RESUMEN
Classification of atrial fibrillation (AF) is currently based on clinical characteristics. However, classifying AF using an objective electrophysiological parameter would be more desirable. The aim of this study was to quantify parameters of atrial conduction during sinus rhythm (SR) using an intra-operative high-resolution epicardial mapping approach and to relate these parameters to clinical classifications of AF. Patients were divided according to the standard clinical classification and spontaneous termination of AF episodes. The HATCH score, a score predictive of AF progression, was calculated, and surface ECGs were evaluated for signs of interatrial block. Conduction disorders mainly differed at Bachmann's bundle (BB). Activation time (AT) at BB was longer in persistent AF patients (AT-BB: 75 (53-92) ms vs. 55 (40-76) ms, p = 0.017), patients without spontaneous termination of AF episodes (AT-BB: 53.5 (39.6-75.8) ms vs. 72.0 (49.6-80.8) ms, p = 0.009) and in patients with a P-wave duration ≥ 120 ms (64.3 (52.3-93.0) ms vs. 50.5 (39.6-56.6) ms, p = 0.014). HATCH scores also correlated positively to AT-BB (rho 0.326, p = 0.029). However, discriminatory values of electrophysiological parameters, as calculated using ROC-curves, were limited. These results may reflect shortcomings of clinical classifications and further research is needed to establish an objective substrate-based classification of AF.
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Endo-epicardial asynchrony (EEA) is a new mechanism possibly maintaining atrial fibrillation. We aimed to determine the sensitivity and best recording modus to detect EEA on electrograms recorded from one atrial side using electrogram fractionation. Simultaneously obtained right atrial endo- and epicardial electrograms from 22 patients demonstrating EEA were selected. Unipolar and (converted) bipolar electrograms were analyzed for presence and characteristics of fractionation corresponding to EEA. Sensitivity of presence of EEA corresponding fractionation was high in patients (86-96%) and moderately high (65-78%) for the asynchronous surface area for unipolar and bipolar electrograms equally. In bipolar electrograms, signal-to-noise ratio of EEA corresponding fractionation decreased and additional fractionation increased for electrograms recorded at the endocardium. Sensitivity of fractionation corresponding to EEA is high for both unipolar and bipolar electrograms. Unipolar electrograms are more suited for detection of EEA due to a larger signal-to-noise ratio and less disturbance of additional fractionation. Unipolar electrograms are more suited than bipolar electrograms to detect endo-epicardial asynchrony on one side of the atrial wall using electrogram fractionation.
Asunto(s)
Fibrilación Atrial , Atrios Cardíacos , Fibrilación Atrial/diagnóstico , Electrocardiografía , Endocardio , HumanosRESUMEN
Background The significance of endo-epicardial asynchrony (EEA) and atrial conduction block (CB), which play an important role in the pathophysiology of atrial fibrillation (AF) during sinus rhythm is poorly understood. The aim of our study was therefore to examine 3-dimensional activation of the human right atrium (RA). Methods and Results Eighty patients (79% men, 39% history of AF) underwent simultaneous endo-epicardial sinus rhythm mapping of the inferior, middle and superior RA. Areas of CB were defined as conduction delays of ≥12 ms, EEA as activation time differences of opposite electrodes of ≥15 ms and transmural CB as CB at similar endo-epicardial sites. CB was more pronounced at the endocardium (all locations P<0.025). Amount, extensiveness and severity of CB was higher at the superior RA. Transmural CB at the inferior RA was associated with a higher incidence of post-operative AF (P=0.03). EEA occurred up to 84 ms and was more pronounced at the superior RA (superior: 27 ms [interquartile range, 18.3-39.3], versus mid-RA: 20.3 ms [interquartile range, 0-29.9], and inferior RA: 0 ms [interquartile range, 0-21], P<0.001). Hypertension (P=0.009), diabetes mellitus (P=0.018), and hypercholesterolemia (P=0.015) were associated with a higher degree of EEA. CB (P=0.007) and EEA (P=0.037) were more pronounced in patients with a history of persistent AF compared with patients without AF history. Conclusions This study provides important insights into complex atrial endo-epicardial excitation. Significant differences in conduction disorders between the endo- and epicardium and a significant degree of EEA are already present during sinus rhythm and are more pronounced in patients with cardiovascular risk factors or a history of persistent AF.
