Anterior cruciate ligament reconstruction alters the patellar alignment.

Although there are many articles dealing with anterior cruciate ligament (ACL) reconstruction, there are none dealing with the possibility of changes of the patellofemoral alignment after these procedures. Forty-six patients were evaluated preoperatively and 1 year postoperatively, after undergoing intra-articular ACL reconstruction, for changes of the patellofemoral alignment. Patella-tilt and congruence angles were measured on tangential view radiographs that were taken in the supine position. Analysis of covariance was performed and revealed a significant change of the congruence angle 1 year postoperatively. The patella-tilt did not change. One year postoperatively, the patella shifted on average 5 degrees medially after ACL grafting. It can be deduced that anterior knee pain after ACL reconstruction could be caused by distinct changes in the patellofemoral alignment.

Shortening of the patellar tendon after anterior cruciate ligament reconstruction.

In this prospective study, patellar height changes were investigated after anterior cruciate ligament (ACL) reconstruction with a mean follow-up of 22.4 months. A total of 114 patients were included. Fifty-two patients (group A) were treated by multiple suture repair, 27 patients (group B) underwent acute ACL reconstruction, and 35 patients (group C) underwent ACL reconstruction > or =6 weeks after injury with a patellar tendon graft. The patellar vertical height ratios (VHR) were evaluated preoperatively (VHR 1), 6 months postoperatively (VHR 2), and at follow-up (VHR 3). For the studied questions, the following answers were obtained: (1) The change of the patella height was the same in all three groups (i.e., disregarding the different surgical procedures). (2) The time elapsed between injury and ACL reconstruction did not influence the shortening of the patellar tendon. (3) Women showed a more pronounced shortening of the patellar tendon than did men. (4) A significant shortening of the patellar tendon occurred in 30% of our patients, and the process of shortening was finished 6 months postoperatively. (5) Anterior knee pain was present in 27.2% of our patients and occurred significantly more often after patellar tendon graftings. (6) Age had no influence on the changes of the patellar height.

Twisting of patellar tendon grafts does not reduce their mechanical properties.

The purpose of this study was to investigate whether the twisting of a patellar tendon (PT) graft improves or reduces its mechanical properties. Twenty-seven pairs of 10 mm cadaveric PT grafts were tested at a strain rate of 10% min(-1). For each pair, the left specimen served as an unmanipulated control while the right specimen was either left untwisted, twisted + 90 degrees, or twisted - 90 degrees. All avulsion failures were excluded from the data analysis, focusing only on pure in-substance tendon ruptures. Higher ultimate load values than previously reported were obtained for both the twisted and untwisted specimens, without a statistical significant difference between the two. The values obtained for the left and right specimens from Group A were 4014+/-319 and 3973+/-245 N, from Group B 3613+/-207 and 3891+/-14 N, and from Group C 3997+/-278 and 4415+/-507 N, respectively. Stiffness and failure strain were not influenced by the twisting. Neither the presence of a twist, nor the direction of the twist were found to increase the ultimate load of the 10 mm cadaveric patellar tendon graft. Therefore, recommendation for twisting cannot be assessed to its mechanical properties.

Laser catheter coagulation of atrial myocardium for ablation of atrioventricular nodal reentrant tachycardia. First clinical experience.

A new technique for ablation of atrioventricular nodal reentrant tachycardia, using catheter-directed continuous wave Nd-YAG laser light, 1064 nm, via a novel pin-electrode laser catheter, was applied in 10 patients aged 15-63 years (mean 43 years). A total of 22 laser pulses, 1-5 per patient, at 20 or 30 W, of 10-45 s (mean 27 s) were aimed at the postero-inferior aspect of the tricuspid annulus. In all patients the tachycardia was rendered non-inducible at baseline as well as during orciprenaline administration. The amplitudes of the local atrial potentials diminished from 2.0 +/- 0.5 before to 0.4 +/- 0.4 mV after ablation, atrio-His intervals increased from 73 +/- 7 to 157 +/- 36 ms. Anterograde atrioventricular nodal refractory periods (212 +/- 31 vs 238 +/- 31 ms) and Wenckebach rate (174 +/- 8 vs 167 +/- 8 beats.min-1) did not change significantly (P > 0.05). There were no complications or recurrent arrhythmias in a follow-up of 12-35 (mean 27) months. Anatomically guided laser catheter coagulation of the postero-inferior aspect of the tricuspid valve ring is a safe and effective method for the cure of patients with common atrioventricular reentrant tachycardia.

