Electroanatomic substrate of idiopathic left ventricular tachycardia: unidirectional block and macroreentry within the purkinje network.

BACKGROUND: An abnormal potential (retroPP) from the left posterior Purkinje network has been demonstrated during sinus rhythm (SR) in some patients with idiopathic left ventricular tachycardia (ILVT). We hypothesized that this potential can specifically be identified and be a critical substrate for ILVT. METHODS AND RESULTS: In 9 patients with ILVT and 6 control patients who underwent mapping of the left ventricle during SR using 3-dimensional electroanatomic mapping, an area with retroPP was found within the posterior Purkinje fiber network only in patients with ILVT. The earliest and latest retroPP was 185.4+/-57.4 and 465.2+/-37.3 ms after Purkinje potential; in the other patient with ILVT, an entire left ventricle mapping demonstrated a slow conduction area and passive retrograde activation along the posterior fascicle during ILVT. ILVT was noninducible in 3 patients after SR mapping. Diastolic potentials critical for ILVT during ILVT coincided with the earliest retroPP during SR in 7 patients. Mechanical termination of ILVT occurred in 5 patients. A single radiofrequency pulse was applied at the site with mechanical translation in 5 patients and the site with diastolic potential in 2 patients, and 3 radiofrequency pulses were delivered to the site with the earliest retroPP in the other 3 patients without inducible ILVT after SR mapping. No ILVT was inducible during control stimulation, and none recurred during follow-up of 9.1+/-5.1 months. CONCLUSION: In patients with ILVT, abnormal retroPP within the posterior Purkinje fiber network is a common finding. The earliest retroPP critical for ILVT substrate can be used for guiding successful ablation.

Spontaneous retraction of an intramyocardial dissecting hemorrhage and multiple left ventricular thrombus formations in subacute myocardial infarction and antiphospholipid syndrome: a case report with long-term follow-up.

This report describes a 68-year-old patient with a subacute myocardial infarction and antiphosholipid syndrome. He developed an intramyocardial dissecting hemorrhage involving the left ventricular apex and multiple left ventricular thrombus formations, documented by contrast echocardiography and magnetic resonance imaging. By use of transthoracic echocardiography, spontaneous retraction of the dissecting hemorrhage could be detected. Severe coronary 3-vessel disease was successfully treated by coronary artery bypass grafting. During follow-up of 16 months, the dissecting hematoma could not been detected. Under initiation of anticoagulant treatment with Coumadin, the patient was in stable clinical condition and improved in New York Heart Association class from III to II. The pathophysiology, diagnosis, and management of this potentially highly lethal complication is reviewed.

Transesophageal echocardiography: a screening method for pulmonary vein stenosis after catheter ablation of atrial fibrillation.

AIMS: Pulmonary vein (PV) stenosis has been described as a complication after catheter ablation of atrial fibrillation. The aim of the study was to investigate the diagnostic role of transesophageal echocardiography (TEE) in the assessment of PV stenosis. METHODS: Ninety-one patients (71 men, mean age 57+/-16years), initially treated by catheter ablation of atrial fibrillation, underwent re-ablation because of arrhythmia recurrences. PV angiograms and TEE were performed before the first and second ablation. PVs were analysed in an intraindividual comparison by measurements of mean and peak flow velocity and of velocity time integrals and diameters. PV angiograms served as standard for assessment of PV stenosis. RESULTS: Sixteen of 91 patients developed PV stenoses as a consequence of the first ablation (13 mild PV stenoses, 4 moderate PV stenoses). All patients with PV stenosis were asymptomatic. In moderate PV stenosis (50-70%) a significant increase of blood flow parameters, reduction of vessel diameter, inhomogeneous blood flow and aliasing were demonstrated by TEE. Using quantitative TEE criteria moderate PV stenosis could be identified with a sensitivity of 84% and specificity of 98%. Detection of mild PV stenosis (30-50%) is challenging (sensitivity of 48% and specificity of 75%). CONCLUSIONS: TEE identifies significant PV stenosis by assessment of flow characteristics and vessel diameter and can thereby be used as a follow-up tool after catheter ablation of atrial fibrillation.

Total pulmonary vein occlusion as a consequence of catheter ablation for atrial fibrillation mimicking primary lung disease.

INTRODUCTION: Catheter ablation has recently been used for curative treatment of atrial fibrillation. METHODS AND RESULTS: Three of 239 patients who underwent ablation close to the pulmonary vein (PV) ostia at our institute developed severe hemoptysis, dyspnea, and pneumonia as early as 1 week and as late as 6 months after the ablation. Because the patients were arrhythmia-free, the treating physician initially attributed the symptoms to new-onset pulmonary disease (e.g., bronchopulmonary neoplasm). After absent PV flow was confirmed by transesophageal echocardiography, transseptal contrast injection depicted a totally occluded PV in all three patients. Successful recanalization, even in chronically occluded Pvs, was performed in all patients. During follow-up, Doppler flow measurements by transesophageal echocardiography demonstrated restenosis in all primarily dilated PV, which led to stent implantation. CONCLUSION: PV stenosis/occlusion after catheter ablation of atrial fibrillation occurs in a subset of patients. However, because in-stent restenosis occurred in two patients after 6 to 10 weeks, final interventional strategy for PV stenosis or occlusion remains unclear. To prevent future PV stenosis or occlusion, a decrease in target temperature and energy of radiofrequency current or the use of new energy sources (ultrasound, cryothermia, microwave) seems necessary.