ARRT Patient Care Practice Exam

In the blood pressure reading 145/75 mmHg, what does 145 represent?

1. Phase of relaxation of the cardiac muscle tissue

2. Phase of contraction of the cardiac muscle tissue

3. A higher than average diastolic pressure

4. None of the above

The correct answer is: A higher than average diastolic pressure

In the blood pressure reading of 145/75 mmHg, the first number, which is 145, represents the systolic pressure. This is the pressure within the arteries when the heart muscle contracts and pumps blood into the circulation. During this phase, the heart is actively working to push blood through the arteries, leading to an increase in pressure. Understanding the distinctions between systolic and diastolic pressures is crucial. The second number, 75 in this case, represents the diastolic pressure, which is measured when the heart is at rest between beats. Thus, the systolic reading of 145 indicates a higher-than-normal level of pressure during contraction, reflecting a potential concern such as hypertension. The choices related to the phases of the cardiac cycle are significant. The options regarding the diastolic pressure do not address the summation of the readings correctly since they imply that the 145 measurement relates to a phase of relaxation or contraction but specifically around the context of diastolic pressure, which it does not. Overall, recognizing the role of systolic pressure in the reading is essential in understanding cardiovascular health.