Myocardial disease

Question 1

LV dysfunction results in __________.

Answer 1

results in progressive remodeling of the ventricular chamber leading to dilation and a low ejection fraction

Question 2

Describ what the hear looks like with the various types of cardiomyopathies?

dilated

hypertrophic

restrictive

Answer 2

Question 3

What are the different forms of dilated cardiomyopathies?

Answer 3

• inflammatory and non-inflammatory

Question 4

What are the early symptoms of inflammatory myocarditis?

What does it progress to?

Answer 4

• Early symptoms
  
  • fatigue
  • dyspnea
  • palpitations
• Progresses to:
  
  • CHF
  • pulsus alterans- beat to beat variability in BP
  • tachycardia
  • pulmonary edema
• *Usually complete recovery after treatment with abx!

Question 5

Non-inflammatory cardiomyopathy usually manifests how? What is it usually cause by?

Answer 5

• Manifests as CHF
• Usually due to:
  
  • toxicity (ETOH)
  • idiopathic process
  • degenerative process
  • infiltrative process
  • post myocardial infarct

Question 6

What are dilated cardiomyopathies usually characterized by?

What is the clinical picutre?

Answer 6

• Characterized by
  
  • elevated filling pressures
  • failure of contractile strength
  • a marked inverse relationship btw arterial impedance stroke vol
• Clinical picture: Forward failure (decreased CO)
  
  • fatigue
  • hypotension
  • oliguria
  • RAAS activated to increase circulating blood volume through Na and water retention

Question 7

What are the differences between Left sided heart failure and right sided heart failure regarding dilated cardiomyopathies

Answer 7

• Left sided HF
  
  • elevated filling pressures requires
  • Secondary mitral regurgitation caused by the dilation of the ventricle; causing orthopnea, pulm edema, and paroxysmal nocturnal dyspnea
• Right sided HF
  
  • hepatomegaly
  • JVD
  • peripheral edema

Question 8

What are the goals for anesthetic management of a patient with HF?

How would you treat hypotension?

Regional ok?

Answer 8

• Goal is to prevent myocardial depression
  
  • HR- normal to elevated
  • Preload- normal to high
  • afterload- low
  • contractility- increased
• Hypotension treated with ephedrine, phenylephrine, vasopressin–avoid fluid overload
• Regional ok

Question 9

What are some of the other names for hypertrophic cardiomyopathy?

Answer 9

• Idiopathic hypertrophic subaortic stenosis (IHSS)- most common
• Asymmetric septal hypertrophy
• Hypertrophic obstructive cardiomyopathy
• Muscular subaortic stenosis

Question 10

What are the clinical features of hypertrophic cardiomyopathy?

Answer 10

• Autosomal dominant trait- main defect is contractile elements of the heart: then an increase in the density of the Ca channels
• majority of pts are asymptomatic, but symptoms include dyspnea, angina, syncope
• 50% patients initially present with sudden death or cardiac arrest (often teens)
• 75% have ventricular dysrhythmias, 25% SVT, 5-10% afib
• anual mortality 3-8% (post op 1-3%)
• Most patients become symptomatic in second and third decades of life

Question 11

What is the pathophysiology of hypertrophic cardiomyopathy?

Answer 11

• Main features of pathophysiology:
  
  • myocardial hypertrophy
  • Rapid LV ejection (80% in early systole)
  • dynamic left ventricular out flow tract obstruction
  • systolic anterior movement of mitral valve, causing regurgitation
  • diastolic dysfunction- can’t relax, doesnt fill well
  • sub-aortic pressure gradient
  • myocardial ischemia

Question 12

What can make the LV outflow obstruction seen in hypertrophic cardiomyopathy worse?

Answer 12

• decreased preload
  
  • dehydration
• decreased afterload
• increased contractility
  
  • exercise
• **These reasons are why teenagers with hypertrophic cardiomyopathy can drop dead while exercising

Question 13

What factors may impair contractility but improve systolic function in a pt with hypertrophic cardiomyopathy?

Answer 13

• volume loading
• vasoconstriction
• myocardial depression
  
  • increased inhaled agents, these pts like this

Question 14

Why may vasodilators be problematic for patients with Hypertrophic cardiomyopathy?

Answer 14

• Most pts with hypertrophic cardiomyopathy have some degree of mitral regurg, which can be worsened with vasodilators
• Vasoconstrictors attenuate obstruction and decrease the mitral regurgitation

Question 15

Generally speaking, how do we treat patients with hypertrophic cardiomyopathies?

Answer 15

• lots of gas
• fluid loading
• vasoconstriction

Question 16

How is hypertrophic cardiomyopathy medically managed?

Answer 16

• Beta blockers-
  
  • blunt sympathetically mediated increases in subaortic stenosis
  • decrease tachyarrhythmias
• Calcium channel blockers
  
  • improve diastolic relaxation

Question 17

What are the ECHO findings in a pt with hypertrophic cardiomyopathy?

How is it managed surgically?

Answer 17

• Echo findings:
  
  • thickened interventricular septum (IVS)
  • poor septal motion
  • anterior displacement of the mitral valve
• Surgical treatment:
  
  • myomectomy

Question 18

What is the anesthetic management for a patient with IHSS?

Answer 18

• IA are good because they decrease contractility
• A-line- b/c of high risk of dysrhythmias
• treat hypotension with alpha adrenergic agonists (phenylephrine) and volume
  
  • avoid ephedrine
• Beta adrenergic agonists are contraindicated
• promptly replace blood and fluids
• avoid vasodilators
• maintain NSR