Practical Cardiology Case Studies Wendy Blount, DVM Nacogdoches TX

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 (heart sounds) 3/6 holosystolic murmur loudest at left apex Mucous membranes pale pink Crackles in the small airways Pulses weak, somewhat irregular, no pulse deficits CRT 3.5-4 seconds

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

Daisy CBC, mini-panel, electrolytes Normal

Daisy CBC, mini-panel, electrolytes Normal

Daisy CBC, mini-panel, electrolytes Normal

Daisy CBC, mini-panel, electrolytes Normal Thoracic radiographs Markedly enlarged LA Compressed left mainstem bronchus Perihilar edema Vertebral heart score 11.75 Elevated trachea – LV enlargement Right heart enlargement, enlarged pulmonary lobar aa. Mildly enlarged liver Enlarged caudal vena cava

Daisy ECG

Daisy Calculating Instantaneous Heart Rate (iHR) Measure R wave to R wave (9mm) Divide by paper speed (25 mm/sec) for time per beat 9mm x _sec_ = 0.36 sec per heart beat 25mm Calculate beats per minute _heart beat_ x _60 sec = 166 beats/minute 0.36 sec minute

Daisy ECG Rate – 110 bpm Rhythm – sinus arrhythmia with VPCs MEA – normal (lead II has tallest R waves) P, QRS and T waves – normal No evidence of enlarged LA and LV on the ECG VPC – abnormal QRS Comes too early (166 bpm) Wide and bizarre shape Not preceded by a P wave T wave opposite in polarity than normal QRS

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 When to treat VPCs VPCs unusual for MR Did not treat in this case, because: MR dogs not predisposed to sudden death SAS and DCM are most common causes of sudden death due to arrhythmia Ectopic focus not firing at a fast rate (166 bpm) <200 bpm iHR is well away from the T wave No pulse deficits – did not affect hemodynamics Primary treatments for VPC are Sotalol or B blocker Negative inotropes not ideal for myocardial failure

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

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 Recheck – 1 week 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 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 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 18.75 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 30-40 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 – 1 week Clinically much improved – respiratory rate 30-40 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

Daisy Bloodwork CBC, electrolytes normal BUN 105, creat 2.1 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) LV looks big Short Axis – LV papillary muscles IVSTD – 6.0 mm – low normal LVIDD – 35 mm (n 20.2-25) LVPWD – 4.3 mm – low normal IVSTS – 9.4 mm – normal LVIDS – 25 mm (n 11.1-14.6) LVPWS – 8.4 mm - normal

Daisy - Echo Short Axis – LV papillary muscles IVSTD – 6.0 mm – low normal LVIDD – 35 mm (n 20.2-25) LVPWD – 4.3 mm – low normal IVSTS – 9.4 mm – normal LVIDS – 25 mm (n 11.1-14.6) 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 12.8-15.6) LA/Ao = 2.5 (n 0.8-1.3)

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

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

Daisy - Echo Long View – 4 Chamber LV and LA both appear large MV is very thick and knobby, with some prolapse into the LA Pulmonary vein markedly enlarged Long View – LVOT Large LA, Large LV (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 18.75 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 - 125 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 possible but rare LHF and/or RHF can result Right heart enlargement can develop due to pulmonary hypertension, in turn 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: (doppler echo) 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 – “MV flail” (video) 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

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

Chronic MV Disease Classification of Chronic AV Valve Disease Class I - small, discrete nodules along the edge of the valve leaflets Class II - free edges are thickened and the edges of the leaflets become irregular. Some CT are thickened. Class III - valve edges grossly thickened and nodular, extending to the base of the valve leaflets. There is redundant tissue, resulting in prolapse into the LA. CT are thickened and may rupture, resulting in mitral valve flail. CT to the septal leaflet can also elongate.

Chronic MV Disease LA Jet Lesions fibrous plaques in the endocardium in a region subjected to the impact of the high velocity MR jet. Endomyocardial splits or tears may also be identified. On occasion, a full thickness left atrial tear occurs resulting in hemopericardium, pericardial tamponade, and usually death. Rarely, a full thickness endomyocardial tear will involve the interatrial septum, causing an acquired atrial septal defect. (MR Client Handout)

MVD in Cavaliers Leading cause of death in Cavaliers CHF can develop as young as 1-3 years old First sign of disease is mitral murmur Careful annual auscultation Radiographs should be done as soon as murmur is detected q6months when progressing annually for stable disease Sooner when respiratory rate exceeds 40 per minute Doppler Echo when abnormalities are present on rads

