Upload
others
View
0
Download
0
Embed Size (px)
Citation preview
Practical CardiologyCase StudiesPractical CardiologyCase Studies
Wendy Blount, DVM
Nacogdoches TX
Wendy Blount, DVM
Nacogdoches TX
GingerGinger
Signalment
• 12 year old SF cocker spaniel
Chief complaint
• Several episodes of collapse during the past month
• Description matches partial seizure
• Rear legs get weak on walks
• Lethargic and dull in general
GingerGinger
Exam
• Dark maroon oral mucous membranes
• Rear foot pads cyanotic (heart sounds)
• Split S2
• Neurologic exam normal, except dull mental
status
GingerGinger
Differential Diagnosis – Split S2
• Pulmonic and aortic valves don’t close at the same time
– Pulmonary hypertension
– Normal variation in giant dogs
– Reverse PDA
Differential Diagnosis - cyanosis
• Respiratory hypoxia
• Cardiac hypoxia
GingerGinger
Initial Diagnostic Plan
• CBC, GHP, electrolytes
• Arterial blood gases, Pulse oximetry
• ECG
• Thoracic radiographs
Bloodwork
• Tech couldn’t get enough serum for serology
• CBC – PCV 73%
• GHP and electrolytes - normal
GingerGinger
DDx Differential Cyanosis
• FATE – Femoral Artery ThromboEmbolism
– Lack of femoral pulses
– Feet cool to the touch
• Right to Left shunt – ductus is distal to the brachiocephalic trunk
– Reverse PDA
– AV fistula with pulmonary hypertension
– Tetralogy of Fallot
GingerGinger
Arterial blood gases
• pO2 – 52 mmHg
• pCO2 – 36 mmHg
• all else normal
Pulse oximetry
• Lip – O2 sat 89%
• Vulva - O2 sat 67%
GingerGinger
GingerGinger GingerGinger
Thoracic radiographs
• Normal great vessels
• Normal heart size (VHS 9.5)
• aortic bulge on VD, PA bulge on VD
• No evidence of severe respiratory disease
which might cause hypoxia
• No evidence of heart failure
GingerGinger
ECG
• S wave mildly deep in leads I,, II, III, aVF
• MEA 90o
• Arrhythmia doesn’t seem likely
Differential Diagnoses
• Right to left shunt
• Pulmonary hypertension
GingerGinger
GingerGinger
ECG
• S wave mildly deep in leads II, III, aVF
• MEA 90o
• Arrhythmia doesn’t seem likely
Differential Diagnoses
• Right to left shunt
• Pulmonary hypertension
GingerGinger
Right to Left Shunt
• Reverse PDA (right to left)
– Eisenmeinger’s physiology
• Tetralogy of Fallot
• AV fistula with pulmonary hypertension
Echocardiogram
GingerGinger
Right to Left Shunt
• Reverse PDA (right to left)
– Eisenmeinger’s physiology
• Tetralogy of Fallot
• AV fistula with pulmonary hypertension
Echocardiogram
GingerGinger
Right to Left Shunt
• Reverse PDA (right to left)
– Eisenmeinger’s physiology
• Tetralogy of Fallot
• AV fistula with pulmonary hypertension
Echocardiogram
GingerGinger
Right to Left Shunt
• Reverse PDA (right to left)
• Tetralogy of Fallot
• AV fistula with pulmonary hypertension
Echocardiogram
• RV thickening, flattening of the IVS
• RV normally thinner than LV
• No PDA seen without Doppler
GingerGinger
Bubble Study
• Place venous catheter
• Shake 5-10 cc saline vigorously
• Place US probe where you can look for shunting
– Long 4 chamber view
– Abdominal aorta
• Inject IV quickly
• Bubbles normally appear on the right (video)
• Watch for bubbles on the left (this means R to L shunt)
• False negatives when bubbles disperse quickly
Reverse PDAReverse PDA
• Reverse PDAs are usually large, providing no resistance to blood flow
– Ductus is often as large in diameter as the great vessels it
connects
• increase in pulmonary artery pressure combined with the increase in pulmonary blood flow creates pathologic responses in the pulmonary arteries over time
• a continuous murmur is heard during the first days to weeks of life but disappears before the eighth week
• Often do well until polycythemia develops late in life
Reverse PDAReverse PDA
Treatment
• Ligation of right to left shunting PDA results in death due to pulmonary hypertension
– Has been ligated in stages without causing death
– Cyanosis and symptoms usually persist
• Managed Medically by periodic phlebotomy
– Remove 10 ml/lb and replace with IV fluids
– Eliminate hyperviscosity without inducing hypoxia
– Goal for PCV is 60-65%
– Excellent blood for RBC transfusion ;-)
– Repeat when clinical signs return
Reverse PDAReverse PDA
Treatment
• Hydroxyurea
– 30 mg/kg/day for 7 to 10 days followed by 15 mg/kg/day.
