Left Ventricular Inflow Velocity Pattern in Patients With Symptomatic Premature Ventricular Contraction.

BACKGROUND: Because premature ventricular contractions (PVCs) are one of the most common arrhythmias, but with unclear causative mechanisms, we studied the hemodynamic features that can cause symptomatic PVCs.Methods and Results:We studied 109 patients (48 males, age 60±19 years) with frequent monomorphic PVCs and no structural heart disease. The left ventricular inflow diastolic filling velocity was recorded by transthoracic echocardiography (TTE) at the time of PVCs in all patients. We assessed the PVC E wave flow (E wave velocity×duration at PVC). A total of 38 patients (35%) had PVC-related symptoms (19 palpitations, 12 pulse deficit, 6 shortness of breath, 6 malaise, 1 syncope). These patients showed reduced PVC E wave flow (9.3±6.0 vs. 14.6±6.5 cm, P<0.0001), and reduced PVC stroke volume (20.5±10.8 vs. 29.9±17.2 mL, P=0.0030). In the multivariate analysis, only reduced PVC E wave flow was independently associated with PVC-related symptoms (P=0.00349, odds ratio: 1.134029, each 1.0 cm increase in PVC E wave flow, 95% confidence interval: 1.040726-1.247544). CONCLUSIONS: Decreased E wave flow at the time of PVC was independently related with PVC-related symptoms in patients with PVCs. The LV contraction at the time of inadequate filling might be a cause of PVC-related symptoms.

The association between left atrial stiffness and low-voltage areas of left atrium in patients with atrial fibrillation.

The low-voltage areas of left atrium (LA-LVA) have recently been of significant focus. However, very few studies have focused on the association between LA function and LA-LVA, and the mechanism of appearance of LA-LVA remains unclear. We investigated the marker for the existence of LA-LVA using automated 3-D mapping system. We studied 92 patients (75 males, 68 ± 9 years, 47 non-paroxysmal AF) who received CA for AF and 40 control patients without AF. Echocardiography was performed before the CA, and high-density voltage mapping during sinus rhythm after pulmonary isolation was performed in AF patients. LA-LVA was defined as < 0.5 mV, and LA stiffness index (LASI) was defined as the ratio of E/e' to LA peak strain. LA-LVA (LVA burden > 10%) was detected in 19/92 AF patients (21%). Patients with LA-LVA were associated with higher LASI (1.64 ± 1.70 vs. 0.61 ± 0.46, p < 0.0001), larger LA volume, non-paroxysmal AF, higher brain natriuretic peptide, structural heart disease, and older age. On multivariate analysis, LASI, LA volume, and age were independently associated with the existence of LA-LVA. Of these markers, the highest area under curve was obtained with LASI. The rate of high LASI (≥ 0.552) was highest in AF patients with LA-LVA. Moreover, the existence of LVA in anterior LA wall was associated with higher LASI. High LA stiffness index was associated with the presence of LA-LVA. The LA-LVA might be attributed to LA functional remodeling rather than LA anatomical remodeling.

Predictors of Left Atrial Thrombi and Spontaneous Echocardiographic Contrast in the Acute Phase After Cardioembolic Stroke in Patients With Atrial Fibrillation.

INTRODUCTION: The underlying mechanism of the residual left atrial thrombus (LAT)/spontaneous echo contrast (SEC) after the onset of cardioembolic stroke (CES) is unknown. This study aims to investigate the utility of CHADS2 and CHA2DS2-VASc scores for predicting LAT/SEC, and to investigate the risk factors of residual LAT/SEC after CES onset. METHODS: This retrospective study included 124 patients who were admitted with the acute phase of CES at our center. The clinical, echocardiographic variables, the CHADS2/CHA2DS2-VASc scores, and National Institutes of Health Stroke Scale score were retrospectively assessed on admission. RESULTS: Of 124 patients, LAT or SEC was detected in 39 patients (31.5%, 17 LAT and 38 SEC). Univariate analysis showed that the LAT/SEC group had a higher prevalence of nonparoxysmal atrial fibrillation (AF), left ventricular (LV) hypertrophy, hypertension, the rate of anticoagulation before admission, higher National Institutes of Health Stroke Scale score, larger left atrial diameter, and elevated E wave. In contrast, the CHADS2 and CHA2DS2-VASc scores were not associated with LAT/SEC. LAT/SEC was associated with nonparoxysmal AF and LV hypertrophy on multivariate analysis. Moreover, all patients were divided into 4 groups based on the combination between non-paroxysmal AF and LV hypertrophy. The rate of LAT/SEC was the highest (87.5%) in patients with nonparoxysmal AF and LV hypertrophy. CONCLUSIONS: Nonparoxysmal atrial fibrillation and left ventricular hypertrophy were associated with residual left atrial thrombus/spontaneous echo contrast in the acute phase after cardioembolic stroke that was independent of the CHADS2 and CHA2DS2-VASc scores.

