Left atrial myocardial function in either physiological or pathological left ventricular hypertrophy: a two-dimensional speckle strain study.

BACKGROUND: Atrial function is an integral part of cardiac function that is often neglected. The presence of left ventricule hypertrophy (LVH) due to arterial hypertension may impair atrial function. However, it has also been suggested that physical training attenuates the age-associated impairment of diastolic filling. This study investigated whether mechanical dysfunction in the left atrium (LA) is present in patients with either physiological or pathological LVH, using two-dimensional strain rate imaging (2D strain echocardiography; 2DSE). METHODS: Standard echocardiography, exercise stress echo and 2DSE of the left atrium were performed in 40 patients with arterial hypertension, 45 age-matched elite athletes (>40 years) and 25 healthy sedentary controls. Atrial longitudinal strain was performed from the apical views for the basal segments of the LA septum, lateral wall and roof. RESULTS: LV mass index and ejection fraction were comparable between patients with either physiological or pathological LVH. Elite athletes showed increased LV end-diastolic diameter, end-diastolic volume and stroke volume, whereas circumferential end-systolic stress was higher in patients with hypertension. LA diameter and maximum volume were increased but similar between the two groups of patients with LVH. LA active emptying volume and fraction were both higher in patients with hypertension. Conversely, peak systolic myocardial atrial strain was significantly reduced in patients with pathological LVH compared with controls and athletes for all the analysed atrial segments (p<0.0001). Using multivariate analysis, LV end-diastolic volume/body surface area (BSA) (beta coefficient 0.52; p<0.0001) and LV mass (beta = 0.48; p<0.001) in athletes emerged as the only independent determinants of LA lateral wall peak systolic strain. In contrast, in patients with hypertension, an independent negative association of LA lateral wall peak systolic strain with both LV mass (beta = -0.42; p<0.001) and circumferential end-systolic stress (beta = -0.43; p<0.001) was found. In addition, in the overall population of patients with LVH, LA lateral wall systolic strain (beta = 0.49; p<0.0001) was a powerful independent predictor of maximum workload during exercise testing. CONCLUSIONS: 2DSE represents a promising, non-invasive, simple and reproducible technique to assess LA myocardial function in patients with either physiological or pathological LVH. LA myocardial deformation is impaired in patients with hypertension compared with age-matched sedentary controls and elite athletes, and is closely associated with functional capacity during effort.

Prognostic value of intra-left ventricular electromechanical asynchrony in patients with mild hypertrophic cardiomyopathy compared with power athletes.

OBJECTIVES: We sought to assess the indexes of myocardial activation delay, using Doppler myocardial imaging (DMI), as potential diagnostic tools and predictors of cardiac events in patients with hypertrophic cardiomyopathy (HCM) compared with power athletes. BACKGROUND: the distribution and magnitude of left ventricular (LV) hypertrophy are not uniform in patients with HCM, which results in heterogeneity of regional LV systolic function. METHODS: The study population comprised 70 young patients with HCM (mean (SD) age 29.4 (5.9) years) with mild septal hypertrophy (15-19 mm) and 85 age and sex matched athletes with septal thickness >12 mm, followed up for 44.4 (10.8) months. Using pulsed DMI, myocardial peak velocities, systolic time intervals, and myocardial intraventricular and interventricular systolic delays were measured in six different basal myocardial segments. RESULTS: DMI analysis showed in HCM lower myocardial both systolic and early diastolic peak velocities of all the segments. Patients with HCM also showed significant interventricular and intraventricular delay (p<0.0001), whereas athletes showed homogeneous systolic activation of the ventricular walls. During the follow up, seven sudden deaths occurred in the HCM group, while no cardiovascular event was observed in the group of athletes. In patients with HCM, intraventricular delay on DMI was the most powerful independent predictor of sudden cardiac death (p<0.0001). An intraventricular delay >45 ms identified with high sensitivity and specificity patients with HCM at higher risk of ventricular tachycardia and cardiac events (test accuracy 90.6%). CONCLUSIONS: DMI may be a valid supporting tool for the differential diagnosis between HCM and "athlete's heart". In patients with HCM, DMI indexes of intraventricular delay may provide additional information for selecting subgroups of patients with HCM at increased risk of ventricular arrhythmias and sudden cardiac death at follow up. Accordingly, such patients may benefit from early intensive treatment and survey. MINIABSTRACT: Doppler myocardial imaging may represent a valid supporting tool for the differential diagnosis between mild hypertrophic cardiomyopathy (HCM) and "athlete's heart". In patients with HCM, DMI indexes of intraventricular delay may provide additional information for selecting subgroups of patients with HCM at increased risk of ventricular arrhythmias and sudden cardiac death at follow up.