[New systems of mapping and navigation in electrophysiology]. / Nouveaux systèmes de cartographie et de navigation en électrophysiologie.

The indications of radiofrequency ablation of arrhythmias have considerably increased since the introduction of the technique in the early 1990s. Interventional rhythmologists now treat arrhythmias which are more and more complex by their mechanism. This requires accurate representation of the ablation catheter position and the integration of spatial and temporal data to identify the arrhythmogenic substrate. The systems of mapping and navigation developed over the last ten years are important tools for interventional rhythmologists. They are very useful for the identification of complex arrhythmogenic substrates which require "individualised" ablations in specific cases. The aim of this article is to review different systems of mapping, and/or navigation currently on the market and their principal characteristics without entering into the details of their use in interventional electrophysiology.

[Benefits of a beta-blocking agent (carvedilol) on bilateral atherosclerotic renal artery stenosis. A case report]. / Effet d'un traitement bêtabloquant (carvédilol) en cas de sténoses bilatérales des artères rénales. A propos d'une observation.

A 77 year old man with coronary artery disease was referred to our institution for recurrent (flash) episodes of pulmonary edema due to malignant hypertension. A selective contrast-enhanced angiography showed severe bilateral renal artery stenosis. We also found a high level of plasma renin production identifying intense renin-angiotensin system activation. We first considered revascularisation. Percutaneous intervention initially failed and thereafter the patient denied surgical revascularisation. We have then recommended medical therapy, namely a beta-blocker after adequate correction of fluid retention. We used CARVEDILOL which has no nephrotoxicity and effectively inhibit the renin-angiotensin system. The patient feels significant functional and clinical improvement with no fluid retention relapse with a follow-up of more than 18 months.

Correlation between electrogram morphology and standard criteria to validate bidirectional cavotricuspid block in common atrial flutter ablation.

AIM: Assessment of a bidirectional conduction block within the cavotricuspid isthmus (CTI) is critical during radiofrequency (RF) atrial flutter (AF) ablation. We investigated the use of bipolar atrial electrogram (BAE) morphology as an additional criterion identifying CTI block and tested it against two recognized criteria: differential pacing and reversal of the right atrial depolarization sequence during coronary sinus (CS) pacing. METHODS AND RESULTS: An RF ablation procedure was performed during 600 ms CS pacing in 100 consecutive patients with a common AF. BAE recorded along the CTI were continuously monitored. CTI conduction block was achieved by RF ablation in all patients and a clear change in BAE polarity in the Electrogram recorded by the dipoles located on the CTI and immediately lateral to the intended line of block (RS to QR pattern) associated with a confirmed CTI conduction block was observed in all cases. BAE morphology changes predicted bidirectional CTI conduction blocks with a 100% positive and a 100% negative predictive value. At a mean follow-up of 33 +/- 11 months, there was a 5% AF recurrence rate. CONCLUSIONS: Our study suggests that morphological changes in BAE recorded at sites lateral and adjacent to the target line of block may be used as a unique and robust criterion to validate CTI conduction block during AF ablation procedure.

[Severe cardiac insufficiency and type Ib pseudohypoparathyroidism]. / Insuffisance cardiaque sévère et pseudo-hypoparathyroïdisme de type Ib.

The authors report the case of a 28 year old woman with acute left ventricular failure associated with severe hypocalcaemia (1.7 mmol/l) without chronic renal failure or hypoproteinaemia. The echocardiographic appearances were those of dilated and globally hypokinetic cardiomyopathy with a severely depressed left ventricular ejection fraction (23%). Haemodynamic improvement was only obtained by the association of calcium supplements and Vitamin D derivatives (Un-Alfa) to conventional treatment. A low serum calcium associated with hyperphosphotaemia, hypocalciuria, hypophosphaturia and, above all, a high parathormone concentration, provided the diagnosis of a sporadic form of type Ib pseudohypoparathyroidism. Secondary cardiac failure to the hypocalcaemia is mainly observed in children and young adults in the context of chronic renal failure or true hypoparathyroidism. Pseudohypoparathyroidism is a very rare condition and systolic LV dysfunction for which hypocalcaemia is responsible, would seem to be totally reversible after calcium supplementation.

