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Blood pressure and myocardial perfusion in hypertensive patients with and without left ventricular hypertrophy
P A Boström1, P Mansour, H Diemer
1Department of Medicine, Lund University, Malmö, Sweden.
Insights
In hypertensive patients with left ventricular hypertrophy (LVH), reducing blood pressure (BP) too low can worsen myocardial ischemia. BP should not drop below 90 mm Hg in these individuals to prevent adverse cardiovascular events.
Area of Science:
- Cardiology
- Cardiovascular Physiology
- Nuclear Cardiology
Background:
- Hypertension is a major risk factor for cardiovascular disease.
- Left ventricular hypertrophy (LVH) is a common adaptation to chronic hypertension.
- The impact of acute blood pressure reduction on myocardial perfusion in hypertensive patients, especially those with LVH, requires further investigation.
Purpose of the Study:
- To evaluate the effect of acute blood pressure (BP) reduction on myocardial perfusion in hypertensive patients with and without LVH.
- To investigate the relationship between BP changes and myocardial ischemia in these patient groups.
Main Methods:
- 10 hypertensive patients with LVH and 10 without LVH underwent 99TCm-Sestamibi scintigraphy at rest and after pharmacological BP reduction (nifedipine and captopril).
- Myocardial ischemia was quantified by the size of the hypoperfused area (isotope uptake < 70% of maximum).
- LVH was defined by echocardiography (left ventricular mass > 125 g/m2 BSA).
Main Results:
- No significant correlation between resting BP and hypoperfused area size was observed.
- In patients with LVH, significant negative correlations were found between BP reduction and the size of the hypoperfused area (SBP r = -0.58, DBP r = -0.49).
- Patients without LVH showed positive correlations between BP reduction and hypoperfused area size (SBP r = 0.60, DBP r = 0.48), with significant differences between groups (P < 0.01).
Conclusions:
- Acute BP reduction in hypertensive patients with LVH is associated with increased myocardial ischemia.
- This finding suggests a potential mechanism for increased cardiovascular events in hypertensive patients with LVH experiencing low achieved BP.
- Maintaining BP above 90 mm Hg is recommended for hypertensive patients with LVH until further evidence defines optimal treatment goals.
Abstract:
To evaluate the effect of acute blood pressure (BP) changes on the myocardial perfusion in hypertensives, 10 patients with and 10 patients without left ventricular hypertrophy (LVH) were examined with 99TCm-Sestamibi scintigraphy at rest and after acute pharmacological BP reduction using nifedipine and captopril. Signs of LV ischaemia was quantified as the size of the hypoperfused area defined as isotope uptake below 70% of maximum LV uptake, and LVH was defined as ventricular mass (LVM) > 125 g/m2 BSA by use of echocardiography. Not significant relations between BP and size of the hypoperfused area was found at rest. During BP reduction patients with LVH had negative correlations (r = -0.58) between the size of the hypoperfused area and the systolic blood pressure (SBP) and the diastolic blood pressure (DBP) (r = -0.49) while patients without LVH showed positive correlations (SBP r = 0.60, DBP r = 0.48). The differences in correlation coefficients were significant (P < 0.01) for both. Thus, in hypertensives with LVH, ischaemia may develop at low BP providing a possible mechanism for the observed increased risk of cardiovascular events in some hypertensive patients with low achieved BP during follow-up. Until treatment goals are defined on scientific grounds, BP should not be decreased below 90 mm Hg in subjects with LVH.