Effects on Cardiac Performance of Atrioventricular Node Catheter Ablation Using Radiofrequency Current for Drug-Refractory Atrial Arrhythmias

Patients with atrial fibrillation or atrial flutter (AF) are candidates for radiofrequency (RF) catheter ablation of the atrioventricular (AV) node with the aim being to control heart rate. As patients wilh AF can have markedly impaired ventricular function, information concerning the hemodynamic effects of AV node ablation using RF current would be valuable. Fourteen consecutive patients (mean age 65 ± 3 years) with drug-resistant AF underwent AV node catheter ablation with RF current and had permanent pacemaker implantation. The mean left ventricular ejection fraction (FFJ by two-dimensional echoeardiography immediately before ablation was 42 ± 3% (range 14%–54%) and their mean exercise time was 4.4 ± 0.4 minutes. Complete AV block was achieved in all 14 patients with 6 ± 2 RF applications (range 1–18). There was no evidence of any acute cardiodepressant effect associated with delivery of RF current, and EF 3 days after ablation was 44 ± 4%. By 6 weeks after ablation, the left ventricular EF was significantly improved compared to baseline (47 ± 4% postablation vs 42 ± 3% preahlation; P < 0.05), and this modest increase in EF was accompanied by an improvement in exercise time (5.4 ± 0.4 min). In conclusion, delivery of RF current for AV node catheter ablation in patients with AF and reduced ventricular function is not associated with any acute cardiodepressant effect. On the contrary, improved control of rapid heart rate following successful AV node ablation is associated with a modest and progressive improvement in cardiac performance.     

Using the Surface ECG to Identify Right Ventricular Pacing Lead Position: A Cautionary Tale

Chronic right ventricular (RV) apical pacing may lead to the development of heart failure in some patients. Although pacing of the RV septum has been proposed as an alternative, positioning a lead in the true septum has proven challenging. In addition to fluoroscopy at implant, it has been suggested that 12‐lead surface electrocardiogram (ECG) can be used to determine septal lead position; however, studies show this may be inaccurate. We present a case where a change in the ECG QRS axis late after pacemaker insertion with an active fixation lead highlights the difficulties of ECG localization of pacing leads.     

Halcinonide in the treatment of corticosteroid responsive dermatoses

Eighty-eight patients with bilateral lesions of atopic dermatitis, eczematous dermatitis, neurodcrmatitis or psoriasis were treated, without occlusion, with halcinonide and with betamethasone 17-valerate creams (0.1%) and evaluated in a double-blind, paired comparison study. In the forty-three psoriatic patients, halcinonidc was superior in twenty-three, betamethasone 17-valerate was superior in four, both drugs were equally effective in fourteen, and neither drug was effective in two. In the evaluation of all eighty-eight patients, halcinonide was superior in forty-two, betamethasone 17-valerate was superior in eight, both drugs were equally effective in twenty-nine, and neither drug was effective in nine. The overall superiority of halcinonide to betamethasone 17-valerate was highly significant (P <0.001). Halcinonide exhibited its superiority each week of the 3-week study. There were no side effects with either drug. The substitution of a chlorine atom for a hydroxyl group in the 21-position of the triamcinolone acctonide molecule, and the use of a specifically formulated cream vehicle containing propylene glycol and water, have yielded an extremely active topical anti-inflammatory drug.