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Objectives: This study aimed to identify an early marker of functional impairment after an implantable cardioverter-defibrillator (ICD) shock as a predictor of heart failure progression. Background: The ICD population has substantial risk of death due to progressive pump failure. Methods: Near-field (NF) bipolar right ventricular (RV) electrograms (EGMs) during induced ventricular fibrillation (VF) and 10 s after rescue ICD shock were analyzed in 310 patients (mean age 59 ± 14.5 years, 219 men [71%]) with structural heart disease, New York Heart Association functional class I to III, and implanted with a single- or dual-chamber Medtronic (Minneapolis, Minnesota) ICD for primary (245 patients, 79%) or secondary prevention of sudden cardiac arrest. A local injury current (LIC) on NF RV EGM was defined as a deviation of EGM potential ≥1 mV or ≥15% of the preceding R-wave peak-to-peak amplitude. Results: During mean follow-up of 29.3 ± 15.0 months, the combined end point of death or hospitalization due to congestive heart failure (CHF) exacerbation was documented in 40 patients (12.9%, or 5.3% per person-year of follow-up). LIC was observed in 106 patients. In multivariate risk analysis, after adjustment for baseline prognostic factors (ejection fraction, history of atrial fibrillation, diabetes mellitus) and appropriate ICD shocks during follow-up, patients with observed LIC after induced VF rescue ICD shock at ICD implantation were more likely to die or to be hospitalized (hazard ratio: 2.69; 95% confidence interval: 1.41 to 5.14; p = 0.003). Conclusions: Transient LIC on bipolar NF RV EGM after induced VF rescue ICD shock is associated with increased risk of CHF progression, future hospitalizations due to CHF exacerbation, and subsequent heart failure death. [Copyright &y& Elsevier]

Objectives: To determine the short-term effects of cardiac resynchronization therapy (CRT) on measurements of left ventricular (LV) diastolic function in patients with severe heart failure. Background: Cardiac resynchronization therapy improves systolic performance; however, the effects on diastolic function by load-dependent pulsed-wave Doppler transmitral indices has been variable. Methods: Fifty patients with severe heart failure were evaluated by two-dimensional Doppler echocardiography immediately prior to and 4 ± 1 month after CRT. Measurements included LV volumes and ejection fraction (EF), pulsed-wave Doppler (PWD)-derived transmitral filling indices (E- and A-wave velocities, E/A ratio, deceleration time [DT], diastolic filling time [DFT], and isovolumic relaxation time). Tissue Doppler imaging was used for measurements of systolic and diastolic (Em) velocities at four mitral annular sites; mitral E-wave/Em ratio was calculated to estimate LV filling pressure. Color M-mode flow propagation velocities were also obtained. Results: After CRT, LV volumes decreased significantly (p < 0.001) and LVEF increased >5% in 28 of 50 patients (56%) and were accompanied by reduction in PWD mitral E-wave velocity and E/A ratio (both p < 0.01), increased DT and DFT (both p < 0.01), and lower filling pressures (i.e., E-wave/Em septal; p < 0.01). Patients with LVEF response ≤5% after CRT had no significant changes in measurements of diastolic function; LV relaxation (i.e., Em velocities) worsened in this group. Conclusions: In heart failure patients receiving CRT, improvement in LV diastolic function is coupled to the improvement in LV systolic function. [Copyright &y& Elsevier]