Ventricular Septal Defect in a 1.5-year-old FS Boxer: Our Case Of the Month October 2017
Innocent murmur… I think not! Here is a case where acting on a heart murmur, no matter the age or grade, is a prudent choice in clinical practice. A young, rambunctious boxer was presented for an echocardiogram and ECG, for a low grade (1/6) heart murmur that had continued to be auscultated after several puppy visits to her veterinarian. No obvious clinical signs were present, other than panting, but not unusual for an exuberant puppy in a clinic setting! Many thanks to Dr. Shelly Knopsnyder of East Lane Veterinary Hospital and her awesome team in managing this case. SDEP-certified sonographer, Amanda Lacey of Animal Sounds NW provided the diagnostic images for this case study.
A 1.5-year-old, FS, Boxer was presented for an initial puppy wellness visit and a grade 1/6 cardiac murmur was detected; noted PMI (point of maximal impulse) right cranial. A grade 1-2/6 cardiac murmur was detected at several follow-up visits. The patient underwent ovariohysterectomy without event. More recently the patient was presented for further cardiac evaluations. PE found the patient with a heartrate of 140, panting but with no increased respiratory effort, and synchronous pulses. BP: 111/51, 95/53 MAP 67, 119/66 MAP 78. 2 ECG strips were submitted. The first strip (taken under sedation with butorphanol) showed periods of sinus rhythym and periods that appeared to be a high grade second degree AV block (ventricular rate 40-100 bpm). The second strip showed a sinus rhythm (rate 114 bpm) with intermittent single premature ventricular complexes (RBBB morphology) once sedation had worn off and patient was stimulated.
A sinus rhythm was observed during the echocardiogram. There is a dilated coronary sinus. Trivial mitral regurgitation is suspected. The tricuspid valve leaflets are thickened and the septal leaflet is thethered in some views, although there is no tricuspid regurgitation. There is an area of left to right flow (beneath the junction of the right and non-coronary aortic cusps high in the ventricular septum).