Myocardial Work Index: A Novel Method for Assessment of Myocardial Function in South Asian Recreational Athletes

Abstract

We used a novel noninvasive method based on speckle-tracking echocardiography to evaluate myocardial performance in South Asian recreational athletes who completed a half marathon. Methods Transthoracic echocardiography was performed on 24 recreational athletes 48 hours before they took part in a half marathon (premarathon), within 2 hours of half marathon completion (postmarathon), and 72 hours after completion. Clinical, laboratory, and echocardiographic variables were collected. Speckle-tracking echocardiography was performed in all subjects to characterize myocardial mechanics. Results Mean age of participants was 41.8 ± 7.4 years, and 23 (95.8%) were male. No subject had a prior history of coronary artery disease. Significant changes in pre-and postmarathon values suggested myocardial injury, including an increase in mean brain natriuretic peptide (BNP), an increase in left atrial volume, and an overall reduction in peak left ventricular global longitudinal strain. All subjects had a similar value of global work index, the average myocardial work, premarathon. Global work index did not change in 11 patients (Group 1), and global work index increased in 13 patients (Group 2) immediately postmarathon. Group 2 patients were noted to have higher heart rate, lower end-diastolic and end-systolic volumes, and higher BNP levels, suggesting myocardial stress. Conclusions South Asian athletes completing a half marathon exhibited two different responses to the cardiac stress of the half marathon, as outlined by the use of myocardial work indices, a novel method for assessing cardiac performance.

Myocardial Work Index during Normal Dobutamine Stress Echocardiography

“…Few studies evaluated strain behaviour during exercise stress echocardiography [14] and dobutamine stress echocardiography [15][16][17]. Recently, a novel myocardial work index was investigated in patients during exercise stress echocardiography [18,19,20], and in athletes after a half marathon [21]. Results of our study showed that despite improvement in global strain, all the parameters of myocardial work deteriorated during dobutamine stress echocardiography: global work index, global constructive work, global work e cacy, and global wasted work.…”

“…Results of our study showed that despite improvement in global strain, all the parameters of myocardial work deteriorated during dobutamine stress echocardiography: global work index, global constructive work, global work e cacy, and global wasted work. During normal exercise stress echocardiography, deterioration was found only in global wasted work [19] and global work e cacy [19,21]; the global work index improved [19,21] and global constructive work improved [19], Table 3. Our results show that the cardiac in uence of dobutamine is different from the effect of exercise during stress echocardiography.…”

Myocardial work index during normal dobutamine stress echocardiography

“…Few studies evaluated strain during exercise stress echocardiography 20 and dobutamine stress echocardiography 5 , 17 – 23 . A novel myocardial work index was investigated in patients during exercise stress echocardiography 24 – 26 , and in athletes after a half marathon 27 . During normal exercise stress echocardiography, deterioration was found only in global wasted work 25 and global work efficacy 25 , 27 ; the global work index improved 25 , 27 and global constructive work improved 25 .…”

“…A novel myocardial work index was investigated in patients during exercise stress echocardiography 24 – 26 , and in athletes after a half marathon 27 . During normal exercise stress echocardiography, deterioration was found only in global wasted work 25 and global work efficacy 25 , 27 ; the global work index improved 25 , 27 and global constructive work improved 25 . In one study 26 , myocardial work index parameters were compared in normal versus ischemic response.…”

Myocardial Work by Echocardiography: Principles and Applications in Clinical Practice

“…Moreover, GWE at rest is able to predict functional capacity and pulmonary or hemodynamic congestion measured at peak effort, better than LVEF. Evaluation of MW indices in 24 half-marathon runners before, immediately post, and 72 hours after a marathon confirmed that GWE and GWW do not change significantly after the competition, but an increase in GWI has been observed in a subgroup of athletes with higher BNP values and higher heart rate [ 60 ]. Authors suggested that increased value of GWI post-marathon would reflect an early manifestation of myocardial stress with increased heart rate, which may be a precursor to myocardial fatigue.…”