Neutrophilic infiltration in organ-on-a-chip model of tissue inflammation

The multiphasic etiology of tissue inflammation and the fundamental immunological differences between species render inflammatory pathologies difficult to recapitulate in animal models, and account for the paucity of therapies that are successfully translated from rodents to humans. Here, we present a human-relevant organ-on-a-chip platform for experimental inflammatory diseases. We created an immunocompetent in vitro gut model by incorporating intestinal epithelial and immune cells into microfluidic chambers that permit cell movement across an extracellular matrix (ECM) and fluidic channels. This is the first model that integrates a mucosal barrier, a three-dimensional ECM, resident and infiltrating immune cells, and simulates a functional crosstalk that ultimately triggers cellular processes representative of inflammation. Under homeostatic conditions, enterocytes form a tight epithelium and subepithelial macrophages are non-activated. Introduction of pro-inflammatory mediators triggers macrophage activation and inflammation-induced intestinal barrier leakiness. Neutrophils in a parallel, matrix-separated non-epithelial channel are attracted by such a pro-inflammatory microenvironment and migrate through the extracellular matrix, further exacerbating tissue inflammation and damage. With this model, we provide the foundations to recapitulate and investigate the onset of tissue inflammation in a controlled, human-relevant system.

A randomized, double-blind, placebo-controlled trial on the efficacy of tranexamic acid combined with rivaroxaban thromboprophylaxis in reducing blood loss after primary cementless total hip arthroplasty

AIMS

Cementless primary total hip arthroplasty (THA) is associated with risks of bleeding and thromboembolism. Anticoagulants are effective as venous thromboprophylaxis, but with an increased risk of bleeding. Tranexamic acid (TXA) is an efficient antifibrinolytic agent, but the mode and timing of its administration remain controversial. This study aimed to determine whether two intravenous (IV) TXA regimens (a three-hour two-dose (short-TXA) and 11-hour four-dose (long-TXA)) were more effective than placebo in reducing perioperative real blood loss (RBL, between baseline and day 3 postoperatively) in patients undergoing THA who receive rivaroxaban as thromboprophylaxis. The secondary aim was to assess the non-inferiority of the reduction of blood loss of the short protocol versus the long protocol.

PATIENTS AND METHODS

A multicentre, prospective, randomized, double-blind, placebo-controlled trial was undertaken involving 229 patients undergoing primary cementless THA using a posterior approach, whose extended rivaroxaban thromboprophylaxis started on the day of surgery. There were 98 male and 131 female patients, with a mean age of 65.5 years (32 to 91). The primary outcome, perioperative RBL, was evaluated at 72 hours postoperatively. The efficacy of short- and long-TXA protocols in the reduction of perioperative RBL was compared with a placebo group.

RESULTS

TXA significantly reduced perioperative blood loss compared with placebo (p < 0.001); the mean differences were 525.3 ml (short-TXA vs placebo) and 550.1 ml (long-TXA vs placebo). No venous or arterial thromboembolic complications were reported. The upper boundary of the 95% confidence interval, when comparing short and long protocols, was below the pre-specified margin of non-inferiority (p = 0.027).

CONCLUSION

In patients undergoing primary cementless THA, using a posterior approach, who are treated with rivaroxaban for thromboembolic prophylaxis, short- and long-TXA IV protocols are significantly more effective than placebo in reducing perioperative RBL, without any thromboembolic complications. Non-inferiority of a short- versus a long-TXA protocol in reducing perioperative RBL was supported in a secondary analysis.

GalNAc Conjugation Attenuates the Cytotoxicity of Antisense Oligonucleotide Drugs in Renal Tubular Cells

Targeted delivery of antisense oligonucleotide (AON) drugs is a promising strategy to increase their concentration in the desired tissues and cell types while reducing access to other organs. Conjugation of AONs to N-acetylgalactosamine (GalNAc) has been shown to efficiently shift their biodistribution toward the liver via high-affinity binding to the asialoglycoprotein receptor (ASGPR) expressed at the surface of hepatocytes. Nevertheless, GalNAc conjugation does not prevent accumulation of AONs in the kidney cortex, and GalNAc-conjugated AONs might cause kidney toxicities, for example, under conditions of ASGPR saturation. Here, we investigated the nephrotoxicity potential of GalNAc-conjugated AONs by in vitro profiling of AON libraries in renal proximal tubule epithelial cells (PTECs) and in vivo testing of selected candidates. Whereas GalNAc-conjugated AONs appeared generally innocuous to PTECs, some caused mild-to-moderate nephrotoxicity in rats. Interestingly, the in vivo kidney liabilities could be recapitulated in vitro by treating PTECs with the unconjugated (or naked) parental AONs. An in vitro mechanistic study revealed that GalNAc conjugation attenuated AON-induced renal cell toxicity despite intracellular accumulation similar to that of naked AONs and independent of target knockdown. Overall, our in vitro findings reveal ASGPR-independent properties of GalNAc AONs that confer a favorable safety profile at the cellular level, which may variably translate in vivo due to catabolic transformation of circulating AONs.

Dramatic Increase in Incidence of Ulcerative Colitis and Crohn's Disease (1988-2011): A Population-Based Study of French Adolescents

OBJECTIVES

Few data are available to describe the changes in incidence of pediatric-onset inflammatory bowel disease (IBD). The aim of this study was to describe changes in incidence and phenotypic presentation of pediatric-onset IBD in northern France during a 24-year period.

METHODS

Pediatric-onset IBD (<17 years) was issued from a population-based IBD study in France between 1988 and 2011. Age groups and digestive location were defined according to the Paris classification.

RESULTS

1,350 incident cases were recorded (8.3% of all IBD) including 990 Crohn's disease (CD), 326 ulcerative colitis (UC) and 34 IBD unclassified (IBDU). Median age at diagnosis was similar in CD (14.4 years (Q1=11.8-Q3=16.0)) and UC (14.0 years (11.0-16.0)) and did not change over time. There were significantly more males with CD (females/males=0.82) than UC (females/males=1.25) (P=0.0042). Median time between onset of symptoms and IBD diagnosis was consistently 3 months (1-6). Mean incidence was 4.4/10⁵ for IBD overall (3.2 for CD, 1.1 for UC and 0.1 for IBDU). From 1988-1990 to 2009-2011, a dramatic increase in incidences of both CD and UC were observed in adolescents (10-16 years): for CD from 4.2 to 9.5/10⁵ (+126%; P<0.001) and for UC, from 1.6 to 4.1/10⁵ (+156%; P<0.001). No modification in age or location at diagnosis was observed in either CD or UC.