[Catheter ablation of accessory atrioventricular conduction pathways in all locations--consecutive results of a new curative therapy of paroxysmal supraventricular tachycardia]. / Katheterablation von akzessorischen atrioventrikulären Leitungsbahnen in allen Lokalisationen--konsekutive Ergebnisse einer neuen kurativen Therapie der paroxysmalen supraventrikulären Tachykardien.

Accessory atrioventricular pathways are a frequent cause of paroxysmal supraventricular tachycardias. This study analyses our results with a recently developed therapeutic approach-radiofrequency (RF) catheter ablation. This was applied in 150 consecutive patients (97 men, 53 women, mean age 42 +/- 15 years) with a total of 159 accessory pathways in all locations. All but 4 patients were symptomatic, with a spectrum ranging from palpitations (146 patients), syncope (39 patients) to aborted sudden death (2 patients). Prior to ablation, 115 patients had received long-term treatment with up to 4 antiarrhythmic drugs unsuccessfully. The mean number of applied current pulses was 12 +/- 14, and the mean cumulative procedure duration was 256 +/- 243 minutes, with a cumulative fluoroscopy time of 49 +/- 72 minutes. Patients with left-sided pathways were approached via the retrograde aortic approach in 88/90 cases. One-hundred fifteen patients were treated in a single session, repeat sessions were required in the remaining 35 patients. The predominant sites of interruption of right-sided and left-sided accessory pathways were their atrial and ventricular insertion, respectively. Long-term cure was achieved in 141 patients (94%), non-life-threatening complications were observed in 3 patients (2%). These results compare well with published studies on large patient collectives and demonstrate that RF catheter ablation, which is highly cost effective, is the therapy of choice to cure symptomatic patients with accessory atrioventricular pathways in all locations.

Cardioverter discharges following sensing of electrical artifact due to fluid penetration in the connector port.

We report a unique case of fluid penetration, 3 months after implantation, in the connector port of an automatic implantable cardioverter defibrillator (ICD) with transvenous subcutaneous lead system. The patient had coronary artery disease and recurrent episodes of ventricular fibrillation, the fluid caused electrical signals interpreted as ventricular fibrillation by the device, which triggered shock delivery.

[Location of atrial and ventricular insertions of accessory atrioventricular pathways using surface ECG mapping and its importance in catheter ablation therapy]. / Lokalizácia predsienovej a komorovej inzercie akcesórnych átrioventrikulárnych dráh pomocou povrchového ekg mapovania a jej význam pre liecbu katétrovou abláciou.

