Taichi Murayama

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.

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 …

New classification of aortic dissection during the cardiac cycle as pulsating type and static type evaluated by electrocardiogram-gated multislice CT

PURPOSE In some four-dimensional images acquired by electrocardiogram (ECG)-gated multislice computed tomography (MSCT) of thoracic aortic dissection (AD), true lumen (TL) gets larger (pulsating-type), whereas in others, TL and false lumen (FL) do not change (static-type) in a cardiac cycle. We have characterized these types. MATERIALS AND METHODS Twenty subjects (10 with a double-barrel type thoracic descending AD and 10-controls) were enrolled. MSCT covered the thorax, and reconstructed every 10% from 0-90% of the R-R interval. Two physicians measured the TL and FL areas of descending thoracic aorta for each phase at 1) left-pulmonary-artery, 2) left-main-coronary-artery, and 3) right-coronary-artery levels. RESULTS By designating the pulsating-range acquired from the control data as normal, AD subjects were classified as pulsating or static type when the maximum area of TL was >125% of the minimum TL area at any of the 3 levels. Five subjects were classified as pulsating and 5 as static-type AD. Excluding those with entry at the distal portion of the descending-thoracic-aorta with retrograde flow in FL, the mean-period from onset was 4.3+/-5.9 in the pulsating-type and 42.0+/-13.0 months in the static-type (P<0.05). Percentages with entry at the distal-portion of the descending-thoracic-aorta with retrograde flow in FL in the pulsating-type and static-type were 0% and 40%, respectively. CONCLUSION In AD, pulsating-type is more common if in the acute-phase from onset or the entry is not located at the distal-portion of descending-thoracic-aorta with retrograde flow in FL. This new classification of AD may usefully differentiate unstable-AD affected by cardiac pulsation from stable-AD.

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.

Relations between Glomerular Filtration Rate of Chronic Kidney Disease with Cardiac Size and Function in Patients with Chronic Atrial Fibrillation

Purpose: Decreased estimated glomerular filtration rate (eGFR) and atrial fibrillation (AF) share risk factors on cardiovascular event, and renal dysfunction is thought to be associated with the new-onset of AF. However, there had been few studies about relations between eGFR and chronic AF. Methods: Of 218 consecutive subjects with episode of AF, 67 chronic AF patients with chronic kidney disease (CKD) defined as decreased eGFR (<60 ml/min per 1.73 m−2) and were evaluated. These were divided into following three groups according to degree of eGFR: Gr-1) 45 to 60 ml/min per 1.73 m−2, Gr-2) 30 to 45 ml/min per 1.73 m−2, Gr-3)<30 ml/min per 1.73 m−2. Baseline demographic, clinical and echocardiographic characteristics were analyzed. Results: There was no difference in the presence of structural heart disease, left ventricular (LV) function and left atrial diameter by echocardiography, use of oral medications and heart failure hospitalization among the 3 groups. However, male gender (100 vs 79 vs 56 [%], respectively, P<0.001) and hemoglobin level (13.1±2.1 vs 12.3±1.8 vs 10.9±2.6 [g/dl], respectively, P<0.05) were higher in Gr 1) than Gr 2) or Gr 3). During 4±2 year follow-up, no significant change of LV function could be found between baseline and follow-up in all groups. Kaplan-Meier curves revealed that the cumulative survival rate was not difference among groups (96 vs 83 vs 88 [%], log rank test; P=NS). Conclusions: Sole kidney dysfunction had no influence to cardiac size, function and the survival of chronic AF patients.

Clinical Prognosis of Early Repolarization on Electrocardiography in Survivors after out of Hospital Cardiopulmonary Arrest

Purpose: An early repolarization (ER) in inferior leads on electrocardiography (ECG) has been shown to be associated with an increased risk of ventricular arrhythmias. However, ECG findings on ER after resuscitation of cardiopulmonary arrest (CPA) subjects are unknown. Methods: Of 448 consecutive subjects with out-of-hospital CPA for the last 2 years, 118 subjects were resuscitated. Among them, 64 subjects (35 male, 76±14 years) who had no evident of acute ischemia or vascular deseases were evaluated and divided into two groups: 1) with early repolarization in inferior leads 2) without those findings. Baseline demographic, clinical and electrocardiographic characteristics were analyzed. Early repolarization was defined as >0.1 mV J-point elevation of the QRS-ST junction in at least two leads in inferior leads as QRS slurring or notching, and was stratified according to the degree of J-point elevation (>0.1 mV or >0.15 mV). Results: ER was detected in 23 subjects. There was no significant difference in patient baseline characteristics between two groups. However, 11 subjects with more than 0.15 mV J-point elevation of Group 1 had markedly lower in survival time than the Group 2 (2.8±3.7 vs 8.8±17.1 [days], P=0.045), and more than 5 days survival after resuscitation was significantly increased in Group 2 compared with those subjects in Group 1 (29 vs 18 [%], P=0.043). Conclusions: Greater degree of early repolarization in the inferior leads of ECG after resuscitation might suggest the poor prognosis in the CPA subjects.