Is conventional cardiac pacing harmful in patients with normal ventricular function?

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.