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

Jake Signalment 9 year old male Boxer Chief Complaint Deep cough when walking in the morning, for about one week Appetite is good

Jake Exam Weight 81.9 – has lost 5 pounds in 3 months (BCS 3) Temp Mucous membranes pink, CRT 3.5 seconds Subtle dependent edema on the lower legs Jugular veins normal Harsh lung sounds 3/6 holosystolic murmur, PMI left apex Heart rate 160 per minute Respirations 55 per minute Femoral pulses somewhat weak

Jake Differential Diagnosis - Cough Respiratory Disease Cardiovascular Disease Both

Jake Diagnostic Plan (B Client) Blood Pressure –150 mm Hg systolic (Doppler) Chest X-rays –Massively enlarged heart (VHS 12.5) –Enlarged LA, LV (dorsally elevated trachea) –Enlarged pulmonary veins –Perihilar pulmonary edema –Left congestive heart failure

Jake Immediate Therapeutic Plan (10 am) Furosemide –80 mg IM 4 hours later –Respiratory rate is 36 per minute

Jake Diagnostic Plan – 2 nd Wave (2 pm) EKG –Normal Sinus Rhythm Echocardiogram (video)video

Jake - Echo Transverse - LV Apex LV Looks Big Transverse - LV Papillary Muscles LV looks REALLY big Myocardium is hardly moving Flat papillary muscles

Jake - Echo Transverse - LV Papillary Muscles IVSTD – 9.7 mm (n ) LVIDD – 72.1 mm (n 43-48) LVPWD – 15.1 mm (n ) IVSTS – 11.9 mm (n ) LVIDS – 67.1 mm (n ) LVPWS – 13.0 mm (n ) FS = LVIDD – LVIDS LVIDD ( )/72.1 = 7% (n 30-46%) EF = 15% (n >70%)

Jake - Echo Transverse - Mitral Valve No increased thickness of MV No vegetations on the MV EPSS – 12 mm (n <6 mm) Transverse – Aortic Valve/RVOT LA at least Double Big

Jake - Echo Transverse - Aortic Valve/RVOT AoS – 23.1 mm (n ) LAD – 44.7 mm (n ) LA:Ao = 44.7/23.1 = 1.9 (n ) Transverse – Pulmonary Artery No abnormalities noted

Jake - Echo Long – 4 Chamber LV massively enlarged Poor systolic function LA 2x enlarged IVS is bowed toward the right, due to LV dilation Long – LVOT No abnormalities in LVOT (video)video

Jake – Dx & Tx Recommendations Left Congestive Heart Failure –Mini-panel and electroytes –Furosemide 80 mg PO BID –Enalapril 20 mg PO BID –Recheck mini-panel and electrolytes in 3-5 days –Recheck chest rads 3-5 days Dilated Cardiomyopathy –Pimobendan 10 mg PO BID (declined) –Carnitine 2 g PO BID –Recheck echo, chest rads, EKG, mini-panel/lytes 60 days (sooner if respiratory rate >40 at rest)

Jake - Bloodwork CBC normal Mini-panel - BUN, creat, glucose, TP, SAP, ALT Normal Electrolytes Not done

Jake – Follow-Up Recheck – 6 days BUN 30 (n 10-29) Creat normal Electrolytes not done Chest x-rays not done No additional rechecks were done, owner did not monitor respiratory rate at home

Jake – Follow-Up 4 months later… Chief complaint – –Doing well until last week –poor energy, coughing again, not eating Chaotic heart sounds with pulse deficits on auscultation –“tennis shoes in a dryer” ECG

Jake – Follow-Up ECG Heart Rate 200 bpm (tachycardia) Rhythm – irregularly irregular, no P waves, irregular pattern to PR interval P wave – not present – can not measure PR interval – no P wave – can’t measure QRS – sec x 2.6 mV ST segment - <-0.2mV depression MEA – 90 o

Dilated Cardiomyopathy Common Historical and PE findings Onset seems rather acute – signs of LHF –Coughing, dyspnea, exercise intolerance, weak pulses, poor appetite and energy Sometimes RHF also –Ascites, pleural rubs, jugular vein distension, peripheral edema, diarrhea Syncope Mitral murmur –Holosystolic, PMI left apex Chaotic heart sounds with pulse deficits if A-fib

Dilated Cardiomyopathy Common Radiographic Findings Generalized cardiomegaly - Increased VHS Enlarged LV – elevated trachea Enlarged LA – compressed left bronchus + RA/RV enlargement + Left Heart Failure – lobar veins > arteries, pulmonary edema + Right Heart Failure – enlarged caudal vena cava, ascites, pleural effusion, hepatosplenomegaly

