When a blood pressure reading shows a high top number (systolic) and a low bottom number (diastolic), it signals an unusual pattern. Systolic pressure is the force exerted when the heart beats, pushing blood into the arteries. Diastolic pressure is the pressure remaining in the arteries when the heart rests between beats. This combination creates a significantly larger gap than is typical, suggesting a change in the condition of the body’s largest blood vessels.
Understanding Wide Pulse Pressure
The difference between the systolic and diastolic pressures is known as the Pulse Pressure. Calculating this value is a simple subtraction; for example, a reading of $120/80$ mmHg yields a pulse pressure of $40$ mmHg, which is considered normal for adults. The pattern of high systolic and low diastolic pressure results in an increased, or wide, pulse pressure.
A pulse pressure consistently measuring $50$ mmHg or more suggests an elevated risk for cardiovascular events. Experts generally consider $60$ mmHg or higher to be a clinically significant widened pulse pressure. This wide gap indicates that the arteries are experiencing greater mechanical stress with each heartbeat.
This measurement provides direct insight into the health and flexibility of the large arteries. It reflects the volume of blood the heart ejects and the ability of the arteries to expand (arterial compliance). A wider-than-normal pulse pressure means the cardiovascular system is operating under conditions of reduced arterial flexibility.
Primary Causes of Increased Pulse Pressure
The most frequent reason for a high systolic and low diastolic reading is the loss of elasticity in the major arteries, a process called arteriosclerosis. This stiffening typically occurs with advancing age as elastic fibers are replaced by stiffer tissue. When the heart contracts, rigid arteries cannot expand effectively to cushion the surge of blood, causing the systolic pressure to spike upward.
During the heart’s resting phase, stiff arteries cannot recoil to maintain pressure, causing the diastolic pressure to fall quickly. This mechanism creates the wide gap where the top number is pushed up and the bottom number is pulled down.
Other Contributing Factors
Other conditions affecting the heart’s output or the aortic valve can also cause a wide pulse pressure. Aortic regurgitation is a heart valve condition where the aortic valve does not close completely, allowing blood to leak backward. This backflow causes the diastolic pressure to drop lower than normal.
Hyperkinetic states, which cause unusually high cardiac output, can also widen the pulse pressure. Examples include severe iron deficiency anemia or hyperthyroidism (an overactive thyroid gland). These conditions increase the amount of blood pumped per minute, raising the systolic pressure.
Health Implications of This Reading Pattern
A wide pulse pressure is a significant, independent predictor of future cardiovascular issues, particularly in older adults. The increased pressure differential suggests that the heart and blood vessels are consistently enduring excessive mechanical strain. Every $10$ mmHg increase in pulse pressure has been associated with a rise in the risk of developing cardiovascular disease.
The high systolic pressure places a greater workload on the heart muscle, contributing to left ventricular hypertrophy (thickening of the heart’s main pumping chamber). Over time, this overworked muscle can become less efficient, potentially leading to heart failure.
The low diastolic pressure is also problematic because the heart muscle receives its main blood supply through the coronary arteries during diastole. A low diastolic reading can compromise blood flow to the heart, increasing the risk of ischemic events like heart attacks, especially if arteries are narrowed by plaque. Furthermore, a widened pulse pressure is linked to an increased risk of stroke and can accelerate the progression of chronic kidney disease.
Management and Treatment Options
Addressing a wide pulse pressure centers on managing the heightened systolic blood pressure and treating underlying conditions contributing to arterial stiffness. Lifestyle modifications are foundational for improving arterial health. These include adopting a diet low in sodium and saturated fats, such as the DASH eating plan, and engaging in regular aerobic physical activity to improve blood vessel elasticity.
Pharmacological treatment often targets the mechanisms involved in arterial stiffness. Certain antihypertensive medications, such as thiazide diuretics and long-acting calcium channel blockers, are effective at reducing pulse pressure. These medications work to lower the systolic pressure without excessively dropping the diastolic pressure.
It is important that treatment does not lower the diastolic pressure too much, often cautioned against falling below $60$ mmHg, especially in older individuals. An overly low diastolic pressure can reduce blood flow to the coronary arteries and cause harm. Managing conditions like hyperthyroidism or aortic regurgitation is also a necessary step to narrow the pressure gap and reduce cardiovascular risks.