Pulmonary Venous Ostia Research Articles

Impact of wall thickness on tissue cooling effect of cryoballoon ablation: Investigation using an experimental heart model

Abstract Background Understanding of the tissue cooling properties of cryoballoon ablation during pulmonary vein isolation is lacking. Purpose To delineate the depth of the tissue cooling effect during cryoballoon freezing at the pulmonary venous ostium. Methods A left atrial-pulmonary vein model, produced by a 3-dimensional printer using CT data from a patient, was constructed so that porcine thigh muscles of various thicknesses could be fixed and thermocouples could be fixed at locations corresponding to the epicardial side of the pulmonary vein ostium. The model was placed in a 37-degree water bath with a pulmonary vein water flow at a rate that mimicked biological blood flow, and the cryoballoon was advanced into the left superior vein until the vein was completely occluded. Cryofreezing was performed 5 times each for a porcine thigh muscle of 2-, 4-, and 6-mm thickness, and epicardial tissue cooling was monitored as assessed by the mean temperature of 12 evenly distributed thermocouples covering the roof region of the left superior vein. Results Epicardial tissue cooling effects were more in the order of 2-mm, 4-mm, and 6-mm thickness (Figure) with a mean temperature of -41.4 ± 4.2 for 2 mm, -33.0 ± 4.0 for 4 mm, and 8.0 ± 8.7 °C for 6 mm at 180 sec (p for trend < 0.0001). In addition, tissue temperature drops were steeper in thin muscle (maximum temperature drop per 5 s: 5.2 ± 0.9, 3.9 ± 0.7, 1.3 ± 0.7 °C, p for trend < 0.0001). Conclusion The cooling effect is weaker in the deeper layers during cryobaloon freezing, and longer freezing duration would be recommended in case of thick myocardium.

Impact of wall thickness on the tissue cooling effect of cryoballoon ablation.

Understanding of the tissue cooling properties of cryoballoon ablation during pulmonary vein (PV) isolation is lacking. The purpose of this study was to delineate the depth of the tissue cooling effect during cryoballoon freezing at the pulmonary venous ostium. A left atrial-PV model was constructed using a three-dimensional printer with data from a patient to which porcine thigh muscle of various thicknesses could be affixed. The model was placed in a 37°C water tank with a PV water flow at a rate that mimicked biological blood flow. Cryofreezing at the PV ostium was performed five times each for sliced porcine thigh muscle of 2, 4, and 6 mm thickness, and sliced muscle cooling on the side opposite the balloon was monitored. The cooling effect was assessed using the average temperature of 12 evenly distributed thermocouples covering the roof region of the left superior PV. Tissue cooling effects were in the order of the 2, 4, and 6 mm thicknesses, with an average temperature of -41.4 ± 4.2°C for 2 mm, -33.0 ± 4.0°C for 4 mm, and 8.0 ± 8.7°C for 6 mm at 180 s (P for trend <0.0001). In addition, tissue temperature drops were steeper in thin muscle (maximum temperature drop per 5 s: 5.2 ± 0.9°C, 3.9 ± 0.7°C, and 1.3 ± 0.7°C, P for trend <0.0001). The cooling effect of cryoballoon freezing is weaker in the deeper layers. Cryoballoon ablation should be performed with consideration to myocardial thickness.

Association of the left common ostium with clinical outcome after pulmonary vein isolation in atrial fibrillation.

IntroductionElectrical pulmonary vein isolation (PVI) is used for the invasive treatment of atrial fibrillation (AF). However, despite the procedure’s technical evolution, the rate of AF recurrence due to electrical reconnection of the PVs is high. The aims of this study was to assess the influence of left common pulmonary venous ostium (LCO) on clinical outcomes following PVI.MethodsRetrospective cohort of 254 patients who underwent the first procedure of PVI from the years 2013–2018 was assessed. Patients with persistent AF of long duration and extra-pulmonary focus associated with triggers for arrhythmia were excluded. Patients were stratified into two groups according to the presence of a LCO and received follow up for atrial tachyarrhythmia-free survival. The mean follow-up period was 28 ± 1.73 months.ResultsThe majority were men (68.5%), with a mean age of 54 ± 12 years. With respect to the atrial anatomy, LCO occurred in 23.6% of cases after pulmonary venous angiotomography. The arrhythmia-free survival rate was 79.5% in the follow-up period. The Cox regression model was utilized and the adjusted hazard ratio for LCO was 0.36 (95% CI 0.15–0.87; p = 0.02) in terms of age, body mass index, left atrium diameter, bi-directional blocking of the cavotricuspid isthmus, persistent AF, left ventricular ejection fraction adjusted model.ConclusionAnatomic abnormality with the presence of the LCO is present in a quarter of patients undergoing AF ablation, which is associated with a lower rate of arrhythmia recurrence in our population.