– CBC q1-2 weeks
– D/C when Bone marrow suppression
– Resume lower dose
– Some dogs require higher doses
– side effects – GI and sloughing of the nails
Reverse PDAReverse PDA
Prognosis
• Can do well short term
• Poor prognosis long term
– Survival months to a year or two
• Phlebotomy interval is progressively shorter
HankHank
Signalment
• 10 week old male schnauzer
Chief Complaint
• Loud heart murmur heard on examination for routine vaccinations
• Suspect congenital heart defect
HankHank
Exam
• mm pink, CRT 2 sec
• 4/6 ejection murmur loudest at left heart base (audio)
• Mild superficial pyoderma
HankHank
Initial Differential Diagnoses
• Pulmonic stenosis
• Aortic Stenosis
Initial Diagnostic Plan
• Chest x-rays
• EKG
• Echocardiogram
HankHank
HankHank HankHank
Thoracic radiographs
• Dorsally elevated trachea
• Vertebral heart score 9.5
• Right heart enlargement
• Right auricular/atrial enlargement
• Distended caudal vena cava
• Bulge at main pulmonary artery
HankHank
EKG
• Tall P waves (0.5-0.6 mV)
• RA enlargement
• Deep S waves in leads I, II and III (-13 to -15 mV)
• RV enlargement
• Tachycardia 200-210 bpm
• Under Buprenex-ace sedation
Hank - EchoHank - Echo
Hank - EchoHank - Echo
Short Axis – LV Apex
• RV seems thickened
Short Axis – LV PM, MV, Ao/RVOT
• RV as thick as LV – markedly thickened
• IVS is flattened
Hank - EchoHank - Echo
Hank - EchoHank - Echo
Short Axis – PA
• MPA dilated
• RV as thick as LV – markedly thickened
Long Axis – 4 Chamber
• Aberrant septum dividing RA into 2 chambers – cranial and caudal
Long Axis – LVOT
• RV as thick as LV – markedly thickened
Hank - EchoHank - Echo
Hank - EchoHank - Echo
Diagnosis
• Likely Pulmonic Stenosis
• DDx RV thickening
– Heartworms impossible in a 10 week old puppy
– Pulmonary hypertension rare in a 10 week old puppy
• Need Doppler to confirm, and to determine gradient
• Cor triatriatum dexter
Hank - EchoHank - Echo
Plan – updated
• Referral to TAMU for balloon valvuloplasty
• Atenolol 0.5 mg/kg PO BID (monitor weight to increased dose PRN until cath procedure)
Pulmonic StenosisPulmonic Stenosis
Clinical features
• Many breed predispositions
– Bulldog, chihuahua, Beagle, Cavalier
• Often valvular and subvalvular
• Valvular defect can be corrected by valvuloplasty
• Prognosis varies, depending on severity
– Mild – less than 50 mm Hg gradient
– Moderate – 50-100 mm Hg
– Severe - >100 mm Hg
• Can be progressive
Pulmonic StenosisPulmonic Stenosis
Clinical features
• Bulldogs and Boxers can have left coronary artery anomaly, which can preclude balloon valvuloplasty
• Arrhythmia is much more common than RHF
• May be part of Tetralogy of Fallot
– PS
– RV hypertrophy
– VSD
– Overriding aorta
Pulmonic StenosisPulmonic Stenosis
Coronary Artery Anomaly
• Instead of R and L coronary aa, there is a single
coronary a.
