Practical Cardiology Case Studies Wendy Blount, DVM Nacogdoches TX Wendy Blount, DVM Nacogdoches TX

Jasper Signalment: Middle Aged Adult Norwegian Forest Cat Male Castrated 13 pounds Chief Complaint: Acute Dyspnea 1 day after sedation with ketamine and Rompun for grooming Cannot auscult heart or lung sounds well - muffled

Jasper Immediate Diagnostic Plan: Lasix 25 mg IM – then in oxygen cage When RR <50, lateral thoracic radiograph Differential Diagnosis – Pleural effusion Transudate - Hypoalbuminemia Modified Transudate – Neoplasia, CHF Exudate – Blood, Pyothorax, FIP Chylothorax(chart)chart

Jasper Initial Therapeutic Plan: Thoracocentesis Tapped both right and left thorax Removed 400 ml of pink opaque fluid that resembled pepto bismol Fluid had no “chunks” in it Differential Diagnosis – updated Pyothorax Chylothorax

Jasper Initial Diagnostic Plan: Fluid analysis –Total solids 5.1 –SG –Color- pink before spun, white after –Clarity – opaque –Nucelated cells 8500/ml –RBC 130,000/ml –HCT 0.7%

Jasper Initial Diagnostic Plan: Fluid analysis –Lymphocytes 5600/ml –Monocytes 600/ml –Granulocytes 2300/ml –No bacteria seen –Triglycerides 1596 mg/dl –Cholesterol 59 mg/dl Chylothorax

Jasper DDx Chylothorax Trauma – was chewed by a dog 2-3 mos ago Right Heart Failure Pericardial Disease Heartworm Disease Neoplasia –Lymphoma –Thymoma Idiopathic

Jasper Diagnostic Plan - Updated PE & Cardiovascular exam CBC, general health profile, electrolytes Occult heartworm test Post-tap chest x-rays Echocardiogram

Jasper Exam Temp 100, P 180, R 48, BCS 3, BP 115 3/6 systolic murmur Anterior mediastinum compressible Pleural rubs No jugular pulses, no hepatojugular reflux Peripheral pulses slightly weak Mucous membranes pink, CRT 3 sec

Jasper Bloodwork Occult Heartworm Test - negative CBC – normal GHP – –Glucose 134 (n ) –Cholesterol 193 & TG 137 (both normal) Chest X-rays Post-tap chest x-rays

Jasper Chest X-rays Minimal pleural effusion No cranial mediastinal masses Normal cardiac silhouette (VHS 7.5) Normal pulmonary vasculature Lungs remain scalloped

Jasper – Echo Short Axis – LV apex (video of similar cat)video No abnormalities noted Short Axis – LV PM No abnormalities noted IVSTD – 8.8 mm (n 3-6) LVIDD – 16.2 mm (normal) LVPWD – 7.2 mm (n 3-6) IVSTS – 9.8 mm (n 4-9) LVIDS – 10.5 mm (normal) LVPWS – 10.1 mm (n 4-10) FS – 35%

Jasper – Echo Short Axis – MV No abnormalities noted Short Axis – Ao/RVOT Smoke in the LA AoS – 11.7 mm ( normal) LAD – 10.5 (normal) LA/Ao – 0.9 (normal)

Jasper – Echo Short Axis – PA Difficult to evaluate due to “rib shadows” Long Axis – 4 Chamber Hyperechoic “thingy” in the LA, with smoke Long Axis – LVOT Aortic valve seems hyperechoic, but not nodular 2-3 cm thrombus free in the LA

Jasper – Echo Short Axis – Ao/RVOT - repeated LA 2-3x normal size, with Smoke AoS – 11.7 mm ( normal) LAD – 29 mm (n 7-17) LA/Ao – 2.5 (n )

Jasper – Echo Therapeutic Plan - Updated Furosemide 12.5 mg PO BID Enalapril 2.5 mg PO BID Rutin 250 mg PO BID Low fat diet Plavix mg PO SID Lovenox 1 mg/kg BID Fragmin 1 mg/kg BID Clot busters only send the clot sailing

Jasper – Echo Recheck – 1 week Jasper doing exceptionally well –back to normal. Lateral chest radiograph Jasper declined all other diagnostics, without deep sedation/anesthesia Will do BUN, Electrolytes, BP, recheck echo to assess thrombus in one month

Jasper – Echo Recheck – 1 month Jasper doing exceptionally well Lateral chest radiograph – no change Jasper declined all other diagnostics, without deep sedation/anesthesia Will do BUN, Electrolytes, BP, recheck echo to assess thrombus at 6 month check-up.

