Two year follow-up in 643 patients with non-invasively unexplained syncope and therapy guided by electrophysiologic study.

AIM: Although it has become standard practice to perform electrophysiologic studies in patients with unexplained syncope, limited information exists on prognosis after therapy guided by electrophysiologic studies. METHODS AND RESULTS: Electrophysiologic studies were performed in 643 patients with unexplained syncope. Electrophysiologic studies revealed conduction abnormalities and tachyarrhythmias accounting for syncope in 35% of patients. An ejection fraction 2 s and injury are helpful parameters in predicting a positive electrophysiologic study. There was no difference regarding cumulative 2-year survival rate after therapy guided by positive electrophysiologic study compared to patients with negative electrophysiologic study. The cumulative 2-year survival free-of-syncope rate was significantly higher after therapy guided by electrophysiologic study compared to patients with negative electrophysiologic findings-for patients with organic heart disease (71.3% vs 48.5%, p < 0.001) and patients without disease (91.3% vs. 65.2%, p < 0.001). Using a logistic regression model, a positive electrophysiologic study was associated with a favorable outcome; multiple syncopal events or organic heart disease were associated with an unfavorable outcome. CONCLUSION: The cumulative overall 2-year surival free-of-syncope rate is significantly higher in patients after therapy guided by electrophysiologic study compared to patients with negative electrophysiologic findings.

[Catheter-based rescue of a split pacemaker lead in the pulmonary artery]. / Kathetertechnische Bergung der Innenwendel einer separierten Schrittmacher-Elektrode in der Arteria pulmonalis.

This case report describes a successful catheter-based rescue of a split pacemaker lead in the pulmonary artery-as an unusual reason for pleural effusion. Hemorrhagic pleural effusion was diagnosed 7 months after pacemaker exchange due to battery depletion and lead replacement due to an increase of the stimulation threshold. The reason for the pleural effusion was a splitting of the inactive electrode lead into shaft and inner fragment which was dislocated into the pulmonary artery and micro-perforated. The dislocated lead was retrieved using biopsy forceps and a gooseneck snare. Finally it was capped and fixed. Even in an anatomically difficult position, catheter-based rescue is feasible. Not in all pacemaker lead types is cutting the adapter of the inactive pacemaker leads recommendable.

Usefulness of a non-invasive scoring system in predicting the outcome of electrophysiologic studies in non-invasively unexplained syncope.

BACKGROUND: An electrophysiologic study is a useful method to clarify the cause of non-invasively unexplained syncope in 18-60% of patients. However, it is invasive with possible procedure-related complications. Therefore, it would be helpful to identify patients in whom an electrophysiologic study is useful for diagnosis of syncope. METHODS: Patients with unexplained syncope were prospectively enrolled in a registry, if an electrophysiologic study was performed. The study group comprised of 643 consecutive patients. RESULTS: The electrophysiologic study revealed conduction abnormalities and tachyarrhythmias accounting for syncope in 35% of patients. Using a logistic regression model, history of injury during syncope (p<0.001), ejection fraction < or =40% (p=0.03), and PR interval >0.2 s (p=0.001) were independent predictors of an abnormal electrophysiologic study. These three clinical and easily measurable variables were entered into a scoring system. The maximal score consisted of 3 points. A score of >1 predicts a positive electrophysiologic study result in more than 70% of patients with non-invasively unexplained syncope. CONCLUSION: Electrophysiologic abnormalities were detected in 35% of patients with unexplained syncope. A history of injury, ejection fraction < or =40% and a PR interval >200 ms were independent predictors for a positive electrophysiologic study.

Prognostic value of non-sustained ventricular tachycardias after acute myocardial infarction in the thrombolytic era: importance of combination with frequent ventricular premature beats.

PURPOSE: of this study was to re-evaluate the association between ventricular arrhythmias and long-term mortality after acute myocardial infarction (AMI) in the thrombolytic era. METHODS: MITRA (maximal individual therapy in patients with AMI) is a multicenter registry of 54 hospitals in Germany investigating patients with AMI. RESULTS: 2420 patients received Holter ECG. Positive Holter ECG was defined: > or =10 ventricular premature beats (VPB)/h, or > or =4 couplets/d, or > or =1 non-sustained ventricular tachycardia (nsusVT)/d, or their combination. Mortality rates (median 17 months) were 6.5% without ventricular arrhythmias, with > or =10 VPB/h 15.2% and with the combination of > or =10 VPB/h plus either > or =4 couplets/d or > or =1 nsusVT/d 23.4%. In multivariate analysis, none of the ventricular arrhythmias alone correlated with mortality. There was a significant association between mortality and the combination of > or =10 VPB/h plus > or =4 couplets/d (OR 2.3) or > or =10 VPB/h plus > or =1 nsusVT/d (OR 2.8). CONCLUSION: Non-sustained VTs are only associated with poor prognosis if combined with frequent VPBs.

