduction times weakly explains PWD.
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El descubrimiento de la electrocardiografía marcó un hito para la medicina: ofreció una mejor comprensión de la fisiología cardiovascular, es una herramienta imprescindible para el diagnóstico, evaluación y estratificación pronóstica de casi la totalidad de las enfermedades cardiovasculares, y ha sido un componente insustituible de las investigaciones cardiológicas de la medicina contemporánea. Importantes investigaciones de la cátedra de Cardiología del Hospital Universitario Cardiocentro "Ernesto Guevara" la han tenido como objeto de estudio en consonancia con las directrices del sistema de salud, para su aplicación en la asistencia y la actualización de los programas de la especialidad, los que se han enriquecido con nuevas variables electrocardiográficas denominadas como "no clásicas". Es objetivo de los autores comunicar algunos resultados científicos novedosos de investigaciones relacionadas con este vetusto medio de diagnóstico, los que han sido publicadas en revistas de alto impacto.
The discovery of electrocardiography marked a milestone for medicine: it offered a better understanding of cardiovascular physiology and has been an essential tool for the diagnosis, evaluation, and prognostic stratification of almost all cardiovascular diseases, and it has been an irreplaceable component of cardiology research in contemporary medicine. Important investigations of the Cardiology professorship of the "Ernesto Guevara" University Hospital have had it as an object of study in line with the guidelines of the health system, for its application in assistance and updating of specialty programs, which have been enriched with new electrocardiographic variables called "non-classical". It is the objective of the authors to communicate some novel scientific results of investigations related to this ancient aid of diagnosis, which have been published in high-impact journals.
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Calidad de la Atención de Salud , Cardiología , Educación Médica , ElectrocardiografíaRESUMEN
RESUMEN Introducción: Existen algunos estudios que relacionan parámetros de la onda P con diferentes tiempos de conducción auricular, pero no se han realizado teniendo en cuenta a cada derivación del electrocardiograma. Objetivo: Determinar la duración de la onda P (Pdur) en las 12 derivaciones y relacionarlas con el tiempo de conducción interauricular. Método: Estudio de corte transversal en 153 pacientes adultos con diagnóstico confirmado de taquicardia por reentrada intranodal (TRIN) o vías accesorias mediante estudio electrofisiológico invasivo. Resultados: Al comparar la Pdur entre sustratos arrítmicos por cada derivación, no existieron diferencias significativas, excepto en V6. En las derivaciones DII, DIII, aVR, aVF, V1 y de V3-V6 la Pdur se correlacionó con el tiempo de conducción interauricular en ambos sustratos arrítmicos. En el análisis multivariado, la Pdur constituyó un predictor independiente de tiempos de conducción interauricular ≥ 95 percentil, en las derivaciones de cara inferior y en V3, V5 y V6. Se observaron altos valores del área bajo la curva de la Característica Operativa del Receptor en las derivaciones DII (0,950; p<0,001), DIII (0,850; p<0,001) y V5 (0,891; p<0,001). Conclusiones: No existen diferencias por derivación en la Pdur al comparar casos con TRIN y vías accesorias, excepto en V6. La mayoría de las derivaciones se correlacionaron con el tiempo de conducción interauricular. La Pdur fue un predictor independiente de tiempos de conducción interauricular ≥ 95 percentil. La derivación DII presenta la mayor capacidad discriminativa para encontrar valores prolongados del tiempo de conducción interauricular.
ABSTRACT Introduction: Although some studies relate P wave parameters to different atrial conduction times, they do not consider each electrocardiogram lead separately. Objective: To determine the duration of P wave (Pdur) in the 12 leads of the electrocardiogram and relate it to the interatrial conduction time. Method: We conducted a cross-sectional study in 153 adult patients with confirmed diagnosis of atrioventricular nodal reentry tachycardia (AVNRT) or accessory pathways by invasive electrophysiological study. Results: When comparing the Pdur between arrhythmic substrates by each lead, no significant differences were found, except for V6. In leads II, III, aVR, aVF, V1 and V3-V6, Pdur was correlated with the interatrial conduction time in both arrhythmic substrates. In our multivariate analysis, the Pdur was an independent predictor of interatrial conduction times ≥ 95 percentile in inferior wall leads and in V3, V5 and V6. High values of the area under the receiver operating characteristic curve were observed in II (0.950; p<0.001), III (0.850; p<0.001) and V5 (0.891; p<0.001) leads. Conclusions: The Pdur showed no difference by leads when comparing cases with AVNRT and accessory pathways, except for V6. Most of the leads were correlated with the interatrial conduction time; Pdur was an independent predictor of interatrial conduction times ≥ 95 percentile. Lead II has the greatest discriminatory ability to find prolonged values of interatrial conduction time.
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Taquicardia , Técnicas Electrofisiológicas Cardíacas , Electrocardiografía , Fascículo Atrioventricular AccesorioRESUMEN
Introducción: A pesar de los indiscutibles beneficios en cuanto a calidad y expectativa de vida en los pacientes con indicaciones precisas de marcapasos, existen un grupo de ellos con efectos deletéreos en la función y geometría ventricular izquierda. Objetivo: Identificar modificaciones ecocardiográficas en pacientes con estimulación cardíaca permanente realizada desde punta de ventrículo derecho. Métodos: Se realizó estudio descriptivo longitudinal prospectivo a 84 pacientes que requirieron implantación de marcapasos permanente con estimulación desde punta del ventrículo derecho. Se recolectaron datos ecocardiográficos antes y después del implante. Resultados: El 53,65 por ciento fueron del sexo masculino, edad media 68,25. Las medias de las variables ecocardiográficas incrementaron sus valores, excepto, la fracción de eyección del ventrículo izquierdo que disminuyó, el grupo con estimulación secuencial presentó 4 casos más con disfunción diastólica grado II que al inicio, el grupo con estimulación no secuencial tuvo 5 casos con disfunción diastólica grado III, la fracción de eyección del ventrículo izquierdo disminuye un 6 por ciento en pacientes con estimulación secuencial y 9 por ciento para el modo no secuencial. Conclusiones: Las modificaciones ecocardiográficas durante el estudio mostraron una tendencia grupal al aumento excepto la fracción de eyección del ventrículo izquierdo que disminuyó(AU)
Introduction: Despite their indisputable benefits for the quality of life and life expectancy of patients with precise pacemaker indications, a number of these devices have shown to have deleterious effects in terms of left ventricular function and geometry. Objective: Identify echocardiographic changes in patients with permanent cardiac stimulation applied from the right ventricular tip. Methods: A prospective longitudinal descriptive study was conducted of 84 patients requiring permanent pacemaker implantation with stimulation from the right ventricular tip. Echocardiographic data were collected before and after implantation. Results: Of the total patients, 53.65 percent were male. Mean age was 68.25 years. An increase was observed in all the means of echocardiographic values except for the left ventricular ejection fraction, which decreased. The sequential stimulation group presented 4 more cases with grade II diastolic dysfunction than at baseline, whereas the group with non-sequential stimulation included 5 grade III diastolic dysfunction cases. Left ventricular ejection fraction lowered 6 percent in patients with sequential stimulation and 9% in patients with non-sequential stimulation. Conclusions: Echocardiographic changes during the study showed a group tendency to increase, except for the left ventricular ejection fraction, which decreased(AU)