Download Jake - wendyblount.com

Practical Cardiology
Case Studies
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 101.4
• Mucous membranes pink, CRT 3.5 seconds
• Subtle dependent edema on the lower legs
• Jugular veins distended
• 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
Diagnostic Plan (B Client)
• Blood Pressure
– 150 mm Hg systolic (Doppler)
• Chest x-rays
Jake
Jake
Jake
Diagnostic Plan (B Client)
• 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 – 2nd Wave (2 pm)
• EKG
Jake
Diagnostic Plan – 2nd Wave (2 pm)
• EKG
• Rate – 140 bpm
• Rhythm – sinus rhythm – P wave abnormal
–
–
–
–
–
Early and upside down
Followed by a normal QRS
Occurring 5 times a minute
APC – Atrial Premature Contractions
Supraventricular premature contractions
Jake
Diagnostic Plan – 2nd Wave (2 pm)
• EKG
• Echocardiogram (video)
(another 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 10.8-12.3)
LVIDD – 72.1 mm (n 43-48)
LVPWD – 15.1 mm (n 8.7-10)
IVSTS – 11.9 mm (n 16.5-18.1)
LVIDS – 67.1 mm (n 27.4-30.4)
LVPWS – 13.0 mm (n 14-15.6)
FS = LVIDD – LVIDS
LVIDD
(72.1-67.1)/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 27.4-30.4)
• LAD – 44.7 mm (n 25.8-28.4)
• LA:Ao = 44.7/23.1 = 1.9 (n 0.8-1.3)
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
Jake – Dx & Tx
Recommendations
• Congestive Heart Failure
–
–
–
–
–
CBC, serum panel and electrolytes
Furosemide 80 mg PO BID
Enalapril 20 mg PO BID
Recheck mini-panel and electrolytes in 3-5 days
Recheck chest rads and BP 3-5 days
• Dilated Cardiomyopathy
–
–
–
–
Thyroid panel (TSH, T4, FreeT4)
Pimobendan 10 mg PO BID (declined)
Carnitine 2 g PO BID
Recheck echo, chest rads, BP, EKG, mini-panel/lytes 60
days (sooner if respiratory rate >40 at rest)
Jake - Bloodwork
Carnitine for DCM
– Boxers with genetic defect need extra carnitine
– Plasma levels have low sensitivity
– Myocardial biopsy is usually required
CBC, Mini-panel - BUN, creat, glucose, TP, SAP, ALT
• Normal
Electrolytes, Thyroid panel
• 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
• Heart sounds (audio file)
– Chaotic heart sounds with pulse deficits on
auscultation
– “tennis shoes in a dryer”
– Called “Delirium cordis”
Jake – Follow-Up
25 mm/sec
•Heart Rate
•200 bpm (tachycardia)
•Rhythm (NSR, RSA or arrhythmia)
•irregularly irregular - arrhythmia
Jake – Follow-Up
• P wave
(normal 1 box wide x 4 boxes tall)
• not present
• PR interval (normal 1.5-3.25 boxes)
• no P wave – can’t measure
• QRS
(normal 1.5 boxes wide x 30 boxes tall)
• 2 boxes wide x 26 boxes tall
• Wide QRS = LV enlargement
Diagnosis – Atrial Fibrillation
25 mm/sec
Jake – Treatment
• Recommended treatment
• Pimobendan for DCM (declined before)
• Digitalis for Afib
• Treatment was declined, and Jake was euthanatized 1
week later
• Most dogs with DCM are gone within 3 months of becoming
symptomatic, if treated with furosemide & ACE.
• Survival is likely much shorter – days to weeks – if untreated.
• Adding Pimobendan increases mean survival to 130 days.
• Median survival for dogs with DCM and Afib is 3 weeks,
without Pimobendan
Dilated Cardiomyopathy
Common Signalment
• Breed
–
–
–
–
–
–
–
Doberman
Great Dane
Boxer
Newfoundland
Portuguese Water Dog
Dalmatian
Cocker Spaniel
• No genetic test at this time
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
• Vegetarian diet (historical)
Dilated Cardiomyopathy
Common Historical and PE findings
• Chemotherapy
– doxorubicin
• DCM in a puppy
– Parvovirus at 2-4 weesk of age (historical)
– Chaga’s Disease
• Trypanosoma cruzi
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 ECG Findings
• Wide P wave
– LA enlargement
• Tall R wave
– LV enlargement
• Atrial fibrillation
• VPCs
• Ventricular arrhythmias
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
Treatment
• Pimobendan 0.2-0.3 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
–
–
–
–
–
–
250-500 mg PO BID
Cats fed low taurine diets, or with genetic defect
American cocker spaniels, Newfoundlands
Dogs fed vegetarian diets
Large and giant breed dogs fed lamb and rice diet
Almost never Great Danes and Dobermans
• Carnitine – 500-1000mg PO BID
– Boxers with genetic defect
– Plasma levels have low sensitivity
– Myocardial biopsy is usually required
• Thyroxine – if hypothyroid
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
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
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.
– Interpretation of echo in mildly effected dogs can be challenging
• Some think a Holter monitor is more effective screening
– Especially for Boxers
• No one knows whether early intervention changes
outcome.
(handout)
Atrial Fibrillation
What is it?
