Respiratory syncytial virus-associated mortality in a healthy 3-year-old child: a case report.

BACKGROUND: Respiratory syncytial virus (RSV) is the most frequently identified pathogen in children with acute lower respiratory tract infection. Fatal cases have mainly been reported during the first 6 months of life or in the presence of comorbidity. CASE PRESENTATION: A 47-month-old girl was admitted to the pediatric intensive care unit following sudden cardiopulmonary arrest occurring at home. The electrocardiogram showed cardiac asystole, which was refractory to prolonged resuscitation efforts. Postmortem analyses detected RSV by polymerase chain reaction in an abundant, exudative pericardial effusion. Histopathological examination was consistent with viral myoepicarditis, including an inflammatory process affecting cardiac nerves and ganglia. Molecular analysis of sudden unexplained death genes identified a heterozygous mutation in myosin light chain 2, which was also found in two other healthy members of the family. Additional expert interpretation of the cardiac histology confirmed the absence of arrhythmogenic right ventricular dysplasia or hypertrophic cardiomyopathy. CONCLUSIONS: RSV-related sudden death in a normally developing child of this age is exceptional. This case highlights the risk of extrapulmonary manifestations associated with this infection, particularly arrhythmia induced by inflammatory phenomena affecting the cardiac autonomic nervous system. The role of the mutation in this context is uncertain, and it is therefore necessary to continue to assess how this pathogenic variant contributes to unexpected sudden death in childhood.

Outcomes after cryoablation vs. radiofrequency in patients with paroxysmal atrial fibrillation: impact of pulmonary veins anatomy.

AIMS: Pulmonary vein isolation is the mainstay of treatment in catheter ablation of paroxysmal atrial fibrillation (AF). Cryoballoon ablation has been introduced more recently than radiofrequency ablation, the standard technique in most centres. Pulmonary veins frequently display anatomical variants, which may compromise the results of cryoballoon ablation. We aimed to evaluate the mid-term outcomes of cryoballoon ablation in an unselected population with paroxysmal AF from an anatomical viewpoint. METHODS AND RESULTS: Consecutive patients with paroxysmal AF who underwent a first procedure of cryoballoon ablation or radiofrequency were enrolled in this single-centre study. All patients underwent systematic standardized follow-up. Comparisons between radiofrequency and cryoballoon ablation (Arctic Front™ or Arctic Front Advance™) were performed regarding safety and efficacy endpoints, according to pulmonary vein (PV) anatomical variants. A total of 687 patients were enrolled (376 radiofrequency and 311 cryoballoon ablation). Baseline characteristics and distribution of PV anatomical variants were generally similar in the groups. After a mean follow-up of 14 ± 8 months, there was no difference in the incidence of relapse (17.0% cryoballoon ablation vs. 14.1% radiofrequency, P = 0.25). We observed no interaction of PV anatomical variants on mid-term procedural success. CONCLUSION: Our findings suggest that mid-term outcomes of cryoballoon ablation for paroxysmal AF ablation are similar to those of radiofrequency, regardless of PV anatomy. The presence of anatomical variants of PVs should not discourage the referral of patients with paroxysmal AF for cryoballoon ablation.

Stereotactic magnetic resonance imaging-guided radiotherapy for intracardiac metastases: A case report.

Adrenocortical carcinoma is a malignant tumor with a poor prognosis and a frequent metastatic extension. In very rare cases, a cardiac metastatic disease may occur, and surgical resection is essential for its management. MR-guided stereotactic radiotherapy is an attractive radiotherapy modality for the treatment of mobile thoracic tumors, enabling the target to be monitored continuously during irradiation, while the dosimetric plan can be adapted daily if necessary. We report here the case of a patient with intracardiac metastasis secondary to malignant adrenocortical carcinoma, treated with magnetic resonance imaging-guided stereotactic radiotherapy.