[Myocardial infarction following a bee sting. Apropos of a case and review of the literature]. / Infarctus du myocarde consécutif à une piqûre d'abeille. A propos d'un cas et revue de la littérature.

The authors report a case of limited inferior myocardial infarction in a young man following a bee sting. Coronary angiography, performed following the acute phase, showed angiographically healthy coronary arteries and minimal sequelae of myocardial necrosis in the inferior territory. The pathogenic role of the bee sting in myocardial necrosis was suggested by the timing of the events. The probable mechanism responsible for this myocardial infarction was severe coronary arterial spasm (partly mediated by psychological stress related to the intensity of the anaphylactic reaction) with secondary in situ thrombosis probably facilitated by cardiovascular collapse. The role of anaphylaxis, generating acute coronary insufficiency, is discussed in the light of this clinical case.

[Early detection of cardiotoxicity of anthracyclines. Value of isotopic method]. / Détection précoce de la toxicité cardiaque des anthracyclines. Intérêt de l'étude isotopique.

Anthracyclines are antitumoral agents whose therapeutic efficacy is limited by dose-dependent cardiotoxicity. Thirty-one adult patients treated with long-term anthracycline were included in a prospective study to evaluate the ejection fraction and certain parameters of left ventricular diastoclic function by radionuclide angiography, and the left ventricular phase by Fourier's method. Scintigraphic acquisitions were obtained before starting and four weeks after ending chemotherapy. A significant decrease in the maximal velocity of early diastolic filling (2.84 +/- 0.57 to 2.49 +/- 0.45 VTD/s; p < 0.01), the ejection fraction also fell from 57.6% +/- 4.7% to 53.8% +/- 4.6% (p < 0.01). No significant changes in early diastolic filling time or analysis of left ventricular phase with respect to standard deviation (p > 0.05) were observed. In addition, the change in maximal velocity of early diastolic filling did not correlate with the reduction in ejection fraction. Therefore, left ventricular diastolic dysfunction is probably an early marker for anthracycline cardiotoxicity, the sensitivity of which is close to that of the ejection fraction in the detection of infraclinical cardiotoxicity.

Impairment of diastolic function during short-term anthracycline chemotherapy.

OBJECTIVE: To assess the early changes in left ventricular diastolic and systolic function due to anthracycline treatment. DESIGN: A prospective study of cardiac function by radionuclide angiography in adults before and one month after the end of anthracycline treatment. PATIENTS: 60 patients without cardiac disease treated with chemotherapy containing anthracycline. METHODS: Cardiac function was assessed by radionuclide measurement throughout treatment. Ejection fraction, peak ejection rate, time to peak ejection rate, filling rate, and time to peak filling rate were measured before and after treatment. To normalise radionuclide measurements of the left ventricular diastolic function the ratio of the filling rate to the ejection fraction and the ratio of the filling rate to the peak ejection rate were calculated. RESULTS: No patient developed symptomatic congestive cardiac failure. The ejection fraction decreased from 58% (5%) to 55% (6%) (P < 0.001), the peak ejection rate fell from 2.99 (0.41) to 2.77 (0.41) of the end diastolic volume per second (P < 0.001), and the peak filling rate from 2.71 (0.47) to 2.55 (0.44) of the end diastolic volume per second (P < 0.01) after treatment. No difference was observed in the normalised ratios. CONCLUSIONS: This report shows simultaneous impairment of left ventricular systolic and diastolic radionuclide parameters. The absence of variation in normalised measurements suggests similar changes in ejection fraction, peak ejection rate, and peak filling rate throughout treatment.