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Ventricular and myocardial function following treatment of hypertension
G P Aurigemma1, D Williams, W H Gaasch
1Division of Cardiology, University of Massachusetts Medical School, Worcester, USA. aurigemg@ummhc.org
Insights
Antihypertensive therapy does not impair left ventricular (LV) function. Improvements in midwall shortening are linked to normalized LV geometry, not just reduced LV mass.
Area of Science:
- Cardiology
- Hypertension Research
- Cardiac Physiology
Background:
- Hypertension often leads to left ventricular (LV) remodeling and dysfunction.
- Previous studies on hypertension treatment focused on overall cardiac function, neglecting detailed myocardial mechanics.
- LV midwall mechanics provide a more direct assessment of myocardial function than endocardial measures.
Purpose of the Study:
- To evaluate left ventricular (LV) contractile function, specifically midwall mechanics, following hypertension treatment.
- To analyze the relationship between changes in LV mass, geometry, and myocardial function after antihypertensive therapy.
Main Methods:
- Assessed LV contractile function using endocardial fractional shortening and LV midwall shortening in 268 hypertensive patients.
- Related shortening indices to end-systolic circumferential stress, considering changes in LV mass and relative wall thickness.
- Followed patients for 1-2 years to observe changes after antihypertensive treatment.
Main Results:
- No significant changes in overall endocardial or midwall shortening were observed in the entire patient group.
- A subgroup of 83 patients showed reduced relative wall thickness and improved midwall shortening.
- Improvements in midwall shortening were significantly correlated with changes in relative wall thickness (r = -0.53, p = 0.0001).
Conclusions:
- Antihypertensive therapy, in general, does not decrease LV chamber or myocardial function.
- Enhanced midwall shortening is more associated with the normalization of LV geometry than with the reduction of LV mass.
- LV midwall mechanics offer valuable insights into myocardial adaptation during hypertension treatment.
Abstract:
This study assesses and evaluates left ventricular (LV) contractile function after treatment of hypertension, with an emphasis on LV midwall mechanics. Although prior studies have assessed cardiac function after hypertension treatment, none has performed an analysis of LV midwall mechanics. The Veterans Affairs Study of monotherapy in hypertension was a study large enough to permit analysis of midwall mechanics across a wide spectrum of mass changes accompanying hypertension treatment. LV chamber function was assessed by computing fractional shortening at the endocardial surface; LV midwall shortening was used to define myocardial function. Both shortening indexes were related to end-systolic circumferential stress in the entire population by partitioning values of mass and relative wall thickness changes. Two hundred sixty-eight patients were studied at baseline and again after a 1- or 2-year period. In the entire group, there was no significant change in circumferential shortening either at the endocardium (38 +/- 8% at baseline vs 37 +/- 7% at follow up, p = 0.29) or in shortening at the midwall (20 +/- 3% vs 20 +/- 3%, p = 0.53). However, 83 patients had a reduction in relative wall thickness and an increase in midwall shortening. The change in midwall shortening was significantly related to changes in relative wall thickness (r = -0.53, p = 0.0001). Thus, reductions in LV mass associated with antihypertensive therapy are generally not accompanied by a decrement in LV chamber or myocardial function. Improvement in midwall shortening is more closely related to normalization of LV geometry than to reduction in LV mass.