[C-reactive protein (CRP) after revascularized STEMI: is CRP a prognostic factor?]. / Intérêt de la C-reactive protein (CRP) dans l'évaluation pronostique de l'infarctus du myocarde revascularisé

PURPOSE: During myocardial infarction (MI), numerous biomarkers increase, such as troponin (necrosis), BNP, and high sensibility C-reactive protein (hsCRP) (inflammation). The objectives of the study were to study kinetics of hsCRP after a revascularized MI, and correlations between hsCRP and clinical outcomes or biological markers, and prognostic value of CRP. PATIENTS AND METHODS: Fifty-two patients were admitted for STEMI (ST segment Elevation MI). Primary coronarography interventions (PCI) were performed for urgent reperfusion. Patients were included only in case of success (TIMI 3). Clinical examination was completed by a biological follow-up of BNP, troponin-I (before and after PCI, days 1, 2, 3, 6) and hsCRP (days 0, 1, 2, 3, 6). Clinical outcomes follow-up was performed during hospitalization, on the first month, and the sixth month. RESULTS: hsCRP increases during the first days (peak on day 3: 46.1mg/L), and decreases between the third and the seventh day. Clinical outcomes were correlated with CRP: door-to-balloon time, age, creatinin level on admission. During follow-up, there were clinical events in 13/49 (26%) of the patients. Among them, hsCRP on day 2 was higher (p < 0.0001), compared to other patients. Compared to other biological markers, hsCRP was correlated with BNP on days 2 and 3 (p = 0.008). CONCLUSION: hsCRP increases after revascularized STEMI, in accordance to the infarct size, in the first days. hsCRP is correlated with cardiovascular pronostic biomarkers. hsCRP could play an active role, and could be used as a pronostic biomarker after revascularized STEMI, which are usually considered as a low-risk population.

[Intra-cardiac lymphoma with right heart failure: a therapeutic emergency in two patients]. / Lymphome intracardiaque avec insuffisance cardiaque droite: à propos de deux cas.

We report the cases of two patients admitted to the Emergency Department with a clinical picture of right heart failure. An emergency echocardiograph suggested an intra-cardiac tumor which turned out to be a primary intra-cardiac lymphoma in one case, and a diffuse lymphoma principally localised in the heart in the other. Echocardiographic, CT and MRI investigations clarified the sites, as well as anatomical relations and extensions. Histology confirmed the diagnosis, and allowed classification of the lymphoma in order to decide on treatment. A PET scan performed in one patient illustrated the response to treatment. The respective significance of each of these investigations is discussed, in addition to the management. While transthoracic echocardiography remains the key element in the acute management, MRI and PET scans are being used more and more often for determining the character of these lesions, as well as for assisting with therapeutic decisions and for follow-up.

[Surgery of ventricular tachycardia in post-infarction left ventricular aneurysm]. / Chirurgie des tachycardies ventriculaires sur anévrismes ventriculaires gauches post-infarctus.

The treatment of post-infarction ventricular tachycardias with antiarrhythmic drug therapy, implantable automatic defibrillators, radiofrequency ablation, also includes different surgical procedures such as endocardial resection of the infarct scar, encircling endocardial ventriculotomy and endocardial cryoablation or thermoexclusion by laser. These procedures may be extensive or limited, guided or not by preoperative mapping. The aim of this review of the literature is to update our knowledge of these different surgical techniques and to define their indications.

[Ventricular tachycardia due to branch to branch re-entry]. / Tachycardies ventriculaires par rentrée de branche a branche.

Ventricular tachycardia due to branch to branch re-entry constitutes a rare clinical entity. This circuit is remarkable by the fact that it is made up of the branches or hemi-branches of the bundle of His bifurcation. They occur under specific conditions, with a combination of left ventricular dilatation and atrioventricular or intraventricular conduction defects. They are also very often found in Steinert's disease. A positive diagnosis can sometimes be difficult and relies on a variety of factors. Recording of the His potential shows His activity preceding each ventriculogram, and variations in spontaneous cycles between 2 ventriculograms preceded by variations between the 2 His potentials. Atrial capture without modification of the QRS is possible, but fusion excludes the diagnosis. Drug therapy is only slightly effective, and the best treatment is ablation of the right branch of the bundle of His, which stops the tachycardia definitively.

[Characterization of premature ventricular contraction initiating ventricular fibrillation]. / Caractéristiques morphologiques des extrasystoles ventriculaires initiatrices des fibrillations ventriculaires.

