The study of the physiology and pathology of the heart and the cardiovascular system.

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How to Study PR intervals as HRV Metrics? [on hold]

I am trying G. Clifford book about ECG Data Analysis 2006. RR intervals are mostly used as HRV metrics. PR intervals not because of low magnitude of detection. I would like to get some samples of such ...
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38 views

Can defibrillation (cardiac arrest treatment) be done with a vehicle spark plug? [on hold]

Can successful defibrillation (restarting the heart after cardiac arrest) be done with a spark plug from a vehicle (possibly offroad vehicle)? Is it POSSIBLE for this to work? Let's say you are stuck ...
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1answer
30 views

What is the relationship between stroke volume of blood and ventricular end-diastolic volume? [closed]

I do know what each term means. That is, i know that stroke volume is: the volume of blood pumped by each contraction of a ventricle, while ventricular end-diastolic volume is: the volume of blood in ...
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10 views

Is there any range for Aortic Valve Gradient?

I understand aortic valve gradient is pressure on the value (measured in mmHg). What I would like to know is if there has been any research that identified a minimum and maximum pressure value as the ...
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1answer
17k views

What is the effect of extra-cellular potassium concentration on heart rate and conduction velocity?

If the extracellular potassium concentration surrounding a myocyte increases, then the potassium gradient accross the cell membrane decreases, and therefore the resting membrane potential will become ...
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1answer
37 views

What is a lethal dose of THC?

With the oil form of THC being stronger then ever. What would happen if one was to take a stomach full of THC oil?
4
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1answer
143 views

Why do changes in preload not cause changes in end systolic pressure?

I am trying to understand why changes in preload do not cause concomitant changes in end systolic pressure. If you have preload enhancement than this should lead to an increase in cardiac output.....
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13 views

reduced rate of blood flow and thrombus

How does reduced rate of blood flow cause thrombus formation? Although thrombus is usually caused due to hematoma (clotted blood mass). So, in this regard, we can say that due to thrombus formation ...
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10 views

ECG Atlases of Many Years?

I am looking for ECG data/atlases of Many years in healthy individuals of age from 6 to 40 years old. I would like to study several processes/effects occurring in years. Note the long-term ECG data ...
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1answer
88 views

How are isovolumetric contraction and afterload related in the cardiac cycle?

In the cardiac cycle isovolumetric contraction occurs and causes a pressure gradient. The "afterload" is the pressure exerted on the ventricle from the artery. Is the afterload the cause of ...
3
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1answer
30 views

Why are vegetations in Infective endocarditis common on the atrial side?

Robbin's Pathology says that vegetations of IE are more common on the atrial side in AV valves. In Liebmann Sack's Endocarditis, which is a sterile (non bacterial) type of endocarditis, the underside ...
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5 views

How does the Sensitivity of Sokolev-Lyon indicators change by age?

I am studying the indicator and how diseases/age affect its sensitivity. However, no publication about it in PubMed and no luck in Escardio. How does the sensitivity of Sokolev-Lyon indicator and/...
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10 views

Pathogenesis of Cardiac Atypia?

I am studying the pathogenesis of atypia in cardiac cells where the etiology is most commonly irritation or infection and where the precancerous risk depends on the context of diagnosis. This fact ...
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1answer
25 views

Electrocardiogram: Missed beats in presence of Ectopic beats or Premature Atrial/Ventricular Contraction beats

I have been working on analyzing Electrocardiogram data. So far, i have identified Ectopic beats and Premature Atrial/Ventricular Contraction beats. I am working on identifying Missed Beat in the ...
2
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1answer
57 views

To determine no beating cardiomyocytes from ECG or video recording

I am trying to find data and some method by which I can see and say that there are some cardiomyocytes not working. I have reviewed many arrythmia data where I think I can see much cardiomyocetes ...
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16 views

Electrocardiogram: Difference between Atrial Fibrillation and Atrial Flutter

I have been working on analyzing Electrocardiogram data. I have read several documents related to conditions of the Atria during fibrillation and flutter, the most lucid being that atria quiver with ...
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51 views