CONCLUSIONS

In this population-based study, CD and UC incidences increased dramatically in adolescents across a 24-year span, suggesting that one or more strong environmental factors may predispose this population to IBD.

Hawkins' type-II talar fracture with subtalar dislocation: A very unusual combination

We report the unusual case of a 16-year-old young man who sustained a rare association of a Hawkins' type-II talar neck fracture with a complete medial subtalar dislocation (Hawkins type-IIB) that occurred as an isolated injury after indirect trauma during a soccer game. Following closed reduction of the subtalar dislocation, standard radiographs and computed tomography (CT) demonstrated a comminuted fracture of the talus involving the base of the talar neck. Open reduction was performed and the fracture was stabilized by ORIF. At 1-year follow-up, functional and radiographic outcomes were graded as excellent, with no radiographic evidence of talar osteonecrosis.

White-to-brown metabolic conversion of human adipocytes by JAK inhibition

The rising incidence of obesity and related disorders such as diabetes and heart disease has focused considerable attention on the discovery of new therapeutics. One promising approach has been to increase the number or activity of brown-like adipocytes in white adipose depots, as this has been shown to prevent diet-induced obesity and reduce the incidence and severity of type 2 diabetes. Thus, the conversion of fat-storing cells into metabolically active thermogenic cells has become an appealing therapeutic strategy to combat obesity. Here, we report a screening platform for the identification of small molecules capable of promoting a white-to-brown metabolic conversion in human adipocytes. We identified two inhibitors of Janus kinase (JAK) activity with no precedent in adipose tissue biology that stably confer brown-like metabolic activity to white adipocytes. Importantly, these metabolically converted adipocytes exhibit elevated UCP1 expression and increased mitochondrial activity. We further found that repression of interferon signalling and activation of hedgehog signalling in JAK-inactivated adipocytes contributes to the metabolic conversion observed in these cells. Our findings highlight a previously unknown role for the JAK-STAT pathway in the control of adipocyte function and establish a platform to identify compounds for the treatment of obesity.

Disease modeling and phenotypic drug screening for diabetic cardiomyopathy using human induced pluripotent stem cells

Diabetic cardiomyopathy is a complication of type 2 diabetes, with known contributions of lifestyle and genetics. We develop environmentally and genetically driven in vitro models of the condition using human-induced-pluripotent-stem-cell-derived cardiomyocytes. First, we mimic diabetic clinical chemistry to induce a phenotypic surrogate of diabetic cardiomyopathy, observing structural and functional disarray. Next, we consider genetic effects by deriving cardiomyocytes from two diabetic patients with variable disease progression. The cardiomyopathic phenotype is recapitulated in the patient-specific cells basally, with a severity dependent on their original clinical status. These models are incorporated into successive levels of a screening platform, identifying drugs that preserve cardiomyocyte phenotype in vitro during diabetic stress. In this work, we present a patient-specific induced pluripotent stem cell (iPSC) model of a complex metabolic condition, showing the power of this technique for discovery and testing of therapeutic strategies for a disease with ever-increasing clinical significance.

The effect of collateral ligament release on ankle dorsiflexion: an anatomical study

BACKGROUND

Ankle stiffness is a common complication after ankle fracture, reconstructive surgery or total ankle replacement, and the usual limitation is in dorsiflexion. There are few articles in the literature concerning this frequent problem, and furthermore they are not recent and tend to be controversial. The purpose of this anatomical study was to evaluate and quantify the effect of ankle collateral ligament release on dorsiflexion, specifically the amount of increase in ankle dorsiflexion following section of the two ligaments most often implicated in ankle stiffness: the deep posterior tibiotalar ligament (dPTTaL, or posterior deep deltoid) and the posterior talofibular ligament (PTaFL).

METHODS

We dissected 18 adult fresh cadaveric ankle joints, and with an electronic goniometer combined with an electronic dynamometer measured their mobility in dorsiflexion before and after transection of each ligament separately, and the two ligaments combined.

RESULTS

The results showed a significant difference between the two groups of ankles with section of the dPTTaL resulting in a greater increase in ankle dorsiflexion than section of the PTaFL (mean 7.45° vs. 3.5°, respectively; p<0.001). Combined section of both ligaments improved the gain in ankle dorsiflexion more than isolated section of each ligament, but was not statistically significant (p=0.88).

CONCLUSION

If after gastrocnemius recession or Achilles tendon lengthening persistent restriction remains in ankle dorsiflexion, the results of our study demonstrate that the next step should be release of the dPTTaL.

[Does the thumb have two phalanges or three? Development of ideas since Aristotle]

Many controversies mark the long road of the history of anatomy. The hand is not exempt of them. Even Galen's clear thinking, founded on the strict determinism between the structure of an organ and its function, and based on animal dissection, was criticized. In view of the structural complexity of the hand, we will limit our study to one of the most symptomatic conceptual disagreements: whether the human thumb has two or three phalanges, according to whether we include the first metacarpus, or if the thumb's first phalanx is considered as the initial element. According to the latter theory, there is a missing element in the first digital row, and this missing element is the metacarpus. This theory is ancient and its evolution throughout history is discussed in our study. Finally, we explain the origin and bases of the reasoning that led us to suggest the word 'metaphalanx' to designate the first metacarpus.

Rotational femoral osteotomies using an endomedullary saw

INTRODUCTION

The goal of this retrospective study is to analyze a series of ten patients (11 osteotomies) who underwent closed femoral rotational osteotomy using an endomedullary saw; stabilization was achieved by a locked centromedullary nail. We report the indications, technical aspects, clinical and radiological results as well as intercurrent complications with this surgical technique.

HYPOTHESIS

Femoral endomedullary osteotomy is a safe procedure to correct malrotations.

PATIENTS AND METHODS

Eleven femoral rotational osteotomies using an endomedullary saw were performed on ten patients, between January 1999 and July 2007. The indications were post-traumatic rotational malunions or congenital rotational deformities. The angular deformity averaged 33.5 degrees (24 degrees -52 degrees ). They were divided into internal rotation (ten cases) or external rotation (one case). One patient required a bilateral rotational osteotomy because of a congenital femoral malrotation combined to bilateral trochlear dysplasia. Rotational correction was, in two patients, simultaneously associated with a closed lengthening osteotomy. Clinical and radiological follow-up averaged 4 years and 9 months (26-104 months). The angular corrections obtained by these rotation osteotomies were calculated by CAT scans.