UNLABELLED: The aim of this study is to characterize the electrocardiographic features of premature ventricular contractions (PVC) from different anatomical region that trigger ventricular fibrillation (VF). METHODS AND RESULTS: 36 consecutives patients (20 males, 42+/-14 yrs) undergoing VF ablation from 7 centres were studied (22 with idiopathic VF, 4 associated with a long QT syndrome, 3 with Brugada syndrome, 4 with ischaemic cardiomyopathy and 3 associated with other substrate). Mapping of these PVC showed 2 different origins, which were then confirmed by ablation: right ventricular outflow tract (RVOT) (22%) and peripheral Purkinje network (81%). One patient had PVC from both origins (Brugada). RVOT PVC were frequent but had triggered only 5+/-5 episodes of VF for 26+/-33 months. Purkinje PVC were more likely to be present during electrical storm with 18+/-28 episodes of VF for 33+/-45 months. Right Purkinje PVC have a left bundle branch block with superior axis morphology whereas left Purkinje ones have a right bundle branch block. The axis of activation showed variation from inferior to superior depending on the area of origin from the Purkinje network and the exit site to the myocardium. However Purkinje PVC were characterized by short QRS duration (126+/-18 vs 145+/-13ms for RVOT PVC; p=0.05). In addition the coupling interval was significantly shorter compared to RVOT PVC (292+/-45 vs 358+/-37ms respectively; p=0.005). CONCLUSION: PVC initiating VF demonstrate specific electrocardiographic features that facilitate determination of their origin. Ablation of these typical PVC is feasible in order to reduce ICD shock.

ACE Inhibitor Delapril Prevents Ca(2+)-Dependent Blunting of IK1 and Ventricular Arrhythmia in Ischemic Heart Disease.

Angiotensin-converting enzyme inhibitors (ACE-I) improve clinical outcome in patients with myocardial infarction (MI) and chronic heart failure. We investigated potential anti-arrhythmic (AA) benefits in a mouse model of ischemic HF. We hypothesized that normalization of diastolic calcium (Ca(2+)) by ACE-I may prevent Ca(2+)-dependent reduction of inward rectifying K(+) current (IK1) and occurrence of arrhythmias after MI. Mice were randomly assigned to three groups: Sham, MI, and MI-D (6 weeks of treatment with ACE-I delapril started 24h after MI). Electrophysiological analyses showed that delapril attenuates MI-induced prolongations of electrocardiogram parameters (QRS complex, QT, QTc intervals) and conduction time from His bundle to ventricular activation. Delapril improved the sympatho-vagal balance (LF/HF) and reduced atrio-ventricular blocks and ventricular arrhythmia. Investigations in cardiomyocytes showed that delapril prevented the decrease of IK1 measured by patch-clamp technique. IK1 reduction was related to intracellular Ca(2+) overload. This reduction was not observed when intracellular free-Ca(2+) was maintained low. Conversely, increasing intracellular free-Ca(2+) in Sham following application of SERCA2a inhibitor thapsigargin reduced IK1. Thapsigargin had no effect in MI animals and abolished the benefits of delapril on IK1 in MI-D mice. Delapril prevented both the prolongation of action potential late repolarization and the depolarization of resting membrane potential, two phenomena known to trigger abnormal electrical activities, promoted by MI. In conclusion, early chronic therapy with delapril after MI prevented Ca(2+)-dependent reduction of IK1. This mechanism may significantly contribute to the antiarrhythmic benefits of ACE-I in patients at risk for sudden cardiac death.

Chronic bradykinin infusion and receptor blockade in angiotensin II hypertension in rats.