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Fibrilación Atrial/fisiopatología , Mapeo Epicárdico/métodos , Atrios Cardíacos/fisiopatología , Sistema de Conducción Cardíaco/fisiopatología , Anciano , Anciano de 80 o más Años , Trastorno del Sistema de Conducción Cardíaco/fisiopatología , Complicaciones de la Diabetes/fisiopatología , Electrofisiología/métodos , Endocardio/fisiopatología , Femenino , Bloqueo Cardíaco/fisiopatología , Factores de Riesgo de Enfermedad Cardiaca , Humanos , Hipercolesterolemia/complicaciones , Hipercolesterolemia/fisiopatología , Hipertensión/complicaciones , Hipertensión/fisiopatología , Masculino , Persona de Mediana Edad , Pericardio/fisiopatología , Índice de Severidad de la EnfermedadRESUMEN
The predisposition of atrial extrasystoles (AES) to trigger cardiac tachyarrhythmia may arise from intramural conduction disorders causing endo-epicardial asynchrony (EEA). This study aimed to determine whether spontaneous AES disturb endo-epicardial conduction. Simultaneous endo-epicardial mapping of the right atrium was performed in patients during cardiac surgery with two 128-electrode arrays. Sixty spontaneous AES were observed in 23 patients and were analyzed for incidence of conduction delay, conduction block and amount of EEA compared to the previous sinus rhythm beat. Both conduction delay and block occurred more often in AES compared to sinus rhythm. The difference in lines of conduction block between the epicardium and endocardium increased in AES causing a greater imbalance of conduction disorders between the layers. The incidence of EEA with differences ≥10 ms increased significantly in AES. AES caused delays between the epicardium and endocardium up to 130 ms and EEA to increase for up to half (47%) of the mapping area. Conduction disturbances between the epicardial and endocardial layer giving rise to EEA increase during AES. Asynchronous activation of the atrial layers increases during AES which may be a mechanism for triggering cardiac tachyarrhythmia under the right conditions but EEA cannot be recognized by current mapping tools.
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Different arrhythmogenic substrates for atrial fibrillation (AF) may underlie aortic valve (AV) and mitral valve (MV) disease. We located conduction disorders during sinus rhythm by high-resolution epicardial mapping in patients undergoing AV (n = 85) or MV (n = 54) surgery. Extent and distribution of conduction delay (CD) and block (CD) across the entire right and left atrial surface was determined from circa 1880 unipolar electrogram recordings per patient. CD and CB were most pronounced at the superior intercaval area (2.5% of surface, maximal degree 6.6%/cm2). MV patients had a higher maximal degree of CD at the lateral left atrium than AV patients (4.2 vs 2.3%/cm2, p = 0.001). A history of AF was most strongly correlated to CD/CB at Bachmann's bundle and age. Although MV patients have more conduction disorders at the lateral left atrium, disturbed conduction at Bachmann's bundle during sinus rhythm indicates the presence of atrial remodeling which is related to AF episodes.
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Estenosis de la Válvula Aórtica/cirugía , Válvula Aórtica/cirugía , Fibrilación Atrial/etiología , Procedimientos Quirúrgicos Cardíacos/efectos adversos , Atrios Cardíacos/fisiopatología , Frecuencia Cardíaca , Insuficiencia de la Válvula Mitral/cirugía , Válvula Mitral/cirugía , Potenciales de Acción , Factores de Edad , Anciano , Válvula Aórtica/fisiopatología , Estenosis de la Válvula Aórtica/complicaciones , Estenosis de la Válvula Aórtica/diagnóstico , Estenosis de la Válvula Aórtica/fisiopatología , Fibrilación Atrial/diagnóstico , Fibrilación Atrial/fisiopatología , Mapeo Epicárdico , Femenino , Humanos , Masculino , Persona de Mediana Edad , Válvula Mitral/fisiopatología , Insuficiencia de la Válvula Mitral/complicaciones , Insuficiencia de la Válvula Mitral/diagnóstico , Insuficiencia de la Válvula Mitral/fisiopatología , Factores de Riesgo , Resultado del TratamientoRESUMEN
We report a 37-year-old woman with an out-of-hospital cardiac arrest caused by ventricular fibrillation due to digenic inheritance of long QT syndrome type 2 (KCNH2 gene) and type 6 (KCNE2 gene). During hospitalization, prolonged QTc intervals and frequent episodes of ventricular tachyarrhythmias manifested. Genetic testing identified a mutation of the KCNH2 gene and an unclassified variant, most likely pathogenic, of the KCNE2 gene. This digenic inheritance is extremely rare.
