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Silent ST depression and cardiovascular end-organ damage in newly found, older hypertensives
W F Terpstra1, J F May, A J Smit
1Department of Cardiology/Thoraxcenter, University Hospital Groningen, The Netherlands. w.f.terpstra@castel.nl.
Insights
Silent myocardial ischemia, indicated by ST-segment depression, affects about 12% of older hypertensive patients. Vascular factors, not cardiac factors, primarily influence its occurrence in this group.
Area of Science:
- Cardiology
- Hypertension Research
- Vascular Biology
Background:
- Hypertension contributes to myocardial ischemia through reduced vascular supply and increased cardiac demand.
- Silent myocardial ischemia is a significant concern in untreated hypertensive individuals.
Purpose of the Study:
- To determine the prevalence of ST-segment depression in asymptomatic, previously untreated, older hypertensive patients.
- To analyze the contributing vascular and cardiac factors associated with silent myocardial ischemia in this population.
Main Methods:
- A population survey identified 184 mild hypertensive patients (aged 60-75) without prior treatment.
- Cardiovascular end-organ damage was assessed, including intima-media thickness and arterial plaques via B-mode ultrasound.
- Forty-eight-hour ambulatory Holter monitoring was used to detect episodes of ST-segment depression.
Main Results:
- ST-segment depression, indicative of silent myocardial ischemia, was observed in 21 patients (12%).
- Patients with ST depression exhibited significantly higher intima-media thickness and more arterial plaques compared to those without.
- Left ventricular mass index did not significantly differ between groups, but a correlation was found between left ventricular mass and ischemic burden in those with ST depression.
Conclusions:
- Approximately 12% of older, untreated hypertensive individuals experience asymptomatic ST-segment depression.
- Vascular factors, such as arterial wall thickening and plaques, appear to be the primary determinants of ST-segment depression occurrence.
- Cardiac factors, specifically left ventricular mass, correlate with the severity of the ischemic burden in these patients.
Abstract:
In hypertension, both reduced vascular supply and increased cardiac demand contribute to the development of (silent) myocardial ischemia. Our aim was to determine the prevalence of ST-segment depression and to analyze contributing factors in asymptomatic, previously untreated, older hypertensives. From a population survey, in 184 patients with mild hypertension (4 times systolic blood pressure >/=160 mm Hg and/or diastolic blood pressure >/=95 mm Hg), 60 to 75 years of age, cardiovascular end-organ damage was measured. Episodes of ST-segment depression were measured by 48-hour ambulatory Holter monitoring and were observed in 21 hypertensives (12%). They showed a significantly higher combined far-wall intima-media thickness of carotid and femoral arteries and more arterial plaques as measured by B-mode ultrasound compared with hypertensives without ST depression (0.00098+/-0.00021 versus 0.00088+/-0.00016 mm and 5.2+/-3.7 versus 3.7+/-2.8 plaques, P<0.05, respectively), whereas left ventricular mass index was not different (111+/-18 versus 104+/-24 g/m(2); P=0.18, respectively). In hypertensives with transient ST-segment depression, a significant relation was found between left ventricular mass and ischemic burden (r=0.51, P=0.02). Approximately 1 of 8 unselected and previously untreated older hypertensives show asymptomatic ST-segment depression, suggestive of silent myocardial ischemia. These data suggest that vascular factors mainly determine the occurrence of ischemic ST-segment depression and cardiac factors determine the ischemic burden in older hypertensives.