*** Definition: Peripheral vascular disease is a narrowing of blood vessels that restricts blood flow. It mostly occurs in the legs, but is sometimes seen in the arms.
- PVD includes a group of diseases in which blood vessels become restricted or blocked -> atherosclerosis, blood clots -> that can lead to gangrene of the affected area.
- Both veins and arteries may be affected, but the disease is usually arterial.

*** Risk factors:
* High blood levels of the bad LDL cholesterol and triglycerides
* Low blood levels of the good HDL cholesterol
* Cigarette smoking
* Diabetes mellitus (both Type I and Type II diabetes)
* High blood pressure (hypertension) or a family history of hypertension
* A family history of atherosclerotic disease
* Chronic renal failure
* Overweight or obesity
* Physical inactivity.

*** Symptoms:
- Claudication - pain, weakness, numbness, or cramping in muscles due to decreased blood flow.
- Sores, wounds, or ulcers that heal slowly or not at all.
- Noticeable change in color (blueness or paleness) or temperature (coolness) when compared to the other limb.
- Diminished hair and nail growth on affected limb and digits .

*** Diagnosis:
+ A medical history.

+ Physical exams and tests:
Rose criteria:A test used by many medical professionals to screen for peripheral vascular disease is a series of 9 questions called the Rose criteria. The answers to these questions indicate whether you have peripheral vascular disease and how severe it is.

Ankle/brachial index (ABI): compares the blood pressure in the arm (brachial) with the blood pressure in the legs, an ABI above 0.90 is normal; 0.70-0.90 indicates mild peripheral vascular disease; 0.50-0.70 indicates moderate disease; and less than 0.50 indicates severe PDV.

Treadmill exercise test:walking on a treadmill, usually until you have symptoms (Alternative tests are available if you are unable to walk on a treadmill). A significant drop in leg blood pressures and ABIs after exercise suggests PVD. If the leg pulses are not palpable, the use of a portable Doppler flow probe will quickly reveal the absence or presence of an arterial flow.

+ Ultrasound, X-ray angiography and MRA (magnetic resonance imaging angiography) : To help locate blockages in your blood vessels.

*** Treatment:
* Change lifestyle: quit smoking, exercises, eat nutritious/ low-fat foods and avoid foods high in cholesterol, lose weight, control B.P/cholesterol/ blood sugar...

* Medications: -> treatment the intermittent claudication : Pentoxifylline (Trental), Cilostazol (Pletal) ; Antiplatelet agents, Anticoagulant agents, Thrombolytics.

* Interventional procedures: Percutaneous (through the skin) balloon angioplasty, or just "angioplasty," ( without surgery). When the obstructive lesions are long and involve most of the vessel -> bypass.

Pulsus paradoxus

- Pulsus paradoxus: an exaggeration of the normal variation in the pulse during the inspiratory phase of respiration, in which the pulse becomes weaker as one inhales and stronger as one exhales.
- On clinical examination, one can detect beats on cardiac auscultation during inspiration that cannot be palpated at the radial pulse.
- Normally during inspiration, systolic blood pressure decreases ≤10 mmHg, and pulse rate goes up slightly. This is because the intrathoracic pressure becomes more negative relative to atmospheric pressure. This increases systemic venous return, so more blood flows into the right side of the heart.
- PP is quantified using a blood pressure cuff and stethoscope (Korotkoff sounds), by measuring the variation of the systolic pressure during expiration and inspiration.
1. Inflate cuff until no sounds (like you normally do when taking a BP)
2. Slowly decrease cuff pressure until systolic sounds are first heard during expiration but not during inspiration, (note this reading) (1)
3. Slowly continue decreasing the cuff pressure until sounds are heard throughout the respiratory cycle, (inspiration and expiration)(note this second reading) (2)
4. If the pressure difference between the two readings (1) and (2) is >10mmHg, it can be classified as pulsus paradoxus.
- Causes
Cardiac:
* cardiac tamponade
* pericardial effusion
* pulmonary embolism
* cardiogenic shock
Pulmonary:
* tension pneumothorax
* asthma
* chronic obstructive pulmonary disease
Non-pulmonary and non-cardiac:
* anaphylactic shock
* superior vena cava obstruction