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Objectives: This study evaluated accessory pathway location, its relation to retrograde P wave polarity on the surface electrocardiogram and radiofrequency ablation efficacy and safety in a large group of patients with permanent junctional reciprocating tachycardia., Background: Permanent junctional reciprocating tachycardia is an uncommon form of reciprocating tachycardia, almost incessant from infancy and usually refractory to drug therapy. It is characterized by RP > PR interval and usually by negative P waves in leads II, III, aVF and V4 to V6. Retrograde conduction occurs through an accessory pathway with slow and decremental properties. Although this accessory pathway has been classically located in the posteroseptal zone, other locations have been recently reported., Methods: The study included 32 patients (20 men, 12 women, mean [+/- SD] age 29 +/- 15 years) with a diagnosis of permanent junctional reciprocating tachycardia confirmed at electrophysiologic study. Seven patients had depressed left ventricular function. Radiofrequency energy was applied at the site of the earliest retrograde atrial activation during tachycardia., Results: There were 33 accessory pathways. The site of the earliest retrograde atrial activation was posteroseptal in 25 patients (76%), midseptal in 4 (12%), right posterior in 1 (3%), right lateral in 1 (3%), left posterior in 1 (3%) and left lateral in 1 (3%). Thirty pathways were ablated with a right approach; in 11 patients with posteroseptal pathway the ablation was performed through the coronary sinus. Three pathways were ablated with a left approach. Positive retrograde P wave in lead I suggested that ablation could be performed from the right side; if negative, it did not exclude ablation from this approach. All the accessory pathways were successfully ablated, with a median of 3 and a mean of 5.6 +/- 5 radiofrequency applications of 70 +/- 26 s in duration. In two patients with the accessory pathway in the midseptal zone, a transient second- and third-degree atrioventricular block, respectively, was observed after ablation. At a mean follow-up of 18 +/- 12 months, 31 patients (97%) are asymptomatic without antiarrhythmic therapy (95% confidence interval [CI] 84% to 99%). Recurrences were observed in four patients (13%) (95% CI 4% to 29%), three of whom had the accessory pathway ablated successfully at a second session. All patients with depressed left ventricular function showed a marked improvement after successful ablation., Conclusions: In our experience, most of the patients with permanent junctional reciprocating tachycardia had posteroseptal pathways; all these pathways were ablated from the right side. P wave configuration may be helpful in suggesting the approach to the site of ablation. Catheter ablation using radiofrequency energy is an effective therapy for permanent junctional reciprocating tachycardia.

Long-term prognosis, pharmacological prophylaxis and transcatheter ablation in a large group of patients with idiopathic verapamil-responsive left ventricular tachycardia (IVRLVT) are reported in this study. Thirty-three patients with a mean age of 27 +/- 16 years at their first IVRLVT episode, were studied retrospectively. Ventricular tachycardia was of the right bundle branch block morphology in all cases, with left axis deviation in 29 and right axis deviation in five (one patient had the two morphologies). Mitral valve prolapse was present in four patients; no heart disease was found in the remaining 29. Ventricular tachycardia could be electrophysiologically induced in 90% of the patients; Holter monitoring showed only sporadic ventricular extrasystoles in 76%; late potentials were found in 33% of the cases. At the end of a follow-up of 5.7 +/- 4.7 years, no patient had died. Thirty-one patients (94%) received a mean of 2.5 +/- 1.2 drugs; beta-blockers were effective in 71% of the cases, verapamil in 25%, class 1 drugs in 22%, class 3 drugs in 18%. Two patients who never received prophylaxis and four in whom it was stopped, were controlled with verapamil in case of recurrence. Six patients underwent catheter ablation; two with DC shock in whom it was successful in one, and four with radiofrequency energy, with a total success rate. The good prognosis of IVRLVT has been confirmed in a long-term follow-up; a new finding is the high efficacy of beta-blockers for prophylaxis. Radiofrequency transcatheter ablation is an effective and safe therapy for patients with symptoms not controlled by drug treatment.

