Pentraxin 3 in primary percutaneous coronary intervention for ST elevation myocardial infarction is associated with early irreversible myocardial damage : Kinetic profile, relationship to interleukin 6 and infarct size.

BACKGROUND: The inflammatory marker long pentraxin 3 (PTX3) has been shown to be a strong predictor of 30-day and one-year mortality after acute myocardial infarction. The aim of this study was to evaluate the kinetic profile of PTX3 and its relationship with interleukin 6 (IL-6), high-sensitive C-reactive protein (hs-CRP) and infarct size. METHODS: PTX3, IL-6 and hs-CRP were measured at predefined time points, at baseline (before percutaneous coronary intervention (PCI)), at 12 and 72 hours after PCI in 161 patients with first-time ST elevation myocardial infarction (STEMI). RESULTS: PTX3 and IL-6 levels increased in the early phase, followed by a gradual decrease between 12 and 72 hours. There were statistically significant correlations between PTX3 and IL-6 in general, for all time points and for changes over time (0-72 hours). In a linear mixed model, PTX3 predicted IL-6 (p < 0.001). PTX3 is also correlated with hs-CRP in general, and at each time point post PCI, except at baseline. PTX3, IL-6 and hs-CRP were all significantly correlated with infarct size in general, and at the peak time point for maximum troponin I. In addition, there was a modest correlation between IL-6 levels at baseline and infarct size at 72 hours after PCI (ρ = 0.23, p = 0.006). CONCLUSIONS: PTX3 had a similar kinetic profile to IL-6, with an early increase and decline, and was statistically significantly correlated with markers of infarct size in STEMI patients post primary PCI. Baseline levels of IL-6 only predicted infarct size at 72 hours post PCI.

[Pathology and dental care in the context of cardiovascular conditions: myths, beliefs and realities]. / Pathologies et soins dentaires dans le cadre des affections cardiovasculaires: mythes, croyances et réalités.

The knowledge regarding the links between dental and cardiac affections are generally based on empirical concepts and lead to unjustified clinical practices. Infectious endocarditis (IE) is the principal cardiac diseases concerned with dental procedures. Although in France, the incidence of IE is stable, the incidence of oral bacteria at the origin of IE is diminishing. The risk of IE and thus the indication of antibioprophylaxis depend upon the subjacent cardiopathy and dental treatment. Antibioprophylaxis has to be very strict in patients with high or moderate risks of IE but is not necessary in low risk patients. In all cases, a good oral and dental hygiene and a regular dentist follow up are the most effective methods of preventing IE. Coronary artery disease and dental affections are associated because they present similar risk factors (i.e. smoking, excessive sugar consumption) and also because inflammation increases the risk of acute coronary syndrome. Today, dental cares are not contraindicated in patients with recent coronary syndrome if precise protocols are followed. Concerning the hemorrhagic risk during dental care in patients treated by anticoagulants and/or antithrombotics, dental cares and extractions are possible if INR or heparinemy are within the therapeutic limits and local haemostasis is meticulous. In addition, aspirin does not require to be stopped before minor dental treatments. Finally a better collaboration between dentists and cardiologists would allow an optimum management of patients with cardiac disease requiring dental cares.

Aortic stenosis with severe left ventricular dysfunction and low transvalvular pressure gradients: risk stratification by low-dose dobutamine echocardiography.

OBJECTIVES: We sought to assess risk stratification by using dobutamine stress echocardiography (DSE) in patients with aortic stenosis (AS) and severe left ventricular (LV) dysfunction. BACKGROUND: Few data are available on risk stratification for valve replacement in patients with AS, LV dysfunction and low transvalvular gradients. METHODS: Low-dose DSE was performed in 45 patients (16 women and 29 men; median [quartile range] age in years: 75 [69 to 79]; left ventricular ejection fraction: 0.29 [0.23 to 0.32]; aortic valve area [cm2]: 0.7 [0.5 to 0.8]; mean transaortic gradient [mm Hg]: 26 [21 to 33]). Patients were classified into two groups: group I (n = 32, LV contractile reserve on DSE) and group II (n = 13, no contractile reserve). Valve replacement was performed in 24 and 6 patients in groups I and II, respectively. RESULTS: Perioperative mortality was 8% in group I and 50% in group II (p = 0.014). Survival at five years after the operation was 88% in group I. Compared with medical therapy, valve surgery was associated with better long-term survival in group I (hazard ratio for death [HR-D] 0.13, 95% confidence interval [CI] 0.002 to 0.49) and reduced survival in group II (HR-D 19.6, 95% CI 2.7 to 142). The effect of valve surgery on survival remained significant in both groups after adjustment for age, diabetes, respiratory disease and hypertension. Medical therapy had the same effect in both groups. CONCLUSIONS: In patients with AS, LV dysfunction and low transvalvular gradients, contractile reserve on DSE is associated with a low operative risk and good long-term prognosis after valve surgery. In contrast, operative mortality remains high in the absence of contractile reserve.

