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The Right Ventricle: A Rags-to-Riches Story
Author’s Accepted Manuscript The Right Ventricle: A Rags to Riches Story Timothy M Maus
www.elsevier.com/locate/buildenv
PII: DOI: Reference:
S1053-0770(17)30578-5 http://dx.doi.org/10.1053/j.jvca.2017.06.036 YJCAN4220
To appear in: Journal of Cardiothoracic and Vascular Anesthesia Cite this article as: Timothy M Maus, The Right Ventricle: A Rags to Riches S t o r y , Journal of Cardiothoracic and Vascular Anesthesia, http://dx.doi.org/10.1053/j.jvca.2017.06.036 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting galley proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Title: The Right Ventricle: A Rags to Riches Story
Corresponding Author Timothy M Maus, M.D. Associate Clinical Professor University of California, San Diego Thornton Hospital 9300 Campus Point Drive #7651 La Jolla, California 92037-7651
TEL: (858) 657-7412 FAX: (858) 657-6436 [email protected]
Institution Sulpizio Cardiovascular Center University of California San Diego La Jolla, California
The Right Ventricle: A Rags To Riches Story Everyone loves a good “rags to riches” story. This notion is glorified and ever present in our pop culture - Rocky Balboa’s climb from working class to fighting for the world heavyweight championship in Rocky, Slumdog Millionaire protagonists’ ascent from the slums of Mumbai to a vindicated millionaire game show winner, and The Pursuit of Happyness where the lead character through determination and perseverance is able to propel from his homeless life to a
career owning a multimillion-dollar brokerage firm. The world of cardiac surgery and echocardiography seem an unlikely place to find a “rags to riches” story, but a building one can be found in the perioperative role of the right ventricle (RV). The right ventricle’s “rags” story begins as historically the right heart was viewed with “benign neglect,” neglected with the thought that the RV simply was not as important as the LV. 1 The right ventricle was identified as being the less muscly conduit that functions solely to move returning circulation to the lungs, and less identified with typical cardiac diseases such as ischemia or valvular dysfunction. Research and knowledge about right heart physiology, mechanisms of right ventricular failure and the effect of perioperative RV dysfunction lagged behind due to the medical community’s primary focus on LV function. Slowly data began to emerge highlighting the right ventricles’ role in multiple clinical arenas including the settings of ischemic disease, valvular disease and cardiomyopathy, demonstrating that RV dysfunction is associated with a worsened survival.2,3 Post MI, right ventricular function is associated with increased all-cause mortality, CV death, sudden death and stroke.4 RV dysfunction may develop in these settings via multiple mechanisms: increased pulmonary venous and arterial pressures yielding increased RV afterload, systemic hypotension leading to decreased perfusion pressure to the right heart, ventricular interdependence from dysfunction of the shared septum or intrinsic disease also occurring in the right heart. Perioperatively this dysfunction has gained recognition as a harbinger for poor outcomes. In an evaluation of 400 consecutive patients presenting for cardiac surgery, Peyrou et al found that multiple transthoracic modalities of evaluating RV function predicted postoperative mortality. 5
This effect appears in the literature among multiple subcategories of cardiac surgery. Precardiopulmonary bypass (CPB) right ventricular dysfunction identified by intraoperative TEE was associated with longer duration of post-op mechanical ventilation, longer ICU and hospital stays, and had a smaller recovery of LV ejection fraction (LVEF) in patients undergoing coronary artery bypass graft surgery (CABG) with severely reduced preoperative LVEF. In the setting of aortic and mitral valvular surgery, TEE assessment of right ventricular function had value in predicting postoperative morbidity and mortality.6 Given the increasing popularity of transcatheter aortic valve replacement (TAVR), the role in RV function continues to be elucidated. Zahaf et al demonstrated that surgical AVR (SAVR) was associated with a worsening in RV function postoperatively whereas no reduction in RV function was identified post-TAVR.7 This finding potentially has implications for surgical planning in symptomatic aortic stenosis patients with preexisting RV dysfunction. Additionally RV dysfunction is a well described contributor to morbidity and mortality in the setting of left ventricular assist device (LVAD) implantation, often complicating