[Catheter ablation of ventricular tachycardia in the left ventricular outflow tract beyond the aortic valve]. / Katheterablation einer Kammertachykardie im linksventrikulären Ausflusstrakt oberhalb der Aortenklappe.

This case report describes successful catheter ablation of an ectopic focus in the left ventricular outflow tract just beyond the aortic valve. Extended pace-mapping revealed a focus about 1 cm beneath the origin of the left coronary artery--above the base of the left coronary cusp. During a follow-up of 1 year no further spontaneous episode of ventricular tachycardia was documented. This case report describes an unusual localization of an idiopathic ventricular tachycardia and it demonstrates that radiofrequency catheter ablation can be done even in a critical position.

[2 year follow-up of 321 patients with an implantable cardioverter/defibrillator: comparison of patients with and without atrial fibrillation]. / Verlaufsbeobachtung von 2 Jahren bei 321 Patienten mit einem implantierbaren Kardioverter/Defibrillator: Vergleich zwischen Patienten mit und ohne Vorhofflimmern.

UNLABELLED: Atrial fibrillation is the most common cause of inappropriate therapy deliveries by implantable cardioverter/defibrillators (ICD). However, the importance of atrial fibrillation for the induction of ventricular arrhythmias and for the prognosis is controversial. We studied 321 ICD patients (pts) over the median follow-up of 25 months. In 92 pts, atrial fibrillation was found to be the underlying rhythm (in 49 pts chronic, in 43 pts paroxysmal), in 229 pts sinus rhythm. Pts with atrial fibrillation were older (67 +/- 9 vs. 63 +/- 9 years, p = 0.001) and were considered to suffer more often from a valvular (14 vs. 4%, p = 0.004) or a dilative cardiomyopathy (29 vs. 19%, p = 0.04). Both groups were similar regarding other baseline characteristics like gender, left ventricular ejection fraction, hypertension, diabetes and in the ICD system (single chamber, dual chamber) used. Pts with atrial fibrillation experienced more appropriate (ventricular fibrillation: 0.33 vs. 0.2/month, p = 0.0049, ventricular tachycardias: 0.05 vs 0/month, p = 0.0033) as well as inappropriate (34 vs. 8%, p < 0.001) therapy deliveries by the ICD. Pts with atrial fibrillation were found to suffer twice as much from a progression of their heart failure (43% vs. 22%, p < 0.001). After multivariate analysis, atrial fibrillation was significantly associated with progressive pump-failure mortality (relative risk (RR) 3.12, confidence interval (CI) 1.30 to 7.48, p = 0.01). There was no difference in the incidence of ICD therapies and mortality rates between the pts with chronic and paroxysmal atrial fibrillation. CONCLUSION: The presence of atrial fibrillation in ICD patients is associated with a progression of heart failure and therefore is an unfavorable factor for pump-failure death. Also, atrial fibrillation is a marker for greater possibility to experience more appropriate as well as inappropriate therapy deliveries by the ICD.

[Initial experience with an implantable loop recorder in patients with unexplained syncope]. / Erste Erfahrungen über den diagnostischen Nutzen eines implantierbaren Langzeit-Ereignisrekorders (Endless-Loop-Rekorder, REVEAL((R))) bei Patienten mit unklaren Synkopen.

Patients with recurrent syncope undiagnosed after extensive noninvasive and invasive testing pose a diagnostic and therapeutic dilemma. Holter monitoring is non-diagnostic in 90% of cases. Recent developments in loop recorder technology permit longterm ECG monitoring in patients with recurrent unexplained syncope. The implantable loop recorder monitors a single lead electrogram continuously using 2 sensing electrodes on the device shell. The device was implanted in 20 patients (11 male, 9 female) with the history of recurrent syncope. During a mean follow-up of 12+/-6 months after device implantation, 11 patients (55%) experienced syncope (8 pts) or presyncope (3 pts). In the remaining 9 patients, no syncope occurred. In all 11 patients with syncope or presyncope during follow-up, loop recording definitively determined whether an arrhythmia was the cause of symptoms or not. Diagnosis included bradycardia in one patient, tachycardia in two patients, in one patient two rhythm disturbances were revealed: frequent ventricular premature beats with bigemini and atrial flutter. Two patients had a neurocardiogenic syncope. Syncope was nonarrhythmic in 5 patients. An implantable loop recorder is useful for establishing the diagnosis if symptoms are recurrent but too infrequent for conventional monitoring techniques.

[Lead-related complications in 340 patients with an implantable cardiverter/defibrillator]. / Komplikationen mit Sonden bei 340 Patienten mit einem implantierbaren Kardioverter/Defibrillator.