Unilateral accessory pulmonary venous ostium: A case report

Unilateral accessory pulmonary venous ostium: A case report

Variations in the Pulmonary Venous Ostium in the Left Atrium and Its Clinical Importance

During early embryonic development, absorption of pulmonary venous network by the left primitive atrial chamber results in opening of four pulmonary veins which drain independently into its chamber. The extent of absorption and hence, the number of pulmonary veins which open into the left atrium, may vary. As only few studies have been done, which have shown such variations, the present study was done to evaluate the possible variations in the pulmonary veins which opened into the left atrium. Fifty formalin fixed adult cadaveric hearts were studied for variations in the opening of the pulmonary veins into left atrium. Our results showed that 68% of the hearts which were studied, showed usual pattern of 2 pulmonary veins on either side, while remaining 32 % hearts showed variations in the number of pulmonary veins which opened. Twelve percent of the hearts showed 2 left and 3 right pulmonary veins, 14% of hearts showed 2 left and 1 right veins, 4% hearts showed 1 left and 2 right veins and 2% hearts showed 1 left and 4 right pulmonary veins opening into the left atrium. Knowledge on such variations gains significance in isolation for radiofrequency ablation as a treatment for atrial fibrillation.

Anatomical variation of pulmonary venous ostium and its relationship with atrial arrhythmia in the Saudi population

PurposeTo assess the anatomical variation of the ostial pattern of pulmonary veins observed on coronary computed tomography (CT) angiogram and to estimate the relationship of atrial arrhythmia with similar ostial variants in the Saudi population. Materials and methodsThin-section (0.625mm) contrast enhanced CT scans of 151 consecutive patients obtained over a span of a two-year period (January 2009–January 2011) for the diagnosis of ischemic heart disease, aortic regurgitation, infective endocarditis, aortic aneurysm, fibrosing mediastinitis, and pericardial defect. The retrospective study was focused on the identification of the number of venous ostia on either side of the left atrium and the drainage patterns of pulmonary veins. The frequency of each pattern was tabulated, and significance of their relationship with atrial arrhythmias was assessed with the X2 and Fisher’s exact tests. ResultsOut of 151 patients analyzed, 26 patients (17.2%) had anatomical variation of the pulmonary venous ostia. Atrial arrhythmia was recorded in 16 of 26(61.5%) patients (p=0.000). The association of higher anatomical variation of pulmonary venous ostia was recorded as higher (p=0.034) in the female group (n=15, 57.7%). ConclusionThe association between anatomically varied venous ostia and atrial arrhythmia was significant (p=0.000) with a significantly higher anatomical variation of pulmonary venous ostia in the female Saudi population (p=0.034).

PP-072 PERSISTENT LEFT SUPERIOR VENA CAVA WITH AGENESIS OF RIGHT SUPERIOR VENA CAVA: DIAGNOSIS OF RARE CONGENITAL CONCOMITANCE WITH TRANSESOPHAGEAL ECHOCARDIOGRAPHY

