Left atrial total emptying fraction measured by cardiovascular magnetic resonance imaging predicts low-voltage areas detected during electroanatomical mapping.

AIMS: Low-voltage areas (LVAs) found during left atrial (LA) electroanatomical mapping are increasingly targeted by radiofrequency catheter ablation (RFCA) on top of pulmonary vein isolation to improve arrhythmia-free survival in patients with atrial fibrillation (AF). However, pre-procedural prediction of LVAs remains challenging. The purpose of the present study was to describe the association between parameters of LA function and dimensions, respectively, derived from pre-procedural cardiovascular magnetic resonance (CMR) imaging, and the presence of LVAs on LA voltage mapping. METHODS AND RESULTS: Patients who underwent first-time RFCA for paroxysmal or persistent AF and who were in stable sinus rhythm during pre-procedural CMR imaging were included in this study. Cardiovascular magnetic resonance-derived parameters of LA function and dimensions were calculated. Low-voltage areas were defined as areas with bipolar voltage amplitudes of ≤0.5 mV on electroanatomical mapping. In total, 259 consecutive patients were included in this analysis. Low-voltage areas were found in 25 of 259 patients (9.7%). Compared with those without LVAs, patients with LVAs were significantly older, were more likely to be female, had a higher CHA2DS2-VASc score, had larger LA volumes, and had a lower LA total emptying fraction (TEF). In multivariate analysis, only LA TEF [odds ratio (OR) 0.885, 95% confidence interval (CI) 0.846-0.926, P < 0.001] and the CHA2DS2-VASc score (OR 1.507, 95% CI 1.115-2.038, P = 0.008) remained independently associated with the presence of LVAs. CONCLUSION: Left atrial TEF and the CHA2DS2-VASc score were independently associated with the presence of LVAs found during LA electroanatomical mapping. These findings may help to improve pre-procedural prediction of pro-arrhythmogenic LVAs and to improve peri-procedural patient management.

Abnormal pattern of left atrial activation and asynchronous conduction predicted the occurrence of new atrial fibrillation: evidences for Bachmann's bundle block in atrial fibrillation pathophysiology.

AIMS: Evidences suggest that recurrent atrial fibrillation (AF) is associated with left atrial (LA) remodelling. The goal of this study is to establish a method for assessment of LA remodelling and find predictors for the development of AF. METHODS AND RESULTS: This prospective study included patients without a history of AF who were evaluated using pulsed-wave tissue Doppler imaging (PW-TDI). P-wave onset to A'-wave (PA' interval) was measured at the septal, lateral, anterior, and inferior mitral annulus. Abnormal LA activation pattern was defined as an upward LA activation over the coronary sinus and delayed activation anterior. Left atrial asynchrony was measured as (i) the difference between the septal and lateral PA' interval (DLS) and (ii) the standard deviation of all four PA' intervals (SD4-PA'). The follow-up for AF recurrence (AF+) was based on symptoms and 7-day Holter electrocardiograms. Ninety-eight patients (mean age 58 ± 15 years, 47% female) were included. During a follow-up of 28 ± 9 months, AF was documented in 10%. More pronounced LA asynchrony was observed in AF+ group: DLS (AF+) 39 ± 16 vs. DLS (AF-) 20 ± 11 ms; P < 0.001, and SD4-PA' (AF+) 18.6 ± 6.4 vs. SD4-PA' (AF-) 11.7 ± 4.2 ms; P < 0.001. Abnormal LA activation was frequently observed in AF+ patients: 60% vs. 27%; P = 0.033. Electrocardiogram sign of Bachmann's bundle block (BBB) was associated with prolongation of SD4-PA': SD4-PA' (BBB+) vs. SD4-PA' (BBB-) = 18 ± 6 vs. 13 ± 4.5 ms; P = 0.007. CONCLUSIONS: More pronounced LA asynchrony and abnormal LA activation pattern were associated with new-onset AF.

