The Maximum Diameter of the Left Ventricle May Not Be the Optimum Target for Chest Compression During Cardiopulmonary...

Researchers have assumed that compressing the point beneath which the left ventricle (LV) diameter is maximum (P_max.LV) would improve cardiopulmonary resuscitation outcomes. Defining the midsternum, the currently recommended location for chest compression, as the reference (x = 0), the lateral deviation (x_max.LV) of personalized P_max.LV has become estimable using posteroanterior chest radiography. The authors investigated whether out-of-hospital cardiac arrest (OHCA) patients, whose x_max.LV was closer to the midsternum and thus had their P_max.LV compressed closer during cardiopulmonary resuscitation, showed better chances of return of spontaneous circulation (ROSC) and survival to discharge.

Retrospective, cross-sectional study.

A university hospital.

Adult OHCA patients with available previous posteroanterior chest radiography.

None.

For each clinical outcome, multivariable logistic regression was performed, grouping x_max.LV into tertiles and adjusting the variables selected among the core elements of the Utstein template showing possible differences (p > 0.10) in univariate analysis. Odds ratios were presented as OR (95% confidence interval). Among 268 cases (age 64.4 ± 15.8 y, female 89 [33.2%]), 123 (45.9%) achieved ROSC and 40 (14.9%) survival to discharge. Compared with the third tertile of x_max.LV (59 to ∼101 mm), the first (31 to ∼48 mm) and second (48 to ∼59 mm) tertiles, which had a P_max.LV closer to the midsternum, were negatively associated with ROSC (OR 0.502 [0.262-0.960]; p = 0.037 and OR 0.442 [0.233-0.837]; p = 0.012, respectively) and survival to discharge (OR 0.286 [0.080-1.03]; p = 0.055 and OR 0.046 [0.007-0.308]; p = 0.002, respectively).

OHCA patients with a P_max.LV located closer to the midsternum showed worse chances of ROSC and survival to discharge, which challenges the traditional assumption of identifying P_max.LV as the optimum compression point.