Case Studies In Small Animal

Cardiovascular Medicine

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Third Visit

Case 34

Presenting Complaints

bulletPacemaker Implantation

Pertinent History

bulletChristopher presents today to the Soft Tissue Surgery Service for a pacemaker implantation. He first presented two weeks ago to the Neurology Service with a complaint of collapsing episodes. Previous echocardiogram indicated changes consistent with an idiopathic hypertrophy of the subaortic septum, mild mitral valve degeneration, and mild aortic regurgitation. Christopher also had mild left atrial enlargement. His ECG at that time revealed an intermittent third degree AV block. He was prescribed aminophylline at 25 mg BID PO. After a neurological workup on the 21st determined that his episodes were more than likely episodes of syncope and not seizures, Christopher received a workup from the Cardiology Service. An event monitor was placed and Christopher was released from the hospital on 5/22. Upon review of the recording, a pause of 12 seconds and several other long pauses of complete heart block were found. It was determined at that time that Christopher should have a pacemaker implanted and an appointment was made.
bulletThe owners put Christopher back on aminophylline on one week ago after the event monitor had been removed (the aminophylline had been temporarily discontinued during his workup here at the VMTH). Since putting him back on the aminophylline they report that his activity level and appetite have been great and they have not noticed any C/S/V/D. There were no episodes of syncope until 2 days ago and yesterday (6/3). On those days he had two separate syncopal episodes each day. The episodes began with shaking, wobbling, and then falling over. They only lasted about 5-10 seconds and the owners feel that they were much less severe than previous episodes. The owners are hesitant today about going ahead with the pacemaker implantation and would like a consult from the surgeon and their options.

Physical Examination

bulletGEN: BARH, T 100.4
bulletINTEG: full hair coat with some debris; ventral thorax and right jugular area are shaved.
bulletEENT: Ears: moderate cerumen AU. Eyes: slight crusty discharge OU, clear sclera/anterior chambers. Nose: clean with no discharge. Throat: moderate calculus on all molars.
bulletMS: BCS 5/9, no lameness or atrophy noted, ambulatory X 4.
bulletCV: HR 84, femoral pulses are weak, 2-3/6 systolic murmur, CRT 1.5 sec., mm=pink.
bulletRESP: RR 30, normal breath sounds in all lung fields
bulletGI/GU: no organomegaly, smooth bowel loops palpated.
bulletNS: proper mentation, no further examination completed.
bulletLN: all peripheral nodes < 1 cm


bullet2/6 Systolic Heart Murmur
bulletThird Degree AV Block

Discharge Summary

bulletChristopher presented to the Soft Tissue Surgery Service on 6/4/02 for a pacemaker implant. He was diagnosed with bradycardia and a 2-3/6 systolic murmur with a third degree AV block on 5/21/02.
bulletAn event monitor was placed on 5/22/02 and indicated several long pauses of complete heart block with one episode lasting 9 seconds.
bulletThe owners placed Christopher back on 25 mg of aminophylline BID PO after his diagnostic workup here and he has not had any syncopal episodes from 5/27/02 until Sunday 6/2/02. On Sunday and Monday he had two separate syncopal episodes lasting about 5 seconds each.
bulletAfter consultation with a surgical clinician today, the owners have elected to take Christopher home and continue to treat him medically until at which time they feel his quality of life has diminished and he can no longer be managed medically.
bulletSince the anesthetic risk would be great if Christopher should go into surgery for the implant, the owners feel they would like to wait at this time until they have no other options. At that time they will return for the pacemaker to be implanted.
bulletThey were asked to continue on the aminophylline and make an appointment with the Cardiology Service in 30 days for another recheck.

Mark D. Kittleson, D.V.M., Ph.D. All rights reserved.