BACKGROUND: The modern non-pharmacological therapy of the WPW syndrome by means of catheter ablation is based on the interruption of the accessory pathway(-s) by radiofrequency current energy. Destruction of the morphologic substrate of the arrhythmia alters the activation wave spread in the heart. OBJECTIVES: It was the aim of this report to demonstrate the diagnostic potential of BSM in localizing both overt and concealed accessory pathways. Presented study analyzes the alterations of the cardioelectric field by means of body surface ECG mapping in two female patients with accessory pathways before and after their successful curative treatment by radiofrequency catheter ablation. METHODS: Five patients were analyzed prior and after RF catheter ablation by BSM, two of them were selected for this presentation. One patient with WPW syndrome suffered from frequent supraventricular tachycardia due to in one female patient with an overt accessory pathway. The other patient was for several years incessantly in permanent junctional reentry tachycardia due to a concealed accessory pathway. The examination comprised 12-lead ECG, orthogonal vectorcardiogram according to Frank, BSM using a regular 80-electrode-array system and signal-averaged ECG. RESULTS: The RF ablation was successful in both patients and their arrhythmia was abolished. By means of a detailed analysis of the ventricular activation prior RF ablation in the patient with WPW syndrome the precise site of the ventricular insertion of the accessory pathway in the left lateral free wall was predicted. Furthermore, alterations of the terminal QRS complex were observed when comparing pre- versus post-ablation maps. In the second patient the atrial insertion of the accessory pathway with retrograde and decremental conduction was successfully localized to the right septal region by means of pre-ablation BSM. CONCLUSIONS: Both ventricular and atrial activation can be in detail analyzed by means of BSM. Such analysis offers more precise information on the spatial component of the activation wave spread. This case report gives further evidence that BSM is a useful method for precise localization of both ventricular and atrial insertion sites of accessory pathways in patients with paroxysmal tachycardias due to this electrophysiologic abnormality. This information gained recently clinical impact since it can be directly used for faster arrhythmogenic substrate targeting during ablation therapy. (Fig. 5, Ref. 17.)

[Efficacy of the implantable cardioverter-defibrillator in patients on the waiting list for heart transplantation]. / Effizienz des implantierbaren Cardioverter-Defibrillators bei Patienten auf der Warteliste zur Herztransplantation.

8 of 122 patients receiving an implantable cardioverter defibrillator (ICD) in our department since 1985 for the treatment of ventricular tachyarrhythmias were considered candidates for cardiac transplantation. In 6 of 8 patients, at least one successful ICD discharge (range 1-378 discharges) was documented in the follow up time until transplantation. These therapies included cardioversions/defibrillations as well as overdrive stimulation in sustained monomorphic ventricular tachycardia. 1 patient died shortly before receiving a compatible organ. The remaining 7 patients survived successful heart transplantation undertaken 7-34 months after implantation of the cardioverter defibrillator. Cardiac transplantation was not complicated in any of these patients by the previous ICD management. Our results show the high efficacy of ICD as "bridge to transplant" therapy unit cardiac transplantation.

[Complications in transvenous and transvenous-subcutaneous implantable defibrillator systems]. / Komplikationen bei transvenös bzw. transvenös-subkutan implantierbaren Defibrillatorsystemen.

Due to technical improvement using the transvenous-subcutaneous approach for lead fixation for cardioverter-defibrillator implantation, the incidence of device implantation has extended enormously. While a significant lower perioperative mortality in transvenously implanted systems compared to epicardially fixed implantable cardioverter-defibrillator (ICD) has been proven, perioperative as well as complications during follow-up are not analyzed systematically. In 59 patients, in whom transvenous-subcutaneous ICDs had been implanted, 3 patients showed bleeding complications in the subcutaneous patch area, 1 patient showed a bleeding in the device pocket, and in 1 patient a seroma in the subcutaneous patch region was observed necessitating surgical revisions. During follow-up of 10 +/- 7 months, lead dislocations were observed in 6 patients, in another 6 patients patch crinkling was observed. There was 1 patient with a lead fracture as well as 1 patient with a bleeding in the subcutaneous patch region. Despite the high efficacy of this therapy used in patients with life-threatening ventricular arrhythmias, these potential complications have to be considered.

Hemodynamics during ventricular tachyarrhythmias.

The hemodynamic consequences of ventricular tachycardias are caused by cardiac and peripheral reactions. As a result, cardiac output and arterial pressure decrease. Even if the decrease is related to the tachycardia rate and left ventricular function, clinical symptoms do not in each case correlate with the degree of hemodynamic compromise. The explanation for this phenomenon is the different cardiac and peripheral reaction of patients to an immediate rise in heart rate. In this regard, it is questionable if pressure monitoring is superior to heart rate monitoring as a sensor for implantable antitachycardia devices.

