From the Guidelines
To calculate systolic blood pressure (SBP), you need to use a blood pressure monitor or sphygmomanometer and follow the guidelines outlined in the 2017 American College of Cardiology/American Heart Association hypertension guideline 1.
Importance of Accurate Measurement
Accurate measurement of SBP is crucial for assessing cardiovascular health and determining the presence of hypertension. According to the 2017 guideline, normal adult values for SBP are typically below 120 mmHg, while readings above 130 mmHg may indicate hypertension requiring medical attention 1.
Classification of Blood Pressure
The 2017 guideline classifies blood pressure into several categories, including:
- Normal: average SBP <120 mmHg and average diastolic BP <80 mmHg
- Elevated: average SBP of 120 to 129 mmHg and average diastolic BP <80 mmHg
- Stage 1 hypertension: average SBP of 130 to 139 mmHg or average diastolic BP of 80 to 89 mmHg
- Stage 2 hypertension: average SBP of at least 140 mmHg or average diastolic BP of at least 90 mmHg 1
Measurement Technique
To ensure accurate measurements, it is essential to follow proper technique, including:
- Having the person sit quietly for 5 minutes before measuring
- Placing the cuff around the upper arm at heart level
- Inflating the cuff until the pulse disappears, then slowly releasing the pressure
- Taking at least two readings 1-2 minutes apart and averaging them
- Avoiding caffeine, exercise, and smoking for 30 minutes before measurement 1
Clinical Significance
Accurate measurement and classification of SBP are critical for assessing cardiovascular risk and guiding treatment decisions. The 2017 guideline emphasizes the importance of early detection and management of hypertension to reduce the risk of cardiovascular disease 1.
From the FDA Drug Label
The FDA drug label does not answer the question.
From the Research
Systolic Blood Pressure Measurement
- The systolic blood pressure (SBP) can be measured using various techniques, including auscultatory Korotkoff-based sphygmomanometry and oscillometry 2.
- Automatic oscillometry can be used at home by the patient and is preferred even in clinics, but its accuracy is low and errors of 10-15 mmHg are common 2.
- A more accurate technique for automatic SBP measurement is based on an arm pressure cuff and a finger photoplethysmographic probe, which was found to be significantly more accurate than oscillometry and comparable to the Korotkoff-based technique 2.
Calculation of SBP
- There is no direct formula provided in the studies to calculate SBP, but it can be measured using automated or manual sphygmomanometers 3, 4, 5.
- The measurement of SBP is a mainstay for the diagnosis and follow-up of hypertension, and erroneous measurement by 10 mmHg can lead to unintended reduction of SBP and may adversely affect patients 2.
- The optimal blood pressure target can be achieved with lower risk for hypotension and its adverse events by using a more accurate technique for automatic SBP measurement 2.
Factors Affecting SBP Measurement
- The white coat effect can cause overestimation of blood pressure in some patients, and automated office blood pressure (AOBP) can reduce this effect 3.
- The use of an automated device improves accuracy, reduces digit preference, minimizes observer bias, and facilitates the recording of multiple BP readings 3.
- The choice of antihypertensive drugs can also affect SBP, with diuretics and calcium-blocking drugs being more effective in elderly patients at lowering SBP pressure 6.