Atrial fibrillation in end stage renal disease patients: influence of hemodialysis on P wave duration and atrial dimension

Depolarization of the Atrial Subepicardium in Rats with Experimentally Induced Pulmonary Hypertension

Using an experimental model of pulmonary hypertension in rats (monocrotaline in a dose of 60 mg/kg), we revealed an additional focus of early excitation in the zone where the pulmonary veins enter the left atrium, in addition to the main focus in the sinoatrial node. Pulmonary hypertension leads to the formation of regions of early activation in the right and left atria and a significant change in the sequence of atrial depolarization. Propagation of independent excitation waves in the right and left atria increases heterogeneity of depolarization and leads to the formation of atrial arrhythmias.

Prevalence and associated factors of undiagnosed atrial fibrillation among end-stage renal disease patients on maintenance haemodialysis: a cross-sectional study

BACKGROUND

Atrial fibrillation (AF) is the most prevalent sustained arrhythmia worldwide and it aggravates cardiovascular morbidity and mortality; however, this is largely under-diagnosed. Moreover, among end-stage renal disease patients on haemodialysis, AF is substantially more common and serious. The researchers conducted this study to assess the prevalence of, and the factors correlated with AF in Jordanian haemodialysis patients.

METHODS

In a cross-sectional analysis conducted from October 2018 to February 2019 in four tertiary hospitals, the researchers enrolled all consenting patients aged 18 years or older who were on haemodialysis for at least three months prior to the study. We screened for AF clinically by pulse palpation, precordial auscultation, by an automated blood pressure monitor and an electrocardiogram. The researchers reported qualitative variables as counts and frequencies, while continuous variables were summarised using the mean or median where necessary. We used multiple logistic regression with backward selection to identify independent risk factors of AF.

RESULTS

A total of 231 patients were enrolled; mean age was 54.8 ± 15.6 years (from 20 to 86), and 44.3% of them were women. The prevalence of AF was found to be 7.8% (95% CI, 4.8-12.2), with no gender disparity. Age (adjusted odds ratio [AOR] = 1.05; 95% CI, 1.01-1.10; p = 0.031), history of ischaemic heart disease (AOR = 3.74; 95% CI, 1.09-12.34; p = 0.033), history of smoking (AOR = 0.15; 95% CI, 0.02-0.60; p = 0.019), and low interdialytic weight gain (AOR = 0.50: 95% CI, 0.25-0.91; p = 0.031) were independently correlated to AF.

CONCLUSIONS

The prevalence of AF among patients on maintenance haemodialysis is high, but largely undiagnosed. AF is generally associated with advancing age, history of ischaemic heart disease, lower interdialytic weight gain, and history of smoking. We suggest routine check-up of AF in this high-risk group of patients as anticoagulant therapy if indicated may prevent serious complications. However, there is a need for large-scale cohort studies and for the creation of regional chronic kidney disease and dialysis registries in the Middle East region.

Blood Pressure and Incident Atrial Fibrillation in Older Patients Initiating Hemodialysis

BACKGROUND AND OBJECTIVES

We examined the association of predialysis systolic and diastolic BP and intradialytic hypotension with incident atrial fibrillation in older patients initiating hemodialysis.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We used the US Renal Data System linked to the records of a large dialysis provider to identify patients aged ≥67 years initiating hemodialysis between January 2006 and October 2011. We examined quarterly average predialysis systolic BP, diastolic BP, and proportion of sessions with intradialytic hypotension (i.e., nadir systolic BP <90 mm Hg). We applied an extended Cox model to compute adjusted hazard ratios (HRs) of each exposure with incident atrial fibrillation.

RESULTS

Among 17,003 patients, 3785 developed atrial fibrillation. When comparing predialysis systolic BP to a fixed reference of 140 mm Hg, lower predialysis systolic BP was associated with a higher hazard of atrial fibrillation, whereas higher systolic BP was associated with a lower hazard of atrial fibrillation. When comparing across a range of systolic BP for two hypothetical patients with similar measured covariates, the association varied by mean systolic BP: at systolic BP 190 mm Hg, each 10 mm Hg lower systolic BP was associated with lower atrial fibrillation hazard (HR, 0.94; 95% confidence interval, 0.90 to 1.00), whereas at systolic BP 140 mm Hg, a 10 mm Hg lower systolic BP was associated with a higher atrial fibrillation hazard (HR, 1.12; 95% confidence interval, 1.10 to 1.14). Lower diastolic BP was associated with higher atrial fibrillation hazards. Intradialytic hypotension was weakly associated with atrial fibrillation.

CONCLUSIONS

In this observational study of older patients initiating hemodialysis, lower predialysis systolic BP and diastolic BP were associated with higher incidence of atrial fibrillation.

Factors influencing P terminal force in lead V1 of the ECG in hemodialysis patients

INTRODUCTION

Atrial fibrillation (AF) is a highly prevalent arrhythmia in hemodialysis (HD) patients, and an HD session may be a trigger for AF episodes. An abnormal P-terminal force in lead V1 (PTFV1) may predict new-onset AF in HD patients. The aim of the study was to assess the influence of the HD process on PTFV1 and to evaluate possible factors influencing PTFV1 in a group of selected HD patients.

MATERIAL AND METHODS

One hundred and fifty-three selected HD patients entered the study. Blood chemistry, electrocardiography, and impedance cardiography were evaluated before and after HD. Echocardiography was performed on the morning after dialysis. Abnormal PTFV1 was defined as PTFV1 > 40 mm × ms.

RESULTS

Abnormal PTFV1 was found in 35.3% of patients before dialysis and in 48.4% of patients after dialysis. The results of multiple regression analysis revealed that the independent predictors of pre-dialysis abnormal PTFV1 were: left atrial volume index (p = 0.002), left ventricular mass index (p = 0.014), and pre-dialysis thoracic fluid content (p = 0.021) values. The independent predictors of HD-induced abnormal PTFV1 values were larger differences between pre-dialysis and post-dialysis values of serum potassium (p < 0.001) and mean arterial pressure (p = 0.008).

CONCLUSIONS

Abnormal PTFV1 is prevalent in HD patients. The HD process adversely affects PTFV1 values. Pre-dialysis abnormal PTFV1 is mainly associated with structural heart abnormalities and hydration status. HD-induced abnormal PTFV1 is associated predominantly with serum potassium changes as well as HD-induced hypotension. Our results suggest possible risk factors for AF; however, their clinical significance needs to be confirmed in follow-up studies.