Cardiac resynchronisation therapy reduces functional mitral regurgitation during dynamic exercise in patients with chronic heart failure: an acute echocardiographic study.

OBJECTIVES: To assess non-invasively the acute effects of cardiac resynchronisation therapy (CRT) on functional mitral regurgitation (MR) at rest and during dynamic exercise. METHODS: 21 patients with left ventricular (LV) systolic dysfunction and functional MR at rest, treated with CRT, were studied. Each patient performed a symptom-limited maximal exercise with continuous two dimensional Doppler echocardiography twice. The first exercise was performed with CRT; the second exercise was performed without CRT. Mitral regurgitant flow volume (RV), effective regurgitant orifice area (ERO) and LV dP/dt were measured at rest and at peak exercise. RESULTS: CRT mildly reduced resting mitral ERO (mean 8 (SEM 2) v 11 (2) mm(2) without CRT, p = 0.02) and RV (13 (3) v 18 (3) ml without CRT, p = 0.03). CRT attenuated the spontaneous increase in mitral ERO and RV during exercise (1 (1) v 9 (2) mm(2), p = 0.004 and 1 (1) v 8 (2) ml, p = 0.004, respectively). CRT also significantly increased exercise-induced changes in LV dP/dt (140 (46) v 479 (112) mm Hg/s, p < 0.001). CONCLUSION: Attenuation of functional MR, induced by an increase in LV contractility during dynamic exercise, may contribute to the beneficial clinical outcome of CRT in patients with chronic heart failure and LV asynchrony.

[Evaluation of the Beckman Coulter HmX hematology analyser at a general hospital]. / Evaluation de l'analyseur d'hématologie Beckman Coulter HmX dans un hôpital général.

The Beckman Coulter HmX is an hematological analyzer designed to provide a complete hematological profile including CBC, WBC differential (diff) and reticulocyte parameters. It has been evaluated in our laboratory over a two weeks period with three purposes: (1) a technical evaluation of the HmX performance, in regard to repeatability, linearity, carry over; (2) a comparison of numerical results (CBC, WBC diff) and analytical performance (flag sensitivity and specificity) with those obtained with the Coulter MaxM in use in our laboratory; (3) an analysis of the flagging algorithms using the blood smear as the reference method. The first part of the evaluation showed that the Beckman Coulter HmX is reproducible, and linear. The comparison between MaxM and HmX showed that the results given by the two instruments are similar and suggested that the Beckman Coulter HmX could replace the current hematology analyzer in use in our laboratory. The comparison of the flag system performance, between the Beckman Coulter HmX and the Coulter MaxM, has been performed with samples from three subgroups of patients (general departments, surgery and intensive care, hematological unit), and showed that the HmX is significantly more sensitive than the MaxM, with an higher global efficiency. The comparison of predictive values also showed a better performance of the HmX. In conclusion, the Beckman Coulter HmX is suited for an use in medium sized hospital laboratories (80 to 150 CBC diff/day), with good technical and analytical performance, a throughput of 75 samples/hr and a workstation allowing data management in accord with quality assurance guidelines in France.

Prospective evaluation of a simplified approach for common atrial flutter radio frequency ablation with only two catheters.

UNLABELLED: Intra-atrial conduction block within the inferior vena cava-tricuspid annulus isthmus (IVCT) has been shown to predict successful common atrial flutter ablation. However, its demonstration requires the use of several electrode catheters and mapping of the line of block. The aim of this study was prospectively to test the feasibility of a simplified ablation procedure using only two catheters. METHODS: Radio frequency (RF) ablation of common atrial flutter was performed in 30 patients with the sole use of a catheter for atrial pacing and a RF catheter. RF ablation lesions were created in the IVCT. Surface ECG criteria were used to monitor the conduction within the IVCT. The end point during low lateral atrial pacing was an increment in the interval between the pacing artefact and the peak of the R wave in surface lead II >50 ms and clockwise rotation of the P wave axis beyond -30 degrees and inferiorly. Then, the line of lesions was mapped during atrial pacing with the RF catheter. Additional RF lesions were applied if mapping disclosed a zone of residual conduction. Otherwise the procedure was stopped if mapping showed parallel double potentials all along the line. Finally, the block was reassessed with a 'Halo' catheter. RESULTS: Surface ECG criteria were met in 26 patients. Mapping the line of lesions showed a complete corridor of parallel double potentials in these 26 cases and in 3 of the 4 patients in whom ECG criteria were not met. Conduction evaluated with the Halo catheter showed bi-directional complete block in these 29 patients. After a follow-up of 16 +/- 4 months there was no recurrence of atrial flutter. CONCLUSION: Surface ECG criteria combined with mapping of the line of block demonstrate evidence of bi-directional IVCT block. This simplified RF ablation of common atrial flutter is feasible with a low recurrence rate.

[Primary familial pulmonary arterial hypertension]. / Hypertension artérielle pulmonaire primitive familiale.

The authors present the case of three young female patients, of the same family, with all quickly fatal Primary Pulmonary Hypertension (PPH). Their clinical signs and paraclinical investigations were suggestive of a PPH and excluded all others causes of Pulmonary Hypertension. These observations recall the possible familial cases of this rare and very severe disease. It emphasizes as well the possible revelation of the disease during or after a pregnancy. So the members of this family, essentially first the young women who wish to have children, need a medical detection.