[Therapy monitoring in cardiac arrhythmias: guidelines for evaluation of anti-arrhythmia effects]. / Therapiekontrolle bei Herzrhythmusstörungen: Richtlinien zur Prüfung antiarrhythmischer Wirkungen.

The incidence of avoidable or unavoidable, cardial and extracardial side effects is a risk in the drug treatment of supraventricular and ventricular tachyarrhythmias. Therefore the indication of antiarrhythmic drug therapy has to be considered critically. The patient has to be controlled close-meshed, especially at the beginning of the drug treatment. In patients with life threatening ventricular tachyarrhythmias, which can not be suppressed by drug therapy, nonpharmacological therapy--implantable cardioverter/defibrillator, catheterablation and heart-transplantation--has to be discussed.

[Electrocardiography and electrophysiologic findings in patients with myotonic muscular dystrophy]. / Elektrokardiographische und elektrophysiologische Befunde bei Patienten mit myotoner Muskeldystrophie.

Myotonic dystrophy is associated with diffuse cardiac conduction disturbances. Seven consecutive patients, all asymptomatic with respect to cardiac abnormalities, were investigated by means of ECG, Holter monitoring, and invasive electrophysiologic studies (EPS). During Holter monitoring, no abnormalities were found in any patient, except for one patient who showed single monomorphic VEBs. During EPS three patients showed conduction disturbances in the AV-node (AVN) as well as in the His-Purkinje-system (HPS) in another three patients. Except for two patients ventricular vulnerability was normal during programmed ventricular stimulation. A considerable number of asymptomatic patients with myotonic dystrophy reveals AVN- and HPS-conduction disturbances as shown during EPS.

[Implantation of defibrillators with transvenous-subcutaneous electrode systems]. / Implantation von Defibrillatoren mit transvenös-subkutanem Elektrodensystem.

In 23 patients an integrated pacemaker-defibrillator-system with transvenous-subcutaneous lead system was implanted. Two transvenous electrodes were positioned, one in the right ventricle for sensing, pacing and defibrillation and one in the superior vena cava for defibrillation alone. Another electrode was positioned subcutaneously near the ventricular apex for defibrillation. In 22 patients (96%) the lead system could be implanted without a major complication. The defibrillation threshold for ventricular fibrillation was 16 +/- 5 joules. During follow up of 6 +/- 4 months all spontaneous tachyarrhythmias were successfully terminated. There were three complications during follow up. In 2 patients the transvenous electrode dislocated and one patient showed a sensing malfunction. In conclusion the non-thoracotomy approach is effective, reduces the perioperative risk and represents therefore a great advantage compared to peri-/epicardial lead system.

[Value of a provocation test with diprafenone in patients with bifascicular block]. / Stellenwert eines Provokationstestes mit Diprafenon bei Patienten mit bifaszikulärem Block.

The significance of provocative tests in patients with bifascicular block is not established. We studied 14 patients with bifascicular block, syncope and documented episodes of high degree AV-block. 1.5 mg/kg Diprafenon was given after a period of at last 12 hours 1:1 AV-conduction. Electrophysiologic evaluation was performed before and after diprafenon. AV-block III could be provoked in 1 of 14 patients with Diprafenon. Therefore a total AV block occurred in 7% of patients. The low sensitivity of provocative test with Diprafenon even in patients with documented high degree AV-block prevents its application in clinical practice.

Efficacy and electrophysiologic effects of oral sotalol in patients with sustained ventricular tachycardia caused by coronary artery disease.

