Neuromuscular electrical stimulation is feasible in patients with acute heart failure.

AIMS: In acute heart failure (AHF), immobilization is caused because of unstable haemodynamics and dyspnoea, leading to protein wasting. Neuromuscular electrical stimulation (NMES) has been reported to preserve muscle mass and improve functional outcomes in chronic disease. NMES may be effective against protein wasting frequently manifested in patients with AHF; however, whether NMES can be implemented safely without any adverse effect on haemodynamics has remained unknown. This study aimed to examine the feasibility of NMES in patients with AHF. METHODS AND RESULTS: Patients with AHF were randomly assigned to the NMES or control group. The intensity of the NMES group was set at 10-20% maximal voluntary contraction level, whereas the control group was limited at a visible or palpable level of muscle contraction. The sessions were performed 5 days per week since the day after admission. Before the study implementation, we set the feasibility criteria with following items: (i) change in systolic blood pressure (BP) > ±20 mmHg during the first session; (ii) increase in heart rate (HR) > +20 b.p.m. during the first session; (iii) development of sustained ventricular arrhythmia, atrial fibrillation (AF), and paroxysmal supraventricular tachycardia during all sessions; (iv) incidence of new-onset AF during the hospitalization period < 40%; and (v) completion of the planned sessions by >70% of patients. The criteria of feasibility were set as follows; the percentage to fill one of (i)-(iii) was <20% of the total subjects, and both (iv) and (v) were satisfied. A total of 73 patients (median age 72 years, 51 men) who completed the first session were analysed (NMES group, n = 34; control group, n = 39). Systolic BP and HR variations were not significantly different between two groups (systolic BP, P = 0.958; HR, P = 0.665). Changes in BP > ±20 mmHg or HR > +20 b.p.m. were observed in three cases in the NMES group (8.8%) and five in the control group (12.8%). New-onset arrhythmia was not observed during all sessions in both groups. During hospitalization, one patient newly developed AF in the NMES group (2.9%), and one developed AF (2.6%) and two lethal ventricular arrhythmia in the control group. Thirty-one patients in the NMES group (91%) and 33 patients in the control group (84%) completed the planned sessions during hospitalization. This study fulfilled the preset feasibility criteria. CONCLUSIONS: NMES is feasible in patients with AHF from immediately after admission.

Implantable Cardioverter-Defibrillator Therapy in Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy: Predictors of Appropriate Therapy, Outcomes, and Complications.

BACKGROUND: Arrhythmogenic right ventricular dysplasia/cardiomyopathy is characterized by ventricular arrhythmias and sudden cardiac death. Once the diagnosis is established, risk stratification to determine whether implantable cardioverter-defibrillator (ICD) placement is warranted is critical. METHODS AND RESULTS: The cohort included 312 patients (163 men, age at presentation 33.6±13.9 years) with definite arrhythmogenic right ventricular dysplasia/cardiomyopathy who received an ICD. Over 8.8±7.33 years, 186 participants (60%) had appropriate ICD therapy and 58 (19%) had an intervention for ventricular fibrillation/flutter. Ventricular tachycardia at presentation (hazard ratio [HR]: 1.86; 95% confidence interval [CI], 1.38-2.49; P<0.001), inducibility on electrophysiology study (HR: 3.14; 95% CI, 1.95-5.05; P<0.001), male sex (HR: 1.62; 95% CI, 1.20-2.19; P=0.001), inverted T waves in ≥3 precordial leads (HR: 1.66; 95% CI, 1.09-2.52; P=0.018), and premature ventricular contraction count ≥1000/24 hours (HR: 2.30; 95% CI, 1.32-4.00; P=0.003) were predictors of any appropriate ICD therapy. Inducibility at electrophysiology study (HR: 2.28; 95% CI, 1.10-4.70; P=0.025) remained as the only predictor after multivariable analysis. The predictors for ventricular fibrillation/flutter were premature ventricular contraction ≥1000/24 hours (HR: 4.39; 95% CI, 1.32-14.61; P=0.016), syncope (HR: 1.85; 95% CI, 1.10-3.11; P=0.021), aged ≤30 years at presentation (HR: 1.76; 95% CI, 1.04-3.00; P<0.036), and male sex (HR: 1.73; 95% CI, 1.01-2.97; P=0.046). Younger age at presentation (HR: 3.14; 95% CI, 1.32-7.48; P=0.010) and high premature ventricular contraction burden (HR: 4.43; 95% CI, 1.35-14.57; P<0.014) remained as independent predictors of ventricular fibrillation/flutter. Complications occurred in 66 participants (21%), and 64 (21%) had inappropriate ICD interventions. Overall mortality was low at 2%, and 4% underwent heart transplantation. CONCLUSION: These findings represent an important step in identifying predictors of ICD therapy for potentially fatal ventricular fibrillation/flutter and should be considered when developing a risk stratification model for arrhythmogenic right ventricular dysplasia/cardiomyopathy.