Predictors of left atrial appendage stunning after electrical cardioversion in patients with atrial fibrillation.

The transient left atrial appendage (LAA) dysfunction after electrical cardioversion (CV), which is called as LAA-stunning, was found to be an important etiology of thrombus formation. The aim of the present study was to investigate the risk factors of LAA-stunning. This study included 134 patients who underwent catheter ablation for non-paroxysmal, non-valvular, and symptomatic atrial fibrillation (AF). Internal-CV was performed, and LAA emptying fraction (LAA-EF) was assessed using LAA-angiogram before and just after CV. LAA-stunning (defined as 10% reduction of LAA-EF after CV) was observed in 45/134 patients (34%). Patients in LAA-stunning group had longer duration of AF prior to CV, higher brain natriuretic peptide (BNP), higher prevalence of patients taking calcium blocker, larger left atrial (LA) diameter, elevated E wave, and larger LA volume than those in non LAA-stunning group. Multivariate analysis showed that longer duration of AF prior to CV (p = 0.015, OR 1.033 for 1 month extend, 95% CI 1.006-1.073) and elevated BNP (p = 0.038, OR 1.041 for each 10 pg/mL increase, 95% CI 1.001-1.009) were associated with LAA-stunning. In addition, all patients were divided into four groups based on the combination between duration of AF prior to CV and BNP; group 1 (low BNP/short-lasting AF), group 2 (high BNP/short-lasting AF), group 3 (low BNP/long-lasting AF), and group 4 (high BNP/long-lasting AF). The rate of LAA-stunning was the highest in the group 4 (55.6%). Elevated BNP and long duration of AF were associated with LAA stunning after electrical cardioversion.

A novel protocol for initial heparin administration during catheter ablation for atrial fibrillation in patients taking direct oral anticoagulants.

Thromboembolism and bleeding complications remain a major limitation of the catheter ablation (CA) for atrial fibrillation (AF). This study aimed to evaluate the association between achieving target activated clotting time (ACT) and clinical factors, and to develop an appropriate protocol for early achievement of target ACT in patients with direct oral anticoagulants (DOACs). At the initiation cohort, 190 patients (127 males, age 68 ± 9) taking DOACs who underwent CA for AF were studied. All patients underwent transthoracic echocardiography/transesophageal echocardiography/blood sampling before the CA. The ACTs were measured before heparin administration (pre-ACT) and in 30 min (30-min ACT) after initial heparin administration (100 U/kg +3000 U). At the validation cohort, the indicator obtained from the first study was reassessed in the subsequent 138 patients (94 males, age 68 ± 10). At the initiation cohort, 30-min ACT reached the target ACT in 79/190 patients (42%). Univariate analysis showed that longer pre-ACT, elevated aPTT, higher PT-INR, antiplatelet medication, and dabigatran were associated with achieving the target 30-min ACT. On multivariate analysis, only longer pre-ACT was independently associated with achieving the target 30-min ACT (P = 0.0396, the optimal cutoff value; 130 s). As a novel protocol, we added 2000 U of initial heparin dose (total 100 U/kg +5000 U) in patients with low pre-ACT (< 130); then, the achievement rate to target 30-min ACT improved from 41.6 to 80.5% without increasing bleeding complications. Our novel protocol of initial heparin administration based on pre-ACT is useful for an appropriate systemic anticoagulation in patients taking DOACs during the CA for AF.

Left atrial pressure pattern without a-wave in sinus rhythm after cardioversion affects the outcomes after catheter ablation for atrial fibrillation.

