Optimal lesion size index to prevent conduction gap during pulmonary vein isolation.

INTRODUCTION: A novel real-time lesion size index (LSI) that incorporates contact force (CF), time, and power has been developed for safe and effective catheter ablation. The optimal LSI was evaluated to eliminate gap formation during pulmonary vein isolation (PVI). METHODS AND RESULTS: Consecutive patients were enrolled, who underwent their first PVI using a fiber-optic CF-sensing catheter for atrial fibrillation between December 2016 and October 2017. The CF parameters, force-time integral (FTI), and LSI for 3095 ablation points in 34 patients were evaluated. The FTI and LSI in the lesions with gaps or dormant conduction (gaps/DC) were significantly lower than those in the lesion without gaps/DC (FTI: 140.5 ± 54.5 and 232.4 ± 121.4 g s, P < 0.0001; LSI: 4.0 ± 0.6 and 4.7 ± 0.9, P < 0.0001, respectively). On receiver operating characteristic curve analysis, the optimal LSI threshold was 4.05 (sensitivity, 63.4%; specificity, 76.3%). The LSI of <5.25 predicted a gap or DC with a high sensitivity (sensitivity, 97.6%; specificity, 25.7%). In the posterior wall, which was 37% thinner than the nonposterior wall, a lower LSI of <3.95 showed a relatively high sensitivity (92.3%) and specificity (65.6%). CONCLUSIONS: The LSI can be used to predict gaps/DC during the PVI procedure. An LSI of 5.2 may be a suitable target for effective lesion formation. An LSI of 4.0 may be acceptable in the posterior wall, especially in areas adjacent to the esophagus.

Impact of left atrial size on isolation area in the acute phase of pulmonary vein isolation using 28 mm cryoballoon.

BACKGROUND: The impact of left atrial (LA) size on isolation area (ISA) using a 28-mm second-generation cryoballoon (CB) in the acute phase after pulmonary vein isolation (PVI) and the differences of CB from contact force-guided radiofrequency (RF) ablation have not been fully investigated. METHODS: We examined 85 consecutive patients (CB group, 35; RF group, 50) with drug-refractory paroxysmal atrial fibrillation who underwent their first PVI procedure at two institutions. We evaluated ISA after PVI using 3D-Merge computed tomography images (GE Healthcare, Little Chalfont, UK) and high-resolution electroanatomical mapping. RESULTS: Total ISA was significantly smaller in the CB group (20.6 ± 6.0 cm2 ) than in the RF group (29.0 ± 7.1 cm2 ; P < 0.0001). In the CB group, ISA of the left pulmonary vein (LPV), right pulmonary vein (RPV), and total ISA were not correlated with the left atrial surface area (LASA). The ratios of ISA to LASA (%ISA) of LPV and total ISA negatively correlated with LASA in the CB group (LPV: r = -0.4001, P = 0.0173; total ISA: r = -0.4733, P = 0.0041). In contrast, in the RF group, ISA of LPV, RPV, and total ISA positively correlated with LASA; (LPV: r = 0.5155, P = 0.001; RPV: r = 0.6398, P < 0.0001; total ISA: r = 0.7299, P < 0.0001). CONCLUSION: ISA created using CB was significantly smaller than that using RF and did not change regardless of LASA increment. Differences in ISA between the two groups became more prominent in the large atrium.

Pseudoaneurysm formation caused by the withdrawal of a Trevo ProVue stent at a tortuous cerebral vessel: a case report.

This is the first report on the mechanism of pseudoaneurysm formation after withdrawal of a stent retriever. A 79-year-old woman developed cardiogenic embolization of the distal middle cerebral artery (M2). The deployed stent retriever bent because of vessel tortuosity. After withdrawal of the stent with strong resistance, complete revascularization was achieved, but an extravasation was detected at the site. Eight hours after disappearance of the extravasation, re-bleeding occurred with aneurysm-like pooling of contrast media. Direct surgical observation confirmed a pseudoaneurysm formation. The pseudoaneurysm was likely formed by avulsion of a fine vessel during withdrawal of the stent retriever at a tortuous vessel.

Short-term rapid atrial pacing alters the gene expression profile of rat liver: Cardiohepatic interaction in atrial fibrillation.

BACKGROUND: Atrial fibrillation (AF) activates the coagulation system, leading to hypercoagulation of the blood. The liver is a major source of prothrombotic molecules. OBJECTIVE: This study aimed to clarify whether cardiohepatic interactions are involved in AF-related hypercoagulation. METHODS: We compared gene expression profiles of human liver tissue between patients with AF and sinus rhythm. An AF model was created by rapid atrial pacing (RAP) at a frequency of 1200 beats/min in anesthetized 10-week-old Sprague-Dawley rats. Livers, atria, and peripheral blood cells were collected and analyzed after 12 hours of RAP. RESULTS: DNA microarray analysis revealed marked changes in the gene expression profile of human liver of patients with AF. The extrinsic prothrombin activation pathway showed the most prominent change in 354 BioCarta pathways. Twelve hours of RAP also markedly altered the gene expression profile of rat liver. RAP markedly augmented the hepatic messenger RNA expression of fibrinogen chains, prothrombin, coagulation factor X, and antithrombin III. The augmented fibrinogen production by RAP was accompanied by increased of interleukin 6 (IL-6) messenger RNA expression in peripheral blood cells, enhanced monocyte chemoattractant protein-1 expression in the liver, infiltrated cluster of differentiation 11b-positive mononuclear cells in the liver, and enhanced signal transducer and activator of transcription 3 (STAT3) phosphorylation in the nuclei of hepatocytes. STAT3 phosphorylation and increased fibrinogen and coagulation factor X production by RAP were suppressed by pretreatment with IL-6 neutralizing antibody. CONCLUSION: Rapid atrial excitation mimicking paroxysmal AF remotely altered the hepatic gene expression of prothrombotic molecules. Increased fibrinogen expression in the liver by RAP was mediated by activation of the IL-6/STAT3 signaling pathway in the peripheral blood and liver.

Chronic Ischemia Induced by Woven Coronary Artery Anomaly with Typical Atrial Flutter: Insights from Multiple Imaging Devices.

A 75-year-old man with a 120-bpm tachycardia and typical atrial flutter was admitted. Echocardiography showed a dilated left ventricle with anterior and apical wall akinesia. Tachycardia was terminated with cavotricuspid isthmus ablation. Multiple imaging findings revealed a woven coronary artery anomaly (WCAA) in the left anterior descending artery. Stress myocardial perfusion imaging was performed after ablation in the sinus rhythm and revealed stress-induced ischemia and a fixed low uptake in the WCAA territory. WCAA is generally regarded as a benign condition; however, compromised blood flow within the anomaly, caused by tachycardia-related diastolic shortening, may induce ischemia.

Multiple anomalous systemic-pulmonary connections and coronary-pulmonary artery fistula associated with large aneurysms in an elderly woman.

We report the repair of a coronary artery fistula arising from the right coronary artery draining into the right pulmonary artery associated with multiple systemic-pulmonary connections.