The efficacy of oral sotalol in preventing sustained ventricular tachycardia induction by invasive electrophysiological testing was assessed in 22 patients (60 +/- 9 years) with prior myocardial infarction. Programmed stimulation consisted of two basic drives followed by up to three extrastimuli at two right ventricular sites. At baseline, sustained monomorphic ventricular tachycardia was inducible in all patients. With sotalol (360 +/- 172 mg/day), it was no longer inducible in 10 patients; in 12 others, it remained inducible and its cycle length was only minimally prolonged (322 +/- 42 to 345 +/- 44 msec, p less than 0.05). Sotalol markedly prolonged sinus cycle length, uncorrected QT interval, and right ventricular effective and functional refractory periods, but had little effect on ventricular conduction time either in sinus rhythm or with right ventricular pacing. There was no significant difference in drug dose or in electrophysiologic effect of drug that related to efficacy, nor was there any correlation between drug-induced prolongation of ventricular tachycardia cycle length and its effects. Six patients received oral sotalol over the long term without spontaneous recurrence of ventricular tachycardia (follow-up: 23 +/- 18 months). These results demonstrate that sotalol is effective (45%) against sustained ventricular tachycardia induction at moderate doses and is well tolerated over a long term in the setting of remote myocardial infarction. However, its electrophysiologic effects as measured at invasive testing are not predictive of efficacy against ventricular tachycardia induction.

[Non-drug therapy of ventricular tachycardia/ventricular fibrillation]. / Nichtmedikamentöse Therapie von Kammertachykardie/Kammerflimmern.

In the majority of patients with ventricular tachycardia/fibrillation drug treatment is not effective. The non-pharmacological treatment of this high-risk patients is of increasing importance. In Austria about 900 patients per year need non-pharmacological treatment of malignant ventricular arrhythmias. For this purpose 4 or 5 specialized centers would be necessary.

Epicardial and endocardial mapping of ventricular tachycardia in patients with myocardial infarction. Is the origin of the tachycardia always subendocardially localized?

BACKGROUND: Left ventricular endocardial reentry is the conventional concept underlying surgery for ventricular tachycardia (VT). We assessed the incidences of patterns showing complete reentry circuits at either the subendocardial or subepicardial level and of patterns in which left ventricular endocardial mapping could only in part account for a reentrant mechanism. METHODS AND RESULTS: We retrospectively analyzed epicardial and left ventricular endocardial isochronal maps of 47 VTs induced in 28 patients with chronic myocardial infarction (inferior, 14 patients; anteroseptal, 14 patients). Electrograms were recorded intraoperatively from 128 sites with epicardial sock and transatrial left ventricular endocardial balloon electrode arrays. Given the methodology used in this study, the mapping characteristics of the tachycardias suggested five types of activation patterns: 1) complete (90% or more of VT cycle length) subendocardial reentry circuits in seven VTs (15%) and seven patients (25%), 2) complete subepicardial reentry circuits in four VTs (9%) and four patients (14%), 3) incompletely mapped circuits with a left ventricular endocardial breakthrough preceding the epicardial breakthrough in 25 VTs (53%) and 21 patients (75%), 4) incompletely mapped circuits with a left ventricular epicardial breakthrough preceding the endocardial breakthrough in three VTs (6%) and three patients (11%), and 5) a right ventricular epicardial breakthrough preceding the left ventricular endocardial breakthrough in eight VTs (17%) and seven patients (25%). After surgery, one type 3 VT and three type 5 VTs were reinducible. Thus, left ventricular endocardial reentry substrates (types 1 and 3) accounted for 68% of VTs, but substrates involving subepicardial (types 2 and 4) and deep septal layers (type 5) accounted for 32% of VTs. CONCLUSIONS: In a substantial number of VTs, a substrate localization that is at variance with the conventional concept can be detected by simultaneous epicardial and endocardial mapping and may require modification of the surgical approach conventionally aimed at endocardial layers.

Surgical treatment of the Wolff-Parkinson-White syndrome. Endocardial versus epicardial approach.

