In an EKG why does the chest leads (V1-V6) does V1 have a sharp drop in the negative direction?
150174
The EKG estimates the net vector (in two dimensions) of the electrical activity of the heart; from the direction that the V1 lead looks (Above and to the right of the heart, as I recall laying out the electrodes years ago), the electrical activity is going away from the lead--towards the feet, or in the QRS part (the really big deflection), it's going from the AV node toward the tip of the ventricles.  That would be read as a negative direction.\n\nRemember, at every instant in time, the EKG is recording the equivalent of the dot product between the actual vector of the flow of current (so to speak) in the heart, and a vector that is created by connecting the leads in question.  For the V1 lead (a precordial lead), the leads connected to the limbs are used as a single lead, sort of grounding things out between all four of them (think of it being a lead somewhere behind the belly button, if you want), and then measuring the dot product of the electrical vector and a line connecting the V1 position with that.\n\nA little vector algebra makes this a LOT easier!
260861
Think of the analogy between the flow of electricity and water where voltage is pressure and current is water flow.  It take voltage (pressure) to cause current (water flow).  Therefore, current (water flow) will occur in the direction under greatest voltage differential (pressure).  Because you may be working with more than one voltage source (two transformers or ttwo battery cells?) one of the sources may be adversely affected.  Are you working with AC or DC?  You may need to avoid connecting a circuit for example that would be like charging a car battery with the leads reversed.  Good luck.
1121457
sinusoidal is a refrence to the sine curve.  \na sine curve, when graphed, fluxuates up and down- like a wave at sea.\nAC current fluxuates between a posative and negative charge.\ntherefore, when its charge is graphed you get a curve.  HOWEVER, THIS ISNOT A SINE CURVE.\nbecause the shifts in polarity are nearly instantaneous-and polarity is either posative or negative (no partial this or that)- the graph looks like a bunch of squares. That is, a verticle line up, horizontal line over, verticle line down, a second horizontal line over (below the first).\nbut for all intents and purposes, the curve can be called sinusoidal, so yes the current in the wire is sinusoidal in respect to its alternating polarity.
324898
I do not have any personal experience as far as one of my children or family members with SVT, but I perform EKGs everyday on everyone at my hospital including babies.  Typically rhythm problems are sporadic to say the least.  The general belief is that when a child has a rhythm problem it will subside later in development and medication should cease the episodes at an early age.  You should expect to see more episodes and lots of other medication.  Typically when a patient has rhythm abnormalities, initial medication fixes the problem but for some reason you see a recurrence of the abnormal rhythm and is fixed again with another medication.  Strangest thing...happens all the time.  Don't know why, and quite honestly I don't think many doctors know why.  Typically it's a problem you learn to monitor and deal with as an episode occurs.  Just give it time though, he may grow out of it when everything begins to develop along further.  Sorry I couldn't be more help
746423
If from left to right gets bigger or more positive, and from down to up gets bigger or more positive regarding numeric values, then it makes sense to label the quadrants in that manner.  You start with all positive values in the first quadrant.  Then y values are positive and x values are negative in the second.  Then all values are negative in the third.  Last, y values are negative and x values are positive.\nThe assumption is that x is on the horizontal axis and y is on the vertical axis.
392559
alright instead of a long docter explanation, its a shortage of breath and your chest when trying to regain breath its kinda like a positive negative reaction. they suck but if u loose breath again and slowly come back to breathing normal youll be fine.
962570
It will flow in either direction if the voltage is above 0.7 volts
129691
See my answer to your next question.  For phase lead, C is in series and R in shunt.
732303
The ECG is a very good study but it has many limitations.  It is very reliable at detecting problems that interrupt or change the electrical energy paths through your heart.  The heart has two major systems though - the pumbing and the electricity.  Sometimes one systems affects the other but sometimes not, too.  There are plenty of true heart attacks, for instance, that demonstrate no or very little change on the ECG.  As well there are plenty of benign conditions that change the electricity (from "normal") and turn out to be nothing more than a congenital malformation in the way a person's heart works.  Finally ECG's are a moment in time - they are very poor at predicting what might happen in the future.\n\nIn short, just because you had a normal or abnormal ECG, it may or may not mean anything and it certainly doesn't tell you what might happen tomorrow.  It needs to be assessed in context of other markers or symptoms.