Cardiovascular magnetic resonance imaging in patients with cardiac implantable electronic devices: best practice and real-world experience.

AIMS: Cardiovascular magnetic resonance (CMR) imaging has long been a contraindication for patients with a cardiac implantable electronic device (CIED). Recent studies support the feasibility and safety for non-thoracic magnetic resonance imaging, but data for CMR are sparse. The aim of the current study was to determine the safety in patients with magnetic resonance (MR)-conditional or non-MR-conditional CIED and to develop a best practice approach. METHODS AND RESULTS: All patients with a CIED undergoing CMR imaging (1.5 T) between April 2014 and April 2017 were included in the study. Devices were programmed according to the standardized protocol directly before and after the CMR examination. Follow-up interrogation was performed 6 months after CMR examination. Results were compared with a large, reference cohort of CIED patients not undergoing any MR examination. A total of 200 consecutive patients with a CIED (non-MR-conditional, n = 103) were included in the study. Directly after CMR imaging, one device failure (0.5%, battery status = end of service) was noted necessitating premature generator replacement. In three patients (2%) of pacemaker/implantable cardioverter-defibrillator (ICD) carriers a sustained ventricular tachycardia (VT) occurred during CMR imaging. Ten ICD showed a decrease in battery capacity immediately after CMR. Overall, the reference cohort showed comparable changes of CIED function during follow-up. CONCLUSION: With adherence to a standardized protocol and established exclusion criteria CMR imaging could safely be performed in patients with a CIED. The potential risks of device malfunction necessitate the presence of a device trained individual during the entire CMR examination. If there is a history of VT storm the attendance of an experienced cardiologist, should be mandatory.

J wave pattern in unexplained syncope.

J wave pattern (JWP), characterized by J-point elevation in the anterolateral or inferior leads of the 12-lead electrocardiogram, has been associated with increased risk for idiopathic ventricular fibrillation and mortality. However, its prevalence in syncope of different etiologies is unknown and was evaluated in this study. The study sample comprised 170 consecutive patients with vasovagal syncope or syncope that remained unexplained after complete work-up. JWP in inferior leads and with a horizontal/descending ST-segment is more frequently found in subjects with unexplained syncope than in subjects with vasovagal syncope. This finding may be linked with worse prognosis of unexplained syncope.

Optimal timing of contrast-enhanced three-dimensional magnetic resonance left atrial angiography before pulmonary vein ablation.

BACKGROUND: To achieve high image quality of cardiovascular magnetic resonance (CMR) pulmonary vein (PV) angiography prior catheter ablation in patients with atrial fibrillation, optimal timing of the angiographic sequence during contrast agent passage is important. The present study identified influential cardiovascular parameters for prediction of contrast agent travel time. METHODS: One hundred six consecutive patients underwent a CMR examination including three-dimensional (3D) contrast-enhanced PV angiography with real-time bolus tracking prior to catheter ablation. Correct scan timing was characterized by relative signal enhancement measurements in the pulmonary artery, left atrium (LA), and ascending aorta. Furthermore, left- and right-ventricular function, left- and right-atrial dimensions, presence of mitral or tricuspid insufficiencies, and main pulmonary artery diameter were determined. RESULTS: The highest relative signal enhancement in LA demonstrated optimal scan timing. Contrast agent travel time showed wide variability (range: 12-42 s; mean: 18 ± 4 s). On univariate analysis, most cardiovascular parameters correlated with contrast agent travel time while on multivariate analysis left- and right-ventricular function remained the only independent predictors, but overall a poor fit to the data (adjusted R2, 27.5%) was found. CONCLUSIONS: Contrast agent travel time was mainly influenced by left- and right-ventricular function but prediction models poorly fitted the data. Thus, 3D PV angiography prior to PV ablation procedures necessitates real-time assessment, with visual determination of individual contrast agent passage time to ensure consistently high CMR image quality.

