Figure 1.

Segmental Mid-Wall Circumferential Myocardial Strain (Ecc), and Strain Rate in HIV-negative and HIV-positive Participants.

The Ecc is calculated as a Lagrangian strain and defined as the ratio of circumferential myocardial shortening from the initial length. The systolic phase is the time period from zero to the peak Ecc who appears negative. Because it is a measure of shortening better contraction is seen as more negative Ecc values; The diastolic phase is the time period from peak Ecc to the end of the cardiac cycle. While differences can be visually observed, in general the observations made are based on group averages rather than individual comparisons thus limiting the need for presentation of individual patient data.

Figure 1A shows Ecc temporal curves for an HIV-negative (plain) and HIV-positive participant (dotted). Peak systolic Ecc strain is defined as as the maximum negative strain during systole (arrow). In this example peak Ecc is lower for this segment in the HIV-positive compared to the HIV-positive participant. Note: No systematic difference between R-R duration between HIV patients and controls was detected.

Figure 1B shows strain rate temporal curves for an HIV-negative (plain) and HIV-positive participant (dotted). Diastolic strain rate is defined as the maximum positive strain rate during early diastole (SR_E) and late diastole (SR_A). Only the early diastolic strain rate (SR_E) was considered in this analysis. In this case, peak SR_E is lower for this segment in the HIV-positive compared to the HIV-positive participant.