Echocardiographic and Electrocardiographic Determinants of Atrial Cardiomyopathy Identify Patients with Atrial Fibrillation at Risk for Left Atrial Thrombogenesis.

Objective: Atrial cardiomyopathy (ACM) is associated with development of AF, left atrial (LA) thrombogenesis, and stroke. Diagnosis of ACM is feasible using both echocardiographic LA strain imaging and measurement of the amplified p-wave duration (APWD) in digital 12-lead-ECG. We sought to determine the thresholds of LA global longitudinal strain (LA-GLS) and APWD that identify patients with AF at risk for LA appendage (LAA) thrombogenesis. Methods: One hundred and twenty-eight patients with a history of AF were included. Left atrial appendage maximal flow velocity (LAA-Vel, in TEE), LA-GLS (TTE), and APWD (digital 12-lead-ECG) were measured in all patients. ROC analysis was performed for each method to determine the thresholds for LA-GLS and the APWD, enabling diagnosis of patients with LAA-thrombus. Results: Significant differences in LA-GLS were found during both rhythms (SR and AF) between the thrombus group and control group: LA-GLS in SR: 14.3 ± 7.4% vs. 24.6 ± 9.0%, p < 0.001 and in AF: 11.4 ± 4.2% vs. 16.1 ± 5.0%, p = 0.045. ROC analysis revealed a threshold of 17.45% for the entire cohort (AUC 0.82, sensitivity: 84.6%, specificity: 63.6%, Negative Predictive Value (NPV): 94.3%) with additional rhythm-specific thresholds: 19.1% in SR and 13.9% in AF, and a threshold of 165 ms for APWD (AUC 0.90, sensitivity: 88.5%, specificity: 75.5%, NPV: 96.2%) as optimal discriminators of LAA-thrombus. Moreover, both LA-GLS and APWD correlated well with the established contractile LA-parameter LAA-Vel in TEE (r = 0.39, p < 0.001 and r = −0.39, p < 0.001, respectively). Conclusion: LA-GLS and APWD are valuable diagnostic predictors of left atrial thrombogenesis in patients with AF.

Left Atrial Hypertension, Electrical Conduction Slowing, and Mechanical Dysfunction - The Pathophysiological Triad in Atrial Fibrillation-Associated Atrial Cardiomyopathy.

BACKGROUND: Atrial fibrillation (AF) is the most common arrhythmia and a significant burden for healthcare systems worldwide. Presence of relevant atrial cardiomyopathy (ACM) is related to persistent AF and increased arrhythmia recurrence rates after pulmonary vein isolation (PVI). OBJECTIVE: To investigate the association of left atrial pressure (LAP), left atrial electrical [invasive atrial activation time (IAAT) and amplified p-wave duration (aPWD)] and mechanical [left atrial emptying fraction (LA-EF) and left atrial strain (LAS)] functional parameters with the extent of ACM and their impact on arrhythmia recurrence following PVI. MATERIALS AND METHODS: Fifty patients [age 67 (IQR: 61-75) years, 78% male] undergoing their first PVI for persistent AF were prospectively included. LAP (maximum amplitude of the v-wave), digital 12-lead electrocardiogram, echocardiography and high-density endocardial contact mapping were acquired in sinus rhythm prior to PVI. Arrhythmia recurrence was assessed using 72-hour Holter electrocardiogram at 6 and 12 months post PVI. RESULTS: Relevant ACM (defined as left atrial low-voltage extent ≥2 cm2 at <0.5 mV threshold) was diagnosed in 25/50 (50%) patients. Compared to patients without ACM, patients with ACM had higher LAP [17.6 (10.6-19.5) mmHg with ACM versus 11.3 (7.9-14.0) mmHg without ACM (p = 0.009)]. The corresponding values for the electrical parameters were 166 (149-181) ms versus 139 (131-143) ms for IAAT (p < 0.0001), 163 (154-176) ms versus 148 (136-152) ms for aPWD on surface-ECG (p < 0.0001) and for the mechanical parameters 27.0 (17.5-37.0) % versus 41.0 (35.0-45.0) % for LA-EF in standard 2D-echocardiography (p < 0.0001) and 15.2 (11.0-21.2) % versus 29.4 (24.9-36.6) % for LAS during reservoir phase (p < 0.0001). Furthermore, all parameters showed a linear correlation with ACM extent (p < 0.05 for all). Receiver-operator-curve-analysis demonstrated a LAP ≥12.4 mmHg [area under the curve (AUC): 0.717, sensitivity: 72%, and specificity: 60%], a prolonged IAAT ≥143 ms (AUC: 0.899, sensitivity: 84%, and specificity: 80%), a prolonged aPWD ≥153 ms (AUC: 0.860, sensitivity: 80%, and specificity: 79%), an impaired LA-EF ≤33% (AUC: 0.869, sensitivity: 84%, and specificity: 72%), and an impaired LAS during reservoir phase ≤23% (AUC: 0.884, sensitivity: 84%, and specificity: 84%) as predictors for relevant ACM. Arrhythmia recurrence within 12 months post PVI was significantly increased in patients with relevant ACM ≥2 cm2, electrical dysfunction with prolonged IAAT ≥143 ms and mechanical dysfunction with impaired LA-EF ≤33% (66 versus 20, 50 versus 23 and 55 versus 25%, all p < 0.05). CONCLUSION: Left atrial hypertension, electrical conduction slowing and mechanical dysfunction are associated with ACM. These findings improve the understanding of ACM pathophysiology and may be suitable for risk stratification for new-onset AF, arrhythmia recurrence following PVI, and development of novel therapeutic strategies to prevent AF and its associated complications.

