Clinical outcomes of spinal cord stimulation in patients with intractable leg pain in Japan.

BACKGROUND: Neuromodulation through spinal cord stimulation (SCS) is a therapeutic option for relieving leg pain and improving the chances of limb salvage in patients with intractable chronic limb-threatening ischemia (CLTI); however, there is no consensus on its indications. OBJECTIVE: The aim of this study was to assess the clinical outcomes of SCS in patients with intractable leg pain caused by various diseases treated in the department of cardiovascular medicine in Japan. METHODS: This was a retrospective study of patients who underwent SCS for pain management. Patients were considered eligible for the therapy if they met the following criteria: (1) intractable leg pain (numerical rating scale [NRS] score of 10), (2) no revascularization option, and (3) no septicemia. RESULTS: Twenty patients (mean age: 77 years; men/women: 11/9) were included in this study. The NRS score of the patients significantly reduced from 10 ± 0 before procedure to 4 ± 3 at discharge (p < 0.001). The clinical response rate of the entire cohort was 65% (13/20) at 17 ± 14 months after implantation; however, patients with intractable CLTI showed a low response rate (45%), whereas those with subacute limb ischemia showed a high response rate (100%). A multivariable regression analysis showed that hemoglobin level was significantly associated with treatment response, even after adjusting for age and sex (p = 0.026). The area under the receiver operating characteristic curve for the correlation between hemoglobin level (cutoff, 11.4 g/dL) and clinical response to SCS was 0.824 (0.619-1). CONCLUSIONS: SCS can reduce clinical symptoms in majority of patients with intractable leg pain. Although implantation of an SCS device has been shown to improve microvascular perfusion insufficiency, the correlation between hemoglobin level and the clinical effect of SCS indicates that a preserved microcirculatory vascular bed is essential for the therapy to be effective.

Impact of Sex in Left Atrial Indices for Prognosis of Heart Failure with Preserved Ejection Fraction.

OBJECTIVE: We aim to clarify the differences in the association between re-admission for heart failure (HF) and left atrial (LA) overload indices by sex in heart failure and a preserved ejection fraction (HFpEF). METHODS: We analyzed 898 HFpEF patients hospitalized for acute decompensated HF. Blood tests and transthoracic echocardiography were performed before discharge. The primary endpoint was re-admission for HF during the first year. RESULTS: The ratio of diastolic elastance to arterial elastance (p = 0.014), a relative index of LA pressure overload, in men and LA volume index (LAVI, p = 0.020) in women were significant for re-admission for HF during the first year in the multivariable Fine-Gray analysis. Stroke volume (SV)/LA volume (LAV), another index for LAV overload, was not a significant prognostic factor of re-admission for HF during this time. CONCLUSION: LA overload was an important prognostic factor for HF re-readmission during the first year after enrolment in patients with HFpEF, but the indices relating to LA overload differed by sex.

Electrophysiological characteristics of non-pulmonary vein triggers excluding origins from the superior vena cava and left atrial posterior wall: Lessons from the self-reference mapping technique.

BACKGROUND: The detailed electrophysiological characteristics of atrial fibrillation (AF) initiating non-pulmonary vein (PV) triggers excluding origins from the superior vena cava (SVC) and left atrial posterior wall (LAPW) (Non-PV-SVC-LAPW triggers) remain unclear. This study aimed to clarify the detailed electrophysiological characteristics of non-PV-SVC-LAPW triggers. METHODS: Among 446 AF ablation procedures at 2 institutions, patients with reproducible AF initiating non-PV-SVC-LAPW triggers were retrospectively enrolled. The trigger origin was mapped using the self-reference mapping technique. The following electrophysiological parameters were evaluated: the voltage during sinus rhythm and at the onset of AF at the earliest activation site, coupling interval of the trigger between the prior sinus rhythm and AF trigger, and voltage change ratio defined as the trigger voltage at the onset of AF divided by the sinus voltage. RESULTS: Detailed electrophysiological data were obtained at 28 triggers in 21 patients. The median trigger voltage at the onset of AF was 0.16mV and median trigger coupling interval 182msec. Normal sinus voltages (≧0.5mV) were observed at 16 triggers and low voltages (<0.5mV) at 12 triggers. The voltage change ratio was significantly lower for the normal sinus voltage than low sinus voltage (0.20 vs. 0.60, p = 0.002). The trigger coupling intervals were comparable between the normal sinus voltage and low sinus voltage (170ms vs. 185ms, p = 0.353). CONCLUSIONS: The trigger voltage at the onset of AF was low, regardless of whether the sinus voltage of the trigger was preserved or low.

