Symptom Finder - Absent or Diminished Pulse
ABSENT OR DIMINISHED PULSE
Anatomy is once again the simplest way to recall the many causes of an absent or diminished pulse. By visualizing the arterial tree, we can recall the various causes. Beginning at the top of the tree, we have the heart, which should prompt the recall of shock and CHF. Proceeding down the tree to the aorta we have dissecting aneurysm, Takayasu disease, and coarctation of the aorta as prominent causes of absent or diminished pulses. A large saddle embolism at the terminal aorta may cause absent or diminished pulses in the lower extremities. Arteriosclerosis of the terminal aorta as seen in Leriche syndrome may produce a similar picture. Proceeding further down the tree to the larger arteries, we are reminded of the subclavian steal syndrome in the upper extremities and femoral artery thrombosis, embolism, or arteriosclerosis affecting the lower extremities.
Extrinsic pressure from a thoracic outlet syndrome may also affect the subclavian artery. Finally reaching the peripheral arteries, we encounter peripheral arteriosclerosis, embolism, and thrombosis. These arteries also may be affected by external compression in fractures, tumors, and other masses of the extremities. An arteriovenous fistula of the extremity arteries may produce an absent or diminished pulse also. Significant anemia or dehydration may produce a diminished pulse in all extremities, but of course, this is usually associated with shock.
Approach to the Diagnosis
Clinically it is useful to take the blood pressure on all four extremities and do a thorough examination of the optic fundus and heart. Ultrasonography of the vessels involved is an excellent non invasive technique for further evaluation. If a dissecting aneurysm is suspected, a CT scan of the chest or aortography and surgery must be planned immediately. Laboratory evaluation includes a CBC, blood cultures to rule out bacterial endocarditis, serial ECGs, and serial cardiac enzymes. Arteriography of the vessel or vessels involved will ultimately be necessary in most cases. Magnetic resonance angiography is an expensive but adequate alternative in some cases when contrast arteriography is considered hazardous.
Other Useful Tests
1. Chest x-ray (dissecting aneurysm)
2. Sedimentation rate (mediastinitis, collagen disease)
3. Urinalysis (dissecting aneurysm)
4. Chemistry panel (myocardial infarction with embolism)
5. Venereal disease research laboratory (VDRL) test (syphilitic
aneurysm)
6. Echocardiography (CHF)
7. 24-hour Holter monitor (cardiac arrhythmia)
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8. Cardiology consult
9. Four-vessel cerebral angiography (subclavian steal syndrome)
10. Plain films of the extremities (fracture, mass)
11. Protein electrophoresis (collagen disease, multiple myeloma)
Anatomy is once again the simplest way to recall the many causes of an absent or diminished pulse. By visualizing the arterial tree, we can recall the various causes. Beginning at the top of the tree, we have the heart, which should prompt the recall of shock and CHF. Proceeding down the tree to the aorta we have dissecting aneurysm, Takayasu disease, and coarctation of the aorta as prominent causes of absent or diminished pulses. A large saddle embolism at the terminal aorta may cause absent or diminished pulses in the lower extremities. Arteriosclerosis of the terminal aorta as seen in Leriche syndrome may produce a similar picture. Proceeding further down the tree to the larger arteries, we are reminded of the subclavian steal syndrome in the upper extremities and femoral artery thrombosis, embolism, or arteriosclerosis affecting the lower extremities.
Extrinsic pressure from a thoracic outlet syndrome may also affect the subclavian artery. Finally reaching the peripheral arteries, we encounter peripheral arteriosclerosis, embolism, and thrombosis. These arteries also may be affected by external compression in fractures, tumors, and other masses of the extremities. An arteriovenous fistula of the extremity arteries may produce an absent or diminished pulse also. Significant anemia or dehydration may produce a diminished pulse in all extremities, but of course, this is usually associated with shock.
Approach to the Diagnosis
Clinically it is useful to take the blood pressure on all four extremities and do a thorough examination of the optic fundus and heart. Ultrasonography of the vessels involved is an excellent non invasive technique for further evaluation. If a dissecting aneurysm is suspected, a CT scan of the chest or aortography and surgery must be planned immediately. Laboratory evaluation includes a CBC, blood cultures to rule out bacterial endocarditis, serial ECGs, and serial cardiac enzymes. Arteriography of the vessel or vessels involved will ultimately be necessary in most cases. Magnetic resonance angiography is an expensive but adequate alternative in some cases when contrast arteriography is considered hazardous.
Other Useful Tests
1. Chest x-ray (dissecting aneurysm)
2. Sedimentation rate (mediastinitis, collagen disease)
3. Urinalysis (dissecting aneurysm)
4. Chemistry panel (myocardial infarction with embolism)
5. Venereal disease research laboratory (VDRL) test (syphilitic
aneurysm)
6. Echocardiography (CHF)
7. 24-hour Holter monitor (cardiac arrhythmia)
118
8. Cardiology consult
9. Four-vessel cerebral angiography (subclavian steal syndrome)
10. Plain films of the extremities (fracture, mass)
11. Protein electrophoresis (collagen disease, multiple myeloma)