PP-070 LEFT COMMON PULMONARY VENOUS OSTIUM MIMICKING LEFT ATRIAL APPENDAGE ANEURYSM: ECHOCARDIOGRAPHIC MISDIAGNOSIS U.C. Yuksel, E. Yalcinkaya, E. Yildirim, T. Celik, U. Bozlar, M. Celik, Y. Gokoglan, B. Bugan, S. Firtina, A. Iyisoy, H.K. Kabul. Department of Cardiology, Gulhane Military Medical Academy, Ankara, Turkey; Department of Radiology, Gulhane Military Medical Academy, Ankara, Turkey; Department of Cardiology, Malatya Army Hospital, Malatya, Turkey; Department of Cardiology, Erzincan Army Hospital, Erzincan, Turkey Objective: The two most common pulmonary venous (PV) anomalies are the presence of aright middle PV and common left trunk. Herein, we report a patient with left common pulmonary venous ostium misdiagnosed as left atrial appendage aneurysm on echocardiography. Methods: A 67-year-old female with a medical history of hypertension admitted to our outpatient department for palpitation and dyspnea on exercise. She was advised to undergo routine echocardiography, which showed dilated left ventricle, decreased left ventricular ejection fraction (25%), moderate mitral regurgitation and left atrial appendage aneurysm. She was referred to cardiac computed tomographic angiography (CTA) for delineating anatomy. Results: CTA revealed an unusual pulmonary venous anomaly consisting of a left-sided common and unusually large ostium of left pulmonary veins draining to left atrium and normal coronaries. Conclusion: Cardiac anatomic variants has become increasingly important as the number of radiofrequency ablations has increased. The definite differentiation of pulmonary common ostium from an atrial appendage aneurysm could be made with transesophageal echocardiography, computed tomography and magnetic resonance imaging.

PP-071 RIGHT ATRIAL MASS AFTER SURGICAL REPAIR OF ATRIAL SEPTAL DEFECT: THROMBUS MASQUERADING AS A MYXOMA

PP-070 LEFT COMMON PULMONARY VENOUS OSTIUM MIMICKING LEFT ATRIAL APPENDAGE ANEURYSM: ECHOCARDIOGRAPHIC MISDIAGNOSIS U.C. Yuksel, E. Yalcinkaya, E. Yildirim, T. Celik, U. Bozlar, M. Celik, Y. Gokoglan, B. Bugan, S. Firtina, A. Iyisoy, H.K. Kabul. Department of Cardiology, Gulhane Military Medical Academy, Ankara, Turkey; Department of Radiology, Gulhane Military Medical Academy, Ankara, Turkey; Department of Cardiology, Malatya Army Hospital, Malatya, Turkey; Department of Cardiology, Erzincan Army Hospital, Erzincan, Turkey Objective: The two most common pulmonary venous (PV) anomalies are the presence of aright middle PV and common left trunk. Herein, we report a patient with left common pulmonary venous ostium misdiagnosed as left atrial appendage aneurysm on echocardiography. Methods: A 67-year-old female with a medical history of hypertension admitted to our outpatient department for palpitation and dyspnea on exercise. She was advised to undergo routine echocardiography, which showed dilated left ventricle, decreased left ventricular ejection fraction (25%), moderate mitral regurgitation and left atrial appendage aneurysm. She was referred to cardiac computed tomographic angiography (CTA) for delineating anatomy. Results: CTA revealed an unusual pulmonary venous anomaly consisting of a left-sided common and unusually large ostium of left pulmonary veins draining to left atrium and normal coronaries. Conclusion: Cardiac anatomic variants has become increasingly important as the number of radiofrequency ablations has increased. The definite differentiation of pulmonary common ostium from an atrial appendage aneurysm could be made with transesophageal echocardiography, computed tomography and magnetic resonance imaging.

Anatomical variations of pulmonary venous drainage in Thai people: multidetector CT study.

Objective:To evaluate the patterns of pulmonary venous drainage into the left atrium and to determine the frequency of each variant of pulmonary venous anatomy.Materials and methods:After institutional review board approval (No. 09JUL011148), 300 studies of thoracic multidetector computed tomography were retrospectively reviewed for the anatomical features of the pulmonary vein and its drainage pattern into the left atrium. The percentage of each pattern was calculated.Results:The anatomy of pulmonary venous drainage in 300 patients (150 male and 150 female, mean age 60.16 years) showed some variation. In the right pulmonary vein, the most common drainage pattern was two ostia (90.33%), followed by three to five ostia (6.33%) and a single ostium (3.33%). There were one or two separate middle lobe vein ostia in groups of more than two openings. On the left side, there were two patterns; a single venous ostium (59%) was much more common than two ostia (41%). In both right and left pulmonary veins, there were five cases (2 male, 3 female) that had a single pulmonary venous ostium, bilaterally. However, there were only 17 cases (5.67%), out of 300 enrolled in this study, that had bilateral pulmonary venous ostial variations.Conclusion:A classification system to succinctly describe pulmonary venous drainage patterns was developed. In left-sided drainage, a single left pulmonary ostium was the most common variation. The right-sided venous drainage varied more in both number and pattern than those of the left side; nevertheless, bilateral pulmonary venous ostial variation was not frequently found.

