Association of P-wave duration, dispersion, and terminal force in relation to P-wave axis among outpatients

Electrocardiographic and Echocardiographic Predictors of Atrial Fibrillation in Patients With Hypertrophic Cardiomyopathy

Background

Patients with hypertrophic cardiomyopathy (HCM) have an increased prevalence of atrial fibrillation (AF) compared to the general population, and left atrium (LA) remodeling is strongly correlated with the risk of AF. This prospective, monocentric study aimed to assess the role of LA electrocardiographic and echocardiographic (structural and functional) parameters in predicting the risk for incident AF in patients with HCM.

Methods and Results

The study population consisted of 126 HCM patients in sinus rhythm (52.6 ± 16.2 years, 54 men), 118 of them without documented AF. During a median follow-up of 56 (7–124) months, 39 (30.9%) developed a new episode of AF. Multivariable analysis showed that LA booster pump function (assessed by ASr, HR = 4.24, CI = 1.84–9.75, and p = 0.038) and electrical dispersion (assessed by P wave dispersion – Pd, HR = 1.044, CI = 1.029–1.058, and p = 0.001), and not structural parameters (LA diameter, LA volume) were independent predictors of incident AF. Seventy-two patients had a LA diameter < 45 mm, and 16 of them (22.2%) had an AF episode during follow-up. In this subgroup, only Pd emerged as an independent predictor for incident AF (HR = 1.105, CI = 1.059–1.154, and p = 0.002), with good accuracy (AUC = 0.89).

Conclusion

Left atrium booster pump function (ASr) and electrical dispersion (Pd) are related to the risk of incident AF in HCM patients. These parameters can provide further stratification of the risk for AF in this setting, including in patients considered at lower risk for AF based on the conventional assessment of LA size.

A predictive value of the dynamic changes of the P-wave terminal force in lead V1 in the long-term prognosis of patients with non-ST-segment elevation acute coronary syndrome

BACKGROUND

The purpose of this study was to investigate the prognostic value of dynamic changes of P-wave terminal force in lead V1 (PtfV1 ) at electrocardiogram (ECG) in patients with non-ST-segment elevation acute coronary syndrome (NSTE-ACS) during the long-term major adverse cardiovascular events (MACEs) of patients.

METHODS

According to the PtfV1 value, the patients were divided into four groups: PtfV1 (-)/PtfV1 (-), PtfV1 (-)/PtfV1 (+), PtfV1 (+)/PtfV1 (-), and PtfV1 (+)/PtfV1 (+).

RESULTS

The highest incidence of MACEs was the PtfV1 (-)/(+) group with 24 patients (24.7%). The lowest incidence was the PtfV1 (-)/(-) group with 28 patients (4.9%). Compared with the PtfV1 (-)/(-) group, the risk for the occurrence of MACEs in the PtfV1 (-)/(+)group was significantly increased (24.7% vs 4.9%, P = .000). Similarly, the risk in the PtfV1 (+)/(+) group was also increased (10.1% vs 4.9%, P = .000).

CONCLUSION

The persistence of PtfV1 (+) and conversion of PtfV1 /(-) to PtfV1 /(+) at discharge significantly increased the incidence of MACEs.

P-wave dispersion: an update

P-wave dispersion (PWD, Pd or Pdis) is a noninvasive electrocardiographic (ECG) marker for atrial remodeling and predictor for atrial fibrillation (AF). PWD is defined as the difference between the widest and the narrowest P-wave duration recorded from the 12 ECG leads. Increased P-wave duration and PWD reflect prolongation of intraatrial and interatrial conduction time with lack of a well-coordinated conduction system within the atrial muscles, with inhomogeneous, asynchronic, pro-inflammatory and anti-inflammatory effect mediated by interleukin-6 (IL-6) in patients with the CG + GG genotype IL-6 -634C/G polymorphism [1] and discontinuous propagation of sinus impulses mainly between the left and right atria, interstitial/extracellular fibroblast activation and collagen deposition with fibrosis (via TGF-β) in atrial tissue, insufficient blood supply, significant not isotropic myoelectric activity, and thin wall thickness and consequent expansion tendency all well-known electrophysiological characteristics in patients with atrial arrhythmias and especially paroxysmal atrial fibrillation (PAF) [2].

Visual computed tomographic scoring of emphysema and its correlation with its diagnostic electrocardiographic sign: the frontal P vector

BACKGROUND

Verticalization of the frontal P vector in patients older than 45 years is virtually diagnostic of pulmonary emphysema (sensitivity, 96%; specificity, 87%). We investigated the correlation of P vector and the computed tomographic visual score of emphysema (VSE) in patients with established diagnosis of chronic obstructive pulmonary disease/emphysema.

METHODS

High-resolution computed tomographic scans of 26 patients with emphysema (age, >45 years) were reviewed to assess the type and extent of emphysema using the subjective visual scoring. Electrocardiograms were independently reviewed to determine the frontal P vector. The P vector and VSE were compared for statistical correlation. Both P vector and VSE were also directly compared with the forced expiratory volume at 1 second.

RESULTS

The VSE and the orientation of the P vector (ÂP) had an overall significant positive correlation (r = +0.68; P = .0001) in all patients, but the correlation was very strong in patients with predominant lower-lobe emphysema (r = +0.88; P = .0004). Forced expiratory volume at 1 second and ÂP had almost a linear inverse correlation in predominant lower-lobe emphysema (r = -0.92; P < .0001).

CONCLUSION

Orientation of the P vector positively correlates with visually scored emphysema. Both ÂP and VSE are strong reflectors of qualitative lung function in patients with predominant lower-lobe emphysema. A combination of more vertical ÂP and predominant lower-lobe emphysema reflects severe obstructive lung dysfunction.

Electrocardiographic findings in women with a recent history of pre-eclampsia

OBJECTIVE

To assess the prevalence of electrocardiographic (ECG) abnormalities after a pregnancy complicated by pre-eclampsia and/or syndrome of hemolysis, elevated liver enzymes and low platelets (PE) and to compare the ECG characteristics, at least six months after pregnancy, between primiparous early-onset PE women with and without recurrent PE.

DESIGN

Longitudinal observational study.

SETTING

Tertiary referral centre in The Netherlands from 1996 to 2008.

SAMPLE

Six hundred and fifty-eight formerly pre-eclamptic women. For our second objective, we used a subgroup of 79 primiparae with a history of early-onset PE.

METHODS

Data were obtained during a postpartum screening program for women with hypertensive disorders during pregnancy.

MAIN OUTCOME MEASURES

Electrocardiographic abnormalities in PE women and characteristics of the ECG in women with recurrent PE after a first pregnancy complicated by early-onset PE.

RESULTS

The ECG of 13 (2.0%), two (0.3%) and two (0.3%) former patients suggested ischemia, left ventricular hypertrophy and left atrial enlargement, respectively. Primiparae with recurrent PE in their second pregnancy differed from their counterparts with an uneventful second pregnancy by a leftward deviation of both the P- and the R-axes of 11° (p= 0.022) and 12° (p= 0.021), respectively, with a prolonged QT interval (p= 0.025).

CONCLUSIONS

The prevalence of ECG abnormalities in women with a recent history of PE was low and did not differ appreciably from that in a large population of healthy women of comparable age. The ECGs in primiparae with a history of early-onset PE who developed recurrent PE in their second pregnancy differed slightly from women with an uneventful second pregnancy, probably related to potential confounders.