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Risk stratification is the most challenging part in management of patients with Brugada syndrome (BrS). Conduction delay in the right ventricular outflow tract (RVOT) is the major mechanism underlying ventricular tachyarrhythmia (VTA) in BrS. However, QRS duration was not useful in stratifying high-risk patients in large registries. Reconstructing the traditional 12-lead electrocardiogram into QRS vector magnitude can be used to quantify depolarization dispersion and identify high-risk BrS patients. The aim of the study is to test the significance of the QRSvm as a predictor for VTA in patients with BrS. In this retrospective cohort, we included 136 patients (47 ± 15 years, 66% male) who visited outpatient clinic for cardiogenetic screening. All medical records were examined, all 12- lead electrocardiograms were reconstructed into QRSvm using Kors' quasiorthogonal method and were assessed for the presence of electrocardiographic signs indicative of RVOT conduction delay including R wave sign, deep SI, SII >SIII pattern, and Tzou criteria. QRSvm was significantly lower in patients who either presented with VTA or developed VTA during follow-up (1.24 ± 0.35 vs 1.78 ± 0.42 mV, p < 0.001). Positive RVOT conduction delay signs occurred more frequently in symptomatic patients (20% vs 7%, p < 0.001).The area under receiver operator characteristic curve for QRSvm was 0.85 (95% confidence interval [CI] 0.77 to 0.92). Using QRSvm cutoff of 1.55 mV, sensitivity and specificity were 89% and 71%, respectively. Multivariate regression analysis showed that QRSvm and RVOT signs are independent predictors for VTA in BrS patients (QRS vector magnitude: odds ratio 3.68, 95% CI 2.4 to 6.2, p = 0.001; RVOT: odds ratio 2.6, 95% CI 1.4 to 4.9, p = 0.001). In conclusion, not only electrocardiographic signs indicative of RVOT conduction delay but also QRSvm can be used as a predictor for VTA events in BrS patients.
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Síndrome de Brugada/fisiopatología , Sistema de Conducción Cardíaco/fisiopatología , Taquicardia Ventricular/diagnóstico , Taquicardia Ventricular/fisiopatología , Adulto , Síndrome de Brugada/complicaciones , Electrocardiografía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Sensibilidad y Especificidad , Taquicardia Ventricular/etiologíaRESUMEN
BACKGROUND: Areas of conduction delay (CD) or conduction block (CB) are associated with higher recurrence rates after ablation therapy for atrial fibrillation (AF). OBJECTIVE: Thus far, there are no reports on the quantification of the extensiveness of CD and CB at the pulmonary vein area (PVA) and their clinical relevance. METHODS: Intraoperative high-density epicardial mapping of the PVA (interelectrode distance 2 mm) was performed during sinus rhythm in 268 patients (mean ± SD [minimum-maximum] 67 ± 11 [21-84] years) with and without preoperative AF. For each patient, extensiveness of CD (conduction velocity 17-29 cm/s) and CB (conduction velocity <17 cm/s) was assessed and related to the presence and type of AF. RESULTS: CD and CB occurred in, respectively, 242 (90%) and 183 (68%) patients. Patients with AF showed a higher incidence of continuous conduction delay and block (CDCB) lines (AF: n = 37 [76%]; no AF: n = 132 [60%]; P = .046), a 2-fold number of lines per patient (CD: 7 [0-30] vs 4 [0-22], P < .001; CB: 3 [0-11] vs 1 [0-12], P = .003; CDCB: 2 [0-6] vs 1 [0-8], P = .004), and a higher incidence of CD or CB lines ≥6 mm and CDCB lines ≥16 mm (P = .011, P = .025, and P = .027). The extensiveness of CD, CB, and CDCB could not distinguish between the different AF types. CONCLUSION: Patients with AF more often present with continuous lines of adjacent areas of CD and CB, whereas in patients without AF, lines of CD and CB are shorter and more often separated by areas with normal intra-atrial conduction. However, a considerable overlap in the amount of conduction abnormalities at the PVA was observed between patients with a history of paroxysmal and persistent AF.
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Fibrilación Atrial/fisiopatología , Fibrilación Atrial/cirugía , Ablación por Catéter , Sistema de Conducción Cardíaco/fisiopatología , Venas Pulmonares/fisiopatología , Venas Pulmonares/cirugía , Adulto , Anciano , Anciano de 80 o más Años , Trastorno del Sistema de Conducción Cardíaco/fisiopatología , Trastorno del Sistema de Conducción Cardíaco/cirugía , Mapeo Epicárdico , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
Mapping of the unorganized activation patterns of atrial fibrillation requires a high-resolution mapping approach to diagnose substrate-mediated pathophysiological mechanisms. At present, epicardial mapping is the only approach that is able to acquire electrograms of >200 high-density sites simultaneously. This study introduces a technique to perform high-resolution mapping in minimally invasive surgery. In 3 patients with mitral valve disease, epicardial mapping of the right atrium, Bachmann's bundle and parts of the left atrium was safely performed via minimal right thoracotomy.
