Changes in left ventricular long-axis performance during pregnancy occur earlier than do measures of transverse function.

Abstract-Left ventricular hypertrophy is an independent predictor of cardiovascular morbidity and mortality. However, predictors of cardiac structure and function in youth are not completely understood. On 2 occasions (2.3 years apart), we examined 146 youth aged initially 10 to 19 years (mean age, 14.2Ϯ1.8 years). On the initial visit, hemodynamic function was assessed at rest, during laboratory stress (ie, orthostasis, car-driving simulation, video game, and forehead cold), and in the field (ie, ambulatory blood pressure). Quantitative M-mode echocardiograms were obtained on both visits. On both visits, black compared with white youth had higher resting laboratory systolic blood pressure (PϽ0.02), greater relative wall thickness (PϽ0.003), greater left ventricular mass indexed by either body surface area or height 2.7 (PϽ0.01 for both), and lower midwall fractional shortening ratio (PϽ0.05). Hierarchical stepwise regression analysis indicated that significant independent predictors of follow-up left ventricular mass/height 2.7 were the initial evaluation of left ventricular mass/height 2.7 , body mass index, gender (males more than females), and supine resting total peripheral resistance (final model R 2 ϭ0.53). Left ventricular mass/body surface area was predicted by initial left ventricular mass/body surface area, weight, gender, mean supine resting total peripheral resistance, and systolic pressure response to car-driving simulation (final model R 2 ϭ0.48). Midwall fractional shortening was predicted by initial midwall fractional shortening, race (white more than black), and lower mean supine total peripheral resistance (final model R 2 ϭ0.13). The clinical significance of these findings and their implications for improved prevention of cardiovascular diseases are yet to be determined. (Hypertension. 1999;34:1026-1031.)

Whether positive family history (FH) of essential hypertension (EH) in normotensive youth is associated with increased left ventricular mass (LVM) and hemodynamic, anthropometric, and demographic parameters previously associated with increased LVM in adults is unknown. To examine these issues, 323 healthy youth (mean age, 13.6 +/- 1.3 years), 194 with positive FH of EH (61% African Americans, 39% whites) and 129 with negative FH of EH (33% African Americans, 67% whites) were evaluated. Hemodynamics were measured at rest and during four stressors (ie, postural change, car driving simulation, video game, forehead cold). Echocardiographic-derived measures of LVM were indexed separately to body surface area and height(2.7). Controlling for age and race differences (ie, 74% of African Americans v 47% of whites had positive FH), the positive FH group exhibited greater LVM/height(2.7), LVM/body surface area, higher systolic (SBP) and diastolic blood pressures (DBP), and total peripheral resistance index (TPRI) and lower cardiac index at rest (P < .05 for all). The positive FH group also displayed higher peak SBP or DBP and higher TPRI increases to each stressor and came from lower socioeconomic status backgrounds (P < .05 for all). Regression analyses indicated that FH of EH was not a significant determinant of LVM/height(2.7) after accounting for contributions of gender (greater in men), general adiposity, resting cardiac index and blood pressure (BP), and TPRI responsivity to video game and cold stimulation (P < .05 for all). Thus, greater LVM index in positive FH of EH youth appears in part related to their greater BP and TPRI at rest and during stress.

Individuals with a vestibular-related disorder use a somatosensory-dominant strategy for postural orientation following prolonged inclined stance. The implications for the management of this population are discussed.

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