The a-wave in left atrial pressure (LAP) is often not observed after cardioversion (CV). We hypothesized that repeated atrial fibrillation (AF) occurs in patients who do not show a-wave pattern after CV. We investigated the impact of "LAP pattern without a-wave" on the outcome after catheter ablation (CA) for AF. We studied 100 patients (64 males, age 66 ± 8 years, 42 with non-paroxysmal AF) who underwent CA for AF. Sustained- or induced-AF were terminated with internal CV, and LAP was measured during sinus rhythm (SR) after CV. LAP pattern without a-wave was defined as absence of a-wave (the "a-wave" was defined as a protruding part by 0.2 mmHg or more from the baseline) in LAP wave form. AF was terminated with CV in all patients. Recurrent AF was detected in 35/100 (35%) during the follow-up period (13.1 ± 7.8 month). Univariate analysis revealed higher prevalence of LAP pattern without a-wave (71 vs. 17%, P < 0.0001), larger left atrial volume, elevated E wave, and decreased deceleration time as significant variables. On multivariate analysis, LAP pattern without a-wave was only independently associated with recurrent AF (P = 0.0014, OR 9.865, 95% CI 2.327-54.861). Moreover, patients with LAP pattern without a-wave had a higher risk of recurrent AF than patients with a-wave (25/36 patients, 69 vs. 10/64 patients, 16%, log-rank P < 0.0001). Left atrial pressure pattern without a-wave in sinus rhythm after cardioversion could predict recurrence after catheter ablation for AF.

Interatrial septal motion as a novel index to predict left atrial pressure.

We investigated whether the interatrial septal (IAS) motion of each heartbeat which is observed by transesophageal echocardiography reflects left atrial pressure (LAP) in patients with atrial fibrillation (AF). We studied 100 patients (70 males, age 67 ± 9 years) who underwent catheter ablation for AF. The amplitude of IAS motion was measured using M-mode and averaged for five cardiac cycles. Left and right atrial pressures, the left to right atrial pressure gradient were directly measured during the catheter ablation. In patients with sinus rhythm during measurement, elevated mean LAP, larger maximum left to right atrial pressure gradient, and greater left atrial emptying fraction were associated with IAS motion. The optimal cut-off value of the IAS motion for predicting high LAP (mean LAP > 15 mmHg) was 8.5 mm (sensitivity 100%, specificity 70.1%) in patients with sinus rhythm during pressure measurement. In addition, all patients were divided into 6 groups based on rhythm during measurement and cutoff value of IAS motion. In patients with sinus rhythm during measurement, low IAS motion group had a highest prevalence of elevated LAP compared with high IAS motion group (64 vs. 0%, P < 0.0001). The amplitude of interatrial septal motion during sinus rhythm reflects left atrial pressure in patients with atrial fibrillation. Interatrial septal motion could be a new index to predict elevated left atrial pressure.

Left atrial ejection force predicts the outcome after catheter ablation for paroxysmal atrial fibrillation.

INTRODUCTION: Left atrium (LA) systolic dysfunction is observed in the early stages of atrial fibrillation (AF) prior to LA anatomical change. We investigated whether LA systolic dysfunction predicts recurrent AF after catheter ablation (CA) in patients with paroxysmal AF. METHODS AND RESULTS: We studied 106 patients who underwent CA for paroxysmal AF. LA systolic function was assessed with the LA emptying volume = Maximum LA volume (LAVmax ) - Minimum LA volume (LAVmin ), LA emptying fraction = [(LAVmax - LAVmin )/LAVmax ] × 100, and LA ejection force calculated with Manning's method [LA ejection force = (0.5 × ρ × mitral valve area × A2 )], where ρ is the blood density and A is the late-diastolic mitral inflow velocity. Recurrent AF was detected in 35/106 (33%) during 14.6 ± 9.1 months. Univariate analysis revealed reduced LA ejection force, decreased LA emptying fraction, larger LA diameter, and elevated brain natriuretic peptide as significant variables. On multivariate analysis, reduced LA ejection force and larger LA diameter were independently associated with recurrent AF. Moreover, patients with reduced LA ejection force and larger LA diameter had a higher risk of recurrent AF than preserved LA ejection force (log-rank P = 0.0004). CONCLUSIONS: Reduced LA ejection force and larger LA diameter were associated with poor outcome after CA for paroxysmal AF, and could be a new index to predict recurrent AF.

