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At least 91 records · Page 5Linked to original sources

Extrapericardial pulmonary vein clamp technique for pulmonary arteriovenous fistula: report of a case.

The major concern when operating on a patient with a neurologically symptomatic pulmonary arteriovenous fistula (PAVF) is how to prevent a thromboembolic event during surgery. We describe a new technique whereby the extrapericardial pulmonary vein is clamped before transecting the afferent and efferent vessels of the fistula. The potentially pooled clots that can form while manipulating lung are stopped by the clamp. Before the extrapericardial pulmonary vein is declamped, one of the drainage veins is incised halfway and the pooled blood containing the potential clots is completely washed out. We successfully performed segmentectomy using this technique in a 66-year-old man with chronic left hemianopia and a large PAVF in the left anteromedial and lateral basal segments, and no thromboembolic events occurred.

Aged↗

T-type calcium current in electrical activity of cardiomyocytes isolated from rabbit pulmonary vein.

INTRODUCTION: Pulmonary veins (PVs) are known to initiate paroxysmal atrial fibrillation. T-type calcium current (I(Ca-T)) has a role in normal and abnormal automaticity of cardiomyocytes. The aim of this study was to evaluate whether I(Ca-T) contributes to PV electrical activity. METHODS AND RESULTS: By whole-cell clamp techniques in rabbit myocytes, I(Ca-T) was identified in 12 (39%) of 31 PV cardiomyocytes with pacemaker activity, 2 (9%) of 23 PV cardiomyocytes without pacemaker activity, and 2 (15%) of 13 atrial myocytes (P < 0.05). Maximum I(Ca-L) and I(Ca-T) densities from PV cardiomyocytes with pacemaker activity were 6.87 +/- 2.17 pA/pF and 1.38 +/- 0.69 pA/pF, respectively. Nickel (40 microM) decreased the spontaneous activity in 5 (36%) of 14 PV cardiomyocytes (3.1 +/- 0.6 Hz vs 2.2 +/- 0.5 Hz, P < 0.05), reduced the amplitudes of delayed after depolarization from 13 +/- 1 mV to 7 +/- 1 mV (n = 4, P < 0.05) and inhibited transient inward currents from 1.2 +/- 0.2 pA/pF to 0.7 +/- 0.1 pA/pF (n = 11, P < 0.01). CONCLUSIONS: We conclude that I(Ca-T) contributes to PV pacemaker activity and triggered activity, which are of functional importance in PV arrhythmogenesis.

Action Potentials↗

Adenosine restores atrio-venous conduction after apparently successful ostial isolation of the pulmonary veins.

AIMS: Pulmonary vein (PV) isolation is a curative treatment for patients with atrial fibrillation. The aim of this study was to evaluate prospectively the effects of adenosine administration on the PV activity and atrio-venous conduction after PV isolation. METHODS AND RESULTS: Twenty-nine patients (21 m; age: 55+/-8 years) were submitted to ostial PV isolation guided by basket catheter recordings. After successful isolation, the effects of a 12 mg intravenous bolus of adenosine were tested in 62 PVs. In 22/62 PVs (35%), left atrium (LA)-to-PV conduction was transiently (16.6+/-7.1 s, range: 3.8-27.9 s) or permanently (3 PVs) restored in response to adenosine administration. The prevalence of this phenomenon was 39% in left superior PVs, 43% in right superior PVs, and 22% in left inferior PVs (p=0.365). It occurred more frequently in the presence of dissociated PV activity (11/15 PVs, 73% vs. 11/47 PVs, 23%; p=0.002), whereas it was not influenced by the median duration of the radiofrequency current (RFC) delivery for each PV [19 (IQR: 12-26) min vs. 16 (IQR: 11-24) min: p=0.636]. A lengthening or shortening of the LA-PV conduction time was observed at LA-PV conduction appearance and disappearance in 36% and 55% of the cases, respectively. Further RFC applications (median: 5.5 min, IQR: 4-11 min) at the residual conduction breakthrough(s) indicated by the basket catheter recordings definitively eliminated adenosine-induced recovery of LA-PV conduction in all cases. Finally, when present, intrinsic PV discharge was invariably depressed by adenosine administration. CONCLUSIONS: Adenosine may transiently or permanently re-establish LA-PV conduction after apparently successful PV isolation. This phenomenon is abolished by additional RFC delivery. However, its possible influence on the clinical results of PV ablation must be evaluated by properly designed, randomized studies.