22027
In case you are asking about a current versus potential difference plot, the slope at any point (or he reciprocal of it, depending on what you plot on the y-axis and on the x-axis) gives you the dynamic resistance there.
107334
This question needs a little work. By convention, current flows from + to - although in real life, current is electrons which go from - to +. But only physics types do it that way. Electrical engineers say + -> -.\n\nNow, that being said, if you have a non-zero resistance across a voltage source, you can find the current flow by measuing the voltage across the load (resistance). The lower  the resistance, the lower your voltmeter has to read. The sign of the voltage would indicate the current flow. \n\nSo say you have a 10V battery and two 5 ohm resistors in series across it. The total current will be 1A (ohm's law). Now if I measure the voltage across one resistor, I should read 5V (kirchoff's law by the way) and the sign (+ or - 5V) will tell me the current direction. Using conventional + to - flow, if the voltage is + the current is flowing from the red lead to the black lead.
774945
It is the line connecting Vcc/Rl and Vmax on the transistor VIcharecteristics V on the x axis and I on the Y axis. Where it cuts the charecteristics we get the quiscent point or the operating point. This is the mean point,  the output current varies sinusoid beyond and below this point on the load line.
461189
Also known as SVTs, it describes a very rapid heart rate. It would be helpful to know the underlying rhythm (ie: atrial flutter, atrial tachycardia, etc...) If you find out, post this question again. It would be helpful to know a few other things about you, so I'll have to give a broad answer. The heart is unique tissue that beats when it receives electrical impulses (you may have seen actors who pose as "dead patients" on t.v. get "shocked" in the ER with electricity to help their hearts beat again). With SVTs, a part of your heart gets "excited" and starts to shoot off it's own electrical impulses, which can cause the heart to beat out of rhythm, and very fast. You should see a cardiologist and have a few tests such as a 12-Lead EKG, 2d echo, holter monitor, blood & thyroid tests, and possibly a stress test. Many young females get SVTs, which is usually harmless and do not cause any longterm problems. These cases can be treated with simple lifestyle modifications that can minimize attacks (such as sleeping better, reducing stress and eliminating caffeine products). Patients can do Valsalva manuevers to stop SVTs. As far as alternative, homeopathic, etc... there are no products that have shown evidence in successfully treating SVTs. If you ever find that your SVTs won't stop, you may get dizzy, get chest pain and your cardiac output will fall and you can pass out. Have someone dip your face/head in a bucket of ice-cold water (the mammalian diving reflex) and call 911. Medications, ablation, cardioversion, etc... are reserved for advanced cases. These patients may be older or have other cardiac issues going on. Or they can get SVTs before or after a heart attack due to changes that occurs in a part of the heart called the "Atrium". I hope I was able to answer some of your questions...
17953
In AC circuits,  actually current                   in inductors and capacitors,waveform is not in phase with voltage(You will study it later).The factor "i" ,multiplied to any vector rotates it through 90 degree in anti clockwise direction.Thus we get a mathematical technique to solve the circuit
574352
A low-voltage (110 to 220 V), 60-Hz AC current traveling through the chest for a fraction of a second may induce ventricular fibrillation at currents as low as 60mA. With DC, 300 to 500 mA is required. If the current has a direct pathway to the heart (e.g., via a cardiac catheter or other electrodes), a much lower current of less than 1 mA, (AC or DC) can cause fibrillation. Fibrillations are usually lethal because all the heart muscle cells move independently. Above 200mA, muscle contractions are so strong that the heart muscles cannot move at all.
329507
I imagine what you mean is that, if temperature goes from higher to lower the "delta T", or change in temperature, is negative. If it goes from lower to higher, the "delta T" is positive
379605
A first degree heart block, or av block, is a conduction problem between the atrium (a) and the ventricle (v) of the heart. This is diagnosed by EKG reading with a PR interval greater than 0.20. \n\nOn a basic level: The electric impulses in your heart is hitting a "yield sign" on a straight away.