Permanent and atrial-synchronized ventricular stimulation for clinically stable patients with normal or impaired left ventricular systolic function

The soluble suppression of tumorigenicity 2 as a biomarker of early cardiac remodeling in bradycardia patients receiving permanent pacemaker therapy

Aim: This study aims to evaluate: the difference of soluble suppression of tumorigenicity 2 (sST2) level, a biomarker for cardiac remodeling and echocardiography parameters value prior to and 1 month after implantation; and the association between pacemaker parameters and pacemaker mode along with delta sST2 levels. Materials & methods: This prospective cohort study enrolled all symptomatic bradycardia patients aged >18 years with preserved ejection fraction who underwent permanent pacemaker (PPM) implantation. Results: A total of 49 patients were included in this study. The sST2 level (ng/ml) were significantly different between prior and 1 month following PPM implantation (23.4 ± 28.4 vs 39.9 ± 63.7; p = 0.001). Conclusion: The early cardiac remodeling has occurred within 1 month after PPM implantation as indicated by increasing delta sST2 level.

Is right ventricular mid-septal pacing superior to apical pacing in patients with high degree atrio-ventricular block and moderately depressed left ventricular function?

OBJECTIVE

We are aimed to investigate whether right ventricular mid-septal pacing (RVMSP) is superior to conventional right ventricular apical pacing (RVAP) in improving clinical functional capacity and left ventricular ejection fraction (LVEF) for patients with high-degree atrio-ventricular block and moderately depressed left ventricle (LV) function.

METHODS

Ninety-two patients with high-degree atrio-ventricular block and moderately reduced LVEF (ranging from 35% to 50%) were randomly allocated to RVMSP (n=45) and RVAP (n=47). New York Heart Association (NYHA) functional class, echocardiographic LVEF, and distance during a 6-min walk test (6MWT) were determined at 18 months after pacemaker implantation. Serum levels of N-terminal pro-brain natriuretic peptide (NT-proBNP) were measured using an enzyme-linked immunosorbent assay (ELISA) kit.

RESULTS

Compared with baseline, NYHA functional class remained unchanged at 18 months, distance during 6MWT (485 m vs. 517 m) and LVEF (36.7% vs. 41.8%) were increased, but BNP levels were reduced (2352 pg/ml vs. 710 pg/ml) in the RVMSP group compared with those in the RVAP group, especially in patients with LVEF 35%-40% (for all comparisons, P<0.05). However, clinical function capacity and LV function measurements were not significantly changed in patients with RVAP, despite the pacing measurements being similar in both groups, such as R-wave amplitude and capture threshold.

CONCLUSIONS

RVMSP provides a better clinical utility, compared with RVAP, in patients with high-degree atrioventricular block and moderately depressed LV function whose LVEF levels ranged from 35% to 40%.

Is right ventricular outflow tract pacing superior to right ventricular apex pacing in patients with normal cardiac function?

BACKGROUND

Whether right ventricular outflow tract (RVOT) pacing is superior to right ventricular apex (RVA) pacing in terms of ventricular synchrony, cardiac function, and remodeling in patients with normal cardiac function is still unknown.

HYPOTHESIS

Right ventricular outflow tract pacing is superior to RVA pacing in patients with normal cardiac function.

METHODS

A total of 96 consecutive patients with high or third-degree atrial ventricular block were enrolled and randomized into 2 groups: RVOT pacing group (n = 48) and RVA pacing group (n = 48). Tissue Doppler imaging (TDI) and 2D echocardiography were performed to study left ventricular (LV) systolic and diastolic synchrony, LV volumes, and function.

RESULTS

There were no significant differences in baseline characteristics between the 2 groups. Left ventricular systolic asynchrony is more severe in the RVA pacing group than in the RVOT pacing group (P < 0.05), while diastolic synchrony is not significantly (NS) different between the 2 groups after pacing. There were no significant differences with respect to the mean myocardial systolic (Sm) and early diastolic velocities (Em), LV ejection fraction, LV end-diastolic and systolic volume in the 2 groups at 12 months of follow-up (all NS).

CONCLUSIONS

Although RVOT pacing caused more synchronous LV contraction compared with RVA pacing, it had no benefit over RVA pacing in aspect of preventing cardiac remodeling and preserving LV systolic function after 12 months of pacing in patients with normal cardiac function.

Difference in percentage of ventricular pacing between two algorithms for minimizing ventricular pacing: results of the IDEAL RVP (Identify the Best Algorithm for Reducing Unnecessary Right Ventricular Pacing) study

AIMS

Managed ventricular pacing (MVP) and Search AV+ are representative dual-chamber pacing algorithms for minimizing ventricular pacing (VP). This randomized, crossover study aimed to examine the difference in ability to reduce percentage of VP (%VP) between these two algorithms.

METHODS AND RESULTS

Symptomatic bradyarrhythmia patients implanted with a pacemaker equipped with both algorithms (Adapta DR, Medtronic) were enrolled. The %VPs of the patients during two periods were compared: 1 month operation of either one of the two algorithms for each period. All patients were categorized into subgroups according to the atrioventricular block (AVB) status at baseline: no AVB (nAVB), first-degree AVB (1AVB), second-degree AVB (2AVB), episodic third-degree AVB (e3AVB), and persistent third-degree AVB (p3AVB). Data were available from 127 patients for the analysis. For all patient subgroups, except for p3AVB category, the median %VPs were lower during the MVP operation than those during the Search AV+ (nAVB: 0.2 vs. 0.8%, P < 0.0001; 1AVB: 2.3 vs. 27.4%, P = 0.001; 2AVB: 16.4% vs. 91.9%, P = 0.0052; e3AVB: 37.7% vs. 92.7%, P = 0.0003).

CONCLUSION

Managed ventricular pacing algorithm, when compared with Search AV+, offers further %VP reduction in patients implanted with a dual-chamber pacemaker, except for patients diagnosed with persistent loss of atrioventricular conduction.