Adenosine↗

Pulmonary vein isolation under direct visual identification of the left atrium-pulmonary vein junction using intra-cardiac echography.

INTRODUCTION: Intra-cardiac echocardiography (ICE) which has some benefits, can be used to obtain detailed anatomy of the heart chambers or large vessels, and the catheter positions, and it has been considered useful for improving the outcome of the ablation. In the present study, we performed pulmonary vein isolation (PVI) under real time monitoring of ICE imaging utilizing an ICE catheter placed at the junction of the left atrium (LA) and PVs (LA-PV junction). METHODS: PVI for atrial fibrillation (AF) was performed in 30 cases with drug-resistant AF (mean age: 66-years-old; including 22 males). An ICE catheter utilizing a 9 MHz frequency was inserted into the LA via the atrial septum, and placed at the LA-PV junction. Circumferential ablation was performed in the LA outside of the PV ostium, encircling both the superior and inferior ostia together under ICE imaging. RESULTS: The anatomy of the LA to the PVs and catheter sites were clearly identified by the ICE during the procedure, which enabled a precise and safe catheter manipulation with minimal fluoroscopy. Further, the wall thickness of the PV and LA, and position of the esophagus could be obtained by ICE, facilitating care in adjusting the power and/or duration of the current delivery. CONCLUSION: ICE imaging of the LA-PV junction permitted real time monitoring of the target sites for PVI during the ablation procedure, and was considered a useful technique for performing PVI.

Aged↗

[Successful repair of a newborn case with total anomalous pulmonary venous connection presenting hemodynamically common pulmonary vein atresia].

Common pulmonary vein atresia is a very rare from of congenital cardiac anomaly in which the common chamber of pulmonary veins has no direct communication to the heart or systemic venous system. We report here on one-day-old boy with total anomalous pulmonary venous connection having severe stenosis (sized less than one millimeter in diameter) of vertical vein between common pulmonary vein and superior vena cava. His anatomic feature was considered as a spectrum between common pulmonary vein atresia and total anomalous pulmonary venous connection because of almost atretic draining vertical vein. His clinical presentation and hemodynamic characteristics were the same as common pulmonary vein atresia. He underwent an emergent anastomosis of common pulmonary vein to left atrium at 33 hours after birth under cardiopulmonary bypass, cross-sectional echocardiography and Doppler color mapping. He was discharged home two months after the surgery. Cardiac catheterization after six months revealed normal cardiac function without any evidence of pulmonary venous chamber stenosis. To improve the outcome of surgical intervention for this life-threatening cardiac anomaly, immediate the precise diagnosis using echocardiography followed by emergent surgical correction is in dispensable.

Cardiac Surgical Procedures↗

[Reoperation after correction of total anomalous pulmonary venous connection: particularly for postoperative pulmonary vein stenosis].

