Background— There has been growing concern that linear ablation is associated with an increased risk of iatrogenic arrhythmias in patients undergoing ablation for atrial fibrillation (AF). Therefore, we compared circumferential pulmonary vein ablation plus left atrial linear ablation (CPVA+LALA) with segmental pulmonary vein isolation (PVI)in patients with paroxysmal AF. Methods and Results— Sixty-six consecutive patients with paroxysmal AF were prospectively randomly assigned to receive PVI versus CPVA+LALA (consisting of encircling lesions around the pulmonary veins), a roof line, and a mitral isthmus line with documentation of bidirectional mitral isthmus block. All patients were seen at 1, 3, 6, and every 12 months after ablation, with 14-day continuous ECG monitoring every 6 months. At 16.4±6.3 months after 1 ablation procedure, 19 patients (58%) remained free of atrial arrhythmias after PVI versus 17 patients (51%) after CPVA+LALA ( P =0.62). After PVI, 14 patients had recurrent paroxysmal AF, whereas after CPVA+LALA, 8 patients had recurrent AF, 6 had atypical left atrial flutter (LAFL), and 2 had both AF and LAFL ( P =0.32 between PVI versus CPVA+LALA for AF but P =0.002 for LAFL). Twenty-eight patients (85%) remained arrhythmia-free after 1.3±0.5 PVI procedures versus 28 patients (85%) after 1.4±0.6 CPVA+LALA procedures ( P =NS). Fluoroscopy time was longer after CPVA+LALA versus PVI (91 versus 73 minutes, P =0.04). Conclusions— As an initial ablation approach in patients with paroxysmal AF, more LAFL occurred after CPVA+LALA and fluoroscopy times were longer compared with segmental PVI.

Objective Previous work studying vegetarians has often found that they have lower blood pressure (BP). Reasons may include their lower BMI and higher intake levels of fruit and vegetables. Here we seek to extend this evidence in a geographically diverse population containing vegans, lacto-ovo vegetarians and omnivores. Design Data are analysed from a calibration sub-study of the Adventist Health Study-2 (AHS-2) cohort who attended clinics and provided validated FFQ. Criteria were established for vegan, lacto-ovo vegetarian, partial vegetarian and omnivorous dietary patterns. Setting Clinics were conducted at churches across the USA and Canada. Dietary data were gathered by mailed questionnaire. Subjects Five hundred white subjects representing the AHS-2 cohort. Results Covariate-adjusted regression analyses demonstrated that the vegan vegetarians had lower systolic and diastolic BP (mmHg) than omnivorous Adventists (β =−6·8, P<0·05 and β = −6·9, P<0·001). Findings for lacto-ovo vegetarians (β = −9·1, P<0·001 and β = −5·8, P<0·001) were similar. The vegetarians (mainly the vegans) were also less likely to be using antihypertensive medications. Defining hypertension as systolic BP > 139 mmHg or diastolic BP > 89 mmHg or use of antihypertensive medications, the odds ratio of hypertension compared with omnivores was 0·37 (95 % CI 0·19, 0·74), 0·57 (95 % CI 0·36, 0·92) and 0·92 (95 % CI 0·50, 1·70), respectively, for vegans, lacto-ovo vegetarians and partial vegetarians. Effects were reduced after adjustment for BMI. Conclusions We conclude from this relatively large study that vegetarians, especially vegans, with otherwise diverse characteristics but stable diets, do have lower systolic and diastolic BP and less hypertension than omnivores. This is only partly due to their lower body mass.

