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Systolic function of the hypertrophied left ventricle
Insights
Left ventricular hypertrophy (LVH) in hypertensive patients presents distinct patterns affecting systolic function. Concentric LVH maintains normal or supernormal function, while eccentric LVH preserves ejection through preload reserve.
Area of Science:
- Cardiology
- Hypertension Research
- Cardiac Physiology
Background:
- Left ventricular hypertrophy (LVH) is a common adaptation to chronic pressure overload in hypertension.
- Understanding the different patterns of LVH and their impact on systolic function is crucial for patient management.
Purpose of the Study:
- To investigate the effects of different patterns of left ventricular hypertrophy (LVH) on systolic function in hypertensive patients.
- To correlate LVH indices with hemodynamic parameters and echocardiographic measures of systolic performance.
Main Methods:
- Echocardiography was used to assess LV mass index (LVMI) and relative wall thickness (h/r ratio) in 61 hypertensive patients.
- Patients were categorized into no LVH, concentric LVH, and eccentric LVH groups based on LVH indices.
- Hemodynamic parameters including cardiac output (CO) and total peripheral resistance (TPR) were analyzed.
Main Results:
- Three patterns of LV adaptation were observed: no LVH, concentric LVH, and eccentric LVH.
- Eccentric LVH was associated with high CO and normal TPR, while concentric LVH showed normal CO and increased TPR.
- Systolic function was preserved in all groups, with enhanced contractility in no LVH and preload reserve in eccentric LVH.
Conclusions:
- Hypertension-induced LVH exhibits diverse adaptive patterns impacting hemodynamics and systolic function.
- Concentric LVH may lead to normal or supernormal systolic function, whereas eccentric LVH preserves ejection through preload mechanisms.
Abstract:
The effects of left ventricular hypertrophy (LVH) on systolic function were studied by echocardiography in 61 hypertensive patients. LV mass index (LVMI) and relative wall thickness (h/r ratio) were used together as LVH indices, and three patterns of LV adaptation to the pressure overload were observed: 13 patients had normal LVMI and h/r ratio (no LVH); 32 patients had increased h/r ratio, with normal or increased LVMI (concentric LVH); 16 patients had increased LVMI and normal h/r ratio (eccentric LVH). Cuff arterial pressure was lower in patients without LVH than in those with LVH, but both LVH indices correlated weakly with systolic, diastolic, and mean blood pressure (r = 0.22 to 0.33). Eccentric LVH showed peculiar hemodynamics, characterized by high cardiac output (CO) and normal total peripheral resistance (TPR), whereas CO was normal and TPR moderately and severely increased in patients without LVH and with concentric LVH, respectively. In the group without LVH, peak systolic stress (PSS) and systolic blood pressure/end-systolic volume index (SBP/Ves) were increased, whereas end-diastolic diameter (EDD), end-systolic stress (ESS), and fractional shortening (FS) were normal; thus, the ejective performance was preserved by increased contractility. The group with concentric LVH had normal PSS, ESS, EDD, and FS and increased SBP/Ves, showing that systolic function was normal or supernormal in the presence of adequate LVH. The group with eccentric LVH had increased PSS, ESS, and EDD, whereas FS and SBP/Ves were both normal; thus, the ejective performance was preserved--in spite of an inadequate LVH and increased afterload--through the action of preload reserve.(ABSTRACT TRUNCATED AT 250 WORDS)