Phrenic nerve palsy during ablation of atrial fibrillation using a 28-mm cryoballoon catheter: predictors and prevention

Purpose: The purposes of this study were to determine whether predictors of phrenic nerve palsy (PNP) exist and to test whether a standardized ablation protocol may prevent PNP during cryoballoon (CB) ablation using the 28mm CB. Methods: Three-dimensional (3D) geometry of the pulmonary veins (PV) and their relationship to the superior vena cava (SVC) was analyzed. Phrenic nerve (PN) stimulation was performed during ablation of the right-sided PVs with a 28-mm CB. The freezing cycle was immediately terminated in case of loss of PN capture. Results: Sixty-five patients (age, 58 ± 11years; ejection fraction, 0.59 ± 0.06; left atrial size, 40 ± 5mm) with paroxysmal atrial fibrillation were included. No persistent PNP was observed. Transient PNP occurred in 4 of 65 patients (6%). PN function normalized within 24h in all four patients. A short distance between the right superior PV and the SVC was significantly associated with PNP, but left atrial and 3D PV anatomy were not. Low temperature early during the freezing cycle (<−41°C at 30s) predicted PNP with a sensitivity and a specificity of 100 and 98%, respectively. Conclusion: The anatomical relationship between the right superior PV and the SVC is a preprocedural predictor for the development of transient PNP, and low temperature early during ablation at the right superior PV is a sensitive warning sign of impending PNP. Despite the use of the 28mm CB, transient PNP occurred in 6% of patients undergoing CB ablatio

The Relationship of Left Ventricular Trabeculation to Ventricular Function and Structure Over a 9.5-Year Follow-Up The MESA Study

Left ventricular (LV) trabeculation is highly variable among individuals and is increased in some diseases (e.g., congenital heart disease or cardiomyopathies), but its significance in population-representative individuals is unknown

Trabeculated (non-compacted) and compact myocardium in adults: the multi-ethnic study of atherosclerosis

BACKGROUND: A high degree of non-compacted (trabeculated) myocardium in relationship to compact myocardium (T/M ratio >2.3) has been associated with a diagnosis of left ventricular non-compaction (LVNC). The purpose of this study was to determine the normal range of the T/M ratio in a large population-based study and to examine the relationship to demographic and clinical parameters. METHODS AND RESULTS: The thickness of trabeculation and the compact myocardium were measured in eight LV regions on long axis cardiac magnetic resonance (CMR) steady-state free precession cine images in 1000 participants (551 women; 68.1±8.9 years) of the Multi-Ethnic Study of Atherosclerosis cohort. Of 323 participants without cardiac disease or hypertension and with all regions evaluable 140 (43%) had a T/M ratio >2.3 in at least one region; in 20/323 (6%), T/M>2.3 was present in more than two regions. Multivariable linear regression model revealed no association of age, gender, ethnicity, height and weight with maximum T/M ratio in participants without cardiac disease or hypertension (p>0.05). In the entire cohort (n=1000) LVEF (β=−0.02/%; p=0.015), LVEDV (β=0.01/ml; p=<0.0001) and LVESV (β=0.01/ml; p<0.001) were associated with maximum T/M ratio in adjusted models while there was no association with hypertension or myocardial infarction (p>0.05). At the apical level T/M ratios were significantly lower when obtained on short- compared to long-axis images (p=0.017). CONCLUSIONS: A ratio of trabeculated to compact myocardium of more than 2.3 is common in a large population based cohort. These results suggest reevaluation of the current CMR criteria for LVNC may be necessary

Functional results after chest wall stabilization with a new screwless fixation device