How to perform antral pulmonary venous isolation using the cryoballoon

h s n r s i p p c a e o Introduction This article describes our current practice, clinical outcomes, and future directions for the use of balloon cryoablation for the treatment of atrial fibrillation. Consensus exists that pulmonary venous (PV) isolation, preferably at an antral level, should be the cornerstone of any atrial fibrillation (AF) ablation procedure. However, most operators agree that the widely used technique of point-by-point ablation around PV antra is not ideal. Novel catheter designs that deliver circumferential ablation centered on PV ostia have the potential to reduce procedural times and complexity while delivering at least comparable clinical outcomes. One such technology, the cryoablation balloon, has been in use in Europe since 2005 and recently received U.S. Food and Drug Administration approval in 2010 for ablation of paroxysmal atrial fibrillation (PAF). In this article, we review the role of percutaneous cryotherapy for AF with an emphasis on our clinical experience with the cryoballoon.

The Common Trunk of the Left Pulmonary Vein Injured Incidentally During Lung Cancer Surgery

We report a case in which the common trunk of the left pulmonary vein was injured incidentally due to a misunderstanding of the anatomy. After cutting the trunk, we recognized that the vessel included not only the superior but also the inferior component of the pulmonary vein. The cut end of the trunk and the left atrium were successfully anastomosed without any surgical morbidity. Although we retrospectively determined that the common trunk was visualized on preoperative computed tomography, we missed this finding during the preoperative evaluation. Furthermore, because we used the endostapler to cut the vessel, exposure of the pulmonary hilum was too short to identify the anomaly correctly. In the era of the endoscopic devices, exposure of the anatomical structures at surgery has become more limited, resulting in a tendency to misunderstand the anatomy during surgery. Because the common trunk of the left pulmonary vein occurs in 14% of patients demonstrating anatomical variations, thoracic surgeons should be aware of this type of anomaly not only before but also during surgery, and meticulous intraoperative confirmation of the vascular anatomy is required when using endoscopic devices.

Catheter Ablation of Atrial Fibrillation

A B S T R A C T Catheter ablation of atrial fibrillation (AF) has become a viable therapeutic alternative in symptomatic patients resistant to antiarrhythmic drugs. Since the first report of catheter ablation a decade ago, several techniques have evolved. These techniques reflect principal mechanisms of AF. Besides segmental electrical isolation, circumferential ablation around the pulmonary venous ostia with a support of the 3D electroanatomical mapping system appears to be the most frequently used techniques. Some authors use various combinations of these techniques including guidance with intracardiac echocardiography (ICE). Most recently, ablation within areas of fractionated electrograms during AF has been proposed. The aim of this review is to summarize briefly current techniques, their efficacy and safety.

Characteristics in Image Integration System Guiding Catheter Ablation of Atrial Fibrillation with a Common Ostium of Inferior Pulmonary Veins

Common ostium of the inferior pulmonary veins (PVs) is a kind of unusual variation in pulmonary venous drainage to the left atrium (LA), whose feature of anatomy, electrophysiology, and catheter ablation is rarely demonstrated, and the consecutive series of research for catheter ablation of atrial fibrillation (AF) in patients with that anomaly have not been reported. A total of 1,226 patients with drug-refractory AF received magnetic resonance angiography (MRA) or multidetector computed tomography (MDCT) scan before ablation. Electrophysiological mapping was used to detect the focal triggers in paroxysmal AF. Basic catheter ablation strategy was circumferential PV isolation with "tricircle" under the guidance of image integration system: two circles surround two superior PVs, and the other surround the common trunk. LA and PVs reconstruction by image integration system showed a common pulmonary venous ostium of the right and left inferior PVs before ablation in 11 patients (0.9%). This anomaly could be classified into two types: type A without a short common trunk of inferior PVs and type B with a short common trunk. Fifty-seven percent paroxysmal AF was revealed focal triggers in the common ostium. The success rate of that strategy was 90%. Common ostium of inferior PVs could be classified into two types according to the presence of a short common trunk or not. The common ostium was usually an important triggering focus in paroxysmal AF. Catheter ablation strategy of circumferential PV isolation with "tricircle" under the guidance of image integration system would be a good choice.

