Echocardiography is an imaging tool . Can it be used as a non invasive EP lab ?
Heart is an electromechanical organ . For every mechanical activity there must be a electrical event preceding it . So, when we analyse the cardiac contraction and relaxation it indirectly provide us clues how the electrical activity spreads across the heart.
The concept of using echocardiography for diagnosing cardiac arrhythmias have never been popular for the simple reason we have a cheap and best modality : The ECG. But, it does not give us the temporal relationship with the cardiac contraction. When these two are combined it can be a really powerful tool to analyse many cardiac arrhythmia.
- In fact , for every brady and tachyarrhythmia there has to be an unique pattern of IVS motion and mitral , tricuspid valve movement.
- Almost all bradycadias can be diagnosed with echocardiogram by virtue of analysing the timing of atrial vs ventricular contraction.
- We know echocardiogaphy is the only modality available to diagnose fetal cadiac arrhythmias.* (How can this modality becomes useless when the baby comes out of the mother’s womb !)
- Apart from this there is an unique use for echocardiography to locate accessory pathway in WPW syndrome
The premature contraction of LV can be seen in few as an early systolic dip in IVS movement -Type B WPW.
Image courtesy : Helmut F. Kuecherer Circulation 1992;85:130-142
Abnormal jerky movement of LVPW indicate left accessory pathway -Type A WPW
Newer modes of echo like tissue doppler will improve the phase analysis of tissue motion and may provide us accurate information about preexcitation
The future looks bright . Time is not far off . . . where , we shall use ultrasound as an adjunct EP study .
*Fetal Echo = to Fetal electro cardiogram