Clinical Significance of B-Type Natriuretic Peptide Levels at 3 Months after Atrial Fibrillation Ablation.

The role of B-type natriuretic peptide (BNP) levels as a predictor of arrhythmia recurrence (AR) after atrial fibrillation (AF) ablation remains unclear. In this study, we investigated the association of BNP levels before and 3 months after ablation with the risk of AR. A total of 234 patients undergoing their first session of AF ablation were included (68% male, mean age of 69 years). The cut-off value for discriminating AR was determined based on the maximum value of the area under the receiver operating characteristic (ROC) curve. The impact of BNP levels on AR was evaluated using Cox regression analysis. ROC curve analysis showed that the area under the curve for BNP at 3 months after the procedure was larger (0.714) compared to BNP levels before ablation (0.593). Elevated levels of BNP 3 months after the procedure (>40.5 pg/mL, n = 96) was associated with a higher risk of AR compared to those without elevated levels (34.4% vs. 10.9%, p < 0.01). Multivariate Cox regression analysis revealed that elevated BNP levels were associated with an increased risk of AR (hazard ratio 2.43; p = 0.014). Elevated BNP levels 3 months after AF ablation were a significant prognostic factor in AR, while baseline BNP levels were not.

Clinical impact of a self-reference mapping technique to detect non-pulmonary vein triggers: A multi-center study.

BACKGROUND: The method to perform a precise mapping of non-pulmonary vein (PV) triggers has not been fully investigated. The purpose of this study was to assess the efficacy of self-reference mapping for eliminating non-PV triggers in a large series of patients including the long-term outcomes. METHOD: Among 446 atrial fibrillation (AF) ablation procedures in 431 patients at 2 institutions, we prospectively enrolled patients who had reproducible non-PV triggers. Non-PV triggers from the left atrial posterior wall (LAPW) and superior vena cava (SVC) were excluded. Ablation procedure and long-term clinical outcomes were evaluated. The origin of non-PV triggers were detected using a self-reference mapping technique, which does not require any other reference catheters. Instead of using signals obtained from a fixed intracardiac catheter as the reference, an operator repeatedly moved a multi-electrode catheter to the earliest site creating a new reference each time to map the non-PV trigger. RESULTS: A total of 32 non-PV triggers excluding origins from the LAPW and SVC were induced in 23 patients. All triggers were mapped using a self-reference mapping technique with 11.0 ± 10.2 min and eliminated by radiofrequency ablation with 10.7 ± 10.0 points application. No major complications were observed. During the follow-up (529 ± 270 days), 18 patients (77%) were free from atrial tachyarrhythmias after a 3-month blanking period. Three patients received additional ablation procedures. No non-PV triggers ablated during the previous procedure were observed. CONCLUSIONS: A novel self-reference mapping technique is useful for eliminating non-PV triggers for the short- and long-term outcomes.

The utility of atrial overdrive pacing during catheter ablation of premature ventricular contractions originating from the posterior-superior process of the left ventricle.

A 76-year-old man presented with frequent premature ventricular contractions (PVCs). The electrophysiological findings revealed the origin of the PVCs was in the posterior-superior process of the left ventricle (PSP-LV), which is anatomically adjacent to the infero-medial aspect of the right atrium (RA). After a failed ablation from the LV, ablation in the RA eliminated the PVCs. During additional ablation, the atrio-his (AH) interval was monitored by atrial overdrive pacing, and ablation was terminated immediately after the AH interval prolonged to 174 ms. We believe that the atrial overdrive pacing was useful for monitoring the AH interval to prevent atrioventricular block during ablation of PVCs from the PSP-LV. .

