Irregular heartbeat- curiosity

Do you mean sinus arrhythmia? It has something to do with parasympathetic stimulation and inhibition in relation to respiration....inhaling decreases vagal tone (lets off the brakes) and exhaling increases it (puts the brakes on).

Maybe- does sinus arrhythmia occur only during deep respiration? If normal respiration doesn't change a rhythm, but deep respiration regulates it- is that within the definition of a sinus arrhythmia? I thought that sinus arrhythmia was an irregularity that occured during normal respiration...? *curious* Also- does the irregularity of a sinus arrhythmia include more than just accelerations/decelerations? Does it also include inconsistant beats that regulate with deep breathing? I guess I'm just weird- all these little nuances fascinate me. LOL

Thanks for the "why" :)

hmm not sure... i did learn today that with cardiac tamponade (fluid filling in pericardial sac) that a s/s is pulsus paradoxus. This means that when the pt breathes in there is a drop in systemic BP >10mm Hg). I would assume the deeper they breath in the greater the drop in BP b/c the air fills the lungs, which push on the heart, surrounded w/ fluid, & squeezing it & slowing down CO, HR......pretty cool stuff, to learn, not to have!

hmm not sure... i did learn today that with cardiac tamponade (fluid filling in pericardial sac) that a s/s is pulsus paradoxus. This means that when the pt breathes in there is a drop in systemic BP >10mm Hg). I would assume the deeper they breath in the greater the drop in BP b/c the air fills the lungs, which push on the heart, surrounded w/ fluid, & squeezing it & slowing down CO, HR......pretty cool stuff, to learn, not to have!

Actually it's the decreased intrathoracic pressure that causes increased venous return to the right side of the heart, leading to increased RV filling pressures, which further pushes the septum into the left ventricle (septum is already pushed into LV by the pressure from the pericardial effusion/tamponade), decreasing LV stroke volume.