Clots and blood travel

[terg888]

how long would it take a dislodged clot to reach the heart/lungs/brain to cause an MI, CVA, PE? Like someone who develops a DVT after a long flight, and then the clot breaks free in the bloodstream?

[classicdame, MSN, EdD]

minutes to days, depending on viscosity of blood, blood pressure, anatomy (twists and turns in the vessels), how much exercise the person is getting, any meds they are on (like blood thinners)---no such thing as one answer, as every patient is different.

[Esme12, ASN, BSN, RN]

What makes you ask? what semester are you?

[nurseprnRN, BSN, RN]

As a refresher, please take a look at normal vascular anatomy.

Body > Veins > Vena Cava > Right Atrium > tricuspid valve > Right Ventricle > pulmonic valve > Pulmonary Artery

> LUNGS

>Pulmonary Vein > Left Atrium > mitral valve > Left ventricle > aortic valve > Arteries > Body

Given normal anatomy, i.e., no intracardiac malformations, there is simply no way for a floating object to get to the left heart at all; it gets strained out in the pulmonary capillary bed. As a matter of fact, that's why you have a pulmonary capillary bed, to act as a strainer for all the microemboli you have in the course of an active life.

The only way a deep VEIN thrombosis can get to the cerebral arterial circulation is if there is a direct connection between the venous side and the arterial side in the heart AND the venous pressure is HIGHER than the arterial pressure.

Anyone with an atrial or ventricular septal defect AND a right-to-left shunt, who would be at risk for arterial embolus of venous origin, and this would be bad. However, since in most people, the left heart pressures are significantly higher than right heart pressures (by a factor of five to ten, more or less), any air or clot in the right heart keeps going right on out the pulmonary artery to the capillary bed. Unsuspected ASDs are a known cause of stroke in younger people who lack other risk factors-- think of the much-beloved erstwhile heart and soul of the Patriots' line, Tedy Bruschi, whose stroke fortunately resolved and whose ASD was repaired endoscopically; he went back to football for the rest of that season and the next one (although he has since retired). As a matter of fact, most ASDs are found by accident or on post for unrelated issues, since the left-to-right shunt doesn't do much harm unless it's so huge that you get bad pulmonary hypertension and capillary bed damage (seen in single ventricle, for example).

I hope this helps. It doesn't answer your question, but it should clear up your misconception. It's a common misconception even among nurses, who should know better-- so many people think they can't irrigate a little clot out of an IV because they'll cause a stroke, or that air bubbles in the IV tubing will be lethal. No intracardiac abnormality, not gonna happen.