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Fibrilación Atrial/cirugía , Procedimientos Quirúrgicos Cardíacos , Mapeo Epicárdico/métodos , Sistema de Conducción Cardíaco/fisiopatología , Enfermedades de las Válvulas Cardíacas/cirugía , Procedimientos Quirúrgicos Mínimamente Invasivos/métodos , Válvula Mitral/cirugía , Anciano , Fibrilación Atrial/fisiopatología , Femenino , Atrios Cardíacos/fisiopatología , Enfermedades de las Válvulas Cardíacas/fisiopatología , Humanos , Periodo Intraoperatorio , Masculino , Persona de Mediana EdadRESUMEN
AIMS: Targeting of complex fractionated electrograms (CFEs) in the atria is not yet beneficial in treating drug-refractory atrial fibrillation (AF). In order to gain insight into potential anatomical hotspots of fractionated electrograms, a structured literature search was performed. METHODS AND RESULTS: PubMed was searched for studies describing fractionation during human atrial electrophysiological measurements (n = 565), of which 36 articles described the pre-ablation distribution of fractionated electrograms for the left atrium and/or right atrium in at least four regions. Fractionation was commonly found in high proportions within all regions of both atria, without clear preference for specific regions. Furthermore, no differences in the fractionation distribution between paroxysmal AF and persistent AF patients were observed. CONCLUSION: Whereas atrial inhomogeneous conduction is widely believed to play a key role in AF initiation and perpetuation, different electrophysiological causes for fractionation and the influence of measurement properties complicate identification of the arrhythmogenic substrate. Thereby, simply targeting all CFEs would be short-sighted. Further research is warranted on how to distinguish 'physiologic CFEs' from 'pathologic CFEs', with only the latter reflecting potential targets for ablative therapy of AF.
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Potenciales de Acción , Fibrilación Atrial/diagnóstico , Función del Atrio Izquierdo , Función del Atrio Derecho , Técnicas Electrofisiológicas Cardíacas , Atrios Cardíacos/fisiopatología , Frecuencia Cardíaca , Fibrilación Atrial/fisiopatología , Fibrilación Atrial/cirugía , Ablación por Catéter , Atrios Cardíacos/cirugía , Humanos , Valor Predictivo de las PruebasRESUMEN
BACKGROUND: Extensiveness of conduction delay and block at the pulmonary vein area (PVA) was quantified in a previous study. We hypothesized that the combination of lines of conduction block with multiple concomitantly entering sinus rhythm wavefronts at the PVA may result in increased arrhythmogenicity and susceptibility to atrial fibrillation (AF). METHODS: Intraoperative high-density epicardial mapping of PVA (N≈450 sites, interelectrode distances: 2 mm) was performed during sinus rhythm in 327 patients (241 male [74%], 67±10 [21-84] years) with and without preoperative AF. For each patient, activation patterns at the PVA were quantified, including the location of entry sites of wavefronts, direction of propagation, and their relative activation times. The association between activation patterns and the presence of AF was examined. RESULTS: Excitation of the PVA occurred via multiple consecutive wavefronts in the vast majority of patient (N=216, 81%). In total, 561 wavefronts were observed, which mostly propagated through the septal or paraseptal regions towards the PVA (N=461, 82%). A substantial dissociation of consecutive wavefronts was observed with Δactivation times of 10.6±8.8 (0-46) ms. No difference was observed in Δactivation times of consecutive wavefronts during sinus rhythm between patients without and with AF. An excitation-based risk factor model, including conduction delay ≥6 mm, conduction block ≥6 mm, and conduction delay and block ≥16 mm, wavefronts via the posteroinferior to posterosuperior regions and multiple opposing wavefronts, demonstrated a 5-fold risk of AF when multiple risk factors were present. CONCLUSIONS: In contrast to previous findings, quantification of activation patterns at the PVA on high-resolution scale demonstrated complex patterns with often multiple entry sites and high interindividual variability. Altered patterns of activation, consisting of multiple opposing wavefronts combined with long lines of conduction slowing, were associated with the presence of AF.
