Koji Fukuzawa

Myocardial Contractile Function in the Region of the Left Ventricular Pacing Lead Predicts the Response to Cardiac Resynchronization Therapy Assessed by Two-Dimensional Speckle Tracking Echocardiography

BACKGROUND The aim of this study was to test the impact of posterolateral myocardial systolic function on response to cardiac resynchronization therapy (CRT). METHODS Forty patients were studied before and 4 +/- 2 months after CRT. Dyssynchrony was defined as anteroseptal wall-to-posterior wall delay (> or = 130 ms) caused by speckle-tracking radial strain. The average longitudinal strain in 4 posterior and lateral segments (epsilon-pl) in which the left ventricular pacing lead was positioned was calculated by automated functional imaging. Response to CRT was defined as a > or = 15% decrease in end-systolic volume. RESULTS The negative value of epsilon-pl in responders was significantly higher than that in nonresponders at baseline (-7.8 +/- 6.9% vs -2.1 +/- 4.9%, P < .01). Combining dyssynchrony with epsilon-pl < -7.8% was more effective for predicting response to CRT than dyssynchrony parameters alone (92% vs 75%). CONCLUSION The addition of posterolateral myocardial systolic function to the measurement of dyssynchrony appears to be of value for predicting response to CRT.

Circulating intermediate CD14++CD16+monocytes are increased in patients with atrial fibrillation and reflect the functional remodelling of the left atrium

Aims A recent large clinical study demonstrated the association between intermediate CD14++CD16+monocytes and cardiovascular events. However, whether that monocyte subset contributes to the pathogenesis of atrial fibrillation (AF) has not been clarified. We compared the circulating monocyte subsets in AF patients and healthy people, and investigated the possible role of intermediate CD14++CD16+monocytes in the pathophysiology of AF. Methods and results This case–control study included 44 consecutive AF patients without systemic diseases referred for catheter ablation at our hospital, and 40 healthy controls. Patients with systemic diseases, including structural heart disease, hepatic or renal dysfunction, collagen disease, malignancy, and inflammation were excluded. Monocyte subset analyses were performed (three distinct human monocyte subsets: classical CD14++CD16−, intermediate CD14++CD16+, and non-classical CD14+CD16++monocytes). We compared the monocyte subsets and evaluated the correlation with other clinical findings. A total of 60 participants (30 AF patients and 30 controls as an age-matched group) were included after excluding 14 AF patients due to inflammation. Atrial fibrillation patients had a higher proportion of circulating intermediate CD14++CD16+monocytes than the controls (17.0 ± 9.6 vs. 7.5 ± 4.1%, P < 0.001). A multivariable logistic regression analysis demonstrated that only the proportion of intermediate CD14++CD16+monocytes (odds ratio: 1.316; 95% confidence interval: 1.095–1.582, P = 0.003) was independently associated with the presence of AF. Intermediate CD14++CD16+monocytes were negatively correlated with the left atrial appendage flow during sinus rhythm (r= −0.679, P = 0.003) and positively with the brain natriuretic peptide (r = 0.439, P = 0.015). Conclusion Intermediate CD14++CD16+monocytes might be closely related to the pathogenesis of AF and reflect functional remodelling of the left atrium.

Time-dependent effect of cardiac resynchronization therapy on ventricular repolarization and ventricular arrhythmias.

AIMS Cardiac resynchronization therapy (CRT) improves the clinical status of patients with congestive heart failure, although left ventricular epicardial pacing may increase transmural dispersion of repolarization (TDR). The aim of this study was to investigate the time-dependent effect of CRT on ventricular repolarization and ventricular arrhythmia at mid-term follow-up. METHODS AND RESULTS The study group consisted of 84 patients treated with CRT. Twelve-lead electrocardiogram was digitally recorded and Tpeak-to-Tend interval (Tp-e) was measured at baseline, 1 week, 1 month, and 3, 6, and 12 months after device implantation. We determined the time-dependent changes in Tp-e, ventricular tachycardia and ventricular fibrillation (VT/VF) during 12 months of follow-up, in both CRT responders and non-responders. Seventeen of 84 patients (20%) had VT/VF during first year. Six of those 17 patients (35%) experienced VT/VF within 1 month of implantation and diminished over time. Tp-e decreased significantly at 6 and 12 months after implantation compared with 1 week [108 ± 14 ms at 1 week vs. 97 ± 21 ms at 6 months (P = 0.03) and 95 ± 19 ms at 12 months (P = 0.01)]. Responders demonstrated a greater time-dependent reduction of Tp-e at 6 and 12 months of CRT and had a lower rate of VT/VF compared with non-responders (log-rank test, P = 0.004). CONCLUSION Transmural dispersion of repolarization and the number of patients with VT/VF decreased over time after CRT. Patients with reverse remodelling demonstrated a lower rate of VT/VF and a greater time-dependent reduction of TDR.

Clinical Structural Anatomy of the Inferior Pyramidal Space Reconstructed Within the Cardiac Contour Using Multidetector‐Row Computed Tomography

Although many studies have described the detailed anatomy of the inferior pyramidal space, it may not be easy for cardiologists who have few chances to study cadaveric hearts to understand the correct morphology of the structure. The inferior pyramidal space is the part of extracardiac fibro‐adipose tissue wedging between the 4 cardiac chambers from the diaphragmatic surface of the heart. Many cardiologists have interests in pericardial adipose tissue, but the inferior pyramidal space seems to have been neglected. A number of important structures, including the coronary sinus, atrioventricular node, atrioventricular nodal artery, membranous septum, muscular atrioventricular sandwich (previously called the “muscular atrioventricular septum”), atrial septum, ventricular septum, aortic valvar complex, mitral valvar attachment, and tricuspid valvar attachment are associated with the inferior pyramidal space. We previously revealed its 3‐dimensional live anatomy using multidetector‐row computed tomography. Moreover, the 3‐dimensional understanding of the anatomy in association with the cardiac contour is important from the viewpoints of clinical cardiac electrophysiology. The purpose of this article is to demonstrate extended findings regarding the clinical structural anatomy of the inferior pyramidal space, which was reconstructed in combination with the cardiac contour using multidetector‐row computed tomography, and discuss the clinical implications of the findings.