The incidence of sudden death in the Wolff-Parkinson-White (WPW) syndrome is not well documented and probably underestimated. This retrospective study concerned 28 consecutive patients presenting with ventricular fibrillation either spontaneously (20) or during electrophysiological investigation (8) but whose characteristics allowed them to be assimilated into a single group. Their clinical and electrophysiological characteristics were compared with those of 60 consecutive patients with the WPW syndrome who had documented atrial fibrillation (and even reciprocating tachycardia) but never ventricular fibrillation. There were no significant differences between the two groups with respect to the following clinical parameters: sex, duration of symptoms, the type of tachycardia previously recorded, history of syncope and presence of underlying cardiac disease. With respect to the electrophysiological data, there were no differences in the point of anterograde block, the effective anterograde refractory period of the accessory pathway, the effective and functional refractory periods of the right atrium and atrial vulnerability. On the other hand, a significant difference was observed in the age of patients with ventricular fibrillation (29 +/- 13 years vs 36 +/- 12 years; p < 0.02), the prevalence of multiple accessory pathways (25% vs 7%; p < 0.04) with a dominant localisation in the postero-septal region (75% vs 47%, p < 0.026), preexcitation during exercise stress testing and under antiarrhythmic therapy (95% vs 68%, p < 0.037). The most discriminating parameter was the shorter RR interval during atrial fibrillation (172 +/- 23 ms vs 230 +/- 50 ms, p < 0.008). Multivariate analysis only showed one independent predictive factor: the minimum preexcited RR interval.(ABSTRACT TRUNCATED AT 250 WORDS)

We report the case of a woman treated with urokinase for acute pulmonary embolism with a right-sided heart thrombus. She developed life-threatening acute cor pulmonale which dramatically improved within 4 h with recombinant tissue plasminogen activator (rtPA). We emphasize the clinical interest of rtPA for the treatment of life-threatening pulmonary embolism.

The efficacy and safety of catheter ablation of accessory pathways (AP) was studied in 79 children (age, 4-16 years), using DC shocks (n = 25) or radiofrequency energy (n = 54). All patients had documented arrhythmias including ventricular fibrillation in four. Organic heart disease was present in four patients. AP locations were left lateral (n = 36), posteroseptal (n = 36), right lateral (n = 8), Mahaim fibres (n = 2) and right anteroseptal (n = 6). Seven patients had multiple AP. One patient had a preexcitation which appeared secondary to an atrio-infundibular connection (Fontan procedure). The ablation site of concealed or overt AP was identified by retrograde or anterograde conduction mapping, respectively. A mean of 2.6 +/- 1 cathodal shocks (80-160 J) was delivered to 25 patients over 29 sessions, resulting in initial AP ablation in all. Fulguration was uncomplicated in all except in one patient (4%) who developed a secondary complete AV block post-ablation. During a follow-up period of 30-69 months, intermittent preexcitation recurred in two asymptomatic patients, but no significant tachycardia was inducible at late electrophysiological study, including under isoproterenol infusion. Radiofrequency energy was applied to 54 patients during 62 sessions, using 20-40 watts for 30-60 s. AP ablation was initially achieved in all patients using a median of three impulses, without significant immediate side-effects. Two patients (4%) developed a short episode of blurred vision possibly due to a microembolism. After discharge, the follow-up period was 10 +/- 5 months (range 1 to 24). All patients but one (98%) were asymptomatic without any drug therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

We report two observations of significant left heart involvement in patients with the carcinoid syndrome assessed by transthoracic and transoesophageal echocardiography. Echocardiographic lesions of this kind have only been reported twice. In the present cases, there was mitral involvement with mitral regurgitation in one case and a mitro-aortic involvement with mitral and aortic regurgitation in the other. The mechanism of left heart lesions is unclear since in both cases no right-to-left cardiac shunt was present, as attested by colour Doppler and saline contrast transoesophageal echocardiography. The location of the primary tumour was unknown in one case and ileal in the other; no pulmonary metastasis was detected. The use of transoesophageal echocardiography might make it possible to detect left-sided cardiac lesions more frequently since they were found in anatomical series, in 30% of patients with carcinoid syndrome.

Junctional tachycardias may be related to intranodal reentry or to the existence of an accessory pathway. All are suitable for radical treatment by radiofrequency current applied either in the perinodal region or at the tricuspid or mitral atrioventricular rings respectively. 176 patients with intranodal reentry were treated by preferential modification of the rapid (8) or slow (167) anterograde pathway of the reentry circuit, with a 99% success rate (1 failure) and without significant complications, in particular atrioventricular block in the case of ablation of the slow pathway. 362 patients with one or more accessory pathways, patent or latent, were treated using the same type of energy. The ablation site was determined on the basis of indirect criteria and/or recording of the specific activity of the accessory pathway. The success rate here was 98%, once again without significant complications with the exception of those inherent to catheterisation procedures. Treatment duration time was 41 +/- 38 min in the treatment of intranodal reentry and 58 +/- 49 when one or more accessory pathways were responsible. X-ray exposure times were 14 +/- 14 min and 23 +/- 21 min respectively. Such results would justify the expectation of widened indications of the method.