Objective To compare cardiovascular risk factors between vegetarians and non-vegetarians in black individuals living in the USA. Design A cross-sectional analysis of a sub-set of 592 black women and men enrolled in the Adventist Health Study-2 (AHS-2) cohort of Seventh-day Adventists. Setting Members of the AHS-2 cohort, who lived in all states of the USA and provinces of Canada. Subjects Black/African-American members of two sub-studies of AHS-2 where blood and physiological measurements were obtained. Results Of these women and men, 25% were either vegan or lacto-ovo-vegetarians (labelled ‘vegetarian/vegans’), 13 % were pesco-vegetarian and 62% were non-vegetarian. Compared with non-vegetarians, the vegetarian/vegans had odds ratios for hypertension, diabetes, high blood total cholesterol and high blood LDL-cholesterol of 0·56 (95% CI 0·36, 0·87), 0·48 (95% CI 0·24, 0·98), 0·42 (95% CI 0·27, 0·65) and 0·54 (95% CI 0·33, 0·89), respectively, when adjusted for age, gender, education, physical activity and sub-study. Corresponding odds ratios for obesity in vegetarian/vegans and pesco-vegetarians, compared with non-vegetarians, were 0·43 (95% CI 0·28, 0·67) and 0·47 (95% CI 0·27, 0·81), respectively; and for abdominal obesity 0·54 (95% CI 0·36, 0·82) and 0·50 (95% CI 0·29, 0·84), respectively. Results for pesco-vegetarians did not differ significantly from those of non-vegetarians for other variables. Further adjustment for BMI suggested that BMI acts as an intermediary variable between diet and both hypertension and diabetes. Conclusions As with non-blacks, these results suggest that there are sizeable advantages to a vegetarian diet in black individuals also, although a cross-sectional analysis cannot conclusively establish cause.

Background-Left atrial linear ablation for atrial fibrillation (AF) may be proarrhythmic, leading to left atrial macro-reentrant tachycardia (LAT). Whether due to failure to achieve block initially or to recovery of conduction after ablation is unknown. This study was designed to evaluate the frequency of recovery of mitral isthmus (MI) conduction compared with cavo-tricuspid isthmus (CTI) conduction, and the relationship between recovery of MI conduction and postablation LAT. Methods and Results-Of 163 patients with AF who underwent circumferential pulmonary vein ablation plus left atrial linear ablation, in whom MI and CTI ablation produced bidirectional conduction block, 52 underwent repeat ablation for recurrent atrial arrhythmias (AF or LAT). Of these 52 patients, coronary sinus ablation was required in 48 to achieve bidirectional MI block at the index ablation. During repeat ablation, MI and CTI conduction was assessed in sinus rhythm. At repeat ablation, MI conduction had recovered in 38 of 52 patients, as compared with CTI conduction which recovered in only 12 of 52 patients (Pϭ0.001). At repeat ablation, the recurrent clinical arrhythmia in 12 patients was MI-dependent LAT. Recovery of MI conduction was associated with development of MI-dependent LAT (Pϭ0.01). Conclusions-Despite using bidirectional conduction block as a procedural end point, recovery of MI conduction is common and may lead to LAT after left atrial linear ablation for AF. The reason for greater recovery of MI versus CTI conduction is unknown but could be due to differences in isthmus anatomy or lower power used for ablation in the left versus right atrium. (Circ Arrhythm Electrophysiol. 2011;4:832-837.)

