Posterior Wall Isolation for Atrial Fibrillation: Effects on Echocardiographic Parameters of cardiac function.

BACKGROUND: Posterior wall isolation (PWI) in addition to circumferential pulmonary vein isolation (CPVA) requires more ablation of left atrial tissue. We compared the effect of PWI versus non-PWI methods (CPVA + linear lesions) on echocardiographic parameters of left atrial and left ventricular function. METHODS: We selected patients who had pre and post ablation echocardiogram at our institution. Parameters assessed were: Left ventricular outflow tract velocity time integral (VTI), left ventricular ejection fraction (LVEF), atrial Doppler velocity across mitral valve (A), E/E', and deceleration time. RESULTS: Of the 72 patients studied, 32.5% had PWA in addition to CPVA. The mean duration between echocardiograms was 650 + 542 days. PWA group had an average postoperative VTI 0.21 + 0.05 vs 0.21 + 0.05 in the non-PWA (p=0.61) group. Average improvement compared to pre ablation parameters: VTI was 0.03 + 0.06 vs 0.008 + 0.05 (p=0.17), postoperative A was 0.49 + 0.19 vs 0.57 + 0.19 (p=0.16), postoperative LVEF was 57.5 + 9.9% vs 57.8 + 10.8 % (p=0.89), with average change in LVEF 1.5 ± 7.8 vs 0.86 ± 9.7 (p=0.78) in PWA and non-PWA groups respectively. There was no significant difference in change in deceleration time or E/E' when comparing the two groups. CONCLUSIONS: PWA did not adversely affect echocardiographic parameters of left atrial function or left ventricular systolic or diastolic function when compared to other types of ablation.

Comparison of Cryoballoon and Hybrid surgical Posterior Wall Isolation for Persistent Atrial Fibrillation to conventional ablation.

BACKGROUND: Optimalablation strategy for persistent atrial fibrillation (AF) is unclear;PWI of the left atrium may improve outcome.Our aim was to compare outcomes of posterior wall isolation (PWI) ablation for persistent AF achieved by cryoballoon ablation (CRYO) or hybrid surgical ablation (HABL) to matched patients undergoing conventional radiofrequency ablation (CRA). METHODS: In our single center retrospective study,patients underwent HABL and CRYO withcircumferential pulmonary vein ablation (CPVA),roof and floor lines to complete PW box lesion. CRA consisted of CPVA, roof line and lateral mitral isthmus line (MVI). RESULTS: Of 61 patients (mean duration of AF 1.3 ± 0.4 yrs)who underwent ablation, after follow-up of 366 ± 62 days, AF recurrence was 10.5% and 48% (p=0.001) and the need for repeat ablation 5% vs 30% (p=0.007) in PWI and CRA groups respectively, without a significant difference in incidence of AT/FL 18 vs 26 % or cardioversion 5.2 vs 7.1 %. Total procedure time and fluoroscopic time were 242 ±70 min vs 279 ±53 min (p=0.08) and 20±9 min vs 12 ± 4 min (p=0.003) for PWI and CRA respectively. CRYO had less AF recurrence and complications than HABL. Mean length of stayfor CRYO patients was 41 hrs compared to 145 hrs in HABL group, who underwent two procedures. CONCLUSION: PWI in persistent AF patients decreases recurrence of AF and need for repeat procedure compared to CRA; PWI by CRYO is superior to HABL due to less LOS and complications.

CAABL-AF (California Study of Ablation for Atrial Fibrillation): Mortality and Stroke, 2005 to 2013.

BACKGROUND: Ablation for atrial fibrillation (AF) is superior to medical therapy for rhythm control. We compared stroke and mortality among patients undergoing ablation for AF to matched controls in a large multiethnic population. METHODS: Using discharge and surgical records from California nonfederal hospitals, we identified patients who had ablation and principal diagnosis of AF with at least 1 prior hospitalization for AF. We excluded cases with valve disease, open maze, other arrhythmias, or implantable devices. Matched controls were selected based on years of AF diagnosis, age, sex, and being alive the same number of days from the initial AF encounter to the ablation date. Clinical outcomes, including mortality, ischemic stroke, or hemorrhagic stroke, were assessed using a weighted proportional hazard model, adjusting for demographics, prior admissions with AF before the ablation, calendar year, and presence of chronic comorbidities. RESULTS: There were 4169 ablation cases and 4169 weighted-matched controls; 39% percent of the ablation group was >65 years, 72% men, 84% white; mean follow-up was up to 3.6±0.9 years. In adjusted models, ablation was associated with significantly lower mortality (per patient-years) 0.9% versus 1.9%, hazard ratio=0.59 (P<0.0001; confidence interval: 0.45-0.77); ischemic stroke (>30 days post-ablation ≤5 years), 0.37% versus 0.59%, hazard ratio=0.68 (P=0.04; confidence interval: 0.47-0.97); hemorrhagic stroke 0.11% versus 0.35%, hazard ratio=0.36 (P=0.001; confidence interval: 0.20-0.64) compared with controls. CONCLUSIONS: In this large population-based study of hospitalized patients with nonvalvular AF, ablation was associated with lower mortality, ischemic stroke, and hemorrhagic stroke compared with controls.

Brief exposure to secondhand smoke reversibly impairs endothelial vasodilatory function.

INTRODUCTION: We sought to determine the effects of brief exposures to low concentrations of tobacco secondhand smoke (SHS) on arterial flow-mediated dilation (FMD, a nitric oxide-dependent measure of vascular endothelial function), in a controlled animal model never before exposed to smoke. In humans, SHS exposure for 30 min impairs FMD. It is important to gain a better understanding of the acute effects of exposure to SHS at low concentrations and for brief periods of time. METHODS: We measured changes in FMD in rats exposed to a range of real-world levels of SHS for durations of 30 min, 10 min, 1 min, and 4 breaths (roughly 15 s). RESULTS: We observed a dose-response relationship between SHS particle concentration over 30 min and post-exposure impairment of FMD, which was linear through the range typically encountered in smoky restaurants and then saturated at higher concentrations. One min of exposure to SHS at moderate concentrations was sufficient to impair FMD. CONCLUSIONS: Brief SHS exposure at real-world levels reversibly impairs FMD. Even 1 min of SHS exposure can cause reduction of endothelial function.

Evidence for an additional locus for split hand/foot malformation in chromosome region 8q21.11-q22.3.

We identified a family where five members had nonsyndromic ectrodactyly. There were three known instances of nonpenetrance. Although four individuals had unilateral cleft hand, one individual had more severe, bilateral and asymmetric absence of the digits. None had foot abnormalities. After exclusion of linkage of SHFM in this family to five known loci, a genome wide scan was performed with DNA from 5 affected and 15 unaffected members of this family. Suggestive evidence for linkage of ectrodactyly to 8q was obtained on the basis of a maximum LOD score of 2.54 at theta (max) = 0 with GAAT1A4. Critical recombinants place the ectrodactyly gene in this family in a 16 cM (21 Mb) interval between D8S1143 and D8S556. Mutational analysis of two candidate genes (FZD6, GDF6) did not identify any mutations in affected members of this family. Our data indicate further genetic heterogeneity for ectrodactyly and suggest the presence of an additional SHFM locus in chromosome region 8q21.11-q22.3.