Renal bruit – bruit due to renal artery stenosis
Epigastric bruit conducted laterally is suggestive of renal bruit. But many of the renal bruit occur due to ostial stenosis of the renal artery, which may not be conducted laterally. Bruit due to renal artery stenosis may also be heard in the renal angle, posteriorly.
Orientation of echo beam vs Doppler interrogation
For 2D imaging the ultrasound beam has to be perpendicular to the structure being imaged to get good images while in Doppler interrogation, the beam has to be parallel to the flow to get good velocity spectrum. If the angle between the beam and the direction of flow is more than 20 degrees, the error in estimated velocity will be high.
How are the angiographic measurements calibrated?
Angiographic measurements are calibrated with reference to the catheter used. 6F catheter will have a diameter of 2 mm (1F ~ 0.33 mm).
What precaution will you take while taking aortic root angio to assess aortic regurgitation?
The catheter tip should be outside the sinus of Valsalva to prevent the catheter from physically interfering with the closure of the aortic leaflets and producing artefactual aortic regurgitation.
Contraindications for insertion of intra aortic balloon for counter pulsation (IABP)
Aortic regurgitation and aortic disease are contraindications, both are likely to be worsened by the balloon counterpulsation. In aortic regurgitation, the main aim of improving coronary perfusion with IABP will not be achieved. It is interesting to note that diastolic pressure will be more than systolic pressure when IABP is used for cardiogenic shock. The balloon inflation is timed either by the pressure wave or by the ECG to correspond to the diastolic period. The balloon is positioned below the left subclavian origin and above the level of the renal arteries, in the descending aorta.
Crawford Coselli classification of Thoraco-abdominal Aortic Aneurysm
Type I: Only supra renal portion of aorta is involved
Type II: Entire thoraco-abdominal descending aorta is involved, upto the bifurcation
Type III: Distal half of descending thoracic aorta and abdominal aorta upto the bifurcation is involved.
Type IV: Entire infra-diaphragmatic (abdominal) portion of descending aorta is involved