P-wave durations as a predictor for atrial fibrillation development in patients with hypertrophic cardiomyopathy

https://doi.org/10.1016/j.ijcard.2003.01.001Get rights and content

Abstract

Atrial fibrillation (AF) is the most common arrhythmia observed in hypertropic cardiomyopathy (HCM) and is associated with an acute deterioration. Recently, P wave dispersion (PWD) reflecting inhomogenous atrial conduction has been proposed as being useful for the estimation of paroxysmal AF. In this study, we aimed to define the clinical, echocardiographic and electrocardiographic predictors for AF occurence in patients with HCM. Twenty-seven patients diagnosed with HCM and having a history of documented AF attack were compared with 53 age- and gender-matched patients who had no such history. LA diameter was significantly greater and gradient in the left ventricle outflow tract was lower in patients with AF than those without AF. Maximum P-wave duration (Pmax), PWD and PTF1 values were significantly higher in patients with AF. A Pmax>134.5 ms separated the patients with AF from controls with a sensitivity of 92%, specificity of 89% and a positive predictive value of 80%. APWD value>52.5 ms separated patients from controls with a sensitivity of 96%, a specificity of 91% and a positive predictive accuracy of 84%. An LA diameter>4.2 cm separated patients from controls with a sensitivity of 96% and a specificity of 81%. We concluded that LA diameter and PWD values are the most significant predictors for AF occurence in patients with HCM, and simply by measuring Pmax and PWD values, we could easily identify the patients with high risk, and prescribe the necessary treatment and follow-up protocols for such patients.

Introduction

Although hypertrophic cardiomyopathy (HCM) was initially thought to be relatively rare, it is now recognized to be an important cause of morbidity and mortality in people of all ages [1]. Atrial fibrillation (AF) is the most common arrhythmia observed in HCM having an incidence ranged between 10% and 40% [2], [3], [4] and is associated with an acute deterioration in symptoms and increased risk of systemic embolization [5], [6].

Prolongation of intratrial and interatrial conduction times and the inhomogeneous propagation of sinus impulses are well-known electrophysiologic characteristics of the atrium prone to fibrillate and have been recently evaluated by two electrocardiographic markers, termed as maximum P-wave duration (Pmax) and P-wave dispersion (PWD) [7]. In this study, we aimed to define the pivotal role of increased Pmax and PWD values as well as some clinical and echocardiographic predictors for AF development in patients with HCM.

Section snippets

Materials and methods

Eighty consecutive patients with HCM examined in our clinics between January 1998 and December 2001 were enrolled in this study and the patients were further classified according to the presence of documented AF attacks lasting more than 30 s. Documentation of AF was based on ECG recordings obtained either after acute onset of symptoms or during routine medical examination in an asymptomatic patient coincidentally. Furthermore, all the patients underwent 24 h holter monitorization to define any

Statistical methods

Continuous variables are expressed as mean±S.D., categorical variables as a percent. For continuous variables Student's t-test, and for categorical variables chi-square (χ2), Fischer's exact and Mann–Whitney U-tests were performed to compare study and control groups. A receiver operating characteristic curve was used to evaluate the various sensitivities and specificities at different cutpoints of Pmax, PWD and LA diameter and relative risk ratios were calculated according to Peto's formula,

Results

Twenty-seven patients with AF compared with a control group consisted of 53 patients without any documented AF attacks. AF was documented in 27 (34%) of patients in this study. There were no significant differences between patients and controls concerning age (P=0.2), gender (P=0.8), LVEFs (P=0.69), the degree of mitral regurgitation (P=0.23), IVS and PW thickness (P=0.72, 0.44, respectively), and their ratio (IVS/PW) (P=0.28), the presence of resting LVOT gradient (P=0.44), and the history of

Discussion

AF is the most common sustained arrhythmia in patients with HCM and it bears numerous pathophsiologic results that potentially affect patient outcome and symptoms [2], [3], [4], [5], [6]. However, studies regarding the impact of AF on long term prognosis of HCM patients have been limited in number, with sometimes conflicting results [2], [10]. Recently, studies on community-based patient populations showed that the development of AF was associated with long term clinical deterioration, embolic

References (20)

There are more references available in the full text version of this article.

Cited by (0)

View full text
Copyright © 2004 Elsevier Ireland Ltd. All rights reserved.