management strategies.8 In this issue of the Journal, Chen et al add to the “riches” of the role of the right ventricle perioperatively. The authors report that RV dysfunction identified either pre-CPB or post-CPB is associated with the occurrence of post-operative atrial fibrillation (POAF). Postoperative atrial fibrillation is the most frequent complication after cardiac surgery with an incidence above 2030%, with an affect on the survival, incidences of stroke, heart failure, renal failure and infection.9 Identification of risk factors may lead to appropriate risk reduction strategies for the preemptive prevention in those patients deemed at risk. Numerous factors have been associated with POAF including advanced age, male gender, reduced LVEF, and diastolic
dysfunction as well as left atrial enlargement. While RV dysfunction was identified as a risk factor for new-onset AF in decompensated heart failure patients, Chen et al are the first to describe RV dysfunction identified by intraoperative TEE as a risk factor for the development in the cardiac surgical arena. Interestingly, conventional echocardiographic markers of RV dysfunction such as reduced RV fractional area of change (RVFAC), tricuspid annular plane systolic excursion (TAPSE) were not independently associated with the occurrence of POAF. The use of speckle tracking strain echocardiography in the assessment of right ventricle global longitudinal strain (RVGLS) allowed the identification of an association between RV dysfunction and POAF. Specifically, a value greater than -16.7% preCPB and -16.1% postCPB was identified as the cutoff for increased risk of POAF. The use of speckle tracking strain in evaluating right ventricular function has distinct advantages. The right ventricle is a notoriously difficult chamber to evaluate with transesophageal echocardiography. The RV shape is complex and does not assume an approximate geometric shape; the chamber appears triangular in the midesophageal four chamber view yet crescentic in shape in the transgastric midpapillary short axis view, and further yet has a wrap-around appearance in the mid-esophageal RV inflow-outflow view. Additionally the motion of the RV is often oblique to the echo beam rendering Doppler based measurements inaccurate. Speckle tracking, instead of being a Doppler based measurement, identifies speckles or unique echo “thumbprints” and tracks their motion throughout the cardiac cycle, thereby removing the angle dependency. By utilizing the movement of two speckles from frame to frame, strain can quantify the percentage change between the distances of the two speckles from the original distance. Right ventricular global longitudinal
strain measures several sets of speckles in the midesophageal four chamber view from the medial tricuspid annulus along the interventricular septum to the apex and then along the RV free wall to the lateral tricuspid annulus, compiling an aggregate strain value. Better RV function is identified by more negative numbers (i.e. larger absolute values). RVGLS is providing a single value to a global estimate of RV function and in Chen et al’s study as well as others was shown to correlate well with conventional measurements of RV function. While strain imaging is an up and coming technique with continued identified perioperative use, guidelines still suggest further research is necessary.10 Potential disadvantages of strain include it is often an offline or off-cart measurement potentially reducing its perioperative usefulness and values are not vendor interchangeable preventing global application. Future applications of strain imaging in the RV involve the use of RV 3D strain.11 As mentioned previously, the RV is a largely asymmetric chamber and RVGLS from the midesophageal four chamber view aims to provide a global measurement of RV function; however portions of the RV such as the outflow tract are not visualized. RV 3D Strain has the ability to combine three dimensional echocardiography with speckle tracking strain to provide a potentially truer global assessment of RV function. As the medical community has recognized the perioperative importance of RV function in conjunction with echocardiographic and technological advancements, we will continue to see the “rags to riches” story of the perioperative role of the RV unfold.
References 1.
Voelkel NF, Gomez-Arroyo J, Abbate A, Bogaard HJ. Mechanisms of right heart failure-A work in progress and a plea for failure prevention. Pulm Circ. 2013;3(1):137-143.
2.
Galli E, Guirette Y, Feneon D, et al. Prevalence and prognostic value of right ventricular dysfunction in severe aortic stenosis. Eur Heart J Cardiovasc Imaging. 2015;16(5):531538.