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Fibrilación Atrial/etiología , Fibrilación Atrial/fisiopatología , Mapeo Epicárdico/métodos , Bloqueo Cardíaco/fisiopatología , Sistema de Conducción Cardíaco/fisiopatología , Venas Pulmonares/fisiopatología , Adulto , Anciano , Anciano de 80 o más Años , Procedimientos Quirúrgicos Cardíacos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Factores de RiesgoRESUMEN
BACKGROUND: Brugada syndrome (BrS) is an autosomal dominant disease responsible for sudden cardiac death in young individuals without structural anomalies. The most critical part in the management of this channelopathy is identification of high-risk patients, especially asymptomatic subjects. Prior studies have shown that conduction delay in the right ventricular outflow tract (RVOT) is the main mechanism for developing ventricular tachyarrhythmia (VTA) in BrS patients. The aim of this study was to investigate the significance of electrocardiographic RVOT conduction delay parameters as predictors for development of VTA in patients with BrS. METHODS AND RESULTS: We retrospectively analyzed electrocardiograms obtained from 147 BrS patients (43 ± 15 years, 65% men) and assessed the following electrocardiographic parameters: (1) Tzou criteria (V1R > 0.15 mV, V6S > 0.15 mV, and V6S:R > 0.2), (2) prominent S wave in lead I, lead II, and lead III, (3) SII > SIII, and (4) prominent Q wave in lead III as possible predictors of VTA occurrences during follow-up. Prominent SI, SII, SIII, SII > SIII, QIII, and +ve Tzou criteria occurred more frequently in patients who either presented with VTA or developed VTA during the follow-up of 56 (IQR: 40-76) months. SII > SIII has the highest area under the curve for prediction of VTA (AUC: 0.84, sensitivity: 80%, specificity: 89%). Multivariable regression analysis showed that prominent S waves in lead I, SII > SIII and +ve Tzou criteria are independent predictors for VTA in BrS patients. CONCLUSION: Prominent S in lead I, SII > SIII and +ve Tzou criteria can be used as effective signs for predicting VTA in patients with BrS.
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Síndrome de Brugada/diagnóstico , Síndrome de Brugada/fisiopatología , Taquicardia Ventricular/diagnóstico , Taquicardia Ventricular/fisiopatología , Obstrucción del Flujo Ventricular Externo/diagnóstico , Obstrucción del Flujo Ventricular Externo/fisiopatología , Adulto , Síndrome de Brugada/epidemiología , Electrocardiografía/tendencias , Femenino , Estudios de Seguimiento , Sistema de Conducción Cardíaco/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Estudios Retrospectivos , Taquicardia Ventricular/epidemiología , Obstrucción del Flujo Ventricular Externo/epidemiologíaRESUMEN
BACKGROUND: The influence of underlying heart disease or presence of atrial fibrillation (AF) on atrial excitation during sinus rhythm (SR) is unknown. We investigated atrial activation patterns and total activation times of the entire atrial epicardial surface during SR in patients with ischemic and/or valvular heart disease with or without AF. METHODS AND RESULTS: Intraoperative epicardial mapping (N=128/192 electrodes, interelectrode distances: 2 mm) of the right atrium, Bachmann's bundle (BB), left atrioventricular groove, and pulmonary vein area was performed during SR in 253 patients (186 male [74%], age 66±11 years) with ischemic heart disease (N=132, 52%) or ischemic valvular heart disease (N=121, 48%). As expected, SR origin was located at the superior intercaval region of the right atrium in 232 patients (92%). BB activation occurred via 1 wavefront from right-to-left (N=163, 64%), from the central part (N=18, 7%), or via multiple wavefronts (N=72, 28%). Left atrioventricular groove activation occurred via (1) BB: N=108, 43%; (2) pulmonary vein area: N=9, 3%; or (3) BB and pulmonary vein area: N=136, 54%; depending on which route had the shortest interatrial conduction time (P<0.001). Ischemic valvular heart disease patients more often had central BB activation and left atrioventricular groove activation via pulmonary vein area compared with ischemic heart disease patients (N=16 [13%] versus N=2 [2%]; P=0.009 and N=86 [71%] versus N=59 [45%]; P<0.001, respectively). Total activation times were longer in patients with AF (AF: 136±20 [92-186] ms; no AF: 114±17 [74-156] ms; P<0.001), because of prolongation of right atrium (P=0.018) and BB conduction times (P<0.001). CONCLUSIONS: Atrial excitation during SR is affected by underlying heart disease and AF, resulting in alternative routes for BB and left atrioventricular groove activation and prolongation of total activation times. Knowledge of atrial excitation patterns during SR and its electropathological variations, as demonstrated in this study, is essential to further unravel the pathogenesis of AF.
