P Wave Indices

Abstract

O ur review describes the current field of P wave indices. We report the methodology for determining P wave indices. We also describe the strengths and limitations of the current literature on the clinical correlates and prognosis of P wave indices. We suggest future clinical and research directions for P wave indices.The P wave indices of maximum duration and dispersion have received increasing attention and have been examined in a broad range of clinical settings. The ECG, as a vectorcardiogram, 1 quantifies the magnitude and direction of electric propagation and depolarization. Insults such as chronically elevated atrial pressure, ischemia, and metabolic stress lead to atrial remodeling marked by inflammation, fibrosis and poor cellular coupling. The electrophysiological result is slowed conduction with inhomogeneous recovery, defining a substrate for atrial fibrillation (AF). 2 Investigators hypothesize that P wave prolongation is an intermediate step in the accumulation of insults ultimately leading to AF. Thus, initial studies sought to demonstrate significant differences between samples with a history of AF and healthy referents, arguing that prolonged P wave duration and dispersion predict recurrent AF. Further studies have used P wave indices to compare multiple samples with and without cardiac diseases. The most recent iteration of studies has extended use of P wave indices beyond cardiac pathology to distinguish a variety of disease entities and comparison groups; the wide array of disease samples studied is listed in Table 1. Given such broad clinical applications, automated reporting of the P wave duration in electrocardiographic measurement for screening purposes has been advocated. 41 The variety of studies has resulted in varying methodologies and yielded conflicting results. Many areas in P wave indices research remain uncertain, including their clinical correlates and distribution in the community, and the extent to which P wave indices are associated with AF, predict its occurrence, are heritable phenotypes, or serve as biomarkers of other cardiovascular insults. The present review was undertaken to assess the current evidence for use of P wave indices with attention toward study design, strengths, and remaining questions surrounding their clinical application. Literature Search MethodsWe conducted a literature search of PubMed and OVID databases to identify articles published from January 1985 to December 2007. We searched using the Medical Subject Headings and key words of P wave dispersion, P wave indices, dispersion, AF, and ECG, both separately and together with predict and prediction. We reviewed reference lists of retrieved articles to identify additional publications for inclusion. Because of the volume of research in this area and the duplicative nature of the field's research, we excluded studies with less than 100 subjects unless they described a novel clinical application of P wave indices. Studies were described as cohort, case control, or cross-sectional. Case reports, scientific...

Effects of Obstructive Sleep Apnea and its Treatment on Signal-Averaged P-Wave Duration in Men

“…10 Indeed, several studies including ours have shown a relationship between the presence or severity of OSA and the P-wave prolongation on a standard 12-lead ECG. 11 However, compared with P-wave duration on a standard 12-lead ECG, P-wave duration that is assessed with a signal-averaged ECG (signal-averaged P-wave duration [SAPWD]) has been established as a more reliable and accurate index of global atrial conduction.…”

The Physionet QT Database: Study on the Reliability of P-wave Manual Annotations under Noisy Recordings

“…Moreover, the presence of noise in the signal may further complicate this task, especially for low amplitude waves such as the Pwave. Due to this evidence, and the increasing attention that has gained the delineation of P-waves within the ECG because of the demonstrated relationship between different morphological characteristics of this waveform and clinical conditions, such as the recurrence of atrial fibrillation [6], the P-wave in particular has been selected in this study to evaluate the accuracy or the QTDB manual annotations.…”

Electrical atrial vulnerability and renal complications in type 2 diabetes

“…The mechanisms underlying this association remain largely unknown. Interestingly, prolonged P-wave duration on the ECG, considered to be an intermediate indicator of the accumulation of insults that ultimately leads to AF, has also been reported to be increased in patients with diabetes, even in those without ischaemia, hypertension or left ventricular hypertrophy [3].…”