Common Pulmonary Venous Ostium of the Right and Left Inferior Pulmonary Veins: An Unusual Pulmonary Vein Anomaly Depicted with 64‐Slice Cardiac Computed Tomography

Common Pulmonary Venous Ostium of the Right and Left Inferior Pulmonary Veins: An Unusual Pulmonary Vein Anomaly Depicted with 64‐Slice Cardiac Computed Tomography

Magnetic Resonance Angiography of Pulmonary Veins: Implications for Catheter Ablation of Atrial Fibrillation

Catheter ablation of atrial fibrillation (AF) requires exact anatomical information about pulmonary venous (PV) ostia. In this study, anatomy of pulmonary veins (PVs) was assessed using three-dimensional (3D) reconstructions of magnetic resonance angiography (MRA). Contrast-enhanced MRA of the PVs was performed in 40 patients (mean age 53 +/- 9 years) with paroxysmal (30 patients) or persistent (10 patients) AF, scheduled for circumferential ablation around PV ostia. PV ostial anatomy and diameters were evaluated from multiplanar reconstructions and compared with 3D reconstructions. Thirty (75%) patients presented with a common left-sided antrum (21 short and 9 long trunk), while additional PVs were found on right side in 23%. PV ostia were oblong in shape (mean diameters 17.0 +/- 4.3 vs 10.5 +/- 2.5 mm by two-dimensional (2D) measurements, and 20.8 +/- 7.6 mm vs 12.9 +/- 3.3 mm by 3D reconstruction, in long and short axis, respectively). There was a correlation between measurements obtained from 2D and 3D images, although 3D imaging provided slightly larger diameters. MRA with 3D reconstructions is an important technique for preprocedural assessment of PVs that allows full understanding of their anatomy and size. This information may be important for selection of appropriate tools.

Development of the pulmonary vein in the American alligator (Alligator mississippiensis).

The origin of the embryonic common pulmonary vein in terrestrial vertebrates is still uncertain. Most earlier studies in nonhuman embryos describe the vein as entering the sinus venosus. The currently prevailing view, however, based largely on the study of human material, is that the embryonic common pulmonary vein is associated with the left atrium from its inception. We recently observed the pulmonary vein entering the sinus venous part of the right atrium in several normal dog embryos of a stage comparable to horizon XIV in man (Streeter: Contrib. Embryol. Carnegie Inst. Wash., 31:53, 1945). In slightly older specimens the vein entered the left atrium just to the left of septum primum. This observation, and the fact that some atrial septal and pulmonary venous anomalies in man still await a plausible pathogenetic explanation, stimulated a restudy of the origin of the vein. The alligator was used because we already had prepared a large number of closely graded serially sectioned embryos for other purposes. Wax plate reconstructions clearly showed that the common pulmonary vein entered the left side of the sinus venosus. With the formation of the atrial septum, this part of the sinus venosus is "pinched off" and becomes incorporated into the left atrium, thus transferring the pulmonary venous ostium to that atrium.

Pulmonary venous flow pattern--its relationship to cardiac dynamics. A pulsed Doppler echocardiographic study.

We studied the physiology of pulmonary venous flow in 13 normal subjects and five patients with atrial rhythm disorders and atrioventricular conduction disturbances with pulsed Doppler and two-dimensional echocardiography. The left atrium, mitral valve, and pulmonary venous ostia were visualized through the apical four-chamber view. Mitral and pulmonary venous flows were obtained by placing the Doppler sample volume at the appropriate orifice. Pulmonary venous flow was biphasic: a rapid filling wave was observed during systole when the mitral valve was closed; a second wave was observed in diastole during the rapid ventricular filling phase of mitral flow, but was significantly delayed. In patients without atrial contraction (atrial fibrillation and sinoatrial standstill), the initial rapid filling was greatly diminished and only the second diastolic wave appeared to contribute to left atrial filling. In patients with high-grade atrioventricular block, each atrial contraction was followed by a surge in flow from the pulmonary veins. These results are consistent with data obtained from invasive measurements in both dogs and man, and confirm the validity of the use of pulsed Doppler echocardiography in the study of pulmonary venous flow. We suggest that pulmonary venous flow is influenced by dynamic changes in left atrial pressure created by contraction and relaxation of the atrium and ventricle. The initial peak in pulmonary venous flow occurs with atrial relaxation simultaneously with the reduction of left atrial pressure, and the second peak occurs with left ventricular relaxation and rapid transmitral filling of the ventricle.