Basic Echocardiography Additional Information Wendy Blount, DVM Nacogdoches TX Wendy Blount, DVM Nacogdoches TX.

Basic EchocardiographyAdditional Information

Basic EchocardiographyAdditional Information

Wendy Blount, DVMNacogdoches TXWendy Blount, DVMNacogdoches TX

Heartworm DiseaseHeartworm Disease

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Cardiac MassesCardiac Masses

DDx• Chemodectoma• HSA• Myxosarcoma• Ectopic thyroid carcinoma• Mesothelioma• LSA• fibrosarcoma

Cardiac MassesCardiac Masses

Echocardiographic Features• Usually at the heart base or in the RA• Careful not to confuse with

– Epicardial fat (especially on the AV groove when there is pericardial effusion)

– Trabeculae on the right auricle when floating in pericardial effusion

Patent Ductus ArteriosusPatent Ductus Arteriosus

Clinical Features• Unique murmur

– May hear holosystolic murmur PMI left apex (MR murmur) due to left volume overload

– Continuous machinery mumur is sometimes heard only at the left base (left armpit)

• Hyperkinetic pulses• Often left apical heave on precordial palpation• Left CHF may be present if severe

Patent Ductus ArteriosusPatent Ductus Arteriosus

Echocardiographic Features• LV dilation• LA dilation• MPA jet dilation• Aortic dilation• Can see PDA at transverse MPA view• Doppler can find PDAs that aren’t easily visualized• FS hyperdynamic unless myocardial failure

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

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

Boxer CardiomyopathyBoxer Cardiomyopathy

• Can be primarily ventricular arrhythmia• Can be primarily DCM• Can have both• If arrhythmia is primary, treatment of choice:

– Sotalol 1-3 mg/kg PO BID– Beta blocker and class III antiarrhythmic

Right to Left shuntingRight to Left shunting

DDx• Reverse PDA

– Eisenmeinger’s physiology

• Tetralogy of Fallot• AV fistula with pulmonary hypertension

Diagnosis• Bubble study• Pulse oximetry for reverse PDA

Right to Left shuntingRight to Left shunting

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• Watch for bubbles on the right• False negatives when bubbles disperse quickly

Right to Left shuntingRight to Left shunting

Reverse PDA• Often do not have a murmur• Often present for cyanosis or seizures/neuro• Rads similar to PDA• Treatment

– Periodic phlebotomy (10 ml/lb + IV fluid therapy)

• Prognosis– Can do well in the short term– Depending on how long phlebotomy gives relief– Poor prognosis long term