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The importance of left ventricular hypertrophy in human hypertension
1Karolinska Institute at Danderyd Hospital, Division of Internal Medicine, Sweden. thomas.kahan@med.ds.sll.se
Insights
Left ventricular hypertrophy (LVH) increases mortality risk. Angiotensin II receptor antagonists (AIIRAs) and ACE inhibitors effectively reduce cardiac hypertrophy, offering improved prognosis beyond blood pressure reduction.
Area of Science:
- Cardiology
- Hypertension Research
- Pharmacology
Background:
- Left ventricular hypertrophy (LVH) is a significant independent risk factor for mortality and cardiovascular events.
- LVH contributes to heart failure, arrhythmias, and reduced coronary flow, exacerbating myocardial ischemia.
- Hypertension is a key driver of LVH and coronary artery atherosclerosis.
Purpose of the Study:
- To highlight the prognostic implications of LVH and the importance of diagnostic tools.
- To investigate the differential effects of antihypertensive drug classes on LVH regression.
- To explore the role of the renin-angiotensin system in cardiac hypertrophy.
Main Methods:
- Electrocardiogram (ECG) and echocardiography for LVH diagnosis and geometry assessment.
- Comparative analysis of antihypertensive drug classes, including ACE inhibitors, AIIRAs, and beta-blockers.
- Evaluation of changes in left ventricular mass in response to different treatments.
Main Results:
- Echocardiography offers higher sensitivity than ECG for LVH detection and provides prognostic geometric information.
- Angiotensin-converting enzyme inhibitors (ACEIs) show greater LVH reduction than other classes, independent of blood pressure.
- Angiotensin II receptor antagonists (AIIRAs) demonstrate comparable efficacy to ACEIs in reducing left ventricular mass.
Conclusions:
- LVH reversal improves patient prognosis, with blood pressure reduction being a key factor.
- The renin-angiotensin system, specifically angiotensin II acting on AT1 receptors, plays a crucial role in cardiac hypertrophy.
- ACEIs and AIIRAs represent promising therapeutic strategies for managing LVH and improving cardiovascular outcomes in hypertensive patients.
Abstract:
Hemodynamic and non-hemodynamic factors contribute to the development of left ventricular hypertrophy (LVH). The presence of LVH is an important independent risk factor for total mortality and for cardiovascular morbidity and mortality. Direct cardiac effects of LVH include an increased risk of developing of congestive heart failure, an increased risk of arrhythmic events, and a reduced coronary flow reserve, promoting myocardial ischemic episodes. In addition, hypertension may promote the development of coronary artery atherosclerosis. The prognostic implications of LVH underscore the importance of diagnostic procedures. The electrocardiogram has a high specificity to identify patients with LVH but the sensitivity is fairly low. Echocardiography provides higher sensitivity and also gives important information, such as the pattern of left ventricular geometry, which is of prognostic importance, and the presence of diastolic dysfunction, which is an early abnormality in the evolution of hypertensive LVH. Reversal of LVH appears to improve prognosis. Reduction of blood pressure is one important component in the regression of LVH. Important quantitative differences exist between drug classes in the reversal of cardiac hypertrophy despite similar antihypertensive effects, suggesting other factors to be of importance in the regression of left ventricular mass. LVH is reduced more by angiotensin-converting enzyme inhibitors than by other antihypertensive drug classes, suggesting an effect on structural myocardial changes beyond that provided by the reduction of blood pressure. Recent data suggest that angiotensin II receptor antagonists (AIIRAs) have quantitatively similar effects on left ventricular mass as do angiotensin-converting enzyme inhibitors. A comparative trial of the AIIRA irbesartan and the beta-blocker atenolol demonstrated that despite similar reductions in blood pressure, the reductions attained in left ventricular mass with irbesartan were progressive and numerically greater than those attained with atenolol. Taken together, these findings provide circumstantial evidence for an important role of angiotensin II acting on angiotensin type 1 (AT1) receptors in the development or maintenance of cardiac hypertrophy. Confirmation of the favorable effects of angiotensin-converting enzyme inhibitors and AIIRAs on left ventricular mass in larger trials, including those assessing cardiovascular morbidity and mortality, will be of major importance in the future treatment of hypertension.