Effects of atrial electromechanical delay and ventriculoatrial conduction over the atrial functions in patients with frequent extrasystole and preserved ejection fraction

Assessment of atrial conduction times in patients with frequent premature ventricular complex

Background

Premature ventricular complex (PVC) is a frequent finding in the general population. The atrial conduction time (ACT) is the period between the electrocardiographic P wave and the atrial mechanical contraction, and its prolongation indicates an atrial electromechanical delay (EMD). In our study, we compared atrial conduction parameters by echocardiographic methods between patients with frequent PVC and healthy control subjects.

Methods

The study included 54 patients with PVC and 54 healthy volunteers. Atrial conduction parameters were measured with echocardiographic examination. The time difference between the p wave and the Am wave was measured in the septal, lateral, and tricuspid annulus regions. The interatrial EMD, left atrial intra-atrial delay, and the right atrial intra-atrial delay were calculated from these measurements. The groups were compared for demographic and electrocardiographic features and echocardiographic parameters.

Results

Left intra-atrial EMD, right intra-atrial EMD, and interatrial EMD were significantly longer in the patient group (p = .001, p < .001, p < .001, respectively). PA lateral, PA septal, and PA tricuspid durations were significantly prolonged in the patient group (all p < .001). All ACT parameters were significantly prolonged in patients with PVC QRS duration of 150 ms and above (all p < .001). All ACT parameters were prolonged in PVCs of right ventricular origin than those of left ventricular origin (all p < .001). ACT parameters were prolonged in patients with a coupling interval time below 485 ms (all p < .001).

Conclusions

Atrial conduction times are prolonged in patients with frequent PVC.

The effects of catheter ablation of outflow tract premature ventricular complexes on atrial electromechanical delay

BACKGROUND

Consistent data from several studies have shown that catheter ablation of frequent premature ventricular complexes (PVCs) results in substantial improvement in left ventricular ejection fraction (LVEF), left ventricular diastolic function, and left atrial volume and mechanics. However, the effects of catheter ablation of PVCs on atrial electromechanical properties have not been documented yet.

AIMS

In the present study, we investigated the short-term effects of radiofrequency catheter ablation (RFCA) of outflow tract PVCs on atrial electromechanical delay (EMD).

METHODS

A total of 71 subjects with idiopathic outflow tract PVCs who underwent RFCA were included. Interatrial and intra-atrial EMDs were measured by tissue Doppler imaging before and 3 months after catheter ablation.

RESULTS

The study population was divided into normal ejection fraction (EF) and low-EF subgroups according to their LVEF. In all study groups, substantial improvement was found in lateral electromechanical coupling time (PA), septal PA, right ventricular PA, interatrial EMD, left-sided intra-atrial EMD, and right-sided intra-atrial EMD. No treatment heterogeneity was observed when comparing low-EF and normal-EF subgroups with respect to atrial EMDs (interatrial EMD, interaction p = .29; left-sided intra-atrial EMD, interaction p = .13; right-sided intra-atrial EMD, interaction p = .88).

CONCLUSION

RFCA of outflow tract PVC has a favorable early effect on intra- and inter-atrial EMDs irrespective of preprocedural LVEF.

Impaired left ventricular global longitudinal strain improves with radiofrequency catheter ablation in patients with PVC-induced cardiomyopathy

BACKGROUND

In our study, we aimed to evaluate left ventricular global longitudinal strain (LV-GLS) value in patients with premature ventricular contractions (PVCs) and reduced LV ejection fraction (LVEF) and to determine the effect of radiofrequency catheter ablation (RFA) procedure on LV-GLS.

METHODS

In this cross-sectional study, 150 patients who underwent three-dimensional RFA with the diagnosis of PVCs were included. LV-GLS was measured with strain echocardiography in all patients before RFA and in the sixth-month control. Patients included in the study were grouped as LVEF <50% (Group I) and LVEF ≥50% (Group II) according to baseline LVEF, and patients within Group I were grouped as LVEF <50% (Group A) and LVEF ≥50% (Group B) according to the sixth-month LVEF.

RESULTS

There were 39 patients (26%) with baseline LVEF <50%. In 14 (36%) of these patients, LVEF <50% was observed to continue during the sixth-month controls. Both the baseline and sixth-month LV-GLS values were significantly lower in Group I patients (<0.01). RFA treatment significantly increased both LVEF and LV-GLS (<0.01). It was found that age, N-terminal pro-brain natriuretic peptide, LV diameters, and baseline LVEF were higher, and baseline LV-GLS level was lower in Group A patients (P < .01). Baseline LVEF and LV-GLS values were found to independently determine the patients in Group A (P < .01). In receiver operator characteristic analysis, when the limit value is accepted as 40% for baseline LVEF and 18% for baseline LV-GLS, it can determine Group A with acceptable sensitivity and specificity.

CONCLUSIONS

LV-GLS decreases significantly in patients with reduced LVEF and PVCs. In these patients, RFA treatment significantly increases both LVEF and LV-GLS.