Marehiko Ueda

Quality of coronary arterial 320-slice computed tomography images in subjects with chronic atrial fibrillation compared with normal sinus rhythm

PURPOSE To evaluate coronary arterial image quality on 320-slice CT in subjects with chronic atrial fibrillation (CAf) vs. normal sinus rhythm (NSR). MATERIALS AND METHODS In 92 consecutive subjects, 46 each with CAf (male:female ratio 2.54:1.00, age 69.7 ± 9.9 years) and NSR (male:female ratio 1.88:1.00, age 63.7 ± 13.7 years), 320-slice CT (Aquilion-one) was performed with enhanced images reconstructed at 80% of ECG R-to-R intervals. Visualized coronary vessels >1.5mm diameter in the right coronary artery, left anterior descending (LAD), and circumflex (LCx) distribution were evaluated for length, percentage of length free from motion artifacts, and image quality on a scale ranging from 1 (highest quality) to 5 (lowest quality). RESULTS LCx length measurements were significantly greater in subjects with NSR (108.8 ± 27.0mm) than CAf (96.6 ± 31.4mm) (P = 0.049), whereas percentages of length free from motion artifacts did not differ between the three vascular beds. Image quality, was significantly but marginally better overall in NSR than in CAF, as well as for LAD and LCx vascular beds. Mean scores in subjects with CAf and NSR were 1.4 ± 0.7 and 1.3 ± 0.6 in all arteries, 1.4 ± 0.7 and 1.2 ± 0.5 in LAD, and 1.5 ± 0.7 and 1.2 ± 0.5 in LCx, respectively (all P<0.001). Despite this difference in image quality, mean scores for both CAf and NSR were weighted toward the high quality end of the scale. CONCLUSION By 320-slice CT, the overall length of visualized coronary arteries, motion artifact-free length, and image quality using a 5-point scale showed values equal to or slightly lower in CAf than in NSR, but the absolute values were quite acceptable in both groups.

Left atrial wall thickness in paroxysmal atrial fibrillation by multislice-CT is initial marker of structural remodeling and predictor of transition from paroxysmal to chronic form

PURPOSE We used ECG-gated MSCT to evaluate alterations in the LA wall in patients with paroxysmal atrial fibrillation (AF) (PAF) and compared with chronic AF (CAF) and normal sinus rhythm (NSR). MATERIALS AND METHODS We enrolled 3 groups, each consisting of 62 patients with either recurrent PAF (48 males, 65 ± 11 years), CAF (43 males, 69 ± 9 years), or NSR without any history of AF (40 males, 64 ± 11 years) for a total of 186 study patients. In CT, the absolute LA wall thickness (LAT) and LA volumes were calculated. RESULTS In CT, patients with PAF had significantly thicker LAT than those with either CAF or NSR (2.4 ± 0.2mm in PAF >2.1 ± 0.2mm in CAF or 1.9 ± 0.2mm in NSR, p<0.01). Patients with CAF had significantly larger LA volume than those with either PAF or NSR (p<0.01). Subsequently, 9 of the 62 patients with PAF developed CAF over a mean follow-up period of 19 ± 22 months. The mean LAT was significantly thinner in patients who had transitioned from PAF to CAF than in those who had not (2.2 ± 0.2mm and 2.4 ± 0.2mm, respectively) (p<0.01). Receiver operating characteristic analysis demonstrated that the area under the curve for LAT was greater than that for LA volume in CT and LAD in transthoracic echocardiogram. In the Kaplan-Meier analysis, the transition from PAF to CAF was observed more frequently in patients with LAT<2.4mm than LAT ≥ 2.4mm (p=0.018). CONCLUSIONS Alteration of the LA wall may suggest a part of structural remodeling in AF before the occurrence of LA dilatation. LAT in CT seems to be a useful predictor of the transition from PAF to CAF in patients with PAF.

Prevalence and Characteristics of Idiopathic Outflow Tract Tachycardia with QRS Alteration Following Catheter Ablation Requiring Additional Radiofrequency Ablation at a Different Point in the Outflow Tract

Subtle variations in QRS morphology occurs during idiopathic outflow tract ventricular tachycardia (OTVT), but no studies have clarified the prevalence and characteristics of the OTVT with altered QRS morphology following radiofrequency catheter ablation (RFA), which then require an additional RF application at a different portion of the outflow tract to abolish OTVT. Of 202 patients with a monomorphic VT or premature ventricular contraction (PVC) originating from the outflow tract, 6 (3%) showed changes in QRS morphology in the OTVT following RFA, requiring an additional RF application to the outflow tract at a different portion. In all six patients, RFA was applied for the first or second OTVT to a right or left ventricular endocardial site, with the other site being the left sinus of Valsalva. In each patient, OTVT before or after the changes in QRS morphology had characteristic ECG findings originating from a particular portion of the outflow tract. Changes in QRS morphology consistently included an increase or decrease in R wave amplitude in all inferior leads. Detailed continuous observation of QRS morphology in OTVT, especially R wave amplitude in inferior leads, is important for identifying changes of QRS morphology during catheter ablation. Mapping and ablation at a different portion of the outflow tract is then needed for cure.

