Davis's Lab & Diagnostic Tests
Cardiac Catheterization
General
Synonym/Acronym:
Angiography of heart, angiocardiography, cardiac angiography, cardiac catheterization, cineangiocardiography, coronary angiography, coronary arteriography.
Rationale
To visualize and assess the heart and surrounding structure for abnormalities, defects, aneurysm, atherosclerosis, and tumors.
Patient Preparation
There are no activity restrictions unless by medical direction. Instruct the patient to fast and restrict fluids for 2 to 4 hr, or as ordered, prior to the procedure. Fasting may be ordered as a precaution against aspiration related to possible nausea and vomiting. The American Society of Anesthesiologists has fasting guidelines for risk levels according to patient status. More information can be located at www.asahq.org.
Note: Protocols regarding the use of iodinated contrast medium in patients with impaired kidney function and who are receiving metformin or drugs containing metformin for type 2 diabetes may vary by facility; the drug may be discontinued on the day of the test and continue to be withheld for 48 hr after the test. Kidney function should be assessed per facility protocol before use of metformin is resumed (e.g., Cr, eGFR, hydration or clinical assessment).
Regarding the patient’s risk for bleeding, the patient should be instructed to avoid taking natural products and medications with known anticoagulant, antiplatelet, or thrombolytic properties or to reduce dosage, as ordered, prior to the procedure. Number of days to withhold medication is dependent on the type of anticoagulant. Note the last time and dose of medication taken. Protocols may vary among facilities.
Normal Findings
- Normal great vessels and coronary arteries.
| Pressures | Description of What Measured Parameter Represents | Normal Value |
|---|---|---|
| Arterial blood pressure (also known as routine blood pressure) | The pressure in the brachial artery; one of the significant vital signs, it reflects the pressure the heart exerts to pump blood through the circulatory system | Systolic (90–120) mm Hg/diastolic (60–80) mm Hg |
| Mean arterial pressure (MAP) | The average arterial pressure of one cardiac cycle; considered a better indicator of perfusion than routine blood pressure but obtainable only by direct measurement during cardiac catheterization | 70–105 mm Hg |
| Left ventricular pressures | Peak pressure in the left ventricle during systole/peak pressure in the left ventricle at the end of diastole; indication of contractility of the heart muscle | Systolic (90–140) mm Hg/diastolic (4–12) mm Hg |
| Central venous pressure (CVP); also right atrial pressure (RAP) | The right-sided ventricular pressures exerted by the central veins closest to the heart (jugular, subclavian, or femoral); used to estimate blood volume and venous return | 2–6 mm Hg |
| Pulmonary artery pressure (PAP) | The pressures in the pulmonary artery | Systolic (15–30) mm Hg/diastolic (4–12) mm Hg |
| Pulmonary capillary wedge pressure (PCWP); also pulmonary artery occlusion pressure (PAOP) | The pressure in the pulmonary vessels; used to provide an estimate of left atrial filling pressure, to provide an estimate of left ventricle pressure during end diastole, and as a way to measure ventricular preload | 6–12 mm Hg |
| Volumes | Description of What Measured Parameter Represents | Normal Value |
| Cardiac output | The amount of blood pumped out by the ventricle of the heart in 1 min | 4–8 L/min |
| Cardiac index | The cardiac output adjusted for body surface to provide the index, which is a more precise measurement; used to assess the function of the ventricle | 2.8–4.2 L/min/m2 |
| Arterial oxygen saturation | The concentration of oxygen in the blood | 95%–100% |
| Stroke volume (SV) | The amount of blood pumped by each ventricle with each contraction in a heartbeat | 60–90 mL/beat |
| Stroke volume index (SVI) | The stroke volume adjusted for body surface to provide the index, which is a more precise measurement | 33–47 mL/m2 |
| Ejection fraction (EF) | Stroke volume expressed as a percentage of end diastolic volume | 55%–70% |
Critical Findings and Potential Interventions
- Aneurysm
- Aortic dissection
Timely notification to the requesting health-care provider (HCP) of any critical findings and related symptoms is a role expectation of the professional nurse. A listing of these findings varies among facilities.
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