Junctional tachycardias are among the most frequent or paroxysmal supraventricular tachycardias. They are due to a reentry mechanism and include the so-called nodal reentrant tachycardias as well as tachycardias which imply a patent or hidden accessory pathway. The prognosis of these tachycardias is usually benign, but it can be made unfavourable by repeated attacks or by the presence of an accessory pathway with short anterograde refractory period which exposes the patient to severe arrhythmia. Clinicians are now provided with a therapeutic armentarium that enables them to reduce easily any attack of junctional tachycardia, but also to prevent recurrences. The intracavitary ablation technique by application of radiofrequency currents ensures the radical cure of recurrent or threatening arrhythmias by suppressing the indispensable anatomical substrate of tachycardias.

Background: Various ablation methods have been proposed in the last few years in order to find a radical solution for atrioventricular nodal reentrant tachycardia. The first techniques were surgical, followed by modulation of the fast pathway, causing a prolongation of the P-R interval, the latter involving a 2 to 10% atrioventricular block risk. To reduce this risk, slow pathway ablation was then suggested, with the objective of abolishing atrioventricular reentry. The aim of our study was to evaluate how frequently the recording of peculiar slow potentials was possible in patients with atrioventricular nodal reentrant tachycardia, and to assess short-and long-term efficacy of an ablation technique involving the use of these potentials as electrophysiologic markers., Methods: One hundred and eighty-eight patients with typical atrioventricular nodal reentrant tachycardia were studied (mean age 47 +/- 18 years). Radiofrequency ablation was guided by peculiar slow potential recordings; when this was not possible, fast pathway ablation, or slow pathway ablation guided only by anatomic markers, were performed., Results: Potentials with peculiar electrophysiologic characteristics were found during sinus rhythm in the median posterior region of the septum, anteriorly to the coronary-sinus ostium, in 92% of patients. These characteristics included: low amplitude; the fact that they occupy the first part of the interval between the atrial and ventricular electrogram; their amplitude diminishes and disappears with increased frequency of atrial stimulation and/or with atrial extrastimulus. Typical atrioventricular nodal reentry tachycardia was no longer inducible in any patient at the end of the procedure with a median of 2 radiofrequencies application per patient. No II or III degree atrioventricular block was caused when ablation was guided by slow potential recordings. During an attempt at fast pathway ablation a complete atrioventricular block was caused in 1 patient. One hundred and eighty-four patients remained asymptomatic during a follow-up of 2 to 24 months; no one showed either a modification of atrioventricular conduction if compared to that found at hospital discharge or proarrhythmic effects. Four patients had one atrioventricular nodal reentrant tachycardia recurrence and a second successful ablation was performed in 2 of these 4 patients., Conclusions: Peculiar slow potentials, that can be used as electrophysiologic markers for slow pathway ablation, were recorded in the medio-posterior region of the septum in the majority of patients. The fact that this technique, using slow potential as an electrophysiologic marker, was successful in all patients, with very few recurrences and with no serious complications (no II or III degree atrioventricular block) makes it trustworthy and safe.

Atrioventricular nodal tachycardias due to intranodal reentry or to an accessory pathway are accessible to radical cure with radiofrequency currents applied either at the site of recording of characteristic slow potentials or at the tricuspid or mitral atrioventricular rings. One hundred and six patients with atrioventricular nodal reentry were treated by modification of the slow anterograde reentrant pathway with a 100% success rate and without any serious complications (especially atrioventricular block). One hundred and eighty six patients had one or more overt or latent accessory pathways and were treated by the same method. The ablation site was decided on indirect criteria and not by the recording of the specific activity of the accessory pathway. The success rate was 97%, also with no significant complications. The duration of the treatment was 41 +/- 22 min for the accessory pathways. The exposure time to ionising radiation was 14 +/- 14 min and 31 +/- 34 min respectively. These results suggest that the indications of radiofrequency current ablation could be extended.

