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One-hundred-thirty patients underwent 53 electrophysiological studies including programmed atrial and ventricular stimulation and 96 atrial overdrive stimulations on an outpatient basis. The indications for electrophysiological study were disabling palpitation, syncope, or presyncope, intracardiac conduction disturbance, and bradyarrhythmia. In one patient the efficacy of oral antiarrhythmic drug therapy was evaluated by repeat electrophysiological study. Atrial overdrive stimulation was performed in patients with atrial flutter or atrial tachycardia. On the basis of the result of electrophysiological testing, 25 patients were believed not to require any treatment, 16 patients received new drug therapy, 7 patients underwent catheter ablation in a second session, 2 patients had either a pacemaker or an ICD implanted, and 1 patient continued to receive the drug therapy that had been tested. Atrial overdrive stimulation resulted in a regular sinus rhythm in 66 patients (69%). Except for one patient in whom atrial flutter could not be terminated, atrial fibrillation was induced in the remaining 30 patients. After the procedure, patients were monitored for 30 min in case of overdrive stimulation, and for approximately 3 h after electrophysiological study or 6 h if additional coronary angiography had been performed. Severe complications were not observed. In 10 cases minor hematoma occurred at the puncture site without serious sequelae.--Outpatient electrophysiological study as well as atrial overdrive stimulation are feasible and safe in a selected group of patients.

The purpose of this study was to test the efficacy, feasibility, and safety of outpatient radiofrequency catheter ablation in 162 consecutive patients. There were 83 men and 79 women at a mean age of 47 + 15 years; 13 patients underwent 2 and 1 patient 3 ablation procedures. In 167 cases patients suffered from highly symptomatic paroxysmal tachycardia associated with presyncope or syncope in 74. Severe palpitations were present in 7 cases and recurrent syncope in 1 case. One patient had an asymptomatic Wolff-Parkinson-White syndrome with a shortest RR-interval during atrial fibrillation of 150 ms. The mechanism of tachycardia was found to be atrioventricular nodal reentry in 78 cases, atrioventricular reentry involving an accessory atrioventricular pathway in 56, atrial fibrillation in 16, atrial flutter of the common type in 15, ectopic atrial tachycardia in 8, and idiopathic ventricular tachycardia in 3. Catheter ablation was performed in these 176 cases at an overall success rate of 86%. In 148 cases patients could be treated on an outpatient basis and were discharged after a maximal observation time of 3 hours in 28, and 24 hours in another 120 cases. Short-term follow-up was uneventful in these patients. After 28 ablation procedures patients had to be admitted to the hospital, because of pain at the puncture sites or after pacemaker implantation in 15 cases, because of minor complications in 12, and because of pericardial tamponade in 1 case. Another severe complication occurred in 1 patient after successful ablation of right atrial tachycardia. Three days after discharge the patient suffered from pulmonary embolism originating from a thrombus at the ablation site. After hospital admission the patient recovered completely. In general, complication rate was 2.27%. This study shows that catheter ablation can be performed effectively and safety on an outpatient basis.

To answer the question of whether pretreatment of complex coronary artery lesions via rotablation reduces the risk of subsequent PTCA, we compared the results of PTCA of 250 patients with Typ B- and C-lesions treated between April 1 and November 11 1991 (Group A) with a group of 437 patients treated between January 1 and May 1 1992 (Group B), for whom not only PTCA but also rotablation was available. Rotablation was successful in 102 of 119 procedures (85.7%), the rate of major complications was 1.8%. The primary success rate for treatment of all complex lesions was higher in group B (87.3%) in which 22.2% of the lesions were treated with the rotablator than in group A (83.1%). Dissection rate was similar in both groups (18.5% in group A, 17.5% in group B). In group B patients, however, dissections could be controlled more frequently by the use of a reperfusion catheter (21% vs 8.3% in group A). Serious complications caused by a dissection were not so often observed. In group B patients the rate of major complications due to dissection was lower (2.5% vs 4.4% in group A). In summary, pretreatment of complex coronary artery lesions via rotablation seems to increase the success rate of the following PTCA and to reduce its risks.