From February 1991 to May 1998, 340 patients had a cardioverter/defibrillator (ICD) implanted. Mean age was 64 +/- 9 years, 278 male and 62 female. 60% of patients had coronary artery disease and 31% dilatative cardiomyopathy. Ejection fraction was 38 +/- 14%. The indication for an implantable cardioverter/defibrillator was in 57% of patients ventricular tachycardia, in 43% ventricular fibrillation. 298 patients had a single-chamber cardioverter/defibrillator implanted, 42 patients a dual-chamber cardioverter/defibrillator. In 25 patients additional subcutaneous patch or array electrodes and in 2 patients additional epicardial patch electrodes were implanted. Implantation site was in 92 patients abdominal and in 248 pectoral. Over a period of 7 years 34 lead-related complications occurred in 33 patients (9.7%), after a median of 2 months after implantation. Diagnosis was made by routine chest x-ray in about 55% of lead-related complications, by clinical presentation (inadequate therapy, pain) in 24%, and by electrical parameters in 21%. In patients with an abdominal implantation site, lead-related complications occurred in 20%, in contrast to 6% in patients with a pectoral implantation site. Regarding patients with pectoral implantation site, lead-related complications were observed in 12% of patients with a dual-chamber ICD vs 4% with a single-chamber ICD (p = 0.05), due to dislocation of atrial electrodes with dual-chamber ICD. There were no differences in clinical parameters between patients with pectoral vs abdominal and between single vs dual-chamber ICD. There were no deaths due to lead-related complications.

[Clinical experience with the implantable atrial defibrillator (atrioverter) in patients with atrial fibrillation. Metrix Investigators]. / Klinische Erfahrungen mit dem implantierbaren atrialen Defibrillator (Atrioverter) bei Patienten mit Vorhofflimmern. Metrix Investigators.

Due to the limited efficacy of drug therapy in atrial fibrillation and the high rate of recurrence, strong efforts were made to find non-pharmacological strategies. For three years now, the implantable atrial defibrillator Metrix from InControl has been available as an alternative therapy. From October 1995 to the present the atrial defibrillator was implanted in 179 patients worldwide. The sensitivity of the system and its algorithms to detect atrial fibrillation is 90%; the specificity to detect sinus rhythm is 100%. In 121 of 179 patients, 748 episodes of spontaneous atrial fibrillation were treated with 2.4 shocks per episode. No proarrhythmic event or stroke was seen. A cardioversion to sinus rhythm could be achieved in 95% of patients; the overall clinical success rate was 88%. In 7% of all patients, early recurrence of atrial fibrillation (ERAF) occurred that could not be converted into stable sinus rhythm after further cardioversions and antiarrhythmic therapy. In 4.1% there were lead-related complications, in 4 patients the device had to be explanted because of ineffective therapy, and in 3 patients the device had to be changed because of loss of telemetry or early depletion of battery. In 8 patients, postoperative complications were seen (infections, pneumothorax and thrombosis of the subclavian vein). Overall, the implantable atrial defibrillator Metrix is an effective and safe alternative in treating atrial fibrillation.

Radiofrequency catheter ablation of frequent monomorphic ventricular ectopic activity.

INTRODUCTION: Frequent ventricular ectopic beats can result in severe symptoms and may even be incapacitating in some patients. Although radiofrequency catheter ablation is an effective and safe therapy for drug refractory idiopathic ventricular tachycardia, it has not been widely used in ventricular ectopy. The purpose of this study was: (1) to assess the potential role of catheter ablation in eliminating monomorphic ventricular ectopy in symptomatic patients regarding feasibility and safety and (2) to determine the usefulness of various mapping strategies. METHODS AND RESULTS: Forty-one patients with symptomatic ventricular ectopic activity (right ventricular origin in 23 patients, left ventricular origin in 18 patients) were enrolled. The mean frequency of ventricular ectopic beats was 1512+/-583/hour documented by Holter ECG monitoring. These patients had previously been unable to tolerate or had been unsuccessfully treated with a mean of 3+/-1 antiarrhythmic agents. The site of origin was mapped using earliest endocardial activation times, unipolar electrograms and pace mapping. Radiofrequency ablation was successful in 34 (83 %) of 41 patients. Multivariate logistic regression analysis revealed pace mapping as the only independent predictor for a successful ablation site (P < 0.01). After a follow-up of 3 months, the overall success rate was 71%. The mean frequency of ventricular ectopic beats after successful ablation was 12+/-10 ventricular premature beat/hour. CONCLUSION: Radiofrequency catheter ablation is an effective and safe treatment for frequent symptomatic drug refractory monomorphic ventricular ectopic activity. Pace mapping predicts best successful ablation of ventricular ectopic beats.

