Questions tagged [cardiology]
the branch of medicine that deals with diseases and abnormalities of the heart.
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How common is tachycardia as a symptom of COVID-19?
How common is tachycardia as a symptom of current COVID-19 infection? I have found quite a bit of information about tachycardia after COVID, such as this paper and this Cleveland Clinic article, but ...
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ECG: vector perpendicular to lead axis and its pattern
I have come across a contradiction while learning about ECG.
Some sources say that a biphasic deflection (two waves of same size but of opposite directions) is drawn on ECG tracing if the electrical ...
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Why is there a rapid ejection phase followed by a slow ejection phase in isotonic contraction, why isnt this a steady rate?
Trying to work our how the cardiac cycle works by gaining a deep understanding, would appreciate any explanations which go into such depth and what variations we may see if this was a pathological ...
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What limits the VO2 (rate of oxygen consumption) in individuals?
I am quite confused regarding what limits the VO2 max, options are (1) number of mitochondria or (2) the ability of the cardiovascular system to deliver oxygen to tissues.
I believe it should be the # ...
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How does blood flow change between systolic and diastolic phases?
Summary
What is the change in flow between systolic and diastolic phases specifically in the muscular arteries? There is a lot of information on how pressure changes between these phases (see graph) ...
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Does an increased heart rate from stimulants train the heart as if the increase came from exercise?
Bottom line it will probably be unhealthy - but if the effect on heart fitness is viewed in isolation?
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Should we invert other ECG leads if aVR was positive?
I would like to seek your kind guidance in understanding the right way of solving this question. (for the context, so far we only covered normal ECG and axis deviation)
The question displays all 12 ...
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How to determine QRS voltage from ECG?
Attached below is a question from my textbook "Guyton and Hall Textbook of Medical Physiology Review, 4e" and I am confused because the solutions manual has the answer as B (0.5mV), implying ...
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Why are some guidewire's tips bend for endovascular interventions?
I am working in a medical-physics field and want to summarize some information about guidewires. I have read, that guidewires can sometimes have their tip bend slightly in one direction, in order for ...
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Are there any recent studies of the incidence of atrioesophageal fistula as a complication of cryoballon ablation for afib?
I have found some reports online after searching and although the paper is 2018 the studies referenced may actually be considerably older and the technique may have been improved since then.
Surely I ...
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Pressure volume curve; Is it wrong ESPVR?
ESPVR is a straight line passing through the upper left corner point of the pressure volume curve and such that the x-intercept is the dead volume of the ventricle; as far as this definition is ...
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What is the difference between the vasomotor center and cardiovascular center in the brain?
The vasomotor center is introduced as the following in our coursework:
The vasomotor center is located bilaterally in the reticular substance of the medulla and lower third of pons. It contains the ...
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How is adding up action potentials equivalent to measuring the direction of depolarization vectors?
An ECG of the heart measured from lead II looks like this:
I have seen two ways of arriving at this image, the first is by considering the depolarization and the repolarization vectors and their ...
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Why doesn't water enter the venous system if injury happens far underwater?
If I expect a maximum central venous pressure of 5 mmHg in a peripheral vein, why doesn't water enter the system if a diver underwater injures themself?
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Myocardial infarction treatment [closed]
During a myocardial infarction, as an immediate treatment, we must try to decrease the workload of the heart so that it will not require the extra oxygen that it would need and cannot get due to the ...
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CAR-T therapy for cardiac sarcoidosis?
Do you know whether CAR-T therapy to replace fibrotic cells in the heart might apply to scarring from cardiac sarcoidosis?
The articles below are from Penn research that shows they are able to replace ...
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EKG reading question [closed]
Can someone tell me what "ETRSR1-RSR' in V1 or V2, right VCD or RVH-QRS area positive & R' V1/V2 " means? In other comments it also said "otherwise normal EKG"
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What happens to cations after depolarization/repolarization in cardiac muscle?
In the depolarization/repolarization of the cardiac cell cations such as sodium, calcium, and potassium flow in and out of the cell creating an action potential. My question is what happens to these ...
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Cardiac events/Myocardial infarction from 1 clinic or 1 large city daily data
Requesting help in finding a DAILY data about cardiac events/myocardial infarction from 1 clinic or 1 large city, i.e. day by day number of events for at least a month.
It is very easy to find this ...
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Cardiopulmonary capacity assessment
Is it possible to determine someone's cardiopulmonary capacity from organ/tissue/blood samples alone?
No other clues allowed. Think about a non cooperative patient, who can lie in an anamnesis, or ...
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How does a cardiopulmonary bypass machine continue circulation without cutting off circulation to the pulmonary veins and artery?
So, my first stop in trying to answer this question was on Johns Hopkins website, but they are way too vague about the procedure, especially the use of a cardiopulmonary bypass machine. The only ...
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Phases of cardiac cycle
what is the correct sequence for cardiac cycle
Sequence 1: a. Atrial systole b. Ventricular systole c. Combined diastole
Sequence2 a. Atrial systole/Ventricular diastole b. Ventricular systole/atrial ...
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How does a prosthetic heart valve "burst"?
I have a friend who's father died suddenly, and the coroner described the cause as his prosthetic heart valve "bursting." Can someone illustrate in words what that means, and would heart ...
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How do I measure my resting heart rate?
I measured my sitting down, relaxed, not moving heart rate, which is around 65-80BPM.
If I do the same measurement laying down, it's anywhere from 50-65BPM. While asleep, it dips into the 40s.
The ...
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Why in Brockenbrough-Braunwald-Morrow there is a paradoxical decrease in arterial pulse pressure?
The article here tells that in HCM due to ventricular premature contraction there is enough time for dilatation of ventricular filling which increases end diastolic volume thereby increasing ...
