Biomedical subjects

M Rameken

Publications and source records attributed to M Rameken.

8 recordsLinked to original sources

PubMed2003

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.

Adult↗

PubMed2003

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 </= 40%, a PR-interval > 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.

Adult↗

PubMed2002

[Long-term outcome of AV node modulation in 387 consecutive patients with AV nodal reentrant tachycardia].

UNLABELLED: Aim of this study was to assess the long-term results of AV-node modulation in patients with AV nodal reetrant tachycardia. METHODS: From December 1991 until September 1999, AV node modulation (ablation of the fast pathway or ablation/modification of the slow pathway) was performed in 387 consecutive patients with clinically apparent AV nodal reentrant tachycardia. Follow-up data was available in 95% of patients with a mean of 41 +/- 26 months after ablation. RESULTS: Acute success rate was 97%. During long-term follow-up recurrence rate was 7.4% without any difference between fast and slow pathway ablation. Recurrence occurred in 23% of patients with persistent dual AV node physiology after ablation (modification of the slow pathway) in contrast to 3% without dual AV node physiology (ablation of the slow pathway) (p = 0.002). The presence of a dual AV node physiology after slow pathway modulation was the only predictor of recurrence during long-term follow-up. The complication rate was 5.7%. The incidence of complete heart block was 1% without any difference between fast and slow pathway ablation. CONCLUSIONS: Catheter modulation of the AV node for the treatment of AV nodal reentrant tachycardia is effective and safe. During long-term follow-up, the recurrence rate was low. Modulation of the slow pathway is associated with a significantly higher recurrence rate than ablation of the slow pathway.

Adult↗

PubMed2002

Biventricular pacing in patients with ICD: how many patients are possible candidates?

BACKGROUND: About 80 % of patients receiving an implantable cardioverter-defibrillator (ICD) due to life-threatening episodes of ventricular tachycardia (VT) or ventricular fibrillation (VF) have structural heart disease. ICD implantation reduces the risk of sudden cardiac death to less than 2 %. However, the major obstacle in these patients is chronic heart failure (CHF). Biventricular stimulation (BIV) has shown its efficiency as an alternative therapy in drug refractory CHF. METHODS: According to the InSync registry, we predefined possible indications for BIV as follows: complete branch bundle block (> 120 ms), left-ventricular ejection fraction (EF) < 35 % and NYHA class > II. We evaluated the number of patients presenting this indication at time of implant and during follow-up (FU) at our ICD clinic. RESULTS: Between 1992 and 1998, 360 patients were provided with an ICD (mean age 64.6 +/- 5.4 yrs, mean EF 37 +/- 14 % at implant, 82 % of patients with organic heart disease). Mean FU was 34 +/- 21 months. During FU 46 patients (13 %) died, 15 of these (33 %) presenting criteria for BIV. 33 patients died of heart failure, there was 1 sudden death and 12 patients died for non-cardiac reasons. 35 % of the patients who died of heart failure had an indication for BIV. CONCLUSIONS: About 10 % of ICD patients had an indication for BIV at time of implant. Over a mean FU period of 34 months, 16% of all patients presented an indication for BIV. Patients with an indication for BIV had a higher mortality rate and more frequent atrial fibrillation compared to patients without. With this data and the good clinical results after BIV-ICD implantation, we consider the implantation of a BIV-ICD system in every patient with appropriate indications.

Aged↗

PubMed2001

[2 year follow-up of 321 patients with an implantable cardioverter/defibrillator: comparison of patients with and without atrial fibrillation].

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.

Aged↗

PubMed2000

[Initial experience with an implantable loop recorder in patients with unexplained syncope].

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.

Aged↗

PubMed2000

Diagnostic assessment of recurrent unexplained syncope with a new subcutaneously implantable loop recorder. Reveal-Investigators.

AIM: Patients with recurrent syncope undiagnosed after extensive non-invasive and invasive testing pose a diagnostic and therapeutic dilemma. Holter monitoring is nondiagnostic in 90% of cases. Recent developments in loop recorder technology permit long-term ECG monitoring in patients with recurrent unexplained syncope. The aim of this study was to report the worldwide experience with a new subcutaneously implantable loop recorder, implanted in 133 patients with unexplained syncope and negative laboratory investigations. METHODS AND RESULTS: The implantable loop recorder monitors continuously a single lead electrogram using two sensing electrodes on the device shell. The device was implanted in 133 patients, 67 male and 66 female with recurrent syncope. During a mean follow-up of 10.8 +/- 4.3 months after device implantation, 83 patients (62%) experienced syncope or pre-syncope. In the remaining 50 patients no diagnosis could be made because either no events occurred, the patients were lost to follow-up, had adverse events, or died prior to diagnosis. In 72 of the 83 patients with syncope during follow-up (87%), loop recording definitively determined whether an arrhythmia was the cause of symptoms or not. Diagnosis included bradycardia in 21 patients, pacemaker dysfunction in one patient, and tachycardia in 10 patients. One patient experienced multiple rhythm disturbances. Syncope was non-arrhythmic in 40 patients. The remaining 11 patients failed to press the activator. Therapy was instituted in all patients, in whom an arrhythmic cause was found. Severe anticipated device related complications occurred in three patients. CONCLUSION: An implantable loop recorder is useful for establishing a diagnosis when symptoms are recurrent but too infrequent for conventional monitoring techniques.

Equipment Design↗

PubMedDate not supplied

Active-specific immunotherapy of pancreatic carcinoma: usefulness of human pancreatic carcinomas in preparing autologous tumor vaccines.

Using a mouse model we investigate whether pancreatic carcinoma cells can serve as a basic material for the preparation of tumour vaccines. Human pancreatic carcinomas grown in nude mice were dissociated and stimulated with interferon-gamma and tocopherol acetate. Due to the very homogenous tumour material the yield of vital tumour cells even from small specimens was high enough to produce at least three vaccine doses each. Flow cytometric analyses of stimulated cells showed a significant increase in MHC I presenting cells compared to nonstimulated cells. These preliminary data suggest that beneath the successful application of tumor vaccines to renal carcinoma, melanoma, colon carcinoma and different gynaecological carcinomas pancreatic carcinoma could be a further candidate for this kind of therapy.

Animals↗