Not the pacing site but the underlying structural heart disease is a reason for wider QRS duration during right ventricular pacing

Background

Right ventricular (RV) pacing causes changes of the electrical and mechanical activation pattern of the heart. QRS duration is reported to be a useful surrogate marker of electrical dyssynchrony, and wider QRS duration during RV pacing indicates poor prognosis. However, the mechanism of widening QRS duration during RV pacing remains to be elucidated.

Methods

A total of 211 patients who underwent catheter ablation for supraventricular tachyarrhythmias and have no bundle-branch-block on ECG were enrolled. During electrophysiological study, 3-dimensional mapping for QRS duration during RV pacing from RV outflow to RV apex was created, and the difference of QRS duration between RV outflow and RV apex was calculated. The relationship between QRS duration during RV pacing and patients' baseline characteristics including echocardiography data was analyzed.

Results

QRS duration at baseline, during RV pacing from RV outflow, and RV apex were 85.0±7.5msec, 156.2±16.1msec, and 163.7±17.1msec, respectively. The difference of QRS duration between RV outflow and RV apex among patients was only 12.5±10.4msec. The logistic multivariable regression analysis showed baseline QRS duration (odds ratio (OR) 1.24, 95% CI 1.15 to 1.34, p<0.01), interventricular septum thickness (OR 1.35, 95% CI 1.05 to 1.73, p=0.018), and E/e' (OR 1.23, 95% CI 1.12 to 1.36, p<0.01) were significant predictors for QRS duration over 160msec during RV apical pacing.

Conclusions

QRS duration during RV pacing depends largely not on the pacing site, but on the underlying structural heart disease.

QRS duration mapping during RV pacing

Funding Acknowledgement

Type of funding source: None

P1032Efficacy and safety of radiofrequency catheter ablation for atrial fibrillation in patients undergoing hemodaialysis

Introduction

Although radiofrequency catheter ablation (RFCA) for atrial fibrillation (AF) has become a standard therapy, the ablation outcomes in patients undergoing hemodialysis (HD) has not been fully elucidated. The present study aimed to evaluate the clinical outcomes of RFCA for AF in patients undergoing HD.

Methods

Twenty-three patients undergoing HD (17 men, age 65±8 years, 19 paroxysmal AF) who underwent RFCA for drug-refractory AF in two institutes were enrolled in the study and defined as HD group. The clinical parameters, recurrence free rate and frequency of periprocedural complications were compared to 46 randomly selected age, gender and left atrial diameter matched controls not requiring HD defined as non-HD group (34men, age 67±7 years, 38 paroxysmal AF).

Results

The patients in HD group had a significantly lower body mass index (21±3 vs. 25±3 P<0.01), higher prevalence of coronary artery disease (30% vs. 10% P=0.04), and higher prevalence of congestive heart failure (52% vs. 10% P<0.01) compared to patients in non-HD group. Echocardiography indicated lower left ventricular ejection fraction (57±17% vs. 65±9% P=0.02), higher E/e' (20±8 vs. 12±4 P<0.01), higher tricuspid regurgitation pressure gradient (30mmHg vs. 24mmHg P<0.01) and more impaired left ventricular diastolic function in HD group. All the subjects underwent bilateral pulmonary vein isolation plus additional linear lesion. The number of ablation procedure was similar between the two groups (1.43±0.5 vs. 1.46±0.6 P=0.88). During the follow-up period of 37±25 months after the last procedure, the arrhythmia free rate was similar between the two groups (86% vs. 84% log-rank P=0.82). Vascular access complication occurred in two patients in HD group, and pericardial effusion occurred in one patient in non-HD group, while no life-threatening complications were observed in either group. Cardiogenic cerebral infarction occurred in one patient in non-HD group. Discontinuation of oral anticoagulation after the ablation was more often seen in the HD group compared to non-HD group (91% vs. 60% P<0.01).

Conclusions

Although patients undergoing HD had more impaired left ventricular systolic and diastolic function, RFCA for AF in patients with HD was shown to be as effective and safe as in non-HD patients. RFCA may be an efficient approach to manage AF in patients undergoing HD.

A cross-cultural study on impaired self-awareness in Japanese patients with brain dysfunction

Japanese patients with brain dysfunction (21 with severe traumatic brain injury [TBI], 21 with right, and 21 with left cerebral vascular accidents [CVA]) were asked to make behavioral ratings regarding their competencies in several areas. Relatives of patients and physical therapists who treated them also rated each patient's behavioral competency. Japanese patients with TBI overestimated their behavioral competencies compared with therapists ratings, but not relatives' ratings. Japanese patients with TBI overstimated self-care skills but not their ability to interact in socioemotional situations. Patients who had right and left CVA did not differ in their mean ratings of behavioral competency. Among all patient groups, there was no correlation between self-reported competencies and performance on a neuropsychological test. Family ratings of patients' behavioral competencies correlated with the patients' neuropsychological test performance. Post hoc analyses of patients with TBI suggest that speed of finger tapping related to an impaired self-awareness. Whereas cultural factors may influence self-reports of behavioral competency, patients across cultures with brain dysfunction seem to have reduced insight into their actual level of neuropsychological functioning.