Is rotational mechanics the link between strain and ejection fraction in patients with ventricular hypertrophy?

The reduction of global longitudinal strain (GLS) is an early marker of myocardial dysfunction. However, low GLS values do not provide information about the left ventricular ejection fraction (LVEF) because they can be decreased in patients with both reduced and preserved LVEF.

To analyze the impact of rotational mechanics on the LVEF of patients with left ventricular hypertrophy and myocardial dysfunction.

We analyzed 248 patients with left ventricular hypertrophy, and divided them in two groups. Group 1 (n=104) with normal GLS (≥ 17%), and Group 2 (n=144) with decreased GLS (< 17%) due to myocardial dysfunction. We analyzed a) the rotational model ["twist" when the base and apex of the LV rotate in opposite directions, vs "rigid rotation" when the base and apex rotate in the same direction], and b) the rotational gradient (in degrees), as a result, in the case of twist, of the sum of basal and apical rotations (coded positive), and in the case of rigid rotation as a result of the difference between basal and apical rotations (coded negative).

The 104 patients (Group 1) with normal GLS (≥ 17%), and therefore LVEF ≥ 50%, presented twist as the rotational model. Among the 144 pts (Group 2) with myocardial dysfunction (GLS < 17%), LVEF was < 50% in 34.7%. Twist was present in 83.3% of cases, and the remaining 16.7% exhibited rigid rotation. In this Group 2 of patients with myocardial dysfunction, the rotational gradient showed a good correlation with LVEF (r = 0.73; p < 0.001), such that in patients with twist, the values of the rotational gradient were progressively lower as LVEF decreased, until adopting negative values (pattern of rigid rotation) in those with more severe depression of LVEF as shown in Figure 2.

In patients with LVH and GLS impairment, the reduction of the rotational gradient translates into a deterioration of LVEF, providing additional information in the stratification of patients with myocardial dysfunction.

Figure 1

Figure 2