A site for medical students - Practical,Theory,Osce Notes

Showing posts with label vitals monitoring.. Show all posts
Showing posts with label vitals monitoring.. Show all posts

What are the causes of radiofemoral delay

Normally the radial and femoral pulses are palpated simultaneously.If there an appreciable delay in the femoral pulse compared to radial pulse it is called as radiofemoral delay.
Radiofemoral delay is seen in following conditions
1. Coarctation of aorta
2. Aortoarteritis
3. Atheroslerosis of aorta
4. Thrombosis or embolism of aorta.    
1. Coarctation of aorta
Coarctation of the aorta may lead to hypertension in the circulatory system serving the head and upper limbs.It is an important bedside diagnostic clue in a young hypertensive patients
Narrowing or constriction of the aortic lumen may occur anywhere along its length but it is most common distal to the origin of the left subclavian artery near the insertion of the ligamentum arteriosum. Coarctation is seen in approximately 7% of patients with congenital heart disease,this  is more common in males than females, and is particularly frequent in patients with gonadal dysgenesis for example Turner syndrome. 
Clinical manifestations of coarctaion of aorta is dependent on the following factors
  • The site and extent of obstruction 
  • Presence of associated cardiac anomalies
The most common congenital heart disease associated with coarctation is a bicuspid aortic valve. Circle of Willis aneurysms is seen in up to 10%, and pose a high risk of sudden rupture and death.
2. Aortoarteritis.
Aortitis, a term referring to inflammatory disease of the aorta, it may be caused by
  • Large vessel vasculitides such as Takayasu’s arteritis and giant cell arteritis,
  • Rheumatic and HLA-B27–associated spondyloarthropathies
  • Beh├žet’s syndrome
  • Antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitides
  • Cogan’s syndrome
  • Infections such as syphilis, tuberculosis, and Salmonella
Clinical presentation of aortitis
Aortitis may result in th following features
  • Aneurysmal dilation and aortic regurgitation
  • Occlusion of the aorta and its branch vessels
  • Acute aortic syndromes.
Prototype of aortoarteritis is takayasu arteritis its signs and symptoms are given below
There are two phases for this disease.Initial inflammatory phase followed by secondary pulseless phase.
Initial "inflammatory phase"
Initial "inflammatory phase" characterized by systemic illness with signs and symptoms of malaise, fever, night sweats, weight loss, joint pain, fatigue, and fainting is seen in some patients. 
Fainting episodes are due to subclavian steal syndrome or carotid sinus hypersensitivity. Nonspecific markers of inflammation such as anemia and marked elevation of the ESR or C-reactive protein is seen. 
Secondary pulseless phase
The "pulseless phase" is characterized by vascular insufficiency due to intimal narrowing of the vessels presenting as
  • Arm or leg claudication
  • Renal artery stenosis causing hypertension, 
  • Neurological features due to decreased blood flow to the brain.These symptoms vary depending on the degree and  the nature of the blood vessel obstruction; it can range from lightheadedness to seizures in severe cases
  • One rare,but important feature of the Takayasu's arteritis is eye involvement in form of visual field defects, vision loss, or retinal haemorrhage
Some individuals with Takayasu's arteritis may present with only late vascular changes, without a preceding inflammatory phase
In the advanced stage, weakness of the arterial walls may give rise to localized aneurysms. And there is risk of rupture and vascular bleeding so requires frequent monitoring. 
3. Atherosclerosis of aorta.
Atherosclerosis may affect the either the thoracic and abdominal aorta. 
Occlusive aortic disease caused by atherosclerosis usually it is a confined to the distal part of abdominal aorta below the origin of renal arteries.Frequently the disease extends to the iliac arteries Claudication pain involves the buttocks, thighs, and calves muscle and may be associated with impotence in males (Leriche syndrome)
The severity of the clinical presentation  depends on the adequacy of collaterals.If there is sufficient collateral blood flow, even a complete occlusion of the abdominal aorta can occur without the development of ischemic symptoms.
The physical findings include the following
  • Absence of femoral and other distal pulses bilaterally 
  • An audible bruit over the abdomen (usually at or below the umbilicus) and the common femoral arteries. 
  • Atrophic skin, loss of hair, and coolness of the lower extremities 
  • In advanced cases of ischemia, rubor on dependency and pallor on elevation may be observed.
The diagnosis of atherosclerosis of aorta is usually established by physical examination and noninvasive testing which include
  • Leg pressure measurements,
  • Doppler velocity analysis
  • Pulse volume recordings
  • Duplex ultrasonography. 
  • The extend of lesion may be defined by MRI, CT, or conventional aortography, specifically performed for the purpose of  revascularization. 
Catheter-based endovascular or operative treatment is indicated in patients with lifestyle-limiting or debilitating symptoms of claudication and in patients with critical limb ischemia.
4. Thrombosis or embolism of aorta.
Acute occlusion in the distal abdominal aorta is a medical emergency as it threatens the viability of the lower extremities; This is usually from an occlusive or saddle embolus that almost always originates from the heart. Rarely, acute occlusion of aorta may be seen as a  result of in situ thrombosis in a preexisting severely narrowed segment of the aorta.
The clinical picture is one of acute ischemia of the lower extremities. 
  • Severe rest pain
  • Coolness, and pallor of the lower extremities and the absence of distal pulses bilaterally are the usual manifestations.
Diagnosis is by MRI, CT, or aortography.
Emergency thrombectomy or revascularization is the treatment.

