Ambulatory blood pressure monitoring (ABPM) is appropriate to evaluate this patient for white coat hypertension. ABPM is accomplished with a device that typically measures blood pressure every 15 to 20 minutes during the day and every 30 to 60 minutes at night. White coat hypertension is defined as blood pressure readings in the office ≥140/90 mm Hg and out-of-office readings that average <135/85 mm Hg. Prevalence may be as high as 10% to 20% of patients diagnosed with hypertension. This patient's blood pressure measurements have been elevated in the office but normal at home and require further documentation with 24-hour ABPM. If she has normal blood pressure at home, her blood pressure would be classified as white coat hypertension, which does not pose an increased risk of cardiovascular events but does increase her risk of future development of hypertension. Conversely, hypertension documented by ABPM is associated with a higher risk of cardiovascular death compared with hypertension determined in the office or at home. A summary of interpretation of office-based, ABPM, and self-recorded blood pressure readings is shown.
Interpretation of Blood Pressure Readings
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Blood Pressure Category
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Office-Based Readings (mm Hg)
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24-Hour Ambulatory Readings (mm Hg)
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Self-Recorded (mm Hg)
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|---|
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Hypertension (Nonelderly)
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Systolic ≥140 or diastolic ≥90
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≥135/85
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≥135/85
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White Coat Hypertension
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≥140/90
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<135/85
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<135/85
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Masked Hypertension
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<140/90
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>135/85
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>135/85
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Urine testing for fractionated metanephrines is used to evaluate for pheochromocytoma as a secondary cause of hypertension. Pheochromocytoma is generally suspected in patients with the symptom triad of episodic headache, sweating, and tachycardia associated with coincident increases in blood pressure. Similar symptoms may be seen with episodes of anxiety and panic attacks, which occur with increased frequency in patients with depression, as is present in this patient. However, these symptoms are not associated with significant blood pressure elevations when caused by anxiety or panic attacks. Documentation of consistent symptoms with accompanying blood pressure elevations would increase consideration of pheochromocytoma; however, testing for this diagnosis would not be indicated in the absence of this relationship, and further assessment for anxiety and panic attacks would be indicated.
Ambulatory electrocardiography or echocardiography would not be the appropriate next steps given the lack of other cardiovascular examination findings; palpitations are common and a nonspecific finding in possible hypertension.
Plasma aldosterone-plasma renin ratio would not be appropriate given this patient's normal laboratory findings and the lack of a firm diagnosis of hypertension.