Dilated Cardiomyopathy Common Echocardiographic Lesions Dilation of all 4 heart chambers Large LVIDD (eventually large LVIDS also) Hypokinesis of LV wall and IVS Reduced FS Paradoxical septal motion Increased EPSS Normal looking MV and TV leaflets Papillary muscle flattening

Dilated Cardiomyopathy Common ECG Findings Wide P wave Tall R wave Atrial fibrillation VPCs Ventricular arrhythmias

Dilated Cardiomyopathy Treatment Pimobendan mg/kg PO BID –Inodilator – positive inotrope and vasodilator Treat left heart failure if present –Diuretics –ACE inhibitor if tolerated 0.5 mg/kg PO SID-BID –Nitroprusside CRI if critical –Dopamine or dobutamine CRI if critical –Thoracocentesis if pleural effusion in cats –Oxygen, of course

Dilated Cardiomyopathy Treatment Furosemide boluses for fulminant LHF –80% effective –6-8 mg/kg IV Q1-2 HR UNTIL RR<50 –4 mg/kg IV q1-2h until RR<40 –4 mg/kg PO q4-6 hr until RR<30 –Then PO q6-12 hrs to maintain RR<30 –Give IM if placing IV cath might be fatal Furosemide CRI may be more effective –0.5 to 1.0 mg/kg/hr

Dilated Cardiomyopathy Treatment Monitoring fulminant LHF –Lactate (return to normal) –blood gases (resolution of acidosis and hypoxemia) –Respiratory rate –PROVIDE WATER & WATCH URINE PRODUCTION –Check electrolytes at least daily –Central line can make blood draws easy

Dilated Cardiomyopathy Treatment Taurine – if whole blood taurine levels low – mg PO BID –Cats fed low taurine diets, or with genetic defect –American cocker spaniels –Dogs fed vegetarian diets –Large and giant breed dogs fed lamb and rice diet Carnitine – mg PO BID –Boxers with genetic defect –Plasma levels have low sensitivity –Myocardial biopsy is usually required Thyroxine – if hypothyroid

Dilated Cardiomyopathy Monitoring patients in chronic LHF Chest x-rays and exam every 6 months Echocardiogram when chest x-rays change –Every 6 months with cardiomyopathies ECG when arrhythmia ausculted, syncope, or if disease which predisposed to arrhythmia –Boxer cardiomyopathy –Dilated cardiomyopathy Recheck sooner if RR at rest is >40 per minute

Dilated Cardiomyopathy Monitoring patients in chronic LHF BUN, creat –3-4 days after starting or increasing ACE inhibitor –Every 6 months when doing well –Sooner if things get worse Electrolytes and blood gases –Every 6 months when doing well –Sooner if things get worse –Potassium supplementation is often necessary –Untreated hypokalemia can predispose to arrhythmia, especially if on digitalis

Dilated Cardiomyopathy Prognosis Most dogs are done within 3 months of becoming symptomatic, if treated properly. Survival is likely much shorter – days to weeks – if untreated. Median survival for dogs with DCM and Afib is 3 weeks. All of these numbers prior to Pimobendan.

Dilated Cardiomyopathy Screening Predisposed dog breeds show decreased fractional shortening for many years prior to onset of clinical signs and/or murmur –FS has to fall <15% to cause CHF Screening by echocardiogram at young adult to middle age is effective. No one knows whether early intervention changes outcome.

Dilated Cardiomyopathy Beta Blocker Therapy Seems counterintuitive for DCM –Negative inotrope In people, chronic stimulation of B1 receptors is cardiotoxic –Improved survival when people with mycoardial failure are put on beta blockers (carvedilol) No similar success with canine DCM –Pharmakokinetics of carvedilol in dogs have been studied, and are unpredictable

Atrial Fibrillation Why Treat?? Heart rate around 250 beats per minute –Myocardial failure will result within 3-6 weeks –Ventricles can not fill properly – forward heart failure Treatment –Conversion would be ideal –But this is not easy to accomplish in very sick hearts –Big dogs with normal hearts – primary Afib –Medical conversion with quinidine –Anesthesia and conversion with electric shock

Atrial Fibrillation Treatment – Afib in unhealthy hearts –Slow the heart rate at the AV node (goal 150 bpm) –Digoxin Weak positive inotrope –Beta blockers Negative inotrope Propranolol mg/kg PO TID Titrate up to effect to 0.5 mg/kg PO TID –Calcium channel blockers Diltiazem 0.5 mg/kg PO TID (titrate up to 1.5 mg/kg) DON’T USE BETA BLOCKER AND CALCIUM CHANNEL BLOCKER TOGETHER!!