• It splits and the left branch encircles the pulmonary a.
• It can be ruptured if the PS
is ballooned
• These dogs may have
normal PV and functional
PS due to this anomaly
Pulmonic StenosisPulmonic Stenosis
Echocardiographic abnormalities
• RV thickening
• Post-stenotic dilatation of MPA
• Pulmonic valve may be thickened with poor movement
• Paradoxical septal motion may be noted in severe cases
• Tricuspid dysplasia is a common concurrent malformation
– RHF is rare in dogs with PS alone
– Many PS dogs that develop RHF also have tricuspid dysplasia
(Client Handout)
SuzieSuzie
Signalment
• 2 year old female chihuahua mix
Chief Complaint
• Loud heart murmur heard on free examination for shelter pup
Exam
• Left apex (audio)
– holosystolic murmur PMI left apex (MR murmur) due to left volume overload
• Left axilla (audio)
– Continuous machinery murmur at the left base (left armpit)
• Hyperkinetic pulses
• Left apical heave on precordial palpation
SuzieSuzie
Thoracic Rads
• MPA dilation
• Aortic dilation
• Generalized cardiomegaly
SuzieSuzie
Thoracic Rads
• LV dilation
– Elevated trachea
– Inc VHS
• LA dilation ?
• Left CHF
– Perihilar edema
– Enlarged pulmonary
Lobar veins
SuzieSuzie
Treatment
• Furosemide 12.5 mg PO BID
• Enalapril 2.5 mg PO BID
• Pimobendan 1.25 mg PO BID
2 week recheck
• CHF controlled – resolution of edema
SuzieSuzie
Echocardiogram
• IVSd 8.0 (n. 6.2-7.8)
• LVIDd 35.1 (n. 21.3-25.8)
• LVWd 7 (n. 5.0-6.3)
• IVSs 11.0 (n. 9.4-11.2)
• LVIDs 15.1 (n. 11.9-15.2)
• IVDs 9.3 (n. 8.3-10.0)
• LAd 18 (n. 13.4-16.1)
• AoS 14.1 (n. 13.5-15.5)
• LA:Ao – 1.3 (n. 0.8-1.3)
• FS = 57%
• MPA jet dilation
• Can see PDA at transverse MPA view
Eccentric hypertrophy
LV overload, CHF controlled
No Myocardial failure
Dx - PDA
SuzieSuzie
SuzieSuzie Patent Ductus ArteriosusPatent Ductus Arteriosus
Echocardiographic Features
• Can see PDA at transverse MPA view
• Doppler can find PDAs that aren’t easily visualized
• FS hyperdynamic unless myocardial failure
Treatment
• Surgical ligation
SuzieSuzie
2 week recheck
• CHF controlled – weaned off meds
• Still doing well 60 days later
• But…. Murmur returned – left axillary area (audio)
• No mitral murmur
Treatment
• Cath procedure for coil placement
SuzieSuzie
2 week Post-Op Rads
SuzieSuzie
2 week Post-Op Rads
SuzieSuzie
Asymptomatic for 8 yrs
Then began coughing
SuzieSuzie
Asymptomatic for 8 yrs
Then began coughing
• FNA Cytology
• Adenocarcinoma
• Euthanized 6 months
later
SuzieSuzie
Sub-Aortic StenosisSub-Aortic Stenosis
Clinical Features
• Large breeds more common than small
• Valvular and supravalvular stenosis very rare
• Does not lend itself to balloon valvuloplasty
• Patch grafts are being tried at TAMU
• Anatomic expression may not occur until several weeks to months old
• Disease can be progressive or regressive
Sub-Aortic StenosisSub-Aortic Stenosis
Clinical Features
• Doppler is required to determine severity
• Prognosis depends on severity
– Mild – 0-50 mm Hg
– Moderate – 50-100 mm Hg
– Severe - >100 mm Hg
Sub-Aortic StenosisSub-Aortic Stenosis
