Assessment of papillary muscle free strain in hypertrophic cardiomyopathy and hypertension-induced left ventricular hypertrophy.

Objectives: We aimed to evaluate and compare papillary muscle free strain in hypertrophic cardiomyopathy (HCMP) and hypertensive (HT) patients.

Methods: Global longitudinal strain (GLS), and longitudinal myocardial strain of the anterolateral (ALPM) and posteromedial papillary muscles (PMPM) were obtained in 46 HCMP and 50 HT patients.

Results: Interventricular septum (IVS)/posterior wall (PW) thickness ratio, left ventricular mass index (LVMI), left atrial anteroposterior diameter (LAAP) and mitral E/E' were found to be increased in patients with HCMP compared to HT patients. Left ventricular cavity dimensions were smaller in HCMP patients. GLS of HCMP and HT patients were - 14.52 ± 3.01 and -16.85 ± 1.36%, respectively (p < 0.001). Likewise, ALPM and PMPM free strain values were significantly reduced in HCMP patients over HT patients [-14.00% (-22 to -11%) and -15.5% (-24.02 to -10.16%) vs -23.00% (-24.99 to -19.01%) and -22.30% (-26.48 to -15.95%) (p = 0.016 and p = 0.010)], respectively. ALPM free strain showed a statistically significant correlation with GLS, maximal wall thickness, IVS thickness and LVMI. PMPM free strain showed a significant correlation with GLS, IVS thickness and LAAP. The GLS value of - 13.05 had a sensitivity of 61.9% and a specificity of 97.4% for predicting HCMP. ALPM and PMPM free strain values of -15.31 and -17.17% had 63 and 76.9% sensitivity and 85.7 and 76.9% specificity for prediction of HCMP.

Conclusions: Besides other echocardiographic variables, which were investigated in earlier studies, papillary muscle free strain also could be used in HCMP to distinguish HCMP- from HT-associated hypertrophy.