Non-invasive body surface electrocardiographic imaging for diagnosis of atrial cardiomyopathy.

AIMS: Atrial cardiomyopathy (ACM) is associated with new-onset atrial fibrillation, arrhythmia recurrence after pulmonary vein isolation (PVI) and increased risk for stroke. At present, diagnosis of ACM is feasible by endocardial contact mapping of left atrial (LA) low-voltage substrate (LVS) or late gadolinium-enhanced magnetic resonance imaging, but their complexity limits a widespread use. The aim of this study was to assess non-invasive body surface electrocardiographic imaging (ECGI) as a novel clinical tool for diagnosis of ACM compared with endocardial mapping. METHODS AND RESULTS: Thirty-nine consecutive patients (66 ± 9 years, 85% male) presenting for their first PVI for persistent atrial fibrillation underwent ECGI in sinus rhythm using a 252-electrode-array mapping system. Subsequently, high-density LA voltage and biatrial activation maps (mean 2090 ± 488 sites) were acquired in sinus rhythm prior to PVI. Freedom from arrhythmia recurrence was assessed within 12 months follow-up. Increased duration of total atrial conduction time (TACT) in ECGI was associated with both increased atrial activation time and extent of LA-LVS in endocardial contact mapping (r = 0.77 and r = 0.66, P < 0.0001 respectively). Atrial cardiomyopathy was found in 23 (59%) patients. A TACT value of 148 ms identified ACM with 91.3% sensitivity and 93.7% specificity. Arrhythmia recurrence occurred in 15 (38%) patients during a follow-up of 389 ± 55 days. Freedom from arrhythmia was significantly higher in patients with a TACT <148 ms compared with patients with a TACT ≥148 ms (82.4% vs. 45.5%, P = 0.019). CONCLUSION: Analysis of TACT in non-invasive ECGI allows diagnosis of patients with ACM, which is associated with a significantly increased risk for arrhythmia recurrence following PVI.

Echocardiographic diagnosis of atrial cardiomyopathy allows outcome prediction following pulmonary vein isolation.