RESULTS

Ten out of eleven osteotomies allowed a correction within a 4 degrees range in relation to the physiological femoral neck anteversion values (or to the contralateral side in the case of a healthy opposite lower extremity). There was no bone, joint, skin, or soft tissues infection, no pseudoarthrosis and no delayed outgrowth. We observed a transient neurological complication in the area of the pudendal nerve, during a combined rotational-lengthening osteotomy, as well as a bilateral femoral fracture during the bilateral rotational osteotomy. In all patients, consolidation occurred within a 3- to 5-month delay. The subjective results showed that eight out of nine patients (one was lost to follow-up) were satisfied or very satisfied with their operation, their functional recovery and the aesthetic aspects of their scars.

DISCUSSION

Closed rotational osteotomies in adults represent a reliable, effective, safe and reproducible procedure for the correction of femoral torsion problems, whether they are post-traumatic or congenital. These results can be obtained only by respecting the indications and by applying a rigorously planned technique, including expertise in centromedullary nailing.

LEVEL OF EVIDENCE

Level IV, retrospective therapeutic study.

[Septic arthritis after arthroscopic cruciate ligament reconstruction: in vitro comparison of the behavior of two types of interference screws towards the Staphylococcus aureus adherence]

PURPOSE OF THE STUDY

We report the results of an experimental study designed to investigate the behaviour of two types of interference screws (bioabsorbable versus titanium) in a context of Staphylococcus aureus infection. The main objective was to study one of the possible sources of failure for the treatment of acute arthritis of the knee after arthroscopic reconstruction of the cruciate ligament.

MATERIAL AND METHODS

We used six interference screws made of titanium and six bioabsorbable screws (PLLA-PDLLA). All screws measured 9mmx25mm, were cannulized and sterilized. These screws were submitted to a protocol elaborated in cooperation with the bacteriologists. After contamination with a strain of S. aureus, the screws were washed four times in saline solution to eliminate germs adsorbed in the aqueous phase. The last step was trypsination to detach germs remaining fixed onto the screws and contained in the biofilms of glycocalix. A germ count was made after each step. For each screw, we determined the difference (Delta) corresponding to the number of germs really adherent to the screw. Mann-Whitney analysis was performed.

RESULTS

On average, the germ count in the aqueous phase was 0.0855.10(5)/ml for the titanium screw versus 0.223.10(5)/ml for the bioabsorbable screw. The mean count of germs fixed in the biofilm (mean Delta) was 17.695+/-3.88.10(5) for the titanium screw and 45.86+/-3.61.10(5) for the bioabsorbable screw. The difference was statistically significant (p=0.0039).

DISCUSSION

Our experimental results support the efficacy of abundant arthroscopic lavage in a context of infection, confirming the results of very recent studies. However, irrespective of the type of material used, bioabsorbable screws are more prone to persistent microbial adherence than titanium screws. It is hypothesized that the hydrophilic, more porous microstructure of bioabsorbable screws favors bacterial adherence. In practice, this implies that arthroscopic washout must be as abundant and as complete as possible, yet may not be sufficient to clean the entire surface of potentially contaminated screw positioned deep in a bony tunnel.

[Ischemic eosinophilic granuloma and pulmonary histiocytosis with a regressive course]

Langerhans' histiocytosis or histiocytosis X is a rare intrinsically benign disease producing a destructive tumor with a variable clinical presentation and an often unpredictable clinical course. Focal forms such as eosinophilic granuloma of the bone only require minimal care but the gravity of multisystem forms causing organic dysfunction sometimes require aggressive chemotherapy. Bone involvement is generally observed in children mostly boys. Both sporadic and chronic forms are noted. We report a case observed in a 17-year-old adolescent who presented an exceptional association of bony destruction of the pelvis with extended asymptomatic pulmonary involvement. The lung disease led to the initial diagnosis and optimal surgical, pathological and radiological management.

[++Scintimammography: a new imaging technique for diagnosis and follow-up of breast cancer]

99m Tc MiBi has emerged as a new imaging technique for primary breast carcinomas. The aim of this study was to analyze the diagnostic performance and the additional information provided by scintimammography (SMN). Two hundred and forty consecutive women referred to surgery for abnormalities breast or suspicious breast cancer were scanned before surgery. Sensitivity and specificity were respectively 92% and 53%. PPV: 77.5% and PVN: 79.3%. All false negative scans occurred in cancers 1 cm. SMN detected multiple foci of uptake in the same breast in 13%, that were all confirmed to be multifocal disease and histology. Controlateral focal uptake was also detected; at this time 5/27 are confirmed to be bilateral breast neoplasms; 22 patients are in follow-up. SMN is reliable in the diagnosis of breast cancer and also with difficult cases of mammography. Moreover, SMN provides additional qualitative information in 19.6% of breast carcinomas, such as chest wall infiltration, multifocal or bilateral breast cancer.

[Insidious growth of peritoneal cysts several years after pelvic surgery. Ultrasonographic and x-ray computed tomographic aspects]

INTRODUCTION

The aim of the present study is to call the radiologist's attention to peritoneal cysts (PC) when making the diagnosis of cystic masses in patients with a history of long-standing abdominal surgery.

MATERIAL AND METHODS

Four cases of histologically proven peritoneal cysts, discovered 2 to 21 years after abdominal surgery were studied with ultrasonography (US) and computed tomography (CT). The symptoms leading to the diagnosis of PC included abdominal pain, discomfort and palpable mass.

RESULTS

On US and CT, the lesion of inflammatory origin appeared as a flaccid, septated and thin-walled cystic mass often mistaken for an ovarian lesion. Positive diagnosis of PC can be achieved at pathology examination by the identification of a mesothelial layer on the inner surface of the cyst.

CONCLUSION

CT or US images showing a flaccid multiseptated thin-walled cystic mass in a patient who has a history of previous abdominal surgery should draw the radiologist's attention to the diagnosis of PC among other cystic tumors.

Intrapulmonary artery coiling of a permanent pacing lead

Intrapulmonary artery displacement of a permanent ventricular lead is reported to be a severe form of lead coiling and is attributed to the failure of the fixation procedure. The lead instability indicated a need for surgical correction.