Average Beginning of Action Potential in ECG by t-f HRV

I have some ECG data where I am estimating the average beginning of the action potential. I am interested in the discrete Fourier analysis of joint t-f HRV when input data is ECG. Frequency domain ...
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28 views

Is 120/80 Blood Pressure at Lying position Notmal or high? [closed]

I was suffering from Anxiety and GAD for last 18 months. I used to have BP Shoot ups and it used to go till 170/105. Now I try to keep my mind Calm and I am trying to quit the medicine Xepar/...
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2answers
1k views

How does Bernoulli’s Principle apply to the cardiovascular system?

Below are graphs which illustrate the cross-sectional area, velocity, and fluid pressure through each vascular segment of the cardiovascular system. It makes sense that velocity and cross-sectional ...
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3answers
4k views

What does irregular heartbeat mean in simple language?

I bought a blood pressure monitor (A&D UA-851) which has the option to measure irregular heartbeat. I do understand what 'irregular' means, but why do irregular heartbeats happen and what are it'...
2
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2answers
158 views

What is the effect of persistent hypothermia on cardiac performance?

I define persistent hypothermia in this thread about the mechanisms of persistent hypothermia. The Graph of Katzung et al. in Pharmacology about Heart Failure: I am thinking which parts here are ...
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1answer
88 views

Why is heart failure treated as more critical than kidney failure?

The heart pumps the blood to supply tissues and kidney always filters the blood to remove urea,extra water and etc. And all these are vital,so the kidney is as important as heart: and my question is: ...
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8 views

Placental Adherence and Premature Heartbeat

I am studying the placental adherence in premature fetuses i.e. from 22nd week to 38th week of gestational age. About 60% of placental adherences are diagnosed during labour, which increases the risk ...
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29 views

What is the function of the Moderator band?

The moderator band in the right ventricle is a band sorts of muscle which consists of a significant branch of the AV bundle. Does it mean it delivers impulses to the anterior papillary muscle faster? ...
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24 views

Determination of Ageing by ECG inclusions/exclusions?

I am studying ageing and considering ECG signal because of its high sensitivity in theory (escardio). Some factors Sensitivity Gender Medical treatment ... Benchmark: RTG dental + wrist ...
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17 views

ECG Calibration by Infusion Pump?

I am trying to understand how to calibrate 5-lead ECG device with an infusion pump before the human calibration as described here. The system uses 5 electrodes (RA, RL, LA, LL and Chest). The monitor ...
2
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1answer
80 views

Is blood pressure in the aorta and brachial artery the same or different?

Does the blood pressure at the root of aorta equal the blood pressure in the brachial artery? I've heard it does, but it doesn't quite seem to make sense as I'd think the blood pressure would be ...
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18 views

What is the realationship between arterial pressure and stroke volume

Frank-Starling Law says , When keep const Pvp (pulmonary venous pressure) and T ( heart period) and we increase Psa(aortic pressure or arterial pressure), Vd(end-diastolic volume) and Vr(residual ...
3
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1answer
168 views

How does sepsis affect heart function?

I have intuition that sepsis with infection can cause: spastic functioning of heart during systole heart working spontaneously in snatches during systole atrial fibrillation first contraction of ...
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1answer
94 views
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15 views

How can hyperplasia occur in non-fetal hypokinesis?

I have read that the hypoplasia can occur in fetal hypertrophic cardiomyocytes. However, I am interested if this can be theoretically be possible in non-fetal cardiomyocytes which are hypokinetic. I ...
2
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1answer
5k views

How do inward rectifier potassium channels work in the heart?

Apparently in cardiomyocytes, there is an inward rectifying potassium channel that operates during phase 4 of the cardiomyocyte action potential. I have heard that despite this potassium channel ...
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1answer
140 views

Cancer in myogenic heart cells? [duplicate]

Why cancer does not occur in myogenic heart cells? Is there any special ability in heart cells to resist cancer ?
3
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72 views

Persistent HPV and CVD in Women?

