New Methods for Quantifying the Synchrony of Contraction and Relaxation in the Heart
Investigators: Brandon Fornwalt, Takeshi Arita, MD, John Merlino, MD, Angel León, MD, Derek Fyfe, MD, PhD, Patrick Frias, MD,
John Oshinski, PhD
Goal: Develop and evaluate new methods for quantifying dyssynchronous contraction in the heart.
Normal hearts contract in synchrony to optimize function - all the muscle in the ventricles typically contract within a period of about 50 milliseconds. However, approximately 30% of patients with heart failure have a conduction block in the heart which leads to dyssynchronous contraction. The movie below (LEFT) shows a heart with a conduction block that has lead to dyssynchronous contraction. A normal heart is shown on the right for comparison.
Dyssynchrony can be diagnosed using tissue Doppler imaging of the heart. Velocity-time curves from 2 or more regions of the ventricle are compared to determine whether a patient has dyssynchrony. The heart shown below (LEFT) has severe dyssynchrony: the walls of the heart are moving in opposite directions of each other for most of the cardiac cycle. A normal heart is shown on the right for comparison.
We are developing new mathematical techniques to use both MRI and tissue Doppler to diagnose dyssynchrony in a semi-automated fashion. For more information email Brandon Fornwalt or John Oshinski .
- Fornwalt BK, Arita T, Bhasin M, Voulgaris G, Merlino JD, León AR, Fyfe DA, Oshinski JN. Cross-correlation quantification of dyssynchrony: a new method for quantifying the synchrony of contraction and relaxation in the heart. J Am Soc Echocardiogr. 2007; (In press).
- Fornwalt BK, Mahle WT, Fyfe DA. Resynchronization and strain recovery following reimplantation of anomalous coronary artery: a Tissue Doppler and three-dimensional echocardiographic study. Congenit Heart Dis. 2007;2:58-63.
- Fornwalt BK, Cummings RM, Arita T, Fyfe DA, Campbell RM, Strieper MJ, Oshinski JN, Frias PA. Cross-correlation measures of dyssynchrony are superior to current clinical parameters: Validation in structurally normal pediatric hearts. Sep 2006, Southeast Pediatric Cardiology Society, Stone Mountain, GA.
- Delfino JG, Fornwalt BK, Eisner R, León AR, Oshinski JN. Determination of myocardial radial strain and strain rate using MR phase velocity mapping. July 2006, International Soc of Magnetic Res in Med Flow & Motion Workshop, New York, NY.
- Arita T, Sorescu GP, Fornwalt BK, Schuler BT, Whalen P, Schmarkey LS, Vinten-Johansen J, Merlino JD, León AR, Martin RP, Sorescu D. Systolic dyssynchrony is present in heart failure with narrow or wide QRS, while diastolic dyssynchrony is present only in heart failure with wide QRS in a canine model of heart failure. Nov 2006, American Heart Association, Chicago, IL. Circulation. 2006;114(18):S410.
- Arita T, Fornwalt BK, Pernetz MA, Howell S, El-Chami MF, Sorescu D, Lerakis S, Clements SD, Martin RP. Pattern of mechanical dyssynchrony differs in heart failure with narrow and wide QRS. Nov 2006, American Heart Association, Chicago, IL. Circulation. 2006;114(18):S410.
- Alderson TM, Fornwalt BK, Fyfe DA, Mahle WY, Frias PA, Gooden K, Spainhour C, Strieper MJ. Mechanical dyssynchrony in young patients with dilated cardiomyopathy and narrow QRS. May 2006, Heart Rhythm Society Annual Meeting, Boston, MA. Heart Rhythm. 2006;3(5):S80.
- Arita T, Fornwalt BK, Notabartolo D, Pernetz MA, Lerakis S, Clements SD, Sorescu D, Merlino JD, Martin RP, León AR. Novel assessment of cardiac dyssynchrony using variance of dyssynchrony vector on tissue Doppler imaging to predict reverse remodeling. June 2006, American Society of Echocardiography, Baltimore, MD. J Am Soc Echocardiogr. 2006;19(5):619.
- Fornwalt BK, Mahle WT, Fyfe DA. Resynchronization and strain recovery following reimplantation of anomalous coronary: a Tissue Doppler and three-dimensional echocardiographic study. Sep 2004, Southeast Pediatric Cardiology Society, Howey-in-the-hills, FL. Cardiol Young. 2005;15:100.