[Left ventricular functional imagery by magnetic resonance. Applications and developments]. / Imagerie fonctionnelle du ventricule gauche par résonance magnétique. Applications et développements.

Technical developments have considerably reduced the acquisition time and have improved the quality of magnetic resonance imaging. The recent recommendations of the European Society of Cardiology place MRI in the front line of investigations for the diagnosis and evaluation of congenital heart disease, cardiac tumours and pathology of the pericardium and great vessels. With the possibility of obtaining oblique planes in all 3 dimensions, MRI is the reference for the measurement of left ventricular mass, volumes, and ejection fraction, with the major advantage of not depending on hypotheses of left ventricular geometry. In addition to these known applications, the development of functional cardiac MRI has led to significant advances in the study of regional myocardial function and perfusion. The aim of this article is to discuss present indications and the potential developments of functional cardiac MRI, focusing on the quantitative evaluation of myocardial function and perfusion.

[Hospital mortality in cardiology. Analysis of deaths occurring in the Federation of Cardiology of a university hospital center]. / Mortalité hospitalière en cardiologie. Analyse des décès survenus au sein de la fédération de cardiologie d'un centre hospitalo-universitaire.

The aim of this study was to examine the nature of cardiovascular deaths occurring in a University Hospital. All the hospital files of 1999 of the Federation of Cardiology of Henri Mondor Hospital, Creteil, of patients who died in the department or after transfer to the intensive care unit or cardiac surgery department, were analysed. Myocardial ischaemia was the leading cause of death, occurring either in the acute phase of transmural infarction or in patients with chronic cardiac failure. Deaths occurring during acute myocardial infarction were associated with late treatment and/or non-reperfusion of the culprit artery. The delay of diagnosis seemed to be secondary to late consultation or difficulty in diagnosis. This resulted in severe left ventricular dysfunction and, in a quarter of cases, mechanical complications. They led to the early death of the patients (2.9 +/- 3.5 days after admission). Campaigns of patient information and education of doctors who see these patients would seem to be the most appropriate approach to reduce the delay before hospital admission in order to reduce mortality related to myocardial infarction. Cardiac failure is a common cause of death in cardiology departments. The deaths of patients occurred after a long follow-up and several days after hospital admission (11 +/- 10 days). Optimisation of the treatment of cardiac failure, the investigation of ischaemic heart disease, the search for new therapeutic strategies of acute cardiac failure and information of patients about their disease, seem to be the principal measures to take to improve the poor prognosis of this disease.

Prediction of functional recovery of viable myocardium after delayed revascularization in postinfarction patients: accuracy of dobutamine stress echocardiography and influence of long-term vessel patency.

OBJECTIVES: We sought to evaluate dobutamine stress echocardiography (DSE) for predicting recovery of viable myocardium after revascularization with cineangiography as a gold standard for left ventricular (LV) function. We studied the influence of late vessel reocclusion on regional LV function. BACKGROUND: Dobutamine stress echocardiography is a well established evaluation method for myocardial viability assessment. In previous studies the reference method for assessing LV recovery was echocardiography, long-term vessel patency has not been systematically addressed. METHODS: Sixty-eight patients with a first acute myocardial infarction (AMI) and residual stenosis of the infarct related artery (IRA) underwent DSE (mean +/- standard deviation) 21 +/- 12 days after AMI to evaluate myocardial viability. Revascularization of the IRA was performed in 54 patients by angioplasty (n = 43) or bypass grafting (n = 11). Coronary angiography and LV cineangiography were repeated at four months to assess LV function and IRA patency. RESULTS: Sensitivity and specificity of DSE for predicting myocardial recovery after revascularization were 83% and 82%. In the case of late IRA patency, specificity increased to 95%, whereas sensitivity remained unchanged. In the 16 patients with myocardial viability and late IRA patency, echocardiographic wall motion score index decreased after revascularization from 1.83 +/- 0.15 to 1.36 +/- 0.17 (p = 0.0001), and left ventricular ejection fraction (LVEF) increased from 0.52 +/- 0.06 to 0.57 +/- 0.06 (p = 0.0004), whereas in five patients, reocclusion of the IRA prevented improvement of segmental or global LV function despite initially viable myocardium. CONCLUSIONS: Dobutamine stress echocardiography is reliable to predict recovery of viable myocardium after revascularization in postinfarction patients. Late reocclusion of the IRA may prevent LV recovery and influence the accuracy of DSE.

