Stylized blood pressure gauge highlighting diastolic reading, with heart and micro-vessels in background.

Decoding Blood Pressure: Why Diastolic Matters in Septic Shock

Lena Voss in Health & Wellness December 2025 • 4 min read.

"Beyond the Numbers: Understanding DAP's Critical Role in Cardiovascular Health During Sepsis"

In the world of medicine, arterial blood pressure is a crucial indicator of cardiovascular status. While doctors diligently manage diastolic arterial pressure (DAP) when treating chronic hypertension, it's often overlooked in the fast-paced environment of intensive care. Is this neglect a missed opportunity to improve patient outcomes?

The current debate among intensivists highlights a critical question: Are we underestimating the importance of DAP in managing critically ill patients? This oversight may stem from the traditional focus on systolic arterial pressure and mean arterial pressure (MAP) in defining shock states. However, there are compelling reasons to consider DAP as a vital factor in patient care.

This article will show how the diastolic arterial pressure crucial factor of arterial tone and the upstream pressure influencing the perfusion of the left ventricle, ultimately impacting cardiovascular outcomes in septic shock.

Why Diastolic Pressure Matters: Arterial Tone and Left Ventricular Perfusion

Stylized blood pressure gauge highlighting diastolic reading, with heart and micro-vessels in background.

A low DAP is primarily an indicator of depressed arterial tone. While bradycardia (slow heart rate) or arterial stiffness can play a role, a low DAP is a strong sign of reduced arterial tone in critically ill patients. Although tachycardia could theoretically lead to higher DAP, in vasodilatory shock, decreased arterial tone often counteracts this effect.

When DAP falls below 40 mmHg, particularly in the presence of tachycardia, it strongly suggests significantly depressed arterial tone, potentially warranting the initiation of vasopressors. Surprisingly, recent Surviving Sepsis Campaign (SSC) guidelines omit the mention of DAP as a trigger for vasopressor use. Considering that fundamental physiology hasn't changed, this omission seems to be an oversight.

DAP as a Perfusion Indicator: DAP acts as the upstream pressure for the left ventricle's perfusion, which occurs only during diastole.
Myocardial Ischemia Risk: Low DAP, common in early septic shock, elevates the risk of myocardial ischemia, especially in individuals with pre-existing coronary artery disease (CAD).
Coronary Artery Disease Impact: In CAD patients, lower downstream pressure increases ischemia risk due to existing coronary artery stenosis.
Underestimated Risk: The risk of myocardial ischemia in septic shock is often underestimated because it is often thought to be associated with normal or high coronary blood flow.

Research indicates that even when coronary blood flow appears normal in septic shock patients without prior CAD, low DAP can compromise myocardial function. In fact, studies show myocardial hypoxia (reduced lactate uptake) in patients with low coronary blood flow values, and thus low DAP values [4]. Sepsis-related endothelial dysfunction and microcirculatory alterations can also affect the myocardium.

The Urgency of Considering Diastolic Pressure

In conclusion, diastolic arterial pressure is a vital variable to consider in septic shock, serving as a marker of arterial tone and upstream pressure for left ventricular perfusion. Given the ease of obtaining DAP measurements via arterial catheters, neglecting it is a disservice to patients. Prioritizing DAP assessment can lead to earlier recognition of compromised arterial tone, enabling timely initiation of vasopressor therapy and potentially improving outcomes in this critical condition.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1016/j.jcrc.2018.10.032, Alternate LINK

Title: Importance Of Diastolic Arterial Pressure In Septic Shock: Pro

Subject: Critical Care and Intensive Care Medicine

Journal: Journal of Critical Care

Publisher: Elsevier BV

Authors: Olfa Hamzaoui, Jean-Louis Teboul

Published: 2019-06-01

Everything You Need To Know

What is diastolic arterial pressure (DAP), and what does it measure?

Diastolic arterial pressure (DAP) is a crucial measurement of arterial blood pressure. It reflects the pressure in the arteries when the heart is at rest, between beats. Unlike systolic pressure, which measures pressure during heart contraction, DAP provides insights into arterial tone and the efficiency of blood flow during the critical diastolic phase. A low DAP, especially in critical conditions like septic shock, indicates depressed arterial tone and can have serious implications for patient outcomes.

Why is diastolic arterial pressure (DAP) so important in the context of septic shock?

Diastolic arterial pressure (DAP) is significant in septic shock because it serves as a key indicator of arterial tone, which directly influences how well blood flows throughout the body. Low DAP often signifies reduced arterial tone, potentially leading to inadequate perfusion of vital organs, including the heart. Furthermore, DAP acts as the upstream pressure for the left ventricle's perfusion. In septic shock, understanding and managing DAP is vital for ensuring sufficient blood supply to the heart and other organs, ultimately impacting patient outcomes.

What are the potential implications of low diastolic arterial pressure (DAP) in patients with septic shock?

A low diastolic arterial pressure (DAP) can lead to myocardial ischemia, which is a condition where the heart muscle doesn't receive enough oxygen. This risk is particularly elevated in septic shock, especially for individuals with pre-existing coronary artery disease (CAD). In patients with CAD, a lower DAP can exacerbate the risk of ischemia due to the existing narrowing of coronary arteries. Even without prior CAD, low DAP can compromise myocardial function because it influences perfusion of the left ventricle. Therefore, monitoring and addressing low DAP is crucial to prevent or minimize heart damage.

What are the implications of neglecting diastolic arterial pressure (DAP) in the management of septic shock?

In the context of septic shock, the implications of neglecting diastolic arterial pressure (DAP) are significant. Failing to consider DAP can lead to delayed recognition of compromised arterial tone. This delay might mean that the timely initiation of vasopressor therapy is missed, potentially worsening patient outcomes. The omission of DAP in clinical guidelines raises concern because DAP is easily measured using arterial catheters, and it provides crucial information about arterial health, that can help improve outcomes in this critical condition.

How does diastolic arterial pressure (DAP) relate to arterial tone, and why does this matter?

The relationship between diastolic arterial pressure (DAP) and arterial tone is direct: Low DAP is a strong indication of depressed arterial tone. Arterial tone refers to the degree of constriction or dilation in the arteries, affecting blood flow and pressure. In septic shock, reduced arterial tone can result in insufficient blood flow, leading to organ dysfunction. Understanding this relationship is crucial for clinicians because it highlights the importance of monitoring DAP as a key parameter for assessing arterial health and guiding treatment strategies, such as using vasopressors when needed.