Atrial tachycardia related to local abnormal atrial activity.

A 42-year-old woman without a history of catheter ablation or cardiac surgery was referred to our institution for a paroxysmal atrial tachycardia (AT). Programed stimulation could not induce any AT. The AT spontaneously initiated during a continuous isoproterenol infusion. The earliest activation during the AT was recorded at the cavo-tricuspid isthmus, and local abnormal atrial activity (LAATA) was recorded during sinus rhythm at that same site. When rapid atrial activity was recorded at the cavo-tricuspid isthmus where the LAATA was recorded, an AT was induced. Radiofrequency ablation was performed over the entire area where the LAATA was recorded during sinus rhythm, rendering the AT non-inducible.

The usefulness of ventricular pacing during atrial fibrillation ablation in a persistent left superior vena cava: A case report.

A 69-year-old woman with palpitations was referred to our hospital for a second session of atrial fibrillation (AF) catheter ablation. She had a history of AF ablation including pulmonary vein (PV) isolation and persistent left superior vena cava (PLSVC) isolation. Electrophysiologic studies showed the veno-atrial connections that had recovered. After PV isolation was performed, AF was induced by atrial premature contraction (APC) from the PLSVC, and AF storm occurred. During PLSVC isolation, AF was not induced by APC from the PLSVC. PLSVC isolation continued during sinus rhythm. The elimination of the PLSVC potential was difficult to confirm because of the far-field potential of the left ventricle. Then, we performed right ventricular pacing. The remaining PLSVC potential was identified. After that, the PLSVC isolation was successful during right ventricular pacing. Complications were not observed. The patient had no recurrence of AF thereafter.

Unusual Case of Cardiac Amyloidosis Preceded by a Twenty-year History of Dilated Cardiomyopathy and Heart Failure.

Amyloidosis is a well-known but uncommon disease, and the physician must maintain a high index of suspicion in order to make a timely diagnosis. The expected survival of patients with cardiac amyloidosis is generally poor. In particular, survival has been reported to be 4-12 months for patients with amyloid light-chain amyloidosis with congestive heart failure. We herein report a rare case of cardiac amyloidosis in which the patient presented with cardiac hypertrophy after a 20-year history of dilated cardiomyopathy and heart failure.

Effects of alcohol consumption on cardiovascular events in male patients with healed myocardial infarction.

BACKGROUND: In Western countries, many studies have shown that among healthy people moderate drinkers have a lower incidence of cardiovascular events than abstainers and heavy drinkers. However, it is not clear whether this is true in patients with a healed myocardial infarction (MI). METHODS AND RESULTS: In the present study cardiovascular events were defined as cardiac events or strokes. Male patients only were included because the incidence of cardiovascular events is low in females. In patients younger than 65 years, the incidence of cardiovascular events was 34.6 persons per year (54 cases: 3.9%) of abstainers, 17.4 persons per year (20 cases: 1.9%) of moderate drinkers (p<0.01 vs abstainers) and 30.3 s persons per year (18 cases: 3.2%) of heavy drinkers. However, in those aged 65 years or older, the incidence was 47.8 persons per year (24 cases: 4.5%) of abstainers, 58.4 persons per year (14 cases: 5.6%) of moderate drinkers, and 314.8 persons per year (12 cases: 19.7%) of heavy drinkers. In this age group, cardiovascular events were significantly higher in heavy drinkers than in the other 2 groups (p<0.01), and the incidence was not lower in the moderate drinkers than in abstainers as shown in the younger group. CONCLUSIONS: In patients younger than 65 years with a healed MI, drinking limited less than 30 ml/day (moderate intake) reduces the incidence of cardiovascular events, but not in those aged 65 years or older.