Background: Patients with isolated left ventricular (LV) noncompaction (IVNC) exhibit a unique form of spheric LV remodeling in which the ventricular walls remain thick and the chamber does not dilate in proportion to the remodeling. This study assessed the systolic myocardial shortening properties of the long axis (LA) and short axis (SA) of the LV as determined from pulsed Doppler tissue imaging in two groups of patients with similar degrees of LV dysfunction and similar LV sphericity: patients with IVNC and patients with idiopathic dilated cardiomyopathy (DCMP).
Methods: Pulsed Doppler tissue imaging was used to record systolic myocardial velocities along the LA and SA of the LV in a group with IVNC (n = 13) and a group with DCMP (n = 13). The groups were matched for mean extent of LV dysfunction and mean sphericity index. In all 26 patients, the systolic myocardial velocity pattern for each axis featured two distinct peaks (SW1 and SW2). These peak velocities and the intervals from the electrocardiographic Q wave to each peak (Q-SW1, Q-SW2) were recorded for each axis, and group means were calculated and statistically compared.
Results: There were no significant differences between the IVNC and DCMP groups with respect to any of the pulsed Doppler tissue imaging variables. Concerning the data for SW1 and SW2, intragroup comparisons revealed no significant differences in either group. In each of the two groups, LA-Q-SW1 was significantly shorter than LA-Q-SW2, SA-Q-SW1, and SA-Q-SW2. Each group's LA-Q-SW2 and SA-Q-SW2 values were also statistically similar.
Conclusion: The results indicate that, given comparable degrees of spheric remodeling and comparable LV dysfunction, patients with IVNC and patients with DCMP show similar contraction properties along the LA and SA of the LV.