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Evidence for a role for the cardiovascular amplifiers in human primary hypertension
G Jennings1, P I Korner, K Sudhir
1Alfred and Baker Medical Unit, Alfred Hospital, Prahran, Victoria, Australia.
Insights
Primary hypertension involves vascular and cardiac smooth muscle hypertrophy, which contributes to maintaining high blood pressure. Antihypertensive therapy can reverse these structural changes, influencing hypertension recurrence.
Area of Science:
- Cardiology
- Vascular Biology
- Hypertension Research
Background:
- Primary hypertension is characterized by vascular and cardiac smooth muscle hypertrophy.
- These structural changes, particularly hypertrophy, are implicated in maintaining elevated blood pressure through amplifier properties.
Purpose of the Study:
- To investigate the role of smooth muscle hypertrophy in primary hypertension.
- To assess the impact of antihypertensive drug therapy on structural changes in hypertension.
- To explore the relationship between cardiac output, left ventricular hypertrophy regression, and hypertension recurrence.
Main Methods:
- Assessment of non-autonomic vascular resistance and left ventricular mass.
- Evaluation of structural changes following long-term antihypertensive drug therapy.
- Analysis of hypertension redevelopment rate in relation to cardiac output and left ventricular hypertrophy reversal.
Main Results:
- Long-term antihypertensive therapy significantly regresses vascular resistance and left ventricular mass, though the latter occurs more slowly.
- More complete regression of left ventricular hypertrophy is associated with slower hypertension redevelopment after therapy cessation.
- Rapid hypertension recurrence correlates with higher cardiac output, suggesting a role for the cardiac amplifier.
- Primary hypertension may involve generalized vascular smooth muscle dysfunction independent of blood pressure effects.
Conclusions:
- Smooth muscle hypertrophy in vascular and cardiac tissues is a key feature of primary hypertension.
- Antihypertensive therapy can reverse structural abnormalities, impacting disease progression and recurrence.
- Cardiac and vascular smooth muscle function are critical in the pathogenesis and maintenance of hypertension.
Abstract:
1. Hypertrophy of vascular and cardiac smooth muscle is present in human primary hypertension. The amplifier properties associated with hypertrophy play a major role in maintaining hypertension. 2. Long-term antihypertensive drug therapy causes substantial regression of the structural changes, assessed by the non-autonomic component of vascular resistance, and by left ventricular mass. The latter occurs more slowly. 3. The more complete the reversal of left ventricular hypertrophy, the more slowly hypertension redevelops if long-term antihypertensive therapy is discontinued. 4. Subjects who redevelop hypertension more rapidly tend to have higher cardiac output, suggesting that the cardiac amplifier may play a role in the pathogenesis. 5. Studies of small arteries and of veins from patients with primary hypertension suggest that there may be a general disturbance of vascular smooth muscle function, independent of the mechanical effects of elevated systemic blood pressure.