Significance of two potentials for predicting successful catheter ablation from the left sinus of Valsalva for left ventricular epicardial tachycardia.

The aim of this study was to identify the characteristics of electrograms that may be helpful in predicting successful ablation of idiopathic ventricular tachycardia from the aortic sinus of Valsalva. Data were obtained from 23 patients with symptomatic ventricular tachycardia or premature ventricular contractions (LV‐VT) who underwent RF catheter ablation from the left sinus of Valsalva. Electrograms before and after application of RF energy during sinus rhythm and during LV‐VT were analyzed. Complete elimination of LV‐VT was finally achieved in 21 (91%) patients. The incidence of presystolic potentials preceding the QRS complex of LV‐VT (P1 potential) was 90% for the 21 successful ablation sites, which did not differ from the incidence for the 24 unsuccessful sites (79%; P = 0.5). During sinus rhythm, a potential following the QRS complex (P2 potential) was more often recorded at the successful ablation site than at an unsuccessful ablation site before and after application of RF energy (before, P < 0.05; after, P < 0.001). The appearance of the P2 potential or a delay in the preexisting P2 potential after application of RF energy was observed only at the successful ablation sites (P < 0.001). In 18 control individuals who had no LV‐VT, no P2 potential was recorded within the left sinus of Valsalva. Although the P1 potential may be useful for identifying the successful ablation site, its sensitivity is low. The appearance of the P2 potential or an increasingly delayed P2 potential after application of RF energy may be more useful than the P1 potential for predicting successful ablation.

Simultaneous Mapping in the Left Sinus of Valsalva and Coronary Venous System Predicts Successful Catheter Ablation from the Left Sinus of Valsalva

Idiopathic ventricular tachycardia originating from the left epicardium (Epi‐VT) can be ablated from the left sinus of Valsalva (LSV) in selected patients. We hypothesized that the analysis of electrograms at the LSV and transitional zone from the great cardiac vein to the anterior interventricular vein (GCV‐AIV) could predict the efficacy of radiofrequency catheter ablation (RFCA) from the LSV. Simultaneous mapping in the LSV and coronary venous system was performed in 25 patients (12 VTs and 13 premature ventricular contractions). The earliest ventricular activation (VA) during the arrhythmias was found at the LSV or GCV‐AIV in all patients. RF applications from the LSV were successful in 17 patients success group (S‐Gr) and failed in 8 failure group (F‐Gr). The earliness of the VA recorded in the LSV (VA[LSV]) and in GCV‐AIV (VA[GCV‐AIV]) was compared between the two groups. (1) The VA[LSV] preceded the QRS onset by 28 ± 11 ms in S‐Gr and 14 ± 10 ms in F‐Gr (P < 0.01). (2) In S‐Gr, the VA[GCV‐AIV] was earlier than the VA[LSV] in 5 five patients (35%). However, in F‐Gr, the VA[GCV‐AIV] was earlier than the VA[LSV] in all patients. (3) In patients in whom the earliest VA was found at the LSV or GCV‐AIV, a VA [GCV‐AIV] preceding the VA[LSV] by less than 10 ms identified successful RFCA from the LSV with a sensitivity of 88 %, specificity of 100%, and high predictive value. With a detailed analysis of the electrograms recorded from the GCV‐AIV and LSV, it was possible to identify the successful catheter ablation of Epi‐VT from the LSV.

Right-Sided Heart Wall Thickening and Delayed Enhancement Caused by Chronic Active Myocarditis Complicated by Sustained Monomorphic Ventricular Tachycardia

An asymptomatic healthy 65-year-old man was referred to a hospital for inverted T waves in the precordial leads (Figure 1) with paroxysmal advanced atrioventricular block in the ECG. Chest x-ray showed mild cardiac enlargement (Figure 2), and an echocardiogram showed right ventricular (RV) wall thickening (arrow in Figure 3). Five months later, the patient was referred to another hospital complaining of chest discomfort. Coronary angiogram was normal, but sustained monomorphic ventricular tachycardia (VT) occurred. Suffering from incessant VT, the patient was transferred to our hospital. The ECG and echocardiogram were …

Cardiac sarcoidosis complicated with atrioventricular block and wall thinning, edema and fibrosis in left ventricle: Confirmed recovery to normal sinus rhythm and visualization of edema improvement by administration of predonisolone