[Coronary microcirculation. Physiologic and pathologic aspects]. / Microcirculation coronaire. Aspects physiologique et pathologique.

The coronary circulation has a protective regulation system which, in extreme haemodynamic conditions, compensates increased myocardial oxygen demand. The coronary reserve, based on this concept defines the capacity of the system to increase flow temporally, and, thereby, myocardial oxygen supply. The introduction of new methods of investigating the coronary microcirculation has enabled the study of this phenomenon in several cardiovascular pathologies. Two types of investigation are used currently for studying the coronary microcirculation: 1) invasive methods, especially the recently developed intracoronary Doppler and pressure guide, 2) non-invasive methods, and, in particular, contrast echocardiography, position emission tomography and magnetic nuclear resonance. These investigations allow measurement of the coronary reserve or the assessment of the myocardial consequences of abnormalities of the microcirculation. Some workers use these methods to investigate pathological coronary microcirculation in different cardiomyopathies, in the presence of different cardiovascular risk factors (hypertension, diabetes, smoking, hypercholesterolaemia) and after cardiac transplantation.

Local gene delivery within the media of rabbit iliac arteries by using the infiltrator intramural delivery device.

Percutaneous transluminal angioplasty continues to be limited by restenosis. Prevention of restenosis is now focusing on local delivery of therapeutic agents, such as proliferation-inhibiting genes, directly to the site of arterial injury. We evaluated use of the Infiltrator catheter (IVT, San Diego, CA. U.S.A.) for gene delivery within the arterial media. The goals of our study were to evaluate the histologic effects of the injection and the suitability of the Infiltrator catheter for local delivery of viral therapy. We injected the femoral arteries of 21 New Zealand White rabbits. Six animals were used for an evaluation of the intramural distribution of dextran/rhodamine injected via the Infiltrator catheter. In seven animals, injection site histology and in vitro vasoreactivity were studied after an injection of saline. In the remaining eight animals, a replication-deficient adenovirus encoding for the firefly luciferase gene (Ad RSVLuc) was injected, and luciferase activity was quantified 3 and 8 days later. After injection via the Infiltrator catheter, the fluorescent tracer was distributed throughout the entire circumference and width of the arteries. Histologic examination showed minimal damage with partial endothelial abrasion and disruption of the internal elastic lamina confined to the penetration sites. In vitro endothelium-dependent vasodilation was present at a reduced level after injection via the Infiltrator (maximal endothelium-dependent acetylcholine-induced relaxation, 51.5 +/- 7.4% vs. 23.8 +/- 14.6%; p < 0.05). Significant luciferase expression was found in all the arteries, with a significant increase from day 3 to day 8 (5,392.5 +/- 2,300 vs. 2,012 +/- 471 cpm/mg; p < 0.05). These data obtained in a rabbit iliac artery model show that the Infiltrator catheter is an efficient and safe local intramural delivery device that provides significant transgene expression in the arterial wall without causing significant structural damage.

Angioscopy variables predictive of early angiographic outcome after excimer laser-assisted coronary angioplasty.

