Cardiomyopathy Flashcards
What are cardiomyopathies?
Disorders that involve the heart muscle itself
What is primary cardiomyopathy?
AKA
Those exclusively (or predominantly) confined to the heart muscle Intrinsic
What is secondary cardiomyopathy?
AKA?
Demonstrate pathophysiologic involvement of the heart in the context of a multiorgan disorder
Extrinsic
What is dilated cardiomyopathy?
Generalized myocardial weakness
What ventricular dysfunction occurs with dilated CM?
Biventricular dysfunction
The enlarged heart that occurs with dilated CM causes what 2 cardiac complications?
Valve insufficiency (can’t close) Dysrhythmias (conduction takes longer due to size)
What can cause dilated CM?
Can be primary or secondary
- diffuse CAD
- alcohol
- viral
- DM
- etc
What is the treatment for dilated CM similar to?
CHF treatment
What is the treatment for dilated CM?
Diuretics to keep volume overload off
Vasodilators to improve forward CO
Inotropes to strengthen muscle
Transplant once medical treatment is not enough
What is the most common type of CM?
Dilated
What is the most common reason for a heart transplant?
Dilated cardiomyopathy
What is the anesthetic management for dilated CM?
Think LV dysfunction: Avoid further myocardial depression Careful fluid titration Optimal filling pressure Avoid increase in SVR
What is restrictive CM?
Heart muscle is infiltrated by abnormal tissue
What usually causes restrictive CM? What is the most common cause
Connective tissue disease
Amylidosis
Describe the heart in a restrictive CM patient?
Stiff
Noncompliant
Difficult to fill
No cardiomegaly
What 2 things are important about the heart in a restrictive CM patient?
SR
Atrial kick
What is restrictive CM clinically similar to?
Cardiac tamponade
What is the least common CM?
Restrictive CM
What is important to keep in mind about restrictive CM being similar to cardiac tamponade?
HR is important!
-it’s the only thing keeping forward flow
Are restrictive CM patients transplant candidates?
No
Because it’s a secondary process, the connective tissue disorder will infiltrate the transplanted heart
What is hypertrophic CM?
Ventricular septal hypertrophy below the aortic valve
What happens in the LV with hypertrophic CM?
LV becomes elongated and hypercontractile
What are the other names for hypertrophic cardiomyopathy?
Idiopathic hypertrophic subaortic stenosis
Obstructive hypertrophic cardiomyopathy
Hypertrophic obstructive cardiomyopathy
Asymmetric setup hypertrophy
What occurs with hypertrophic CM and LV outflow?
Dynamic LV outflow obstruction
- present with activity
- absent with rest
Why does activity affect hypertrophic CM?
The strong the heart contracts the hypertrophied septum is pushed out in the way of flow through the aortic valve
-decreasing SV
What is the associated pathology with hypertrophic CM?
Myocardial ischemia not from CAD
Decreased LV compliance because of hypertrophied muscle
Increased LV relaxation time
Why does hypertrophic CM have myocardial ischemia without CAD?
Hypercontractile muscle increases O2 demand
What is the most common genetic CV disease?
Hypertrophic CM
Which cardiomyopathy is seen usually in a young patient and can cause sudden death?
Hypertrophic CM
What symptoms are seen in elder patients with hypertrophic CM?
Angina
Heart failure
When should hypertrophic CM be suspected in a patient with angina?
When usual treatments of angina make symptoms worse
-NTG, diuretics, digoxin
Why do angina treatments make hypertrophic CM worse?
Because dynamic outflow obstruction is worsened by increased contractility and decreased preload
How is hypertrophic CM treated?
BB
CCB
Myocardial depression is beneficial
What is the anesthetic management of hypertrophic CM?
Decrease contractility Increase preload Maintain SVR Avoid tachycardia GA is more manageable than regional
What EF is seen in patients who need a heart transplant?
EF <20%
What is left behind after a heart transplant?
Native atria remnants
What is seen on EKG of heart transplant patients?
Double P waves
-but conduction is normal
What is important to remember about nerves and the transplant heart?
The heart is denervated
- no sympathetic
- no parasympathetic
- no sensory
Why are heart transplant patients at increased infection risk
Immunosuppressants
What is the vagal influence on a transplant heart?
None
- no response to carotid massage, valsalva
- high resting HR
What is the SNS response in a transplanted heart?
Initial response is blunted (quick HR and contractility increase are not seen)
-eventual full response from circulating catecholamines
What increased risk do heart transplant patients have because of a rejection reaction in endothelium?
Increased risk for CAD
-reaction occurs in the coronary endothelium
Why do heart transplant patients have silent ischemia?
No sensory innervation
What routine testing in performed with heart transplant patients because sensory dennervation?
Angiograms
The transplant heart is _______ dependent
Preload
Why is the transplant heart said to be preload dependent?
Because it no longer can respond quickly with an increased HR
So if a heart transplant patient is hypovolemic how does the heart respond?
Hypovolemia does not stimulate a HR increase
What pharmacologic considerations should be remembered with heart transplant patients?
The denervated heart will not have the expected HR changes with: Opioids Anticholinergics Anticholinesterases Pancuronium
What kind of drugs CAN be used to affect the transplanted heart?
Direct acting drugs: Isoproterenol Epinephrine Dobutamine Vasopressin