BACKGROUND: Relevant atrial cardiomyopathy (ACM), defined as a left atrial (LA) low-voltage area ≥ 2 cm2 at 0.5 mV threshold on endocardial contact mapping, is associated with new-onset atrial fibrillation (AF), higher arrhythmia recurrence rates after pulmonary vein isolation (PVI), and an increased risk of stroke. The current study aimed to assess two non-invasive echocardiographic parameters, LA emptying fraction (EF) and LA longitudinal strain (LAS, during reservoir (LASr), conduit (LAScd) and contraction phase (LASct)) for the diagnosis of ACM and prediction of arrhythmia outcome after PVI. METHODS: We prospectively enrolled 60 consecutive, ablation-naive patients (age 66 ± 9 years, 80% males) with persistent AF. In 30 patients (derivation cohort), LA-EF and LAS cut-off values for the presence of relevant ACM (high-density endocardial contact mapping in sinus rhythm prior to PVI at 3000 ± 1249 sites) were established in sinus rhythm and tested in a validation cohort (n = 30). Arrhythmia recurrence within 12 months was documented using 72-h Holter electrocardiograms. RESULTS: An LA-EF of < 34% predicted ACM with an area under the curve (AUC) of 0.846 (sensitivity 69.2%, specificity 76.5%) similar to a LASr < 23.5% (AUC 0.878, sensitivity 92.3%, specificity 82.4%). In the validation cohort, these cut-offs established the correct diagnosis of ACM in 76% of patients (positive predictive values 87%/93% and negative predictive values 73%/75%, respectively). Arrhythmia recurrence in the entire cohort was significantly more frequent in patients with LA-EF < 34% and LASr < 23.5% (56% vs. 29% and 55% vs. 26%, both p < 0.05). CONCLUSION: The echocardiographic parameters LA-EF and LAS allow accurate, non-invasive diagnosis of ACM and prediction of arrhythmia recurrence after PVI.

Rapid improvement in left ventricular function after sinus rhythm restoration in patients with idiopathic cardiomyopathy and atrial fibrillation.

AIMS: Sinus rhythm restoration (SRR) in patients with atrial fibrillation (AF) and heart failure may improve systolic function and impact on consecutive clinical management, but time course and potential predictors of response to SRR are uncertain. METHODS AND RESULTS: We prospectively studied 50 consecutive patients who presented in heart failure with reduced ejection fraction (EF) and concomitant AF. After exclusion of valvular and coronary artery disease patients underwent electrical cardioversion. Serial echocardiography, cardiac magnetic resonance imaging (cMRI), and 24-h electrocardiograms were performed at baseline, and on Days 3 and 40 following SRR. Baseline left ventricular EF of the study population (76% male, age 69 ± 11 years) was 30 ± 7%. Sustained SRR (≥3 days) significantly improved EF (Day 3: 43 ± 7%, n = 46; Day 40: 53 ± 9%, n = 34; P < 0.001) as quantified by echocardiography. Comparable results were obtained using cMRI (baseline: 29 ± 8%; Day 3: 42 ± 9%). Three patients showed no response to SRR (EF improvement <15%). The percentage of patients meeting current criteria for implantable cardioverter-defibrillator (ICD) implantation for primary prevention dropped from 76% (n = 38) to 11% (n = 3) on Day 40 following SRR. No specific clinical or echocardiographic factor predicting improved EF after SRR could be identified. CONCLUSION: The majority of patients presenting with non-ischaemic, non-valvular heart failure with reduced EF and concomitant AF show a significant and rapid improvement in EF following SRR. An attempt at SRR and reassessment of the need for ICD implantation after 40 days may be warranted in all such patients.

Hemodynamic classification of paravalvular leakage after transcatheter aortic valve implantation compared with angiographic or echocardiographic classification for prediction of 1-year mortality.

