Presentation

A 2.5 year old male Pomeranian was presented for evaluation of exercise intolerance. The patient was previously diagnosed with severe valvular pulmonic stenosis ~ 2 years prior. Currently patient was experience episode of exercise intolerance and occasional episode of collapse (suspected syncope)

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Echocardiogram

There is fusion of the pulmonic valve leaflets noted with little to no decrease in annular diameter. The aortic to pulmonic annular ration was 1.05 which is consistent with Type A pulmonic stenosis. The Doppler derived pressure gradient was ~ 120 mm Hg. Marked eccentric and concentric hypertrophy of the right ventricle was noted consistent with pressure overload.

Figure 1: (A) Right parasternal short axis echocardiographic image at the level of the pulmonic valve showing the typical appearance of a type A pulmonic stenosis. Note the pulmonic annular diameter is similar to the aortic annular diameter as well as the fused leaflets that protrude into the main pulmonary artery as a conical windsock structure. (B) Left cranial parasternal short axis view at the level of the aortic valve showing the typical appearance of type B pulmonic stenosis. Note the marked narrowing of the pulmonic annulus when compared to the aortic annulus as well as the thick leaflets.

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Treatment Plan

Balloon valvuloplasty was recommended due to the onset of clinical signs. A good outcome was expected due to the stenosis being type A.

Figure 2: Side view of balloon catheter used for valvuloplasty showing progressive inflation moving from left to right.

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Outcome

Patient was placed under general anesthesia and an 18 mm by 4 cm balloon catheter was positioned across the pulmonic valve in inflated 2 separate times. Access was provided via cut down of right external jugular using a modified Seldinger single wall technique.

Figure 3: Right lateral fluoroscopic view showing balloon valvuloplasty of the pulmonic valve. Note the hourglass shape of the balloon (arrow) due to the narrowing (stenosis) at the pulmonic valve.

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Follow-Up

Re-evaluation at 1 year indicated the pressure gradient across the pulmonic valve remains elevated but stable at ~ 50 mm of Hg which is a 60% reduction. Additionally, there was improvement in right ventricular chamber shape and wall thickness as well as right atrial chamber size. Following the procedure, the exercise intolerance and episodes of collapse resolve. Clinically the patient was doing well at home with no signs of symptoms of cardiac disease.