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Dimensional correlates of left ventricular dilation in the presence of hypertrophy
Insights
The ventricular thickness to radius ratio (t/r) correlates with systolic pressure in heart disease patients. Lower ejection fractions show reduced t/r to pressure ratios, indicating impaired cardiac function.
Area of Science:
- Cardiology
- Biomedical Engineering
- Physiology
Background:
- Assessing cardiac hypertrophy and function noninvasively is crucial in cardiovascular disease.
- The ventricular thickness divided by radius ratio (t/r) is a potential index for evaluating cardiac pressure-dimension relationships.
- Understanding pressure-hypertrophy relationships is key for diagnosing and managing heart conditions.
Purpose of the Study:
- To investigate the relationship between echocardiographically measured ventricular thickness to radius ratio (t/r) and peak systolic pressure (P) in patients with valvular heart disease and hypertension.
- To determine if the t/r ratio, normalized by systolic pressure, can serve as a sensitive, noninvasive index of cardiac dilation and hypertrophy.
Main Methods:
- Echocardiography was used to measure the ventricular thickness to radius ratio (t/r).
- Angiography determined ejection fractions (EF) in patients with valvular heart disease (EF ≥ 0.6 and EF < 0.6).
- Peak systolic pressure (P) was correlated with the t/r ratio across normal subjects, valvular disease patients, and hypertensive patients.
Main Results:
- In subjects with ejection fractions ≥ 0.6, the t/r ratio was proportional to peak systolic pressure (P), with similar t/r/P values.
- Patients with ejection fractions < 0.6 exhibited significantly lower t/r/P values, suggesting altered pressure-hypertrophy relationships.
- Hypertensive patients and those with aortic stenosis (EF ≥ 0.6) showed comparable t/r/P ratios, indicating normal pressure hypertrophy patterns.
Conclusions:
- The t/r ratio, when correlated with systolic pressure, serves as a sensitive, noninvasive index for assessing cardiac dilation.
- Lower ejection fractions are associated with significantly reduced t/r/P values, highlighting potential diastolic dysfunction or remodeling.
- The t/r/P ratio effectively differentiates between normal pressure-hypertrophy relationships and conditions associated with reduced ejection fraction.
Abstract:
Twelve normal subjects, 50 patients with valvular heart disease, and 14 with hypertension were studied. Those with valvular disease were divided into two groups: 28 with angiographically measured ejection fractions greater than or equal to 0.6 and 22 with ejection fractions less than 0.6. The echocardiographically measured ventricular thickness divided by radius ratio (t/r) was approximately proportional to peak systolic pressure (P) in all groups having ejection fractions greater than or equal to 0.6, so that the t/r divided by P ratios were nearly the same. Patients with ejection fractions less than 0.6 had significantly lower t/r divided by P values. No single component of the t/r divided by P ratio would identify the patients with lower ejection fractions. The t/r divided by P ratios in 14 hypertensive patients were nearly identical to the ratios in six patients with aortic stenosis and ejection fractions greater than or equal to 0.6, indicating that an aortic valve gradient does not cause a grossly abnormal form of pressure hypertrophy. The t/r ratio is thus a double sensitive, noninvasive index of dilation when correlated with systolic pressure.