This study attempted to determine whether anatomic findings at angioscopy were associated with adverse early angiographic outcomes following excimer laser-assisted coronary angioplasty. Predictive factors of either coronary abrupt vessel closure or early (< or =24 hours) restenosis after percutaneous coronary angioplasty, including clinical and angiographic variables, have been widely evaluated. The role of angioscopic findings may contribute to identification of patients at risk for early poor outcome. Thirty-seven patients with severe lesions, including 23 total occlusions which underwent successful percutaneous transluminal coronary angioplasty (PTCA) with laser irradiation and adjunctive balloon dilatation (n = 35), or stand alone laser (n = 2), had concomitant angioscopic imaging of the target vessel. All patients had a 24-hour angiographic follow up. Early unfavorable outcome (n = 15) was defined as abrupt vessel closure or restenosis (> or = 50% stenosis) at 24 hours. By multivariate logistic regression analysis, immediate post-PTCA residual percent stenosis was associated with a poor outcome (restenosis: 33 +/- 22% vs no restenosis: 21 +/- 14%, p = 0.05). Angioscopic red thrombus aspect was the most significant correlate for early closure or restenosis (7 of 15 patients with unfavorable outcome vs 2 of 22 patients with favorable outcome, odds ratio, 22.9; p < 0.01) and was associated with a significantly higher early minimal lumen diameter loss (1 +/- 0.8 mm in the presence of a red thrombus vs 0.3 +/- 0.5 mm without thrombus, p < 0.005). Red thrombus appearance is associated with an unfavorable early angiographic outcome in patients who undergo laser-assisted coronary angioplasty.

Sympathetic stimulation overrides flow-mediated endothelium-dependent epicardial coronary vasodilation in transplant patients.

BACKGROUND: Abnormal coronary vasomotor responses have been described in transplant patients. The aim of this study was to evaluate the graft epicardial vasomotor responses to different stimuli that increase coronary blood flow. METHODS AND RESULTS: Twelve heart transplant recipients with angiographically normal epicardial coronary arteries were compared 2.7 +/- 1.2 months after surgery with 6 control subjects. Coronary flow velocity was measured with a guidewire Doppler. Coronary diameter changes of the proximal and midportion of the left anterior descending coronary artery were assessed by quantitative coronary angiography during rapid atrial pacing, cold pressor test, supine exercise, and subselective infusion of papaverine and after intracoronary injection of linsidomine (SIN-1). Catecholamine plasmatic levels were determined at the different stages of the protocol. In 6 other transplant patients, a cold pressor test was performed before and after intracoronary infusion of phentolamine (10 micrograms.kg-1.min-1). Coronary flow velocity increased significantly in both groups during each phase of the protocol. In control subjects, dilation was observed in response to atrial pacing (8.7 +/- 7.6%; P < .05), CPT (8.8 +/- 2.3%; P < .01), exercise (14.5 +/- 9.4%; P < .001), and papaverine infusion (14.2 +/- 6.1%; P < .001) and after injection of SIN-1 (26.8 +/- 11.9%; P < .001). In transplant patients, similar dilation was observed during atrial pacing (8.2 +/- 8.3%; P < .05) and papaverine infusion (14.6 +/- 7.8%; P < .001) and after SIN-1 (25.8 +/- 10.8%; P < .001). CPT and exercise caused slight constriction (-3.5 +/- 4.5% and -2.7 +/- 10.5%, respectively; both P < .001 versus control subjects). Norepinephrine plasmatic levels increased in both groups during CPT and exercise. Slight constriction during the cold pressor test (-4.5 +/- 9.6%) changed to dilation (6.8 +/- 7.0%) after alpha-blockade with phentolamine (P < .001). CONCLUSIONS: These results show that flow-mediated, endothelium-dependent vasodilation is preserved early after trans-plantation. Sympathetic stimulation, which overrides the endothelium-dependent mechanism, can be related to hypersensitivity to catecholamines due to denervation.

Clinical implantation of the wearable Baxter Novacor ventricular assist system.

Implantation of the wearable Novacor electrically powered left ventricular assist system was performed on March 16, 1993, in a 44-year-old man hospitalized for an acute episode of myocardial decompensation after a 6-year history of dilated cardiomyopathy. He was rehabilitated fully and became ambulatory, awaiting a suitable cardiac graft for 59 days. He is now back to work, enjoying a normal life. This case illustrates the progress made by miniaturization of the external components of the system. General acceptance of the system and psychological adaptation to the new way of life were remarkable.

Oxidative stress in patients with unstable angina.