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Bradyarrhythmia & Bradycardia- same or different?
Do Bradyarrhythmia & Bradycardia denote same abnormality or are there some finer differences between the two?? In text provided by my college, it appears bradycardia condition comes under the ...
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Why does LDH-1 peak later than CK-MB in acute myocardial infarction?
As a marker of AMI, different enzymes are used. Creatine Kinase-MB peaks within 24 hrs and returns to normal relatively quickly. Where as LDH-1 peak appears later (~72 hrs) and stays high for a week.
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Bulbus aortae is a part of aortic root, then where are the two measurements taken?
I would like to clarify my understanding because anatomy atlases do not provide me an explanation. As far as I know, the aortic bulbus is a part (the widest, the sinuses of Valsalva) of the aortic ...
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Could an increase in heart strength result in an increase in systolic blood pressure? [closed]
If someone begins intense cardio training and develops their heart muscle, it seems to me that the increase in volume of blood that the heart can pump with every beat might manifest as a higher ...
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What does primary, secondary and safety outcome of a drug study mean?
I was reading a research article and came across this:
We studied 55 outcomes of interest, including both effectiveness and safety endpoints. We divided effectiveness outcomes into three primary ...
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Why can't JVP be measured in a standing or supine position?
While carrying out the jugular venous pressure (JVP) examination, the patient is kept at a 45 degree angle with respect to the ground. Why can't it be measured in a standing or supine position?
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How to differentiate Split S2 from Mitral valve prolapse murmur?
If history is not available or doesn't gives a clue about the pathology, is it still possible to tell whether it is MVP or Split S2 due to pulmonary valve problems?
Both split S2 and MVP's murmur( the ...
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Can I calculate the blood pressure and pulse based on a given blood loss
Is there a function, graph, guideline or rule where I can see how a change in blood volume changes other relevant values?
E. g. for every 1% of blood volume lost, heart rate rises 2 beats per minute, ...
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What does NKX2-5 do?
Where is the gene 'NKX2-5' located and what is its function? How is it relevant to developmental disorders?
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Why do semilunar valves not need tendinae but atrioventricular valves do?
Inside the heart the atrioventricular valves (AV) have chordae tendineae to prevent the backflow of blood into the atrium when the ventricle contracts.
Since the AV and semilunar valves are ...
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Should people with tachycardia avoid choline supplements?
After doing some brief research online it appears choline can have an effect on the electrical system of the heart, there are several medical papers online that discuss this topic, however I'm not ...
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Does COVID-19 cause myocardial infarctions?
I heard that NYC hospitals are seeing an increased cases of myocardial infarction with higher mortality than normal during this COVID-19 pandemic. What the connection is between COVID-19 and ...
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Can aortic stenosis lead to arrhythmia?
As I understand, Aortic stenosis restricts the blood flow from the left ventricle to the aorta, this restriction should cause a disruption in the pumping of blood. That would cause the heart to beat ...
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Beginner runner/jogger heart rate question [closed]
I am an it guy 220 lbs 6ft1 35 years old. With chest strap measurement my maximum heart rate is around 192 bpm. (Did warmup and 3 minutes thread mill intervals to measure)
For a long period of time, ...
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Why do changes in Effective Refractory Period in Response to Antiarrhytmics occur and how do they help in treating the arrhythmia?
I am having trouble understanding two related concepts. First, why changes in ERP occur when there is the administration of certain antiarrhythmics (eg: Class IC). A neat explanation that I have ...
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Difference in heart muscle tissue growth (cardio vs low-rep intense weight lifting)
Below is a quote from a subreddit that says:
I haven't kept up on the research, but the last thing I read back in college looked at weight lifters and long distance runners. Both types had larger ...
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What is the functional difference between cardio-pulmonary and the baroreceptors in the regulation of Blood pressure?
Guyton mentions two types of receptor- the baroreceptors and the cardiopulmonary receptors- that are involved in the maintenance of the acute changes in blood pressure. I just wanted to know how these ...
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What causes a notch in the atrial pressure?
I wanted to know why there is a sort of fluctuation in "E" in the tracing of the atrial pressure right before the mitral valve opens (not the notch because of the Aortic valve closure).
Source for ...
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Heart Sound Samples
Does anybody have helpful sources/links that are basically recordings and playbacks of heart sounds (normal/ abnormal/ etc.) that I could just listen to while in my spare time? I am looking for ...
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Do cardiologists learn nutrition as part of their expertise in Cardiology?
Almost all physicians I recognized as suggesting medicinal nutrition either as direct therapy, preventive medicine and via "popular medicine" as with books and articles, were Cardiologists; to a ...
user8225
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Ventricular diastolic pressure?
So, I have been wondering and couldn't find texts explaining this, but why is the diastolic volume of the circulation ~80, while that of the ventricles is almost 0. To phrase it another way, why does ...
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Are defibrillator leads actually clashed against each other?
In movies or television, the doctor gets giant heavy clothing iron sized leads. Clashes them together and uses them on the patient that has a flat lined heart and after doing it 1 times per second ...
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Acceptable Macronutrient Distribution Range [closed]
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2674146/
I found some papers suggesting AMDR is not the optimum and it is too high on carbohydrates in particular.
Is it generally safe to undergo a
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How to assess the risk of "cardiac event" for a healthy runner? [closed]
It appears to be dreadfully not uncommon that seemingly healthy people suddenly die of "cardiac events" when doing physical exercises. Here is just another sad example: a healthy and regularly running ...
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Difference between acyanotic and cyanotic
Recently I have been watching khan academy videos on acyanotic and cyanotic diseases. I know that acyanotic means not blue and cyanotic blue. Because I still can not understand the difference between ...
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