The influence of endogenous bradykinin(BK) on the control of arterial pressure and the development of cardiac hypertrophy was assessed in chronically angiotensin II(Ang II)-infused rats (200 ng. kg-1. min-1) through the effects of concomitant infusion of 3 doses of BK (15 ng. kg-1. d-1, 100 ng. kg-1. d-1 and 100 ng. kg-1. min-1 ie, 144 000 ng. kg-1. d-1) or BK-blockade by Hoe140 (300 microg. kg-1. d-1) for 10 days. In Ang II-infused rats, tail-cuff pressure increased from 124+/-3 to 174+/-6 mm Hg (P<0.001). The pressor effect of Ang II was not affected by simultaneous infusion of BK or Hoe140. At the end of the experiments, cardiac mass was higher in rats infused with Ang II alone (3.56+/-0.10 versus 2.89+/-0.05 mg/g in untreated controls, P<0.01) and the development of cardiac hypertrophy was not modified by administration of the 3 doses of BK or Hoe140. In addition, the fall in cardiac output associated with Ang II was prevented only by the moderate and high doses of BK, mainly through an increase in stroke volume and a decrease in total peripheral resistance. In the same way, the renal vasoconstrictor effect of Ang II was abolished by the medium and high dose of BK. Hoe140 did not affect cardiac output or renal blood flow in this model. No influence of BK or Hoe140 on the increase in albuminuria induced by Ang II was detected. In conclusion, exogenous BK may oppose the effect of Ang II on vascular tone, but it cannot prevent hypertension and target-organ damage associated with this experimental model of hypertension, even at a very high dose.

Sodium but not chloride ion modulates left ventricular hypertrophy in two-kidney, one clip hypertension.

OBJECTIVE: To assess the role of dietary sodium with or without chloride on the development of hypertension and left ventricular hypertrophy. METHODS AND RESULTS: Forty-nine male Sprague-Dawley rats with two-kidney, one clip hypertension were fed three different diets for 4 weeks after clipping: free access to sodium chloride, sodium citrate or sodium-free diet. Sham-operated rats were used as controls. The final conscious systolic arterial pressure was similar in all hypertensive groups, regardless of diet. A similar increase in left ventricular mass was observed in the rats on the sodium chloride and sodium citrate diets, whereas left ventricular hypertrophy was strikingly attenuated in the rats on the sodium-free diet. CONCLUSION: Dietary sodium restriction prevented the development of left ventricular hypertrophy without affecting consistently the final level of hypertension. Also, the anion associated with sodium had no influence on the level of arterial pressure and left ventricular mass when compared with rats maintained on sodium chloride. It is suggested that dietary sodium itself might be an important modulator of the left ventricular response to hypertension.

Large encircling cryoablation without mapping for ventricular tachycardia after anterior myocardial infarction: long-term outcome.

OBJECTIVE: Map-guided procedures have been the accepted standard for ventricular tachycardia surgery. However, promising results of visually guided resections without mapping have been reported. The goal of this study was to evaluate the efficacy of large encircling cryoablation without mapping for ventricular tachycardia after anterior myocardial infarction. METHODS: Between 1985 and 1996, this procedure, along with aneurysmectomy, was performed on 38 patients for malignant ventricular tachycardia. The mean interval between the operation and myocardial infarction was 59.2 months; 7 patients (18.4%) were operated on within 1 month of myocardial infarction. The mean patient age was 62.1 +/-7.3 years and the mean left ventricular ejection fraction was 29.0% +/-7.2%. RESULTS: Hospital mortality was 2.6% (1 patient). The electrical success rate based on postoperative electrophysiologic studies was 94.5%. Overall electrical success rate was 89.1%. Freedom from ventricular tachycardia was 77% (95% CI 61%-94%) at both 5 and 7 years. Freedom from sudden cardiac death was 91% (95% CI 80%-100%) at both 5 and 7 years, with overall actuarial survivals at 5 and 7 years of 63% (95% CI 47%-80%) and 42% (95% CI 22%-63%), respectively. The main cause of late death was congestive heart failure in 62.6% of these patients. CONCLUSIONS: One can achieve good results without intraoperative mapping in the treatment of patients with ventricular tachycardia after anterior myocardial infarction by using large encircling cryoablation.

Combined assessment of reflow and collateral blood flow by myocardial contrast echocardiography after acute reperfused myocardial infarction.