Long-term arrhythmia-free survival in patients with severe left ventricular dysfunction and no inducible ventricular tachycardia after myocardial infarction.

BACKGROUND: A negative electrophysiology study (EPS) may delineate a subgroup of patients with severely impaired left ventricular ejection fraction (LVEF) whose care can be safely managed long-term without an implantable cardioverter-defibrillator. METHODS AND RESULTS: Consecutive patients treated with primary percutaneous coronary intervention for ST-segment-elevation myocardial infarction underwent early (median 4 days) LVEF assessment. Patients with LVEF ≤40% underwent EPS. A prophylactic implantable cardioverter-defibrillator was implanted for a positive (inducible monomorphic ventricular tachycardia) but not a negative (no inducible ventricular tachycardia or inducible ventricular fibrillation/flutter) EPS result. Patients who would have become eligible for a late primary prevention implantable cardioverter-defibrillator with LVEF ≤30% or ≤35% with New York Heart Association class II/III heart failure were included and analyzed according to EPS result. Patients with LVEF >40%, ineligible for EPS, were followed up as control subjects (n=1286). The primary end point was survival free of death or arrhythmia (resuscitated cardiac arrest or sustained ventricular tachycardia/ventricular fibrillation). EPS performed in 128 patients with LVEF ≤30% or with LVEF ≤35% and heart failure was negative in 63% (n=80) and positive in 37% (n=48). Implantable-cardioverter defibrillators were implanted in <0.1%, 4%, and 90% of control, EPS-negative, and EPS-positive patients, respectively. The distribution of time to death or arrhythmia was comparable in control patients and EPS-negative patients with LVEF ≤30% or with LVEF ≤35% and heart failure (P=0.738), who both differed significantly from EPS-positive patients (P<0.001). At 3 years, 91.8 ± 3.2%, 93.4 ± 1.0%, and 62.7 ± 7.5% of control, EPS-negative, and EPS-positive patients were free of death or arrhythmia, respectively. CONCLUSIONS: Revascularized patients with ST-segment-elevation myocardial infarction with severely impaired left ventricular function but no inducible ventricular tachycardia have a favorable long-term prognosis without the protection of an implantable cardioverter-defibrillator.

Brain natriuretic peptide for the prediction of sudden cardiac death and ventricular arrhythmias: a meta-analysis.

AIMS: The risk stratification of patients for sudden cardiac death (SCD) remains a challenge. Brain natriuretic peptide (BNP) predicts overall mortality in heart disease but it is unclear how well it predicts SCD. We therefore performed a meta-analysis of studies evaluating the accuracy of BNP to predict SCD and ventricular arrhythmias (VA). METHODS AND RESULTS: Electronic databases and published bibliographies were systematically searched (1984-2008). We found 14 studies that met our inclusion criteria. Six studies (3543 patients) evaluated BNP to predict SCD in patients without implantable cardioverter defibrillators (ICDs) across a wide range of populations. A raised BNP predicted SCD with a relative risk of 3.68 [95% confidence interval (CI) 1.90, 7.14]. Eight studies (1047 patients) evaluated BNP to predict the occurrence of VA in patients with ICDs. A raised BNP predicted the occurrence of VA with a relative risk of 2.54 (95% CI 1.87, 3.44). CONCLUSION: The measurement of BNP has significant value in predicting SCD and VA. However, the benefit of BNP testing in addition to other risk stratification tests is unclear and BNP needs to be evaluated prospectively in combination with other complementary risk stratification tools.

The natural history of asymptomatic ventricular pre-excitation a long-term prospective follow-up study of 184 asymptomatic children.

OBJECTIVES: The aim of this study was to describe the natural history of asymptomatic ventricular pre-excitation in children and to determine predictors of potentially life-threatening arrhythmic events. BACKGROUND: Sudden death can be the first clinical manifestation in asymptomatic children with ventricular pre-excitation, but reduction of its incidence by prophylactic ablation requires the identification of subjects at high risk. METHODS: Between 1995 and 2005 we prospectively collected clinical and electrophysiologic data from 184 children (66% male; median age 10 years; range 8 to 12 years) with asymptomatic ventricular pre-excitation on the electrocardiogram. After electrophysiologic testing, subjects were followed as outpatients taking no medications. The primary end point of the study was the occurrence of arrhythmic events. Predictors of potentially life-threatening arrhythmias were analyzed. RESULTS: Over a median follow-up of 57 months (min/max 32/90 months) after electrophysiologic testing, 133 children (mean age 10 years; range 8 to 12 years) did not experience arrhythmic events, remaining totally asymptomatic, while 51 children had within 20 months (min/max 8/60 months) a first arrhythmic event, which was potentially life-threatening in 19 of them (mean age 10 years; range 10 to 14 years). Life-threatening tachyarrhythmias resulted in cardiac arrest (3 patients), syncope (3 patients), atypical symptoms (8 patients), or minimal symptoms (5 patients). Univariate analysis identified tachyarrhythmia inducibility (p < 0.001), anterograde refractory period of accessory pathways (APERP)