The effects of a single dialysis session on atrial electromechanical conduction times and functions

Evaluation of Atrial Electromechanical Delay to Predict Atrial Fibrillation in Hemodialysis Patients

Background and objective: Prevalence of atrial fibrillation is higher in hemodialysis patients as compared to the general population. Atrial electromechanical delay is known as a significant predictor of atrial fibrillation. In this study, we aimed to reveal the relationship between atrial electromechanical delay and attacks of atrial fibrillation. Materials and methods: The study included 77 hemodialysis patients over 18 years of age giving written consent to participate in the study. The patients were divided into two groups based on the results of 24-h Holter Electrocardiogram (Holter ECG) as the ones having attacks of atrial fibrillation and the others without any attack of atrial fibrillation. Standard echocardiographic measurements were taken from all patients. Additionally, atrial conduction times were measured by tissue Doppler technique and atrial electromechanical delays were calculated. Results: Intra- and interatrial electromechanical delay were found as significantly lengthened in the group of patients with attacks of atrial fibrillation (p = 0.03 and p < 0.001 respectively). The optimal cut-off time for interatrial electromechanical delay to predict atrial fibrillation was >21 ms with a specificity of 79.3% and a sensitivity of 73.7% (area under the curve 0.820; 95% confidence interval (CI), 0.716⁻0.898). In the multivariate logistic regression model, interatrial electromechanical delay (odds ratio = 1.230; 95% CI, 1.104⁻1.370; p < 0.001) and hypertension (odds ratio = 4.525; 95% CI, 1.042⁻19.651; p = 0.044) were also associated with atrial fibrillation after adjustment for variables found to be statistically significant in univariate analysis and correlated with interatrial electromechanical delay. Conclusions: Interatrial electromechanical delay is independently related with the attacks of atrial fibrillation detected on Holter ECG records in hemodialysis patients.

Atrial electromechanical delay and left atrial mechanical functions in hemodialysis and peritoneal dialysis patients

INTRODUCTION

Left atrium (LA) mechanical functions and atrial electromechanical delay (AEMD) times were considered independent predictors of cardiovascular morbidity in general population. Data are scant about these parameters in end-stage renal disease (ESRD) patients receiving hemodialysis (HD) and peritoneal dialysis (PD). We aimed to evaluate AEMD times and LA mechanical functions and associated risk factors in HD and PD patients.

METHODS

Forty-four healthy individuals, 62 HD and 50 PD patients were enrolled in the study. Echocardiography was performed before midweek dialysis session for HD patients and on admission for PD patients. Data were expressed as mean ± SD. Spearman's test was used to assess linear associations. Predictors of left intra-atrial EMD time and LA active emptying volume (LAaeV) were assessed by regression analysis.

RESULTS

Left intra-atrial-AEMD times were significantly longer in HD patients compared to PD patients. LAaeV was positively correlated with inter-atrial time, left intra-atrial time, systolic and diastolic BP, calcium and neutrophil-to-lymphocyte ratio (NLR) (r 0.22, p 0.016; r 0.28, p 0.002; r 0.34, p < 0.001; r 0.35, p < 0.001; r 0.37, p < 0.001; r 0.46, p < 0.001, respectively) and negatively correlated with serum uric acid (r -0.31, p 0.013) in ESRD patients. We found positive correlations between left intra-atrial time and LAaeV, LAVmax, LAVp and NLR (r 0.28, p 0.002; r 0.27, p 0.003; r 0.27, p 0.003; r 0.22, p 0.03, respectively) and negative correlations with albumin, uric acid and potassium (r -0.24, p 0.008; r -0.19, p 0.04; r -0.26, p 0.037, respectively). Advanced age, decreased serum albumin and increased NLR were found to be independent predictors of LAaeV; however, only NLR was found to be an independent predictor of AEMD time in this population.

CONCLUSIONS

Increased inflammation might be a risk factor of AEMD and LA mechanical dysfunction in ESRD patients.

Arrhythmia and Sudden Death in Hemodialysis Patients: Protocol and Baseline Characteristics of the Monitoring in Dialysis Study

BACKGROUND

Dialysis patients have high rates of cardiovascular morbidity and mortality, but data on arrhythmia burden, arrhythmia type, arrhythmia triggers, and the identity of terminal arrhythmias have historically been limited by an inability to monitor heart rhythm for prolonged periods.

OBJECTIVES

To investigate arrhythmia and its association with sudden death in dialysis-dependent ESRD, describe the potential for implantable devices to advance study of dialysis physiology, review the ethical implications of using implantable devices in clinical studies, and report on the protocol and baseline results of the Monitoring in Dialysis Study (MiD).

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

In this multicenter, interventional-observational, prospective cohort study, we placed implantable loop recorders in patients undergoing long-term hemodialysis. The proportion of patients experiencing clinically significant arrhythmias was the primary endpoint. For 6 months, we captured detailed data on the primary endpoint, symptomatic arrhythmias, other electrocardiographic variables, dialysis prescription, electrolytes, dialysis-related variables, and vital signs. We collected additional electrocardiographic data for up to 1 year.

RESULTS

Overall, 66 patients underwent implantation in sites in the United States and India. Diabetes was present in 63.6% of patients, 12.1% were age ≥70 years, 69.7% were men, and 53.0% were black. Primary and secondary endpoint data are expected in 2016.

CONCLUSIONS

Cardiac arrhythmia is an important contributor to cardiovascular morbidity and mortality in dialysis patients, but available technology has previously limited the ability to estimate its true burden and triggers and to define terminal rhythms in sudden death. Use of implantable technology in observational studies raises complex issues but may greatly expand understanding of dialysis physiology. The use of implantable loop recorders in MiD is among the first examples of such a trial, and the results are expected to provide novel insights into the nature of arrhythmia in hemodialysis patients.

A Case of Atrial Tachycardia Circulating around a Left Atrial Roof Scar with Diabetes Mellitus and Renal Failure on Hemodialysis

Introduction. Little is known about the effects of volume change by hemodialysis (HD) and mechanical stress caused by an anatomical structure being in contact with the left atrium on the progression of atrial remodeling. We experienced a case of atrial tachycardia (AT) in a patient who had left atrial (LA) scarring at the LA roof and a low-voltage area with slow conduction around the LA scar as components of AT circuit. Here, we present the conceivable hypothesis of the LA scar and the low-voltage area formation. Our concept can be useful in developing a strategy for ablation in a patient with chronic renal failure (CRF) on HD. Case Report. A 65-year-old man with CRF on HD was referred for AT ablation. Three-dimensional electroanatomical mapping revealed that the AT conducted around an LA scar in a counterclockwise fashion. There was a slow conduction area at the superior side of the LA scar, where the AT was terminated during the ablation. Computed tomography indicated a close relationship between the LA and the anatomical structures (ascending aorta and pulmonary artery). Conclusion. Volume change by HD and close contact of anatomical structures to the LA can promote atrial remodeling, resulting in AT occurrence.