What is the mechanism of radiofemoral delay?

What is radiofemoral delay?
Simultaneous palpation of two pulses can be diagnostic in radiofemoral delay. Normally the femoral and the radial pulses occur simultaneously.When the femoral pulse lags behind the radial (radio-femoral delay), occlusion of the aorta either due to coarctation or atherosclerosis is diagnosed. Reduced amplitude and delayed timing of the pulses in the lower body compared to the pulses in the upper body are classic features of aortic coarctation. All hypertensive patients should be examined for radiofemoral delay. Unilateral absence of a pulse can aid in the diagnosis of a dissected aortic aneurysm.
Where to palpate for femoral and radial pulse ?
Radial pulse is located on the lateral of the wrist (radial artery). This  can also be found in the anatomical snuff box.
Femoral pulse is located in the inner thigh, at the mid-inguinal point, halfway between the pubic symphysis and anterior superior iliac spine (femoral artery).
Diminished or absent femoral pulses indicating proximal occlusion is often seen in peripheral vascular disease.
What is the mechanism of radiofemoral delay?
Similar to aortic stenosis, coarctation of aorta cause a decrease in the rate of ejection of blood because of narrowing of vessel  and the Venturi effect sucking the vessel  walls inwards, it will create a reduction in the flow and amplitude of the pulse distal to the occlusion.
In addition, the following factors are essential in the mechanism of a pulse that is seen in any type of coarctation
The coarctation creates a pulse wave reflection sitewhich is much closer to the heart. This means the pulse wave is reflected earlier and faster, resulting in a higher blood pressure proximal to the stricture.
There are fewer cushioning properties (i.e. less compliance of the arterial segment involved
proximal to the coarctation), this will further increase blood pressure at or just prior to the stricture.
The flow and pressure pulsations are damped in the long and dilated collateral vessels that form to
provide flow distal to the coarctation.
The differential effects of the anatomical variations in coarctation of aorta 
  • The differential effects of the anatomical variations in coarctation of aorta may be diagnosable at the bedside if you carefully compare the brachial pulses between the two arms.
  • If both the brachial pulses and the carotids are strong with delayed or diminished femoral pulses, it indicate that the coarctation is distal to the left subclavian artery
  • When the left brachial arterial pulse is weak or diminished compared to the right, it indicate that the coarctation is proximal to the left subclavian artery.
  • If the right subclavian has an anomalous origin from the aorta distal to the coarctation, then the right brachial pulse will be diminished or poor.
What is Sign value
There is limited evidence as to the value of the sign and this can be difficult to elicit. The presence of the systolic murmur that is heard under the left clavicle or under the left scapula caused by turbulent blood flow across the coarctation is said to be more common.

Examination of pulse

How to examine the Pulse ?

What are the variations in pulse rate?

Bradycardia and its causes

Relative bradycardia and relative tachycardia

What is pulse deficit?

What is pulse volume and what are its alterations?

High volume pulse and its causes

What are the causes of low volume pulse?

What is water-hammer pulse ?

What is Hyperkinetic Pulse?

High volume jerky pulse (Spike and Dome Pulse)

What is anacrotic pulse?

What is Dicrotic pulse

What is catacrotic pulse?

What is pulsus alternans ?

Pulses bigeminus

Pulses paradoxus or Kussmaul's pulse

What is pulsus bisferiens ?

Describe the pulse in complete heart block (CHB)

How to assess the condition of the arterial wall?

What is the cause of radioradial and radiofemoral delay?

What are the basic bedside features of coarctation of aorta ?

Different cardiac rhythms

Temperature recording and fever

Describe the pulse in complete heart block (CHB)

In complete heartblock the following chanes are observed
  1. Pulse rate— 36 to 40 per minute and is called as bradycardia
  2. Rhythm—Regular.
  3. Volume—High.
  4. Condition of the arterial wall-may be thickened (in  patients with advanced age),
  5. No radio-radial nor any radio-femoral delay.
  6. Character of the pulse may be water-hammer character.
  7. All the peripheral pulses are palpable.
  8. Fixed pulse is seen that is unaltered after exercise ,pyrexia or injection of atropine
  9. In CHB carotid artery may show carotid dance at the rate of 36-40 per minute, and internal jugular vein showing atrial pulsation at a rate of 72 per minute with cannon waves appearing from time to time.