Tachycardia, MVP

I am very confused and need an opinion. I was having episodes of a rapid heart beat around 160-180 that would only last a few minutes on and off for 3 years. I had every test done possible and was told it is only sinus tachycardia. They did an echo expecting to find Mitral Valve Prolapse but my cardiologist said I did NOT have it. He said my valve was elongated but without prolapse but with trace regurgitation. This is my first question....If I have trace regurgitation would that have to mean I have MVP and maybe he is wrong? I also had an echo done a year before which showed nothing.
I was told the things I feel are anxiety. I have become very focused on my heart and seem to feel every beat sometimes. I dont know if I  am feeling it so much because of my focus and worry OR do I focus on it because there is something wrong and that is why I always feel it.
I went to a second cardiologist who did not do any testing just listened to my heart and he seems to think I do have MVP because he heard a clicking. The first DR also heard this clicking because I was nervous and my heart was so fast but said the echo showed no MVP.  My second question is : If I do a third echo to look for MVP  can it just show up now or is it something you are born with and would have showed up in the first two echos?
I also have Holter results that I dont understand: ST Depression Ch1 0 episodes, Ch2 5 episodes max-2.7mm and Ch3 8 episodesmax-2.4mm. Can you please tell me what that means.
The finding were, Sinus tach/Sinus arrythmia---- I know what sinus tach is but is sinus arrythmia DANGEROUS and what is the difference.
Rare single PAC"s only
Symptoms did not correlate with any arrythmia other than sinus tach
No significant ST depression.----how is that when I had episodes 5times and 8 times as stated above?

Sorry for asking so many questions but I need to put my mind at ease so I can stop worrying about what my heart is doing all the time. I look foward to your response. Thank You Jean

[CCF-M.D.-CRC]

Dear Jean,
It is possible to have regurgitation without prolapse although prolapse is a common cause of regurgitation. If there was no MVP shown on the first 2 echos it is unlikely that it would show on a third echo.  Even if it did I'm not sure it would change treatment for you all that much. The Holter monitor results are describing changes in a portion of the ECG called the ST-segment.  This segment is often used to diagnose coronary artery disease but in your case would have less significance. Sinus arrhythmia is normal and refers to the variation in heart cycles. Hope this helps to put your mind more at ease.

[Mike501]

ST SEGMENT DEPRESSION INDICATES LOW OXYGEN TO THE HEART MUSCLE.
IT CAN BE CAUSED BY 3 THINGS MAINLY :CORONARY  DISEASE , BY A LEAKY VALVE AND BY INFECTIONS OF THE HEART MUSCLE.
AN INCREMENT OF THE ST SEGMENT DENOTES PERMANENT HEAR MUSCLE -INFARCTION.
THE FACT THAT YOU WHERE NOT DIAGNOSED WITH MVP DOES NOT MEAN THAT
YOU DONT HAVE IT .IT DEPENDS GREAAAATLY ON THE SKILL OF THE
ECHO TECH DOCTOR WHO DOES YOUR ECHO IF HE OR SHE CAN CATCH UP THE MOMENT WHEN YOUR VALVE BACKS UP.
HOPE THIS HELPS.
PS YOU MIGHT CONSIDER GOING THROUGH A TEE ECHO WHICH WHILL SHOW
MORE DETAILS OF YOUR HEART +VALVES.