Myocardial Diseases Flashcards
What are cardiomyopathies? What is the difference between primary and secondary?
They are myocardial disorders in which the heart muscle is structurally or functionally abnormal.
Primary cardiomyopathy is in the absence of CAD, hypertension, valvular diseas and CHD.
Secondary is myocardial dysfunction secondary to a specific disease like CAD, hypertension, CHD, valvular disease.
If the myocardial dysfunction is systolic, there will be impaired _________ of the ventricle and decreased __________.
If the myocardial dysfunction is diastolic, there will be impaired__________ of the ventricle resulting in decreased ___________ and elevated __________.
Systolic- impaired contraction of the ventricle with decreased EF.
Diastolic- impaired compliance of the ventricle with decreased filling and elevated filling pressures.
What are the 3 broad categories of cardiomyopathies we are responsible for?
- Dilated
- Restrictive (usually grouped with constrictive pericarditis)
- Hypertrophic
Dilated cardiomyopathy is defined by _________ and reduced ____________ function in the absence of _____________ OR _______________.
LV dilation and reduced systolic function in the absence of:
- abnormal loading conditions (valve dysfunction, hypertension)
- CAD with global systolic impairment
Most cases of dilated cardiomyopathy are considered _________ although there is suspicion they are related to ________ due to the fact that a lot of patients have ________________ 2-4 wks before symptoms of cardiac dysfunction.
idiopathic but there is suspicion they are viral due to the fact that patients have prodromal upper respiratory tract infections 2-4 wks prior to cardiac symptoms
What are the “known” (not idiopathic) causes of dilated cardiomyopathy?
- Toxins- alcohol, anthracyclines
- Inflammation- peripartum/ post-partum
- Infections - HIV, viral, Chaga’s (try. cruzi)
- Familial
What are the 2 types of dilated cardiomyopathies that can be “inherited”?
What is an example of an inherited dilated cardiomyopathy?
- disorders of metabolism- FA oxidation, mitochondrial oxidative phosphorylation
- disorders of structural or contractile myocardial proteins
Duchennes or Beckers muscular dystrophy due to the absence of dystrophin
What 4 symptoms are associated with LHF due to dilated cardiomyopathy?
- DOE
- nocturnal paroxysmal dyspnea
- othopnea
- shortness of breath
What are the 3 symptoms associated with RHF due to dilated cardiomyopathy?
- pedal edema
- increased abdominal girth (ascites)
- anorexia/nausea (mesenteric/hepatic congestion)
What 2 symptoms are associated with a low output state due to dilated cardiomyopathy?
- Fatigue
2. Exertional dyspnea
What are the 3 initial physical exam findings for dilated cardiomyopathy?
- Tachycardia (reflex due to decreased CO)
- Low pulse pressure (decreased systolic pressure/increased diastolic pressure)
- elevated jugular veins (tricuspid regurgitation)
What might dilated cardiomyopathy cause distented jugular veins and an increased V wave?
When the ventricles dilate, they stretch the tricuspid and mitral valves making them regurgitant.
This increases RA and LA filling during ventricular systole. This will increase their pressure and elevated the jugular veins because less flow will be able to go into the high pressure RA/
What are the auscultation findings on someone with dilated cardiomyopathy?
- S3 or S4
- murmurs from mitral and tricuspid regurgitation
- Lateral PMI
LVEF has good prognostic implications for what 3 diseases?
What is it NOT a good prognostic indicator for?
It is good for patients with:
- CAD
- valvular disease
- congenital heart disease
In CHF and low LVEF, the LVEF is NOT a good prognostic indicator for predicting who will have progressive symptoms and thus need transplant
What is the best indicator of short term prognosis in patients with symptomatic systolic dysfunction?
Maximal O2 consumption - objective measure of systemic oxygen delivery at peak exercise
(symptom class and functional abilities are good, but not the best)
If dilated myopathy is not caught early and is allowed to progress, what are the 3 most serious outcomes?
- lethal arrhythmias (ventricular) and sudden cardiac death
- progressive heart failure (most common COD)
- thromboembolytic events
Where are the 2 highest incident embolytic events due to dilated cardiomyopathy?
- Cerebrovascular (stroke)
2. pulmonary
What does the CXR show on a person with dilated cardiomyopathy?
- cardiomegaly
2. pulmonary vascular congestion
Describe the EKG of someone with dilated cardiomyopathy.
- sinus tachycardia
- atrial or ventricular ectopy, A fib
- non-specific ST-T wave abnormalities
- Q waves in ant/inf leads (“pseudo MI”
What is the method of diagnosis for dilated cardiomyopathy?
Echo-
- chamber dilation (all 4)
- poorly contracting ventricles
- thrombi in ventricle apex
- MR or TR
What can an MRI and nuclear scans tell us about the heart in dilated cardiomyopathy?
They can quantify the LVEF
What can cardiac cath tell us about the heart in dilated cardiomyopathy?
Intracardiac filling pressures
What test is NOT helpful for diagnosing dilated cardiomyopathies?
Endomyocardial biopsy- diagnostic yield is low and risk of biopsy is high (can disrupt conduction and perforate chambers)
If you see dilated heart chambers on echo, what are potential diagnoses?
- silent MI or ischemia
- valvular stenosis or regurgitation
- L to R shunting (ASD, VSD, PDA)
- Dilated cardiomyopathy
- renal failure, infection, hypersensitivity, vasculitis
Hypertrophic cardiomyopathy is characterized by _______________ resulting in impaired ________.
