Takanao Mine

Prediction of sudden death in patients with mild-to-moderate chronic heart failure by using cardiac iodine-123 metaiodobenzylguanidine imaging

Objective: To evaluate the usefulness of cardiac iodine-123 (123I) metaiodobenzylguanidine (MIBG) imaging as a predictor of sudden death in patients with chronic heart failure (CHF). Design and setting: Prospective cohort study in a tertiary referral centre. Patients: 97 outpatients with CHF with a radionuclide left ventricular ejection fraction <40% (mean (SD) 29% (7.5%)). Interventions: At study entry, cardiac I-123 MIBG imaging was performed. The cardiac MIBG heart-to-mediastinum ratio (H/M) and washout rate (WR) were obtained from MIBG imaging. Main outcome measures: Patients were assigned to two groups based upon 27% of WR, which was the mean (2SD) control WR. 48 of 97 patients with CHF had abnormal WR (⩾27%), whereas the remaining 49 patients had normal WR (<27%). All the study patients were then followed up. Results: During the mean (SD) follow-up period of 65 (29) months, 12 (25%) patients in the abnormal WR group and 2 (4%) patients in the normal WR group died suddenly. Kaplan–Meier analysis revealed that sudden death was more often observed in patients with abnormal WR than those with normal WR (p = 0.001). On Cox regression analysis, MIBG WR, H/M on the delayed image and H/M on the early image were significantly associated with sudden death. Conclusion: Cardiac MIBG imaging would be useful for predicting sudden death in patients with CHF.

Beat-to-beat QT interval variability is primarily affected by the autonomic nervous system.

Background: Beat‐to‐beat QT interval variability is associated with life‐threatening arrhythmias and sudden death, however, its precious mechanism and the autonomic modulation on it remains unclear. The purpose of this study was to determine the effect of drugs that modulate the autonomic nervous system on beat‐to‐beat QT interval.

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.

The impact of elevated left atrial pressure in sinus rhythm after cardioversion on outcomes after catheter ablation for atrial fibrillation

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.

Effect of right ventricular pacing site on QRS Width

To assess the effect of various right ventricular pacing sites on QRS duration, we enrolled 50 patients (mean age, 64 ± 13 years; 36 men); 16 had bradycardia and 34 had tachycardia. The right ventricle was arbitrarily divided into 5 sections: high and low right ventricular outflow tract, mid septum, low septum, and apex. Right ventricular pacing was performed using an electrode catheter at each of the 5 sites. QRS duration was 162 ± 20 ms during high right ventricular outflow tract pacing, 143 ± 17 ms during low right ventricular outflow tract pacing, 151 ± 20 ms during mid-septal pacing, 163 ± 16 ms during low-septal pacing, and 167 ± 18 ms during apical pacing. Paced QRS duration was shorter during low right ventricular outflow tract and mid-septal pacing compared to apical pacing in 34 patients. There was a difference of 10 ms or less in the paced QRS duration between these pacing sites in the other 16 patients. QRS duration was shortest when the septum was paced in the right ventricle. However, QRS duration was similar during pacing in the septum and the apex in 32% of patients.

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.

An unexpected vein draining into the left atrial roof

We investigated left atrium (LA) morphology using multidetector computed tomography in 500 patients and found 2 patients with an …

Atorvastatin therapy associated with improvement in left ventricular remodeling in a case of idiopathic dilated cardiomyopathy.

Statins have pleiotropic effects such as anti-inflammatory and vascular protective effects that would be beneficial for patients with chronic heart failure. This report describes a patient with idiopathic dilated cardiomyopathy and a long-standing history of heart failure that was treated with atorvastatin in addition to conventional therapy that included beta-blockers. Atorvastatin therapy for 12 months was associated with an improvement in cardiac function and improved left ventricular remodeling and peak oxygen consumption. This result suggests that statin therapy may be a potential novel treatment strategy for patients with chronic heart failure.

The Impact of Transforming Growth Factor‐β1 Level on Outcome After Catheter Ablation in Patients With Atrial Fibrillation

Transforming growth factor‐β1 (TGF‐β1) is an important factor that induces atrial fibrosis and atrial fibrillation (AF). The purpose of this study was to evaluate the association between TGF‐β1 level and clinical factors before catheter ablation (CA), and to investigate the impact of TGF‐β1 level on the outcome after CA for AF.

Efficacy of Intensive Radiofrequency Energy Delivery to the Localized Dense Scar Area in Post-Infarction Ventricular Tachycardia Ablation ― A Comparative Study With Standard Strategy Targeting the Infarcted Border Zone ―

BACKGROUND Several reports have demonstrated the importance of severely low voltage areas as arrhythmogenic substrates of ventricular tachycardia (VT). However, a comparative study of dense scar-targeted and infarcted border zone-targeted strategies has not been reported.Methods and Results:We divided 109 consecutive patients with VT post-infarction from 6 centers into 2 groups according to the ablation strategy used: dense scar-targeted ablation (DS ablation, 48%) or border zone-targeted ablation (BZ ablation, 52%). During DS ablation, we attempted to identify VT isthmuses in the dense scar areas (≤0.6 mV) using detailed pace mapping, and linear ablation lesions were applied mainly to those areas. During BZ ablation, linear ablation of standard low voltage areas (0.5-1.5 mV) was performed along with good pace map sites of the clinical VT. Acute success was defined as complete success (no VTs inducible) or partial success (clinical VT was noninducible). The acute complete success rate was significantly higher for DS ablation than for BZ ablation (62% vs. 42%, P=0.043). During a median follow-up of 37 months, the VT-free survival rate was significantly higher for DS ablation than for BZ ablation (80% vs. 58% at 48 months; log-rank P=0.038). CONCLUSIONS DS ablation may be a more effective therapy for post-infarction VT than BZ ablation in terms of the acute complete success rate and long-term follow-up.