Comparative evaluation of left ventricular function in sick sinus syndrome on different long-term pacing modes

Area of Science:

• Cardiology
• Cardiac Electrophysiology
• Medical Device Technology

Background:

• Single-chamber ventricular pacing is suspected to contribute to congestive heart failure in patients with sick sinus syndrome (SSS).
• Understanding the precise role of pacing modality is crucial for patient management and preventing heart failure progression.

Purpose of the Study:

• To investigate the impact of different pacemaker pacing modes on the development of congestive heart failure in SSS patients.
• To quantitatively assess echocardiographic parameters related to cardiac function based on pacing modality.

Main Methods:

• A cohort of 51 SSS patients without structural heart disease received either atrial/dual-chamber (Group I, n=21) or ventricular pacemakers (Group II, n=30).
• Patients were matched for age, gender, heart rate, blood pressure, and pacing duration.
• Two-dimensional echocardiography was used to evaluate left atrial and left ventricular dimensions, volumes, ejection fraction, and wall stress after a mean follow-up of 64 months.

Main Results:

• Congestive heart failure developed in 1 patient in Group I and 3 patients in Group II.
• Group II patients exhibited a larger left atrium and left ventricular end-diastolic volume compared to Group I.
• No significant differences were observed in left ventricular end-systolic volume, ejection fraction, left ventricular mass, or systolic wall stress between the groups.

Conclusions:

• Pacing mode does not appear to influence left ventricular systolic function in patients with sick sinus syndrome.
• While some volumetric differences were noted, ventricular pacing did not lead to a higher incidence of congestive heart failure or impaired systolic function in this cohort.