Background: The purpose of this study was to describe a new technique for catheter ablation of left lateral accessory pathways (APs) by radiofrequency energy applied at the epicardium through the coronary sinus wall using a unipolar configuration., Methods and Results: In an overall group of 212 patients with left lateral APs, multiple endocardial ablation attempts of the AP were unsuccessful in eight patients. The mean +/- SD cumulative duration of previous attempts was 12 +/- 9 hours, using DC shocks and/or radiofrequency energy applied both at the atrial and/or ventricular AP insertions. Epicardial AP insertion was determined by bipolar and unipolar unfiltered distal electrograms by scanning the coronary sinus with a steerable 6F or 7F catheter with a 4-mm distal electrode. The local atrial to ventricular electrogram amplitude ratio was 0.3-1.6. At the ablation site, the catheter tip was slightly deflected toward the annulus to increase both the ventricular component of electrograms and contact with the epicardium. In four patients, epicardial electrogram timings were earlier than endocardial ones. The AP was ablated in seven of the eight patients with 20-30 W applied for 10-60 seconds. No complications occurred except a marked nonspecific pain during radiofrequency energy application; however, the catheter remained adherent to the coronary sinus wall, and its withdrawal was performed during a new radiofrequency application to decrease the risk of coronary sinus rupture. After ablation, echocardiograms, coronary artery angiograms, and levophase coronary sinus angiograms showed no abnormality in all patients except two who had a probable mural thrombus in the coronary sinus. AP conduction remained abolished for 1-10 months of follow-up in seven patients., Conclusions: Radiofrequency catheter ablation of left lateral APs can be achieved effectively and relatively safely via the mid or distal coronary sinus when endocardial approaches are unsuccessful.

Unlabelled: We assessed anterograde conduction electrogram parameters at successful ablation sites according to accessory pathway (AP) location and compared them to the most favorable electrograms at unsuccessful sites. A median of three radiofrequency energy impulses was applied to ablate 97% of 136 APs versus four impulses to ablate 90% of 65 concealed APs. Electrograms at successful sites showed variable A/V ratio (0.04-7), and a QS pattern of unipolar ventricular wave in 90%. Electrograms were different in right versus left AP: AV time 29 +/- 7 versus 38 +/- 10; and timing of ventricular deflection: 17 +/- 9 versus 2 +/- 9 msec, respectively. Analysis in each patient of the mapping parameters at successful versus "most favorable" unsuccessful sites showed an improvement in at least one parameter in 55%, no apparent change in all parameter values in 30%, and even less favorable parameters in 15% of patients. In patients with manifest AP, overall comparison of electrograms at successful versus unsuccessful sites showed no difference in A/V ratio (1.3 +/- 1.5 vs 1.2 +/- 1.6), unipolar pattern distribution, and AV time (34 +/- 10 vs 35 +/- 9), but earlier bipolar main ventricular potential (-4 +/- 12 vs -1.5 +/- 10 msec) and unipolar intrinsic deflection timings (-5.2 +/- 11 vs -1.8 +/- 10 msec). In patients with concealed AP, a retrograde continuous electrical activity was recorded in 72% of successful versus 38% of unsuccessful sites (P = 0.03)., Conclusions: Electrogram characteristics at successful radiofrequency ablation are different in right and left manifest AP.(ABSTRACT TRUNCATED AT 250 WORDS)

Arrhythmogenic dysplasia of the right ventricle is a common cause of ventricular arrhythmia. It is important to reach a diagnosis, due to the risk of sudden death, particularly as this may be the first sign of the disease. Diagnosis is based on the angiographic demonstration of a morphological or structural abnormality of the right ventricle, and non-invasive tests are relatively insensitive. From a case investigated in 1984, the authors carried out a prospective determination of the diagnostic value of the isoprenaline test in 61 patients suffering from arrhythmogenic dysplasia of the right dysplasia confirmed by angiography. High concentrations (8-30 micrograms/min) of isoprenaline were continuously infused over a period of 3 minutes, regardless of the heart rate achieved. In a control group of 50 subjects with no myocardial disorder, isoprenaline induced monomorphic wave-burst arrhythmia in only one patient (2%). In the subjects affected by right ventricular arrhythmogenic dysplasia, isoprenaline induced one or more episodes of wave-burst ventricular arrhythmia in 52 patients (85%): one triplet in four patients, several episodes of wave-burst arrhythmia in 31 patients and prolonged ventricular tachycardia in 17 patients. Polymorphic arrhythmia occurred in 80% of cases, but left lag forms predominated. High-amplification ECG demonstrated late potentials in 66% of cases, i.e. in 80 and 62% of patients with and without prolonged VT respectively. The isoprenaline test or high-amplification ECG gave abnormal results in 58 of the 61 patients, with a cumulative sensitivity of 95 percent.

Several epidemiological studies have shown decreased cardiovascular mortality and a lower incidence of coronary artery disease in subjects with high dietary intakes of Omega-3 polyunsaturated fatty acids. It has since been shown that Omega-3 fatty acids have a number of beneficial effects in the prevention of atherosclerosis in man: reduction of blood pressure, modifications of lipoprotein metabolism, modifications of haemostasis (increased bleeding time and reduced platelet aggregation), decreased plasma fibrinogen, modifications of the metabolism of arachidonic acid and its derivatives (decreased thromboxane and leukotriene synthesis, increased prostacyclin synthesis). Therefore, Omega-3 polyunsaturated fatty acids have several beneficial effects on the presumed mechanisms of atherogenesis and/or its complications: they could represent an original and seductive solution to the problem of prevention of cardiovascular disease.