Optimal angulations for obtaining an en face view of each coronary aortic sinus and the interventricular septum: Correlative anatomy around the left ventricular outflow tract

An optimal image intensifier angulation used for obtaining an en face view of a target structure is important in electrophysiologic procedures performed around each coronary aortic sinus (CAS). However, few studies have revealed the fluoroscopic anatomy of the target area. This study investigated the optimal angulation for each CAS and the interventricular septum (IVS). The study included 102 consecutive patients who underwent computed tomography coronary angiography. The optimal angle for each CAS was determined by rotating the volume‐rendered image around the vertical axis. The angle formed between the anteroposterior axis and IVS was measured using the horizontal section. The frontal direction was defined as zero, positive, or negative if the en face view of the target CAS was obtained in the frontal view, left anterior oblique (LAO) direction, or right anterior oblique (RAO) direction, respectively. The optimal angles for the left, right, and non‐CASs were 120.3 ± 10.5°, 4.8 ± 16.3°, and −110.0 ± 13.8°, respectively. The IVS angle was 42.6 ± 8.5°. Accordingly, the optimal image intensifier angulations for the left, right, and non‐CASs and the IVS were estimated to be RAO 60°, LAO 5°, LAO 70°, and RAO 50°, respectively. The IVS angle was the most common independent predictor of the optimal angle for each CAS. Differences in the optimal angulations for each CAS and the IVS are demonstrated. The biplane angulation needs to be tailored according to the individual patients and target structures for electrophysiologic procedures. Clin. Anat. 28:494–505, 2015.

Dilated phase of hypertrophic cardiomyopathy caused by Fabry disease with atrial flutter and ventricular tachycardia.

We describe a case of a 60-year-old male with dilated phase of hypertrophic cardiomyopathy caused by Fabry disease. He was diagnosed to have a cardiac variant of Fabry disease by an enzyme assay and a right ventricular endomyocardial biopsy which revealed specific features of this disease and cardiac involvement was the sole manifestation. He has developed dilated cardiomyopathy with sustained atrial flutter and frequent non-sustained ventricular tachycardia requiring isthmus ablation and cardiac resynchronization therapy with defibrillator.

Impact of esophageal temperature monitoring guided atrial fibrillation ablation on preventing asymptomatic excessive transmural injury

Even with the use of a reduced energy setting (20–25 W), excessive transmural injury (ETI) following catheter ablation of atrial fibrillation (AF) is reported to develop in 10% of patients. However, the incidence of ETI depends on the pulmonary vein isolation (PVI) method and its esophageal temperature monitor setting. Data comparing the incidence of ETI following AF ablation with and without esophageal temperature monitoring (ETM) are still lacking.

Topographic variability of the left atrium and pulmonary veins assessed by 3D-CT predicts the recurrence of atrial fibrillation after catheter ablation☆

Catheter ablation (CA) is an established therapy for atrial fibrillation (AF). However, the assessment of anatomical information and predictors of AF recurrence remain unclear. We investigated the relationship between anatomical information on the left atrium (LA) and pulmonary veins (PVs) from three‐dimensional computed tomography images and the recurrence of AF after CA.

Discrepancy between electrical and mechanical dyssynchrony in patients with heart failure and an electrical disturbance.

Cardiac resynchronization therapy (CRT) improves the survival rates of patients with heart failure, but 30–40% of them do not respond to CRT, partially because of the position of the left ventricular (LV) lead. The relationship between the electrical and mechanical activation of the left ventricle is unknown. The aim of this study was to compare the electrical and mechanical dyssynchrony.

Clinical cardiac structural anatomy reconstructed within the cardiac contour using multidetector‐row computed tomography: Atrial septum and ventricular septum

Cardiologists are increasingly becoming involved in procedures associated with the atrial septum and ventricular septum, such as transseptal puncture and selective site pacing. Moreover, detailed knowledge about the architecture of the atrial septum and ventricular septum is now available from studies by radiologists and anatomists. However, from the viewpoint of clinical cardiologists, many questions about the three‐dimensional cardiac structural anatomy that relate closely to routine invasive procedures remain unresolved. Although modern multidetector‐row computed tomography could provide answers, interventional cardiologists might have not considered the potential of this equipment, as only a few have performed studies with both radiological imaging and cadaveric hearts. Detailed knowledge of the three‐dimensional fluoroscopic cardiac structural anatomy could help to reduce the need for contrast medium injection and radiation exposure, and to perform safe interventions. In this article, we present a series of cardiac structural images, including images of the atrial septum and ventricular septum, reconstructed in combination with the cardiac contour using multidetector‐row computed tomography. We also discuss the clinical implications of the findings on the basis of accumulated insights of research pioneers. We hope that the present images will serve as a bridge between the fields of cardiology, radiology, and anatomy, and encourage cardiologists to integrate their accumulated insights into the three‐dimensional clinical images of the living heart. Clin. Anat. 29:342–352, 2016.