[Percutaneous venoplasty for the implantation of a dual-chamber cardiac pacemaker]

During reoperation for pacemaker implantation, venous catheterisation of the homolateral subclavian vein encountered obstruction at the brachiocephalic vein. Balloon angioplasty of the severe brachiocephalic stenosis was performed via the femoral vein. After repeat subclavian venous catheterisation two new pacing wires could be introduced without difficulty followed by active fixation in the atrium and passive fixation in the ventricular apex. The initial ventricular pacing wire was isolated and respected. The femoral vein approach gave simple and direct access to the site of dilatation at a distance to the operative field which was shielded from an infectious risk. The technique and results of percutaneous venous recanalisation have not been extensively analysed during reoperation for cardiac pacing. In chronic cardiac pacing, the success of homolateral operation despite venous occlusion or stenosis, ensures preservation of the venous capital.

[Comparison of the efficacy of 2 delayed-action preparations of hydroquinidine and quinidine in the prevention of pacing induced ventricular tachycardia]

The effects of two antiarrhythmic agents, hydroquinidine and quinidine on the prevention of pacing induced sustained ventricular tachycardia (VT) were studied in 14 patients. The underlying cardiac disease was old myocardial infarction (12 patients) or dilated cardiomyopathy (2 patients). Sustained monomorphic VT was induced in 14 patients during the initial electrophysiological study performed at least 48 hours after withdrawal of all antiarrhythmic therapy. The same stimulation protocol including 3 extrastimuli (S2 S3 S4) and 2 paced cycles (600 ms and 400 ms) was repeated at least 48 hours after the administration of 600 mg (2 gelules) per 24 hours of hydroquinidine or 1100 mg of quinidine arabogalactane sulphate, 3 to 4 hours after the last dose. This was an open, randomised, crossed over trial. Irrespective of the result observed with the first antiarrhythmic, used in an order attributed by a randomised table, the other antiarrhythmic was tested. Plasma concentrations were measured during the programmed stimulation test for both drugs. Induced VT was prevented by the two antiarrhythmics in 4 patients (28%). In one patient, VT was prevented by hydroquinidine but not by the quinidine compound, resulting in a prevention rate of 35% for the hydroquinidine. On the other hand, the quinidine compound was a total success in one patient in whom only a partial success was observed with hydroquinidine. VT remained inducible with both antiarrhythmics in 9 patients (64%).(ABSTRACT TRUNCATED AT 250 WORDS)

[Comparison of hospital prevalence of rheumatic heart diseases and acute rheumatic arthritis in France and Africa]

This study reports the results of a multicentre enquiry performed in France in 1990 which included 41,242 adults hospitalised in Cardiology Units, 33,907 children hospitalised in Pediatric departments and 8,868 soldiers. A comparative enquiry was also carried out in North Africa (Tunis) and West Africa (Abidjan, Ouagadougou). The results of the French arm of the enquiry showed that rheumatic heart disease (RHD) has become very rare in adults (3.1% of all cardiac disease) and that it tends to occur in older subjects (average 54.4 years of age). There is practically no RHD in young adults. This decreased prevalence of RHD is confirmed in children in whom this diagnosis represents only 0.04% of cases of all cardiac disease--of which 87.5% are of extra-European origin. In contrast, there is a high frequency of RHD in Tunisia (29.3%) and West Africa (13.2% in Abidjan and 13% in Ouagadougou). The disease remains active as is shown by the age of affected adults in Africa (average 21 and 27 years of age). The results also show a reduction to a very low prevalence of acute rheumatic fever in French pediatric departments (0.005%). The authors discuss the reasons for the persistence of endemic infection in Africa: virulence of the streptococcus, predisposing factors (HLA group?), geographic factors and, above all, socioeconomic factors and difficulties in obtaining treatment and prophylaxis. A movement of international cooperation is suggested in order to combat RHD in Africa, especially with regards to its prevention in childhood.(ABSTRACT TRUNCATED AT 250 WORDS)

[Comparative effects of anti-arrhythmia agents on ventricular refractory period and prevention of ventricular tachycardia induced by stimulation]

The efficacy of antiarrhythmic drugs is attributed to their actions on the refractory periods or conduction velocity in the reentry circuit. The aim of this study was to determine the relationship between these factors and the prevention of electrically inducible ventricular tachycardia (VT). Twenty-seven patients with sustained monomorphic postinfarction VT underwent programmed stimulation under basal conditions and after administration of oral Class I antiarrhythmic drugs. The protocol of stimulation consisted of delivering one to three extrastimuli to the right ventricular apex on two basic cycle lengths. Sustained VT was induced in all patients. After the same protocol under antiarrhythmic therapy (1 to 5 tests, average 2.9 +/- 1) sustained VT could not be induced in 12 patients (44%). The effective right ventricular refractory period was significantly increased in patients without inducible VT under treatment (247 +/- 18 versus 302 +/- 26 ms). The increase in the right ventricular effective refractory period in patients with persistence of inducible VT was much less (from 270 +/- 28 to 287 +/- 30 ms). In all patients in whom several antiarrhythmic drugs were tested the right ventricular effective refractory period was higher when the treatment was judged to be effective (299 +/- 27 ms) than ineffective (272 +/- 27, p < 0.02). The prevention of inducible VT by class I antiarrhythmic agents seems therefore to be related to their effect on the ventricular refractory period.

[Oral propranolol in Wolff-Parkinson-White syndrome. Electrophysiological data]

The effects of oral propranolol were studied in 24 patients with the WPW syndrome. The average daily dose of propranolol was 130 +/- 24 mg administered in 3 doses over a period of 48 to 72 hours. Endocavitary electrophysiological study was performed 2 to 4 hours after the last dose. The effective anterograde refractory periods (EARP) of the accessory and normal pathways were measured before and after propranolol (and, in both studies, before and after isoproterenol). The EARP of the accessory pathway was not affected by the propranolol. However, in the 9 patients in whom its value was less than 270 ms, it increased significantly (p = 0.01). The EARP of the accessory pathway measured after administration of isoproterenol increased significantly in all patients with oral propranolol (p = 0.001). Sustained reciprocating tachycardia could be induced in 19 patients and non-sustained reciprocating tachycardia in 5 other patients during base line electrophysiological study. Oral propranolol prevented the induction of the tachycardias in 18 patients (75%), even after isoproterenol. The shortest R-R interval between two pre-excited complexes in atrial fibrillation increased after propranolol (283 +/- 45 to 343 +/- 95 ms). These results show that oral propranolol increases the EARP of the accessory pathway and the shortest R-R interval between two pre-excited complexes in atrial fibrillation in patients with short anterograde refractory periods of their accessory pathways, and is effective in preventing reciprocating tachycardia. Oral propranolol may be useful and can be used safely in patients with the Wolff-Parkinson-White syndrome.