Jasper – Echo Recheck – 6 months Jasper doing exceptionally well BP – 140, chext x-rays no change Jasper declined all other diagnostics, without deep sedation/anesthesia May never do BUN, Electrolytes, recheck echo Long Term Follow-up Jasper still doing well 18 months later On lasix & enalapril only

Hypertrophic Cardiomyopathy Clinical Characteristics Diastolic dysfunction – heart does not fill well Poor cardiac perfusion Most severe disease in young to middle aged male catss Can present as –Murmur on physical exam –Heart failure (often advanced at first sign) –Acute death –Saddle thrombus

Hypertrophic Cardiomyopathy Radiographic Findings + LV enlargement –Elevated trachea, increased VHS LA + RA enlargement seen on VD in cats + LHF –Pleural effusion –Pulmonary edema –Lobar veins >> ateries

Hypertrophic Cardiomyopathy Echocardiographic Abnormalities LV and/or IVS thicker than 6 mm in diastole Symmetrical or asymmetrical Can be only a thick IVS Can be primarily very thick papillary muscles LVIDD usually normal to slightly reduced FS normal to increased, unless myocardial failure developing LVIDS sometimes 0 mm

Hypertrophic Cardiomyopathy Echocardiographic Abnormalities LA often enlarged RA sometimes also enlarged “Smoke” can be seen in the LA Rarely a thrombus in the LA Transesophageal US more sensitive at detecting LA thrombi Borderline thickened LV should not be diagnosed as HCM without LA enlargement

Hypertrophic Cardiomyopathy DDx LV thickening Hypertension Hyperthyroidism (Chronic renal failure) Only HCM causes severe thickening of LV Dogs can rarely have HCM Cocker spaniels

Hypertrophic Cardiomyopathy Treatment Manage heart failure –Therapeutic thoracocentesis in a crisis –Diuretics –ACE inhibitors Beta blockers – if persistent tachycardia Calcium channel blockers – if thickening significant Treat hypertension if present

Hypertrophic Cardiomyopathy Treatment Q6month rechecks –Chest x-rays –CBC, GHP, electrolytes, blood gases –ECG if arrhythmia ausculted or syncope –BP Sooner if RR >40 at rest Sooner if any open mouth breathing ever

Hypertrophic Cardiomyopathy Prognosis Q6month rechecks –Chest x-rays –CBC, GHP, electrolytes, blood gases –ECG if arrhythmia ausculted or syncope –BP Sooner if RR >40 at rest Sooner if any open mouth breathing ever

Hypertrophic Cardiomyopathy Screening Genetic test is available at Washington State U – Auscultation not always sensitive Echocardiogram can detect early in breeds predisposed No evidence that early intervention changes outcome

Hypertrophic Cardiomyopathy HOCM with SAM Hypertrophic Obstructive Cardiomyopathy Systolic Anterior Motion The septal leaflet of the mitral valve is sucked into the LVOT instead of moving back toward the atria during systole If it happens intermittently, it can cause an intermittent murmur

Ginger 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

Ginger Exam Dark maroon oral mucous membranes Rear foot pads cyanotic Split S2 Neurologic exam normal, except dull mental status Differential Diagnosis - cyanosis Respiratory hypoxia Cardiac hypoxia

Ginger 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

Ginger Arterial blood gases pO 2 – 55 mmHg pCO 2 – 38 mmHg all else normal Pulse oximetry Lip – O 2 sat 89% Vulva - O 2 sat 67%

Ginger Thoracic radiographs Normal great vessels Normal heart size (VHS 9.5) aortic bulge on VD No evidence of severe respiratory disease which might cause hypoxia No evidence of heart failure

Ginger ECG S wave mildly deep in leads I,, II, III, aVF MEA 90 o Arrhythmia doesn’t seem likely Differential Diagnoses Right to left shunt Pulmonary hypertension

Ginger Right to Left Shunt Reverse PDA –Eisenmeinger’s physiology Tetralogy of Fallot AV fistula with pulmonary hypertension Echocardiogram RV thickening RV normally thinner than LV No PDA seen without Doppler

Ginger 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 Watch for bubbles on the left False negatives when bubbles disperse quickly

Ginger 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 Watch for bubbles on the left False negatives when bubbles disperse quickly

Reverse 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 PDA Treatment 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 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 PDA Prognosis Can do well short term Poor prognosis long term –Survival months to a year or two Phlebotomy interval is progressively shorter

Gabby 6 month female DSH Presented for OHE Exam - HR 100 No other abnormal findings

Gabby ECG Heart rate – 100 per minute – QRS complexes –170 per minute – P waves Rhythm – no consistent PR interval –P and QRS complexes are disassociated, but each regular All other measurements normal 3 rd degree AV block

Treatment- cats Avoid drugs that increase vagal tone –Alpha blockers – Domitor, Rompun Often no treatment needed for cats –AV node pacemaker is 100 per minute –AV node pacemaker is per minuted in the dog Surgery can be supported with temporary pacemaker in cats

3 rd degree AV block Treatment and Prognosis - Dogs Usually presents for syncope “Cannon wave” jugular pulses Treated with pacemaker implantation Drug therapy not usually successful –Usually no response to atropine –Atropine often makes 2 nd degree block go away –Some have tried theophylline Prognosis poor without pacemaker If lactate is high, emergency pacemaker is needed