In vascular ultrasound we are describing mono-, bi- ant triphasic waveforms in arteries.

In normal arteries we have the triphasic wave: rapid systolic anterograd flux, short retrograde flux in early diastole and slow anterograde flux in late diastole. In stenosis the wave becomes biphasic, loosing its diastolic components: it is systolic anterograde flow and then doppler-silence in diastole. In severe stenosis, the wave becomes monophasic: rapid anterograde flow in systole and slow anterograde flow in diastole, ususally with low velocities, turbulence, rounded peaks:

It means the trend of the ECG signal deflection. If the deflection or change of the sign changes twice (go up to positive, then down to negative and then back to zero) it is biphasic. If there are three deflections (three peaks, i.e two positive and one negative), it is called triphasic.

Check the attached figure to understand it (the photo taken from the following book: http://books.google.com.om/books?id=krbOcMuLDSAC&lpg=PA99&ots=--tSWObdtl&dq=biphasic%20vs%20triphasic%20ecg&pg=PA114#v=onepage&q=biphasic%20vs%20triphasic%20ecg&f=false).

Regards,

Asiya

In vascular ultrasound we are describing mono-, bi- ant triphasic waveforms in arteries.

In normal arteries we have the triphasic wave: rapid systolic anterograd flux, short retrograde flux in early diastole and slow anterograde flux in late diastole. In stenosis the wave becomes biphasic, loosing its diastolic components: it is systolic anterograde flow and then doppler-silence in diastole. In severe stenosis, the wave becomes monophasic: rapid anterograde flow in systole and slow anterograde flow in diastole, ususally with low velocities, turbulence, rounded peaks:

Biphasic Waveforms is a type of defibrillation waveform where a shock is delivered to the heart via two vectors. Biphasic waveforms improve defibrillation efficacy by two possible separate mechanisms 1) Reduction of the defibrillation threshold and 2)Amelioration of shock-induced dysfunction.

Where as Triphasic defibrillation waveforms cause less myocardial injury than biphasic waveforms. Previous studies reported that Triphasic waveforms defibrillate with a lower DFT than monophasic waveforms but with an equal or higher DFT than biphasic waveforms. Triphasic waveforms are superior to biphasic waveforms for transthoracic defibrillation. Experimental studies confirm that Triphasic shocks of equal duration pulses achieved higher success than biphasic shocks at delivered low energies. Triphasic transthoracic shocks composed of equal duration pulses are superior to biphasic shocks for ventricular fibrillation termination at low energies and caused less VT and asystole.

Dear Ananyaja Debadipta,

Biphasic and triphasic is a very common way to describe the number of turns of a wave, either twice or triple sign changes respectively.

nice explanations-- one loop on base line is monophasic-two loops biphasic and triphasic are three loops.

biphasic is in respect to zero