Questions tagged [electrocardiogram]

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30 views

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 ...
1 vote
57 views

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 ...
90 views

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 ...
32 views

How to determine the "argument" of the electrical axis of the ECG from aVF ＆ VI

This question is a continuation of the following question; Is the definition of aVF consistent with Novosel’s formula? Unfortunately, the article at the following URL is written in Japanese, but its ...
57 views

Is the definition of aVF consistent with Novosel’s formula?

"In regards to the electrocardiogram, there is often a Statement made that, 'The a' in aVF means 'augmented' by a factor of 1.5 for sensitivity adjustment. If the above statement is true, ...
1 vote
14 views

On an ECG, do we take the J point to be the baseline or the TP segment?

I'm studying current of injuries and the diastolic current theory is explained as such: The ECG machine is programmed to keep the T-P segment at baseline with everything else on the strip moved up or ...
53 views

Difference between strength and hypertrophy?

Doctors tell us to do lots of cardio exercise to "strengthen" the heart. Then some people get hypertrophy (another form of heart muscle growth) and it's considered "abnormal" (even ...
1 vote
57 views

I am new to this and I am trying to do some filtering on ECG signals. I am working on Lead I signals but they appear too noisy. However, Lead II singals appear significantly less noisy whilst having ...
45 views

Is this a P-wave on single-lead ECG

I am an engineer working on a project using ECGs. I am trying a few techniques and I was wondering whether the P-wave is still visible in the ECG after filtering it. The issue is that I believe the ...
80 views

46 views

Reason for ecg volume conduction waveform?

Can somebody for the love of humanity and genuine curiosity explain why does the voltage between 2 oppositely charged ends of a progressively depolarizing cell peak when the wave reaches the middle ...
1 vote
94 views

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"
1 vote
68 views

Estimation of QT interval when T and P waves overlap

On an ECG (EKG) machine, in a normal Sinus rhythum (with well distinguished T waves), the interval between the start of the QRS complex and the end of the T wave, (i.e. QT interval), can be estimated ...
85 views

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 ...
54 views

PR depressions on ECG when a patient has pericarditis

Can someone please explain why PR depressions are seen on an ECG when a patient has pericarditis? That is, from an electrophysiological perspective: What are the exact changes on the cell membrane ...
39 views

Is the voltage at the heart the same as in limbs for ECGs?

When doing an ECG we measure the electrical voltage between two points on a person's skin (for example for Lead II it's right arm and left leg). I am confused as to how the heart's potential ...
186 views

What heart condition(s) cause tingling and lightheadedness that are NOT caught by an ECG?

Please note: A lot of things cause tingling in the face + extremities ("neuropathy") as well as lightheadedness, but in this question, I'm only interested in potential heart conditions, or anything ...
103 views

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 ...
1 vote
19 views

What would the graph look like if the electrodes were non-equidistant from the depolarization wave?

Hypothetically speaking using the diagram above. If the negative electrode was very far away from this cardiomyocyte and the positive electrode was right next to it. What would the voltage graph look ...
162 views

Positive deflection of an ECG

I understand that the voltage will be positive as measured by the ECG but I was wondering why the voltage reaches a maximum exactly at the midpoint. Is there a physiological reason (like sodium ...
54 views

4 Electrode vs 5 Electrode ECG [closed]

I see that in a 4 electrode ECG (LA, RA, LL, RL) we can measure upto 6 Leads (LeadI, LeadII, LeadIII, AvR, AvL, AvF). What increase in value does adding an additional chest electrode like V2 provide? ...
31 views

Looking for an ECG anomaly detection tool

In a few months I will be conducting a study where we take participents ECGs and try to measure stress levels from that using machine learning. I am also involved in pre-processing the data, meaning ...
88 views

Does a wave of depolarization towards a positive electrode always result in positive deflection on ECG? [closed]

Pretty much what the text says. For the sake of simplicity let's imagine we have this scenario here: https://www.google.com/search?q=ecg+guyton+and+hall&tbm=isch&ved=...
15 views

Standards for Electrocardiography and Photoplethysmography

Electrocardiography and Photoplethysmography are two techniques/devices that are commonly used to measure heart rate. My question is, clinically speaking, what are the standards these devices must ...
1 vote
46 views

How wrist wearables count breaths?

I am doing a research about wrist wearables in order to understand how they work. They can be used to measure stress levels, just like pupillometry, skin conductance and other related measures can be. ...
1 vote
23 views

What is the significance of the right lower node in a 12-lead electrocardiogram placement?

Given this EKG limb leads image, I noticed that the function of the right leg node in a 12-lead ecg/ekg is missing. In an actual placement I know this is present. So I need to ask, what is the ...