Significant bleeding at the puncture site is one of the most important problems in the care of patients undergoing interventional coronary procedures like PTCA, rotablation, laser angioplasty or stent implantation. This is due to systemic application of heparin, acetylic salicic acid and, in stent patients, even additional coumadine. Furthermore, the interventional systems implement catheter systems with a large inner and outer lumen leading to increased vessel trauma. To decrease the risk of bleeding and to reduce the time of pressure dressing and bed rest, a bovine collagen plug (VasoSeal) was used in 600 consecutive patients undergoing one of the above-mentioned interventional procedures. In the majority of patients (pts.) (474/600 = 79%) either no (404 pts.) or minimal (70 pts.) bleeding occurred. Bed rest could be reduced from more than 24 h to 6-12 h. In 65/600 pts. (11%) significant bleeding developed which could be controlled by compression. Bed rest in these patients was 13-20 h. Larger bleedings or complications occurred in 61/600 pts. (10.2%) and could be controlled conservatively in all but eight patients. One patient (0.2%) had a narrowing of the artery at the puncture site after the procedure, probably due to intraarterial plug application. In another patient (0.2%) embolization of the plug into the popliteal artery occurred which could be treated by embolectomy using a Fogarty-catheter. Arteriovenous fistulae or aneurysms developed in 8/600 pts. (1.3%) but these are no specific complications of the hemostatic device. The plug could not be placed in 13/600 pts. (2%), mainly in the beginning of the study.(ABSTRACT TRUNCATED AT 250 WORDS)

In patients with coarctation of the aorta, intravascular ultrasound can yield important additional diagnostic information concerning stenosis morphology and aortic wall structure that, thus far cannot be obtained with conventional angiography. For the first time, we were able to visualize, in vivo, the eccentric thickening of the posterior aortic wall, which is the typical morphological finding in patients with coarctation of the aorta, known from post mortem or intraoperative specimens. The additional information about stenosis morphology and aortic wall structure, obtained with intravascular ultrasound, is especially valuable for the newer interventional therapy of balloon angioplasty. With intravascular ultrasound, not only the direct quantitative assessment of the aortic cross-sectional luminal area, but also the immediate visualization of local dissections and aneurysms is possible. Using special angioplasty catheters with integrated ultrasonic crystals (which are currently under manufacturing development), a step-wise dilation with immediate evaluation of the therapeutical success may improve the short- and long-term results of balloon angioplasty. At present, intravascular ultrasound is still only an additional diagnostic tool. If it is combined with interventional balloon angioplasty, however, it could gain increasing clinical importance for the treatment of aortic coarctation in the near future.

This report describes the case of a 41-year-old patient with Wolff-Parkinson-White syndrome and recurrent, highly symptomatic episodes of atrial fibrillation (with rapid heart rates of a mean of 250 beats/min) in whom transvenous catheter ablation of the accessory pathway was successfully performed in a relatively short time during the arrhythmia. The feasibility of an abbreviated approach to the relatively time-consuming ablation procedure in Wolff-Parkinson-White syndrome is discussed.

An abdominal murmur was first heard in a now 46-year-old man four years after laminectomy at the age of 21. Signs of right heart failure and, ultimately, of global heart failure developed progressively and increasingly 20 years later. Echocardiography demonstrated enlargement of the right heart cavities, and atrial fibrillation was diagnosed. Cardiac catheterization revealed the typical picture of high output failure (cardiac output 13.9 l/min). Intra-arterial subtraction angiography demonstrated a fistula between the left iliac artery and vein. After operative closure of the fistula the signs of heart failure disappeared. Six months later a residual but insignificant fistula was still present, as well as persistent atrial fibrillation. Medical treatment having failed cardioversion successfully re-established sinus rhythm and the patient became symptom-free. Arteriovenous fistula after laminectomy is a rare cause of heart failure and often diagnosed very late. The prognosis is good once the fistula has been closed.

In 45 patients (15 female, 30 male; age 34 +/- 12 years) with Wolff-Parkinson-White syndrome: 1) the relation between electrophysiologic properties and location of accessory pathways and 2) the relationship between electrophysiologic properties of accessory pathways and adjacent atrial and ventricular myocardium was studied. Location of the accessory pathways was determined by catheter mapping of the coronary sinus and the tricuspid valve ring. There was no linear correlation between antegrade and retrograde effective refractory periods of accessory pathways and adjacent myocardial tissue. According to their location, accessory pathways were divided into right lateral (n = 4), anteroseptal (n = 6), posteroseptal (n = 10), left posterolateral (n = 8), and left lateral (n = 17). While analysis of variance revealed no differences between subgroups concerning retrograde effective refractory periods, antegrade effective refractory periods were significantly different (p less than .01). Moving in a clockwise direction around the mitral valve ring, antegrade effective refractory periods of the accessory pathways decrease from anteroseptal (321 +/- 30 ms) to posteroseptal (290 +/- 38 ms), left posterolateral (258 +/- 21 ms) and left lateral (246 +/- 27 ms), (Spearman R = 0.70m, p less than .01). Antegrade effective refractory periods of septally located accessory pathways (301 +/- 38) were significantly longer than of pathways located in the free wall of the ventricles (251 +/- 24, p less than .01).