3.
Kaul TK, Fields BL. Postoperative acute refractory right ventricular failure: incidence, pathogenesis, management and prognosis. Cardiovasc Surg. 2000;8(1):1-9.
4.
Anavekar NS, Skali H, Bourgoun M, et al. Usefulness of right ventricular fractional area change to predict death, heart failure, and stroke following myocardial infarction (from the VALIANT ECHO Study). Am J Cardiol. 2008;101(5):607-612.
5.
Peyrou J, Chauvel C, Pathak A, Simon M, Dehant P, Abergel E. Preoperative right ventricular dysfunction is a strong predictor of 3 years survival after cardiac surgery. Clin Res Cardiol. 2017.
6.
Haddad F, Denault AY, Couture P, et al. Right ventricular myocardial performance index predicts perioperative mortality or circulatory failure in high-risk valvular surgery. J Am Soc Echocardiogr. 2007;20(9):1065-1072.
7.
Zahaf M BS, Bokowski J, Gasil S, Palacios I. Effect of Transcatheter Aortic Valve Replacement on Right Ventricular Systolic Function: Systematic Review and Metaanalyses. J Clin Exp Cardiolog. 2016;7(5):10.
8.
Argiriou M, Kolokotron SM, Sakellaridis T, et al. Right heart failure post left ventricular assist device implantation. J Thorac Dis. 2014;6 Suppl 1:S52-59.
9.
Omae T, Kanmura Y. Management of postoperative atrial fibrillation. J Anesth. 2012;26(3):429-437.
10.
Rudski LG, Lai WW, Afilalo J, et al. Guidelines for the echocardiographic assessment of the right heart in adults: a report from the American Society of Echocardiography endorsed by the European Association of Echocardiography, a registered branch of the European Society of Cardiology, and the Canadian Society of Echocardiography. J Am Soc Echocardiogr. 2010;23(7):685-713; quiz 786-688.
11.
Blanchard DG, DeMaria AN. Right ventricular 3-dimensional strain in pulmonary hypertension: the quest to see the future. J Am Coll Cardiol. 2014;64(1):52-53.
www.elsevier.com/locate/buildenv
PII: DOI: Reference:
S1053-0770(17)30578-5 http://dx.doi.org/10.1053/j.jvca.2017.06.036 YJCAN4220
To appear in: Journal of Cardiothoracic and Vascular Anesthesia Cite this article as: Timothy M Maus, The Right Ventricle: A Rags to Riches S t o r y , Journal of Cardiothoracic and Vascular Anesthesia, http://dx.doi.org/10.1053/j.jvca.2017.06.036 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting galley proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Title: The Right Ventricle: A Rags to Riches Story
Corresponding Author Timothy M Maus, M.D. Associate Clinical Professor University of California, San Diego Thornton Hospital 9300 Campus Point Drive #7651 La Jolla, California 92037-7651
TEL: (858) 657-7412 FAX: (858) 657-6436 [email protected]
Institution Sulpizio Cardiovascular Center University of California San Diego La Jolla, California
The Right Ventricle: A Rags To Riches Story Everyone loves a good “rags to riches” story. This notion is glorified and ever present in our pop culture - Rocky Balboa’s climb from working class to fighting for the world heavyweight championship in Rocky, Slumdog Millionaire protagonists’ ascent from the slums of Mumbai to a vindicated millionaire game show winner, and The Pursuit of Happyness where the lead character through determination and perseverance is able to propel from his homeless life to a
career owning a multimillion-dollar brokerage firm. The world of cardiac surgery and echocardiography seem an unlikely place to find a “rags to riches” story, but a building one can be found in the perioperative role of the right ventricle (RV). The right ventricle’s “rags” story begins as historically the right heart was viewed with “benign neglect,” neglected with the thought that the RV simply was not as important as the LV. 1 The right ventricle was identified as being the less muscly conduit that functions solely to move returning circulation to the lungs, and less identified with typical cardiac diseases such as ischemia or valvular dysfunction. Research and knowledge about right heart physiology, mechanisms of right ventricular failure and the effect of perioperative RV dysfunction lagged behind due to the medical community’s primary focus on LV function. Slowly data began to emerge highlighting the right ventricles’ role in multiple clinical arenas including the settings of ischemic disease, valvular disease and cardiomyopathy, demonstrating