OBJECTIVE: To evaluate the combined assessment of reflow and collateral blood flow by myocardial contrast echocardiography after myocardial infarction. DESIGN: Myocardial contrast echocardiography was performed in patients with acute myocardial infarction shortly after successful coronary reperfusion (TIMI 3 patency) by direct angioplasty. Collateral flow was assessed before coronary angioplasty, and contrast reflow was evaluated 15 minutes after reperfusion. The presence of contractile reserve was assessed by low dose dobutamine echocardiography (5 to 15 micrograms/kg/min) at (mean (SD)) 3 (2) days after myocardial infarction. Recovery of segmental function (myocardial viability) was evaluated by resting echocardiography at a two month follow up. The study was prospective. PATIENTS: 35 consecutive patients referred for acute transmural myocardial infarction. RESULTS: Contrast reflow was observed in 20 patients (57%) and collateral flow in 14 (40%). Contrast reflow and collateral contrast flow were both correlated with reversible dysfunction on initial dobutamine echocardiography and at follow up (p < 0.05). The presence of reflow or collateral flow on myocardial contrast echocardiography was a highly sensitive (100%) but weakly specific (60%) indicator of segmental dysfunction recovery. Simultaneous presence of contrast reflow and collateral flow was more specific of reversible dysfunction than reflow alone (90% v 60%). CONCLUSIONS: Combined assessment of reflow and collateral blood flow enhanced the sensitivity of myocardial contrast echocardiography in predicting myocardial viability after acute, reperfused myocardial infarction. The simultaneous presence of reflow and collateral blood flow was highly specific of recovery of segmental dysfunction.

Left ventricular adaptation to hypertension and plasma renin activity.

Chronic pressure and volume overload result in morphologically and functionally distinct forms of myocardial hypertrophy. In essential hypertension, the respective effect of these factors on the morphology of the left ventricle remains unknown. In the present study, we hypothesised that activity of the renin angiotensin system (assessed by plasma renin activity) may be associated to the variability of the left ventricular adaptation to essential hypertension. To assess this relation, we categorised by echocardiography 333 never-treated hypertensive patients, according to values of left ventricular mass and relative wall thickness. Higher systolic and pulse arterial pressure was strongly associated with concentric left ventricular hypertrophy (27% of hypertensives). When compared to the normal left ventricle group, patients with eccentric left ventricular hypertrophy (15% of hypertensives) had a high cardiac index (5 +/- 1 vs 4 +/- 0.8 L/min/m2; P = 0.0001), a lower basal plasma renin activity (0.81 +/- 0.63 vs 1.45 +/- 1.3 ng/ml/h; P = 0.02) and similar mean values of left ventricular performance and glomerular filtration rate. A tendency for depressed myocardial contractility assessed by the midwall shortening/end-systolic stress was associated with concentric left ventricular remodelling and hypertrophy when compared to hypertensive with a normal left ventricle. In conclusion, at the early phase of essential hypertension, in patients without renal dysfunction, each anatomic pattern of cardiac adaptation to hypertension was associated with a distinct profile of haemodynamics, myocardial function and activity of the renin-angiotensin system. Journal of Human Hypertension (2000) 14, 181-188.

[Parasystole]. / Parasystolie.

Parasystole is usually an extrasystolic rhythm which can occur at every level, but particularly in the ventricle. It is admitted that the parasystolic focus is protected from the environing myocardium by an entry block but can manifest itself. Actually, a pure unidirectional block does not exist and the environing myocardium affects the parasystolic rhythm by an electrotonic current which modulates the output. A non-parasystolic complex which occurs prematurely in the parasystolic cycle delays it. Conversely it accelerates the cycle when it occurs late. By this fact, a parasystole pacing is possible and can lead to a fixed coupling. This arrhythmia is frequently unknown and can be experimentally, reproduced by a sucrose gap preparation.

[Diagnosis of narrow QRS complex tachycardias]. / Diagnostic des tachycardies à QRS fins.

Tachycardias with normal QRS complexes (less than 0.12 seconds) may have multiple origins which may be classified in 4 groups: sinusal, atrioventricular nodal, atrioventricular junctional and finally, some ventricular tachycardias arising from near the conduction pathways. The electrocardiographic diagnosis requires analysis of the QRS complexes to detect an eventual irregularity which would suggest atrial fibrillation. When the tachycardia is regular, analysis of the P waves is fundamental (position in the ventricular cycle and morphology). The relationship of the P waves and the QRS complexes enables identification of those forms independent of the AV node and some rare types of tachycardia. Finally, the response to vagal stimulation is essential whether the tachycardia stops, slows down or persists unchanged.

