Cardiomyopathies Flashcards
T/F: Cardiomyopathy is usually related to CAD, HTN, or a Valve Disorder.
False.
Usually due to a genetic condition.
-Associated with mechanical and/or electrical dysfunction
-Hypertrophy or Dilation
What is Primary Cardiomyopathy?
Genetic, mixed or acquired.
-Exclusively confined to heart muscle
-Ex: HCM, DCM, peripartum
What is Secondary Cardiomyopathy?
Usually in context of multiorgan dysfunction.
-Amyloidosis, drug induced, sarcoidosis
-Something has caused it.
-The most common genetic CV disease
-An autosomal dominant disorder
-LV hypertrophy in the absence of any other cardiac disease
-Can affect people of all ages
-Prevalence of 1 in 500 people
Hypertrophic Cardiomyopathy aka
Idiopathic hypertrophic subaortic stenosis (IHSS)
Describe the pathophysiology of Hypertrophic Cardiomyopathy.
-Myocardial Hypertrophy leads to large interventricular septum.
-Dynamic LVOT obstruction: accelerated blood flow through narrowed LVOT leads to Venturi effect.
-Systolic Anterior Movement (SAM) of Mitral valve: During systole, piece of the Mitral Valve flips back and can cause obstruction. decreases blood flow leading to sudden death.
-Diastolic Dysfunction
-Myocardial Ischemia: Abnormal coronaries, large ventricular mass, inc. LVEDP->dec. Subendocardial coronary perfusion. Coronaries cannot perfuse these thick muscles.
-Dysrhythmias: exacerbated by exercise. Can lead to sudden death.
What are the S/Sx of Hypertrophic Cardiomyopathy?
Usually go from asymptomatic to sudden death.
-If they do have symptoms, will be S/Sx of HF
-Angina, fatigue, syncope, tachydysrhythmias, HF
-Lying down relieves symptoms (dec. LVOTO)
-Valsalva aggravates them
-Murmur present, gallop rhythm
-Sudden death most likely aged 10-30 years
-No competitive sports
How do you diagnose Hypertrophic Cardiomyopathy?
-ECG shows LVH, QRS and ST alterations
-Echo shows hypertrophy, LVOTO, SAM, cavity obliteration during systole, MR, EF >80% (EF is high because no blood is left behind in the heart after it beats)
-SAM- Systolic anterior movement of anterior leaflet of mitral valve (MR from Venturi effect)
-Histology features hypertrophied myocardial cells and areas of patchy scarring
-Definitive diagnosis with endomyocardial biopsy and DNA analysis
What key words diagnose Hypertrophic Cardiomyopathy on an endomyocardial biopsy?
Myofibrillar Disarray
What are the treatment goals for Hypertrophic Cardiomyopathy?
-improve diastolic filling
-reduce LVOT obstruction
-decrease myocardial ischemia
What is the treatment for mild symptoms of Hypertrophic Cardiomyopathy?
-Beta blockers
-Calcium Channel Blockers
-Possible diuretics if S/Sx of CHF
What are the interventions for high risk patients with Hypertrophic Cardiomyopathy?
-Amiodarone (afib is common)
-ICD
What are the treatments for HF due to Hypertrophic Cardiomyopathy?
1) Non-obstructive – drug therapy or transplant
2) Obstructive – drug therapy, surgical myomectomy or pacing (desynchronize the heart to dec LVOTO)
3) Alcohol sclerosing of the septal perforating arteries (cath lab)
What is the surgical treatment for Hypertrophic Cardiomyopathy?
Considered in 5% of patients with SEVERE disease
-Myomectomy (remove pieces of ventricle/septum inside of heart)
-MV replacement (mechanical valve - can’t have LVOT obstruction with a mechanical valve)
What is the prognosis of Hypertrophic Cardiomyopathy?
-Overall annual mortality is 1%
-If there is family history of malignant arrhythmias or sudden death it is 5%
How can you minimize LVOT obstruction?
-decrease contractility
-increase preload
-increase afterload
What things worsen LVOT obstruction?
SNS stimulation, hypovolemia and vasodilation
What should you assess preop for a patient with HCM?
-Cardiac eval, ECG, echo, continue meds, turn off ICD, apply R2 pads
-Ask all patients if they or family members have hx of sudden death
-Systolic murmur should raise suspicion of HCM
-Anxiolytics to blunt SNS
Describe HD goals for management of HCM
Slow, Tight, Full, Dec Contractility
Describe anesthetic management of HCM
-Blunt SNS to DL (deep on gas, consider BB with DL)
-Beta antagonists are good at decreasing SNS stimulation and slowing HR
-Invasive BP and echo (depending on case)
-Use NEO!