Background: Ablation of the slow pathway has been performed to eliminate atrioventricular (AV) nodal reentrant tachycardia (AVNRT) either by a surgical approach or by using radiofrequency catheter technique guided by retrograde slow pathway activation mapping. From previous experience of midseptal and posteroseptal mapping, we were aware of the existence of peculiar slow potentials in most humans. Postulating their role in AVNRT, we studied these potentials and the effects of radiofrequency energy., Methods and Results: Sixty-four patients (mean age, 48 +/- 19 years) with the usual form of AVNRT were studied. Slow, low-amplitude potentials were recorded when using the anterograde AV conducting system. Slow potentials occupied all (giving a continuum of electrograms) or some of the time between the atrial and ventricular electrograms. Their most specific patterns were their progressive response to increasing atrial rates, which resulted in a dramatic decline in amplitude and slope, a corresponding increase in duration, and a separation from preceding atrial potentials until the disappearance of any consistent activity. Slow potentials were recorded along a vertical band at the mid or posterior part of the septum near the tricuspid annulus. Radiofrequency energy applied at the slow potential site resulted in interruption of induced tachycardia within a few seconds and rendered tachycardia noninducible in all patients. A median of two impulses was delivered to each patient. In 69% of patients, postablation atrial stimulation cannot achieve a long atrial-His interval, which previously was critical for tachycardia induction or maintenance. No patient had AVNRT over a follow-up period of 1-16 months, and all had preserved AV conduction. In all except two patients, the PR interval was unchanged. In 47 patients, long-term electrophysiological studies confirmed the efficacy of ablation and the nonreversibility of results by isoproterenol; however, echo beats remained inducible in 40% of patients., Conclusions: An area showing slow potentials is present at the perinodal region in humans. In patients with AVNRT, application of radiofrequency energy renders tachycardia noninducible through the preferential modification of the anterograde slow pathway. With present clinical methods, the exact origin and significance of these physiological potentials cannot be specified.

The effect of successful catheter ablation of overt accessory pathways on the incidence of atrial fibrillation (AF) was studied in 129 symptomatic patients with (n = 75) or without (n = 54) previous documented AF. Fourteen had had ventricular fibrillation. Factors predictive of recurrence were examined, including electrophysiologic parameters. Atrial vulnerability was defined as induction of sustained AF (greater than 1 minute) using single, then double, atrial extrastimuli at 2 basic pacing cycle lengths. When compared to patients with only reciprocating tachycardia, patients with clinical AF included more men (77 vs 54%, p = 0.008) and were older (35 +/- 12 vs 29 +/- 12 years, p = 0.01). They had a significantly shorter cycle length leading to anterograde accessory pathway block (252 +/- 42 vs 298 +/- 83 ms, p less than 0.001), greater incidences of atrial vulnerability (89 vs 24%, p less than 0.001) and subsequent need for cardioversion (51 vs 15%, p less than 0.001). After discharge, the follow-up period was 35 +/- 12 months (range 18 to 76); 7 patients with previous spontaneous AF (9%) had recurrence at a mean of 10 months after ablation. Age, presence of structural heart disease accessory pathway location, atrial refractory periods and accessory pathway anterograde conduction parameters were not predictive of AF recurrence. Persistence of atrial vulnerability after ablation was the only factor associated with further recurrence of AF. Atrial vulnerability was observed after ablation in only 56% of patients with previous AF versus 89% before ablation. It is concluded that successful catheter ablation of accessory pathways prevents further recurrence of AF in 91% of patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Primary cardiac leiomyosarcoma is a very rare condition. Only 15 cases have been reported in the literature. We report the case of a 27 year old man admitted to hospital for chest pain in March 1985. Echocardiography showed a right ventricular tumour which was completely resected at surgery. The diagnosis of leiomyosarcoma was confirmed by histological examination. After 22 months follow-up, the patient was still alive despite pulmonary metastases. The diagnosis of cardiac tumour used to be made post-mortem but since the introduction of new methods of investigation, especially 2D echocardiography, the diagnosis can be made at an early stage and allows rapid surgical resection, the only means of obtaining the histological diagnosis and of completely curing benign tumours.