[Pseudoaneurysm in the vicinity of the ascending aorta caused by contained disruption at the insertion site of a coronary artery bypass graft. A case report]. / Pseudoaneurysma im Bereich der Aorta ascendens bei gedeckter Perforation am Abgang eines koronaren Venen-Bypasses. Ein Fallbericht.

In this case report a 65-year-old patient came into the emergency ward with acute chest pain after coronary artery bypass graft operation in 1985. On routine chest X-ray in 1995 a mediastinal widening was diagnosed. The chest X-ray in 1997 (Figure 1) showed an increase of the diameter of the known mediastinal widening. Therefore a CT-scan was performed (Figures 2a and 2b). This showed an enhancement of contrast material in a contained structure, without identifying its origin. Therefore a coronary angiography was done. Here, we diagnosed a contained disruption of the aorta at the insertion site of the bypass graft at the right coronary artery. Figure 3a shows leakage of contrast material out of the aorta into the pseudoaneurysm and in Figure 3b this is demonstrated in a schematic drawing. Figure 4a shows supraselective imaging of the pseudoaneurysm, demonstrated in a schematic drawing in Figure 4b. As the chest pain could only be handled by i.v.-medication, betablocker and bed rest we decided to operate. Intra-operatively the diagnosis was confirmed (Figure 5a and 5b). Postoperatively the patient died due to cerebral ischemia. Despite the lethal outcome an operative revision appears even retrospectively justified because of the increasing size of the pseudoaneurysm in addition to new symptoms that were difficult to treat. On the other hand there are no data available in order to estimate the risk of a spontaneous course.

Importance of preimplantation procedures in candidates for an implantable atrial defibrillator.

INTRODUCTION: Due to the limited efficacy of antiarrhythmic drugs for the treatment of atrial fibrillation, several nonpharmacologic therapeutic options have been developed. One of these options is an implantable atrial defibrillator for patients with severe symptoms and infrequent drug-refractory episodes of atrial fibrillation. The purposes of this study were: (1) to evaluate how many patients with atrial fibrillation are possible candidates for an implantable atrial defibrillator; and (2) to report the results and findings of preimplantation testing in a single center. METHODS AND RESULTS: From our atrial fibrillation outpatient clinic, we evaluated the number of possible candidates for an atrial defibrillator using the following criteria: (1) recurrent persistent atrial fibrillation; (2) long-lasting but infrequent episodes; (3) refractory to antiarrhythmic drugs; (4) capability of maintaining normal sinus rhythm; and (5) no factors increasing proarrhythmic risk. In those patients eligible for an atrial defibrillator, a separate preimplantation test was performed to evaluate atrial defibrillation limits and patient acceptance. Thirty-one of 196 patients were possible candidates for an atrial defibrillator. Fourteen of these 31 patients agreed to participate in the METRIX clinical study phase I on atrial defibrillators. Six of these patients met implantation criteria; two patients refused permanent implantation because of intolerable pain. Implantation was performed in four patients; however, one patient could not be cardioverted intraoperatively despite a successful preimplantation test. CONCLUSION: About 16% of selected patients with atrial fibrillation are possible candidates for an atrial defibrillator. However, successful preimplantation testing does not exclude implantation failure.

Ca(++)-dependent constitutive nitric oxide synthase is not involved in the cyclic GMP-increasing effects of carbachol in ventricular cardiomyocytes.

We investigated the effects of the M-cholinoceptor agonist carbachol on cyclic GMP (cGMP) content and contractile response in the absence and presence of the nitric oxide synthase inhibitor NG-nitro-L-arginine in guinea-pig isolated ventricular cardiomyocytes. Carbachol (10 mumol/l, 10 min) increased basal cGMP content to approximately 200% and contractile response to 118%. Preincubation of the cardiomyocytes with NG-nitro-L-arginine (0.1 mumol/l, 60 min) did not alter the effects of carbachol on neither cGMP content or contractile response. Moreover, nitric oxide synthase activity was undetectable in crude or ADP-agarose purified cytosolic and particulate fractions of homogenized isolated ventricular cardiomyocytes. Pretreatment with pertussis toxin did not affect the carbachol-mediated increase in cGMP content or contractile response. However, methylene blue abolished the elevation in cGMP content by carbachol, without changing contractile response. It is concluded that the carbachol-mediated increase in cGMP content and contractile response in ventricular cardiomyocytes is neither mediated via a nitric oxidebiosynthesis pathway nor via a pertussis toxin-sensitive GTP-binding protein. Furthermore, the cGMP increase by carbachol is due to an activation of soluble guanylyl cyclase and is dissociated from the contractile response. We therefore assume that carbachol activates two independent effector cascades, one leading to an elevation in cGMP content and the other to an increase in contractile response and that none of the effects are mediated via endogenous nitric oxide formation.