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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.
Subject(s)
Tachycardia , Electrophysiologic Techniques, Cardiac , Electrocardiography , Accessory Atrioventricular BundleABSTRACT
Prolonged P-wave duration has been observed in diabetes. However, the underlying mechanisms remain unclear. The aim of this study was to elucidate the possible mechanisms. A rat model of type 2 diabetes mellitus (T2DM) was used. P-wave durations were obtained using surface electrocardiography and sizes of the left atrium were determined using echocardiography. Cardiac inward rectifier K+ currents (I(k1)), Na+ currents (I(Na)), and action potentials were recorded from isolated left atrial myocytes using patch clamp techniques. Left atrial tissue specimens were analyzed for total connexin-40 (Cx40) and connexin-43 (Cx43) expression levels on western-blots. Specimens were also analyzed for Cx40 and Cx43 distribution and interstitial fibrosis by immunofluorescent and Masson trichrome staining, respectively. The mean P-wave duration was longer in T2DM rats than in controls; however, the mean left atrial sizes of each group of rats were similar. The densities of I(k1) and I(Na) were unchanged in T2DM rats compared to controls. The action potential duration was longer in T2DM rats, but there was no significant difference in resting membrane potential or action potential amplitude compared to controls. The expression level of Cx40 protein was significantly lower, but Cx43 was unaltered in T2DM rats. However, immunofluorescent labeling of Cx43 showed a significantly enhanced lateralization. Staining showed interstitial fibrosis was greater in T2DM atrial tissue. Prolonged P-wave duration is not dependent on the left atrial size in rats with T2DM. Dysregulation of Cx40 and Cx43 protein expression, as well as fibrosis, might partly account for the prolongation of P-wave duration in T2DM.
Subject(s)
Animals , Male , Rats , Action Potentials , Blotting, Western , Connexin 43/metabolism , Connexins/metabolism , Diabetes Mellitus, Type 2/physiopathology , Disease Models, Animal , Echocardiography , Electrocardiography , Fibrosis/pathology , Heart Atria/diagnostic imaging , In Vitro Techniques , Membrane Potentials , Microscopy, Fluorescence , Patch-Clamp Techniques , Potassium Channels/metabolism , Rats, WistarABSTRACT
Objective To investigate the electrophysiology mechanism of the P wave dispersion (Pd) and the maximum P wave duration (Pmax) in patients with paroxysmal atrial fibrillation (PAF),and evaluate the effect of the Pd and Pmax in the prediction of PAF. Methods Forty-eight patients with PAF (group PAF) were slected and divided into 2 sub-groups according to the organic heart disease,group PAF1 (20 cases, without organic heart disease) and group PAF2 ( 28 cases, with organic heart disease). Forty-six patients without PAF were selected as control group. The Pd and Pmax were measured from the 12-lead surface electrocardiogram (ECG). Results The Pd and Pmax in group PAF was higher than that in control group [(41.11 ± 4.97 ) ms vs. (27.77 ± 4.72) ms, ( 111.43 ± 8.01 ) ms vs. (95.57 ± 9.01 ) ms] (P ＜ 0.05 ). The Pmaxin group PAF2 was significantly higher than that in group PAF1 (P ＜ 0.05),and there was no significant difference in the Pd between group PAF2 and group PAF1 (P＞ 0.05 ). The specificity, sensitivity and positive predictive value of Pd ≥40 ms combined with Pmax ≥ 110 ms was 95.65%, 81.25% and 95.12%. Conclusion The Pd and Pmax in the patients with PAF are significantly higher than those in the patients without PAF, and Pd≥40 ms combined with Pmax≥ 110 ms can be used to predict the PAF more reliably and accurately.