Quantification of regurgitation in mitral valve prolapse with automated real time echocardiographic 3D proximal isovelocity surface area: multimodality consistency and role of eccentricity index.

Three-dimensional transthoracic echocardiography (3D-TTE) provides a semi-automated proximal isovelocity surface area method (3D-PISA) to obtain quantitative parameters. Data assessing regurgitation severity in mitral valve prolapse (MVP) are scarce, so we assessed the 3D-PISA method compared with 2D-PISA and cardiovascular magnetic resonance (CMR) and the role of an eccentricity index. We evaluated the 3D-PISA method for assessing MR in 54 patients with MVP (57 ± 14 years; 42 men; 12 mild/mild-moderate; 12 moderate-severe; and 30 severe MR). Role of an asymmetric (i.e. eccentricity index ≥ 1.25) flow convergence region (FCR) and inter-modality consistency were then assessed. 3D-PISA derived regurgitant volume (RVol) showed a good correlation with 2D-PISA and CMR derived parameters (r = 0.86 and r = 0.81, respectively). The small mean differences with 2D-PISA derived RVol did not reach statistical significance in overall population (5.7 ± 23 ml, 95% CI - 0.6 to 12; p = 0.08) but differed in those with asymmetric 3D-FCR (n = 21; 2D-PISA: 72 ± 36 ml vs. 3D-PISA: 93 ± 47 ml; p = 0.001). RVol mean values were higher using PISA methods (CMR 57 ± 33 ml; 2D-PISA 73 ± 39 ml; and 3D-PISA 79 ± 45 ml) and an overestimation was observed when CMR was used as reference (2D-PISA vs. CMR: mean difference: 15.8 ml [95% CI 10-22, p < 0.001]; and 3D-PISA vs. CMR: 21.5 ml [95% CI 14-29, p < 0.001]). Intra- and inter-observer reliability was excellent (ICC 0.91-0.99), but with numerically lower coefficient of variation for 3D-PISA (8%-10% vs. 2D-PISA: 12%-16%). 3D-PISA method for assessing regurgitation in MVP may enable analogous evaluation compared to standard 2D-PISA, but with overestimation in case of asymmetric FCR or when CMR is used as reference method.

Left atrial activation and asymmetric anatomical remodeling in patients with atrial fibrillation: The relation between anatomy and function.

BACKGROUND: Identifying patients with advanced left atrial (LA) remodeling before catheter ablation (CA) of atrial fibrillation (AF) is crucial. HYPOTHESIS: This study aimed to identify echocardiographic parameters associated with changes in anatomy and conduction properties of the left atrium (LA). METHODS: We examined 75 AF patients prior to CA and measured the intervals from the P-wave-onset to four mitral annulus sites by pulsed-wave tissue Doppler imaging (PW-TDI). Patients were grouped to an upward U-pattern (delayed anterior activation) and a downward D-pattern (earliest LA activation anterior). CT-data were used to measure the LA volume (LAV). LAV was divided into anterior- (LA-A) and posterior-parts by a plane, parallel to the posterior wall and between the veins and the appendage, to calculate the asymmetry index (ASI = LA-A/LAV). RESULTS: Patients with U-pattern (n = 66) had a higher ASI (65 ± 6 vs. 61 ± 3%, p = .014), older age (61 ± 11 vs. 51 ± 11 years, p = .03) and more diastolic dysfunction (71 vs. 22%, p = .008) Multivariate regression showed that age (OR 1.1 per year, CI 1.007-1.199) and diastolic dysfunction (OR 6.36, CI 1.132-35.7, p = .036) were independent predictors of the U-pattern. Diastolic dysfunction (B 4.49, CI 1.61-7.37, p = .003) was the only independent predictor of ASI in linear regression analysis. CONCLUSION: AF patients with a U-pattern have an increased LA asymmetry. Diastolic dysfunction is a common cause of this LA activation and remodeling. Therefore, detection of a U-pattern signifies patients with advanced AF and may facilitate selection for an appropriate ablation strategy.