that RV dysfunction is associated with a worsened survival.2,3 Post MI, right ventricular function is associated with increased all-cause mortality, CV death, sudden death and stroke.4 RV dysfunction may develop in these settings via multiple mechanisms: increased pulmonary venous and arterial pressures yielding increased RV afterload, systemic hypotension leading to decreased perfusion pressure to the right heart, ventricular interdependence from dysfunction of the shared septum or intrinsic disease also occurring in the right heart. Perioperatively this dysfunction has gained recognition as a harbinger for poor outcomes. In an evaluation of 400 consecutive patients presenting for cardiac surgery, Peyrou et al found that multiple transthoracic modalities of evaluating RV function predicted postoperative mortality. 5
This effect appears in the literature among multiple subcategories of cardiac surgery. Precardiopulmonary bypass (CPB) right ventricular dysfunction identified by intraoperative TEE was associated with longer duration of post-op mechanical ventilation, longer ICU and hospital stays, and had a smaller recovery of LV ejection fraction (LVEF) in patients undergoing coronary artery bypass graft surgery (CABG) with severely reduced preoperative LVEF. In the setting of aortic and mitral valvular surgery, TEE assessment of right ventricular function had value in predicting postoperative morbidity and mortality.6 Given the increasing popularity of transcatheter aortic valve replacement (TAVR), the role in RV function continues to be elucidated. Zahaf et al demonstrated that surgical AVR (SAVR) was associated with a worsening in RV function postoperatively whereas no reduction in RV function was identified post-TAVR.7 This finding potentially has implications for surgical planning in symptomatic aortic stenosis patients with preexisting RV dysfunction. Additionally RV dysfunction is a well described contributor to morbidity and mortality in the setting of left ventricular assist device (LVAD) implantation, often complicating management strategies.8 In this issue of the Journal, Chen et al add to the “riches” of the role of the right ventricle perioperatively. The authors report that RV dysfunction identified either pre-CPB or post-CPB is associated with the occurrence of post-operative atrial fibrillation (POAF). Postoperative atrial fibrillation is the most frequent complication after cardiac surgery with an incidence above 2030%, with an affect on the survival, incidences of stroke, heart failure, renal failure and infection.9 Identification of risk factors may lead to appropriate risk reduction strategies for the preemptive prevention in those patients deemed at risk. Numerous factors have been associated with POAF including advanced age, male gender, reduced LVEF, and diastolic
dysfunction as well as left atrial enlargement. While RV dysfunction was identified as a risk factor for new-onset AF in decompensated heart failure patients, Chen et al are the first to describe RV dysfunction identified by intraoperative TEE as a risk factor for the development in the cardiac surgical arena. Interestingly, conventional echocardiographic markers of RV dysfunction such as reduced RV fractional area of change (RVFAC), tricuspid annular plane systolic excursion (TAPSE) were not independently associated with the occurrence of POAF. The use of speckle tracking strain echocardiography in the assessment of right ventricle global longitudinal strain (RVGLS) allowed the identification of an association between RV dysfunction and POAF. Specifically, a value greater than -16.7% preCPB and -16.1% postCPB was identified as the cutoff for increased risk of POAF. The use of speckle tracking strain in evaluating right ventricular function has distinct advantages. The right ventricle is a notoriously difficult chamber to evaluate with transesophageal echocardiography. The RV shape is complex and does not assume an approximate geometric shape; the chamber appears triangular in the midesophageal four chamber view yet crescentic in shape in the transgastric midpapillary short axis view, and further yet has a wrap-around appearance in the mid-esophageal RV inflow-outflow view. Additionally the motion of the RV is often oblique to the echo beam rendering Doppler based measurements inaccurate. Speckle tracking, instead of being a Doppler based measurement, identifies speckles or unique echo “thumbprints” and tracks their motion throughout the cardiac cycle, thereby removing the angle dependency. By utilizing the movement of two speckles from frame to frame, strain can quantify the percentage change between the distances of the two speckles from the original distance. Right ventricular global longitudinal
