Sibling resemblance for left ventricular structure, contractility, and diastolic filling

Area of Science:

• Cardiology
• Genetics
• Hypertension Research

Background:

• Left ventricular (LV) function is known to be genetically influenced.
• The specific contribution of familial factors to LV diastolic filling, contractility, and structure variations remains unclear.

Purpose of the Study:

• To investigate the role of familial factors in the variation and covariation of LV diastolic filling, contractility, and structure.
• To estimate single- and cross-trait sibling correlations for key LV parameters in hypertensive sibships.

Main Methods:

• Bivariate familial correlation models were applied to hypertensive sibling pairs (200 white, 374 black).
• Measured parameters included LV transmitral peak filling velocities, isovolumic relaxation time, atrial filling fraction, stress-corrected midwall shortening, and LV mass/structure.
• Analyses were adjusted for covariates in race-specific linear regression models.

Main Results:

• Single-trait sibling correlation was highest for early peak filling velocity.
• Significant cross-trait correlations were found between early and late peak filling velocities.
• In white participants, correlations were also observed between early peak filling velocity and atrial filling fraction, and between isovolumic relaxation time and end-diastolic posterior wall thickness.

Conclusions:

• Significant cross-trait sibling resemblance suggests pleiotropy or shared environmental influences on LV diastolic parameters and structure.
• These findings are crucial for understanding the heritability of left ventricular diastolic function in hypertensive individuals.