Key result
Phase analysis demonstrated that ventricular pacing (VVI, VVI rate responsive, and DDD) significantly increased the standard deviation of phase angle compared to sinus rhythm (P<0.001).
Why the study?
Does phase analysis detect altered activation sequences induced by different pacing modes compared to sinus rhythm?
Observational (n=56)
Does phase analysis detect altered activation sequences induced by different pacing modes compared to sinus rhythm?
Phase analysis using radionuclide ventriculography effectively detects and quantifies the asynchronous ventricular contraction and relaxation induced by various pacing modes compared to sinus rhythm.
Answers are grounded in this paper and cite their sources.
Phase analysis may quantify pacing-induced dyssynchrony; leaves open its role in guiding mode selection.
The purpose of this study was to evaluate the usefulness of phase analysis in detecting the altered activation sequence induced by different pacing modes. Radionuclide ventriculography and planar gated blood pool scintigraphy were performed at rest in 56 patients with different pacemakers. This method permitted us to localize the pacemaker impulse site in the right ventricle and its diffusion in the heart. In patients with VVI pacemaker, this technique showed an evident asynchronism of contraction and relaxation of each ventricle and the standard deviation of phase angle (sigma), calculated by computer, is greater during pacing than sinus rhythm for left (LV) and right (RV) ventricles (LV sigma: 17 degrees +/- 4 vs 11 degrees +/- 3, less than 0.001; RV sigma: 31 degrees +/- 7 vs 14 degrees +/- 4, P less than 0.001). In the patients with VVI rate responsive pacemakers, the LV sigma changed from 18.5 +/- 3 under pacing to 11 degrees +/- 3 in sinus rhythm, P less than 0.001, while the RV sigma changed from 30 degrees +/- 8 to 14 degrees +/- 4, P less than 0.001. Instead in the patients with DDD pacemakers, the LV sigma changed from 15.5 degrees +/- 2 under pacing to 11 degrees +/- 3 in sinus rhythm, P less than 0.05, while the RV sigma changed from 29.1 degrees +/- 6 to 14 degrees +/- 4, P less than 0.001.(ABSTRACT TRUNCATED AT 250 WORDS)
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Santomauro et al. (1991) conducted an observational in Patients with different pacemakers (n=56). Different pacing modes (VVI, VVI rate responsive, DDD) vs. Sinus rhythm was evaluated on Standard deviation of phase angle (sigma) for left and right ventricles (p=<0.001). Phase analysis demonstrated that ventricular pacing (VVI, VVI rate responsive, and DDD) significantly increased the standard deviation of phase angle compared to sinus rhythm (P<0.001).
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