Tom 5 year old neutered male DSH Chief Complaint Outdoor cat, owners think he was hit by a car Tom is laterally recumbent, and breathing hard Exam T 96.5, P- 100, R – 66 No evidence of trauma

Tom ECG 1 Heart Rate Rhythm – regular, no P waves QRS – deep S wave, wide, bizarre QRS idioventricular rhythm i-STAT EC8+ K 10.9 mEq/L, iCa mmol/L pH 7.08, HCO 3 11 mEq/L Grapefruit sized very firm bladder

Tom Treatment Place indwelling urinary catheter Place IV catheter Begin 0.9% NaCl at 15 ml/hr 1 unit regular insulin IV 5cc 50% dextrose diluted in 15 cc fluids, given over 1 hour; added 5%dextrose to fluids ECG 2 – 6 minutes later Heart rate 140 No P waves, QRS less abnormal

Tom ECG 3 – 1 hour after presentation Heart rate 120 No change for the past 45 minutes Treatment Ca-gluconate 2cc IV slowly over 20 minutes ECG 4 – 1 hour after presentation – T 98.9 Heart rate 120 P waves have returned, normal sinus rhythm

Tom ECG 5 – 5 hours after presentation Heart rate 130 Normal sinus rhythm P waves have returned to normal i-STAT EC8+ iCa ++ normal, K 6.6 mEq/L HCO mEq/L, pH 7.29

Pockets Signalment 11 year old spayed female yorkie (5 pounds) Chief Complaint Harsh cough several times daily for 2 months History of chronic inflammatory liver disease, luxating patellas, severe chronic periodontal disease and multiple allergies; these problems clinically well managed at this time. Mammary carcinoma removed one year previously, at the time of OHE.

Pockets Exam Temp 100.3, P 110, R 26, BP 110, BCS 3.5 BAR, well hydrated, in good body condition Crackles in the small airways, especially at peak inspiration Pronounced respiratory sinus arrhythmia Normal heart sounds Pulses normal, CRT < 2 sec Mature cataract right eye

Pockets Differential Diagnoses - Cough Chronic Bronchitis Collapsing trachea Diagnostic Plan - initial Chest and cervical x-rays Inspiratory - VD and right lateral Expiratory - left lateral

Pockets Thoracic and cervical radiographs No collapse of the trachea Vertebral heart score 10 Normal cardiac silhouette and pulmonary vasculature Pronounced peribronchiolar pattern Shoulder arthritis Vertebral arthritis Normal sized liver

Pockets Diagnostics – 2 nd round Transtracheal wash Cytology – suppurative inflammation (mature neutrophils) Culture negative Treatment – Diagnosis Chronic Bronchitis Hydrocodone as needed for cough suppression Inhaled steroids PRN for cough Not tolerated – Temaril P instead

Pockets Long term outcome – 4 years (handout)handout Monitoring – chest rads every 6 months Dental cleaning every 4-6 months 1 episode of bacterial bronchpneumonia after dental, despite treatment with metronidazole Amoxicillin 1 week before and after dental Increase cough suppressants for 3 days after dental Hydrocodone almost every day Temaril P for flare-ups –Repeat transtracheal wash when severe Coughs once or twice almost every day

Daisy Signalment 15 year old spayed female mixed terrier 11 pounds Chief Complaint Became dyspneic while on vacation, as they drove over a mountain pass Come to think of it, she has been breathing hard at night for some time

Daisy Exam T 100.2, P 185, R – 66, BP – 145, BCS – 3.5 Increased respiratory effort 3/6 holosystolic murmur loudest at left apex Mucous membranes pale pink Crackles in the small airways Pulses weak CRT seconds

Daisy Differential Diagnosis - Dyspnea Suspect congestive heart failure Suspect mitral regurgitation Concurrent respiratory disease can not be ruled out Initial Diagnostic Plan Chest x-rays CBC, mini-panel, electrolytes

Daisy CBC, mini-panel, electrolytes Normal Thoracic radiographs Markedly enlarged LA Compressed left mainstem bronchus Perihilar edema Vertebral heart score Elevated trachea – LV enlargement Right heart enlargement Mildly enlarged liver

Daisy Initial Therapeutic Plan Lasix 25 mg IM, then 12.5 mg PO BID Enalapril 2.5 mg PO BID Owner is a lab tech, and set up oxygen mask to use PRN at home Recheck BUN, potassium, chest rads 3-5 days Come back sooner if respiratory rate at rest is above 40 per minute without oxygen

Daisy Recheck – 4 days Daisy’s breathing is much improved (30-40 at rest) Lateral chest x-ray Electrolytes normal BUN 52

Daisy Diagnostic Plan - updated Decrease enalapril to SID Recheck BUN 1 week Recheck chest rads 1 week Recheck – 1 week BUN – 37 Thoracic rads no change Request recheck in 3 months, or sooner if respiratory rate at rest is above 40 per minute

Daisy 2 months later Daisy is breathing hard again at night Exam Same as initial presentation Diagnostic Plan CBC, mini-panel, electrolytes Chest x-rays

