Ventricular tachycardia vs. Left bundle branch block?
During a stress test i got misdiagnosed. The 2 nurses present thought i was in VT but really was a LBBB(which they kind of scared me!) How often does that misdiagnoses happen?
Can a stress test confirm that blockage in the arteries is NOT present?
Also can a LBBB make a stress test inconclusive regarding blockage during a stress test?
How common is LBBB?
- AgnodiceLv 71 decade agoFavorite Answer
If someone has proper training in the interpretation of an EKG, then they should NEVER confuse ventricular tachycardia or left bundle branch block. They are very easily distinguished from each other by looking at the appearance in different leads. Untrained individuals may easily confuse V. Tach and LBBB, because they are both associated with a wide QRS complex.
First, stress tests detect significant blockages in the arteries that supply the heart. It is possible to have small, non-significant blockages (blockage < 30%) and have a normal stress test. These blockages are likely to not have clinical symptoms and may not ever lead to any problems. The results of the stress test are dependent on your pretest probability of having heart disease, which is the likelihood that you have heart disease. If someone is young and healthy with no risk factors for heart disease, then they would have a low pretest probability of heart disease. If this is the case, then a normal stress test then the likelihood that you will have a heart attack or other cardiac event in the next few years is virtually zero. If you have classic symptoms of heart disease and multiple risk factors, then you would have a high pretest probability. If this is the case, then a negative stress test is not helpful, because the doctor's suspicion is still high. For this reason, stress test should be avoided in most patients with high pretest probability of coronary artery disease and they should proceed to cardiac catheterization where the vessels are directly visualized. Intermediate pretest probability is a risk between high and low, and stress test is most useful in this case. The results of the stress test should be interpreted with the person's risk factors in mind. Sorry to go through all that, but I just wanted to point out it is more complicated and not just black or white. I do not know your risk factors or likelihood of heart disease in your case. It also depends on the type of stress test (Exercise vs. Chemical) and whether imaging (Echocardiogram or Nuclear imaging) was used. Exercise stress tests are the best for predicting the likelihood of death from heart disease. If you can complete the Bruce Protocol on exercise (treadmill) stress testing, then the likelihood that you have significant heart disease is low and your chance of death from heart disease in the next year is very low. Imaging improves the results of the stress test.
LBBB interfere with the EKG interpretation of a stress test, because it is associated with changes in the ST segments and T waves which are what is analyzed during the stress. Therefore imaging with Echocardiogram or Nuclear imaging is required for stress tests in a person with LBBB. LBBB is not uncommon. The incidence of LBBB increases with age. In a study of Swedish men, the incidence was 0.4 percent at age 50, 2.3 percent by age 75, and 5.7 percent by age 80. LBBB in young individuals is usually not associated with an underlying condition. In older people it can be related to underlying heart conditions or degeneration of the conduction pathways of the heart with age.Source(s): Physician
- 1 decade ago
LBBB should not confuse with VT.Because in LBBB the impulse is supper ventricle and should show P WAVE and VT impulse is start in ventricle and will not see P wave(or cover by V activity)VT is fast rhyme and LBBB is not,unless SVTC.Both has widen QRS complex(more then 0.1 second) and may have ST change.LBBB is due to the pathway go to L ventricle is block(due to degeneration or damage during MI).The impulse reach to L ventricle is much delay and result of abnormal EKG.This is pretty common due to arteriosclerosis of the heart.Blockage of the artery and blockage of the pathway is two thing but may related.Stress test positive for ASHD is ST change when in exercise that mean not enough oxygen to supply to the heart muscles.Yes, since positive ASHD and LBBB both show ST change some time may differcult to make the diagnosis.
- Anonymous1 decade ago
LBBB's are fairly common and often people never know they have them. It can make reading the EKG a bit inconclusive. For a better study you should have a nuclear cardiac stress test.
Basically they take pictures before and after your stress.
It is common for people who are inexperienced to confuse a VT and LBBB.
Basically I wouldn't worry about the LBBB. If you went for a good amount of time on the treadmill with no chest discomfort and no abnormal shortness of breath you are probably in the clear with a blockage, but the best diagnostic tool we have short of cathing you is the nuclear imaging portion of a stress test.Source(s): Paramedic and Cardiac Stress Technician.
- IreneLv 44 years ago
No and no. Once your heart is enlarged, it doesn't go back to normal. A right bundle branch block is benign and someone can live a productive life with it. If this person has these problems, blood pressure medicines might be the only choice along with dietary changes and exercise. If the left side of the heart is enlarged (depending on how bad it is), the heart has a difficult time pumping the blood. Left sided heart problems causes issues with the lungs, such as congestion and or pulmonary edema. Just be careful. Watch the salt intake. Best wishes.
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- 3 years ago
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