Fifty-four patients with a posteroseptal accessory connection and symptomatic tachycardias underwent catheter ablation of the anomalous pathway. Eight had the permanent form of reciprocating tachycardias (long RP' tachycardia) and 46 had a left posteroseptal preexcitation marked by a prominent R wave in lead VI. In 14 of 19 patients, ventriculoatrial conduction time during tachycardia lengthened in conjunction with functional left bundle branch block; this behaviour was significantly different from a series of patients with right posteroseptal preexcitation in which functional left bundle branch block lengthened the ventriculoatrial time in only one of 12 patients. A quadripolar electrode catheter was left within the proximal coronary sinus in order to locate the earliest atrial or ventricular activation site. The appropriate bipole was used as the radiographic and electrophysiological reference of the insertion of the accessory pathway. A catheter was then positioned on the septal side of the right atrium, outside the coronary sinus, so that atrial activity during reciprocating tachycardia and ventricular activity during preexcitation were synchronous with or earlier than that recorded within the proximal coronary sinus. Accessory pathway potential was not recorded in any patient. Early ventricular potential occurring --1.5 +/- 8 ms relative to delta wave onset was present at that site. In 38 patients, including 5 with permanent junctional tachycardia, high current (14 mA) pacing yielded direct ventricular paced QRS complexes (no delay spike-QRS) with a morphology similar to left posteroseptal maximal preexcitation. Slight movements of catheter position yielded significantly different pace-maps. One to eight 160 J cathodal shocks (510 +/- 213 J cumulative per patient) were delivered at this site in 61 sessions. Following fulguration, tachycardia recurred without drugs in only one patient over a follow-up period of 20 +/- 13 months. Asymptomatic intermittent preexcitation recurred in two patients. In all patients with long RP' tachycardia, the ablation procedure was successful without the need for drugs or permanent cardiac pacing. A long-term follow-up electrophysiological study in 18 patients demonstrated that conduction through the anomalous pathway was absent in 16 and deeply altered in the two patients with intermittent preexcitation; no tachycardia was inducible in any patient. In conclusion, catheter ablation of left posteroseptal accessory pathways is a feasible procedure using a right atrial approach outside the coronary sinus. This technique is also effective for the treatment of the permanent form of reciprocating tachycardia.

Background: Transcatheter electrical ablation has been used in the treatment of arrhythmias, and most experience has been obtained by ablating the normal atrioventricular conduction system. Less information is available on ablation of atrioventricular accessory pathways., Methods and Results: Catheter ablation of overt accessory pathways was attempted in 135 patients with 142 distinct pathways, including 21 right parietal or anteroseptal, 47 posteroseptal, and 74 left lateral pathways. We sought to identify the type and value of electrophysiological parameters associated with successful ablation outcome. For this purpose, the unipolar recording mode was used in addition to bipolar anterograde and retrograde parameters. With a mean follow-up of 16 +/- 6 (mean +/- SD) months, fulguration was successful in eliminating preexcitation in 129 patients (96%), including all seven with two distinct accessory pathways. The first ablation attempt was successful in 110 patients, and two or more attempts were performed in 25 patients. Bipolar electrograms associated with success of fulguration showed a shorter atrioventricular conduction time (40 +/- 13 versus 53 +/- 17 msec, p less than 0.0001) and an earlier main ventricular deflection relative to delta wave onset (-1.7 +/- 10 versus 5 +/- 7 msec, p less than 0.001) than electrograms associated with unsuccessful outcome. The only parameter dealing with retrograde conduction (i.e., ventriculoatrial conduction time during reciprocating tachycardia) was not predictive (86 +/- 17 versus 93 +/- 17 msec). Neither was the atrial to ventricular electrogram amplitude ratio. Two unipolar parameters were found to be predictive of successful outcome: 1) The three different patterns PQS, P-QS, P-rS of unipolar waves recorded at the annulus were associated with respective success rates of 97%, 78%, and 55% (p less than 0.001). 2) Intrinsic deflection timing occurred -4 +/- 8 and 6 +/- 7 msec relative to delta wave onset in successful attempts and in failures, respectively (p less than 0.001). Logistic regression analysis revealed a single independent factor predictive of success, the unipolar pattern (p = 0.03), with an odds ratio of 7:1 (PQS pattern versus P-rS pattern). In the group of 18 patients who underwent a first unsuccessful but second successful attempt, comparison of electrograms revealed no difference in the ventriculoatrial conduction time but a significant improvement in anterograde parameters and unipolar pattern distribution., Conclusions: Some distinctive electrogram patterns concerning anterograde conduction are associated with success of accessory pathway fulguration. The unfiltered unipolar recording mode (PQS pattern) contributes significantly to optimizing the accuracy of accessory pathway localization.

