is not a standard primary outcome in ablation trials, even though symptoms drive the indication. OBJECTIVE To assess quality of life with catheter ablation vs antiarrhythmic medication at 12 months in patients with atrial fibrillation. DESIGN, SETTING, AND PARTICIPANTS Randomized clinical trial at 4 university hospitals in Sweden and 1 in Finland of 155 patients aged 30-70 years with more than 6 months of atrial fibrillation and treatment failure with 1 antiarrhythmic drug or β-blocker, with 4-year follow-up. Study dates were July 2008-September 2017. Major exclusions were ejection fraction <35%, left atrial diameter >60 mm, ventricular pacing dependency, and previous ablation. INTERVENTIONS Pulmonary vein isolation ablation (n = 79) or previously untested antiarrhythmic drugs (n = 76). MAIN OUTCOMES AND MEASURES Primary outcome was the General Health subscale score (Medical Outcomes Study 36-Item Short-Form Health Survey) at baseline and 12 months, assessed unblinded (range, 0 [worst] to 100 [best]). There were 26 secondary outcomes, including atrial fibrillation burden (% of time) from baseline to 12 months, measured by implantable cardiac monitors. The first 3 months were excluded from rhythm analysis. RESULTS Among 155 randomized patients (mean age, 56.1 years; 22.6% women), 97% completed the trial. Of 79 patients randomized to receive ablation, 75 underwent ablation, including 2 who crossed over to medication and 14 who underwent repeated ablation procedures. Of 76 patients randomized to receive antiarrhythmic medication, 74 received it, including 8 who crossed over to ablation and 43 for whom the first drug used failed. General Health score increased from 61.8 to 73.9 points in the ablation group vs 62.7 to 65.4 points in the medication group (between-group difference, 8.9 points; 95% CI, 3.1-14.7; P = .003). Of 26 secondary end points, 5 were analyzed; 2 were null and 2 were statistically significant, including decrease in atrial fibrillation burden (from 24.9% to 5.5% in the ablation group vs 23.3% to 11.5% in the medication group; difference-6.8% [95% CI,-12.9% to-0.7%]; P = .03). Of the Health Survey subscales, 5 of 7 improved significantly. Most common adverse events were urosepsis (5.1%) in the ablation group and atrial tachycardia (3.9%) in the medication group. CONCLUSIONS AND RELEVANCE Among patients with symptomatic atrial fibrillation despite use of antiarrhythmic medication, the improvement in quality of life at 12 months was greater for those treated with catheter ablation compared with antiarrhythmic medication. Although the study was limited by absence of blinding, catheter ablation may offer an advantage for quality of life.

The effects of sympathetic nerve stimulation on vasoconstrictor responses and overflow of norepinephrine (NE) and neuropeptide Y-like immunoreactivity (NPY-LI) were studied in the dog gracilis muscle and pig spleen in vivo. A continuous regular impulse activity was compared with irregular human sympathetic and regular bursting patterns. During control conditions, stimulation with the irregular activity induced larger peak vasoconstriction than the regular activity at 0.59 Hz, but not at higher frequencies in the muscle, at 0.59 and 2.0 Hz in the spleen. The nerve stimulation-evoked overflow of NE and NPY-LI from the muscle were not influenced by the pattern of stimulation. The overflow of NPY-LI, but not that of NE, from the spleen was enhanced by the irregular activity at 0.59 and 2.0 Hz, and both NPY-LI and NE overflows were enhanced by regular burst activity at 2.0 Hz. After blockade of alpha- and beta-adrenoceptors by phenoxybenzamine and propranolol, respectively, which enhanced nerve stimulation-evoked overflow of both NE and NPY-LI, the NE overflow from the muscle evoked by the irregular activity was slightly larger at 0.59 Hz but smaller at higher frequencies compared with that evoked by regular activity, whereas the detectable overflow of NPY-LI was not largely influenced by the stimulation pattern. In conclusion, both the vasoconstrictor response and the overflow of NPY-LI and NE seem to be influenced by the pattern and frequency of sympathetic nerve stimulation.

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In patients with paroxysmal AF undergoing either RF or CB PVI as the sole ablation strategy, the incidence of postprocedural AT was low and there was no significant difference between the 2 techniques.

The pharmacokinetics of clevidipine, a potent short-acting vascular-selective calcium antagonist, was investigated during steady state and the postinfusion period in patients with mild to moderate hypertension. Furthermore, the dose-effect and blood concentration-effect relations and the tolerability of the drug were studied. Twenty patients were randomized to clevidipine intravenously at target dose rates of 0.18, 0.91, 2.74, and 5.48 microg/kg/min, respectively, or placebo. Each patient received in random order three infusion rates of clevidipine or placebo during three separate study days. Dose-dependent reduction in blood pressure and a modest increase in heart rate were noted. The extremely high clearance value and the small volume of distribution resulted in short half-lives of clevidipine, 2.2 and 16.8 min, respectively. The blood concentration and dose rate producing half the maximal effect (i.e. EC50 and ED50) were approximately 25 nM and 1.5 microg/kg/min, respectively. There was a linear relation between blood concentration and dose rate in the range studied. Clevidipine was safe and generally well tolerated; one patient was excluded because of adverse events at 2.74 microg/kg/min. In conclusion, clevidipine is a high-clearance calcium antagonist that may become a valuable contribution to the drugs used in conditions in which precise and rapid control of blood pressure is needed.

Cryoablation in AVNRT is safe with a long-term efficacy of 88%; however, very late recurrences occur.

Cryoablation of AVNRT can be achieved with a high acute success rate and a reasonable recurrence rate at long-term follow-up. Complete abolition of slow pathway conduction seems to predict better late outcome.

Cryoablation of isthmus-dependent AFL is not inferior to RF but with significantly less procedure-related pain.