[Value of systematic preventive antibiotherapy in cardiac pacemaker implantation]

The aim of this study was to assess the usefulness of prophylactic antibiotics during insertion of a cardiac pacemaker, in order to avoid infection of exteriorisation of infectious origin. The study involved two groups. One hundred and eight patients made up group I, a control group without the use of prophylactic antibiotics. Group II consisted of 101 patients who were given an intravenous injection of 1 or 2 g of oxacillin before surgery, followed up by four days of oral oxacillin (3 g per day). Serum oxacillin levels at the end of the procedure were 0.37 +/- 0.09 mcg/ml, falling within the range of minimum inhibitory concentrations of methicillin-sensitive staphylococci. In the patients of the control group, followed up for 1 to 36 months (mean 12 +/- 11 months), during the first 2 months there were 2 infections, 4 exteriorisations and one cutaneous erosion over the pacemaker. In addition, one exteriorisation and one infection occurred at 17 and 29 months respectively. In patients with exteriorisation of their pacemaker device, there was nothing to suggest an infection and bacteriological specimens were sterile. No obvious infections nor any cutaneous complications occurred in the patients of group II, with prophylactic antibiotics, followed up for 1 to 21 months (mean 6 +/- 5 months). In conclusion, anti-staphylococcal antibiotic treatment appears not only to be capable of avoiding cardiac pacemaker infections but also of preventing exteriorisation of the pacemaker device, which may be linked to hidden infections. A randomised study is nevertheless necessary to confirm this hypothesis.

[Coronary angioplasty in patients aged 70 and over. Immediate results and later outcome]

One hundred and ninety one consecutive patients over 70 years of age (127 men and 64 women, average age 75.6 years) underwent percutaneous transluminal coronary angioplasty (PTCA) between January 1986 and February 1989. One hundred and sixty patients had severe angina (20 Class III and 140 Class IV), 72 patients had previous myocardial infarction, 36 of which were recent (less than 1 month), and 6 patients had previously undergone coronary bypass surgery. The coronary lesions affected one vessel in 67 patients and more than one vessel in 124 patients. The left ventricular ejection fraction was less than 50% in 15 patients. Angioplasty was attempted on 245 lesions (228 stenoses and 17 occlusions): 1 lesion in 141 patients, 2 lesions in 46 patients, 3 lesions in 4 patients, with a primary success rate of 81% in stenotic and 41% in occluded arteries. There were 9 deaths (4.7%) 6 of which occurred in patients with multivessel disease and unstable angina; there were 6 Q-wave infarctions (3.1%), 8 non Q-wave infarctions (4.2%) and 3 emergency coronary bypass operations (1.6%). The first 123 patients of this series were followed up for an average of 18.8 months (7 to 37 months). Follow-up of the 100 patients successfully dilated (4 lost to follow-up) showed that 55 remained improved (53 asymptomatic), 25 had recurrent angina after the initial improvement due to restenosis in 19, progression of coronary athero-sclerosis in 3, restenosis and an evolution of coronary atherosclerosis in 1 and a lesion which had been neglected in 2 cases.(ABSTRACT TRUNCATED AT 250 WORDS)

[Complex ventricular extrasystole. Value of programmed electric stimulation for evaluating the risk of sudden death]

A prospective study was carried out from May 1984 to July 1987 to determine the prognostic value of the results of programmed electrical stimulation (PES) in patients with complex ventricular ectopy. The study population comprised 118 patients, 80 with and 38 without apparent underlying cardiac disease. The PES consisted in at most 3 extrastimuli delivered to the right ventricular apex during 2 imposed basal rhythms. Two groups of patients were identified: Group I (n = 35; 29.6%) in which a significant ventricular arrhythmia was induced (sustained ventricular tachycardia (11 cases), non-sustained VT (21 cases) and ventricular fibrillation (3 cases); and Group II (n = 83; 70.3%) in which no significant arrhythmia could be induced. During follow-up (average 28.7 +/- 11.7 months, range 6 to 48 months) there were 10 cardiac deaths, 8 of which occurred suddenly. Sudden death only occurred in patients with cardiac disease and usually with LV ejection fraction of less than 0.40; the prevalence of sudden death in Group I (11.5%) was higher than in Group II (4.8%) but the difference was not statistically significant. The prognosis of patients in Group II was the same as that of the general population. The results of this study suggest that PES enables identification of a subgroup of patients with complex ventricular ectopy in which ventricular tachyarrhythmias cannot be induced and the risk of sudden death is low; the management of patients with inducible ventricular tachyarrhythmias and normal LV function has to be determined case by case.

[Acute occlusion of the renal artery caused by an embolism of cardiac origin. Treatment by in situ thrombolysis]

An intra-arterial infusion of streptokinase successfully dissolved a large thrombus of the renal artery in a 54-year old male patient with old-standing mitral stenosis. This case illustrates the effectiveness of fibrinolysis in situ. This method provides complete arterial recanalization and preserves the renal function, thus enabling surgical embolectomy to be performed.

[Septal rupture repaired in the acute stage of myocardial infarction. Clinical, hemodynamic and angio-coronarography findings in the evaluation of surgical risk]

Between 1977 and 1987, 27 consecutive patients (16 men, 11 women, mean age 66 years, range 54 to 75 years) with ventricular septal rupture complicating acute myocardial infarction underwent surgical repair. The purpose of this retrospective study was to analyse the post-operative mortality factors from clinical, haemodynamic and operative data in all patients and also from coronary angiographic data in 23/27 patients whose haemodynamic status allowed this type of exploration. Seventeen patients (63 p. 100) died during the first post-operative month, 10 survived and were discharged. Factors that influenced the prognosis were: (1) inferiorly-located necrosis associated with a 75 p. 100 mortality rate (9 out of 12 patients), as opposed to 53 p. 100 (8 out of 15 patients) with anterior necrosis; (2) right ventricular dysfunction, observed in 83 p. 100 of patients with inferior necrosis and 53 p. 100 with anterior necrosis, which was responsible for 7 out of 9 deaths in the inferior necrosis subgroup and contributed to 3 out of 8 deaths in the anterior necrosis subgroup; this established a cause-effect relationship between right ventricular function and the overmortality of patients with inferior necrosis; (3) independently of the haemodynamic status, two- and three-vessel lesions (56 p. 100 of all lesions) which had an 84 p. 100 mortality rate as opposed to 40 p. 100 with one-vessel lesions; (4) the presence of a state of shock which was associated with a 78 p. 100 mortality rate as opposed to 55 p. 100 in patients without shock. We conclude that when permitted by the patient's haemodynamic status coronary angiography should be part of the pre-operative evaluation to assess the operative risk and guide the surgical procedure.