The Impact of Transforming Growth Factor-ß1 Level on Outcome After Catheter Ablation in Patients With Atrial Fibrillation.

INTRODUCTION: Transforming growth factor-ß1 (TGF-ß1 ) is an important factor that induces atrial fibrosis and atrial fibrillation (AF). The purpose of this study was to evaluate the association between TGF-ß1 level and clinical factors before catheter ablation (CA), and to investigate the impact of TGF-ß1 level on the outcome after CA for AF. METHODS AND RESULTS: This prospective study included 151 patients (persistent AF group: n = 59, paroxysmal AF [PAF] group: n = 54, and control group: n = 38). All patients who underwent CA for AF were followed up for 12 months. The PAF group had the highest TGF-ß1 levels in all patients. An early recurrence of AF (ERAF: defined as episodes of atrial tachyarrhythmia within a 3-month blanking period) was detected in 60 patients (53%). Recurrent AF after the blanking period was detected in 36 patients (32%). On multivariate analysis, low TGF-ß1 level was the only independent factor associated with recurrent AF. Moreover, the AF recurrence ratio was higher in the low TGF-ß1 group (< 12.56 ng/mL) than in the high TGF-ß1 group (16 of 29 patients, 55% vs. 20 of 84 patients, 24%, P = 0.002 by log-rank test). CONCLUSIONS: PAF was associated with a higher TGF-ß1 level. Moreover, lower TGF-ß1 level in AF patients could be a cause of recurrent AF after CA.

Morphologic remodeling of left atrial appendage in patients with atrial fibrillation.

BACKGROUND: Left atrial appendage (LAA) has recently been of significant focus because of the development of the LAA closure device. OBJECTIVE: The purpose of this study was to test the hypothesis that atrial fibrillation (AF) leads to a morphologic change in the LAA and to investigate the characteristics of LAA morphology in patients with and without AF. METHODS: This retrospective study included 225 patients (persistent AF [PeAF], n = 76; paroxysmal AF [PAF], n = 70; control, n = 79] who underwent echocardiography and computed tomography (CT). All patients were classified into 2 types (chicken wing [CW] or non-chicken wing [non-CW]) using CT. RESULTS: The prevalence of non-CW-type LAA was 39.5%, 15.7%, and 8.9% in the PeAF, PAF, and control groups, respectively. Patients in the PeAF group had a higher prevalence of non-CW-type LAA than did those in the PAF and control groups (P = .0014 and P <.0001, respectively). In addition, all patients were divided into 5 groups based on the type of cardiac rhythm (PeAF, PAF, or sinus rhythm) and left atrial volume index (cutoff value; 34 mL/m(2)): group A (Control), group B (PAF/Small-LA), group C (PAF/Large-LA), group D (PeAF/Small-LA), group E (PeAF/Large-LA). The prevalence of non-CW-type LAA was 9%, 14%, 17%, 29%, and 41% in groups A, B, C, D, and E, respectively. CONCLUSION: Presence of persistent AF was associated with a higher prevalence of non-chicken wing-type LAA. Our analysis suggests that remodeling in patients with persistent AF can lead to a change in LAA morphology.

The Impact of Elevated Left Atrial Pressure in Sinus Rhythm After Cardioversion on Outcomes After Catheter Ablation for Atrial Fibrillation.