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Potenciales de Acción , Fibrilación Atrial/etiología , Técnicas Electrofisiológicas Cardíacas , Atrios Cardíacos/fisiopatología , Sistema de Conducción Cardíaco/fisiopatología , Enfermedades de las Válvulas Cardíacas/complicaciones , Isquemia Miocárdica/complicaciones , Pericardio/fisiopatología , Adulto , Anciano , Anciano de 80 o más Años , Fibrilación Atrial/diagnóstico , Fibrilación Atrial/fisiopatología , Electrocardiografía , Femenino , Frecuencia Cardíaca , Enfermedades de las Válvulas Cardíacas/diagnóstico , Enfermedades de las Válvulas Cardíacas/cirugía , Humanos , Cinética , Masculino , Persona de Mediana Edad , Isquemia Miocárdica/diagnóstico , Isquemia Miocárdica/cirugía , Valor Predictivo de las Pruebas , Adulto JovenRESUMEN
BACKGROUND: Early postoperative atrial fibrillation (EPoAF) is associated with thromboembolic events, prolonged hospitalization, and development of late PoAF (LPoAF). It is, however, unknown if EPoAF can be predicted by intraoperative AF inducibility. The aims of this study are therefore to explore (1) the value of intraoperative inducibility of AF for development of both EPoAF and LPoAF and (2) the predictive value of de novo EPoAF for recurrence of LPoAF. METHODS AND RESULTS: Patients (N=496, 75% male) undergoing cardiothoracic surgery for coronary and/or valvular heart disease were included. AF induction was attempted by atrial pacing, before extracorporeal circulation. All patients were on continuous rhythm monitoring until discharge to detect EPoAF. During a follow-up period of 2 years, LPoAF was detected by ECGs and Holter recordings. Sustained AF was inducible in 56% of patients. There was no difference in patients with or without AF before surgery (P=0.159), or between different types of surgery (P=0.687). In patients without a history of AF, incidence of EPoAF and LPoAF was 37% and 2%, respectively. EPoAF recurred in 58% patients with preoperative AF, 53% developed LPoAF. There were no correlations between intraoperative inducibility and EPoAF or LPoAF (P>0.05). EPoAF was not correlated with LPoAF in patients without a history of AF (P=0.116), in contrast to patients with AF before surgery (P<0.001). CONCLUSIONS: Intraoperative AF inducibility does not predict development of either EPoAF or LPoAF. In patients with AF before surgery, EPoAF is correlated with LPoAF recurrences. This correlation is absent in patients without AF before surgery.
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Fibrilación Atrial/epidemiología , Estimulación Cardíaca Artificial , Procedimientos Quirúrgicos Cardíacos/efectos adversos , Técnicas Electrofisiológicas Cardíacas , Monitoreo Intraoperatorio/métodos , Potenciales de Acción , Anciano , Anciano de 80 o más Años , Fibrilación Atrial/diagnóstico , Fibrilación Atrial/fisiopatología , Femenino , Frecuencia Cardíaca , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Países Bajos/epidemiología , Recurrencia , Medición de Riesgo , Factores de Riesgo , Factores de Tiempo , Resultado del TratamientoRESUMEN
BACKGROUND: Endo-epicardial asynchrony (EEA) and the interplay between the endocardial and epicardial layers could be important in the pathophysiology of atrial arrhythmias. The morphologic differences between epicardial and endocardial atrial electrograms have not yet been described, and electrogram morphology may hold information about the presence of EEA. OBJECTIVE: The purpose of this study was to directly compare epicardial to endocardial unipolar electrogram morphology during sinus rhythm (SR) and to evaluate whether EEA contributes to electrogram fractionation by correlating fractionation to spatial activation patterns. METHODS: In 26 patients undergoing cardiac surgery, unipolar electrograms were simultaneously recorded from the epicardium and endocardium at the inferior, middle, and superior right atrial (RA) free wall during SR. Potentials were analyzed for epi-endocardial differences in local activation time, voltage, RS ratio, and fractionation. The surrounding and opposite electrograms of fractionated deflections were evaluated for corresponding local activation times in order to determine whether fractionation originated from EEA. RESULTS: The superior RA was predisposed to delayed activation, EEA, and fractionation. Both epicardial and endocardial electrograms demonstrated an S-predominance. Fractionation was mostly similar between the 2 sides; however, incidentally deflections up to 4 mV on 1 side could be absent on the other side. Remote activation was responsible for most fractionated deflections (95%) in SR, of which 4% could be attributed to EEA. CONCLUSION: Local epi-endocardial differences in electrogram fractionation occur occasionally during SR but will likely increase during arrhythmias due to increasing EEA and (functional) conduction disorders. Electrogram fractionation can originate from EEA, and this study demonstrated that unipolar electrogram fractionation can potentially identify EEA.