[Performance of endorectal echography in tumors of the rectum]

From November 1986 to December 1987, endorectal ultrasound (EUS) has been performed 57 times in a total of 54 patients. In the cancers of the low and mid rectum (n = 34), the extent of the tumoral infiltration was accurately assessed by preoperative EUS in 88% of cases. Sensitivity of tumor spread beyond the rectal wall was 0.96. Classification of lymph nodes was more hazardous. The muscular layer was intact in 5 villous adenomas. The diagnosis was difficult in the case of a huge and massively secreting tumour. In the follow-up of the patients after rectal resection(n = 11) or local excision (n = 3) for cancer, EUS allowed an accurate analysis of the suture line in 12 cases. Three submucosal recurrences were detected. The follow-up showed no recurrence in the other cases with a tumor-free suture line pattern. The literature confirms that EUS is a non invasive, efficient and inexpensive method in the preoperative staging of non stenotic rectal tumors. The problem of accuracy of lymph node staging has not been resolved. The technique shows some promise in detecting local recurrences.

Electrocardiographic characteristics of the escape rhythm in transient complete atrioventricular block induced by transcatheter electrical ablation of the atrioventricular junction

The electrocardiographic characteristics of spontaneous escape rhythm during complete heart block induced by transcatheter ablation of the atrioventricular junction was prospectively studied in 21 patients by periodically interrupting temporary pacing. The data derived from 13 of these 21 patients, in whom conduction recurred after the procedure, were analyzed. An escape rhythm was present in 12 patients 8.2 +/- 5.8 minutes after shock delivery at a cycle length of 1985 +/- 974 ms. The escape QRS had a configuration of right bundle branch block with left axis deviation in 9 patients, of right bundle branch block with normal axis in 1, of left bundle branch block with left axis deviation in 1, and 2 distinct morphologies in the remaining patient. After resumption of conduction, the conducted complexes were identical to the escape complexes in six patients, different only in axis in four patients, and different in morphology in two patients. This suggests that in the majority of patients the escape rhythm seen during transient heart block, induced by transcatheter ablation of the atrioventricular junction, presents a right bundle branch morphology with or without a left axis deviation, and most likely originates from an area above, or close to, the site of the anatomical damage.

[Wolff-Parkinson-White syndrome. Outcome of patients treated with anti-arrhythmia agents from data of electrophysiological examinations]

Seventy-two consecutive patients with electrocardiographic evidence of Wolff-Parkinson-White syndrome underwent electrophysiological study (EPS). Fifty-five of these patients (76 p. 100) had episodes of tachycardia, 11 experienced palpitations or syncopes and 6 were asymptomatic. The decision to prescribe an antiarrhythmic agent was reached on the basis of the patients' symptoms and EPS data. One patient was treated by surgery before the medical treatment was tried; 17 patients were discharged without treatment, 4 were discharged with an episodic and 50 with a preventive antiarrhythmic treatment. Among these 50 patients, 46 (92 p. 100) could be followed up for a mean period of 45.7 +/- 28 months. One died of lung cancer; 43 presented with spontaneous episodes of tachycardia, 4 were able to discontinue treatment at the end of the follow-up period since they had very few symptoms and 2 were lost sight of. Among the 37 patients under antiarrhythmic treatment followed up, 29 (78 p. 100) are well controlled, while 8 (22 p. 100) still present with episodes of tachycardia. A tachycardia-reducing pacemaker was implanted in 5 of these 8 patients. It therefore appears that 78 p. 100 of patients presenting with spontaneous episodes of tachycardia associated with WPW syndrome can be controlled with an antiarrhythmic treatment. This result was obtained after trying at least two types of antiarrhythmic agents in 86 p. 100 of the cases.(ABSTRACT TRUNCATED AT 250 WORDS)

[Cardiomuscular lysosomal glycogenosis in adults without known enzyme deficiency. A cause of familial myocardiopathy and lysosomal glycogen overload with normal acid maltase]

An unusual form of familial myocardiopathy is reported. The disease affected siblings entering adulthood and presented as subclinical skeletal muscle and patent cardiac muscle lesions. Quadriceps muscle biopsy performed in a young man who subsequently died of cardial failure revealed excessive lysosomal glycogen storage, as in type II glycogenosis, but biochemistry showed normal enzymatic activity. In a sister with hypertrophic myocardiopathy only leucocytes were examined; they also showed normal enzymatic activity. Other clinical manifestations of this form of familial myocardiopathy are hypoglycaemia and moderate skeletal muscle involvement. At histology, the image is that of Pompe's disease, but the acid maltase level is normal. The condition seems to be transmitted as an autosomal dominant trait.

[Complex ventricular extrasystole. Value of technics of programmed electric stimulation]

The incidence and significance of ventricular arrhythmia induced by programmed electrical stimulation in subjects with complex ventricular ectopy were studied in 46 consecutive subjects: 34 with heart disease, 12 with an apparently normal heart. The procedure consisted of delivering on one spontaneous and 2 imposed rhythms one, two, then three extrastimuli. Significant arrhythmia with more than 6 ventricular complexes was induced in 17 patients (37%), including 6 (13%) with sustained ventricular tachycardia and 11 with unsustained ventricular tachycardia. Induction of ventricular arrhythmia was observed in 12 of the 14 patients with a history of myocardial infarction. At the end of a mean follow-up period of 12 +/- 4 months, there were 2 sudden deaths, and 3 patients had clinically sustained ventricular tachycardia. Clinical ventricular tachycardia occurred in the group of 17 patients inducible during programmed electrical stimulation. The patients who died suddenly belonged to the group of 29 patients without induced ventricular arrhythmia. This study shows a high proportion of significant stimulation-induced arrhythmia in patients who had suffered from myocardial infarction more than 3 months previously and who had complex ventricular ectopy. Owing to the good condition of this group of patients after a mean follow-up of 12 months, we were unable to determine the influence of stimulation-induced arrhythmia on mortality. However, it must be noted that spontaneous sustained tachycardia occurred in the group of patients with significant induced ventricular arrhythmia.

