Mark Kevin Friedberg


Affiliation: The Hospital for Sick Children
Country: Canada


  1. Hui W, Slorach C, Dragulescu A, Mertens L, Bijnens B, Friedberg M. Mechanisms of right ventricular electromechanical dyssynchrony and mechanical inefficiency in children after repair of tetralogy of fallot. Circ Cardiovasc Imaging. 2014;7:610-8 pubmed publisher
    ..The potential of cardiac resynchronization in appropriate patients requires further study. ..
  2. Burkett D, Slorach C, Patel S, Redington A, Ivy D, Mertens L, et al. Left Ventricular Myocardial Function in Children With Pulmonary Hypertension: Relation to Right Ventricular Performance and Hemodynamics. Circ Cardiovasc Imaging. 2015;8: pubmed publisher
    ..Pediatric PH patients demonstrate reduced LV strain/strain rate, predominantly within the septum, with relationships to invasive hemodynamics, right ventricular strain, and functional PH measures. ..
  3. Friedberg M. Imaging Right-Left Ventricular Interactions. JACC Cardiovasc Imaging. 2018;11:755-771 pubmed publisher
    ..This paper reviews the imaging of ventricular-ventricular interactions in acquired and congenital heart disease, demonstrating their importance in a wide array of conditions. ..
  4. Yim D, Hui W, Larios G, Dragulescu A, Grosse Wortmann L, Bijnens B, et al. Quantification of Right Ventricular Electromechanical Dyssynchrony in Relation to Right Ventricular Function and Clinical Outcomes in Children with Repaired Tetralogy of Fallot. J Am Soc Echocardiogr. 2018;31:822-830 pubmed publisher
    ..The prestretch duration percentage and RV basal lateral-to-midseptal delay were independently associated with RV dysfunction, potentially providing a clinical tool to quantify RV electromechanical dyssynchrony. ..
  5. Bharucha T, Khan R, Mertens L, Friedberg M. Right ventricular mechanical dyssynchrony and asymmetric contraction in hypoplastic heart syndrome are associated with tricuspid regurgitation. J Am Soc Echocardiogr. 2013;26:1214-1220 pubmed publisher
    ..RV mechanical dyssynchrony and inhomogeneous contraction are worse in patients with clinically important TR and HLHS. ..
  6. Okumura K, Humpl T, Dragulescu A, Mertens L, Friedberg M. Longitudinal assessment of right ventricular myocardial strain in relation to transplant-free survival in children with idiopathic pulmonary hypertension. J Am Soc Echocardiogr. 2014;27:1344-51 pubmed publisher
    ..RV global longitudinal strain > -14% predicted transplantation-free survival with 100% sensitivity and 54.5% specificity. RV strain imaging may be useful for serial follow-up and prognostication in children with iPAH. ..
  7. Son J, James A, Fan C, Mertens L, McCrindle B, Manlhiot C, et al. Prognostic Value of Serial Echocardiography in Hypoplastic Left Heart Syndrome. Circ Cardiovasc Imaging. 2018;11:e006983 pubmed publisher
    ..Conventional echocardiographic parameters at presentation and during follow-up are potential markers for transplant-free survival in children with hypoplastic left heart syndrome. ..
  8. Sun M, Ishii R, Okumura K, Krauszman A, Breitling S, Gomez O, et al. Experimental Right Ventricular Hypertension Induces Regional β1-Integrin-Mediated Transduction of Hypertrophic and Profibrotic Right and Left Ventricular Signaling. J Am Heart Assoc. 2018;7: pubmed publisher
    ..Reduced LV fibrosis and preserved global function, despite geometrical and pressure aberrations, suggest a possible elastin-mediated protective mechanism at the septal hinge points. ..
  9. Hui W, Slorach C, Friedberg M. Apical Transverse Motion Is Associated with Interventricular Mechanical Delay and Decreased Left Ventricular Function in Children with Dilated Cardiomyopathy. J Am Soc Echocardiogr. 2018;31:943-950 pubmed publisher
    ..Survival was not statistically different in those with ATM or r-ATM compared with those without ATM or r-ATM. In pediatric DCM, ATM is associated with LV dysfunction, mechanical inefficiency, and interventricular mechanical delay. ..

More Information


  1. Forsha D, Slorach C, Chen C, Sherman A, Mertens L, Barker P, et al. Patterns of Mechanical Inefficiency in Pediatric Dilated Cardiomyopathy and Their Relation to Left Ventricular Function and Clinical Outcomes. J Am Soc Echocardiogr. 2016;29:226-36 pubmed publisher
    ..More severe LV discoordination was associated with increased LV dysfunction and a trend toward death or transplantation. ..
  2. Driessen M, Hui W, Bijnens B, Dragulescu A, Mertens L, Meijboom F, et al. Adverse ventricular-ventricular interactions in right ventricular pressure load: Insights from pediatric pulmonary hypertension versus pulmonary stenosis. Physiol Rep. 2016;4: pubmed publisher
  3. Friedberg M, Schwartz S, Zhang H, Chiu Man C, Manlhiot C, Ilina M, et al. Hemodynamic effects of sustained postoperative cardiac resynchronization therapy in infants after repair of congenital heart disease: Results of a randomized clinical trial. Heart Rhythm. 2017;14:240-247 pubmed publisher
    ..These findings warrant further study of CRT to improve postoperative recovery in infants with electrical dyssynchrony. ..
  4. Friedberg M, Margossian R, Lu M, Mercer Rosa L, Henderson H, Nutting A, et al. Systolic-diastolic functional coupling in healthy children and in those with dilated cardiomyopathy. J Appl Physiol (1985). 2016;120:1301-18 pubmed publisher
    ..3538, P < .001). S:D coupling becomes weaker in DCM with LV remodeling and dysfunction. The S:D coupling ratio may be useful to assess coupling, warranting study in relation to patient outcomes. ..
  5. Nielsen E, Okumura K, Sun M, Hjortdal V, Redington A, Friedberg M. Regional septal hinge-point injury contributes to adverse biventricular interactions in pulmonary hypertension. Physiol Rep. 2017;5: pubmed publisher
    ..This suggests that altered geometry and wall stress lead to adverse RV-LV interactions through the septal hinge-points to induce LV fibrosis and dysfunction. ..
  6. Ramos S, Pieles G, Hui W, Ishii R, Slorach C, Friedberg M. Comprehensive echocardiographic assessment of biventricular function in the rabbit, animal model in cardiovascular research: feasibility and normal values. Int J Cardiovasc Imaging. 2018;34:367-375 pubmed publisher
    ..Apical views and strain imaging have lower feasibility. Normal values of LV and RV functional parameters are with comparable values to human children. Animal cardiovascular research is key to develop new goals in clinical practice. ..
  7. Gomez O, Okumura K, Honjo O, Sun M, Ishii R, Bijens B, et al. HEART RATE REDUCTION IMPROVES BIVENTRICULAR FUNCTION AND INTERACTIONS IN EXPERIMENTAL PULMONARY HYPERTENSION. Am J Physiol Heart Circ Physiol. 2017;:ajpheart.00493.2017 pubmed publisher
    ..To investigate mechanisms of heart rate (HR) reduction on biventricular function and interactions in experimental pulmonary arterial hypertension (PAH)...