OBJECTIVES: We sought to assess angiographic, echocardiographic and hemodynamic grading of paravalvular leakage (PVL) after transcatheter aortic valve implantation (TAVI) with respect to prediction of 1-year mortality. BACKGROUND: Meaningful criteria for the severity of PVL are needed to allow intraprocedural guidance and patient management after TAVI. METHODS: We pooled the prospective TAVI databases of 2 German centers. During TAVI, PVL was assessed angiographically and by the aortic regurgitation index (ARI). ARI was calculated as ratio of the gradient between diastolic blood pressure and left ventricular end-diastolic pressure to systolic blood pressure times hundred. In addition, we performed transthoracic echocardiography before discharge. RESULTS: A total of 723 patients undergoing TAVI with self-expandable (20.9%) or balloon-expandable (79.1%) valves were included. Grades of PVL as assessed during the procedure by angiography or ARI (below the previously defined cut-off of 25) did not show a significant association with 1-year mortality (P = 0.312 and 0.776, respectively). One-year mortality was 15.7% (39/249) in patienths with an ARI < 25 and 16.5% (71/430) in patients with an ARI ≥ 25. Echocardiographic classes of PVL at discharge showed a significant (P = 0.029) association with 1-year mortality, which was 11.5% (37/322) in patients with no/trace PVL, 18.0% (62/345) in patients with mild PVL and 23.1% (6/26) in patients with more than mild PVL. These findings prevailed after multivariable adjustment. CONCLUSIONS: ARI did not help identify PVLs that are relevant to 1-year survival. Angiographic assessment during the procedure was less predictive than echocardiographic assessment before discharge.

Inconsistent grading of aortic valve stenosis by current guidelines: haemodynamic studies in patients with apparently normal left ventricular function.

BACKGROUND: On echocardiography approximately one-third of patients with severe aortic valve stenosis based on aortic valve area (AVA<1.0 cm(2)) demonstrate a non-severe mean pressure gradient (DeltaPm; < or =40 mm Hg) despite apparently normal left ventricular function. It has been suggested that inconsistent echocardiographic grading may be due to 'paradoxical' low stroke volume. However, the correct echocardiographic assessment of stroke volume hinges on the often problematic measurement of the left ventricular outflow tract (LVOT) diameter. OBJECTIVE: To investigate whether inconsistent grading and reduced stroke volume persist when the quantification of aortic valve stenosis is based on cardiac catheterisation which is independent of LVOT measurements. METHODS AND RESULTS: 333 consecutive patients underwent cardiac catheterisation within 30 days after their index echocardiography showing an AVA < or =2 cm(2) and shortening fraction > or =30%. On invasive testing 85 patients (26%) demonstrated inconsistent (AVA<1 cm(2) and DeltaPm< or =40 mm Hg) and 153 (46%) consistent grading (AVA<1 cm(2) and DeltaPm>40 mm Hg) with the remainder (28%) presenting with a calculated AVA> or =1 cm(2). Inconsistently graded patients were older (71 vs 67 years, p<0.006) with no differences in sex or body surface area between groups. Stroke volume and stroke volume index were significantly lower in inconsistently graded patients (63+/-14 vs 73+/-18 ml and 35+/-7 vs 39+/-7 ml/m(2), respectively, both p<0.001). However, 41/85 (48%) of inconsistently graded patients had a normal stroke volume index >35 ml/m(2). CONCLUSION: In the framework of current guidelines inconsistent grading of aortic valve stenosis is common, extends to cardiac catheterisation and is only partially explained by low stroke volume despite apparently normal left ventricular systolic function.

Pressure-guided cryoballoon isolation of the pulmonary veins for the treatment of paroxysmal atrial fibrillation.

BACKGROUND: Pulmonary vein (PV) isolation using a balloon-mounted cryoablation system is a new technology for the percutaneous treatment of atrial fibrillation (AF). Complete PV occlusion during balloon ablation has been shown to predict successful electrical isolation. The aim of this study was to correlate mechanical PV occlusion with changes in a pressure curve recorded at the distal tip of the cryoballoon catheter. METHODS AND RESULTS: We analyzed 51 PVs in 12 patients (61 +/- 6 years old) with paroxysmal AF. At first, PV occlusion via the cryoballoon was documented by changes in the pressure curve. Once the PV is occluded, the pressure curve registered in the vein converts from a left atrial pressure curve to a pulmonary artery pressure curve: the PV wedge curve. Occlusion was then confirmed by transesophageal echocardiography (TEE). Following 2 cryoablation applications, electrical PV isolation was assessed with a circumferential mapping catheter. Under the exclusive guidance of changes in the pressure curve at the tip of the cryoballoon, mechanical occlusion confirmed by TEE was achieved in 47 of 51 PVs (92%). Three PVs required further TEE guidance to achieve occlusion. All 50 occluded veins were electrically isolated after cryoablation. One right inferior vein, which could not be occluded with the balloon, displayed conduction post cryoablation and was isolated by focal ablation. CONCLUSIONS: Occlusion and electrical isolation of PVs during cryoballoon ablation can be predicted by the appearance of a PV wedge curve at the tip of the catheter. This new straightforward parameter may facilitate the procedure.

