Strain rate and tissue tracking imaging in quantitation of left ventricular systolic function in endurance and strength athletes

AIM

The aim of this study was to assess the impact of long-term physical training on left ventricular longitudinal contraction by strain rate analysis and tissue tracking imaging.

METHODS AND RESULTS

The study population comprised 17 male elite endurance and 15 male elite strength athletes and 12 male control subjects of similar age. Tissue Doppler imaging was recorded in the apical views and used for analysis of the longitudinal systolic myocardial velocity, annular diastolic velocities, strain rate and tissue tracking. Left ventricular mass index was significantly increased in both endurance athletes (209+/-40 g/m(2)) and strength athletes (138+/-38 g/m(2)) compared with normal subjects (96+/-20 g/m(2), P<0.001). Tissue tracking score index and mean strain rate of the 16 segments were significantly increased in strength athletes (7.9+/-1.1 mm and -1.4+/-0.3 s(-1), respectively) compared with endurance athletes (7.5+/-0.9 mm and -1.0+/-0.4 s(-1), P<0.01 for both) and normal subjects (7.4+/-1.0 mm and -1.0+/-0.3 s(-1), P<0.01 for both).

CONCLUSION

Despite significant left ventricular hypertrophy and extensive training in elite athletes, we found normal longitudinal left ventricular systolic function, and in strength athletes performing isometric exercise even increased function.

Impact of acute biventricular pacing on left ventricular performance and volumes in patients with severe heart failure. A tissue doppler and three-dimensional echocardiographic study

OBJECTIVES

We used tissue velocity imaging (TVI) and three-dimensional echocardiography to evaluate the effect of acute biventricular pacing on left ventricular (LV) performance and volumes in patients with severe heart failure and bundle branch block.

BACKGROUND

Biventricular pacing causes acute hemodynamic improvement in patients with severe heart failure, and QRS duration has been used as a predictor of improved resynchronization. Tissue velocity has the potential of demonstrating the degree of LV resynchronization and three-dimensional echocardiography enables accurate quantitation of LV volumes and function.

METHODS

TVI and three-dimensional echocardiography were performed during sinus rhythm and biventricular pacing in 25 consecutive patients with severe heart failure.

RESULTS

Biventricular pacing significantly improved the extent of contracting myocardium in synchrony by 15.4% and the duration of contraction synchrony by 17% (p < 0.05 for both). Furthermore, end-diastolic and end-systolic volumes decreased by 7 +/- 4.5% and 13 +/- 6% (p < 0.01) and ejection fraction increased by 22.8 +/- 9% (p < 0.01). Baseline duration of QRS and the preejection period as well as the extent of myocardium with asynchronous contraction measured by TVI predicted pacing efficacy. In multivariate analysis, only the extent of myocardium with asynchronous contraction at the LV base predicted biventricular pacing efficacy.

CONCLUSION

Biventricular pacing improves LV systolic performance and reduces LV volumes during short-term treatment. TVI provides important pathophysiological information on the degree of LV resynchronization and may contribute to improved patient selection.

Three dimensional echocardiography documents haemodynamic improvement by biventricular pacing in patients with severe heart failure

OBJECTIVES

To quantify the short term haemodynamic effects of biventricular pacing in patients with heart failure and left bundle branch block by using three dimensional echocardiography.

DESIGN

Three dimensional echocardiography was performed in 15 consecutive heart failure patients (New York Heart Association functional class III or IV) with an implanted biventricular pacing system. Six minute walk tests were performed to investigate the effect of biventricular pacing on exercise capacity. Data were acquired at sinus rhythm and after short term (2–7 days) biventricular pacing.

RESULTS

Compared with baseline values, biventricular pacing significantly reduced left ventricular end diastolic volume (EDV) by mean (SD) 4.0 (5.1)% (p < 0.01) and end systolic volume (ESV) by 5.6 (6.4)% (p < 0.02). Mitral regurgitant fraction was significantly reduced by 11 (12.1)% (p < 0.003) and forward stroke volume (FSV) increased by 13.9 (18.6)% (p < 0.02). Exercise capacity was significantly improved with biventricular pacing by 48.4 (43.3)% (p < 0.00001). Regression analyses showed that the percentage increase in FSV independently predicted percentage improvement in walking distance (r2 = 0.73, p < 0.0002). Both basal QRS duration and QRS narrowing predicted pacing efficacy, showing a significant correlation with %ΔEDV, %ΔESV, and %ΔFSV.

CONCLUSIONS

In five of 15 consecutive patients with heart failure and left bundle branch block, biventricular pacing induced a more than 15% increase in FSV, which predicted a more than 25% increase in walking distance and was accompanied by an immediate reduction in left ventricular chamber size and mitral regurgitation.