The frequency of cardiac lesions in AIDS patients is diversely evaluated. At post-mortem examination macroscopic lesions are said to have been found in 20 percent of the patients, and microscopic lesions in 50 percent. In some clinical studies, up to 55 percent of the patients had echocardiographic abnormalities. All three cardiac wall layers may be involved. Cases of myopericardial Kaposi's sarcoma or non-Hodgkin's lymphoma have been described, together with infectious myocarditis or pericarditis, non-obstructive cardiomyopathy, aseptic fibrinous pericarditis, marantic endocarditis and other, less frequent lesions.

The dynamic behaviour of the QT interval was studied in 13 patients with a prolongation of greater than 80 ms of the QT interval of the QRS complex following a post-extrasystolic pause. Normal repolarisation under basal conditions (QTc 410 +/- 30 ms) was significantly (p less than 0.001) prolonged after pauses (QTc 512 +/- 90 ms). The study protocol included the measurement of QT during a Holter recording, an exercise test, Valsalva's manoeuvre and the isoprenalin test. Hydroquidine 600-900 mg/d was given to evaluate its action on ventricular repolarisation. The longest sinus cycles seen on the night Holter tracing (mean: 1,395 +/- 666 ms) were accompanied by normal repolarisation (QTc 380 +/- 30 ms). In contrast, exercise or Valsalva's manoeuvre caused a prolongation of QTc (QTc greater than 460 ms) in 11 patients out of 13: exercise QTc 471 +/- 54 ms; Valsalva QTc 480 +/- 50 ms. No arrhythmia occurred during these dynamic manoeuvres nor during the isoprenalin test. Hydroquinidine (mean: 729 mg) induced a QTc of greater than 500 ms in 6 patients out of 13 (46%). A triplet suggestive of a "torsade de pointes" was seen in one patient only. In conclusion, patients with a post-extrasystolic T wave abnormality under basal conditions were shown to fail to appropriately adapt their QT interval during autonomic stimulation manoeuvres and the prescription of hydroquinidine at the usual dose induced a mean QTc of greater than 500 ms in 46% of them.

This report describes a catheter ablation technique to treat atrioventricular nodal reentrant tachycardia while preserving anterograde conduction, and its application in 42 patients with drug-refractory repetitive episodes of tachycardia. One of these patients had common and reverse forms of tachycardia. Using atrial activation in the His-bundle lead as a reference, the optimal ablation site was selected by positioning an electrode catheter to obtain a synchronous or earlier atrial activation than the reference during tachycardia. At this site, His-bundle deflection was completely absent, or was present at a low amplitude (less than 0.1 mV). In the majority of patients, these criteria were found in the immediate vicinity of the site of proximal His-bundle recording (adjacent to the reference catheter). Shocks of 160 or 240 joules (J) were delivered at this site (mean +/- SD = 518 +/- 392 J/session) with a resulting preferential abolition of impairment of fast retrograde conduction. Anterograde conduction, though modified, was preserved in all patients, except for four (10%) patients who remained in complete heart block. Thirty patients (70%) remained free of arrhythmia without medication or pacemaker for a mean follow-up period of 23 +/- 13 (2-63) months. Six other patients (15%) were controlled with a previously ineffective medication.

Arrhythmogenic right ventricular disease is a potential cause of ventricular arrhythmias. Diagnosis is important due to the risk of sudden death, particularly as first symptom. Diagnosis is based on the angiographic demonstration of abnormal right ventricular morphology and function, while the sensitivity of noninvasive tests is relatively low. Following a particular observation studied in 1984, we prospectively assessed the diagnostic value of high dose isoproterenol infusion in 44 patients with an angiographically determined arrhythmogenic right ventricle. A continuous infusion of isoproterenol (8-30 micrograms/min) was administered during a 3-minute period, regardless of the obtained heart rate. In a control group of 50 patients without structural heart disease, isoproterenol induced a monomorphic ventricular tachycardia salvo in only one patient (2%). In patients with an arrhythmogenic right ventricle, isoproterenol induced one or more ventricular tachycardia runs in 39/44 cases (88%): one triplet in three patients, several runs in 23 patients and a sustained ventricular tachycardia in 13 patients. Arrhythmia was polymorphous in 85% of cases, but left bundle branch block morphology was the predominant pattern. In conclusion, high dose isoproterenol is a highly sensitive test for the diagnosis of arrhythmogenic right ventricular disease.