INTRODUCTION: Some patients with atrial fibrillation (AF) exhibit elevated left atrial pressure (LAP) in sinus rhythm (SR). The aim of the study was to investigate whether LAP changes between SR and AF are associated with outcomes after catheter ablation (CA) for AF. METHODS AND RESULTS: We retrospectively studied 110 patients (70 men, 66 ± 8 years, 37 with non-paroxysmal AF) who underwent CA of AF. In all patients, AF was induced by programmed stimulation and then terminated with cardioversion during CA. LAP was measured in SR and AF. The LAPSR-AF was defined as the difference between mean LAP in SR and mean LAP in AF (mean LAPSR - mean LAPAF ). Recurrence of AF after CA was detected in 37/110 patients (33.6%) during the follow-up period (13 ± 5 months). Univariate analysis revealed higher LAPSR-AF , larger left atrial diameter, and persistent AF (PeAF) as significant variables. On multivariate analysis, higher LAPSR-AF and PeAF were independently associated with recurrence of AF after CA. All patients were divided into the non-elevated LAPSR-AF group (LAPSR-AF <0 mmHg) or the elevated LAPSR-AF group (LAPSR-AF ≥0 mmHg) using the optimal cut-off value of LAPSR-AF . During a mean follow-up period of 13 ± 5 months, the AF recurrence ratio was higher in the elevated LAPSR-AF group than in the non-elevated LAPSR-AF group (20/42 patients, 48% vs. 17/68 patients, 25%, log-rank, P = 0.0306). CONCLUSION: Elevated LAP after cardioversion is associated with poor outcome after CA of AF. Sustained pressure overload of the LA in SR could be a cause of the recurrent AF.

The impact of left atrial pressure on filtered P-wave duration in patients with atrial fibrillation.

The cause of prolonged filtered P-wave duration (FPD) remains unclear in atrial fibrillation (AF) patients with normal left atrial size. We investigated whether FPD is associated with left atrial pressure (LAP) in AF patients without prominent LA enlargement. This study included 80 patients (48 men, age 65 ± 9 years, 25 persistent AF) with non-valvular AF who underwent catheter ablation (CA) for AF. LAP was measured in sinus rhythm during CA and signal-averaged electrocardiogram was recorded after CA. We retrospectively assessed the clinical and echocardiographic variables. Prolonged FPD was defined as FPD > 120 ms. Prolonged FPD (FPD > 120 ms) was detected in 23/80 patients (29 %). According to univariate analysis, higher mean LAP (14.9 ± 4.4 vs. 10.8 ± 3.5 mmHg, p < 0.0001), higher prevalence of persistent arrhythmia, higher BNP, larger LAD, higher E wave, and lower LVEF were associated with Prolonged FPD. According to multivariate analysis, higher mean LAP was the only factor associated with Prolonged FPD (p = 0.0058, OR 1.256 for each 1 mmHg increase in mean LAP, 95 % CI 1.068-1.476). Moreover, a significant correlation was observed between FPD and mean LAP (r = 0.503, p < 0.0001). Prolonged FPD is associated with high LAP in AF patients without prominent left atrial enlargement. Pressure overload of the left atria might cause slowing of atrial electrical activation.

Recurrent coronary artery dissection of left main trunk initially presented with normal coronary angiography.

Although spontaneous coronary artery dissection (SCAD) is usually diagnosed by coronary angiography, diagnosis may be missed because of various presentations and imperfections of coronary angiography. We report a case of a 41-year-old female with pregnancy-related SCAD who presented with cardiac arrest. Initial coronary angiography was normal without intimal flap. Unexpectedly, 4 days after admission, SCAD in left main trunk was revealed with recurrent myocardial infarction. Intimal flap was sealed at the time of first angiography and this is an interesting point that made us report this case. SCAD is a rare but not negligible cause of not only acute myocardial infarction but also sudden cardiac arrest even if first coronary angiography is normal. .

Does Left Atrial Appendage Morphology Influence Left Atrial Appendage Flow Velocity?

BACKGROUND: The shape of the left atrial appendage (LAA) might affect thrombus formation. The chicken wing-type LAA (CW) has been reported as unlikely to influence stroke events in atrial fibrillation (AF) patients, so we investigated whether LAA shapes could influence LAA function. METHODS AND RESULTS: We studied 102 patients (64 men, age 65±9 years) who underwent transthoracic echocardiography, transesophageal echocardiography (TEE), and cardiac computed tomography prior to catheter ablation (CA) for AF. LAA morphology were classified into 2 types: (1) CW: LAA with a bend in its shape and (2) non-CW type (NCW): LAA without any bends. All patients were classified into these groups using a cutoff value of LAA flow velocity (LAAFV). Patients with LAAFV <35 cm/s were classified as the low LAAFV group (Low FV, n=37). The patients with LAAFV >35 cm/s were classified as normal LAAFV group (Normal FV, n=65). The NCW type was detected in 25/102 patients (25%). In multivariate analysis, the patients with Low FV were associated with NCW type (P=0.0429, odds ratio [OR] 9.664, 95% confidence interval [CI] 1.075-86.900) and higher B-type natriuretic peptide (BNP) (P=0.0350, OR 1.012 for each 1 pg/ml increase in BNP, 95% CI 1.001-1.022). CONCLUSIONS: The NCW-type LAA and higher BNP were associated with lower LAAFV. One reason for the frequent cardiogenic stroke in patients with the NCW-type LAA may be the lower LAAFV.