This occurs in the absence of ________________
inappropriate LV hypertrophy resulting in impaired diastolic function (impaired filling due to stiff ventricle)
This occurs in the absence of hypertension or aortic valve stenosis
What are the 2 characteristic types of LVH due to hypertrophic cardiomyopathy?
- Concentric - all the walls of the ventricle are equally hypertrophied
- Asymmetric- the interventricular septum is huge OR just the free wall is huge OR just the apex is huge
What are the 3 different areas that can be thickened in asymmetric LVH?
Which causes dynamic obstruction of the LV?
- interventricular septum- dynamic obstruction of LV
- Apex
- free wall
_________________ hypertrophic cardiomyopathy accounts for 75% of cases where only 25% are _____________.
Non-obstructive = 75%
Obstructive (asymmetric septal hypertrophy ASH) (idiopathic hypertrophic subaortic stenosis)
What are the 3 characteristic features of obstructive hypertrophic cardiomyopathy?
- thickened and asymmetric septum (>1.3x the thickness of free wall)
- abnormal movement of anterior mitral valve leaflet in ventricular systole
- cavity obliteration in systole
What 2 things make obstruction worse in obstructive hypertrophic cardiomyopathy?
- decreased ventricular cavity size - valsalva/nitrates
2. increase in LV contractility
What 2 things make obstruction better in obstructive hypertrophic cardiomyopathy?
- increased ventricle cavity size- squatting, isometric hand grip
- decreased ventricle contraction
What causes familial hypertrophic cardiomyopathy?
Autosomal dominant inheritance with mutations in sarcomeric proteins. Genes mutations are in: 1. B-myosin heavy chain gene 2. troponin I 3. tropomysin 4 actin
How does hypertrophic cardiomyopathy lead to pulmonary congestion and edema?
- abnormal diastolic relaxation (stiff LV)
- increased LV EDP
- increased LV pressure
- pulmonary congestion and dyspnea (despite normal LV systolic function)
What are the MOST COMMON presenting symptoms for hypertrophic cardiomyopathy?
- dyspnea, orthopnea and paroxysmal nocturnal dyspnea (resulting from increased EDP which increases LA pressure which increases pulmonary venous pressure)
- Angina- inadequate flow to thick myocardium
- Syncope- due to decreased CO because of the obstruction
- Palpitations
A high school athletes has sudden cardiac death while playing basketball.
What is the most likely problem?
What gene is likely mutated?
They probably have hypertrophic cardiomyopathy (obstructive)
The increased heart rate of sports decreased diastole (less coronary artery filling) and the myocardium is too thick to be supplied.
They have ventricular arrhythmia and die.
The gene that is mutated is likely the B-myosin heavy chain gene.
What is the carotid pulse going to show for someone with an obstructive hypertrophic cardiomyopathy?
They will likely have a bisferiens pulse. There will be a brisk upstroke, decrease, then second upstroke due to displacement of the obstruction.
What is heard on auscultation for someone with obstructive hypertrophic cardiomyopathy?
- forceful and laterally displace PMI
- S4 may be palpable
- systolic thrill along left sternal border
- harsh crescendo-decrescendo systolic murmur on left sternal border that gets more intense with reduction of ventricle cavity size or increased contraction
How can you tell the difference between the murmur of aortic stenosis and that of obstructive hypertrophic cardiomyopathy?
Both are harsh crescendo-decrescendo systolic murmurs.
Aortic stenosis- radiates to the carotids, has a systolic ejection click and does not change in intensity
OHC- radiates to the base of the heart, no systolic ejection click, gets louder with Valsalva, nitrates, standing, increased contractility and gets less intense with squatting, isometric hold and decreased contractility.
How has the highest annual mortality from hypertrophic cardiomyopathy?
What are factors that increase risk?
When is death likely to occur?
Children (6%) vs. only 3% in adults.
Risk is increased in patients with family history of:
- syncope
- sudden death
- ventricular arrhythmias
- alpha tropomyosin gene defect
Death occurs usually during exercise.
Mortality is NOT related to the presence or severity of outflow tract obstruction
What 4 progressions worsen the symptoms in patients with hypertrophic cardiomyopathies?
- increased hypertrophy
- development of A fib
- increased mitral regurgitation
- 10-15% of patients get dilated cardiomyopathy too
What is seen on the EKG for someone with hypertrophic cardiomyopathy?
- LVH
- Q waves on inf/lateral leads due to septal hypertrophy
- inverted T waves in precordial leads
- poor R wave progression across precordial leads
What is seen on Echo of someone with hypertrophic cardiomyopathy?
What 2 additional things are noted if they have HOCM?
If echo is unavailable, what should you use to assess HCM?
- LV hypertrophy
- normal LVEF
- LV outflow obstruction and MR
HOCM:
- septum:free wall 1.3:1
- systolic anterior motion of mitral valve
MRI and CT to assess LV mass and asymmetric hypertrophy
What is the buzzword characteristic shape for the LV in patients with asymmetric septal hypertrophy?
Asymmetric apex form?
Septal - banana shaped LV
Apex- spade LV
What are the drugs used for treatment of HCM?
- diuretics - decrease pulmonary congestion BUT can worsen dynamic outflow obstruction
- B-blocker, CCB- improve relaxation in diastole and decrease LV outflow gradient in HOCM
- Amiodarone if they have arrhythmias
What are the 2 invasive techniques used to decrease septal hypertrophy in HOCM?
What is the drawback to these?
- cardiac cath induces septal MI to thin out the wall
- surgery resects some of the bulk of the muscle
These can cause A fib.
