Fourier analysis in patients with different pacing modes

Area of Science:

• Cardiology
• Nuclear Medicine
• Biomedical Engineering

Background:

• Pacemakers are crucial for managing heart rhythm disorders.
• Different pacemaker modes can alter cardiac activation sequences.
• Assessing pacemaker-induced changes in cardiac function is clinically important.

Purpose of the Study:

• To evaluate the utility of phase analysis in identifying altered cardiac activation sequences due to various pacemaker pacing modes.
• To compare the diagnostic accuracy of phase analysis across different pacemaker types.

Main Methods:

• Radionuclide ventriculography and planar gated blood pool scintigraphy were performed in 56 patients with pacemakers.
• Phase analysis, including standard deviation of phase angle (sigma), was used to assess ventricular contraction and relaxation.
• Pacemaker impulse sites and diffusion within the heart were localized.

Main Results:

• Phase analysis demonstrated significant asynchronism of contraction and relaxation in VVI pacemaker patients compared to sinus rhythm (p < 0.001 for both ventricles).
• VVI rate-responsive pacemakers also showed significant asynchrony during pacing (p < 0.001).
• DDD pacemaker patients exhibited significant asynchrony during pacing, particularly in the right ventricle (p < 0.001).

Conclusions:

• Phase analysis is a valuable tool for detecting altered cardiac activation sequences induced by different pacemaker modes.
• Significant ventricular asynchrony is evident in patients with VVI and DDD pacemakers during pacing compared to sinus rhythm.
• This technique aids in localizing pacemaker impulse sites and understanding their impact on cardiac function.