What does it mean when multiple sounds are heard during a blood pressure check and how is it managed?

Understanding Multiple Sounds During Blood Pressure Measurement

When multiple sounds are heard during blood pressure measurement, this typically indicates arrhythmias, auscultatory gaps, or other cardiovascular conditions that require proper technique and potentially further evaluation.

Types of Multiple Sounds and Their Significance

• Arrhythmias: When the cardiac rhythm is irregular (such as in atrial fibrillation), blood pressure and cardiac output vary significantly from beat to beat, making measurement challenging and potentially inaccurate 1
• Auscultatory Gap: In older patients with wide pulse pressure, Korotkoff sounds may become inaudible between systolic and diastolic pressure and then reappear as cuff deflation continues, often occurring in patients with target organ damage 1
• Third Heart Sound (S3): When detected during blood pressure measurement, this additional "lub-dub-dub" sound often indicates left ventricular dysfunction and may represent heart failure, particularly when accompanied by other signs of cardiac compromise 2
• Multiple Korotkoff Phases: The five phases of Korotkoff sounds may be particularly pronounced or variable in certain patients, causing confusion during measurement 1

Management Approach for Multiple Sounds

For Arrhythmias

• Take multiple measurements (at least 2-3) and use the average value when irregular rhythms are present 1
• Deflate the cuff more slowly than usual if bradycardia is present (40-50 bpm) to prevent underestimation of systolic and overestimation of diastolic pressure 1
• Consider that automated devices are frequently inaccurate for single observations in patients with atrial fibrillation and should be validated individually before use 1
• In some cases, intra-arterial blood pressure measurement may be necessary to establish a baseline for comparison 1

For Auscultatory Gap

• Elevate the arm overhead for 30 seconds before inflating the cuff and then bring the arm to the usual position to continue measurement 1
• This maneuver reduces vascular volume in the limb and improves inflow to enhance the Korotkoff sounds 1
• Ensure proper inflation of the cuff to at least 30 mmHg above the estimated systolic pressure to avoid missing the true systolic pressure 1

For Third Heart Sound (S3)

• When S3 is detected during blood pressure measurement, a complete cardiovascular assessment is warranted, including echocardiography to assess left ventricular function 2
• Note that in young, healthy individuals (especially athletes) and pregnant women, S3 may be a normal finding and not indicative of heart disease 2

General Management Principles

• Use proper technique for blood pressure measurement, including correct cuff size, patient positioning, and deflation rate 1
• Take at least two readings and average them for more accurate assessment 1
• For patients with persistent irregular sounds, consider:
  • Referral for cardiovascular evaluation if clinical suspicion of heart disease exists 2
  • Home blood pressure monitoring with validated devices to obtain multiple readings under standardized conditions 1
  • Ambulatory blood pressure monitoring for 24-hour assessment if white coat hypertension or masked hypertension is suspected 3

Special Considerations

• Obese Patients: Use a longer and wider cuff for adequate compression of the brachial artery, and place the center of the bladder over the brachial artery pulse 1
• Pregnant Women: The International Society for the Study of Hypertension in Pregnancy recommends using K5 (disappearance of sounds) for diastolic blood pressure, but when sounds are audible with the cuff fully deflated, K4 (muffling) should be used 1
• Children: In some children, Korotkoff sounds can be heard down to 0 mmHg, which has limited physiological meaning; multiple measurements over time are recommended 1

Common Pitfalls and How to Avoid Them

• Incorrect cuff size: Using too small a cuff can lead to falsely elevated readings; ensure proper cuff size based on arm circumference 1
• Rapid deflation: Deflating the cuff too quickly can lead to missed or misinterpreted sounds; maintain a deflation rate of 2-3 mmHg per second 1
• Observer bias: Terminal digit preference can affect readings; consider using hybrid or automated devices that display exact values 1
• Equipment issues: Ensure devices are validated and calibrated regularly; 21-50% of devices in hospital settings have been found to have technical problems that limit accuracy 1

By understanding the significance of multiple sounds during blood pressure measurement and following proper technique, clinicians can obtain more accurate readings and identify patients who may require further cardiovascular evaluation.