(NYHA class, VO and exercise tolerance) and improves. 2 max quality of life. ... w4x Cleland JG, Daubert JC, Erdmann E, Freemantle N, Gras D, Kappenber-.
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Table 2 Current UK, European and North American recommendations for the use of bi-ventricular pacing therapy in symptomatic patients with left ventricular systolic dysfunction w11, 12x NICE
ESC
AHAyACA
Symptoms
NYHA III or IV
NYHA III or IV
NYHA III or IV
Medical management
Optimal pharmacologic management
Optimal pharmacologic management
Optimal pharmacologic management
Left ventricular systolic function
LVEF F35%
LVEF F35%
LVEF F35%
Left ventricular dimension (LV dilatation)
Not required
LVEDD )55 mm LVEDD )30 mmym2 LVEDD )30 mmym (height)
LVEDD )55 mm LVEDD )30 mmym2 LVEDD )30 mmym (height)
Cardiac rhythm
Sinus rhythm
Sinus rhythm
Sinus rhythm
QRS G150 ms
QRS )120 ms
QRS )120 ms
Dysynchrony
QRS 120–149 ms plus echocardiographic evidence of dyssynchrony National Institute for Health and Clinical Excellence (NICE). TA120 Heart failure – cardiac resynchronisation: Guidance. http:yywww.nice.org.ukyguidanceyindex.jsp?actionsdownload&os33962 2007.
in sinus rhythm. Evidence of ventricular dysschrony is required on 12-lead ECG (QRS duration )120 ms) or and echocardiographic evidence of mechanical dysschrony if the QRS duration is 120–149 ms (UK guidance only). The North American and European guidelines also recommend that there is evidence of LV enlargement (LV end diastolic diameter )55 mm) w11, 12x. In these patients, bi-ventricular pacing significantly reduces mortality from progressive heart failure as well as all-cause mortality. It also reduces the number of hospitalisations due to heart failure, improves functional status (NYHA class, VO2 max and exercise tolerance) and improves quality of life. Acknowledgments We are grateful for the help and advice of Dr CJ Plummer, consultant cardiologist, Freeman Hospital, Newcastle upon Tyne in preparing this manuscript. References w1x Dunning J, Prendergast B, Mackway-Jones K. Towards evidence-based medicine in cardiothoracic surgery: best BETS. Interact Cardiovasc Thorac Surg 2003;2:405–409. w2x Bristow MR, Saxon LA, Boehmer J, Krueger S, Kass DA, De Marco T, Carson P, DiCarlo L, DeMets D, White BG, DeVries DW, Feldman AM. Cardiac-resynchronization therapy with or without an implantable defibrillator in advanced chronic heart failure. N Engl J Med 2004; 350:2140–2150. w3x Cazeau S, Leclercq C, Lavergne T, Walker S, Varma C, Linde C, Garrigue S, Kappenberger L, Haywood GA, Santini M, Bailleul C, Daubert JC. Effects of multisite biventricular pacing in patients with heart failure and intraventricular conduction delay. N Engl J Med 2001;344:873–880. w4x Cleland JG, Daubert JC, Erdmann E, Freemantle N, Gras D, Kappenberger L, Tavazzi L. The effect of cardiac resynchronization on morbidity and mortality in heart failure. N Engl J Med 2005;352:1539–1549. w5x Abraham WT, Fisher WG, Smith AL, Delurgio DB, Leon AR, Loh E, Kocovic DZ, Packer M, Clavell AL, Hayes DL, Ellestad M, Trupp RJ, Underwood J, Pickering F, Truex C, McAtee P, Messenger J. Cardiac resynchronization in chronic heart failure. N Engl J Med 2002;346:1845– 1853.
w6x McAlister FA, Ezekowitz J, Hooton N, Vandermeer B, Spooner C, Dryden DM, Page RL, Hlatky MA, Rowe BH. Cardiac resynchronization therapy for patients with left ventricular systolic dysfunction: a systematic review. J Am Med Assoc 2007;297:2502–2514. w7x Rivero-Ayerza M, Theuns DA, Garcia-Garcia HM, Boersma E, Simoons M, Jordaens LJ. Effects of cardiac resynchronization therapy on overall mortality and mode of death: a meta-analysis of randomized controlled trials. Eur Heart J 2006;27:2682–2688. w8x Abdulla J, Haarbo J, Kober L, Torp-Pedersen C. Impact of implantable defibrillators and resynchronization therapy on outcome in patients with left ventricular dysfunction – a meta-analysis. Cardiology 2006; 106:249–255. w9x McAlister FA, Ezekowitz JA, Wiebe N, Rowe B, Spooner C, Crumley E, Hartling L, Klassen T, Abraham W. Systematic review: cardiac resynchronization in patients with symptomatic heart failure. Ann Intern Med 2004;141:381–390. w10x Bradley DJ, Bradley EA, Baughman KL, Berger RD, Calkins H, Goodman SN, Kass DA, Powe NR. Cardiac resynchronization and death from progressive heart failure: a meta-analysis of randomized controlled trials. J Am Med Assoc 2003;289:730–740. w11x Vardas PE, Auricchio A, Blanc JJ, Daubert JC, Drexler H, Ector H, Gasparini M, Linde C, Bello Morgado F, Oto A, Sutton R, Trusz-Gluza M. ESC Guidelines for Cardiac Pacing and Cardiac Resynchronization Therapy. Rev Esp Cardiol 2007;60:1272 e1–1272 e51. w12x Strickberger SA, Conti J, Daoud EG, Havranek E, Mehra MR, Pina IL, Young J, Endorsed by the American College of Cardiology Foundation and the Heart Failure Society of America. Patient selection for cardiac resynchronization therapy: from the council on clinical cardiology subcommittee on electrocardiography and arrhythmias and the quality of care and outcomes research interdisciplinary working group, in collaboration with the heart rhythm society. Circulation 2005;111:2146– 2150. w13x Jarcho JA. Biventricular pacing. N Engl J Med 2006;355:288–294. w14x Beshai JF, Grimm RA, Nagueh SF, Baker JH 2nd, Beau SL, Greenberg SM, Pires LA, Tchou PJ. Cardiac-resynchronization therapy in heart failure with narrow QRS complexes. N Engl J Med 2007;357:2461–2471.