Grading of aortic regurgitation by cardiovascular magnetic resonance and pulsed Doppler of the left subclavian artery: harmonizing grading scales between imaging modalities.

Transthoracic echocardiography (TTE) and cardiac magnetic resonance (CMR) are current standard for assessing aortic regurgitation (AR). Regurgitant fraction (RF) can also be estimated by Doppler examination of the left subclavian artery (LSA-Doppler). However, a comparison of AR grading scales using these methods and a TTE multiparametric approach as reference is lacking. We evaluated the severity of AR in 73 patients (58 ± 15 years; 57 men), with a wide spectrum of AR of the native valve. Using a recommended TTE multiparametric approach the AR was divided in none/trace (n = 12), mild (n = 23), moderate (n = 12), and severe (n = 26). RF was evaluated by LSA-Doppler (ratio between diastolic and systolic velocity-time integrals) and by CMR phase-contrast imaging (performed in the aorta 1 cm above the aortic valve); the grading scales were then calculated. There were a good correlation between all methods, but mean RF values were greater with TTE compared with LSA-Doppler and CMR (39 ± 16% vs. 35 ± 18% vs. 32 ± 20%, respectively; p < 0.037). Mean differences in RF values between methods were significant in the groups with mild and moderate AR. Grading scales that best defined the TTE derived AR severity using CMR were: mild, < 21%; moderate, 22 to 41%; and severe, > 42%; and using LSA-Doppler: mild, < 29%; moderate, 30 to 44%; and severe, > 45%. RF values for AR grading using TTE, LSA-Doppler and CMR correlate well but differ in groups with mild and moderate AR when using a recognized multiparametric echocardiographic approach. Clinical prospective studies should validate these proposed modality adjusted grading scales.

Quantification of Aortic Valve Regurgitation by Pulsed Doppler Examination of the Left Subclavian Artery Velocity Contour: A Validation Study with Cardiovascular Magnetic Resonance Imaging.

BACKGROUND: Reflux of the aortic regurgitation (AR) causes an increased diastolic reverse flow in the aorta and its branching vessels. We aimed to evaluate the feasibility and accuracy of Doppler measurements in the left subclavian artery (LSA) for quantification of AR in a cardiovascular magnetic resonance imaging (CMR) validation study. METHODS: Systolic and diastolic flow profiles of the LSA (subclavicular approach) were evaluated prospectively by use of pulsed wave Doppler in 59 patients (55.5 ± 15 years; 44 men), 47 with a wide spectrum of AR and 12 as control group. Using CMR phase-contrast sequences (performed 1 cm above the aortic valve), the AR was divided into three groups: mild, regurgitant fraction (RF) < 20% (n = 17); moderate, RF 20%-40% (n = 10); and severe, RF > 40% (n = 20). The LSA Doppler-derived RF was calculated as the ratio between diastolic and systolic velocity-time integrals (VTI). RESULTS: Quality LSA Doppler signal could be obtained in all cases. Patients with CMR severe AR had higher values of LSA Doppler-derived RF (51% ± 9% vs 36% ± 11% vs 16% ± 8%; P < .0001). LSA Doppler showed a good correlation with CMR, with a sensitivity of 95%, specificity of 89%, and diagnostic accuracy for severe AR of 91.5%. Finally, Bland-Altman plots showed agreement in the group with moderate to severe AR (mean bias = -2.2% ± 8%, 95% CI, -17.7 to 13.3; P = .145) but differed in mild AR. CONCLUSIONS: Measurements of the RF for quantification of AR using LSA Doppler are comparable to those of CMR, highlighting the potential role of LSA Doppler as an adjunctive technique to assess the severity of AR.