-Avoid Beta agonists (ephedrine, dopa) due to increasing contractility and HR will worsen LVOTO
-NO Vasodilators (dec. SVR will worsen LVOT obs. )
-Maintain NSR, Treat SVT quickly
-PPV can dec. Preload and worsen LVOTO
-Smaller TV and inc. RR
-Avoid Peep
I-nsufflation can worsen LVOT obstruction (dec. Preload)
-Insuflate slowly and dec. Insufflation pressure
Describe HCM in a parturient patient.
-Pregnancy is usually well tolerated
-Challenge with labor - usually get scheduled C/S
-Pain increases catecholamine release
-Bearing down (valsalva) increases LVOT obstruction
-Regional is OK
-Euvolemia or slight hypervolemia is helpful
-Use Neo for HOTN
-Use care with oxytocin due to vasodilating effects
-Pulmonary edema post delivery can be seen (Delicate fluid balance)
Describe postop mgmt of HCM
All factors that stimulate SNS must be avoided:
-Pain, shivering, anxiety, hypoxia, hypercarbia
Maintenance of euvolemia and prompt treatment of HOTN.
What is Dilated Cardiomyopathy?
The most common type of CM.
-A primary myocardial, LV or biventricular dysfunction, systolic dysfunction, normal wall thickness
-Many different causes
What are the different causes of Dilated CM?
-genetics
-viruses
-ETOH
-cocaine
-peripartum
-HIV
-Duchenne’s MD
-thyroid
-chemotherapy, radiation
-hypertension, CAD, valve disease
What are the S/Sx of Dilated CM?
-Heart failure, exertional angina
-Functional Mitral or tricuspid regurgitation: Ventricular dilation leads to valve regurg
-SVT and ventricular dysrhythmias common
-Sudden death can occur
-Systemic embolization: Mural thrombi form in hypokinetic chambers (leads to TIA, strokes, etc)
-Diagnosed by EKG, Chest xray, Echo showing global hypokinesis and sometimes thrombi
What is the prognosis of dilated CM?
-5 year mortality of 50%
-Alcoholic is reversible with abstinence
Describe Anesthetic Mgmt of Dilated CM?
-Same as that of CHF
-AICD and OHT common
-Regional anesthesia is well tolerated (check anticoagulation status)
What is Apical Ballooning Syndrome?
-Stress induced cardiomyopathy, “broken heart” syndrome
-Physical (acute asthma, surgery, stroke) or emotional stress
-Temporary disruption of contractility at LV apex
-Apical ballooning seen on ECHO
-SxS: chest pain and dyspnea
-Treatment is supportive (medical mgmt, IABP)
What is Peripartum CM?
-Rare form of Dilated CM of unknown cause
-Usually in 3rd trimester-5 months after delivery
-Women with no history of heart disease
-Risk factors: obese, multiparity, >30 years of age, twins , preeclampsia, AA
-Symptoms like normal pregnancy-DOE, ankle swelling
-Diagnosis – Echo; EF <45% around delivery
-Prognosis: mortality of 25-50% within 3 months of delivery
Describe Mgmt of Peripartum CM
-Treat like HF- diuretics, vasodilators, hydralazine and nitrates. Mechanical support or OHT if severe
-Manage as you would HF; regionals are well-tolerated
What is Restrictive CM due to?
Due to myocardial infiltration and cause severe diastolic dysfunction (can’t relax)
-Mostly amyloidosis, as well as sarcoidosis, or carcinoid
-Stiffness of the myocardium due to deposition of abnormal substances
-Rigid heart that can’t fill
-Similar to restrictive pericarditis
-Affects both R & L heart; systolic fxn usually nml; thromboembolism may occur, conduction disturbances are common
How do you diagnose Restrictive CM?
Diagnosis best via echo – shows diastolic dysfunction, and “speckled” ventricle (amyloid plaque); endomyocardial biopsy confirms
How do you treat Restrictive CM?
Diastolic dysfunction WITHOUT cardiomegaly
-Treat like diastolic HF – diuretics, ICD (digoxin may cause dysrhythmias), maintain NSR (SV fixed)
-OHT is not an option with sarcoid, amyloid because plaque will recur in donated heart
-Prognosis is poor
-Treat like tamponade (fixed SV so inc HR)
What is Cor Pulmonale?
Severe Pulm HTN -> R HF.
Causes:
-COPD (most common), restrictive lung disease, obesity-hypoventilation syndrome, or primary pulmonary htn
-Chronic hypoxia causes the lung changes (pulmonary vascular remodeling)
-Hypoxia->inc. PVR->RV hypertrophy->RV failure
How do you diagnose Cor Pulmonale?
-EKG shows RAD, RBBB, and peaked P waves in leads II, III, aVf (P pulmonale)
-TEE shows increased PAP
What is the treatment for Cor Pulmonale?
Dig, lasix, O2 (goal PaO2 >60), sildenafil, lung or heart-lung transplant
Describe Anesthetic Mgmt of Cor Pulmonale
-Optimize respiratory function
-Volatiles and bronchodilators help
-Avoid respiratory depression (too much narcotic)
-Lines as needed
-Maybe TEE
-ICU after