From 1983 to 1988, 51 patients with the Wolff-Parkinson-White syndrome underwent surgical ablation of an accessory conduction pathway, 25 by the classic endocardial approach and 26 by the epicardial technique supplemented by cryosurgery. In the endocardial and epicardial groups, the accessory pathway was in the left free wall in 22 and 18 patients, respectively, posterior septal in two and seven, and in the right free wall in one patient in each group. There was no early or late death in the endocardial group, and postoperative complications developed in five patients (20%). Pathway ablation was completely successful in 22 patients (88%), preexcitation recurred in two patients (8%), and one had recurrence of supraventricular tachycardia (4%). One of the failures occurred with a posterior septal pathway (50%), and the two others with a left free-wall pathway (9%). With the epicardial technique, there were no early deaths and one late death caused by atherosclerotic coronary artery disease. Five patients (19%) had postoperative complications. The pathway was ablated successfully in 22 patients (85%), preexcitation recurred in three patients (12%), and supraventricular tachycardia remained inducible in another patient despite disappearance of the delta wave. Three of those failures occurred with anterior left free-wall pathways (16%), but only one patient had recurrent supraventricular tachycardia (4%) requiring immediate reoperation, which was successful. In conclusion, although epicardial or endocardial approaches produced similar results, our observations suggest that left free-wall accessory pathways located high anteriorly may be ablated in a more reproducible way with the endocardial technique, whereas the epicardial approach appears easier for posterior septal pathways. We therefore believe that any surgeon beginning such surgery should be aware of the possibilities and limitations of each of the two techniques.

[The origin of late potentials in patients with ventricular tachycardia after myocardial infarction]. / L'origine des potentiels tardifs chez les patients ayant des tachycardies ventriculaires après infarctus du myocarde.

In order to study the origin of late potentials, their distribution was analyzed in 16 patients who had undergone surgery for arrhythmia due to ventricular tachycardia following myocardial infarction. The potentials were measured in sinus rhythm using 63 unipolar leads placed on the chest before the operation, then on the epicardium and endocardium during the operation. Epicardial and/or endocardial activity extending beyond the QRS complex measured from unfiltered chest signals and characterized by slowed propagation at the edge or inside of necrotic regions, stable from one beat to the next, and showing simple (39 per cent), double (34 per cent) or fragmented (27 per cent) deflections on the electrocardiograms were observed in 5/6 patients without bundle-branch block and in 5/10 patients with block. Similar activity but which did not extend after the QRS was detected in the 6 other patients. For signals filtered at 55 Hz, a close correlation between the distribution of chest, epicardial and endocardial potentials was observed, thus allowing approximate location of the origin of late potentials from the chest. Anterior or apical sites corresponded to close extrema in the precordial region, whereas the other sites were associated with more distant extrema. An analysis of potential distribution thus gives a better understanding of the electrogenesis of late potentials as well as their detection on the chest.

Spatial domain analysis of late ventricular potentials. Intraoperative and thoracic correlations.

For investigation of late potentials seen on the signal-averaged electrocardiogram, intracardiac and thoracic distributions of terminal activity were analyzed in 16 patients undergoing cryosurgery for ventricular tachycardia after remote myocardial infarction. The body surface potentials measured with 63 time-averaged unipolar leads were compared with epicardial and endocardial potential maps in six patients without and 10 patients with bundle-branch block. Intracardiac post-QRS activity, defined as extending beyond the thoracic QRS offset, was found in five of six patients without bundle-branch block (83%) and in five of 10 patients with bundle-branch block (50%), corresponding to 4 +/- 5% of the total number of electrograms in each patient. Fragmentation, double deflections, and single deflections were observed in 27%, 34%, and 39%, respectively, of these post-QRS electrograms. Post-QRS activation patterns that were stable from beat to beat showed slow propagation around or within areas of conduction block. Post-QRS activity was most often observed on both epicardial and endocardial surfaces (five of 10 patients). In the six patients without post-QRS activity, an area of late activity displaying low-amplitude deflections that were masked by the terminal activation of the normal myocardium was identified. Isopotential maps of the high-pass-filtered (55-Hz) thoracic and intracardiac signals demonstrated a close spatial correlation between the location, amplitude, and orientation of the potential extrema observed over the thoracic, epicardial, or endocardial surfaces during post-QRS activity. The thoracic patterns were generally dipolar with close extrema for anteroseptal or apical sites of post-QRS activity and more distant extrema for other sites.(ABSTRACT TRUNCATED AT 250 WORDS)