Postoperative pulmonary vein stenosis is a major complication after the correction of the total anomalous pulmonary venous connection. Six patients developed this complication 2 to 3 months after surgery. Five underwent reoperation (3 had the third operations) with only one survivor. Risk factors for developing the stenosis were 1. small common pulmonary vein with small branches occurring in the patients with the ages at the operation below 2 days and accordingly with the infradiaphragmatic connection and 2. Y-shaped common pulmonary vein with the confluence situated far below the left atrium. Turbulence seemed the major cause of the intimal thickening occurring in the common pulmonary vein shortly distant from the orifices of the branches. Typically the anastomotic orifice was not narrowed. Relief of the stenosis was done by the excision of the hypertrophied intimal tissue frequently cutting into the branches. Severe stenosis recurred in 4 patients necessitating another operation in 3 patients which was fatal in two. Prevention is important. Creation of a large anastomosis with the incision not extending into the branches and the use of the absorbable suture materials were effective. In the infradiaphragmatic connection incorporation of the divided stump of the descending vein into the anastomosis and a T-shaped incision of the left atrium were also important.

Constriction, Pathologic↗

Pulmonary vein isolation using transvenous catheter cryoablation for treatment of atrial fibrillation without risk of pulmonary vein stenosis.

OBJECTIVES: We sought to evaluate the efficacy and safety of pulmonary vein (PV) isolation using transvenous cryoablation for the treatment of atrial fibrillation (AF). BACKGROUND: Although electrical isolation of PVs with radiofrequency energy for the treatment of AF is feasible, it is associated with a significant risk of PV stenosis. Cryoablation is a new alternative therapy allowing ablation of tissue while preserving its underlying architecture. METHODS: In 52 patients with paroxysmal (n = 45) or persistent (n = 7) AF, PV isolation using the CryoCor cryoablation system (CyroCor Inc., San Diego, California) with a 10F deflectable transvenous catheter was performed as guided by ostial PV potentials. Cryoablation was applied twice at each targeted site (2.5 to 5 min/application). Computed tomography (CT) of the thorax was performed at baseline and at 3 and 12 months to evaluate for PV stenosis. RESULTS: All targeted PVs were completely isolated in 49 (94%) of 52 of patients. Of 152 PVs targeted, 147 (97%) were successfully isolated (mean 3.0 PVs isolated per patient). After a mean period of 12.4 +/- 5.5 months of follow-up, 37 (71%) of 52 patients had no recurrence of AF or were clinically improved, including 29 patients (56%) who had no recurrence of AF with (n = 11) or without the use of anti-arrhythmic drugs. At 3 and 12 months, the CT scan showed no evidence of PV stenosis associated with cryoablation in any patients. CONCLUSIONS: Transvenous catheter cryoablation is an effective method to create PV electrical isolation for the treatment of AF. A clinically satisfactory result can be achieved in 71% of patients with AF, without the risk of PV stenosis.

Adult↗

Prevalence of pulmonary vein disconnection after anatomical ablation for atrial fibrillation: consequences of wide atrial encircling of the pulmonary veins.

AIMS: Anatomical and wide atrial encircling of the pulmonary veins (PVs) has been proposed as a cure of atrial fibrillation (AF). We evaluated the acute achievement of electrical PV isolation using this approach. In addition, the consequences of wide encircling of the PVs with isolation were assessed. METHODS AND RESULTS: Twenty patients with paroxysmal AF were studied. Anatomically guided ablation was performed utilizing the CARTO system to deliver coalescent lesions circumferentially around each PV to produce a voltage reduction to <0.1 mV, with the operator blinded to recordings of circumferential PV mapping. After achieving the anatomical endpoint, the incidence of residual conduction and the amplitude and conduction delay of residual PV potentials were determined. Electrical isolation of the PV was then performed and the residual far-field potentials evaluated. Individual PV ablation was performed in all PVs. Anatomically guided PV ablation was performed for 47.3+/-11 min, after which 44 (55%) PVs were electrically isolated. In the remaining 45%, despite abolition of the local potential at the ablation site, PV potentials [amplitude 0.2 mV (range 0.09-0.75) and delay of 50.3+/-12.6 ms] were identified by circumferential mapping. After electrical isolation (12.2+/-11.7 min ablation), 55 (69%) PVs demonstrated far-field potentials; with a greater incidence (P=0.015) and amplitude (P=0.021) on the left compared with the right PVs. At 13.2+/-8.3 months follow-up, 13 patients (65%) remained arrhythmia-free without anti-arrhythmics. In four patients (20%), spontaneous sustained left atrial macrore-entry required re-mapping and ablation. Macrore-entry was observed to utilize regions around or bordering the previous ablation as its substrate. CONCLUSION: Anatomically guided circumferential PV ablation results in apparently coalescent but electrically incomplete lesions with residual conduction in 45% of PVs. Wide encircling of the PVs was associated with left atrial macrore-entry in 20% of patients.

