Author + information
- Received October 16, 2012
- Accepted November 15, 2012
- Published online August 1, 2013.
- Manav Sohal, MBBS∗,†,
- Anoop Shetty, MBChB∗,†,
- Simon Duckett, MD∗,
- Zhong Chen, MBBS∗,
- Eva Sammut, MBBS∗,
- Sana Amraoui, MD‡,
- Gerry Carr-White, MD, PhD†,
- Reza Razavi, MD∗∗ ( and )
- Christopher Aldo Rinaldi, MD∗,†
- ∗Division of Imaging Sciences and Biomedical Engineering, King's College, London, United Kingdom
- †Cardiovascular Directorate, Guy's and St. Thomas' NHS Foundation Trust, London, United Kingdom
- ‡Hôpital Cardiologique du Haut-Lévèque, Université Victor Segalen Bordeaux II, Bordeaux, France
- ↵∗Reprint requests and correspondence:
Prof. Reza Razavi, Division of Imaging Sciences, King's College London, Rayne Institute, Lambeth Wing, St. Thomas' Hospital, London SE1 7EH, United Kingdom.
Objectives Type II activation describes the U-shaped electrical activation of the left ventricle (LV) with a line of block in patients with left bundle branch block (LBBB). We sought to determine if a corresponding pattern of contraction could be identified using cardiac magnetic resonance (CMR) cine imaging and whether this predicted response to cardiac resynchronization therapy (CRT).
Background U-shaped LV electrical activation in LBBB has been shown to predict favorable response to CRT. It is not known if the degree of electromechanical coupling is such that the same is true for LV contraction patterns.
Methods A total of 52 patients (48% ischemic) scheduled for CRT implantation prospectively underwent pre-implantation CMR cine analysis using endocardial contour tracking software to generate time−volume curves and contraction propagation maps. These were analyzed to assess the contraction sequence of the LV. The effect of contraction pattern on CRT response in terms of reverse remodeling (RR) and clinical parameters (New York Heart Association functional class, 6-min walk distance and Heart Failure Questionnaire score) was assessed at 6 months.
Results Two types of contraction pattern were identified; homogenous spread from septum to lateral wall (type I, n = 27) and presence of block with a subsequent U-shaped contraction pattern (type II, n = 25). Rates of RR in those with a type 2 pattern were significantly greater at 6 months (80% vs. 26%, p < 0.001) as was mean increase in 6-min walk distance (126 ± 106 m vs. 55 ± 60 m; p = 0.004).
Conclusions Cine CMR can identify a U-shaped pattern of contraction which predicts increased echocardiographic and clinical response rates to CRT in patients with LBBB.
Drs. Sohal and Shetty have received an educational grant from St. Jude Medical. Dr. Razavi has received investigator-led grant funding from Philips Healthcare. Dr. Rinaldi is a consultant to St. Jude and has received research funding from St. Jude, Medtronic, and Boston Scientific. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- Received October 16, 2012.
- Accepted November 15, 2012.
- American College of Cardiology Foundation