ABSTRACT
INTRODUCTION: Radionuclide ventriculography (RNV) evaluates segmental and global ventricular contractility and also detects conduction abnormalities. OBJECTIVE: To assess the temporal parameters of ventricular synchronization in the normal heart by a third harmonic (3H) Fourier phase analysis in a RNV and introduce this technique in our center. MATERIAL AND METHODS: Thirty normal subjects (19 men and 11 women) were included. An equilibrium RNV was performed in 35 degree left anterior oblique projection with 10 degree caudal tilt. The onset (T0); mean time (T(m)); total contraction time (T(t)); final time (T(f)) and propagation time (T(p)) for right (RV) and left ventricle (LV); as well as total propagation time (T(TP)); interventricular time (T(RV-LV)) and septum-lateral wall conduction time (T(S-LW)) were measured on the 3H Fourier histogram of the time-activity curve. RESULTS: Right ventricle contraction started 5 ms before that of the left ventricle (T(0RV) = 66 +/- 38 ms; T(OLV) = 71 +/- 30 ms), with a longer total contraction time (T(tVD) = 67 +/- 28 ms vs T(tVI) = 64 +/- 38 ms). Total propagation time (T(TP)) was 69 +/- 37 ms and the interventricular time (T(RV-LV)) was 2 +/- 25 ms. Contraction progressed from septum to lateral wall, with a septum-lateral wall conduction time (T(S-LW)) of 4 +/- 22 ms. CONCLUSION: Simultaneous contraction of right and left ventricles can be quantified by RNV phase analysis, providing a useful tool for ventricular resynchronization assessment in multisite pacing.