Cryoballoon pulmonary vein isolation guided by transesophageal echocardiography: novel aspects on an emerging ablation technique.

BACKGROUND: Pulmonary vein (PV) isolation using a balloon-mounted cryoablation system is a new technology for the percutaneous treatment of atrial fibrillation (AF). Transesophageal echocardiography (TEE) allows real-time visualization of cryoballoon positioning and successful vein occlusion via color Doppler. We hypothesized that PV mechanical occlusion monitored with TEE could predict effective electrical isolation. METHODS: We studied 124 PVs in 30 patients. Under continuous TEE assessment, a cryoballoon was placed in the antrum of each PV aiming for complete PV occlusion as documented by color Doppler. At the end of the procedure, PV electrical isolation was evaluated using a circumferential mapping catheter. RESULTS: Of the 124 PVs studied, 123 (99.2%) could be visualized by TEE: the antrum was completely visualized in 80 of them (64.5%), partially in 36 (29.0%), and only disappearance of proximal flow could be observed in the remaining 7 PVs (5.7%). Vein occlusion could be achieved in 111 of the 123 (90.2%) visualized PVs. Postinterventional mapping demonstrated electrical isolation in 109 of 111 occluded PVs (positive predictive value 98.2%) and only in 1 of 12 nonoccluded PVs (negative predictive value 91.7%, P < 0.001). After a mean follow-up of 7.4 +/- 3.7 months, 73.3% of patients remained in sinus rhythm without antiarrhythmic drugs. CONCLUSION: Color Doppler documented PV occlusion during cryoballoon ablation can predict effective electrical isolation.

Inconsistencies of echocardiographic criteria for the grading of aortic valve stenosis.

AIM: The present study tests the consistency of echocardiographic criteria for the grading of aortic valve stenosis. METHODS AND RESULTS: Current guidelines/recommendations define severe stenosis as an aortic valve area (AVA) <1 cm2 (or <0.6 cm2 adjusted for body surface area), mean pressure gradient (DeltaPm) >40 mmHg, or peak flow velocity (Vmax) >4 m/s. We tested the consistency of the three criteria for the grading of aortic valve stenosis in 3483 echocardiography studies performed in 2427 patients with normal left ventricular (LV) systolic function and a calculated AVA of < or =2 cm2. We calculated curve fits for the relationship between AVA and DeltaPm using the Gorlin equation and between AVA and Vmax based on the continuity equation for our study population. An AVA of 1.0 cm2 correlated to a DeltaPm of 21 mmHg and a Vmax of 3.3 m/s. Conversely, a DeltaPm of 40 mmHg corresponds to an AVA of 0.75 cm2 and a Vmax of 4.0 m/s to an AVA of 0.82 cm2. Consequently, severe stenosis was diagnosed in 69% of patients based on AVA, 45% on Vmax, and 40% on DeltaPm. Stroke volume was lower in inconsistently graded patients (65 +/- 11 mL vs. consistently graded: 70 +/- 14 mL, P < 0.001). CONCLUSION: The criteria for the grading of aortic stenosis are inconsistent in patients with normal systolic LV function. On the basis of AVA, a higher proportion of patients is classified as having severe aortic valve stenosis compared with mean pressure gradient and peak flow velocity. Discrepant grading in these patients may be partly due to reduced stroke volume.