[The electrocardiogram of atrioventricular blocks]. / Electrocardiogramme des blocs auriculo-ventriculaires.

Atrioventricular block (AVB) is defined as delay or absence of transmission of one or more atrial excitations to the ventricle. Physiological functional block protects the ventricle against very rapid atrial rhythms. Organic blocks may be transient, due to an acute regressive condition, or chronic, in which case they fall into two groups--permanent blocks or paroxysmal and generally rate-dependant blocks. The blocks are classified in three categories according to whether the atrial activation is delayed, conducted intermittently or not at all. The site of AVB may be determined by His bundle recordings but it may also be deduced from the surface ECG recording. Fundamental studies have questioned the reality of Rosenbaum's phase 3 and 4 blocks and suggest abnormalities of excitability in pathological zones.

[Influence of angiotensin I on angiogenesis in vitro in the rat]. / Influence de l'angiotensine II sur les capacités angiogéniques d'explants vasculaires de rat.

The regulation of angiogenesis involves complex interactions. The aim of our study was to assess the influence of angiotensin II (ANG II) on different vascular beds in rat. Aortic, renal and mesenteric rings from 10 male Sprague-Dawley rats were cultured using a three-dimensional culture system consisting of rat type I collagen lattice. We assessed the influence of different ANG II concentrations (10(-7) et 10(-9) mol/L) on these rings as well as the effect of AT1 blockade by losartan (10(-7 mol/L). ANG II inhibited angiogenesis at 10(-7) mol/L on renal artery. However, these was a angiogenic effect at 10(-9) mol/L on the mesenteric artery. Every time losartan prevented the effect of ANG II in any kind of vessel rings. No significant effect on ANG II was found on aortic rings but coadministration of losartan induced a dramatic decrease in the number of capillary sprouts. In conclusion, ANG II seems to be deeply involved in angiogenesis. However, its effect depends on the concentration of ANG II and the type of vessel. ANG II appears to be angiogenic on mesenteric arteries via an AT1 receptor effect and mostly anti-angiogenic on the renal arteries with possible involvement of AT2 receptors.

[Bouveret's tachycardia]. / Tachycardies de Bouveret.

In 1889, in an age preceding the invention of the electrocardiogram, a physician working in the hospitals of Lyon published a remarkable paper on essential paroxysmal tachycardia, of which Bristowe in England and Huppert in Germany had already spoken. The study described 12 cases (including 3 personal cases) of essential paroxysmal tachycardia and 6 secondary tachycardias. They were not all benign, there being 4 deaths out of the 12 cases. From this period on, the term "Bouveret's tachycardia" has been used in France and, with the advances in rhythmology, some have assimilated it to paroxysmal nodal tachycardia. In fact, many forms of paroxysmal essential tachycardia have been recognised at atrial (nodal tachycardia, accessory pathway tachycardia, idiopathic atrial flutter and fibrillation) and ventricular levels (benign or ventricular Bouveret's tachycardia). This is an occasion to review the variety of clinical medicine in the accuracy of a rhythmological diagnosis without forgetting that the electrocardiogram is essential when the recordings are analysable. The term of Bouveret's tachycardia should be retained but, before electrocardiographic analysis, it englobes all paroxysmal tachycardia occurring in healthy hearts, and not only paroxysmal nodal tachycardia.

[Role of dietary sodium in experimental renovascular hypertension]. / Rôle du sodium alimentaire dans l'hypertension rénovasculaire expérimentale.

In order to assess the role of dietary sodium with or without chloride on the development of 2 kidney, 1 clip renovascular hypertension, 49 male Sprague-Dawley rats were fed 3 different diets for 4 weeks after clipping: ad libitum sodium chloride, sodium citrate or sodium-free diet. Sham operated rats were used as control. The final conscious systolic arterial pressure was similar in all hypertensive groups regardless of diet. No change in cardiac index occurred in clipped animals whereas total peripheral resistance raised to a similar extent. In conclusion, sodium restriction did not prevent hypertension. In addition, the anion linked to sodium had no influence on the level of arterial pressure.