Radiofrequency Ablation of Concealed Left Free-Wall Accessory Pathways Without Coronary Sinus Catheterization:

Ablation of Concealed Accessory Pathways. Introduction: Feasibility of radiofrequency (RF) ablation using a two-catheter technique without coronary sinus catheterization was studied in 100 consecutive patients with a single concealed left free-wall accessory path-way.
Methods and Results: Tachycardia was induced by electrical stimulation in the right atrium/right ventricle, and the presence of a concealed left free-wall accessory pathway was suggested electrocardiographically (negative P wave in leads I and/or a VL during orthodromic tachycardia) or by earlier atrial activation in the pulmonary artery compared to the high right atrium. Mapping of the mitral annulus was performed during right ventricular pacing or orthodromic tachycardia, and RF energy was applied at the site with the earliest retrograde atrial activation. Ablation was considered effective if tachycardia could not be induced, and if VA dissociation or exclusive retrograde nodal conduction was observed. Ablation was initially successful in 98 of 100 patients. Mean number of radiofrequency pulses were 3.2 ± 2. Mean fluoroscopy time and total procedure time was 14 ± 9 and 107 ± 32 minutes, respectively. There were no complications related to the procedure. At a mean follow-up of 22 ± 13 months, two patients experienced tachycardia recurrence and required a second procedure, which was successful.
Conclusions: Our results suggest that RF catheter ablation of concealed left free-wall accessory pathways can be safely, effectively, and rapidly performed using a simplified two-catheter technique with no need for coronary sinus catheterization.     

Radiofrequency Ablation of Symptomatic but Benign Ventricular Arrhythmias

Two cases are presented where ablation of severely symptomatic ventricular arrhythmias not responding to medical therapy was accomplished with radiofrequency current application. After a routine programmed stimulation protocol, a quadripolar ablation catheter with a 4-mm tip was advanced percutaneously into the left ventricle in one case and into the right ventricle in the second case; and after precise pace mapping, the arrhythmogenic focus was successfully ablated using radiofrequency current. The postablation ambulatory recording revealed virtual eradication of ventricular ectopy in both cases. In conclusion, in severely symptomatic cases of "benign" ventricular arrhythmias, radiofrequency ablation offers an effective therapeutic alternative.     

Health impact of head and neck cancer

A multidimensional Head and Neck Quality of Life (HNQOL) instrument and a general health status measure were administered to 397 patients with head and neck cancer. Scores for the 4 domains of the HNQOL (communication, eating, pain, and emotional well-being) were calculated. Patient demographics, comorbidities, clinical characteristics, treatment data, disability status, and a global "overall bother" score were assessed. When compared with the US population aged 55 to 64 years, the group had significantly worse scores in the 8 health domains of the SF-36. Patients' overall bother scores from the head and neck cancer treatment correlated best with the HNQOL emotion domain (r = 0.71) and the HNQOL pain domain (r = 0.63), and least with the patients' perception of their response to treatment (r = 0.39). Pain, eating, emotion, physical component summary score, age, and an interaction term between eating and emotion were significant predictors for overall bother. Of the 217 patients who were working before the diagnosis of cancer, 74 (34. 1%) reported that they had become disabled. Patients who had more than 1 type of treatment were 5.9 times more likely to report themselves as disabled (odds ratio [OR] = 5.94, P < 0.01), even after adjusting for age, emotion score, and physical component summary score, which were other factors that predicted disability.     

Relevance of Atrial Fibrillation Classification in Clinical Practice

Atrial Fibrillation Classification. Use of different classifications for atrial fibrillation reflects the complexity of the arrhythmia and the difficulty in grouping its different aspects. Current classifications are based on clinical presentation, etiology, substrates, mechanisms, etc. From the clinical point of view, the most relevant probably should be one directed at classifying patients in terms of therapeutic options. In this article, a review of known classifications is given, together with an attempt at a new classification based on the possibility of offering a nonpharmacologic treatment to patients.     

Effects of quinidine on ventricular repolarization

The possibility that an asynchronous increase in the ventricularmonophasic action potential duration is the basis of the quinidine-inducedtorsade de pointes, has led us to study the electrophysiologicaleffects of increasing doses of intravenous quinidine. We measuredthe monophasic action potential duration and the ventriculareffective refractory period at several right ventricular myocardialsites in the anaesthetized dog.Our results showed that quinidineinduces a dose-dependent prolongation in ventricular effectiverefractory period and in ventricular monophasic action potentialduration. These increases were uniform throughout the rightventricle. No variations in repolarization or in refractorinesswere observed between the four ventricular sites studied.Theresults suggest that quinidine does not have a direct effecton dispersion of repolarization, and that mechanisms other thanits direct electrophysiological action are involved in the developmentof torsade de pointes.     

Short-term decrease of skin-test sensitivity after rush desensitization in Hymenoptera venom hypersensitivity

Thirty-seven patients with a history of systemic anaphylactic stings were desensitized by the rush method. Patients were evaluated by skin testing twice, before and 6 weeks after desensitization. An additional control group of 10 patients, not yet desensitized, were tested for skin test technique reproducibility at 6-week intervals. Results were compared with IgE and IgG antibody levels, and with platelet reactivity towards specific Hymenoptera venom. Before desensitization, the maximum skin-test sensitivity was observed at 10(-5) micrograms venom/ml in 56% of patients and decreased to 10(-1) micrograms venom/ml after desensitization (48.6% of patients). Decrease of cutaneous tests was observed in 28/37 patients (75%) (P less than 0.001) and was not associated with significant variations of specific IgE or IgG antibody levels, but was correlated with the decrease of platelet reactivity (P less than 0.05). Conversely, variations of skin-test sensitivity in the control group was not significant.     

Hemodynamic Deterioration Following Radiofrequency Ablation of the Atrioventricular Conduction System

Radiofrequeucy ablation of the atrioventricular conduction system (ACS) has become an estoblished theTapy for patients with drug refroctory atrial fibrillation. We observed eight patients with hemodynamic deterioration ofteT radiofrequency oblotion of the otTioventTicular conduction system. As we found hemodynamic deterioration related to worsening mitral regurgitation, we compared the clinical history, eiectrophysiologicai, ond echocardiographic dato from the patients with hemodynamic deteriorotion and worsening mitral regurgitation (group 1) to those without hemodynamic deterioration and stable mitral regurgitation after the procedure (group 2). Eight out of 108 patients (7.4%) undergoing ablation of the ACS deteriorated hemodynamically with acute pulmonary edema in three and congestive heart failure in five patients occurring at a mean of 3 and 8 weeks, respectively, after the procedure. Three of these patients were referred for mitral valve surgery. Two patients underwent ablation using a left-sided approach. A right-sided approach was used in five patients. In one patient, a left- and right-sided approach was used. Compared to group 2 patients, group 1 patients had significantly higher left ventricular end-diastolic diameters (64 ± 6 mm vs 56 ± 9 mm) at baseline despite similar fractional shortening (32%± Il% vs 34%± 13%), left ventricular end-systolic diameters (43 ± 9 mm vs36 ± 7 mm) and degree of mitral regurgitation (1.4 ± 1.1 vs 1.4 ±0.7) on echocardiographic analysis. Thus, hemodynamic deterioration together with progression of mitral regurgitation is a potential complication of ablation of the ACS (up to 7.4%). Patients with high left ventricular end-diastolic diameters ond moderate mitral regurgitation at baseline seem prone to this complication.