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Arritmias Cardíacas/fisiopatología , Mapeo del Potencial de Superficie Corporal/métodos , Atrios Cardíacos/fisiopatología , Sistema de Conducción Cardíaco/fisiopatología , Anciano , Endocardio/fisiopatología , Femenino , Humanos , Masculino , Reproducibilidad de los ResultadosRESUMEN
BACKGROUND: Atrial extrasystoles (AES) can initiate atrial fibrillation. However, the impact of spontaneous AES on intra-atrial conduction is unknown. The aims of this study were to examine conduction disorders provoked by AES and to correlate these conduction differences with patient characteristics, mapping locations, and type of AES. METHODS AND RESULTS: High-resolution epicardial mapping (electrodes N=128 or N=192; interelectrode distance, 2 mm) of the entire atrial surface was performed in patients (N=164; 69.5% male; age 67.2±10.5 years) undergoing open-chest cardiac surgery. AES were classified as premature, aberrant, or prematurely aberrant. Conduction delay and conduction block were quantified during sinus rhythm and AES and subsequently compared. Median incidence of conduction delay and conduction block during sinus rhythm was 1.2% (interquartile, 0%-2.3%) and 0.4% (interquartile, 0%-2.1%). In comparison, the median incidence of conduction delay and conduction block during 339 AES was respectively 2.8% (interquartile, 1.3%-4.6%) and 2.2% (interquartile, 0.3%-5.1%) and differed between the types of AES (prematurely aberrant>aberrant>premature). The degree of prematurity was not associated with a higher incidence of conduction disorders (P>0.05). In contrast, a higher degree of aberrancy was associated with a higher incidence of conduction disorders; AES emerging as epicardial breakthrough provoked most conduction disorders (P≥0.002). AES caused most conduction disorders in patients with diabetes mellitus and left atrial dilatation (P<0.05). CONCLUSIONS: Intraoperative high-resolution epicardial mapping showed that conduction disorders are mainly provoked by prematurely aberrant AES, particularly in patients with left atrial dilation and diabetes mellitus or emerging as epicardial breakthrough.
Asunto(s)
Complejos Atriales Prematuros/diagnóstico , Procedimientos Quirúrgicos Cardíacos , Mapeo Epicárdico/métodos , Atrios Cardíacos/fisiopatología , Sistema de Conducción Cardíaco/fisiopatología , Frecuencia Cardíaca/fisiología , Monitoreo Intraoperatorio/métodos , Anciano , Complejos Atriales Prematuros/fisiopatología , Femenino , Estudios de Seguimiento , Cardiopatías/cirugía , Humanos , MasculinoRESUMEN
BACKGROUND: Length of lines of conduction block (CB) during sinus rhythm (SR) at Bachmann's bundle (BB) is associated with atrial fibrillation (AF). However, it is unknown whether extensiveness of CB at BB represents CB elsewhere in the atria. We aim to investigate during SR 1) the spatial distribution and extensiveness of CB 2) whether there is a predilection site for CB and 3) the association between CB and incidence of post-operative AF. METHODS: During SR, epicardial mapping of the right atrium (RA), BB and left atrium was performed in 209 patients with coronary artery disease. The amount of conduction delay (CD, Δlocal activation time ≥7ms) and CB (Δ≥12ms) was quantified as % of the mapping area. Atrial regions were compared to identify potential predilection sites for CD/CB. Correlations between CD/CB and clinical characteristics were tested. RESULTS: Areas with CD or CB were present in all patients, overall prevalence was respectively 1.4(0.2-4.0) % and 1.3(0.1-4.3) %. Extensiveness and spatial distribution of CD/CB varied considerably, however occurred mainly at the superior intercaval RA. Of all clinicalcharacteristics, CD/CB only correlated weakly with age and diabetes (P<0.05). A 1% increase in CD or CB caused a 1.1-1.5ms prolongation of the activation time (P<0.001). There was no correlation between CD/CB and post-operative AF. CONCLUSION: CD/CB during SR in CABG patients with electrically non-remodeled atria show considerable intra-atrial, but also inter-individual variation. Despite these differences, a predilection site is present at the superior intercaval RA. Extensiveness of CB at the superior intercaval RA or BB does not reflect CB elsewhere in the atria and is not associated with post-operative AF.
