Extensive ablation during PVAI does not cause deterioration in LA function, and may cause long-term improvement, especially in patients with higher AF burden.

Adjuvant anterior LA ablation does not appear to impact procedural outcome in patients with paroxysmal AF but may offer benefit to patients with persistent/permanent AF.

Background The cannabinoid (CB) system is a rational novel target for treating opioid dependence, a significant public health problem around the world. This proof-of-concept study examined the potential efficacy of a CB1 receptor partial agonist, dronabinol, in relieving signs and symptoms of opioid withdrawal. Methods Twelve opioid dependent adults participated in this 5-week, inpatient, double-blind, randomized, placebo-controlled study. Volunteers were maintained on double-blind oxycodone (30mg oral, four times/day) and participated in a training session followed by 7 experimental sessions, each testing a single oral test dose (placebo, oxycodone 30 and 60mg, dronabinol 5, 10, 20, and 30mg [decreased from 40mg]). Placebo was substituted for oxycodone maintenance doses for 21 hours before each session in order to produce measurable opioid withdrawal. Outcomes included observer- and participant-ratings of opioid agonist, opioid withdrawal and psychomotor/cognitive performance. Results Oxycodone produced prototypic opioid agonist effects (i.e., suppressing withdrawal and increasing subjective effects indicative of abuse liability). Dronabinol 5 and 10mg produced effects most similar to placebo, while the 20 and 30mg doses produced modest signals of withdrawal suppression that were accompanied by dose-related increases in high, sedation, bad effects, feelings of heart racing, and tachycardia. Dronabinol was not liked more than placebo, showed some impairment in cognitive performance, and was identified as marijuana with increasing dose. Conclusion CB1 receptor activation is a reasonable strategy to pursue for the treatment of opioid withdrawal; however, dronabinol is not a likely candidate given its modest withdrawal suppression effects of limited duration and previously reported tachycardia during opioid withdrawal.

Background-Multiple morphologies, hemodynamic instability, or noninducibility may limit ventricular tachycardia (VT) ablation in patients with arrhythmogenic right ventricular dysplasia (ARVD). Substrate-based mapping and ablation may overcome these limitations. We report the results and success of substrate-based VT ablation in ARVD. Methods and Results-Twenty-two patients with ARVD were studied. Traditional mapping for VT was limited because of multiple/changing VT morphologies (nϭ14), nonsustained VT (nϭ10), or hemodynamic intolerance (nϭ5). Sinus rhythm CARTO mapping was performed to define areas of "scar" (Ͻ0.5 mV) and "abnormal" myocardium (0.5 to 1.5 mV). Ablation was performed in "abnormal" regions, targeting sites with good pace maps compared with the induced VT(s). Linear lesions were created in these areas to (1) connect the scar/abnormal region to a valve continuity or other scar or (2) encircle the scar/abnormal region. Eighteen patients had implanted cardioverter defibrillators, 15 had implanted cardioverter defibrillator therapies, and 7 had sustained VT (6 with syncope). VTs (3Ϯ2 per patient) were induced (cycle length, 339Ϯ94 ms), and scar was identified in all patients. Scar areas were related to the tricuspid annulus, proximal right ventricular outflow tract, and anterior/inferior-apical walls. Lesions connected abnormal regions to the annulus (nϭ12) or other scars (nϭ4) and/or encircled abnormal regions (nϭ13). Per patient, a mean of 38Ϯ22 radiofrequency lesions was applied. Short-term success was achieved in 18 patients (82%). VT recurred in 23%, 27%, and 47% of patients after 1, 2, and 3 years' follow-up, respectively. Conclusions-Substrate-based ablation of VT in ARVD can achieve a good short-term success rate. However, recurrences become increasingly common during long-term follow-up. (Circulation. 2005;111:3209-3216.)

In this registry of 1,221 patients, we did not observe LA thrombus in PAF patients with normal EF who present for PVAI. Prescreening CT alone is likely to be sufficient in paroxysmal AF patients with normal EF, and the use of TEE may not be needed.