The aim of this study was to determine whether oxidative stress occurs in unstable angina. Thirty patients with unstable angina class B (Braunwald classification) were prospectively studied. Control groups consisted of 23 patients presenting with stable angina and of 21 age-matched healthy volunteers. Upon admission and every 8 h for 24 h, blood samples were drawn for the determination of plasma malondialdehyde (MDA) levels, Se-glutathione peroxidase (GPX) activity, erythrocyte reduced glutathione (GSH) concentrations, erythrocyte GPX and superoxide dismutase (SOD) activities. Coronary angiograms were performed within 4 days of admission in 26 out of the 30 patients included in the study. Nine of these 30 patients were subsequently identified as presenting a non-Q wave myocardial infarction and were separately examined. On admission, only plasma MDA levels and erythrocyte GSH concentrations differed among groups. Plasma MDA levels of patients presenting with unstable angina (P < 0.01) and acute myocardial infarction (P < 0.05) were higher than those of patients with stable angina and of normal volunteers, whereas there was no difference in these parameters between unstable angina and non-Q wave myocardial infarction groups. Erythrocyte GSH concentration was lower in all patient groups as compared to normal subjects. ANOVA for repeated measures showed no difference between admission and subsequent levels for all parameters. Finally, no difference was observed for any of the parameters when anti-ischaemic or anti-aggregant treatment before admission, or the number of affected vessels on coronary angiograms, were considered. We conclude that an oxidative stress can be evidenced in patients with unstable angina or acute myocardial infarction.

Excimer and holmium yttrium aluminum garnet laser coronary angioplasty.

Recently access to the coronary arteries became available to laser angioplasty because of a new technique utilizes a pulsed laser source and multifiber, "over-the-wire" guided catheters. The aim of this study was to evaluate the early and long-term results and the side effects of coronary angioplasty with an excimer or a Ho-YAG laser. Forty consecutive patients were treated with the Ho-YAG laser (group I) and 46 consecutive patients were treated with the excimer laser (group II). The primary laser angioplasty success rate was 55% and 72% (NS) for groups I and II, respectively. This success rate was highest in saphenous vein grafts. It was similar in calcified and noncalcified lesions and in total occlusions and stenoses. It tended to be lower in long lesions than in short ones (40% vs 60%; p < 0.05 and 44% vs 78%; NS for groups I and II, respectively). Laser stand-alone therapy was performed in 5% of patients in group I compared with 22% in group II (p < 0.05). Failures were due to the inability of the laser catheter tip to reach the lesion, to cross the obstruction, or to obtain a significant reduction in stenosis. They were more frequent in patients in group I than in those in group II (45% vs 28%). There were no deaths, no myocardial infarctions, and no need for emergency coronary artery bypass grafting because most patients had total occlusions or a well-protected coronary artery. Complications included acute closure in 8% of patients in group I and in 17% of patients in group II and spasm in 10% and 13% of patients in groups I and II, respectively. Dissection occurred more frequently in patients in group II than in those in group I (28% vs 7%; p < 0.04). The angiographic patency rate at 6-month follow-up was 33% and 29% for patients groups I and II, respectively. Multifiber, wire-guided catheters provide easy access to the coronary arteries. Excimer laser angioplasty is effective but induces a high rate of dissections. Technical improvements are required to ablate more tissue to possibly reduce the restenosis rate. Further studies are needed to elucidate the mechanism of side effects and to reduce the restenosis rate.

[Emergency aorto-coronary bypass after myocardial infarction]. / Pontages aorto-coronaires en urgence au décours de l'infarctus aigu du myocarde.

During a recent three-year period, 37 patients had an emergent aortocoronary bypass (ACB) after evolutive acute myocardial infarction. The patients are divided up into two groups: group I includes 12 patients who were operated after the failure of early thrombolysis; group II includes 25 patients operated after the failure of revascularization through percutaneous angioplasty. In group I, all patients survived and 9 had no postoperative complications. In group II, the outcome was favorable for 16 patients. Long-lasting postoperative inotropic support was required for nine patients. Two patients died early. In all patients of the study, surgery failed to prevent myocardial necrosis but there was no recurrence of angina nor major left ventricular malfunction in the long term. This work suggests that early surgery after acute myocardial infarction may be a rescue procedure, with low risks and good long-term results.

Acute postinfarction septal rupture: long-term results.