A 65 year-old female had a node of some kind in her right leg five years ago and was diagnosed with sarcoidosis by gallium scintigraphy. Serum angiotension-converting enzyme levels had gradually increased, and three months ago she felt palpitations and dizziness when standing. On electrocardiogram, 2:1 atrioventricular (AV) block was observed. On transthoracic echocardiogram, the basal portion of the interventricular septum (IVS) revealed wall thinning with dyskinetic motion and lack of systolic thickening, and low attenuation. The basal portion of the left ventricular (LV) posterior inferior wall revealed mild wall thickening with low attenuation. Enhanced multislice-CT revealed a thickened LV posterior wall and thinned basal portion of IVS with interstitial change suggesting presence of fibrosis or edema. Late enhancement was also observed in the basal portion of the LV posterior inferior wall and basal IVS in T1 weighted magnetic resonance imaging (MRI); in addition, an area, the center of which indicated low attenuation surrounded by high attenuation, was observed in the basal portion of the LV posterior inferior wall in T2 weighted MRI. Positron emission tomography (PET) imaging using F-18 fluoro-deoxyglucose with the subject fasted for 6 h beforehand, revealed strong uptake in the basal portion of IVS and a thickened LV posterior wall, suggesting the presence of inflammation. Administration of predonisolone was started before pacemaker implantation and clinical symptoms immediately disappeared; in addition AV block recovered to normal sinus rhythm. On a repeat MRI performed four months later, the late enhancement in T1 weighted MRI and the high attenuation surrounding low attenuation in the basal portion of the LV posterior inferior wall in T2 weighted MRI both disappeared, and we confirmed that temporary edema had also disappeared.

Estimation of the origin of ventricular outflow tract arrhythmia using synthesized right-sided chest leads

AIMS For successful ablation of ventricular outflow tract arrhythmia, estimation of its origin prior to the procedure can be useful. Morphology and lead placement in the right thoracic area may be useful for this purpose. Electrocardiography using synthesized right-sided chest leads (Syn-V3R, Syn-V4R, and Syn-V5R) is performed using standard leads without any additional leads. This study evaluated the usefulness of synthesized right-sided chest leads in estimating the origin of ventricular outflow tract arrhythmia. METHODS AND RESULTS This retrospective study included 63 patients in whom successful ablation of ventricular outflow tract arrhythmia was performed. Numbers of arrhythmias originating from the left ventricle, the septum of the right ventricle, and the free wall of the right ventricle were 11, 40, and 13, respectively. In one patient, two different left ventricular outflow tract origins were found. Electrocardiographic recordings from right-sided chest leads were divided into three types as follows: those in which an R > S concordance, a transitional zone, or an R < S concordance were detected. In all left arrhythmia cases, R > S concordance was observed. A transitional zone was evident in 34 of 40 cases of right ventricular outflow tract arrhythmia originating in the ventricular septum, and an R < S concordance was observed in 6 of the 40 cases. However, an R < S concordance was found in all cases of right ventricular outflow tract arrhythmia originating in the free wall. CONCLUSION Synthesized right-sided chest lead electrocardiography may be useful for estimating the origin of ventricular outflow tract arrhythmia.

Positive influence of aging on the occurrence of fat replacement in the right ventricular myocardium determined by multislice-CT in subjects with atherosclerosis

PURPOSE We evaluated predictors of fat replacement (FR) in the right-ventricular-myocardium (RVM) determined by MSCT in atherosclerotics not receiving anti-arrhythmia drugs and evaluated the relationship between the presence of FR in the RVM and the occurrence of ventricular premature beats (VPB). MATERIALS AND METHODS 120-consecutive-atherosclerotics (101-males, 11-85 years) not receiving anti-arrhythmia drugs for VPB, who underwent MSCT for evaluating atherosclerosis and Holter-ECG within one-month, were retrospectively analyzed for FR in the RVM and its relationship with age, body mass index (BMI), and occurrence of VPB. RESULTS 31-subjects had FR in RVM (18-males; median 67 years), and 89 did not (53-males, median 56 years). Median age was significantly higher in subjects with FR in RVM (P<0.01). The median BMI was 23.0 in subjects with FR and 23.0 in those without (not significant). Average number of VPB by Holter-ECG was 1445 in 31 subjects with FR. Without FR, the average number of VPB was 995. The difference in the numbers of VPB was not significant (P=0.73). A logistic-regression-model using age, male sex and BMI indicated that age was associated with an increased incidence of FR in the RVM (relative risk=1.055, 95% CI 1.019-1.092, P<0.05). CONCLUSIONS Age but not BMI is significantly associated with the presence of FR in the RVM. Aging might have a positive influence on the occurrence of FR in the RVM as determined by MSCT in atherosclerotics, but FR in the RVM had no influence on the occurrence of VPB.

Occurrence of Multiple Fibrofatty Replacements Exclusively in the Left Ventricle of a Patient With Monomorphic Sustained Ventricular Tachycardia

A 34-year-old man presented with cardiovascular syncope with sustained ventricular tachycardia (VT). ECG showed VT with morphologically right bundle-branch block with a-superior-axis. Cardioversion and endotracheal intubation were performed. After resolution of VT, a 12-lead ECG showed sinus rhythm, normal axis deviation, and isolated premature ventricular contraction of right bundle-branch block morphology with a-superior-axis. The transthoracic echocardiogram showed regional abnormality of contraction in the posterior area of the left ventricle with no abnormality of the right ventricle. Obstructive coronary heart disease was excluded by angiography …