I had a question about increasing PCV in a young dog. Originally though this to be a possible reverse PDA given the RVH. But subsequent scanning showed pulmonic stenosis.
- 4 yo MN JRT mix
- Acute dyspnea
- Episode of collapse
LV M-mode with thickened RV & small LV
So why is the dog’s PCV continuing to rise (from 64 to 68%)? This usually happens with reverse PDA’s so I’m confused!
I had a question about increasing PCV in a young dog. Originally though this to be a possible reverse PDA given the RVH. But subsequent scanning showed pulmonic stenosis.
- 4 yo MN JRT mix
- Acute dyspnea
- Episode of collapse
LV M-mode with thickened RV & small LV
So why is the dog’s PCV continuing to rise (from 64 to 68%)? This usually happens with reverse PDA’s so I’m confused!
I had a question about increasing PCV in a young dog. Originally though this to be a possible reverse PDA given the RVH. But subsequent scanning showed pulmonic stenosis.
Comments
Response from Peter Modler
Response from Peter Modler. As you already mentioned, the increase in PCV can be explained by R-L shunting. This happens, as soon the RV pressure exceeds the LV pressure. In PDA cases this is a consequence of pulmonary hypertension. In VSD cases either pulmonary hypertension or severe pulmonic stenosis can lead to an increase in RV pressures. The latter is of course better for the patient. Because if you reduce RV pressures by ballooning the pulmonic valve you can change the shunt direction from R-L to L-R. But is is of critical importance not to dilate the pulmonic valve too much because this would lead to pulmonary hyperperfusion and mid term to pulmonary hypertension – which is irreversible. The success of the ballooning procedure can be demonstrated by a decrease in the PCV, usually to a normal value. There are cases of pulmonic stenosis and concomitant pulmonary hypertension due to primary lung or vascular disease – they are very complicated. If you have a pulmonic stenosis with a pressure gradient below 80 mm Hg and a R-L shunt you have to consider pulmonary hypertension as a concomitant disease. In these cases the true pulmonary arterial pressure can only be estimated by either Doppler measurements of pulmonary insufficiency jets or by heart catheter. I had a case of a VSD and R-L shunt due to Pulmonic stenosis some months ago. I managed to reduce the pressure gradient across the PV to 50 mm Hg (was a Type B stenosis – means anular hypoplasia
) and the PCV decreased from 75% to 42%. The Patient was 3.5 yrs old and is doing fine now. Hope this helps! best Regards from rainy and very, very stormy Austria! Peter
Response from Peter Modler
Response from Peter Modler. As you already mentioned, the increase in PCV can be explained by R-L shunting. This happens, as soon the RV pressure exceeds the LV pressure. In PDA cases this is a consequence of pulmonary hypertension. In VSD cases either pulmonary hypertension or severe pulmonic stenosis can lead to an increase in RV pressures. The latter is of course better for the patient. Because if you reduce RV pressures by ballooning the pulmonic valve you can change the shunt direction from R-L to L-R. But is is of critical importance not to dilate the pulmonic valve too much because this would lead to pulmonary hyperperfusion and mid term to pulmonary hypertension – which is irreversible. The success of the ballooning procedure can be demonstrated by a decrease in the PCV, usually to a normal value. There are cases of pulmonic stenosis and concomitant pulmonary hypertension due to primary lung or vascular disease – they are very complicated. If you have a pulmonic stenosis with a pressure gradient below 80 mm Hg and a R-L shunt you have to consider pulmonary hypertension as a concomitant disease. In these cases the true pulmonary arterial pressure can only be estimated by either Doppler measurements of pulmonary insufficiency jets or by heart catheter. I had a case of a VSD and R-L shunt due to Pulmonic stenosis some months ago. I managed to reduce the pressure gradient across the PV to 50 mm Hg (was a Type B stenosis – means anular hypoplasia
) and the PCV decreased from 75% to 42%. The Patient was 3.5 yrs old and is doing fine now. Hope this helps! best Regards from rainy and very, very stormy Austria! Peter
Hi Peter & thanks for your
Hi Peter & thanks for your response! I neglected to mention the dog’s Doppler pressures:
RVOT = 6 m/s which = a gradient of 144 mmHg; Tricuspid regurg of 7.13 with a gradient of over 200 mmHG. On x-ray the lung fields were normal & pulmonary vasculature attenuated with an enlarged right ventricle. No PDA was seen at all. Systemic BP was 118 systolic.
I don’t think the dog will go to ballooning (financial issue).
Any other info would be great! Should rDVM keep drawing blood regularly to try to decrease PCV?
Best regards from a similar rainy & stormy Oregon!
Tomie
Hi Peter & thanks for your
Hi Peter & thanks for your response! I neglected to mention the dog’s Doppler pressures:
RVOT = 6 m/s which = a gradient of 144 mmHg; Tricuspid regurg of 7.13 with a gradient of over 200 mmHG. On x-ray the lung fields were normal & pulmonary vasculature attenuated with an enlarged right ventricle. No PDA was seen at all. Systemic BP was 118 systolic.
I don’t think the dog will go to ballooning (financial issue).
Any other info would be great! Should rDVM keep drawing blood regularly to try to decrease PCV?
Best regards from a similar rainy & stormy Oregon!
Tomie
I think the symptoms in your
I think the symptoms in your case are not caused by polycytemia but rather by R-L shunt and pulmonic stenosis. But if the PCV exceeds 70% I would perform a phlebotomy and withdraw 5ml/kg, not more because the increase of Erythrocytes is partly needed for providing sufficient oxygen. This can be repeated based on the PCV. It is also possible to administer hydroxyurea (as for polycytemia vera).
How much is ballooning in the States? It´s 1500 Euro in Austria… So if it´s much more expensive at your place then send it to us
Best Regards!
Peter
I think the symptoms in your
I think the symptoms in your case are not caused by polycytemia but rather by R-L shunt and pulmonic stenosis. But if the PCV exceeds 70% I would perform a phlebotomy and withdraw 5ml/kg, not more because the increase of Erythrocytes is partly needed for providing sufficient oxygen. This can be repeated based on the PCV. It is also possible to administer hydroxyurea (as for polycytemia vera).
How much is ballooning in the States? It´s 1500 Euro in Austria… So if it´s much more expensive at your place then send it to us
Best Regards!
Peter