Spontaneous subclavian venous occlusion before electronic device implantation.

BACKGROUND: Subclavian venous occlusion sometimes precludes the ability to insert leads during placement of a cardiac implantable electronic device. This study was performed to identify the risk factors for spontaneous subclavian venous occlusion prior to placement of an implantable electronic device. METHODS: We studied 446 patients who underwent axillary-subclavian venography to assess for occlusion and/or anomaly of the subclavian vein or associated veins before electronic device implantation. RESULTS: Six (1.3%) patients had venous occlusion (left subclavian vein in 5, left innominate vein in 1). There was a significantly higher incidence of previous cancer in the occlusion group than in the nonocclusion group (11.5% vs. 50%, p = 0.03). CONCLUSIONS: Subclavian venous occlusion may be present before cardiac implantable electronic device placement. A history of cancer represents a risk factor subclavian venous occlusion, and patients with this risk factor should undergo subclavian venography prior to electronic device placement.

Long QT syndrome caused by N-acetyl procainamide in a patient on hemodialysis.

A 65-year-old male on hemodialysis three times a week due to end-stage renal failure underwent cardiac surgery one year previously, and complained of breathlessness on exertion after surgery. Echocardiograms evidenced a significant obstruction in the left ventricular outflow with intraventricular pressure gradient of 62 mmHg, and the patient was started on beta-blocker. After a maximal dose of carvedilol was given, a class 1A antiarrhythmic drug of Na channel blocker, procainamide, was added because of insufficient relief of symptoms. Electrocardiogram (ECG) showed prolonged QT intervals (523 ms) on a regular visit one month after the administration of procainamide, and the dose of procainamide was decreased. On the next day, he was brought to our hospital due to cardiac pulmonary arrest. Initial rhythm was ventricular fibrillation and the corrected QT intervals (QTc) were prolonged (531 ms). Blood examination revealed that N-acetyl procainamide (NAPA), metabolite of procainamide, was significantly higher than the recommended threshold. NAPA was identified as the cause of prolonged QTc and procainamide was stopped. NAPA decreased under the recommended threshold on the seventh day and the QT intervals were normalized. This case report outlines the first case of long QT syndrome caused by NAPA in a hemodialysis patient. .

Impact of acute kidney injury on in-hospital outcomes in patients with DeBakey type III acute aortic dissection.

The relation between the incidence and severity of acute kidney injury (AKI) and clinical outcomes remains unclear in patients with DeBakey type III acute aortic dissection (AAD). We retrospectively assessed 56 patients admitted to our hospital for type III AAD within 48 hours of the onset of symptoms. The presence of AKI was identified, and its severity was staged on the basis of changes in serum creatinine (SCr) levels within 7 days after admission. We investigated the relations between AKI and clinical presentations, in-hospital complications, and predischarge renal function; AKI was observed in 20 patients (36%). After adjusting for age, gender, and body mass index, the incidence of AKI was associated with a history of hypertension, electrocardiographic ST-T changes, DeBakey type IIIb, and SCr level on admission. Maximum white blood cell count and serum C-reactive protein level were higher in patients with AKI than in those without AKI. AKI was associated with a greater incidence of in-hospital complications (70% vs 39%, p = 0.03) and higher SCr levels at discharge (1.1 [range 1.0 to 2.0] vs 0.9 [range 0.7 to 1.0] mg/dl, p = 0.0001). These associations were more pronounced in patients with relatively severe AKI. Multivariate analysis revealed that SCr level on admission and DeBakey type IIIb with renal artery involvement were major predictors of AKI. In conclusion, renal function on admission and renal artery involvement were significant risk factors for AKI, which was associated with poor outcomes and enhanced inflammatory response during hospitalization in patients with type III AAD.