Two hundred and forty-eight patients with refractory arrhythmias related to an accessory pathway underwent catheter ablation. Cathodal shocks (160 to 240 joules) were delivered through the distal electrode of a standard catheter (usually a quadripolar electrode catheter with 5-mm interelectrode distances). A paddle electrode positioned opposite to the catheter served as the anode. Ablation of 24 right anteroseptal, 16 right parietal, 86 posteroseptal, 120 left parietal and four Mahaim pathways was clinically successful in eliminating symptomatic tachycardia in 236 patients (greater than 96%) over a follow-up of 3 to 64 months. There was no procedure-related death but two patients developed a ventricular fibrillation at the fifth and seventh day, respectively. The latter led to a sudden death since this side effect occurred after discharge. There were no instances of systemic embolus but one pericardial effusion required subxiphoid needle drainage 6 weeks after the procedure. Other complications included: AV block in four patients with posteroseptal and in one with a right anterior septal pathway. In conclusion, a successful clinical outcome may be achieved in most patients. Catheter ablation is an important alternative to cardiac surgery and in our opinion represents first-line treatment when therapy is required.

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.

Three patients with refractory preexcited tachycardia implicating Mahaim fibers underwent attempted catheter ablation of the accessory pathway. In the absence of demonstrable retrograde conduction in Mahaim fibers, we located the accessory pathway ventricular insertion site using the criteria of concordance between paced and spontaneous QRS morphologies during pace-mapping and earliest onset of local electrogram relative to surface preexcited QRS. At this site, a QS-like pattern of unfiltered unipolar electrograms with steep downstroke was recorded. The optimal site appeared radiologically at the right ventricular anterior wall or the adjacent septum, 2-4 cm from the tricuspid anulus. Three to six 160-J shocks were delivered at this site using an anterior chest wall plate as anode. After fulguration, conduction through the Mahaim tract was absent. A right bundle branch block persisted in two patients. All patients remained free of preexcited tachycardia during 12-16 months of follow-up. Postablation electrophysiological assessment showed no preexcitation in any patient. No reciprocating tachycardia was inducible, even during isoproterenol infusion. Atrioventricular nodal conduction parameters were unchanged from baseline study. Catheter ablation of Mahaim fibers is an effective alternative method for the treatment of tachycardias that include the accessory pathway in the circuit.

We applied a new technique of catheter ablation to treat atrioventricular nodal reentrant tachycardia and preserve anterograde conduction, performing this procedure in 21 patients with repetitive episodes of tachycardia refractory to antiarrhythmic drugs. Using atrial activation in the His-bundle lead as a reference, we selected the optimal site of ablation by positioning an electrode catheter so that atrial activation occurred simultaneously with or earlier than the reference activation during tachycardia. At this site, the His-bundle deflection was completely absent or was present only at a low amplitude (less than 0.1 mV). In the majority of patients, these criteria could be met by withdrawing the catheter 5 to 10 mm from the site of the His-bundle recording (adjacent to the reference catheter). Shocks of 160 or 240 J were delivered at this site (cumulative energy [mean +/- SD], 689 +/- 442 J). Treatment resulted in preferential abolition or impairment of retrograde nodal conduction. Anterograde conduction, although modified, was preserved in 19 patients; complete heart block persisted in 2 patients. Sixteen patients remained free of arrhythmia, without medication or implantation of a pacemaker, for a mean follow-up period of 14 +/- 8 months (range, 7 to 42). Tachycardia was not inducible in 14 patients in a follow-up electrophysiologic study performed 3.6 +/- 6 months after the procedure. We conclude that catheter ablation is an effective alternative for the treatment of atrioventricular nodal tachycardia in patients with drug-resistant tachycardia.

Following acute intoxication with alcohol, 8 patients developed 16 episodes of arrhythmia, including 15 supraventricular tachycardias and one torsade de pointe. Seven of the 8 patients were chronically abusing of alcoholic drinks. None of the patients had clinically obvious cardiac pathology nor echocardiographic evidence of myocardiopathy. In 7 of them, however, baseline electrocardiograms disclosed disorders of intra-atrial conduction. The role of the different factors which might determine the occurrence of arrhythmia (notably alcohol, the autonomic nervous system, associated metabolic abnormalities and absorption of medicines) is discussed.

Severe fasting hypoglycaemia were observed in three patients treated with cibenzoline, a new class I antiarrhythmic drug. Retrospective analysis of electrocardiographic changes and serum level determinations showed that these reactions were contemporaneous with intoxication by overdosage of the drug. None of the patients was taking any other drug known to produce this adverse reaction, and in the absence of any other cause of hypoglycaemia, we concluded that it was related to the administration of cibenzoline. Thus, cibenzoline is yet another class I antiarrhythmic agent producing hypoglycaemia as an adverse reaction. Serum insulin levels measured in two of the three patients during hypoglycaemia were inappropriately high, suggesting that cibenzoline might stimulate insulin secretion.