Echocardiographic Features
• IVS and LVPW thickening
• An echodense ridge or band may be seen on the long LVOT view, especially if severe
• Aortic valve may be abnormal
– Thickened (rare)
– Decreased movement (rare)
– Delay in opening of AV after systole
– Excessive systolic fluttering
Sub-Aortic StenosisSub-Aortic Stenosis
Echocardiographic Features
• Doppler can identify those SAS which can not be visualized directly
• FS usually normal to slightly increased
Sub-Aortic StenosisSub-Aortic Stenosis
Treatment
• Treat arrhythmia if present
– Atenolol 0.5 mg/kg PO BID
• Treat left heart failure if present
• Treat aortic regurgitation if present
– Hydralazine 0.5 mg/kg PO BID
– Titrate up to 2 mg/kg PO BID to reduce systolic BP
by 10-20 mm Hg
Sub-Aortic StenosisSub-Aortic Stenosis
Treatment
• Treat arrhythmia if present
– Atenolol 0.5 mg/kg PO BID
• Treat left heart failure if present
• Treat aortic regurgitation if present
– Hydralazine 0.5 mg/kg PO BID
– Titrate up to 2 mg/kg PO BID to reduce systolic BP
by 10-20 mm Hg
Sub-Aortic StenosisSub-Aortic Stenosis
Treatment
• Treat arrhythmia if present
– Atenolol 0.5 mg/kg PO BID
• Treat left heart failure if present
• Treat aortic regurgitation if present
– Hydralazine 0.5 mg/kg PO BID
– Titrate up to 2 mg/kg PO BID to reduce systolic BP
by 10-20 mm Hg
Sub-Aortic StenosisSub-Aortic Stenosis
Treatment
• Treat arrhythmia if present
– Atenolol 0.5 mg/kg PO BID
• Treat left heart failure if present
• Treat aortic regurgitation if present
– Hydralazine 0.5 mg/kg PO BID
– Titrate up to 2 mg/kg PO BID to reduce systolic BP
by 10-20 mm Hg
Sub-Aortic StenosisSub-Aortic Stenosis
Treatment
• Treat arrhythmia if present
– Atenolol 0.5 mg/kg PO BID
• Treat left heart failure if present
• Treat aortic regurgitation if present
– Hydralazine 0.5 mg/kg PO BID
– Titrate up to 2 mg/kg PO BID to reduce systolic BP
by 10-20 mm Hg
ASD and VSDASD and VSD
Clinical Features
• Disease is a result of left to right shunting
• This causes pulmonary hypertension and right heart failure
– caudal caval distension, hepatic vein distension
– jugular vein distension/pulses/reflux
– Ascites
– Pericardial effusion
– Pleural effusion
ASD and VSDASD and VSD
Echocardiographic Features - VSD
• In dogs and cats, most VSDs occur in membranous IVS, at the top of the LV near the atria
• Need to be 1 cm to reliably seen on echo
• Doppler can find those that can not be seen directly
• May see abnormal septal motion due to conduction interruption
• Occasionally can see right cusp of AV prolapsing,
creating aortic regurgitation
• Huge RA and MPA; RV dilation
ASD and VSDASD and VSD
Echocardiographic Features - ASD
• ASD much less likely to cause clinical signs than VSD
• Do not confuse with drop-out of fossa ovalis
• Doppler can confirm
• If large enough, may see right volume overload
– Enlarged RA and RV
– Enlarged MPA
SummarySummary
• PowerPoint – Cases – Congenital Heart Defects
• .pdf of PowerPoint – Cases - Congenital Heart Defects
• Client Handouts– PDA
– Subaortic Stenosis
– Pulmonic Stenosis
– VSD