Pulse Arrival Time and Pulse Interval as Accurate Markers to Detect Mechanical Alternans

Area of Science:

• Cardiology
• Biomedical Engineering
• Physiology

Background:

• Mechanical alternans (MA) is a significant predictor of poor prognosis in heart failure and cardiomyopathy.
• Current MA detection requires invasive arterial pressure monitoring, limiting its clinical application.
• Understanding MA pathophysiology and developing non-invasive detection methods are crucial.

Purpose of the Study:

• To identify novel, non-invasive cardiovascular correlates of mechanical alternans (MA).
• To facilitate affordable and accessible MA detection for improved patient risk stratification.
• To advance the understanding of MA's underlying pathophysiology in the human heart.

Main Methods:

• Mechanical alternans (MA) was induced by ventricular pacing in 12 healthy subjects.
• Simultaneous recordings of arterial pressure, ECG, and respiration were analyzed.
• Cardiovascular correlates including dPdtmax, pulse arrival time (PAT), and pulse wave interval (PI) were assessed before and after beta-blockade.

Main Results:

• MA was detected in 30% of recordings, with prevalence reduced by beta-blockade (50% to 11%).
• Alternans in dPdtmax, PAT, and PI demonstrated high sensitivity and specificity for MA detection.
• PAT and PI alternans showed strong temporal synchronization with MA, suggesting their utility as non-invasive markers.

Conclusions:

• Cardiac contractility appears to be a key factor in the development of MA.
• Non-invasive markers such as PAT and PI are highly correlated with invasive MA measurements.
• These findings support the potential for affordable, non-invasive MA detection using PAT and PI for risk prediction in cardiovascular diseases.