23
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      Techniques for identification of left ventricular asynchrony for cardiac resynchronization therapy in heart failure

      review-article

      Read this article at

      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          The most recent treatment option of medically refractory heart failure includes cardiac resynchronization therapy (CRT) by biventricular pacing in selected patients in NYHA functional class III or IV heart failure. The widely used marker to indicate left ventricular (LV) asynchrony has been the surface ECG, but seems not to be a sufficient marker of the mechanical events within the LV and prediction of clinical response. This review presents an overview of techniques for identification of left ventricular intra- and interventricular asynchrony. Both manuscripts for electrical and mechanical asynchrony are reviewed, partly predicting response to CRT. In summary there is still no gold standard for assessment of LV asynchrony for CRT, but both traditional and new echocardiographic methods have shown asynchronous LV contraction in heart failure patients, and resynchronized LV contraction during CRT and should be implemented as additional methods for selecting patients to CRT.

          Related collections

          Most cited references54

          • Record: found
          • Abstract: found
          • Article: not found

          Recommendations for quantitation of the left ventricle by two-dimensional echocardiography. American Society of Echocardiography Committee on Standards, Subcommittee on Quantitation of Two-Dimensional Echocardiograms.

          We have presented recommendations for the optimum acquisition of quantitative two-dimensional data in the current echocardiographic environment. It is likely that advances in imaging may enhance or supplement these approaches. For example, three-dimensional reconstruction methods may greatly augment the accuracy of volume determination if they become more efficient. The development of three-dimensional methods will depend in turn on vastly improved transthoracic resolution similar to that now obtainable by transesophageal echocardiography. Better resolution will also make the use of more direct methods of measuring myocardial mass practical. For example, if the epicardium were well resolved in the long-axis apical views, the myocardial shell volume could be measured directly by the biplane method of discs rather than extrapolating myocardial thickness from a single short-axis view. At present, it is our opinion that current technology justifies the clinical use of the quantitative two-dimensional methods described in this article. When technically feasible, and if resources permit, we recommend the routine reporting of left ventricular ejection fraction, diastolic volume, mass, and wall motion score.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            Combined cardiac resynchronization and implantable cardioversion defibrillation in advanced chronic heart failure: the MIRACLE ICD Trial.

            Cardiac resynchronization therapy (CRT) through biventricular pacing is an effective treatment for heart failure (HF) with a wide QRS; however, the outcomes of patients requiring CRT and implantable cardioverter defibrillator (ICD) therapy are unknown. To examine the efficacy and safety of combined CRT and ICD therapy in patients with New York Heart Association (NYHA) class III or IV congestive HF despite appropriate medical management. Randomized, double-blind, parallel-controlled trial conducted from October 1, 1999, to August 31, 2001, of 369 patients with left ventricular ejection fraction of 35% or less, QRS duration of 130 ms, at high risk of life-threatening ventricular arrhythmias, and in NYHA class III (n = 328) or IV (n = 41) despite optimized medical treatment. Of 369 randomized patients who received devices with combined CRT and ICD capabilities, 182 were controls (ICD activated, CRT off) and 187 were in the CRT group (ICD activated, CRT on). The primary double-blind study end points were changes between baseline and 6 months in quality of life, functional class, and distance covered during a 6-minute walk. Additional outcome measures included changes in exercise capacity, plasma neurohormones, left ventricular function, and overall HF status. Survival, incidence of ventricular arrhythmias, and rates of hospitalization were also compared. At 6 months, patients assigned to CRT had a greater improvement in median (95% confidence interval) quality of life score (-17.5 [-21 to -14] vs -11.0 [-16 to -7], P =.02) and functional class (-1 [-1 to -1] vs 0 [-1 to 0], P =.007) than controls but were no different in the change in distance walked in 6 minutes (55 m [44-79] vs 53 m [43-75], P =.36). Peak oxygen consumption increased by 1.1 mL/kg per minute (0.7-1.6) in the CRT group vs 0.1 mL/kg per minute (-0.1 to 0.8) in controls (P =.04), although treadmill exercise duration increased by 56 seconds (30-79) in the CRT group and decreased by 11 seconds (-55 to 12) in controls (P<.001). No significant differences were observed in changes in left ventricular size or function, overall HF status, survival, and rates of hospitalization. No proarrhythmia was observed and arrhythmia termination capabilities were not impaired. Cardiac resynchronization improved quality of life, functional status, and exercise capacity in patients with moderate to severe HF, a wide QRS interval, and life-threatening arrhythmias. These improvements occurred in the context of underlying appropriate medical management without proarrhythmia or compromised ICD function.
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              Left bundle-branch block is associated with increased 1-year sudden and total mortality rate in 5517 outpatients with congestive heart failure: a report from the Italian network on congestive heart failure.

              A deleterious effect of complete left bundle-branch block (LBBB) on left ventricular function has been established. Nevertheless, the independent effect of a widened QRS on mortality rate in congestive heart failure (CHF) is still controversial. Therefore, we carried out this analysis to determine whether LBBB is an independent predictor of mortality in CHF. We analyzed the large Italian Network on CHF Registry of unselected outpatients with CHF of different causes. The registry was established by the Italian Association of Hospital Cardiologists in 1995. Complete 1-year follow-up data were available for 5517 patients. The main underlying cardiac diagnosis was ischemic heart disease in 2512 patients (45.6%), dilated cardiomyopathy in 1988 patients (36.0%), and hypertensive heart disease in 714 patients (12.9%). Other causes were recorded in the remaining 303 cases (5.5%). LBBB was present in 1391 patients (25.2%) and was associated with an increased 1-year mortality rate from any cause (hazard ratio, 1.70; 95% confidence interval, 1.41 to 2.05) and sudden death (hazard ratio, 1.58; 95% confidence interval, 1.21 to 2.06). Multivariate analysis showed that such an increased risk was still significant after adjusting for age, underlying cardiac disease, indicators of CHF severity, and prescription of angiotensin-converting enzyme inhibitors and beta-blockers. LBBB is an unfavorable prognostic marker in patients with CHF. The negative effect is independent of age, CHF severity, and drug prescriptions. These data may support the rationale of randomized trials to verify the effects on mortality rate of ventricular resynchronization with multisite cardiac pacing in patients with CHF and LBBB.
                Bookmark

                Author and article information

                Journal
                Indian Pacing Electrophysiol J
                Indian Pacing Electrophysiol J
                Indian Pacing and Electrophysiology Journal
                Indian Pacing and Electrophysiology Group
                0972-6292
                Jul-Sep 2005
                01 July 2005
                : 5
                : 3
                : 175-185
                Affiliations
                Department of Heart Disease, Haukeland University Hospital, Institute of Medicine, University of Bergen, Bergen, Norway
                Author notes
                Address for correspondence: Peter Schuster, MD, Department of Heart Disease, Haukeland University Hospital, N-5021 Bergen, Norway. E-mail: peter.schuster@ 123456med.uib.no
                Article
                ipej050175-00
                1431591
                16943866
                1e8adce6-945b-4c56-b28c-120ddd2a991c
                Copyright: © 2005 Schuster et al.

                This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

                History
                Categories
                Reviews

                Cardiovascular Medicine
                echocardiography,electrical and mechanical asynchrony,cardiac resynchronization pacemaker therapy

                Comments

                Comment on this article