Asunto(s)
Trastorno del Sistema de Conducción Cardíaco/diagnóstico , Trastorno del Sistema de Conducción Cardíaco/fisiopatología , Mapeo Epicárdico/métodos , Sistema de Conducción Cardíaco/fisiopatología , Frecuencia Cardíaca/fisiología , Anciano , Trastorno del Sistema de Conducción Cardíaco/cirugía , Femenino , Bloqueo Cardíaco/diagnóstico , Bloqueo Cardíaco/fisiopatología , Bloqueo Cardíaco/cirugía , Humanos , Masculino , Persona de Mediana EdadRESUMEN
BACKGROUND: Epicardial breakthrough waves (EBW) during atrial fibrillation are important elements of the arrhythmogenic substrate and result from endo-epicardial asynchrony, which also occurs to some degree during sinus rhythm (SR). We examined the incidence and characteristics of EBW during SR and its possible value in the detection of the arrhythmogenic substrate associated with atrial fibrillation. METHODS AND RESULTS: Intraoperative epicardial mapping (interelectrode distances 2 mm) of the right atrium, Bachmann's bundle, the left atrioventricular groove, and the pulmonary vein area was performed during SR in 381 patients (289 male, 67±10 years) with ischemic or valvular heart disease. EBW were referred to as sinus node breakthrough waves if they were the earliest right atrial activated site. A total of 218 EBW and 57 sinus node breakthrough waves were observed in 168 patients (44%). EBW mostly occurred at right atrium (N=105, 48%) and left atrioventricular groove (N=67, 31%), followed by Bachmann's bundle (N=27, 12%) and pulmonary vein area (N=19, 9%; P<0.001). EBW occurred most often in ischemic heart disease patients (N=114, 49%) compared with (ischemic and) valvular heart disease patients (N=26, 17%; P<0.001). EBW electrograms most often consisted of double and fractionated potentials (N=137, 63%). In case of single potentials, an R wave was observed in 88% (N=71) of EBW, as opposed to 21% of sinus node breakthrough waves (N=5; P<0.001). Fractionated EBW potentials were more often observed at the right atrium and Bachmann's bundle (P<0.001). CONCLUSIONS: During SR, EBW are present in over a third of patients, particularly in thicker parts of the atrial wall. Features of SR EBW indicate that muscular connections between endo- and epicardium underlie EBW and that a slight degree of endo-epicardial asynchrony required for EBW to occur is already present in some areas during SR. Hence, an anatomic substrate is present, which may enhance the occurrence of EBW during atrial fibrillation, thereby promoting atrial fibrillation persistence.
Asunto(s)
Fibrilación Atrial/fisiopatología , Mapeo Epicárdico , Atrios Cardíacos/fisiopatología , Pericardio/fisiopatología , Adulto , Anciano , Anciano de 80 o más Años , Electrocardiografía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Venas Pulmonares/fisiopatologíaRESUMEN
Supraventricular tachyarrhythmia (SVT), especially atrial fibrillation (AF), has been observed in patients with inherited cardiac arrhythmia (ICA). Data on the time course of SVT and the occurrence of SVT other than AF is limited. In this study, we examined the prevalence, co-existence, and the time course of different types of SVT in patients with various ICAs. In this retrospective study, we selected 393 patients (median 49 years, range 17 to 87, 57% male) from a cohort of patients visiting the outpatient clinic for cardiogenetic screening of ICA. Patients' medical records were examined for the occurrence of AF and other SVT. AF/SVT was found in 49 patients (12%, 31 male, 42 ± 17 years). Patients presenting with only AF (n = 12, 3%) were older than patients presenting with only SVT (n = 28, 7%), respectively 52 ± 18 versus 37 ± 14, p = 0.007. Nineteen patients (5%) had multiple episodes of either AF (n = 7, 2%) or SVT (n = 12, 3%). Alternating episodes of AF and SVT occurred in 9 patients (2%). Intervals between second and third AF episodes were significantly shorter than between first and second episodes (p = 0.02). An implantable cardioverter defibrillator (ICD) was implanted in 158 patients (40.2%) and 26 patients (16%) had inappropriate ICD shocks (SVT 25, AF 1), particularly those with multiple SVT episodes (p = 0.003). In patients with a variety of ICAs, episodes of AF/SVT occurred in 12%. In patients with multiple AF episodes, intervals between consecutive episodes became significantly shorter over time. AF/SVT episodes are associated with inappropriate ICD shocks and aggressive therapy of AF/SVT is therefore justified.