Atrial Fibrillation↗

Repair of congenital and acquired pulmonary vein stenosis.

BACKGROUND: Congenital pulmonary vein stenosis is a rare cause of obstruction of pulmonary venous blood flow with a high mortality. Acquired pulmonary vein stenosis is an equally serious condition. METHODS: Eight patients (age range, 3 months to 43 years; median age, 1.5 years) underwent surgical relief of pulmonary vein stenosis. Two had congenital pulmonary vein stenosis, 5 had pulmonary vein stenosis that was acquired after surgical treatment of total anomalous pulmonary venous connection, and 1 had pulmonary vein stenosis associated with idiopathic mediastinal fibrosis and calcification. RESULTS: One infant died 2 months after correction of acquired pulmonary vein stenosis. At follow-up extending to 16 years (median follow-up, 6.5 years), 6 patients are in New York Heart Association functional class I, and 1 patient is in class II. CONCLUSIONS: In view of the dismal natural history of untreated pulmonary vein stenosis, prompt surgical relief of the stenosis may be a rewarding undertaking.

Adolescent↗

Pulmonary vein morphology in patients with paroxysmal atrial fibrillation initiated by ectopic beats originating from the pulmonary veins: implications for catheter ablation.

BACKGROUND: Successful ablation of ectopic beats originating from the pulmonary veins (PV) could eliminate paroxysmal atrial fibrillation (PAF). However, information about the structure of the PV in patients with PAF that is initiated by PV ectopic beats has not been reported. METHODS AND RESULTS: We studied the morphology of the PVs and measured their diameters in 3 groups of patients. Group I included 52 patients (aged 66+/-14 years; 44 men) with focal atrial fibrillation (AF) from the PVs. Group II included 8 patients (aged 50+/-10 years; 3 men) with focal AF from the superior vena cava or cristal terminalis. Group III included 23 control patients (aged 55+/-16 years; 17 men). Of the control patients, 11 had AV node and 12 had AV reentrant tachycardia. After an atrial transseptal procedure, selective PV angiography using a biplane system with a right anterior oblique view of 30 degrees, a left anterior oblique view of 60 degrees, and a cranial angle of 20 degrees was performed. The ostial and proximal portions of the right and left superior PVs (RSPV and LSPV) were significantly dilated in group I patients compared with those in groups II and III. Furthermore, the ostia of the RSPV and LSPV were significantly dilated in group II compared with group III patients. However, the mean diameters of the inferior PVs were similar between the 3 groups. Comparisons of the individual PV diameters among the 3 subgroups of group I (which was divided according to where the ectopic focus was located) showed nonselective dilatation of the PV. CONCLUSIONS: Nonspecific dilatation of the ostia and proximal portion of superior PVs were found in patients with PAF initiated by ectopic beats from the superior PVs.

Adult↗

Anatomical observations of the pulmonary veins with intracardiac echocardiography and hemodynamic consequences of narrowing of pulmonary vein ostial diameters after radiofrequency catheter ablation of atrial fibrillation.

Intracardiac echocardiography was used to explore pulmonary venous (PV) anatomy and to monitor PV stenosis in 31 patients referred for radiofrequency catheter ablation at PV ostia. Interindividual variations in PV anatomy and insertion in the left atrium were observed. Narrowing of PV ostia after radiofrequency catheter ablation did not produce significant hemodynamic changes.

Adult↗