Effect of remote ischemic postconditioning on left ventricular mechanics

Area of Science:

• Cardiology
• Physiology
• Echocardiography

Background:

• Remote ischemic postconditioning (RIPC) is known to reduce infarct size and prevent left ventricular (LV) remodeling in myocardial infarction patients.
• Previous studies have not investigated the impact of RIPC on LV mechanics using speckle tracking echocardiography.
• This study aimed to assess RIPC's effects on LV deformation parameters like strain, strain rate, rotation, and twist in healthy subjects.

Purpose of the Study:

• To evaluate the impact of remote ischemic postconditioning (RIPC) on left ventricular (LV) mechanics in healthy individuals.
• To investigate changes in LV deformation parameters, including strain, strain rate, rotation, and twist, following RIPC.
• To determine if RIPC influences longitudinal or rotational mechanics of the heart.

Main Methods:

• Twenty-two healthy subjects underwent RIPC, involving three cycles of reperfusion and ischemia after 20 minutes of nondominant arm ischemia.
• Transthoracic echocardiography (TTE) was performed at baseline and 30 minutes post-RIPC.
• LV deformation parameters, including longitudinal strain, circumferential strain, strain rate, basal and apical rotation, and LV twist, were measured using speckle tracking echocardiography.

Main Results:

• Basal circumferential strain significantly decreased post-RIPC (-23 ± 3.4 vs. -18.9 ± 6.9, P = 0.017).
• Apical rotation significantly increased (11.6 ± 3.7 vs. 16.7 ± 4.0, P < 0.001), while basal rotation decreased (-6.1 ± 2.1 vs. -4.7 ± 2.4, P = 0.03).
• Net LV twist significantly increased post-RIPC (17.4 ± 4.5 vs. 21.7 ± 4.7).

Conclusions:

• Remote ischemic postconditioning (RIPC) appears to primarily affect the rotational mechanics of the left ventricle, rather than longitudinal mechanics.
• These findings suggest that RIPC's beneficial effects may be related to alterations in cardiac rotational dynamics.
• The study provides new insights into the mechanisms underlying the favorable effects of postconditioning.