10 patients with an accessory atrioventricular pathway were studied by means of programmed electrical stimulation to test the feasibility of tachycardia prevention with an extrastimulus delivered after the tachycardia-initiating beat. Reciprocating atrioventricular tachycardia was reproducibly initiated from high right atrium in all 10 patients with a single extrastimulus. A second extrastimulus delivered to the same site resulted in prevention of tachycardia in all patients, when this extrastimulus was given within a "preventive zone" which started 10 ms after the effective atrial refractory period of the tachycardia initiating beat. The average width of the preventive zone was 50 ms in our patients, independent of the initial tachycardia interval or tachycardia cycle length. Tachycardia prevention was always successful with a single atrial extrastimulus, whereas termination of an ongoing tachycardia required at least two atrial or ventricular extrastimuli.

Programmed electrical stimulation of the heart was performed in a 40-year-old man with documented recurrent, sustained ventricular tachycardia, which had proved refractory to standard medical therapy. In this patient, both the presence of several discontinuities in the atrioventricular (AV-)nodal conduction curves during atrial and ventricular stimulation and the varying time intervals of the AV-nodal echo phenomena suggested the presence of multiple AV-nodal pathways.

A case is reported in which the formation of a right atrial mass was detected by two-dimensional echocardiography 3 weeks after successful transvenous electrical ablation of the atrioventricular junction had been performed. The mass was attached to the atrial septum at the site where the electrode catheter used for the ablation had been located and it exhibited no mobility. It was interpreted as a right atrial thrombus induced by the ablation procedure. Although no pulmonary embolic events have been observed during a 7-month follow-up period, right atrial thrombus formation must be considered as a potentially dangerous complication of transvenous catheter ablation to control supraventricular arrhythmias.

A radio-frequency current was delivered via a catheter to the atrioventricular (AV) node in 13 patients with supraventricular arrhythmias (maximal heart rate 215/min). In nine patients with atrial fibrillation, three with AV nodal re-entry tachycardia and one with AV re-entry tachycardia, AV node conduction time was prolonged from 95 +/- 43 ms to 168 +/- 72 ms. In three patients the radio-frequency current had no lasting effect, necessitating AV node ablation with a direct-current shock. During a mean observation period of five months, all ten patients in whom the radio-frequency current had been successfully applied remained free of symptoms without any anti-arrhythmia treatment. There were no complications during or after treatment.

To assess the validity of train stimulation for the prevention of accessory pathway mediated atrioventricular tachycardia, thirteen patients were studied. Tachycardia was induced from high right atrium and coronary sinus by means of single extrastimuli; preventive stimulation at high right atrium and coronary sinus consisted of the delivery of a train of ten or eleven stimuli 10 ms apart, following the tachycardia initiating stimulus. Preventive train stimulation at the site of tachycardia induction was successful in all patients when the train exceeded the atrial effective refractory period of the initiating stimulus to achieve single atrial capture within the "preventive zone". In patients with a left-sided accessory pathway in whom tachycardia was induced from the coronary sinus, preventive stimulation at high right atrium failed because of interatrial conduction delay. It is concluded that train stimulation is an effective mode of prevention of atrioventricular reentrant tachycardia, yet preventive stimulation should be performed as close as possible to the reentry circuit to reduce interatrial conduction delay.

To assess the influence of time on the inducibility by programmed electrical stimulation of ventricular arrhythmias after acute myocardial infarction, we studied 18 patients on the 5th and 24th day after infarction with a stimulation protocol employing a maximum of 3 right ventricular extrastimuli during sinus rhythm and at 3 paced cycle lengths. All patients were without documented sustained ventricular arrhythmias (sustained ventricular tachycardia or ventricular fibrillation) prior to the investigation. Sustained ventricular arrhythmias were induced in 2 patients on day 5, but in 9 on day 24 after infarction. This difference in incidence was statistically significant (p less than 0.05), as was the change in the distribution ratio of induced sustained ventricular arrhythmias from day 5 to day 24 (p less than 0.05). The types of arrhythmia induced on day 24 were sustained ventricular tachycardia with a mean cycle length of 207 ms in 6 cases (5 monomorphic, 1 polymorphic), and ventricular fibrillation in 3 cases. These 9 patients did not differ from the remaining 9 patients in maximal CPK, infarct site, number of stenosed coronary arteries, global left ventricular ejection fraction, and in the results of 24-hour Holter monitoring, but they had a significantly shorter right ventricular effective refractory period (223 +/- 10 ms versus 259 +/- 28 ms; p less than 0.05). During the follow-up period of 24 +/- 5 months no patient died, had syncopal attacks, or developed spontaneous episodes of sustained ventricular arrhythmia. The timing of programmed electrical stimulation with a maximum of 3 right ventricular extrastimuli strongly influences the inducibility of sustained ventricular arrhythmias after acute myocardial infarction.(ABSTRACT TRUNCATED AT 250 WORDS)