OBJECTIVES This is the experience with the Stratos system in two surgical centres for the management of two types of rib fractures: flail chest and multiple dislocated rib fractures with significant chest wall deformity. METHODS From January 2009 to May 2012, 94 consecutive patients were included. Selected indications were extended anterolateral flail chest (n = 68) and dislocated painful rib fractures (n = 26). The open reduction internal fixation (ORIF) system consists of flexible titanium rib clamps and connecting plates. The postoperative course was assessed. Clinical and functional outcomes were evaluated at 6 months. Functional assessment consisted of measurement of the functional vital capacity (FVC) and magnetic resonance imaging (MRI) examination with determination of the radiological vital capacity (rVC) in patients with a flail chest. RESULTS The median operation time and length of hospital stay were 122 min and 19 days, respectively, in patients with a flail chest, and 67 min and 11 days, respectively, in patients with dislocated painful rib fractures. The morbidity rate was 6.4% and the overall 30-day mortality rate was 1.1%. Clinical evaluation and pulmonary function testing at 6 months revealed no deformity of the chest wall, symmetrical shoulder girdle mobility in 88% and a feeling of stiffness on the operated side in 19% of the patients operated for a flail chest. Median ratio of FVC was 88%, not suggesting any restriction after stabilization. MRI was performed in 53% (36 of 68) of the patients with a flail chest. The analysis of the rVC showed, on average, no clinically relevant restriction related to the operation, with a mean rVC of the operated relative to the non-operated side of 92% (95% confidence interval: 83, 100). Stabilization of more than four ribs was associated with a lower median rVC than stabilization of four or less ribs. CONCLUSIONS Our results suggest that stabilization of the chest wall with this screwless rib fixation device can be performed with a low morbidity and lead to early restoration of chest wall integrity and respiratory pump function, without clinically relevant functional restriction. Owing to the simplicity of the fixation technique, indications for stabilization can be safely enlarged to selected patients with dislocated and painful rib fracture

Left atrial volume quantification using cardiac MRI in atrial fibrillation: comparison of the Simpson’s method with biplane area-length, ellipse, and three-dimensional methods

PURPOSELeft atrial volume is an important predictor of future arrhythmias, and it can be assessed by several different methods. Simpson’s method is well accepted as a reference standard, although no standardization exists for cardiac magnetic resonance (CMR). We aimed to compare the estimations of left atrial volumes obtained by the Simpson’s method with three other methods. MATERIALS AND METHODSEighty-one consecutive patients referred for CMR imaging between February 2007 and May 2010 were included in the study (47 males; mean age, 59.4±11.5 years; body mass index, 26.3±3.7 kg/m2). Left atrial volume measurements were performed using the Simpson’s, biplane area-length, ellipse, and three-dimensional methods. Results were correlated using a Bland-Altman plot and linear regression models and compared by two-tailed paired-sample t tests. Reader variability was also calculated. RESULTSLeft atrial volume measurements using the biplane area-length technique showed the best correlation with Simpson’s method (r=0.92; P 0.99). CONCLUSIONThe biplane area-length method can be used for left atrial volume measurement when the Simpson’s method cannot be performed. If these two methods are not feasible, then all methods are highly reproducible and can be used, but should not be used interchangeably for follow-up studies

Preoperative evaluation of pulmonary artery morphology and pulmonary circulation in neonates with pulmonary atresia - usefulness of MR angiography in clinical routine

BACKGROUND: To explore the role of contrast-enhanced magnetic resonance angiography (CE-MRA) in clinical routine for evaluating neonates with pulmonary atresia (PA) and to describe their pulmonary artery morphology and blood supply.CE-MRA studies of 15 neonates with PA (12 female; median weight: 2900 g) were retrospectively evaluated by two radiologists in consensus. Each study was judged to be either diagnostic or non-diagnostic depending on the potential to evaluate pulmonary artery morphology and pulmonary blood supply. In those cases where surgery or conventional angiocardiography was performed results were compared. RESULTS: CE-MRA was considered diagnostic in 87%. Pulmonary artery morphology was classified as "confluent with (n = 1) and without (n = 1) main pulmonary artery", "non-confluent" (n = 6) or "absent" (n = 7). Source of pulmonary blood supply was "a persistent arterial duct" (n = 12), "a direct" (n = 22) or "indirect (n = 9) aortopulmonary collateral artery (APCA)" or "an APCA from the ascending aorta" (n = 2). In no patient were there any additional findings at surgery or conventional angiocardiography which would have changed the therapeutic or surgical approach. CONCLUSIONS: CE-MRA is a useful diagnostic tool for the preoperative evaluation of the morphology of pulmonary arteries and blood supply in neonates with PA. In most cases diagnostic cardiac catheterization can be avoided