T. Lavergne

Reproducibility of the ventricular synchronization parameters assessed by multiharmonic phase analysis of radionuclide angiography in the normal heart.

Radionuclide angiography (RNA) permits analysis of contractility and conduction abnormalities. We determined the parameters of normal ventricular synchronization, assessed the reproducibility of the technique, and compared first harmonic (1H) and third harmonic (3H) analysis. Forty-four normal subjects (28 men and 16 women) were studied. RNA was performed in left anterior oblique (LAO) and left lateral (LL) projections. The onset (To), mean time (Tm), total contraction time (Tt) for right ventricle (RV) and left ventricle (LV), interventricular time (TRV−LV = TmLV − TmRV) in LAO, and the apex-to-base time (Ta−b) in LL were measured on the histograms of the time–activity curve. Reproducibility (R) was tested by studying 26 consecutive patients with two successive RNAs. RV starts contracting 25 ms before LV (ToRV = 29 ± 37 ms; ToLV = 54 ± 39 ms; mean ± SD) with a 37 ms longer total contraction time. TRV−LV is 3 ± 16 ms. In LL projection, apex and base contract synchronously: Ta−b = 2 ± 16 ms. 3H analysis enlarges all duration parameters (To, Tm and Tt), but does not alter synchronization (ΔTa−b and ΔTRV−LV between 1H and 3H <1%, p = NS). Reproducibility of the duration (TtLV and TtRV) and synchronization parameters (Ta−b and TRV−LV) is high (R ≤ 2.2%). In conclusion, the simultaneous contraction of right and left ventricles and of apex and base can be quantified by RNA phase analysis with high reproducibility. These results, consistent with published electrophysiological data, provide the basis for further non-invasive investigations of ventricular resynchronization in patients with basal electrical or mechanical asynchrony.

Traiter la fibrillation atriale dans l’insuffisance cardiaque

Treatment of patients with both atrial fibrillation and heart failure remains uneasy. In theory maintenance of sinus rhythm is desirable but the only pharmacological intervention able to do it safely is amiodarone. A trial of strategy randomisation, restoration of sinus rhythm or slowing of atrial fibrillation, has been done in patients with both atrial fibrillation and heart failure. This trial, named AF-CHF has shown neutral results, the 2 strategies, rhythm control or simple rate control were similar in terms of mortality. Dronedarone is an innovative drug bringing new possibilities in the treatment of atrial fibrillation but it is contra-indicated in case of severe heart failure. Another possible approach is that of non pharmacological techniques. Sinus rhythm maintenance may be obtained by pulmonary vein isolation. The other possibility is the ablation of atrio-ventricular node with implantation of a pacemaker, technique which is reserved to selected patients.