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PURPOSE: A maximum P-wave duration (Pmax) of > or = 110msec and a P-wave dispersion (PWD) > or = 40msec are accepted indicators of a disturbance in interatrial conduction and an inhomogeneous propagation of the sinus impulse, respectively. The left atrial (LA) volume has been reported to be strongly associated with a systolic and diastolic dysfunction and is considered to be an index of atrial remodeling. We aimed to investigate the relationship between LA volume and Pmax or PWD in patients with congestive heart failure (CHF). PATIENTS AND METHODS: Sixty-one patients with CHF were enrolled in this study. The study population was classified into four groups: two groups were divided according to the Pmax (> or = 110msec or or = 40msec or or = 110ms or a PWD > or = 40ms and those with a Pmax < 110ms or a PWD < 40ms. The LAVi was independently associated with a disturbance in interatrial conduction and an inhomogeneous propagation of the sinus impulse. The LAVi can be used to identify patients with a disturbance in interatrial conduction and an inhomogeneous propagation of the sinus impulse with reasonably good accuracy. CONCLUSION: We concluded that a disturbance in interatrial conduction and an inhomogenous propagation of the sinus impulse in patients with CHF is associated with an increase in the LA volume and a deleterious systolic and diastolic dysfunction.
Subject(s)
Aged , Female , Humans , Male , Middle Aged , Atrial Function, Left , Cardiac Volume , Echocardiography , Electrocardiography , Heart Failure/physiopathology , Sinus Arrest, Cardiac/diagnostic imagingABSTRACT
BACKGROUND: P wave dispersion (PWD) and P wave duration have been used to evaluate the discontinuous propagation of sinus impulse and the prolongation of atrial conduction time, respectively. This study was conducted to compare the change of the maximal P wave duration (Pmax) and PWD according to the treatment strategy used in patients with an acute myocardial infarction (AMI). METHODS: We retrospectively evaluated 86 patients that experienced an AMI. Patients were classified into three groups according to the treatment strategy: primary percutaneous coronary intervention (PCI), thrombolytic therapy, and delayed PCI. ECGs that were obtained from all patients on admission and on the second day were analyzed. The Pmax and minimum P wave duration (Pmin) were measured from a 12-lead ECG. The PWD was calculated as the difference between the Pmax and Pmin. RESULT: There was no significant difference in the age, gender, medication, coronary risk factor, ejection fraction, left atrial diameter, basal Pmax and PWD among the groups. However, there were significant differences in P max and PWD between the primary PCI group and the other groups on the second day after hospital admission. In the thrombolytic therapy and delayed PCI groups, the PWD was significantly lower in the patients with a patent infarct-related artery (IRA) than in patients without a patent IRA on the second day after hospital admission. CONCLUSIONS: These findings suggest that a primary PCI decreased the Pmax and PWD more than thrombolytic therapy or a delayed PCI.
Subject(s)
Humans , Arteries , Electrocardiography , Myocardial Infarction , Percutaneous Coronary Intervention , Retrospective Studies , Risk Factors , Thrombolytic TherapyABSTRACT
Objective To assess the prediction value of Pmax and Pd on idiopathic paroxysmal atrial fibrillation(IPAF) and the possible mechanism of amiodrone preventing the recurrence of IPAF.Methods Pmax and Pd were measured in 60 patients with IPAF and 60 healthy control subjects by 12-lead surface electrocardiography. 30 of patients with IPAF were assigned to treatment with amiodrone for 6 months. Pd?Pmax and recurrence of IPAF were observed and compared with control group during the treatment.Results Pmax and Pd were found to be significantly higher in patients with IPAF than in healthy subjects[(126?17)ms vs(102?11)ms; (50?9)vs(29?8)ms,P
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Objective To explore the value of maximun P wave duration (P max ) and P wave dispersion (P d),that is,the difference between the maximum and minimun P wave duration in patients with idiopathic paroxysmal atrial fibrillation.Methods P max and P d were measured from 12 lead surface electrocardiogram among 20 patients with a history of idiopathic paroxysmal atrial fibrillation and 20 age matched healthy control subjects.Results P max and P d were found to be significantly higher in patients with a history of idiopathic paroxysmal atrial fibrillation than in the control subjects(P