Time matters: adenosine testing immediately after pulmonary vein isolation does not substitute a waiting period.

AIMS: Adenosine testing can reveal dormant pulmonary vein (PV) conduction after PV antrum isolation (PVAI). However, the optimal timing for adenosine administration is unknown. We hypothesized that adenosine testing immediately after PVAI reliably reveals PV reconnection and thereby eliminates the need for an observation period. METHODS AND RESULTS: Fifty patients underwent PVAI. Immediately after isolation of a PV pair, adenosine was administered. Both PV pairs were separately tested. If adenosine restored PV conduction, PVs were re-isolated. During a ≥30 min observation period after immediate adenosine-guided isolation, spontaneous reconnection was assessed and reconnected PVs were re-isolated. After the observation period, adenosine testing was repeated. Immediate adenosine testing revealed dormant conduction in 10.4% of the left PVs and 16.3% of the right PVs. All PVs were successfully re-isolated. During a mean observation period of 36 ± 10 min, spontaneous reconnection occurred in 8.2% of the left and 16.3% of the right PVs. None of these PVs had shown reconnection during immediate testing. Late adenosine testing revealed dormant conduction in 12.5% of the left and 16.3% of the right PVs. In patients without reconnection during immediate adenosine testing, 14.6% of the left PVs and 30.6% of the right PVs showed either spontaneous reconnection or restored PV conduction during late adenosine testing. CONCLUSION: Adenosine testing immediately after PVAI does not reliably exclude later spontaneous or adenosine-induced PV reconnection. Adenosine testing should be performed after an appropriate observation period to reduce risk of PV reconnection.

Five-year efficacy of pulmonary vein antrum isolation as a primary ablation strategy for atrial fibrillation: a single-centre cohort study.

AIMS: Pulmonary vein antrum isolation (PVAI) is the cornerstone of atrial fibrillation (AF) ablation. There is an ongoing discussion on whether and when to add substrate modification to PVAI. This study evaluates (1) long-term efficacy of PVAI as a primary ablation strategy in all patients independently from AF type and (2) predictors of arrhythmia recurrence. METHODS AND RESULTS: A total of 509 consecutive patients (mean age 57 years, 38.9% non-paroxysmal AF) with AF underwent PVAI. In redo procedures, ablation was restricted to re-pulmonary vein (PV) isolation in case of PV reconnection. If the PVs were found to be isolated, substrate modification was performed. In total, 774 procedures were performed. Mean follow-up duration after the first and last ablation was, respectively, 66 ± 23 and 55 ± 25 months. A single PVAI was sufficient in restoring and maintaining long-term sinus rhythm in 41.3% (n = 210) of patients. Multiple procedures (mean 1.5) with re-PV isolation increased long-term success to 58.3% (n = 297). Additional substrate modification (n = 70) increased success to 62.5% (n = 318). After the last ablation, 87.5% of patients experienced success or significant clinical improvement on or off antiarrhythmic drugs. The incidence of left-sided atrial flutter or atrial tachycardia was 5% after PVAI and increased to 32% after additional substrate modification. Independent predictors for arrhythmia recurrence after the last ablation were non-paroxysmal AF, female sex, body mass index, hypertension, and AF duration. CONCLUSION: Five-year freedom of atrial tachyarrhythmia could be achieved by PVAI as primary ablation strategy in 58.3% of patients. Additional substrate modification only moderately increased overall success.

Double-contrast, single-phase computed tomography angiography for ruling out left atrial appendage thrombus prior to atrial fibrillation ablation.

Prior to atrial fibrillation (AF) ablation, computed tomography angiography (CTA) is increasingly used for left atrial appendage (LAA) thrombus detection. LAA filling defects on CTA may represent thrombus or incomplete contrast mixing with blood. A pre-bolus of contrast material with delay before the CTA contrast bolus can help distinguish between thrombus and incomplete contrast mixing. We present results from a double-contrast, single-phase CTA protocol used in our daily clinical practice. In patients who underwent AF ablation between 2011 and 2015, double-contrast, single-phase CTA was performed prior to ablation. Two contrast boluses (30 and 70 ml) with 25-s interbolus delay were administered followed by prospectively triggered cardiac CTA. Only patients with left atrial (LA) or LAA filling defects underwent transesophageal echocardiography (TEE) to rule out thrombus. Prior to ablation, 605 CTA-scans were performed (median radiation dose: 3.1 mSv). In 579 CTA-scans (95.7 %), the LA and LAA completely filled with contrast. In 26 CTA-scans (4.3 %) the LAA showed a filling defect whereby thrombus could not be excluded. In 2 of those 26 patients (7.7 % and 0.3 % of the total population), TEE verified LAA thrombus. Low-risk LAA filling defects on CTA (n = 7/26) with an inhomogeneous aspect, Houndsfield Unit values >100, and an indefinite border were all caused by incomplete contrast mixing. No thromboembolic complications occurred perioperatively or during 6 months follow-up. Prior to AF ablation, incidence of LAA filling defects on double-contrast, single-phase CTA is low. TEE remains warranted in all but low-risk filling defects to rule out thrombus.

Incidence of Pulmonary Vein Stenosis After Radiofrequency Catheter Ablation of Atrial Fibrillation.

OBJECTIVES: This study aimed to determine incidence of pulmonary vein stenosis (PVS) and evaluate PVS-related symptoms. BACKGROUND: The real-life incidence of PVS after radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF) is unknown. METHODS: All patients who underwent RFCA of AF from 2005 to 2016 with routine pre- and post-ablation screening by magnetic resonance imaging or computed tomography were included. Primary ablation strategy was PV antrum isolation alone in all patients. PVS, defined as a significant reduction in the superoinferior or anteroposterior PV diameter, was classified as mild (30% to 50%), moderate (50% to 70%), or severe (>70%). RESULTS: Sufficient quality imaging of the PV anatomy before ablation and during follow-up (mean 6 ± 4 months) was performed in 976 patients (76.4% men, 59.1% paroxysmal AF). Of these patients, 306 (31.4%) showed mild stenosis, 42 (4.3%) revealed moderate stenosis, and 7 (0.7%) had a severe stenosis in at least 1 PV. Incidence of PVS fluctuated over the past decade. All severe PVS cases were likely caused by ablations being performed inside the PVs. Only 1 (0.1%) patient reported PVS-related symptoms of severe dyspnea during follow-up. Computed tomography revealed a subtotal occlusion of the left inferior PV and a severe stenosis of the left superior PV, requiring stenting. CONCLUSIONS: Although mild PVS was frequently observed after RFCA in this large cohort, incidence of severe PVS was <1% and incidence of symptomatic PVS necessitating intervention was negligible. Based on these findings, it seems appropriate to only screen for PVS in patients with suggestive symptoms.