Cardiovascular disease is the number one morbidity factor of women. I am studying the relationship between persistent HPV infection and CVD (Cardiovascular Disease) in inadequate immune responses. ...
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3answers
9k views

Why is defibrillation in asystole (“flat line”) useless?

In most popular medical dramas, when a patient has a cardiac arrest and "flatlines" the doctors many times use a defibrillator to "shock the heart back into rhythm'. I know that actually, the proper ...
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13 views

Membrane conductance in phase 1 of the cardiac action potential

Correct me if I am wrong, but in phase 1 of the cardiac action potential (for ventricle cells) there is flow of potassium ions due to the opening of transdent potassium channels. To me this would ...
2
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1answer
36 views

How are cardiac cells stimulated by an action potential?

Why, and how, does the action potential of one cell in the heart stimulate an action potential in the next cell? I'm interested in an answer with citation.
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63 views

What does the term pre potential mean in the pacemaker cells of the heart?

I recently read about the concept of the pacemaker potential in the heart . In this what does the term pre potential refer to ? Is it the same as the pacemaker potential. This is because one of the ...
2
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55 views

Why is there a structural difference between the bicuspid and tricuspid valve?

There are three cusps in the tricuspid valve and only two in the bicuspid valve? Why is there such a structural difference? Does it have anything to do with that there is oxygenated blood on the left ...
2
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1answer
2k views

How long do the periods of systole and diastole last?

The background to this is i'm doing some work using ECGs for an animation of the heart and i'm having trouble defining the end points of these periods, particularly diastole. Currently, the only ...
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6 views

How much potential from heart reaches the chest

I learn about the ECG waveform of heart potential.How much voltage will actually reach our skin which is developed in the heart(from Sinoatrial node).What will be the approximate voltage range when it ...
5
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1answer
438 views

How can heart disease cause dizziness after eating?

I have been reading several articles explaining dizziness after eating (see here and here), and both articles gloss over something that I found pretty remarkable. Both articles claim that "heart ...
2
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2answers
8k views

Why there is a very high drop in pressure from arteries to arterioles?

Laplace law explains why the pressure is the same in aorta and arteries (100). I am thinking why there is so big drop in pressure when going from arteries to arterioles (40-60). Why there is a great ...
2
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0answers
106 views

Why do earthworms have 4 hearts?

I was reading about earthworms and came to know that they have 4 hearts. Why is there a need for a 4 heart system? What advantages would it have over a 1 heart circulatory system except for pumping ...
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78 views

Reasons for strange heart rate graph following exercise (line going up and down)?

Following a 2 minute general jumping and movement exercise designed to involve the entire body, the pulse was taken every minute for ten seconds. Strangely, the graph appears to jump up and down, for ...
5
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1answer
133 views

Normal ECG/EKG Measurement?

I'm getting started using ECG using a 3 lead system by iWorx. I have place the leads on my two wrists and the ground on my ankle and have recorded some data into the provided LabScribe 3 software ...
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0answers
61 views

Can bigger persons generally resist g-forces better?

I've seen a claim that bigger persons generally resist g-forces worse than smaller in an undergraduate biology book. However this claim was supported by the argument that blood has to travel a longer ...
3
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1answer
166 views

Explanation of ECG in MI using an electrostatic model

I found a paper presenting an electrostatic model to explain the ECG recorded in various leads. This model essentially calls for considering the depolarization wavefront to be the major contributing ...
2
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1answer
54 views

Physiology of tricuspid and bicuspid(mitral) valves

The tricuspid and bicuspid valves are atrioventricular valves. Both are valves that prevent backflow of blood pumped from the atria to the ventricles. However, the former has 3 "flaps" while the ...
2
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1answer
182 views

Does our heart stop when we sneeze?

Is it fact or myth that our heart stops beating for moments when we sneeze? If it is fact, what drives the heart to start beating again?