Patterns of left atrial activation and evaluation of atrial dyssynchrony in patients with atrial fibrillation and normal controls: Factors beyond the left atrial dimensions.

BACKGROUND: Left atrial (LA) remodeling causing slower and asynchronous conduction is crucial for the maintenance of atrial fibrillation (AF). OBJECTIVE: We propose a simple and quick method to evaluate the LA asynchrony. METHODS: One hundred thirty patients with AF (AF group) and 70 patients without a history of AF (controls) were examined prospectively using pulsed-wave tissue Doppler imaging. The time intervals from the onset of the P wave to the onset of the A' wave (P-A' intervals) were measured at 4 sites at the mitral annulus: septal, lateral, anterior, and posterior. To assess the LA asynchrony, the differences between the longest and the shortest P-A' interval as well as the standard deviation of all 4 P-A' intervals were calculated. RESULTS: Both groups were matched for the baseline characteristics. The AF group had longer differences between the longest and the shortest P-A' than did controls (37 ± 16 ms vs 28 ± 13 ms; P = .0001). The standard deviation of all 4 P-A' intervals was also higher in the AF group (17 ± 7 ms vs 13 ± 5 ms; P = .0001). Furthermore, distinct patterns of LA activation were observed with most patients with AF showing upward LA activation (86.5%) whereas normal controls were showing downward LA activation (65.5%). Receiver operating characteristic analysis revealed that P-A' anterior successfully discriminated patients with AF from controls (area under the curve 0.85; P < .0001). Furthermore, P-A' anterior > 55 ms discriminated between patients with AF and controls with a sensitivity of 85% a specificity of 81%, a positive predictive value of 0.898, and a negative predictive value of 0.707. CONCLUSION: Patients with AF showed greater LA asynchrony in pulsed-wave tissue Doppler imaging, upward LA activation, and a prolonged activation time at the anterior mitral annulus. Prolongation of P-A' anterior discriminated between patients with AF and controls with high sensitivity and specificity.

Usefulness of dronedarone in patients with atrial arrhythmias.

Dronedarone is a novel class III antiarrhythmic drug with moderate efficacy in preventing atrial arrhythmias. However, only few data from the real-world use of dronedarone with limited electrocardiographic monitoring are available. The investigators report the incidence, timing, and reasons for discontinuation of dronedarone; maintenance of sinus rhythm; and atrial arrhythmia recurrence patterns in 120 consecutive patients with atrial fibrillation (AF; n = 91) or non-isthmus-dependent atrial flutter (n = 29) treated with dronedarone (400 mg twice daily). Rhythm control was assessed with serial 7-day Holter electrocardiography after 4 weeks and after 6 to 9 months. After drug initiation, dronedarone was discontinued in 19 patients (16%) because of inefficacy (n = 7 [6%]) or adverse events (n = 12 [10%]). At 4 weeks, 44 patients (37%) had stopped taking dronedarone because of inefficacy (n = 27 [23%]) or adverse events (n = 17 [14%]). After 6 to 9 months, 25 patients (21%) had discontinued dronedarone because of clinical inefficacy (n = 16 [13%]) or adverse events (n = 9 [8%]). Overall, dronedarone was still used after 6 to 9 months in 32 patients (27%). Maintenance of sinus rhythm was achieved in 40 patients (33%) after 4 weeks and in 24 patients (20%) after 6 to 9 months. Reversal from persistent to paroxysmal arrhythmias was observed in 23 patients, (29%) whereas progression from paroxysmal to persistent arrhythmias occurred in 6 patients (15%). Conversion from AF to non-isthmus-dependent atrial flutter was noted in 10 patients (13%). In conclusion, dronedarone is associated with frequent adverse events and moderate antiarrhythmic efficacy requiring discontinuation in most patients within the first 9 months of use, and there is a prevalent reversal from persistent to paroxysmal but also from paroxysmal to persistent atrial arrhythmias and from AF to non-isthmus-dependent atrial flutter.