eComment: Does cardiac resynchronisation therapy improve survival and quality of life in patients with end-stage heart failure? Authors: Ioanna Koniari, Cardiothoracic Surgery Department, University Hospital of Patras, 22500 Rion Patras, Greece; Spyridon Gkizas, Efstratios Apostolakis doi:10.1510/icvts.2008.183707A The beneficial impact of cardiac resynchronisation therapy (CRT) on Heart Failure (HF)-related morbidity and further mortality w1x is attributed to the
ARTICLE IN PRESS A.J. Turley et al. / Interactive CardioVascular and Thoracic Surgery 7 (2008) 1141–1147 improvement of AV, inter- and intra- ventricular conduction delays which occur in advance heart failure and desynchronize the mechanical activity of the ventricles, thus affecting their pump performance. It is notable that three major types of myocardial asynergy can occur in heart failure patients. One is a progressive loss of integrity of the myocardial collagen matrix, typical of the familial cardiomyopathies but common to all dilated cardiomyopathies. Disruption of the collagen network by altering the ordinate cellular architecture impairs both the intra-ventricular conduction of the electrical impulses and the coordinated mechanical response of the ventricles. The consequences are both prolongation of the QRS and loss of mechanical efficiency. Another type of ventricular asynergy is intra-ventricular conduction delay, generated by bundle branch blocks which most frequently impair conduction through the left bundle branch. A further type of ventricular asynergy is that of regional wall motion abnormalities typical of ischaemic heart disease. Uncoordinated ventricular contraction alters regional workload and stress. The region of early activation contracts against minimal load, rapid early systolic shortening does not translate into pressure because the rest of the myocardium is still inactive; late-activated regions have to face considerable systolic pre-stretch and are subjected to disproportionate load and stress. Much of the ventricular myocardial work is wasted in powerless activity and in transferring ejection from one portion of the chamber to another. Therefore, this pathology results in a prolongation of the ventricular pre-ejection time, a shortening of the ejection and relaxation times, a reduction of ejection fraction, and an increase in mitral regurgitation w2x. Consequently, CRT attempts to resynchronize the desynchronized ventricular activity by modifying their activation sequence. Of course this cannot entirely compensate for intraventricular desynchronization but it can, at least in some patients, improve the ventricular mechanical efficiency. Thus, dyssynchrony seems to represent a patho-physiological process that directly depresses ventricular function, causes LV remodelling and CHF, and as a consequence independently predicts a higher risk of morbidity and mortality. Therefore, there is no doubt that cardiac remodelling constitutes an important target in the treatment of CHF.
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A positive relationship between reverse ventricular remodelling and outcome has been demonstrated with drugs such as angiotensin-converting enzyme-inhibitors, angiotensin-receptor blockers, and beta-adrenergic blockers, with a parallel improvement in ventricular geometry and function and reduction in morbidity and mortality w3x. On the other side, several noncontrolled studies have demonstrated that CRT reverses LV remodelling, decreases LV end-systolic and end-diastolic volumes, and increases LVEF. These benefits were attributed to CRT, since discontinuation of pacing resulted in loss of improvement in cardiac function w4x. Especially, in CAREHF study, the mean reduction in LV end-systolic volume increased from 18.2% after 3 months to 26% after 18 months of CRT. Similarly, mean LVEF increased from 3.7% at 3 months to 6.9% at 18 months. These observations provide consistent evidence of a large, progressive, and sustained reverse remodelling effect conferred by CRT w5x. References w1x Turley AJ, Raja SG, Salhiyyah K, Nagarajan K. Does cardiac resynchronisation therapy improve survival and quality of life in patients with end-stage heart failure? Interact CardioVasc Thorac Surg 2008;7:1141– 1147. w2x Tavazzi L. Ventricular pacing: a promising new therapeutic strategy in heart failure. For whom? Eur Heart J 2000 Aug;21(15):1211–1214. w3x Daubert JC, Leclercq C, Donal E, Mabo P. Cardiac resynchronization therapy in heart failure. Heart Fail Rev 2006;11:147–154. w4x Duncan A, Wait D, Gibson D, Daubert JC. Left ventricular remodeling and hemodynamic effects of multisite pacing in patients with left systolic dysfunction and activation disturbances in sinus rhythm: Substudy of the MUSTIC trial. Eur Heart J 2003;24:430–441. w5x Cleland JGF, Daubert JC, Erdmann E, Freemantle N, Gras D, Kappenberger L, Tavazzi L. The effect of cardiac resynchronization therapy on morbidity and mortality in heart failure (CARE-HF TRIAL). N Engl J Med 2005;352:1539–1549.
