HOCM and other things Flashcards
Why does hypertrophic cardiomyopathy cause problems?
LV systolic function is vigorous, but thickened muscle is stiff
Stiff muscle –> impaired relaxation –> high diastolic pressures –> heart failure
Is the hypertrophy in hypertrophic cardiomyopathy symmetric or asymmetric?
Asymmetric, usually focused in septum (asymmetric septal hypertrophy, ASH)
How do the muscle fibers appear in hypertrophic cardiomyopathy?
Myocardial fiber disarray
What proteins are usually mutated in hypertrophic cardiomyopathy?
Sarcomeric proteins
Are all cases of hypertrophic cardiomyopathy obstructive?
NO, some are non-obstructive
What are the symptoms of hypertrophic obstructive cardiomyopathy (HOCM)?
Same as aortic stenosis
- Angina
- Syncope
- Heart failure
What causes the obstruction of the aorta in HOCM?
Anterior leaflet of the mitral valve gets pushed toward outflow tract
Hypertorphied septum means that the edge of the outflow tract is closer to the leaflet, so when it gets pushed over, can essentially obstruct the outflow
What is the movement of the mitral valve in HOCM called?
SAM = systolic anterior motion of the mitral valve
Anterior leaflet bulges toward septum and obstructs flow during systole
What type of murmur will be heard in HOCM?
High velocity flow murmur, crescendo-decrescendo, just like in aortic stenosis
What will occur to the murmur heard in HOCM when contractility is increased?
Murmur will increase in intensity
Increasing contraction brings septum closer to the leaflet, obstructing flow even more
What will occur to the murmur heard in HOCM when preload (volume) is increased?
Murmur will decrease in intensity
Increased volume will make heart bigger, bringing septum further from leaflet, reducing the obstruction of flow
What two classic maneuvers can be used to differentiate the HOCM murmur from aortic stenosis murmur?
Valsalva
Squat
If patient has HOCM, what will happen to the murmur when they Valsalva?
Valsalva will decrease volume back to heart, bringing septum closer to leaflet, increasing obstruction of flow
Murmur will increase in intensity
If patient has aortic stenosis, what will happen to the murmur when they Valsalva?
Valsalva will decrease volume back to heart, decreasing flow across stenotic aorta
Murmur will decrease in intensity
If patient has HOCM, what will happen to the murmur when they squat?
Squat will increase volume back to heart, bringing septum further from leaflet, decreasing obstruction of flow
Murmur will decrease in intensity
Since contractility increases the obstruction in HOCM, what drugs should not be given to these patients?
Inotropes
What is the term for the abnormal carotid pulse seen in HOCM?
Pulsus Bisferiens - twice beating pulse
Initial rapid rise in aortic pressure, but stops as leaflet blocks outflow
Get a second pulse from blood bouncing back against walls
Manifests as “spike and dome” radial pulse
In what condition do you see pulse deficit?
Atrial fibrillation
Not every beat gets good enough diastolic filling to produce a pulse
In what condition do you see pulsus parvus et tardus?
Aortic stenosis
Small and late pulse felt in carotid due to the obstruction
In what condition do you see pulsus paradoxus?
Tamponade
Diminished LV filling causes reduction in systolic BP upon inspiration (inspiration normally causes only mild systolic BP)
What are 2 reasons to get a dilated ventricle?
Poor pump function - “dilated cardiomyopathy”
Think of Frank Starling curve - increase volume to try and maintain stroke volume
Low EF
Volume overload - “dilated heart with good systolic function”
Good EF
How do you know if the rhythm of the heart is sinus?
Positive in Lead 1 and avF (in proper axis)
If you see ST elevation in EKG leads V1-V5, which wall of the heart and which coronary artery are affected?
Anterior wall, LAD
If you see ST elevation in EKG leads 2, 3, and avF, which wall of the heart and which coronary artery are affected?
Inferior, RCA
If you see ST elevation in EKG leads 1, avL, and V6, which wall of the heart and which coronary artery are affected?
Lateral, LCx
How can you determine if it is a RV MI?
Add right precordial leads
What is a first degree AV block?
PR interval >0.2 sec (aka 5 small blocks)
What is a second degree AV block, Mobitz type I (wenckebach)?
PR interval gets longer and longer until QRS is dropped
What is a second degree AV block, Mobitz type II?
PR interval doesn’t change, QRS just randomly dropped
What is a third degree AV block?
No relationship between P wave and QRS, totally divorced