strain measures several sets of speckles in the midesophageal four chamber view from the medial tricuspid annulus along the interventricular septum to the apex and then along the RV free wall to the lateral tricuspid annulus, compiling an aggregate strain value. Better RV function is identified by more negative numbers (i.e. larger absolute values). RVGLS is providing a single value to a global estimate of RV function and in Chen et al’s study as well as others was shown to correlate well with conventional measurements of RV function. While strain imaging is an up and coming technique with continued identified perioperative use, guidelines still suggest further research is necessary.10 Potential disadvantages of strain include it is often an offline or off-cart measurement potentially reducing its perioperative usefulness and values are not vendor interchangeable preventing global application. Future applications of strain imaging in the RV involve the use of RV 3D strain.11 As mentioned previously, the RV is a largely asymmetric chamber and RVGLS from the midesophageal four chamber view aims to provide a global measurement of RV function; however portions of the RV such as the outflow tract are not visualized. RV 3D Strain has the ability to combine three dimensional echocardiography with speckle tracking strain to provide a potentially truer global assessment of RV function. As the medical community has recognized the perioperative importance of RV function in conjunction with echocardiographic and technological advancements, we will continue to see the “rags to riches” story of the perioperative role of the RV unfold.
References 1.
Voelkel NF, Gomez-Arroyo J, Abbate A, Bogaard HJ. Mechanisms of right heart failure-A work in progress and a plea for failure prevention. Pulm Circ. 2013;3(1):137-143.
2.
Galli E, Guirette Y, Feneon D, et al. Prevalence and prognostic value of right ventricular dysfunction in severe aortic stenosis. Eur Heart J Cardiovasc Imaging. 2015;16(5):531538.
3.
Kaul TK, Fields BL. Postoperative acute refractory right ventricular failure: incidence, pathogenesis, management and prognosis. Cardiovasc Surg. 2000;8(1):1-9.
4.
Anavekar NS, Skali H, Bourgoun M, et al. Usefulness of right ventricular fractional area change to predict death, heart failure, and stroke following myocardial infarction (from the VALIANT ECHO Study). Am J Cardiol. 2008;101(5):607-612.
5.
Peyrou J, Chauvel C, Pathak A, Simon M, Dehant P, Abergel E. Preoperative right ventricular dysfunction is a strong predictor of 3 years survival after cardiac surgery. Clin Res Cardiol. 2017.
6.
Haddad F, Denault AY, Couture P, et al. Right ventricular myocardial performance index predicts perioperative mortality or circulatory failure in high-risk valvular surgery. J Am Soc Echocardiogr. 2007;20(9):1065-1072.
7.
Zahaf M BS, Bokowski J, Gasil S, Palacios I. Effect of Transcatheter Aortic Valve Replacement on Right Ventricular Systolic Function: Systematic Review and Metaanalyses. J Clin Exp Cardiolog. 2016;7(5):10.
8.
Argiriou M, Kolokotron SM, Sakellaridis T, et al. Right heart failure post left ventricular assist device implantation. J Thorac Dis. 2014;6 Suppl 1:S52-59.
9.
Omae T, Kanmura Y. Management of postoperative atrial fibrillation. J Anesth. 2012;26(3):429-437.
10.
Rudski LG, Lai WW, Afilalo J, et al. Guidelines for the echocardiographic assessment of the right heart in adults: a report from the American Society of Echocardiography endorsed by the European Association of Echocardiography, a registered branch of the European Society of Cardiology, and the Canadian Society of Echocardiography. J Am Soc Echocardiogr. 2010;23(7):685-713; quiz 786-688.
11.
Blanchard DG, DeMaria AN. Right ventricular 3-dimensional strain in pulmonary hypertension: the quest to see the future. J Am Coll Cardiol. 2014;64(1):52-53.