Electrophysiologic properties of falipamil (AQA-39)--a new bradycardiac agent

Falipamil hydrochloride (AQA 39) is a new antiarrhythmic agent structurally related to verapamil. We evaluated the electrophysiologic properties of intravenous falipamil (1.5 mg kg-1 within 20 minutes) in 12 patients. The spontaneous cycle length was significantly (P less than 0.001) prolonged (+79 +/- 59 ms). Atrioventricular conduction was significantly (P less than 0.001) shorter due to AH interval shortening (-17 +/- 14 ms), most probably related to an anticholinergic effect. Similarly, the anterograde Wenckebach point occurred at a significantly (P less than 0.06) higher rate after falipamil (+10 +/- 7 beats min-1). No statistically significant effect was noted on the refractory periods of the AV node, although there was a trend to shortening. The refractoriness of the right atrium and ventricle was significantly prolonged. It is concluded that falipamil is a bradycardiac agent with electrophysiologic properties quite different from those of verapamil and similar to those of class IA antiarrhythmic agents.

[Evaluation of the prognosis of mitral valve prolapse]

It is not easy to evaluate the prognosis of mitral valve prolapse. First of all, a positive diagnosis is difficult: the clinical insufficiencies are ill-compensated by sonocardiography as it is less reliable than expected; the very existence of the "mitral valve prolapse" described by Barlow is being challenged. Secondly, the most severe complications of mitral prolapse are rare, with respect to its frequency. Some complications are currently well defined. Thus, severe mitral insufficiency, leading to valve replacement, affects elderly men more than young women, although the pathological lesions correspond to the same disease. Endocarditis is rare and only occurs when there is an audible murmur. Rhythm disorders are varied, with however, frequent junction tachycardias and a marked influence of catecholamines, which may explain the clinical effectiveness of beta-blockers. Unfortunately, severe complications are not as well known. Thus, the risk of sudden death and cerebral vascular accident cannot be figured out from large statistical studies. Only studies of some so called "risk" sub-groups, should allow a better knowledge of these two complications and a more effective prevention.

[Electro-mechanical dissociation concomitant with myocardial reperfusion in the acute phase of myocardial infarction]

An unusual case of transient electro-mechanical dissociation concomitant with myocardial reperfusion is reported. The patient had myocardial infarction caused by occlusion of the middle anterior interventricular artery relieved by injection of urokinase and plasminogen in situ. The dissociation could be documented by simultaneous ECG recording on 3 leads and direct intravascular recording of femoral arterial pressure, the patency of that artery, and its maintenance, being demonstrated by angiography. This clinical case can be added to the list of events which occur during reperfusion of the myocardium after prolonged ischaemia. Its mechanisms, so far, are purely conjectural.

Remote occurrence of high degree heart block following failure of transcatheter AV junctional ablation: incidence and clinical significance

We report on two patients out of a series of 22 who underwent transcatheter ablation of the atrioventricular (AV) junction. The procedure failed to induce permanent complete heart block in 15 patients, 12 of whom were in sinus rhythm with 1:1 AV conduction before hospital discharge. Of the 12 patients, two (16.6%) were found to be in high degree heart block, one month later. We discuss the mechanism of late occurrence of high degree heart block and we emphasize the need for systematic implantation of permanent ventricular or dual chamber pacemakers, despite failure of transcatheter ablation of the AV junction.

[Percutaneous aortic valvuloplasty by trans-septal approach]

Aortic valvuloplasty has recently been introduced in the treatment of some cases of aortic stenosis. In the case reported here, the aortic orifice was so difficult to traverse by the retrograde route that the obstacle was approached by trans-septal catheterization. The aortic area, initially estimated at 0.25 cm2, increased to 0.82 cm2 at the end of the examination. However, additional dilatation by the retrograde route was necessary, using a catheter 25 mm in diameter.

[Intravenous sotalol in the acute treatment of supraventricular tachycardias]

The effects of intravenous sotalol (0.5 mg/kg in 6 minutes) were studied in 23 patients with supraventricular tachycardia (ventricular rate greater than 120 bpm) after failure of placebo (isotonic dextrose). Thirteen patients had atrial flutter or fibrillation and 10 a junctional tachycardia of recent onset. Sinus rhythm was restored in 4 of the patients with atrial flutter or fibrillation and the ventricular rate was slowed significantly in 3 patients (less than 100 bpm). In 3 other patients the ventricular rate decreased (31 to 35 p. 100) but remained above 100 bpm. Sinus rhythm was restored in 3 of the 10 patients with a junctional tachycardia five to twelve minutes after beginning the injection. A slight slowing of the heart rate (13 to 27 p. 100) was observed in the other 7 patients but the frequency remained over 100 bpm. Overall, a satisfactory result was obtained in 10 patients (43 p. 100) including 7 cases in which sinus rhythm was restored. Sotalol was well tolerated in 21 patients; one patient complained of cold in the legs and one patient developed asymptomatic bradycardia (46 bpm). This study shows that intravenous sotalol may be useful in the emergency treatment of supraventricular tachycardia.

[Sinus dysfunction associated with catecholaminergic ventricular tachycardia. Therapeutic implications]

The presence of resting sinus bradycardia (less than or equal to 45 bpm) with junctional escapes in an 8 year old child with catecholamine induced ventricular tachycardia, raised the problem of an underlying sinus node dysfunction. This was an important consideration bearing in mind the potential risk of the high dose betablocker therapy aggravating the sinus bradycardia. Electrophysiological studies showed pathological sinus node recovery times. Betablocker therapy did not aggravate the bradycardia, even after 6 months' treatment. A review of the literature showed the association of sinus bradycardia and catecholamine-induced ventricular tachycardia to be relatively common (39 p. 100). However, no mention was found of aggravation of this sinus bradycardia by betablocker therapy.