Daisy Bloodwork CBC, electrolytes normal BUN 88 Therapeutic Plan Increase furosemide to mg PO BID Add hydralazine 2.5 mg PO BID Recheck chest rads, BUN, electrolytes, blood pressure 1 week

Daisy Recheck – 1 week Clinically much improved – respiratory rate per minute at rest electrolytes normal BUN 58 Blood pressure 135 Chest x-rays Recommend recheck in 3 months, or sooner if respiratory rate above 40 per minute at rest

Daisy Recheck – 6 months Daisy dyspneic again Exam Similar to last crisis – BP 90 Diagnostic Plan CBC, mini-panel, electrolytes Echocardiogram, ECG, chest x-rays

Daisy Bloodwork CBC, electrolytes normal BUN 105, creat 2.1 Chest x-rays Similar to last crisis ECG Sinus tachycardia, wide P wave

Daisy - Echo Short Axis – LV apex(video)video LV looks big Short Axis – LV papillary muscles IVSTD – 6.0 mm – low normal LVIDD – 35 mm (n ) LVPWD – 4.3 mm – low normal IVSTS – 9.4 mm – normal LVIDS – 25 mm (n ) LVPWS – 8.4 mm - normal

Daisy - Echo Short Axis – LV papillary muscles IVSTD – 6.0 mm – low normal LVIDD – 35 mm (n ) LVPWD – 4.3 mm – low normal IVSTS – 9.4 mm – normal LVIDS – 25 mm (n ) LVPWS – 8.4 mm – normal FS – (35-25)/35 = 29% (normal 30-46%)

Daisy - Echo Short Axis - MV MV leaflets hyperechoic and thickened EPSS – 8 mm (n 0-6) Short Axis – Aortic Valve/RVOT LA appears 2-3x normal size AoS – 13.0 – normal LAD – 33 mm (n ) LA/Ao = 2.5 (n )

Daisy - Echo Long View – 4 Chamber LV and LA both appear large MV is very thick and knobby, with some prolapse into the LA Long View – LVOT Large LA, Large LV(video)video

Daisy Therapeutic Plan Increase hydralazine to 5 mg PO BID Add spironolactone 12.5 mg PO BID Add pimobendan 1.25 mg PO BID Increase furosemide to mg PO TID x 2 days, then decrease to BID if respiratory rate decreases to less than 40 per minute at rest. Recheck 1 week – BUN, creat, phos, electrolytes, chest rads, BP

Daisy Recheck – 1 week Clinically improved again BP BUN 132, creat 2.6, phos 6.6 Electrolytes normal chest rads improved pulmonary edema Therapeutic Plan – Update Add aluminum hydroxide gel 2 cc PO BID

Daisy 5 Months later Coughing getting worse Chest rad show no pulmonary edema LA getting larger Therapeutic Plan – Update Add torbutrol 2.5 mg PO PRN to control cough

Daisy 18 Months after initial presentation Owner discontinue pimobendan due to GI upset 28 months after initial presentation Daisy finally took her final breath BUN >100 for 22 months

Chronic MV Disease May be accompanied by similar TV disease (80%) TV disease without MV disease is possible but rare LHF and/or RHF can result Right heart enlargement can develop due to pulmonary hypertension due to LHF Myocardial failure and CHF are not directly related

Chronic MV Disease Thoracic radiograph abnormalities: LV enlargement –Elevated trachea –increased VHS LA enlargement – often largest chamber –Compressed left bronchus + left heart failure –Pulmonary edema –Lobar veins larger than arteries

Chronic MV Disease Echo abnormalities: LA and/or RA dilation, LV and/or RV dilation Exaggerated IVS motion (toward RV in diastole) Increased FS first, then later decreased FS Thickened valve leaflets If TV only affected, left heart can appear compressed, small and perhaps artifactually thick Ruptured CT – –MV flips around in diastole –MV flies up into LA during systole –May see trailing CT, or CT floating in the LV

Chronic MV Disease ECG abnormalities: Wide or notched P wave –Enlarged LA Tall R wave –Enlarged LV Right Bundle Branch block –Wide QRS –Deep S wave Left Bundle Branch Block –Wide QRS –Tall R wave

Chronic MV Disease Right Heart Failure Medications similar to LHF Medications not as effective at eliminating fluid congestion –More effective at preventing fluid accumulation, once controlled Periodic abdominocentesis and/or pleurocentesis required Prognosis for RHF and LHF is extremely variable

NTproBNP ELISA N-terminal pro-B type Natriuretic Peptide In clinic test to distinguish cardiac from respiratory dyspnea Validated in dogs JACVIM January 2008 <210 pmol/L – more likely respiratory disease >210 pmol/L – more likely cardiac disease Falsely elevated by increased creatinine Helpful in distinguishing cardiac from respiratory dyspnea when creatinine is not elevated