MVD in Cavaliers The median survival period from grade III CHF due to MVD is approximately seven months, with 75% of the dogs dead by one year Current recommendation is that no Cavalier be bred until after 5 years of age, with no murmur At this time, a majority of Cavaliers are affected Many progress to grade II CHF (Client Handout)

Susie Signalment 12 year old spayed miniature schnauzer Chief Complaint Episodes of Confusion Exam G3 dental tartar Alternating periods of normal heart rate, tachycardia and bradycardia Pulse deficits during tachycardia

Susie Work-up CBC, panel, electrolytes, UA normal Chest x-rays

Enlarged main pulmonary artery Susie Work-up CBC, panel, electrolytes, UA normal Chest x-rays Vertebral Heart Size = 10.7 (normal 8.5-10.5) Enlarged main pulmonary artery

Susie Work-up CBC, panel, electrolytes, UA normal Chest x-rays Susie is not on heartworm prevention

Susie Work-up CBC, panel, electrolytes, UA normal Chest x-rays Susie is not on heartworm prevention

Susie ECG Heart Rate Very erratic an impossible to estimate >200 bpm for periods of up to 2-4 seconds Some periods of normal heart rate Periods of asystole for up to 2-4 seconds 25 mm/sec

Susie ECG Rhythm – arrhythmia P wave (normal 1 box wide x 4 boxes tall) Some P waves missing and some inverted Wandering pacemaker, failure of pacemaker and acceleration of pacemaker in the SA node 25 mm/sec

Susie ECG PR interval – regular and normal QRS and T waves - normal 25 mm/sec

Susie ECG Period of asystole nearly 5 seconds long Asystole longer than 2 seconds which resolves is aborted death 25 mm/sec

Susie ECG Period of asystole nearly 5 seconds long, Asystole longer than 2 seconds which resolves is aborted death 25 mm/sec

Susie ECG Period of asystole nearly 5 seconds long, Asystole longer than 2 seconds which resolves is aborted death

Diagnosis: Sick Sinus Syndrome Susie ECG Period of asystole nearly 5 seconds long, ended by an escape beat from the AV node Asystole longer than 2 seconds which resolves is aborted death Diagnosis: Sick Sinus Syndrome 25 mm/sec

Sick Sinus Syndrome Periods of sinus arrest up to several seconds in length Alternated with supraventricular tachycardia Causes of sinus arrest A dying SA node (Sick Sinus Syndrome) Markedly increased vagal tone AV node is often also abnormal Normally escapes within 1 to 1.5 seconds (automaticity 40-60/min) Diagnosis Give atropine to rule out increased vagal tone If no change, diagnosis is Sick Sinus Syndrome

Sick Sinus Syndrome Treatment Early in disease, may be responsive to atropine Atropine 0.04 mg/kg PO TID-QID – compounded w/ sweet syrup Not quite as effective: Propantheline Isopropamide Darbazine - prochlorperazine plus isopropamide Mild side effects - mydriasis and constipation Pacemaker usually eventually required to control syncope

Sick Sinus Syndrome Treatment Pacemaker usually eventually required to control syncope Possible complications of pacemaker implantation infection Lead dislodgement Head and neck muscle twitch Unknown generator life requiring replacement Failure of sinus recovery if the pacemaker fails

Sick Sinus Syndrome Treatment Pacemaker usually eventually required to control syncope Possible complications of pacemaker implantation infection Lead dislodgement Head and neck muscle twitch Unknown generator life requiring replacement Failure of sinus recovery if the pacemaker fails

Sick Sinus Syndrome Treatment Pacemaker usually eventually required to control syncope Possible complications of pacemaker implantation infection Lead dislodgement Head and neck muscle twitch Unknown generator life requiring replacement Failure of sinus recovery if the pacemaker fails

Sick Sinus Syndrome Treatment Pacemaker usually eventually required to control syncope Possible complications of pacemaker implantation infection Lead dislodgement Head and neck muscle twitch Unknown generator life requiring replacement Failure of sinus recovery if the pacemaker fails

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 sounds well – muffled (audio)

Jasper Immediate Diagnostic Plan: Lasix 25 mg IM – then in oxygen cage When RR <50, lateral thoracic radiograph

Jasper Immediate Diagnostic Plan: Lasix 25 mg IM – then in oxygen cage When RR <50, lateral thoracic radiograph

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)

Jasper Initial Therapeutic Plan: Thoracocentesis Tapped both right and left thoraces 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 1.033 Color- pink before spun, white after Clarity – opaque Nucleated cells 8500/ml RBC 130,000/ml HCT 0.7%