[Delayed filling of the anterior interventricular artery. Apropos of 9 cases]

Selective coronary angiography has shown that typical angina pectoris may occur in the absence of atheromatous coronary stenosis. Other causes of these attacks of pain have been found: coronary spasm, small vessel disease, abnormal dissociation of haemoglobin or metabolic disturbances of the myocardial cell. Of all the patients undergoing coronary angiography in 1984 at the Centre Cantini, 9 had no classical coronary lesions but delayed filling of the left anterior descending artery. This syndrome was described for the first time in 1972 by Tambe as the "slow flow velocity syndrome". The aim of this study was to analyse the clinical, ECG and haemodynamic profiles of those patients. Five of them also underwent stress Thallium myocardial scintigraphy. An ergometrine provocation test was performed afterwards under ECG control. Delayed filling was appreciated by comparison with the other vessels and also by measuring the filling time which was two or three times longer than in a control series of 9 patients with angina and normal coronary arteries. The difference was statistically significant. These findings were only observed in strictly normal coronary vessels; they were reproducible and unaffected by the administration of nitrate derivatives. In our series all 9 patients were men with an average age of 51.4 years. One patient was asymptomatic and had a history suggestive of myocardial infarction, and 4 others had typical angina of effort: all had abnormal exercise stress tests. The other 3 patients had spontaneous atypical chest pain, normal resting ECG and a negative exercise stress test (impossible in one case). The five stress Thallium scintigraphies showed myocardial perfusion defects.(ABSTRACT TRUNCATED AT 250 WORDS)

A new method for evaluating the effect of antiarrhythmic drugs on atrioventricular nodal conduction

Electrophysiological variables were studied in 19 patients before and after one of three commonly used antiarrhythmic agents. The pacing rate at which alternating Wenckebach periods appeared in eight patients was significantly reduced by intravenous digoxin (0.01 mg/kg body weight). The atrioventricular nodal conduction time (A-H interval) and Wenckebach point were not significantly altered by digoxin. Intravenous propranolol (0.1 mg/kg body weight) in four patients did not affect the A-H interval, but it reduced the pacing rates at which the Wenckebach point and alternating Wenckebach periods occurred. Intravenous disopyramide (2 mg/kg body weight) significantly increased the pacing rate required to produce alternating Wenckebach periods but did not significantly alter the other indicators of atrioventricular conduction in seven patients. It is concluded that the pacing rate required to produce alternating Wenckebach periodicity may be a useful and sensitive variable in the evaluation of the effect of antiarrhythmic agents on atrioventricular nodal conduction.

[Treatment of recurrent ventricular tachycardias using oral propafenone]

The effect of oral propafenone on prevention of pacing-induced ventricular tachycardia (VT) was studied in 11 patients. All patients experienced documented sustained VT refractory to 4.1 +/- 2 antiarrhythmic agents per patient including amiodarone in 8. Programmed electrical stimulation was performed before and 48-72 hours after oral propafenone (900 mg/day) 2-3 hours after the last dose. Two patients developed spontaneous incessant VT before the scheduled date of the study on propafenone, and were classified as aggravation. Propafenone prevented pacing-induced VT in 2 patients (successful results). In 3 additional patients the results were partial, as non-sustained VT was induced on propafenone whereas sustained VT could be provoked during the control study. In the remaining 4 patients, oral propafenone failed to prevent pacing-induced VT. Tachycardia cycle length increased in 3 (C = 284 +/- 129 P = 450 +/- 202 ms) and was shorter in 1 aggravation. The 5 patients with successful or partial results (45.4 p. cent), underwent long-term therapy with a mean follow up of 5.6 +/- 4 months. Recurrence of VT occurred in 2. The remaining 3 are well controlled. This study demonstrates that propafenone is able to prevent pacing-induced VT in a limited number of patients. Stimulation techniques are useful in order to detect patients with potential pro-arrhythmic effect.

[Oral and intravenous bepridil in the treatment of recurrent sustained ventricular tachycardias. Electropharmacological study]

The antiarrhythmic properties of bepridil on ventricular tachycardia (VT) termination and prevention were studied in 16 patients using programmed electrical stimulation techniques. All patients were admitted for documented sustained VT resistant to 3.5 +/- 2.4 antiarrhythmic agents. Intravenous bepridil (2 mg/kg) successfully terminated 4 out of 8 and prevented 3 out of 8 patients with hemodynamically well tolerated sustained VT. Oral bepridil (800 mg day 500-600 mg the following days) prevented successfully pacing-induced VT in 7 patients (43.7 p. cent) and a partial result was obtained in additional 3 (18.7 p. cent). In 6 patients bepridil failed to prevent pacing-induced VT including 2 patients with a shorter cycle length on bepridil (classified as aggravation). Tachycardia cycle length lengthened in the remaining 4 a mean of 11 +/- 12 p. cent. One of the 7 patients with a good result presented on bepridil evidence of sinus node dysfunction. The remaining 6 underwent long-term therapy (600 mg/24 h). During a mean follow up of 19 +/- 4 months, 4 patients are well controlled, 1 presented a side-effect (paralytic ileus) and 1 a recurrence. This study emphasizes the antiarrhythmic properties of bepridil at the ventricular level and provides evidence of its usefulness in patients with recurrent sustained VT.

[Treatment of recurrent ventricular tachycardia with hydroquinidine. Evaluation of its efficacy with electrophysiological technics]

Electrophysiological investigations were used to test the efficacy of dihydroquinidine chlorhydrate (600 or 1 200 mg/day) in a prospective study of 18 patients with recurrent ventricular tachycardia documented by electrocardiography. These patients did not respond to an average of 3.1 +/- antiarrhythmic drugs, including amiodarone in 12 patients. Hydroquinidine was well tolerated in 17 patients but had to be withdrawn in 1 patient because of hypotension. The effect of hydroquinidine on ventricular tachycardia induced by programmed pacing was evaluated after a 48 to 72 hours treatment, 3 to 5 hours after the last dose. After hydroquinidine it was not possible to induce ventricular tachycardia in 10 patients (58.8%). In the other 7 patients, it was possible to induce a ventricular tachycardia under treatment. In one case, hydroquinidine aggravated the arrhythmia as the induced tachycardia had a shorter cycle. In the other patients, hydroquinidine lengthened the tachycardia cycle by an average of 94 +/- 79 ms. The right ventricular refractory period increased cycle by 44 +/- 23 ms. Long-term hydroquinidine was prescribed for 7 patients, twice in association with amiodarone. Relapse was observed in 2 patients, 1 and 5 months after the onset of treatment. Five patients were well controlled by the treatment. The results of this study demonstrate the efficacy of hydroquinidine for the prevention of tachycardia induced by stimulation and underline its value in the treatment of sustained, recurrent ventricular tachycardia. This study illustrates the illustrates the importance of electrophysiological techniques for the identification of patients likely to benefit from a given antiarrhythmic treatment.