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Although the beneficial role of cardiac resynchronization therapy (CRT) in selected patients with heart failure is well proven, its effect on the incidence of atrial fibrillation (AF) is unclear. The present study compared the incidence of AF in 36 consecutive patients with chronic heart failure receiving CRT with its incidence in controls matched for age, gender, and left ventricular ejection fraction but not receiving CRT. The findings suggest that patients with CRT had a significantly lower incidence of AF than controls. Further studies to establish the role of CRT in preventing AF and its mechanisms are warranted. [Copyright &y& Elsevier]

Currently, a clear definition of response to cardiac resynchronization therapy (CRT) is still lacking, and clinical and echocardiographic end points are used. It is also unclear whether patients with clinical responses also improve in echocardiographic end points (and vice versa). To better understand and define response to CRT, the relation between improvement in clinical and echocardiographic parameters was evaluated in 144 patients. [Copyright &y& Elsevier]

A new echocardiographic technology, the timing of regional volumetric changes by 3-dimensional echocardiography, was applied to assess intraventricular mechanical synchronicity in 13 patients who had received cardiac resynchronization therapy (CRT). When biventricular pacing was withheld, left ventricular (LV) asynchrony occurred as reflected by these echocardiographic parameters, whereas LV volume increased and the ejection fraction decreased. Further studies are needed to explore whether this novel method can be used to select suitable candidates for CRT and to predict a favorable response. [Copyright &y& Elsevier]

The assessment of systolic dyssynchrony by echocardiography is useful in predicting a favorable response to cardiac resynchronization therapy (CRT). Tissue Doppler velocity and tissue Doppler longitudinal strain have been suggested for this purpose. This study compared parameters of systolic dyssynchrony derived from these 2 imaging modalities for their predictive values of CRT response. Two hundred fifty-six patients from 3 different centers who received CRT were followed for 6 +/- 3 months. Parameters of systolic dyssynchrony based on tissue Doppler velocity and strain imaging were assessed for the prediction of left ventricular (LV) reverse remodeling (reduction of LV end-systolic volume > or =15%). These included time to peak systolic velocity (or peak strain) of 12 LV segments to calculate the SD (Ts-SD or Tepsilon-SD), maximal difference in delay (Ts-Diff or Tepsilon-Diff), and opposite wall delay (Ts-OW or Tepsilon-OW). The septal-to-lateral delay (Ts-Sep-Lat or Tepsilon-Sep-Lat) was also measured. LV reverse remodeling, defined as improvement in end-systolic volume > or =15%, was observed in 141 patients (55%). All 4 tissue velocity parameters predicted LV reverse remodeling, and the areas under the receiver-operating characteristic curves were 0.86, 0.85, 0.84, and 0.79 for Ts-SD, Ts-Diff, Ts-OW, and Ts-Sep-Lat, respectively (all p <0.001). The cut-off values derived from receiver-operating characteristic curve analysis were 33 ms for Ts-SD, 100 ms for Ts-Diff, 90 ms for Ts-OW, and 60 ms for Ts-Sep-Lat, and their sensitivities were 93%, 92%, 81%, and 70%, with specificities of 78%, 68%, 80%, and 76%, respectively. In contrast, none of the longitudinal strain parameters predicted LV reverse remodeling. The areas under the receiver-operating characteristic curves ranged from 0.49 to 0.53 (all p = NS). The same conclusions were obtained in subgroup analyses of QRS duration (120 to 150 vs >150 ms) and ischemic or nonischemic cause of heart failure. In conclusion, parameters of tissue Doppler longitudinal velocity, but not longitudinal strain, predicted LV reverse remodeling after CRT. [ABSTRACT FROM AUTHOR]

The assessment of systolic dyssynchrony by echocardiography is useful in predicting a favorable response to cardiac resynchronization therapy (CRT). Tissue Doppler velocity and tissue Doppler longitudinal strain have been suggested for this purpose. This study compared parameters of systolic dyssynchrony derived from these 2 imaging modalities for their predictive values of CRT response. Two hundred fifty-six patients from 3 different centers who received CRT were followed for 6 ± 3 months. Parameters of systolic dyssynchrony based on tissue Doppler velocity and strain imaging were assessed for the prediction of left ventricular (LV) reverse remodeling (reduction of LV end-systolic volume ≥15%). These included time to peak systolic velocity (or peak strain) of 12 LV segments to calculate the SD (Ts-SD or Tε-SD), maximal difference in delay (Ts-Diff or Tε-Diff), and opposite wall delay (Ts-OW or Tε-OW). The septal-to-lateral delay (Ts-Sep-Lat or Tε-Sep-Lat) was also measured. LV reverse remodeling, defined as improvement in end-systolic volume ≥15%, was observed in 141 patients (55%). All 4 tissue velocity parameters predicted LV reverse remodeling, and the areas under the receiver-operating characteristic curves were 0.86, 0.85, 0.84, and 0.79 for Ts-SD, Ts-Diff, Ts-OW, and Ts-Sep-Lat, respectively (all p <0.001). The cut-off values derived from receiver-operating characteristic curve analysis were 33 ms for Ts-SD, 100 ms for Ts-Diff, 90 ms for Ts-OW, and 60 ms for Ts-Sep-Lat, and their sensitivities were 93%, 92%, 81%, and 70%, with specificities of 78%, 68%, 80%, and 76%, respectively. In contrast, none of the longitudinal strain parameters predicted LV reverse remodeling. The areas under the receiver-operating characteristic curves ranged from 0.49 to 0.53 (all p = NS). The same conclusions were obtained in subgroup analyses of QRS duration (120 to 150 vs >150 ms) and ischemic or nonischemic cause of heart failure. In conclusion, parameters of tissue Doppler longitudinal velocity, but not longitudinal strain, predicted LV reverse remodeling after CRT. [Copyright &y& Elsevier]

Cardiac resynchronization therapy (CRT) has been shown to reduce symptoms and reverse left ventricular (LV) remodeling. It is not known, however, whether diastolic function will improve after CRT and diastolic asynchrony will predict LV reverse remodeling. Seventy-six patients (mean age 65 ± 12 years, 74% men) who received CRT were studied at baseline and after 3 months. Diastolic function was assessed by transmitral Doppler and tissue Doppler imaging. LV systolic and diastolic asynchrony were assessed by the time to peak myocardial contraction (Ts) and early diastolic relaxation (Te) using the 6 basal, 6 mid-segmental model. There were 42 responders (55%) with LV reverse remodeling (defined as a reduction of LV end-systolic volume ≥15%). Parameters of systolic function were significantly improved only in the responders. For diastolic function, there were reductions of transmitral E velocity in the 2 groups, without any change in atrial velocity or the E/A ratio. Tissue Doppler imaging revealed that myocardial early diastolic velocity was unchanged in responders but was significantly worsened in nonresponders. The systolic asynchrony index (the SD of Ts of 12 LV segments) correlated significantly with LV reverse remodeling (r = −0.64, p <0.001) but not the diastolic asynchrony index (the SD of Te of 12 LV segments) (r = −0.10, p = NS). The systolic asynchrony index was the only independent predictor of reverse remodeling (β = −0.99, 95% confidence interval −1.41 to −0.58, p <0.001). In conclusion, CRT improves systolic function and systolic asynchrony but has a neutral effect on diastolic function and diastolic asynchrony. LV reverse remodeling response is determined by the severity of prepacing systolic asynchrony but not diastolic asynchrony or the diastolic filling pattern. [Copyright &y& Elsevier]