Jasper Initial Diagnostic Plan: Fluid analysis Chylothorax 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, T4 – normal except Glucose 134 (n 70-125) Cholesterol 193 & TG 137 (both normal) Chest X-rays Post-tap chest x-rays

Jasper Bloodwork Occult Heartworm Test - negative CBC – normal GHP – Glucose 134 (n 70-125) 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 No abnormalities noted Short Axis – LV PM

Jasper – Echo Short Axis – LV apex No abnormalities noted Short Axis – LV PM

Jasper – Echo Short Axis – LV apex No abnormalities noted Short Axis – LV PM 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

Jasper – Echo Short Axis – MV No abnormalities noted Short Axis – Ao/RVOT

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

Jasper – Echo Short Axis – PA Difficult to evaluate due to “rib shadows” Long Axis – 4 Chamber

Jasper – Echo Short Axis – PA Difficult to evaluate due to “rib shadows” Long Axis – 4 Chamber

Jasper – Echo Short Axis – PA Difficult to evaluate due to “rib shadows” Long Axis – 4 Chamber

Jasper – Echo Short Axis – PA Difficult to evaluate due to “rib shadows” Long Axis – 4 Chamber

Jasper – Echo Short Axis – PA Difficult to evaluate due to “rib shadows” Long Axis – 4 Chamber

Jasper – Echo Short Axis – PA Difficult to evaluate due to “rib shadows” Long Axis – 4 Chamber

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 0.8-1.3)

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 18.75 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 – Echo Recheck – 1 week Jasper doing exceptionally well –back to normal. Lateral chest radiograph

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, chest x-rays no change Jasper declined all other diagnostics, without deep sedation/anesthesia May never do BUN, Electrolytes, recheck echo

Jasper – Echo Long Term Follow-up Jasper still doing well 18 months later On lasix & enalapril only At 2 years, owners decided Jasper didn’t need heart meds anymore, so they stopped giving them Jasper was asymptomatic for one year after that Attacked and killed by dogs 3 years after initial diagnosis On necropsy, Jasper’s heart weighed 31g The normal adult cat heart should be <20g

Hypertrophic Cardiomyopathy Clinical Characteristics Diastolic dysfunction – heart does not fill well Poor cardiac perfusion Most severe disease in young to middle aged male cats 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 >> arteries

Hypertrophic Cardiomyopathy Echocardiographic Abnormalities Echo required in order to make diagnosis LV and/or IVS thicker than 8-10 mm in diastole Symmetrical or asymmetrical only a thick IVS (video) primarily very thick papillary muscles (video) Primarily apical

Hypertrophic Cardiomyopathy Echocardiographic Abnormalities Echo required in order to make diagnosis LV and/or IVS thicker than 8-10 mm in diastole Symmetrical or asymmetrical only a thick IVS (video) primarily very thick papillary muscles (video) Primarily apical

Hypertrophic Cardiomyopathy Echocardiographic Abnormalities Echo required in order to make diagnosis LV and/or IVS thicker than 9-10 mm in diastole Symmetrical or asymmetrical only a thick IVS (video) primarily very thick papillary muscles (video) Primarily apical LVIDD usually normal to slightly reduced FS normal to increased, unless myocardial failure developing (Jasper) LVIDS sometimes 0 mm

Hypertrophic Cardiomyopathy Echocardiographic Abnormalities LA often enlarged RA sometimes also enlarged “Smoke” may 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 Echocardiographic Abnormalities HOCM with SAM Hypertrophic Obstructive CardioMyopathy with Systolic Anterior Motion Septal leaflet of the MV get sucked up into the LVOT during systole rather than closing the MV caudally Results in two compounded systolic murmurs Aortic turbulence due to functional SAS Mitral regurgitation SAM and its murmur can be intermittent (video B mode) (video Doppler)

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 Follow-Up 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 http://www.vetmed.wsu.edu/deptsvcgl/ Auscultation not always sensitive Echocardiogram can detect early in breeds predisposed No evidence that early intervention changes outcome (Client Handout)

Pleural Effusion Usually caused by biventricular failure in the dog Parietal pleura veins drain into the R heart like the systemic veins Visceral pleura veins drain into the L heart with the pulmonary veins RHF alone can cause pleural effusion in dogs LHF alone almost never causes pleural effusion in dogs, but often does in cats Cats in LHF will often have pleural effusion but no ascites Dogs in RHF will often have pleural effusion and ascites