Location of pacemaker cells in the heart
Common Questions and Answers about Location of pacemaker cells in the heart
pacemaker
Usually, the heart muscle cells keep time more slowly than normal pacemaker cells. This allows the pacemaker cells within the SA node to be in control of generating and pacing the heartbeat. But, if a particular group of cells in areas remote from the SA node become extra- or hyper-excitable they can take over as the pacemaker for one or several beats, or for a longer term.
You might think of the heart's cells as a schoolyard full of young boys playing soccer.
hypokinesis can also be the result of stunned cells. Stunned heart cells affected by a heart attack can be revitalized if blood/oxygen is quickly provided within a few hours to the area affected by an acute heart attack.
Akinesis is different from hypokinesis in that the heart cells affected are necrotic (dead). Stem cell therapy may be helpful for that condition.
Five years ago I had hypokinesis of the left ventricle wall and a low EF.
Alcohol may trigger an irregular beat by changing the chemical structure of the cells in the heart. Thus it is the chemicals that really cause the extra beats. All these drugs change the way cells emit and take in chemicals (potassium, etc). In this way it is intented that all the cells become synchronized--thus no irregular beats.
Thus the real cause is that cells develop the propensity for irregularity, and no one knows why this happens.
If symptoms not controlled with meds, then a stent implant would be the best option. Sometimes the location of the lesion, and size my preclude the stent option and a bypass would be the remaining option.
There is about 26% of the heart population that don't know they have a heart problem and continue with their daily activities without symptoms. The 24% is in the heart failure range (<30%), but with proper medication the the heart's EF can be increased.
When the electrical system in your heart goes a bit haywire (like a blown fuse or a power surge) then the cells in the heart can react by causing a premature heart beat.
Premature beats of the ventricles or atria are not (in themselves) dangerous and rarely cause any further complications. However, since your heart has been given an artificial pacemaker for whatever reason, it stands that your electrical system is likely not functioning properly.
Mine was AVRT, and was located in the left side of the heart well away from the AV node, the sensitive area. Others with right sided AVNRT may have a location close to or perhaps actually part of the AV Node. In this case care must be taken. Some docs will use cryogenic catheters to first chill the area to turn it off. If they decide that's the location, they'll continue to freeze the spot and sever the pathway. If it's not the spot, the location warms and returns to normal.
It's interesting that everyone has irregular beats--but most people simply don't feel them. We sensitive types do.
Perhaps you've read what actually happens during an ectopic beat? If not, here's a simplified rundown:
The 'Pacemaker' in the upper right atrium normally sets the heart rate, but it's important to know that every cardiac cell in the heart is naturally rhythmic and contractile.
The sinus atrial node is a clump of cells in your heart that put out an electrical current that causes the rest of your cells in the atrial center of your heart to contract. The electrical current continues into the ventricular node and causes the bottom of the heart to contract immediately after that.
This goes all the way down to the bottom of the heart. The front of the left ventricle has a small part that is also receiving less oxygen. Diminished means less or smaller, so unless they've used the wrong terminology, I would suspect the heart muscle is alive but not receiving enough oxygen for exertion. If that amount was scar tissue, I would suspect you would be experiencing all kinds of serious health issues.
s nearly 30 years ago and I think heart failure would have begun years ago from that. What you need to establish is the cause of the heart failure. Have there been more blockages in the arteries that haven't been treated? was there as infection involved? I get the impression that artery blockages have been the cause, hence the pacemaker requirement because the normal cells transmitting the signal have been killed. The question would be, why didn't they treat those blockages?
And two, in the setting of this A fib and a slow heart rhythm, putting in a pacemaker may reduce the amount of atrial fibrillation you're having. But more importantly, the presence of a pacemaker will allow your doctor to put you on anti-arrhythmic medications safely.
If you have a tendency for a very slow heart rhythm, if you were placed on and anti-arrhythmic medication, your heart rate may get so slow you could get dizzy or pass out.
Thank you for the response.
Do you know if the test come back abnormal because the Pacemaker takes over? I don't know if this is normal or if I should be concerned. The 1st abnormal ECG was the afternoon after the surgery. The 2nd abnormal ECG was the following day.
Strictly speaking, palpitations are a particular awareness of your heartbeat, be it regular or irregular, regardless of the anatomical origin of the beat. It's interesting that everyone has irregular beats--but most people simply don't feel them. We sensitive types do.
You mention an uneven pulse. The very nature of PVCs is unevenness: The letters stand for 'premature ventricular contraction.
Usually, hypokinesis is caused by coronary artery blockage and an insufficient supply of oxygenated blood to the location of the heart cells. Several years ago I had hypokinesis and an EF below 29% (heart failure range), a stent and mediction revitalized the hibernating heart cells, and currently my heart is prumping normally.
Your hypokinesis may be in a location where there is insignificant heart wall movement normally so there is very little effect on the heart's contractility.
Yes, the condition can infect the heart's natural pacemaker. The heart's "natural" pacemaker is called the sinoatrial (SA) node or sinus node. It's a small mass of specialized cells in the top of the heart's right atrium (upper chamber). It makes the electrical impulses that cause your heart to beat.
The stress test involves imaging perfusion of the injection under different circumstances. The objective of the test is to determine heart muscle viability at the heart cell level.
Myocardial viability is based elementry cell function that includes cell membrane integrity (fibers, etc.) and/or preserved intermediary metabolism. Lack of both or one is considered a marker of cell necrosis. Mild to moderate irreversible defects represents viable myocardium.
d suppose that they hope/expect some cells stick there in the heart and then do their magic. The cells can be gotten from such places as the marrow (naturally, because of the hematopoeitic stem cells used in blood cancer therapy), but also from fat or muscle areas.
There is a presentation that was given at Hypertension2008 in Berlin this past summer, on the same topic, which stated that this approach is used more post-MI than in HF. They had some dramatic results in that setting, too.
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