Introduction Most trials evaluating the efficacy of atrial fibrillation ablation report follow-up periods of 1–2 years. Long term results (> 5 years) following segmental pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation (PAF) are largely unreported. Objective To evaluate the long-term efficacy of segmental PVI for the treatment of symptomatic, medically refractory, PAF. Methods Patients with paroxysmal atrial fibrillation who underwent pulmonary vein isolation at the University of California, San Diego Medical Center were evaluated retrospectively to determine the outcome of the index procedure. Of one hundred and eighteen segmental pulmonary vein isolation procedures preformed at UCSD Medical Center between January 1, 2002 and August 31, 2003, seventy-one patients who had long-term follow-up data were included. The five year outcomes were determined by last clinic encounter and telephone encounter at or after five years from the index procedure. Patients had routine clinic visits with EKGs and underwent cardiac monitoring for any complaints of symptoms suggestive of recurrent arrhythmia. Results Seventy-one patients (60±10 years, 56 male) were followed for > 5 years. After one procedure, with 12 months of follow up, sixty-one (86%) of patients were free from symptomatic atrial fibrillation (AF). After 24 months, fifty-six (79%) of patients remained free of AF. At the end of a follow up period of 63±5 months, only forty patients (56%) remained free from symptomatic atrial fibrillation after one procedure. In sixteen patients (22.5%), atrial fibrillation recurred after the second year post-ablation, with four patients recurring during the third year, four patients during the fourth year, and eight patients having their first recurrence of atrial fibrillation greater than 48 months after their index ablation procedure. Thirty-one patients underwent more than one ablation procedure (average 1.9±0.9 procedures per patient). After multiple procedures, sixty patients (84%) were arrhythmia free off medication at 63±5 months after their initial procedure. In patients who underwent more than one ablation procedure, the mean duration of follow up after the last ablation procedure was 7.5±2.1 months. Conclusions Overall five-year outcomes after segmental PVI for PAF are consistent with previously reported shorter term follow-up (≤ 2 years); however, late recurrences (>2 years) after a successful initial ablation procedure are not infrequent, and repeat ablation procedures are often required to maintain freedom from symptomatic arrhythmias. Continued long-term follow-up of patients with PAF after initially successful ablation may be warranted, especially in those patients in whom anticoagulation is discontinued.

AT occurring after CPVA plus LALA is often due to incomplete MI ablation, but may also occur at the LA roof, and ridge between the LA appendage and left PVs. Failure to achieve MI block increases the risk of developing AT. Resumption of MI conduction may also be a mechanism for AT recurrence. (PACE 2010; 460-468).

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Subclinical pericardial effusions are common in patients with untreated hypothyroidism and usually resolve with thyroid replacement therapy, but cardiac tamponade is a rare presentation of prolonged untreated hypothyroidism. We report the first case of cardiac tamponade due to hypothyroidism produced by administration of amiodarone. KEYWORDS: Cardiac tamponade, hypothyroidism, amiodarone therapyAccumulation of proteinaceous fluid in vital body cavities of patients with hypothyroidism is widely documented. The most common sites for fluid accumulation are the pericardial, pleural, and peritoneal cavities. 1 The reported incidence of pericardial effusion in hypothyroid patients is 3% in an early mild stages to 80% when myxedema is present, 2,3 but cardiac tamponade is very rare and happens in prolonged untreated hypothyroisim. 4 Hypothyroidism is common in patients receiving amiodarone, but cardiac tamponade secondary to this has not been reported to our knowledge. [5][6][7] We report the first case of cardiac tamponade caused by hypothyroidism produced by administration of amiodarone. CASE REPORTA 69-year-old Caucasian man with medical history of hypertensive cardiomyopathy, colon cancer, and atrial fibrillation presented with progressive dyspnea on exertion and fatigue over a period of weeks. He was on longterm amiodarone therapy; 200 mg twice a day for several years. Physical examination revealed blood pressure of 95/54 mm Hg and heart rate of 67 beats per minute with distended jugular veins and distant heart sounds.The chest X-ray revealed massive cardiomegaly (Fig. 1A). Chest computed tomography scan performed to evaluate the metastatic cancer revealed a large pericardial effusion (Fig. 1B). Echocardiography confirmed the diagnosis of massive pericardial effusion with tamponade physiology consisting of markedly dilated inferior vena cava and respirophasic variations in transvalvular flows (Fig. 1C). The clinical suspicion of hypothyroidism was supported by an elevated thyroid stimulating hormone level of 77.7 mIU/mL (normal 0.4 to 4.0 mIU/mL) and decreased plasma-free thyroxine level of 0.62 ng/dL (normal 0.8 to 2.0 ng/dL).The patient underwent emergent echocardiographically guided pericardiocentesis with drainage of 1.4 L of straw-colored fluid. The patient had marked improvement in symptoms and blood pressure with pericardiocentesis. The protein content of the fluid was 2.5 g/dL and cytology was negative for malignant cells. Follow-up chest X-ray showed a dramatic reduction in