Editorial

Abstract

Increasingly, general cardiologists and heart failure specialists are faced with a growing clinical dilemma. Simply put, can anything beyond pharmacologic therapy be proffered to patients with symptomatic severe left ventricular dysfunction and a normal QRS duration to improve quality of life? 1 Sandhu R. Bahler R.C. Prevalence of QRS prolongation in a community hospital cohort of patients with heart failure and its relation to left ventricular systolic dysfunction. Am J Cardiol. 2004; 93: 244-246 Abstract Full Text Full Text PDF PubMed Scopus (85) Google Scholar , 2 Shenkman H.J. Pampati V. Khandelwal A.K. McKinnon J. Nori D. Kaatz S. Sandberg K.R. McCullough P.A. Congestive heart failure and QRS duration: establishing prognosis study. Chest. 2002; 122: 528-534 Crossref PubMed Scopus (204) Google Scholar To date, cardiac electrophysiologists and implantologists have had little to offer from their device armamentaria in this regard. In this issue of Heart Rhythm, Neelagaru et al 3 Neelagaru S.B. Sanchez J.E. Lau S.K. Greeberg S.M. Raval N.Y. Worley S. Kalman J. Merliss A.D. Krueger S. Wood M. Wish M. Burkhoff D. Nadamanee K. Nonexcitatory, cardiac contractility modulation electrical impulses: feasibility study for advanced heart failure in patients with normal QRS duration. Heart Rhythm. 2006; 3: 1140-1147 Abstract Full Text Full Text PDF PubMed Scopus (60) Google Scholar present a pilot study addressing this large clinical problem with a fascinating new technology—the implantable OPTIMIZER system (IMPULSE Dynamics, Orangeburg, NY, USA). The physiologic rationale for this proposed therapy is intriguing. Prior experimental animal studies have suggested that extracellular electrical signals can enhance transsarcolemmal calcium influx and thus increase peak intracellular calcium levels, with a resulting enhancement of myocardial contractility, 4 Mohri S. Shimizu J. Mika Y. Shemer I. Wang J. Ben-Haim S. Burkhoff D. Electric currents applied during the refractory period enhance contractility and systolic calcium in the ferret heart. Am J Physiol Heart Circ Physiol. 2003; 284: H1119-H11123 PubMed Google Scholar , 5 Morita H. Suzuki G. Haddad W. Mika Y. Tanhehco E.J. Sharov V.G. Goldstein S. Ben-Haim S. Sabbah H.N. Cardiac contractility modulation with nonexcitatory electric signals improves left ventricular function in dogs with chronic heart failure. J Card Fail. 2003; 9: 69-75 Abstract Full Text Full Text PDF PubMed Scopus (50) Google Scholar Hence, the OPTIMIZER system with its prepectoral canister and transvenous leads is designed to deliver high-energy but nonexcitatory electrical signals during the ventricular absolute refractory period to improve global left ventricular performance. Earlier publications of the initial use of this novel technology in small, unblinded, nonrandomized uncontrolled human studies have appeared promising. 6 Pappone C. Augello G. Rosanio S. Vicedomini G. Santinelli V. Romano M. Agricola E. Maggi F. Buchmayr G. Morreti G. Mika Y. Ben-Haim S.A. Wolzt M. Stix G. Schmidinger H. First human chronic experience with cardiac contractility modulation by nonexcitatory electrical currents for treating systolic heart failure: mid-term safety and efficacy results from a multicenter study. J Cardiovasc Electrophysiol. 2004; 15: 418-427 Crossref PubMed Scopus (72) Google Scholar , 7 Stix G. Borggrefe M. Wolpert C. Hindricks G. Kottkamp H. Bocker D. Wichter T. Mika Y. Ben-Haim S. Burkhoff D. Wolzt M. Schmidinger H. Chronic electrical stimulation during the absolute refractory period of the myocardium improves severe heart failure. Eur Heart J. 2004; 25: 626-628 Crossref PubMed Scopus (66) Google Scholar