Case 40 — Procedure & Follow-up

5/27/10

  • S: Chanel, a 3yo FS Maltese, was presented to the UC Davis Cardiology service on 5/26/10 for evaluation and treatment of Cor Triatriatum Dexter. II/VI R basilar continuous murmur was auscultated.
  • O: T 100.8, P 170, R pant. PCV 59, TP 5.4, fluid wave on abdominal palpation. Strong synchronous, symmetric pulses. Abdominocentesis produced 650 mL of fluid. Thoracic radiographs revealed a markedly dilated CVC, enlarged RA, hepatomegaly, and decreased serosal detail diffusely in the abdomen. ECG revealed sinus tachycardia at 230 bpm and tall P waves at 0.5–0.8 mV. The remainder of the ECG was WNL. Echo revealed a right atrium with two compartments separated by a membrane. A defect in this membrane allows for blood flow with an increased velocity of 2.44 m/s. The caudal vena cava leads into the dilated caudal chamber. The cranial vena cava and AV valve communicate with the cranial right atrium.
  • A: Cor Triatriatum Dexter leading to R-sided congestive heart failure, manifested in dilated CVC, hepatomegaly, and ascites.
  • P: GA and balloon dilation of the membrane in the right atrium tomorrow.

5/27/10 — Procedure

  • S/O: During echo, diluted H2O2 was introduced into the femoral vein. Microbubbles rapidly filled the caudal RA, and then slowly filled the cranial RA. The patient was anesthetized. A trans-esophageal echo (TEE) prior to the procedure was performed, and a defect was located in the membrane in the R atrium. The defect was 0.26 cm in diameter. Cardiac catheterization revealed an initial PG of 25 mmHg (cranRA of 5 mmHg, caudRA of 30 mmHg). An angiogram was done (see below). Balloon dilation of the defect was performed. Following the procedure, cardiac catheterization was repeated and the pressure gradient was reduced to 2 mmHg (cranRA of 8 mmHg, caudRA of 10 mmHg). The procedure was without complication. Supraventricular tachycardia was noted during atrial manipulation with the catheter.

Angiogram — contrast agent was injected into the caudal vena cava

Contrast can be seen entering the large caudal right atrial chamber and then slowly filling the cranial chamber and right heart as contrast flows through the defect.

Technical Notes

Catheters used during the balloon dilation procedure: A 7F introducing sheath was placed in the right femoral vein. A 5F x 60 cm x 0.025” balloon wedge pressure catheter was used to perform various pressure recordings and angiograms. Balloon dilation was performed using 2 balloon catheters in succession: #1—NuMed Tyshak II 10 mm x 2 cm x 5F x 60 cm x 0.025”, #2—Cook 14 mm x 2 cm x 60 cm x 6F x 0.035”. Catheter exchanges were facilitated with a 0.025” x 150 cm J-tipped guide wire.

Post-procedure

  • T 100, P 110, R pant. Fluid wave palpated; murmur no longer audible; mild inflammation and SC emphysema around the incision site on the right rear limb. The incision site did not seem painful on gentle palpation. Patient urinated and defecated normally. Hydromorphone 0.18 mg SC was not administered until 2000h.
  • A: The RA membrane was adequately disrupted to allow the PG to decrease. The decreased pressure in the caudal RA should lead to the resolution of the ascites and hepatomegaly. Post-surgical echocardiogram indicates improved blood flow (reduced velocity) through the membrane.
  • P: Repeat echocardiography tomorrow. Feed, water, walk TPR, assess pain. D/C furosemide.

5/28/10 — Discharge

  • S/O: T 100.3, P 128, R 48. Incision site mildly inflamed, incision site non-painful to gentle palpation. Patient walks normally after an initial weight-bearing lameness. Good appetite. Mild abdominal fluid (unchanged). No murmur auscultated. Echo revealed an increased size of the right atrial membrane defect and decreased velocity across the defect. Decreased size of caudal RA.
  • A: Successful balloon valvuloplasty of the CTD.
  • P: Discharge this afternoon.
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