From 1973 to 1989, 66 patients received early surgical repair for acute postinfarction ventricular septal rupture. Mean age was 64 +/- 7 years (range, 45 to 80 years). Ventricular septal rupture occurred soon after acute myocardial infarction (3.4 +/- 4 days), and the first medical treatment occurred 6.7 +/- 7 days after onset of acute myocardial infarction. Three patients had a previous myocardial infarction. The site of the rupture was anterior in 38 patients (57%) and posterior in 28 (43%). Forty-four patients (67%) were in shock at the time of admission. Intraaortic balloon pumping was used preoperatively in 28. Operation was performed at the time of maximal efficacy of medical treatment. The same technique was used in all cases. Associated procedures included coronary bypass grafting in 5 patients and valvar operation in 5. The patients have been carefully followed up for up to 16 years. Hospital mortality was 45% (30 patients) and was cardiac related or due to acute renal failure in 25 patients (83%). No correlation could be revealed between early death and age, sex, preoperative intraaortic balloon pumping, or year of operation. Location of the ventricular septal rupture (early mortality of 57% for posterior versus 37% for anterior ventricular septal rupture) and shock at the time of admission (52% versus 32%) showed a trend toward significance (0.08 less than or equal to p less than 0.10). Response to initial active therapy has a strong predictive value (mortality of 70% in unresponsive patients versus 14% in responders; p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

[Heart transplantation in acute myocardial infarction]. / La transplantation cardiaque dans l'infarctus du myocarde aigu.

Ten patients with cardiogenic shock after acute myocardial infarction were referred to the University Hospital Henri Mondor as candidates for cardiac transplantation. The period before transplantation was bridged by maximal pharmacological support including sympathomimetic and phosphodiesterase inhibitor inotropic agents and, in non-responders, by mechanical ventricular assist devices (1 case) or artificial hearts (2 cases). The 7 patients who improved with optimal pharmacological support alone had a good initial course. However, only two of these patients were finally transplanted, three died suddenly either in the intensive care unit or after withdrawal of intravenous drugs and hospital discharge. One patient remained well and after coronary bypass surgery, enjoys good quality life. One patient was found secondarily to be a poor candidate for transplantation and died shortly after. The outcome of 2 of the 3 patients who did not respond to pharmacological treatment and who required mechanical support was spectacularly good and enabled successful cardiac transplantation. Our experience underlines the numerous difficulties of different natures of cardiac transplantation in this indication, the value and risks of the new inotropic agents, and the real but limited role of heroic procedures such as the artificial heart.

Effects of sodium-nitroprusside and urapidil on gas exchange and ventilation-perfusion relationships in patients with congestive heart failure.

Vasodilators usually decrease arterial PO2 in patients with congestive heart failure (CHF) because of alteration in ventilation-perfusion (Va/Q) relationships. The effects of sodium nitroprusside (SNP) and urapidil (U), a new selective alpha 1-receptor antagonist, were investigated in seven patients with CHF. The distribution of ventilation and perfusion was examined using the multiple gas elimination technique. The haemodynamic responses to SNP and U were similar, cardiac index increasing by 25% with SNP and by 31% with U. Despite a similar increase of mixed venous oxygen tension, the arterial PO2 decreased from 11.3 +/- 0.8 to 9.6 +/- 0.6 kPa (p less than 0.01) with SNP but remained unchanged (11.0 +/- 0.9 vs 11.4 +/- 0.8 kPa, NS) with U. SNP and U both increased perfusion to lung units with Va/Q ratios of 0.1 or less with no change in shunt fraction. The fractional perfusion to total low Va/Q ratios (low Va/Q + shunt) was higher with SNP than with U (14.1 +/- 2.6 vs 9.5 +/- 2.3%, p less than 0.01). The results suggest that gas exchange and Va/Q relationships are altered less with U than with SNP in patients with CHF.

[Laser and arterial recanalization]. / Laser et désobstruction artérielle.

Interventional cardiorhythmology was born with the invention of electrical catheter ablation of the common atrioventricular bundle of His as a palliative treatment of supraventricular arrhythmias refractory to medicinal treatment. This method is now used as a curative treatment. In Wolff-Parkinson-White syndrome, all accessory pathways, whatever their location, can be destroyed with a very high success rate (96 p. 100) and very low morbidity and mortality rates. Reentrant nodal tachycardias can also be treated by catheter ablation with, however, a low risk of atrioventricular block which, for the moment, limits its indications. In intractable ventricular tachycardias, its indications will certainly be extended and its efficacy will increase since numerous recent studies have identified a limited, slow-conduction area (arrhythmogenic substrate) as being the real target for ablation. Other sources of energy are also used for the same purposes, including radiofrequency currents with results that are promising but vary according to the type of arrhythmia treated. Thus, interventional cardiorhythmology is progressively replacing surgery.