Is conventional cardiac pacing harmful in patients with normal ventricular function?
Insights
Right ventricular pacing in patients with normal left ventricular function can lead to worsening functional capacity and quality of life over two years, despite no echocardiographic changes.
Area of Science:
- Cardiology
- Electrophysiology
- Medical Devices
Background:
- Right ventricular pacing's impact on patients with normal left ventricular function is not fully understood.
- Existing research primarily focuses on patients with pre-existing left ventricular dysfunction.
Purpose of the Study:
- To assess the long-term clinical and echocardiographic effects of pacemaker implantation in patients with previously normal left ventricular function.
- To identify potential adverse outcomes associated with high percentage of ventricular pacing.
Main Methods:
- Observational, cross-sectional study involving 20 patients with normal left ventricular function and >90% ventricular pacing.
- Prospective follow-up included New York Heart Association functional class, 6-minute walk test, B-type natriuretic peptide levels, echocardiography, and quality of life questionnaires over 24 months.
Main Results:
- Significant worsening in 6-minute walk test, functional class, and B-type natriuretic peptide levels observed at 24 months.
- Quality of life initially improved but declined by the end of the study period.
- No significant changes were noted in conventional or dyssynchrony echocardiographic parameters.
Conclusions:
- Conventional pacemaker implantation in this cohort was associated with a decline in functional status and quality of life.
- Increased B-type natriuretic peptide levels and QRS duration suggest a potential for subclinical cardiac strain.
- Further research is needed to explore alternative pacing strategies to mitigate long-term adverse effects.
Background:
Right ventricular pacing may be deleterious in patients with left ventricular dysfunction, but in patients with normal function the impact of this stimulation triggering clinically relevant ventricular dysfunction is not fully established.
Objectives:
To evaluate the clinical, echocardiographic findings of patients with previously normal left ventricular function underwent implantation of a pacemaker.
Methods:
Observational, cross-sectional study with 20 patients, who underwent implantation of pacemaker, prospectively followed-up, with the following inclusion criteria: normal left ventricular function defined by echocardiography and ventricular pacing higher than 90%. Were evaluated functional class (FC) (New York Heart Association), 6-minute walk test (6MWT), B-type natriuretic peptide (BNP), echocardiographic assessment (conventional and dyssynchrony parameters), and quality of life questionnaire (QLQ) (SF-36). The assessment was performed at ten days (t1), four months (t2), eight months (t3), 12 months (t4) and 24 months (t5).
Results:
Conventional echocardiographic parameters and dyssynchrony parameters showed statistically significant variation over time. The 6MWT, FC, and BNP showed worsening at the end of two years. QLQ showed initial improvement and worsening at the end of two years.
Conclusion:
The implantation of conventional pacemaker was associated with worsening in functional class, worsening in walk test, increased BNP levels, increased duration of QRS, and worsening in some domains of the QLQ at the end of two years. There were no changes in echocardiography measurements (conventional and asynchrony measures).
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