Pierluigi Zanco MD, Presenter: Nothing to Disclose

Renato Ometto MD, Abstract Co-Author: Nothing to Disclose

Piergiuseppe Orsolon MD, Abstract Co-Author: Nothing to Disclose

Gianfilippo Neri MD, Abstract Co-Author: Nothing to Disclose

Carlo Bonanno MD, Abstract Co-Author: Nothing to Disclose

Andrea Lupi MD, Abstract Co-Author: Nothing to Disclose

Matteo Salgarello, Abstract Co-Author: Nothing to Disclose

Alessandro Fontanelli, Abstract Co-Author: Nothing to Disclose

et al, Abstract Co-Author: Nothing to Disclose

In dilated cardiomyopathy (DC) the left ventricle function is aggravated by asynchronous contraction due to left bundle branch block (LBBB). Biventricular pacing (BP) induces improvement of cardiac function in these patients, but, the secondary changes on myocardial metabolism induced by BP are unclear at the moment. The aim of our study was to evaluate the possible changes on myocardial metabolism and perfusion induced by BP in these patients.

To this aim 22 patients (aged 54-80 yr, mean 68) affected by DC (III NYHA functional class and ejection fraction < 40%) and QRS duration above 150 ms, were submitted to cardiac PET in basal condition and 4-8 weeks after the implantation of a biventricular device. Metabolism was evaluated using F18-fluorodeoxyglucose (FDG)-PET, by the glucose load-insulin technique, by a dedicated PET scanner, and perfusion by N13-ammonia (NH3), injected at rest in 10 patients and by Tc-labeled perfusion tracer and SPECT in the other 12. A visual and a semi quantitative analysis were performed, calculating by ROIs the septum to lateral uptake ratio (SLR). The myocardial blood flow (MBF) was also calculated in ml/min/g using a dynamic acquisition and a modified Patlak method in the 10 patients evaluated using NH3-PET.

In all patients a selective defect in FDG uptake in the septum was present in basal condition (mean SLR 0.65±0.17) with a “reverse mismatch” with respect to perfusion (mean SLR 0.94±0.28, p<0.001). During BP the uptake of FDG in the septum improved (mean SLR 1.03±0.29 p<0.001 with respect to basal FDG-PET studies); on the contrary no significant changes were found in NH3 uptake (mean SLR 0.97±0.25). Mean ejection fraction increased from 27±7 to 38±7 (p<0.01). At the quantitative analysis the mean MBF in the septum did not show changes in basal condition and during BP (0.81±0.32 vs. 0.79±0.16; p=ns).

In patients affected by DC and LBBB, PET and SPECT revealed that resynchronization using BP improves the septal glucose metabolism and the cardiac function without significant changes in the myocardial blood flow.

Zanco, P, Ometto, R, Orsolon, P, Neri, G, Bonanno, C, Lupi, A, Salgarello, M, Fontanelli, A, et al, , PET and SPECT Evaluation of Cardiac Metabolism and Perfusion Changes Induced by Resynchronization Using Biventricular Pacing in the Patients Affected by Dilated Cardiomyopathy and Left Bundle Branch Block.  Radiological Society of North America 2004 Scientific Assembly and Annual Meeting, November 28 - December 3, 2004 ,Chicago IL. http://archive.rsna.org/2004/4403476.html