– Disorganized contraction of the atria
– Absence of effective atrial contractions
– AV node is bombarded
• Impulse makes it through to ventricles irregularly
• “irregularly irregular” rhythm
– Irregular ventricular rhythm
• More obvious at lower heart rates
– Irregular intensity of heart sounds due to erratic filling time
and volume
• More obvious at higher heart rates
• Pulse strength irregular with deficits
Atrial Fibrillation
What causes it?
– Anything that can cause enlarged LA
• Most common cause is DCM in dogs
• Also end stage MR progressing to myocardial failure
– Occasionally can be primary in very large dogs
• Very rare without underlying heart disease
– Less common in cats
• Advanced HCM with huge LA
Frequent APCs are a harbinger of Afib
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 0.1-0.2 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!!
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
• Can attempt in big dogs with normal hearts and primary
Afib, not dogs with DCM
– Can try medical conversion with quinidine
– Or Anesthesia and conversion with electric shock
Atrial Fibrillation
Atrial Fibrillation
Atrial Fibrillation
Boxer Cardiomyopathy
• Can be primarily ventricular arrhythmia
– VPCs or bursts of Vtach
• 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
• Holter Monitor is more likely to diagnose than
echocardiogram
Ventricular Arrhythmias
When do you treat?
• Class I antiarrhythmics
– Procainamide, quinidine
– Do not prevent sudden death in people
– In some cases increase risk of sudden death
• Beta Blockers
– High doses required to prevent sudden death
– Not tolerated by dogs with severe DCM
• Calcium channel blockers not effective for ventricular
tachyarrhythmias
• Sotolol is often the drug of choice, as long as
myocardial failure not severe
Ventricular Arrhythmias
When do you treat?
• Amioderone
–
–
–
–
Another class III antiarrhythmic
Unpredictable pharmacokinetics
Significant toxicity
Been around since 1961
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
• (auscultation)
• Crackles in the small airways, especially at peak
inspiration
• Pronounced respiratory sinus arrhythmia
• 2/6 systolic murmur PMI left apex
• 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
Differential Diagnoses - Cough
• Chronic Bronchitis
• Collapsing trachea
Diagnostic Plan - initial
• Chest and cervical x-rays
• Inspiratory - VD and right lateral
• Expiratory - left lateral
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 – 2nd 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)
• 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
Chronic Bronchitis
•
•
•
•
•
•
•
Crackles in the lungs do not always mean pulmonary edema
If there is no murmur, CHF is very unlikely
If there is RSA, CHF is very unlikely
Always take a chest x-ray
Can lead to airway collapse over time
If not doing well, never hesitate to repeat chest x-rays
Mainstay of therapy is corticosteroids and cough
suppressants
• Antibiotics periodically for secondary infection
– Can be seeded by periodontal infection
• Guided by TTW/BAL and culture & sensitivity
– This procedure can decompensate a dog with collapsing trachea
– As can intubation for dental cleaning
Chronic Bronchitis
• CB dogs are well dogs that cough
– CHF dogs are sick dogs that cough
• Weight loss can improve quality of life tremendously if
overweight
• There is the rare dog that needs to live on rotating antibiotics
to avoid bronchopneumonia
– Pick three, rotate and do C&S when efficacy wanes
•
•
•
•
Don’t forget about hyperadrenocorticism
Deworm
Consider allergy testing and hyposensitization
If all else fails, bronchoscopy might help
Chronic Bronchitis
Treatment
• Corticosteroids and cough suppressants to reduce cough by 80%
• Bronchodilators – beta agonists if no heart failure,
methylxanthines
• Inhaled steroids and/or bronchodilators minimize side effects
• Monitor blood pressure to make sure bronchodilators tolerated
• Mucolytics can help if phlegm is thick and copious
• If patient becomes refractory to treatment without collapsing
airways, consider referring for doppler echo
– Pulmonary hypertension due to chronic COPD
– Sildenafil can sometimes give short term relief
Chronic Bronchitis
Cough suppressants
• Hydrocodone
• guaifenasin + dextromethorphan tabs
• promethazine (Phenergen)
• Maropitant (Cerenia)
• Tramadol
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
• Most helpful in dogs with airway disease and a murmur
• Often more helpful in cats whose thoracic rads can be
more ambiguous
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 - 120
Dx – atrial standstill,
• Rhythm – regular
L ventricular escape rhythm
• no P waves
• QRS – deep S wave, wide, bizarre QRS
Tom
Electrolyte panel
• K 10.9 mEq/L, iCa++ 0.96 mmol/L
• pH 7.08, HCO3 11 mEq/L
• Grapefruit sized very firm bladder
Tom
Treatment
•
•
•
•
Place indwelling urinary catheter & 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
Tom
• ECG 2 – 6 minutes later
Tom
ECG 2 – 6 minutes later
• Heart rate 140
• No P waves
• QRS less abnormal
• T wave not as tall
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
Tom
ECG 4 – 2 hours after presentation – T 98.9
• Heart rate 120, normal sinus rhythm
• P waves have returned, but wide and inverted
• QRS and T normal
Tom
ECG 5 – 5 hours after presentation
• Heart rate 130
• Normal sinus rhythm
• P waves have returned to normal
Tom
Follow-up electrolytes
• iCa++ normal, K 6.6 mEq/L
• HCO3-- 16.3 mEq/L, pH 7.29
Tom began eating the next day, the urinary
catheter was removed, and he was
discharged 2 days later.
• He was azotemic on presentation, but this
resolved with treatment
• Treatment by Arrhythmia
• Antiarrhythmic Drug
Classes and Doses
• Arrhythmia Description
and Classification